[Federal Register Volume 71, Number 200 (Tuesday, October 17, 2006)]
[Rules and Regulations]
[Pages 61236-61328]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-8478]
[[Page 61235]]
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Part III
Environmental Protection Agency
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40 CFR Parts 53 and 58
Revisions to Ambient Air Monitoring Regulations; Final Rule
Federal Register / Vol. 71, No. 200 / Tuesday, October 17, 2006 /
Rules and Regulations
[[Page 61236]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 53 and 58
[EPA-HQ-OAR-2004-0018; FRL-8227-2]
RIN 2060-AJ25
Revisions to Ambient Air Monitoring Regulations
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: The EPA is issuing final amendments to the ambient air
monitoring requirements for criteria pollutants. The purpose of the
amendments is to enhance ambient air quality monitoring to better serve
current and future air quality management and research needs. The final
amendments establish limited ambient air monitoring requirements for
thoracic coarse particles in the size range of PM10-2.5 to
support continued research into these particles' distribution, sources,
and health effects. The ambient air monitoring amendments also require
each State to operate one to three monitoring stations that take an
integrated, multipollutant approach to ambient air monitoring. In
addition, the final amendments modify the general monitoring network
design requirements for minimum numbers of ambient air monitors to
focus on populated areas with air quality problems and to reduce
significantly the requirements for criteria pollutant monitors that
have measured ambient air concentrations well below the applicable
National Ambient Air Quality Standards. These amendments also revise
certain provisions regarding monitoring network descriptions and
periodic assessments, quality assurance, and data certifications. A
number of the amendments relate specifically to PM2.5,
revising the requirements for reference and equivalent method
determinations (including specifications and test procedures) for fine
particle monitors.
DATES: This final rule is effective on December 18, 2006.
ADDRESSES: The EPA has established a docket for this action under
Docket ID No. EPA-HQ-OAR-2004-0018. All documents in the docket are
listed in the http://www.regulations.gov index. Although listed in the
index, some information is not publicly available, e.g., confidential
business information or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, will be publicly available only in hard copy. Publicly
available docket materials are available either electronically in
http://www.regulations.gov or in hard copy at the Revisions to the
Ambient Air Monitoring Regulations Docket, EPA/DC, EPA West, Room B102,
1301 Constitution Ave., NW., Washington, DC. The Public Reading Room is
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding
legal holidays. The telephone number for the Public Reading Room is
(202) 566-1744, and the telephone number for the Air Docket is (202)
566-1742.
Note: The EPA Docket Center suffered damage due to flooding
during the last week of June 2006. The Docket Center is continuing
to operate. However, during the cleanup, there will be temporary
changes to Docket Center telephone numbers, addresses, and hours of
operation for people who wish to visit the Public Reading Room to
view documents. Consult EPA's Federal Register notice at 71 FR 38147
(July 5, 2006) or the EPA Web site at http://www.epa.gov/epahome/dockets.htm for current information on docket status, locations, and
telephone numbers.
FOR FURTHER INFORMATION CONTACT: For general questions concerning the
final amendments, please contact Mr. Lewis Weinstock, U.S. EPA, Office
of Air Quality Planning and Standards, Air Quality Assessment Division,
Ambient Air Monitoring Group (C304-06), Research Triangle Park, North
Carolina 27711; telephone number: (919) 541-3661; fax number: (919)
541-1903; e-mail address: [email protected]. For technical
questions, please contact Mr. Tim Hanley, U.S. EPA, Office of Air
Quality Planning and Standards, Air Quality Assessment Division,
Ambient Air Monitoring Group (C304-06), Research Triangle Park, North
Carolina 27711; telephone number: (919) 541-4417; fax number: (919)
541-1903; e-mail address: [email protected].
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this action apply to me?
Categories and entities potentially regulated by this action
include:
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Category NAICS code \1\ Examples of regulated entities
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Industry..................................... 334513, 541380 Manufacturer, supplier, distributor, or vendor
of ambient air monitoring instruments;
analytical laboratories or other monitoring
organizations that elect to submit an
application for a reference or equivalent
method determination under 40 CFR part 53.
Federal government........................... 924110 Federal agencies (that conduct ambient air
monitoring similar to that conducted by States
under 40 CFR part 58 and that wish EPA to use
their monitoring data in the same manner as
State data) or that elect to submit an
application for a reference or equivalent
method determination under 40 CFR part 53.
State/territorial/local/tribal government.... 924110 State, territorial, and local, air quality
management programs that are responsible for
ambient air monitoring under 40 CFR part 58 or
that elect to submit an application for a
reference or equivalent method determination
under 40 CFR part 53 or for an approved
regional method approved under 40 CFR part 58
appendix C. The proposal also may affect
Tribes that conduct ambient air monitoring
similar to that conducted by States and that
wish EPA to use their monitoring data in the
same manner as State monitoring data.
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\1\ North American Industry Classification System.
This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be regulated by this
action. This table lists the types of entities that EPA is now aware
could potentially be regulated by this action. Other types of entities
not listed in the table could also be regulated. To determine whether
your facility or Federal, State, local, or territorial agency is
regulated by this action, you should carefully examine the requirements
for reference or equivalent method determinations in 40 CFR part 53,
subpart A (General
[[Page 61237]]
Provisions) and the applicability criteria in 40 CFR 51.1 of EPA's
requirements for State implementation plans. If you have questions
regarding the applicability of this action to a particular entity,
consult the person listed in the preceding FOR FURTHER INFORMATION
CONTACT section.
B. Where can I obtain a copy of this action?
In addition to being available in the docket, an electronic copy of
this final action will also be available on the Worldwide Web (WWW)
through the Technology Transfer Network (TTN). Following the
Administrator's signature, a copy of the final amendments will be
placed on the TTN's policy and guidance page for newly proposed or
promulgated rules at http://www.epa.gov/ttn/oarpg. The TTN provides
information and technology exchange in various areas of air pollution
control.
C. Public Comments on Proposed Amendments
EPA received approximately 20,000 public comments on the proposed
amendments to the ambient air monitoring regulations during the 90-day
comment period. These comments were submitted to the rulemaking docket
and also during public hearings held in Chicago, Illinois;
Philadelphia, Pennsylvania; and San Francisco, California (71 FR 8228,
February 16, 2006). Public comments on the proposed amendments were
submitted by States, local governments, Tribes, and related
associations; energy, mining, ranching, and agricultural interests and
related associations; vendors, laboratories, and technical consultants;
health, environmental, and public interest organizations; and private
citizens. The EPA has carefully considered these comments in developing
the final amendments. Summaries of these comments and EPA's detailed
responses are contained in the Response to Comments document included
in the docket.
D. Judicial Review
Under section 307(b)(1) of the Clean Air Act (CAA), judicial review
of the final amendments is available only by filing a petition for
review in the U.S. Court of Appeals for the District of Columbia
Circuit by December 18, 2006. Under section 307(d)(7)(B) of the CAA,
only an objection to the final amendments that was raised with
reasonable specificity during the period for public comment can be
raised during judicial review. Moreover, under section 307(b)(2) of the
CAA, the requirements established by the final amendments may not be
challenged separately in any civil or criminal proceedings brought by
EPA to enforce these requirements.
E. Peer Review
The EPA sought expert scientific review of the proposed methods,
technologies, and approach for ambient air monitoring by the Clean Air
Scientific Advisory Committee (CASAC). The CASAC is a Federal advisory
committee established to review scientific and technical information
and make recommendations to the EPA Administrator on issues related to
the air quality criteria and corresponding NAAQS. CASAC formed a
National Ambient Air Monitoring Strategy (NAAMS) Subcommittee in 2003
to provide advice for a strategy for the national ambient air
monitoring programs. This subcommittee, which operated over a 1-year
period, and a new subcommittee on Ambient Air Monitoring and Methods
(AAMM), formed in 2004, provided the input for CASAC on its
consultations, advisories, and peer-reviewed recommendations to the EPA
Administrator.
In July 2003, the CASAC NAAMS Subcommittee held a public meeting to
review EPA's draft National Ambient Air Monitoring Strategy document
(dated September 6, 2002), which contained technical information
underlying planned changes to the ambient air monitoring networks. The
EPA continued to consult with the CASAC AAMM Subcommittee throughout
the development of the proposed amendments. Public meetings were held
in July 2004, December 2004, and September 2005 to discuss the CASAC
review of nearly 20 documents concerning methods and technology for
measurement of particulate matter (PM); data quality objectives for PM
monitoring networks and related performance-based standards for
approval of equivalent continuous PM monitors; configuration of ambient
air monitoring stations; \1\ and other technical aspects of the
proposed amendments. These documents, along with CASAC review comments
and other information are available at: http://www.epa.gov/ttn/amtic/casacinf.html.
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\1\ ``Station'' and ``site'' are used somewhat interchangeably
in this notice of final rulemaking. When there is a difference
(which will be apparent from context), ``site'' generally refers to
the location of a monitor, while ``station'' refers to a suite of
measurements at a particular site.
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F. How is this document organized?
The information presented in this preamble is organized as follows:
I. General Information
A. Does this action apply to me?
B. Where can I obtain a copy of this action?
C. Public Comments on Proposed Amendments
D. Judicial Review
E. Peer Review
F. How is this document organized?
II. Authority
III. Overview
A. Summary of Concurrent Final Action on Revisions to the
National Ambient Air Quality Standards for Particulate Matter
B. Summary of Changes to Ambient Air Monitoring Regulations
C. Significant Dates for States, Local Governments, Tribes, and
Other Stakeholders
D. Implementation of the Revised Monitoring Requirements
E. Federal Funding for Ambient Air Monitoring
IV. Discussion of Regulatory Revisions and Major Comments on
Proposed Amendments to 40 CFR Part 53
A. Overview of Part 53 Regulatory Requirements
B. Requirements for Candidate Reference Methods for
PM10-2.5
C. Requirements for Candidate Equivalent Methods
PM2.5 and PM10-2.5
D. Other Changes
V. Discussion of Regulatory Revisions and Major Comments on Proposed
Amendments to 40 CFR Part 58
A. Overview of Part 58 Regulatory Requirements
B. General Monitoring Requirements
1. Definitions and Terminology
2. Annual Monitoring Network Plan and Periodic Network
Assessment
3. Operating Schedules
4. Monitoring Network Completion for PM10-2.5 and
NCore Sites
5. System Modifications
6. Annual Air Monitoring Data Certification
7. Data Submittal
8. Special Purpose Monitors
9. Special Considerations for Data Comparisons to the National
Ambient Air Quality Standards
C. Appendix A--Quality Assurance Requirements for State and
Local Air Monitoring Stations and Prevention of Significant
Deterioration Air Monitoring
1. General Quality Assurance Requirements
2. Specific Requirements for PM10-2.5,
PM2.5, PM10, and Total Suspended Particulates
3. Particulate Matter Performance Evaluation Program and
National Performance Audit Programs
4. Revisions to Precision and Bias Statistics
5. Other Program Updates
D. Appendix C--Ambient Air Quality Monitoring Methodology
1. Applicability of Federal Reference Methods and Federal
Equivalent Methods
2. Approved Regional Methods for PM2.5
E. Appendix D--Network Design Criteria for Ambient Air Quality
Monitoring
1. Requirements for Operation of Multipollutant NCore Stations
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2. Requirements for Operation of PM10-2.5 Stations
3. Requirements for Operation of PM2.5 Stations
4. Requirements for Operation of PM10 Stations
5. Requirements for Operation of Carbon Monoxide, Sulfur
Dioxide, Nitrogen Dioxide, and Lead Monitoring Sites
6. Requirements for Operation of Ozone Stations
7. Requirements for Operation of Photochemical Assessment
Monitoring Stations
F. Appendix E--Probe and Monitoring Path Siting Criteria for
Ambient Air Monitoring
1. Vertical Placement of PM10-2.5 Samplers
2. Ozone Monitor Setback Requirement from Roads
G. Sample Retention Requirements
H. Deletion of Appendices B and F
VI. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
G. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
H. Executive Order 12898: Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations
I. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
J. National Technology Transfer Advancement Act
K. Congressional Review Act
II. Authority
The EPA rules for ambient air monitoring are authorized under
sections 110, 301(a), and 319 of the Clean Air Act (CAA). Section
110(a)(2)(B) of the CAA requires that each State implementation plan
(SIP) provide for the establishment and operation of devices, methods,
systems, and procedures needed to monitor, compile, and analyze data on
ambient air quality and for the reporting of air quality data to EPA.
Section 103 authorizes, among others, research and investigations
relating to the causes, effects, extent, prevention and control of air
pollution. Section 301(a) of the CAA authorizes EPA to develop
regulations needed to carry out EPA's mission and establishes
rulemaking requirements. Uniform criteria to be followed when measuring
air quality and provisions for daily air pollution index reporting are
required by CAA section 319.
III. Overview
A. Summary of Concurrent Final Action on Revisions to the National
Ambient Air Quality Standards for Particulate Matter
Elsewhere in this Federal Register, EPA is finalizing revisions to
the National Ambient Air Quality Standards (NAAQS) for particulate
matter (PM). These revisions were proposed on January 17, 2006 (71 FR
2620). For a detailed explanation of these revisions, see that preamble
elsewhere in this Federal Register.
The EPA is finalizing the PM2.5 NAAQS revisions as
proposed. With regard to the primary standards for fine particles
(generally referring to particles less than or equal to 2.5 micrometers
([mu]m) in diameter, PM2.5), EPA is revising the level of
the 24-hour PM2.5 standard to 35 micrograms per cubic meter
([mu]g/m\3\), providing increased protection against health effects
associated with short-term exposure (including premature mortality and
increased hospital admissions and emergency room visits). The EPA is
retaining the level of the annual PM2.5 standard at 15
[mu]g/m\3\, continuing protection against health effects associated
with long-term exposure (including premature mortality and development
of chronic respiratory disease). The EPA is also finalizing the
proposed revisions in the conditions under which spatial averaging of
the annual primary PM2.5 NAAQS is permitted, and placing
these conditions in appendix N of 40 CFR part 50 rather than in
appendix D of 40 CFR part 58.
With regard to secondary PM standards, EPA is revising the current
24-hour PM2.5 secondary standard by making it identical to
the revised 24-hour PM2.5 primary standard, retaining the
annual PM2.5 and 24-hour PM10 secondary
standards, and revoking the annual PM10 secondary standard.
This suite of secondary PM standards is intended to provide protection
against PM-related public welfare effects, including visibility
impairment, effects on vegetation and ecosystems, and materials damage
and soiling.
The EPA is finalizing the proposed Federal reference method (FRM)
for PM2.5. This action in essence codifies certain desirable
features that have already been in widespread use as elements of
approved equivalent methods or national user modifications.
The EPA is not finalizing the proposed NAAQS for
PM10-2.5, for reasons explained in the accompanying preamble
to the revisions to the NAAQS. As a result, EPA is not finalizing a
number of related provisions (notably those which would have prescribed
which monitors could have been used for comparison with that proposed
NAAQS) proposed as amendments to 40 CFR part 58. The EPA is, however,
finalizing the proposed FRM for PM10-2.5 (see appendix O to
40 CFR part 50). This FRM is based on paired filter-based samplers for
PM2.5 and PM10 and it will serve as the standard
of reference for measurements of PM10-2.5 concentrations in
ambient air. This should provide a basis for approving Federal
Equivalent Methods (FEMs) and promote the gathering of scientific data
to support future reviews of the PM NAAQS. Because it is a filter based
system, this method can itself be used to provide speciated data. The
reference measurement from the PM10-2.5 FRM is also
important in the development of alternative PM10-2.5
speciation samplers such as dichotomous samplers. The EPA will be
issuing guidance to ensure the use of a consistent national approach
for speciated coarse particle monitors as soon as possible.
In conjunction with the above NAAQS revisions and FRM provisions,
as part of this final monitoring rule, as described below EPA is
finalizing certain provisions which support collection of additional
high quality data on ambient concentrations of PM10-2.5.
These data should be useful in improving the understanding of
PM10-2.5 air quality and in conducting future reviews of the
PM NAAQS.
As explained in the preamble to the NAAQS revisions, EPA is
revoking the annual NAAQS for particles generally less than or equal to
10 [mu]m in diameter (PM10). However, EPA is retaining the
24-hour PM10 NAAQS as a standard for short-term exposure to
thoracic coarse particles, rather than revoking that standard in all
but 15 areas as proposed. This change from the NAAQS revision proposal
necessitates that the final monitoring rule restore certain
PM10 monitoring provisions that were proposed for removal.
B. Summary of Changes to Ambient Air Monitoring Regulations
This rule, in most respects, finalizes the proposals put forth in
the January 17, 2006, notice of proposed rulemaking (71 FR 2710). This
final rule will facilitate monitoring program changes envisioned in the
draft National Ambient Air Monitoring Strategy which was fully
described in the proposal. These final changes, which apply to the
monitoring program for all of the criteria pollutants, will reduce the
required scale of monitoring for pollutants for which most areas have
reached
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attainment. The changes are intended to better focus monitoring
resources on current air quality challenges. The changes will also
allow States and local monitoring agencies more flexibility to design
their monitoring programs to reflect local conditions.
In amendments to 40 CFR part 53 (Reference and Equivalent Methods),
this final rule incorporates the proposed criteria for approval of
Federal equivalent methods (FEM) for PM2.5, with some
modifications to the method testing requirements and approval criteria
in response to persuasive public comments. The modifications will
require a more robust set of testing conditions and closer performance
matching of candidate FEMs to FRMs. The EPA is also finalizing the rule
with some strengthening revisions to the proposed criteria for approved
regional methods (ARMs) for PM2.5. The new criteria for
PM2.5 FEMs and ARMs will facilitate the commercialization
and EPA approval of continuous PM2.5 mass monitors, allowing
them to be substituted for many of the currently operating filter-based
FRMs, which will support additional monitoring objectives and reduce
annual monitoring costs.
In other amendments to 40 CFR part 53, EPA is adopting FEM approval
criteria for PM10-2.5, with some revisions from the proposal
that will provide for approval and use of methods that can meet
multiple monitoring objectives. The new FEM performance criteria for
PM10-2.5 will facilitate approval of filter-based methods
for direct sampling of PM10-2.5 concentrations that can be
chemically speciated using post-sampling laboratory analysis. The FEM
criteria are also expected to encourage commercialization of highly
time-resolved continuous methods. The EPA is hopeful that the
PM2.5 and PM10-2.5 FEM criteria together will
result in the approval and commercialization of methods that provide
equivalent measurements of PM2.5, PM10, and
PM10-2.5 from a single instrument.
In amendments to 40 CFR part 58 (Ambient Air Quality Surveillance),
this final rule, as proposed, requires States to establish and operate
a network of NCore multipollutant monitoring stations. The EPA intends
the NCore network to consist of approximately 75 stations, of which the
rule requires between 62 and 71 such stations. These stations must be
operational by 2011. Most States, as well as the District of Columbia,
Puerto Rico, and the Virgin Islands, will be required to operate a
single station. California, Florida, Illinois, Michigan, New York,
North Carolina, Ohio, Pennsylvania, and Texas will be required to
operate two or three NCore stations. For these States, the selection
between two or three stations will be part of the development and
approval of the NCore monitoring plan that is due by July 1, 2009. The
EPA also plans to negotiate with a number of States, local agencies,
and/or Tribes to operate additional NCore stations on a voluntary
basis, bringing the total number of stations to about 75. By approving
some required stations to be in rural areas and by negotiating for
additional voluntary sites in rural areas, EPA expects that about 55
NCore sites will be in urbanized areas and about 20 in rural areas. The
rural sites are intended to be sited away from any large local emission
sources, so that they represent ambient concentrations over an
extensive area. The NCore stations must perform the types of pollutant
measurements that were proposed, with three exceptions.
PM10-2.5 measurements may be made on a 1-in-3 day schedule
rather than the proposed every day schedule, NOy \2\
measurements may be waived by the EPA Administrator based on certain
criteria, and as explained later in this section, PM10-2.5
chemical speciation will be required in addition to PM10-2.5
mass concentration measurements.
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\2\ NOy refers to a broad class of nitrogen-
containing reactive compounds in ambient air, explained in more
detail in sections V.E.1 and V.E.7 of this preamble.
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The EPA estimated that the proposed rule would have required States
to operate about 225 PM10-2.5 monitors based on the
population and estimated PM10-2.5 concentrations of
metropolitan statistical areas (MSAs) with populations of 100,000 or
more. In addition, PM10-2.5 monitors were proposed to be
required at NCore stations; some monitors likely would have satisfied
both of these requirements. Because EPA is not adopting a NAAQS for
PM10-2.5, the final monitoring rule does not include the
proposed requirement for the broad network of PM10-2.5
monitoring stations in MSAs over 100,000 population. However, the final
monitoring rule does require PM10-2.5 monitors at the
required NCore multipollutant monitoring stations. The data gathered
from these stations should be useful in improving understanding of
PM10-2.5 air quality and in conducting future reviews of the
PM NAAQS. The EPA anticipates that due to natural variations among the
cities and rural areas where the NCore stations will be sited, the
NCore PM10-2.5 monitors will represent a range of
concentrations and nearby emission source types, and that many but not
all will be in well populated locations.
The EPA is not adopting the proposed population-based and
population density-based siting requirements for PM10-2.5
monitors, or any part of the proposed five-part suitability test for
PM10-2.5 monitoring sites, which as proposed would have
controlled whether PM10-2.5 data from a monitoring site
could be compared to the proposed PM10-2.5 NAAQS. These
proposed requirements were tied to the establishment of a
PM10-2.5 NAAQS with a qualified PM10-2.5
indicator based on a determination of whether ambient mixes of coarse
particles are or are not dominated by coarse particle emissions from
enumerated types of sources. Since EPA is not adopting this part of the
proposal, these issues are now moot. In the absence of a
PM10-2.5 NAAQS, our goal nevertheless will be to locate
PM10-2.5 monitors in a manner that satisfies an objective of
the proposed rule, which was to focus most monitoring resources on
population centers.
This final rule contains a requirement for PM10-2.5
speciation to be conducted at NCore multipollutant monitoring stations.
The EPA had proposed a requirement for PM10-2.5 speciation
in 25 areas, with the areas required to have this monitoring selected
based on having a Metropolitan Statistical Area (MSA) population over
500,000 and having an estimated design value of greater than 80 percent
of the proposed PM10-2.5 NAAQS. This would have concentrated
the PM10-2.5 speciation monitoring in areas that have high
populations and high exposures to PM10-2.5. Since EPA is
requiring PM10-2.5 monitoring at NCore primarily for
scientific purposes, it is more appropriate to have monitoring in a
variety of urban and rural locations to increase the diversity of areas
for which chemical species data will be available to use in scientific
studies. The EPA had already proposed to require chemical speciation
for PM2.5 at NCore stations. The collocation of both
PM10-2.5 and PM2.5 speciation monitoring at NCore
stations is consistent with the multipollutant objectives of the NCore
network and will support further research in understanding the chemical
composition and sources of PM10, PM10-2.5, and
PM2.5 at a variety of urban and rural locations. The EPA
will work with States to ensure that PM10-2.5 speciation
monitors employ the latest in speciation technology to advance the
science so that future regulation will provide more targeted protection
against the effects only of those coarse particles
[[Page 61240]]
and related source emissions that prove to be of concern to public
health.
Because the 24-hour PM10 NAAQS is being retained in all
parts of the country, this final rule retains the existing minimum
monitoring network design requirements for PM10. These
longstanding requirements are based on the population of a MSA and its
historical PM10 air quality. For any given combination of
these two parameters, a range of required monitors is prescribed, with
the required number to be determined as part of the annual monitoring
plan. The EPA estimates that once States and Regional Administrators
have considered how current population data and recent PM10
air quality affect the required number of PM10 monitors in
each area, between 200 and 500 FRM/FEM monitors will be required,
compared to about 1,200 in operation now. While States may of course
choose to continue to operate monitors in excess of the minimum
requirements, EPA notes that many PM10 monitors have been
recording concentrations well below the PM10 NAAQS and are
candidates for discontinuation at a State's initiative. States may
choose to retain PM10 monitors that are recording
concentrations below the PM10 NAAQS level to support
monitoring objectives other than attainment/nonattainment
determinations, such as baseline monitoring for prevention of
significant deterioration permitting or public information.
This final rule changes the requirements for the minimum number of
monitors for PM2.5 and ozone (O3) monitoring
networks. In response to comments, the final requirements require more
O3 and PM2.5 monitoring in more polluted areas
and more monitors in CSAs than was proposed. While this final rule
requires fewer monitors than are now operating for O3 and
PM2.5, as did the pre-existing monitoring rule, EPA does not
intend to encourage net reductions in the number of O3 and
PM2.5 monitoring sites in the U.S. as a whole. The surplus
in the existing networks relative to minimum requirements gives States
more flexibility to choose where to apply monitoring resources for
O3 and PM2.5. For PM2.5, this final
rule requires that sampling be conducted on a daily basis for monitors
that have recently been recording the highest concentrations in their
area and have been recording concentrations very near the 24-hour
NAAQS, to avoid a bias in attainment/nonattainment designations that
can occur with less frequent sampling. Pursuant to this provision, EPA
estimates that about 50 sites now sampling less frequently will be
required to change to daily sampling.
As proposed, minimum monitoring requirements for carbon monoxide
(CO), sulfur dioxide (SO2), and nitrogen dioxide
(NO2) are eliminated in this final rule. Minimum
requirements for lead (Pb) monitoring stations and Photochemical
Assessment Monitoring Stations (PAMS) are reduced to those that were
proposed. For all five criteria pollutants, however, existing
monitoring sites (except those already designated as special purpose
monitors) cannot be discontinued without EPA Administrator (for PAMS or
NCore stations) or Regional Administrator (for all other types of
monitoring) approval. Regional Administrator approval is also required
for discontinuation of O3, PM2.5, and
PM10 sites even if they are in excess of minimum network
design requirements. While the rule requires EPA approval, such
approvals should be facilitated where appropriate by rule provisions
which clearly establish certain criteria under which discontinuation
will be approved. These criteria are the same as those proposed with
four minor changes explained in detail in section V.B.5, System
Modifications. These criteria are not exclusive, and monitors not
meeting any of the listed criteria may still be approved for
discontinuation on a case-by-case basis if discontinuation does not
compromise data collection needed for implementation of a NAAQS.
Specific monitoring for these pollutants may currently be required in
individual SIPs; this monitoring rule does not affect any SIP
requirements for such specific monitoring.
Appendix A to this final rule includes most of the proposed
revisions to the quality system for ambient air monitoring. In
particular, the proposed requirement for States to ensure a program of
adequate and independent audits of their monitoring stations is
included in this final rule. One way, but not the only way, a State can
satisfy this requirement is to agree that EPA will conduct these audits
using funds that otherwise would have been awarded to the State as part
of its annual air quality management grant. A small number of changes
to the proposed quality system requirements reflect public comments on
details of the proposed revisions. Also, because the objective of
PM10-2.5 monitoring is to better understand
PM10-2.5 air quality and to support health effects studies,
rather than to provide data for use in nonattainment designations, and
because there consequently will be a much smaller network of required
PM10-2.5 monitors than proposed, the quality system for
PM10-2.5 in this final rule differs from the proposed system
in that it aims to quantify data quality at the national level of
aggregation rather than at the level of individual monitoring
organizations as had been proposed. Another change from the proposal is
that a provision has been added allowing the EPA Regional Administrator
to waive the usual quality system requirements for special purpose
monitors when those requirements are logistically infeasible due to
unusual site conditions and are not essential to the monitoring
objectives.
The EPA is finalizing the proposed provisions regarding when data
from special purpose monitors (SPMs) can be compared to a NAAQS, with
minor clarifications. In summary, the final rule provides that if an
ozone or PM2.5 SPM operates for only two years or less, EPA
will not use data from that monitor to make attainment/nonattainment
determinations. This limitation is inherent in the form of these NAAQS,
which require three years of data for a determination to be made. For
the other NAAQS pollutants, as a policy matter, EPA will not use only
two years of data from a SPM to voluntarily redesignate an area to
nonattainment. This limitation is possible because as established in
Section 107(d)(1) of the Act, the only time EPA is obligated to
redesignate areas as attainment or nonattainment is after it
promulgates or revises a NAAQS. Under an existing standard, voluntary
redesignations are at the Administrator's discretion: EPA has no legal
obligation to redesignate an area even if a monitor should register a
violation of that standard (see CAA Section 107(d)(3)). In particular,
in the case of PM10, EPA stated in section VII.B of the
preamble to the NAAQS rule (printed in today's Federal Register) that
because EPA is retaining the current 24-hour PM10 standards,
new nonattainment designations for PM10 will not be required
under the provisions of the Clean Air Act. The same is true for CO,
NO2, SO2, and Pb. However, all valid data from a
SPM will be considered in determining if a previously designated
nonattainment area has subsequently attained the NAAQS. See also
section V.B.8 below.
This final rule advances, to May 1, the date each year by which
monitoring organizations must certify that their submitted data is
accurate to the best of their knowledge. However, this requirement will
take effect one year later than proposed, in 2010 for data collected in
2009.
This final rule retains the current requirement for an annual
monitoring plan and finalizes most of the new
[[Page 61241]]
substantive and procedural requirements that were proposed for these
plans. One change is that some required new elements proposed for the
annual plan have instead been shifted to the 5-year network assessment,
to reduce the annual plan preparation burden and to allow these
elements to be prepared more carefully. The first 5-year network
assessment has been postponed by one year, to July 1, 2010.
The proposed requirements regarding probe heights for
PM10-2.5 monitors, increased O3 monitor distance
from roadways (for newly established O3 stations), data
elements to be reported, and PM filter retention are included in this
final rule.
This final rule also removes and reserves the pre-existing appendix
B, Quality Assurance Requirements for Prevention of Significant
Deterioration (PSD) Air Monitoring, and appendix F, Annual SLAMS Air
Quality Information, of 40 CFR part 58 because they are no longer
needed.
C. Significant Dates for States, Local Governments, Tribes, and Other
Stakeholders
Only State governments, and those local governments that have been
assigned responsibility for ambient air monitoring by their States, are
subject to the mandatory requirements of 40 CFR part 58.\3\ The
following summary of applicable requirements is presented in
chronological order, as an aid for States in planning their activities
to comply with the rule. States are required to comply with pre-
existing requirements in 40 CFR part 58, until the compliance date for
each new requirement is reached.
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\3\ Throughout this preamble, ``States'' is meant to also refer
to local governments that have been assigned responsibility for
ambient air monitoring within their respective jurisdiction by their
States. This preamble also uses ``monitoring organization'' to refer
to States, local agencies, and/or Tribes conducting monitoring under
or guided by the provisions of 40 CFR part 58. This final rule
applies the same requirements to the District of Columbia, Puerto
Rico, and the Virgin Islands as apply to the 50 States. Other U.S.
territories are not subject to this final rule.
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The following provisions in 40 CFR part 53 and part 58 are
effective on December 18, 2006:
The criteria and process for EPA Administrator approval of
FRMs, FEMs, and ARMs or where applicable Regional Administrator
approval of ARMs. Manufacturers of continuous PM2.5 and
PM10-2.5 instruments may apply for designation of their
instruments as FRMs or FEMs starting today. The EPA is eager to receive
such applications as soon as manufacturers can collect and analyze the
necessary supporting data. State, local, and Tribal monitoring agencies
may seek approval of their PM2.5 continuous monitor as ARMs
beginning today, either independently or in cooperation with instrument
manufactures.
The revised quality system requirements, except that full
quality assurance practices, if not waived, are not required until
January 1, 2009 for SPMs which use FRM, FEM, or ARM monitors.
The new minimum requirements (or absence of minimum
requirements) for the number of monitors for specific NAAQS pollutants
and for PAMS stations, if the new minimum allows a State to discontinue
a previously required monitor. See below for the compliance date of the
new minimum requirements in situations in which the final requirement
is greater than the currently operating network.
The criteria for EPA Regional Administrator approval for
removal of monitors that are in excess of minimum required, if a State
seeks such removal.
The criteria for use of data from SPMs in determinations
of attainment/nonattainment.
The elimination of the requirement for reporting of
certain PM2.5 monitor operating parameters.
The revised requirement for separation between roadways
and O3 monitors, for new O3 monitors whose
placement has not already been approved as of December 18, 2006.
The new specification for probe heights for
PM10-2.5 monitors.
The new requirement to archive all PM10c and
PM10-2.5 filters for 1 year begins with filters collected on
or after January 1, 2007. However, EPA expects few if any monitoring
agencies to be operating PM10c or PM10-2.5
filters this early, so most will be affected later.\4\
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\4\ As explained in section IV.B of this preamble, the term
``PM10c'' refers to a PM10 Federal reference
method (FRM) that is designated as a PM10c FRM under the
final NAAQS rule appearing elsewhere in today's Federal Register. In
essence, it would be a PM2.5 FRM with the inertial
fractionator used to separate out particles larger than 2.5 microns
removed so that all PM10 is collected. Unlike other
PM10 instruments, a PM10c instrument must
control flow to a specified flow rate of 16.67 liters/minute at
local conditions of temperature and pressure. A PM10-2.5
FRM consists of a PM2.5 FRM and a PM10c FRM of
the same model. See also 71 FR 2720.
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The requirement to submit mass data on blank PM2.5
filters begins on January 1, 2007.
The required date to begin daily PM2.5 sampling at
certain PM2.5 monitoring sites is January 1, 2007. The EPA
believes this will affect about 50 PM2.5 monitoring sites.
The EPA will notify the affected States directly.
This final rule does not change the schedule for reporting ambient
air quality data to the Administrator, via the Air Quality System
(AQS). However the rule now explicitly requires that associated quality
assurance data be submitted along with ambient concentration data. The
first submission affected will be the one due on June 30, 2007 for data
collected in January through March of 2007.
As presently is the case, States must submit an annual network plan
by July 1 of each year. The next plan is due July 1, 2007.
States whose PM2.5, PM10, or O3
networks do not meet the revised requirements of this final rule
regarding the number of monitors in a given MSA or CSA are required to
submit a plan for adding the necessary additional monitors by July 1,
2007 and to begin operating the new monitors by January 1, 2008. The
EPA believes that this will only affect O3 and
PM2.5 monitoring in fewer than ten locations each. The EPA
will notify these States directly.
A plan for the implementation of the required NCore multipollutant
monitoring stations, including site selection, is due by July 1, 2009.
States must implement the required NCore multipollutant stations by
January 1, 2011, including PM10-2.5 monitoring.
States will be required to submit earlier certification letters
regarding the completeness and accuracy of the ambient concentration
and quality assurance data they have submitted to the Air Quality
System (AQS) operated by EPA, starting May 1, 2010 for data collected
during 2009. Until then, States are required to submit these letters by
July 1 of each year.
Network assessments are required from States every 5 years starting
July 1, 2010.
Under the Tribal Authority Rule (TAR) (40 CFR part 49), which
implements section 301(d) of the CAA, Tribes may elect to be treated in
the same manner as a State in implementing sections of the CAA.
However, EPA determined in the TAR that it was inappropriate to treat
Tribes in a manner similar to a State with regard to specific plan
submittal and implementation deadlines for NAAQS-related requirements,
including, but not limited to, such deadlines in CAA sections
110(a)(1), 172(a)(2), 182, 187, and 191. See 40 CFR 49.4(a). For
example, an Indian Tribe may choose, but is not required, to submit
implementation plans for NAAQS-related requirements, nor is any Tribe
required to monitor ambient air. If a Tribe elects to do an
implementation plan, the plan can contain program elements to address
specific air quality problems in a partial program. The EPA
[[Page 61242]]
will work with the Tribe to develop an appropriate schedule for making
any appropriate monitoring system changes which meet the needs of each
Tribe.
Indian Tribes have the same rights and responsibilities as States
under the CAA to implement elements of air quality programs as they
deem necessary. Tribes can choose to engage in ambient air monitoring
activities. In many cases, Indian Tribes will be required by EPA
regions to institute quality assurance programs that comply with 40 CFR
part 58 appendix A, utilize FRM, FEM, or ARM monitors when comparing
their data to the NAAQS, and to insure that the data collected is
representative of their respective airsheds. For FRM, FEM, or ARM
monitors used for NAAQS attainment or nonattainment determinations,
quality assurance requirements of 40 CFR part 58 must be followed and
would be viewed by EPA as an indivisible element of a regulatory air
quality monitoring program.
D. Implementation of the Revised Monitoring Requirements
After promulgation, EPA will assist States in implementing the
amended requirements using several mechanisms. The EPA will work with
each State to develop approvable monitoring plans for its new NCore
multipollutant monitoring stations, including PM10-2.5
monitoring. For example, EPA will negotiate the selection of required
new monitoring sites (or new capabilities at existing sites) and their
schedules for start up as well as plans to discontinue sites that are
no longer needed. The EPA will negotiate with each State its annual
grant for air quality management activities, including ambient
monitoring work. Once States have established a new monitoring
infrastructure to meet the new requirements, EPA will review State
monitoring activities, submitted data, and plans for further changes on
an annual basis.
The EPA's support for and participation in enhancing the national
ambient air monitoring system to serve current and future air quality
management and research needs will extend beyond ensuring that States
meet the minimum requirements of this final monitoring rule. The EPA
will work with each State or local air monitoring agency to determine
what affordable monitoring activities above minimum requirements would
best meet the diverse needs of the individual air quality management
program as well as the needs of other data users. The EPA may also work
with the States, and possibly with some Tribes, to establish and
operate PM10-2.5 speciation sites inaddition to those
required by this final rule. The EPA also plans to work with the
States, and possibly with some Tribes, to establish and operate sites
that will measure only PM10-2.5 concentrations in rural and
less urbanized locations, in addition to the PM10-2.5
monitors required at NCore sites.
An important element of implementing the new requirements will be
EPA's role in encouraging the development and application of FEMs, and
the development of a sampler or samplers that can provide a direct
measurement of PM10-2.5 for collection of filters used in
chemical speciation and for continuous methods that measure both
PM2.5 and PM10-2.5. The EPA has determined that
continuous monitoring of PM2.5 has many advantages over the
filter-based FRM. This final rule makes it more practical for
manufacturers and users of continuous PM2.5 instruments to
obtain designation for them as FEMs or ARMs. To ensure objectivity and
a sound scientific basis for decisions, EPA's Office of Research and
Development will review applications for FEM and ARM designations based
on the criteria in this final rule and will recommend approval or
disapproval to the Administrator. For agencies seeking use of an ARM
already approved in another monitoring network, the applicable Regional
Office will conduct a review, most often as part of the EPA approval of
an annual monitoring plan, based on the criteria in this final
monitoring rule.
The EPA will also provide technical guidance documents and training
opportunities for State, local, and Tribal monitoring staff to help
them select, operate, and use the data from new types of monitoring
equipment. The EPA has already distributed a technical assistance
document on the precursor gas monitors \5\ that will be part of the
NCore multipollutant sites and EPA has conducted multiple training
workshops on these monitors. Additional guidance will be developed and
provided on some other types of monitors with which many State
monitoring staff are currently unfamiliar, and on network design, site
selection, discontinuation of sites, quality assurance, network
assessment, and other topics. While Tribes are not subject to the
monitoring requirements of this final rule, these technical resources
will also be available to them directly from EPA and via grantees, such
as the Institute for Tribal Environmental Professionals and the Tribal
Air Monitoring Support Center.
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\5\ Technical Assistance Document (TAD) for Precursor Gas
Measurments in the NCore Multipollutant Monitoring Network. Version
4. U.S. Environmental Protection Agency. EPA-454/R-05-003. September
2005. Available at: http://www.epa.gov/ttn/amtic/pretecdoc.html.
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The EPA will also continue to support the National Park Service's
operation of the IMPROVE monitoring network, which provides important
data for implementing both regional haze and PM2.5
attainment programs.\6\ The number of sites in the IMPROVE program may
vary, depending on EPA's enacted budget and the data needs of the
regional haze and PM2.5 attainment programs.
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\6\ Additional information on EPA/National Park Service IMPROVE
(Interagency Monitoring of Protected Visual Environments) Visibility
Program is available at: http://www.epa.gov/ttn/amtic/visdata.html.
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The EPA will also continue to operate the Clean Air Status and
Trends Network (CASTNET), which monitors for O3, PM, and
chemical components of PM in rural areas across the nation.\7\ EPA is
in the process of revising CASTNET to upgrade its monitoring
capabilities to allow it to provide even more useful data to multiple
data users. The EPA expects that about 20 CASTNET sites will have new
capabilities similar to some of the capabilities required at NCore
multipollutant sites.
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\7\ Additional information on CASTNET is available at: http://www.epa.gov/castnet/.
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This final rule includes a requirement that States must ensure a
program of adequate and independent audits of their monitoring
stations. One way, but not the only way, a State can satisfy this
requirement is to agree that EPA will conduct these audits using funds
that otherwise would have been awarded to the State as part of its
annual air quality management grant. In anticipation of the possible
inclusion of this requirement in this final rule, EPA has been working
with monitoring organizations to determine which of these organizations
prefer this approach. The EPA expects that, for 2007, nearly all
monitoring organizations will request that EPA conduct these audits.
For those that chose another acceptable approach, EPA will conduct
limited cross-checks of equipment, calibration standards, auditor
preparation, and audit procedures to ensure that their audit programs
are adequate.
The EPA recognizes that characterizing and managing some air
quality problems requires ambient concentration and deposition data
that cannot be provided by the types of monitoring required by the
monitoring activities addressed in today's final rule. These problems
include near-roadway exposures to emissions from motor
[[Page 61243]]
vehicles and mercury deposition. The EPA is actively researching these
issues and developing concepts for monitoring programs to address them,
but these issues are outside the scope of this final rule.
The Air Quality System (AQS) is the data system EPA uses to receive
ambient air monitoring data from State, local, Tribal, and other types
of monitoring organizations and to make those data available to all
interested users. AQS is based on a particular data structure and uses
particular data input formats including data elements and defined
values for categorical data. The existing AQS data structure and input
formats are for the most part consistent with a number of changes made
in this final rule to pre-existing terminology and requirements, but
some changes will be needed in AQS to re-establish full consistency
with requirements in the monitoring rule. The changes to AQS will
likely, in turn, require some modifications to data preparation tools
and practices at monitoring agencies. The EPA will prepare and
implement a plan for making these changes, and will advise AQS users of
the ramifications while doing so. Generally, the compliance deadlines
in the rule are such that monitoring agencies are not required to
immediately comply with any changes in rule provisions that would
affect data transfer formats and procedures. Monitoring agencies, for
the present, should continue to follow pre-existing AQS formats and
procedures until notified.
E. Federal Funding for Ambient Air Monitoring
EPA has historically funded part of the cost to State, local, and
Tribal governments of installation and operation of monitors to meet
Federal monitoring requirements. Sections 105 and 103 of the CAA allow
EPA to provide grant funding for programs for preventing and
controlling air pollution and for some research and development efforts
respectively. Eligible entities must apply for section 103 grants.
Eligible entities must provide nonfederal matching funds for section
105 grants. The EPA's enacted budget specifies overall how much State
and Tribal Air Grant (STAG) funding is available for these grants.
In recent years, EPA has received special authority through
appropriations acts to use section 103 grant funding for establishing
and operating PM2.5-related monitoring stations. Funding for
other types of monitoring has been included in the grants awarded under
section 105. Grants to Tribes for air quality management work,
including ambient monitoring, have been awarded under section 103 with
the overall amount for these funds established by the enacted budget.
During the public comment period for this rulemaking EPA received a
large number of comments addressing funding issues. Most of these
comments expressed opposition to the Administration's proposed EPA
budget for fiscal year 2007, which included a proposal to provide
PM2.5 monitoring support through section 105 grant funding,
as is done for all other criteria pollutants. (As of today, the
Congress has not enacted a 2007 budget for EPA.) Commenters stated that
if funding for monitoring were reduced as proposed, State and local
agencies would have less flexibility than desired in designing and
operating their monitoring programs, and that the proposed requirements
for new PM10-2.5 and NCore networks and for adequate and
independent audits of monitoring stations would be burdensome. Some
commenters requested that the proposed new requirements not be included
in this final rule for this reason.
The EPA understands these concerns. However, the CAA requirements
from which this final rule derives \8\ are not contingent on EPA
providing funding to States to assist in meeting those requirements.
Accordingly, the comments regarding funding are not directly relevant
to the content of this final rule. Nevertheless, EPA recognizes that
resources always have been and will remain a practical consideration
for establishing and operating monitoring programs. The EPA will
continue to work with States in this regard, in particular as EPA
determines how to allocate enacted funding among States and among types
of monitoring so as to achieve the best possible environmental
outcomes. Several provisions of this final rule reduce minimum
requirements, which will provide flexibility for States to reduce some
of their pre-existing costs.
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\8\ Section 103(c)(2) of the Clean Air Act [42 U.S.C.A. 7403(c)]
provides that the Administrator shall conduct a program for sampling
air pollution that includes the establishment of a national network
to monitor air quality and to ensure the comparability of air
quality data collected in different states. Section 110(a)(2)(B) [42
U.S.C.A 7410(a)] provides that each State implementation plan shall
provide for establishment and operation of appropriate devices,
methods, systems, and procedures necessary to monitor, compile, and
analyze data on ambient air quality and upon request make such data
available to the Administrator. Section 182(c)(1) [42 U.S.C.A.
7511a(c)(1)] states that the Administrator will promulgate rules for
enhanced monitoring for ozone, oxides of nitrogen, and volatile
organic compounds in serious ozone areas.
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Several commenters stated that EPA should not use STAG funds for
the improvement or operation of Federal monitoring networks such as
CASTNET. The EPA does not intend to use STAG funds from fiscal year
2007 or beyond in this way.
IV. Discussion of Regulatory Revisions and Major Comments on Proposed
Amendments to 40 CFR Part 53
A. Overview of Part 53 Regulatory Requirements
Various appendices to 40 CFR part 50 define certain ambient air
monitoring methods as Federal reference methods which may be used to
determine attainment of the National Ambient Air Quality Standards
(NAAQS), and which form the benchmark for determining equivalency of
other methods which may also be used to determine attainment. Under 40
CFR part 53, EPA designates specific commercial instruments or other
versions of methods as Federal reference methods (FRMs). To be so
designated, a particular FRM must be shown, according to the procedures
and requirements of part 53, to meet all specifications of both the
applicable appendix of part 50 as well as applicable specifications and
requirements of part 53.
To foster development of improved alternative air monitoring
methods, EPA also designates--as Federal equivalent methods (FEMs)--
alternative methods that are shown to have measurement performance
comparable to the corresponding FRM. Part 53 contains explicit
performance tests, performance standards, and other requirements for
designation of both FRMs and FEMs for each of the criteria pollutants.
In addition, States' air surveillance monitoring networks are required,
under 40 CFR part 58, appendix C, to use only EPA-designated FRMs,
FEMs, or ARMs at SLAMS sites. A list of all methods that EPA has
designated as either FRMs or FEMs for all criteria pollutants is
available at http://www.epa.gov/ttn/amtic/criteria.html.
Elsewhere in today's Federal Register, EPA is promulgating a new
Federal reference method for measurement of mass concentrations of
thoracic coarse particles (PM10-2.5) in the atmosphere, to
be codified as appendix O to 40 CFR part 50. Although, as explained
earlier, EPA is not at this time adopting any NAAQS for
PM10-2.5, EPA believes an FRM for PM10-2.5 is
still highly desirable to aid in a variety of needed
[[Page 61244]]
research studies.\9\ This new FRM is defined as the standard of
reference for measurement of PM10-2.5 concentrations in
ambient air. It will be an acceptable and readily available
PM10-2.5 measurement method for new NCore multipollutant
monitoring sites to be located at approximately 75 urban and rural
locations. Availability of an approved FRM for PM10-2.5 will
also help provide consistency among PM10-2.5 measurements
used in future health studies of the adverse health effects associated
with exposure to thoracic coarse particles. Lastly, the
PM10-2.5 reference method will provide the basis for
development of speciation samplers capable of providing an improved
understanding of the compositions of different ambient mixes of
thoracic coarse particles, so that this composition can be related to
both health effects and to particle sources. Associated with this new
reference method, EPA is also establishing related amendments to 40 CFR
part 53 to extend the designation provisions of FRMs and FEMs to
methods for PM10-2.5. These amendments set forth explicit
tests, performance standards, and other requirements for designation of
specific commercial samplers, sampler configurations, or analyzers as
either FRMs or FEMs for PM10-2.5, as appropriate.
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\9\ Henderson, R. Clean Air Scientific Advisory Committee
(CASAC) Review of the EPA Staff Recommendations Concerning a
Potential Thoracic Coarse PM Standard in the Review of the National
Ambient Air Quality Standards for Particulate Matter: Policy
Assessment of Scientific and Technical Information (Final PM OAQPS
Staff Paper, EPA-452/R-05-005). September 15, 2005. http://www.epa.gov/sab/panels/casacpmpanel.html.
Henderson, R. Letter from Dr. Rogene Henderson, Chair, Clean Air
Scientific Advisory Committee to the Honorable Stephen L. Johnson,
Administrator, U.S. EPA. Clean Air Scientific Advisory Committee
Recommendations Concerning the Proposed National Ambient Air Quality
Standards for Particulate Matter. March 21, 2006. http://www.epa.gov/sab/pdf/casac-ltr-06-002.pdf.
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As noted in section VI.A of the preamble to the NAAQS revisions
published elsewhere in this Federal Register, EPA recognizes that the
FRM, while providing a good standard of performance for comparison to
other methods, is not itself optimal for routine use in
PM10-2.5 monitoring networks. Alternative methods are needed
that provide a more direct measurement of ambient PM10-2.5
concentrations. Methods are also needed that collect samples of
PM10-2.5 that are more physically separated for analysis of
chemical species. Also, automated, continuous-type methods provide many
operational advantages to ease monitoring burdens, reduce on-site
service requirements, and eliminate off-site sample filter support
services, as well as to provide measurement resolution of 1 hour or
less and near real-time reporting of monitoring data. Therefore, EPA is
interested in encouraging the development of alternative monitoring
methods for PM10-2.5 by focusing on the explicit test and
qualification requirements necessary for designation of such types of
methods as FEMs for PM10-2.5. In fact, EPA anticipates that
alternative FEMs will eventually provide most of the
PM10-2.5 monitoring data obtained in the States' monitoring
networks.
Further, EPA recognizes that the potential benefits of automated/
continuous monitoring methods apply as well to FEMs for
PM2.5. Accordingly, as proposed, EPA is also establishing
new requirements in part 53 for designation of continuous FEMs for
PM2.5. See 71 FR 2721. The PM2.5 and
PM10-2.5 FEM provisions parallel each other in many respects
so inclusion now is both appropriate and conforming.
The new requirements for approval of automated/continuous FEMs can
accommodate a wide range of potential PM10-2.5 or
PM2.5 continuous measurement technologies. Ambient air
testing of a candidate technology at diverse monitoring sites is
required in order to demonstrate that the level of comparability to
collocated Federal reference method measurements is adequate to meet
established data quality objectives (DQOs).
This final rule also modifies somewhat certain existing
requirements for designation of alternative, non-continuous methods for
PM2.5. As explained in section IV.B of this preamble, the
modified requirements will be fully consistent with the more advanced
new requirements for both continuous and non-continuous FEMs for
PM10-2.5.
B. Requirements for Candidate Reference Methods for PM10-2.5
No comments were received related specifically to the
PM10-2.5 FRM designation requirements. These provisions are
adopted as proposed. Because of the nearly complete similarity between
the specifications for the new PM10-2.5 reference method and
for the existing PM2.5 reference method, the designation
requirements for PM10-2.5 reference methods are essentially
the same as those for PM2.5 reference methods. As set forth
in the new appendix O to 40 CFR part 50, the PM10-2.5
reference method specifies a pair of samplers consisting of a
conventional PM2.5 sampler and a special PM10
sampler. The PM2.5 sampler must meet all requirements for a
PM2.5 reference method in 40 CFR part 50, appendix L, as
well as additional requirements in part 53. However, the
PM10 sampler required by the method is not a conventional
PM10 sampler as described in 40 CFR part 50, appendix J;
rather, it is a sampler specified to be identical to the
PM2.5 sampler of the pair, except that the PM2.5
particle size separator is removed. This special PM10
sampler is identified as a ``PM10c'' sampler to
differentiate it from conventional PM10 samplers that meet
the less exacting requirements of 40 CFR part 50, appendix J. In view
of the similarity of the PM10-2.5 FRM requirements to those
of the PM2.5 FRM, the new requirements will allow a
PM10-2.5 sampler pair consisting of samplers that have
already been shown to meet the PM2.5 FRM requirements
(except for the PM2.5 particle size separator in the case of
the PM10c sampler) to be designated as a PM10-2.5
reference method without further testing.
C. Requirements for Candidate Equivalent Methods for PM2.5
and PM10-2.5
As pointed out in the preamble to the proposed rule (71 FR 2721),
EPA believes very strongly that provisions to allow designation of
Federal equivalent methods provide an important incentive to encourage
the commercial development of innovative new and advantageous
alternative methods for monitoring air pollutants. However, it is also
important to show conclusively that any new candidate method will
produce measurements comparable to those of the FRM and will have
performance characteristics that are adequate to meet DQOs. At the same
time, the testing that is necessary to show comparable and adequate
performance must not be so burdensome that it undermines incentives for
new method development.
Because of the complex nature of particulate matter, it is also
complex to test the performance of PM monitoring methods. For methods
for PM2.5, EPA defined three classes of candidate FEMs
(Classes I, II, and III) based on the extent to which the method
differs from the FRM, so that the nature and extent of the performance
and comparability testing necessary can be more closely matched to the
nature of the candidate method. See 40 CFR 53.3(a)(2)-(4). In this
final rule, as proposed, EPA is extending these same class definitions
and tiered testing requirements to apply to PM10-2.5
candidate FEMs as well.
Class I methods are limited to minor deviations from the FRM; Class
II covers
[[Page 61245]]
integrated-sample, filter-based, gravimetric methods deviating more
significantly from the FRM; and Class III methods (originally) included
all other methods not categorized as Class I or II. The three classes
are described in more detail in the proposal preamble (71 FR 2721). As
proposed, the definition of Class III FEMs is narrowed to include only
continuous or semi-continuous analyzer methods having 1-hour or less
measurement resolution, which are the Class III methods that by far
hold the most potential for monitoring applications and FEM
designation. The EPA has thus avoided the restrictions and complexity
that would be necessary to accommodate the wide variety of other types
of non-Class I or II methods that are unlikely to be economically and
commercially practical. Also, the continuous operational nature of such
Class III methods gives rise to a statistical advantage that allows
more tolerant limits of adequate comparability, relative to a method
that is not operated continuously, to achieve a similar limit of
uncertainty in the monitoring data.
Class III continuous methods appear to offer many potential
benefits for use in routine field monitoring networks. These automated
analyzers eliminate most, if not all, of the pre- and post-weighing of
sample filters, require less frequent on-site service, may be less
costly to operate, and offer near real-time, electronic reporting of
hourly (or less) mass concentration measurements (similar to data
reporting that is common for gaseous pollutant monitors). The EPA is
accordingly adopting the proposed Class III FEM provisions for
PM10-2.5 and PM2.5 in today's rule, with some
changes in response to comments.
Continuous methods, by nature, tend to have somewhat different
performance characteristics from those of the corresponding filter-
based FRMs, so the comparability and performance testing requirements
must be adequately comprehensive and discriminating without being
excessively burdensome. The Class III FEM requirements being
promulgated today are based predominantly on demonstrating an adequate
degree of comparability between candidate method measurements and
concurrent, collocated Federal reference method measurements under a
representative variety of site conditions. Many issues and much
technical input were carefully considered during the development of the
requirements, including peer review by the Ambient Air Monitoring and
Methods Subcommittee of the Clean Air Scientific Advisory Committee.
The salient Class III FEM requirements were summarized in the proposal
preamble (71 FR 2722-2724). Not unexpectedly, a considerable number of
comments were received in connection with the specifics of the proposed
Class II and Class III requirements. The more significant of these
comments are addressed below, after a summary of the proposal regarding
requirements for Class II and Class III methods. Remaining comments are
addressed in the Response to Comments document.
Class II candidate FEMs, although not offering the operational
advantages of continuous Class III methods, are nevertheless important
as well. Class II methods encompass the dichotomous and virtual
impactor types of methods that can provide a more direct, gravimetric,
filter-based measurement of PM10-2.5 than available with the
FRM. These methods are also most likely to fulfill the substantial need
for collecting PM10-2.5 samples that are physically
separated from other particle sizes, or nearly so, for chemical species
analysis. New requirements for Class II FEMs for PM10-2.5
are being established in this final rule, and some of the previously
established requirements for Class II FEMs for PM2.5 are
being changed somewhat to make them more consistent with the
corresponding new requirements for PM10-2.5 Class II FEMs
and to incorporate some minor technical improvements.
The proposed Class II FEM requirements, as outlined in the proposal
preamble (71 FR 2721-2725), were based on daily sampling; therefore,
Class II equivalent methods used for determining compliance with the
PM2.5 NAAQS would generally have been restricted to daily
sampling. However, in response to concerns about method performance in
relatively clean areas, EPA has strengthened the additive bias
(intercept) requirement. With this tighter performance criteria and
considering that Class II methods are filter-based samplers, a minimum
of a one-in-three day sample frequency will be appropriate to meet the
network data quality objectives. Class II methods are also expected to
be used for collecting samples used in chemical species analysis, which
would not require daily operation. The character of the test sites
specified for Classes II and III tests for both PM2.5 and
PM10-2.5 are similar, so concurrent testing for
PM2.5 and PM10-2.5 methods of both classes can be
carried out, substantially reducing the testing burden for candidate
FEMs that measure both PM2.5 and PM10-2.5 or for
testing multiple candidate methods simultaneously.
Of particular note to instrument manufacturers, this final rule
allows applications for Class II candidate FEMs for both
PM10-2.5 and PM2.5 to optionally substitute the
more extensive Class III comparability field tests in subpart C for
some or all of the rather extensive and arduous laboratory wind tunnel
tests, loading test, and volatility test of subpart F to which a Class
II candidate FEM sampler may otherwise be subject. Such a substitution
of test results may be particularly important when the special
facilities necessary for the wind tunnel tests or other tests are not
available. Concurrent testing of multiple methods under the Class III
requirements may also help to reduce overall testing costs.
In regard to the proposed testing requirements for Class III
(continuous) FEMs for PM2.5 and PM10-2.5, EPA
specifically solicited comments related to the adequacy of the number
and location of the test sites required for the field tests to
determine comparability of a candidate method to the respective FRM.
See 71 FR 2722. By definition, a designated FEM is generally qualified
for use at any monitoring site in the U.S. (with the possible exception
of some areas with extreme conditions), so the test requirements for
comparability need to represent a wide variety of possible site
conditions. The EPA proposed that candidate methods be tested within
three general geographical areas: (1) The Los Angeles area in winter
and summer seasons, (2) eastern U.S. in winter and summer, and (3)
western U.S. in winter only (for a total of five 30-day test
campaigns). Each proposed test site area was selected for representing
particular and diverse typical site conditions.
In response to several comments addressing this issue, a fourth
test site--in the U.S. Midwest, with tests required in the winter
season only--has been added to the requirements to further increase the
geographical diversity. However, the requirement for a winter test
campaign in the eastern U.S. has been withdrawn while the requirement
for a summer test campaign in the eastern U.S. has been retained, so
the total number of required test campaigns (five) is unchanged.
Comparability testing of a candidate method is costly, rendering it
impractical to test a candidate method under all possible combinations
of site and seasonal conditions that might be encountered in national
PM monitoring networks. The EPA considers the specified complement of
five test campaigns in the four specified geographical areas and two
seasons to be reasonable to conduct and adequately representative of
the diversity of site and seasonal PM
[[Page 61246]]
monitoring conditions across the U.S. As noted above, the two test site
areas specified for testing candidate Class II FEMs are compatible with
the test sites for candidate Class III methods, which will
significantly reduce testing costs by allowing Class II and III
candidate methods to be tested simultaneously at the same test site.
Also, the test sites have been relabeled for ease of referencing east
and west sites.
Some commenters expressed concern that the Class III comparability
test standards might be inadequate because a candidate method that had
an unacceptable seasonal bias (such as has been noted for some
continuous methods) could be found acceptable, because in pooling test
data from summer and winter seasons the biases would compensate. The
EPA finds that the associated minimum correlation requirement of the
regression test should adequately avoid that situation. Further, in the
revised test requirements, summer and winter tests at the same site,
where the data are pooled, are required at only one of the four
required tests sites.
Another issue concerning the proposed testing requirements for
Class III (continuous), as well as Class II candidate equivalent
methods for PM2.5 and PM10-2.5, was the specific
acceptance criteria for the regression analysis statistics--
particularly the additive bias (intercept) parameter--of the comparison
between collocated measurements obtained with the candidate and FRM
methods. As proposed, the upper and lower limits for the regression
intercept were specified as functions of the corresponding slope, with
the acceptable combinations of slope and intercept represented by the
area inside a trapezoid or a hexagon shape plotted on a slope-intercept
coordinate system (Figures C-2 and C-3 in proposed revised subpart C of
part 53 at 71 FR 2768-2769). These acceptance limits were based on
statistical considerations related to the uncertainty allowable in
making correct NAAQS attainment decisions for PM2.5 (or
similar comparisons of PM10-2.5 concentrations to non-
regulatory benchmarks). Several commenters were concerned that the
range of acceptable intercepts proposed for Class II and III FEMs,
although appropriate for DQOs related to attainment (or similar)
decisions, may allow excessive measurement bias for FEMs used for other
PM monitoring applications--especially those applications that require
measurements of concentrations well below the level of the NAAQS.
In response to these comments and in deference to potential use of
FEMs for a variety of applications, EPA has somewhat strengthened the
range of allowable intercepts for those candidate FEMs. For Class III
FEMs, new fixed limits of 2.0 [mu]g/m3 for
PM2.5 methods and 7.0 [mu]g/m3 for
PM10-2.5 methods have been added. For Class II FEMs for
PM10-2.5, the fixed intercept limit has been reduced from
7.0 to 3.5 [mu]g/m3. (The intercept
requirements proposed for candidate Class II PM2.5 methods
were re-examined and found to be appropriate as proposed.) The more
restrictive intercept limits will reduce the maximum allowable
measurement bias and are represented by smaller hexagonal acceptance
areas, as specified in 40 CFR part 53, subpart C revised Table C-4 and
as illustrated in revised Figures C-2 and C-3 of this final rule.
Nevertheless, EPA wishes to point out that, because of the design
of the equivalent method comparability tests (which require no low-
level test concentrations) and the nature of the regression analysis, a
seemingly high positive or negative intercept resulting from the
regression analysis of the test data is not necessarily indicative or
likely to be characteristic of the actual measurement errors or bias of
the candidate method relative to the FRM at low or very low
concentrations. This situation may be particularly true when the
concentration coefficient of variation (CCV) for the FEM test data (see
40 CFR 53.35(h)) is relatively low, resulting in greater uncertainty in
the predicted additive bias (and in the multiplicative bias (slope) as
well).
Class III FEMs will generally provide 1-hour concentration
measurements (in addition to the required 24-hour measurements), and
EPA asked for comments on whether the FEM provisions should include any
specific requirements for 1-hour precision, and if so, whether a
specific standard of performance should be specified and how it should
affect FEM designation. See 71 FR 2723. Of the few comments received on
this issue, most agreed with EPA that 1-hour precision is an important
descriptor associated with a Class III candidate method and that 1-hour
FEM test data should be submitted in a Class III FEM application so
that the short-term precision can be determined, but no specific
standard should be set for the precision parameter in connection with
the FEM designation qualifications. A few commenters suggested that a
precision performance parameter based on a running average of a few
(e.g., 3 to 5) hours should be established and regulated, however, to
preserve flexibility, EPA believes that precision estimates are better
included in method-specific quality assurance guidance (to be used by
instrument operators as they believe appropriate) rather than as a
formal part of the FEM provisions. Therefore, no changes were made to
the proposed requirement that FEM applicants submit the 1-hour FEM test
data, and there is no designation requirement based on 1-hour precision
or any other particular 1-hour based performance statistic.
The EPA also asked for comments on the adequacy and appropriateness
of the proposed test requirements for Class II FEMs. See 71 FR 2724.
Some commenters suggested that the proposed Class II tests were
inadequate because there was more variation in the PM at different
sites than could be represented in the tests--particularly in regard to
chemical compositions--and suggested that continued FEM designation
should be conditioned on a mandatory periodic reassessment of local-
agency comparisons to FRM measurements. The EPA recognizes that data
produced by all FEMs operated in monitoring networks under 40 CFR part
58 should meet the data quality objectives (DQOs) of 40 CFR part 58,
appendix A, section 2.3.1 on a continuing basis. The operational
requirements of appendix A will help ensure this. Moreover, EPA can
invoke designation cancellation procedures for the method designation
under 40 CFR 53.11 (Cancellation of reference or equivalent method
designation) if EPA observes that DQOs are not being maintained for a
particular designated Class II equivalent method (or for any FEM or
FRM). However, EPA believes that designation cancellation should be
initiated by EPA when necessary, rather than have designations
conditioned on specific periodic reassessments as commenters suggested.
Other commenters suggested that the test sites be approved by both EPA
and the STAPPA/ALAPCO Monitoring Committee, but EPA believes that would
be cumbersome and unnecessary.
D. Other Changes
EPA proposed several other relatively minor changes to various
provisions of subparts A, C, E, and F of part 53. See 71 FR 2724-2725.
Organizational changes in subpart C consolidate the provisions for
various types of methods, making them easier to understand. Other
changes clarify or simplify some existing provisions for
PM10 and PM2.5 Class I and II FEM testing and
implement minor technical improvements to test protocols, with little,
if any, impact on the nature or efficacy of the tests. Minor changes
are made to subparts A, E, and F to incorporate the new
PM10-2.5 provisions and some new definitions,
[[Page 61247]]
make a few administrative adjustments, and incorporate a few minor
technical changes. These changes are described more completely in the
proposal preamble (71 FR 2724), and they are being adopted as proposed,
as no comments were received pertinent to these minor changes.
After considering all comments carefully, EPA determined that no
further changes should be made to the proposed new or revised FRM and
FEM requirements. The EPA is thus adopting the proposed new or revised
requirements and provisions for Federal reference and Federal
equivalent methods for PM2.5 and PM10-2.5,
modified to incorporate the changes described above.
V. Discussion of Regulatory Revisions and Major Comments on Proposed
Amendments to 40 CFR Part 58
A. Overview of Part 58 Regulatory Requirements
Part 58 of 40 CFR, Ambient Air Quality Surveillance, contains
requirements for ambient air monitoring programs operated by States (or
designated local agencies). As proposed, the structure of part 58
remains much the same as the 1997 version. Proposed subparts A through
G, containing 40 CFR 50.1 through 50.61, provide definitions of terms;
require the operation of certain numbers and types of monitors by
certain dates; require the use of certain monitoring methods, quality
system practices, and sampling schedules and frequencies; require
annual plans describing a State's monitoring network and planned
changes to it; provide criteria for EPA approval of planned changes;
require data submission and certification that submitted data is
accurate to the best of the knowledge of responsible State official;
address special rules regarding special purpose monitors; provide rules
for comparing monitoring data to applicable National Ambient Air
Quality Standards (NAAQS); require reporting of the Air Quality Index
(AQI) to the public in some areas; and provide for monitoring directly
by EPA if a State fails to operate required monitors. As proposed, part
58 also includes appendices A, C, D, E, and G which were referenced by
various numbered sections in subparts A through G. These appendices
contain many detailed requirements, as well as considerable explanatory
or background material and non-binding advice. Appendix A addresses
quality system requirements, appendix C addresses monitoring methods
and equipment, appendix D mostly addresses the number of required
monitors and their placement within a metropolitan or other area,
appendix E addresses the details of monitoring station layout, and
appendix G addresses AQI reporting. (Subpart B of the 1997 version was
proposed to be removed. Subpart F was already reserved in the 1997
version. No amendments were proposed to the part 58 requirements for
reporting of the AQI and the associated appendix G.)
To aid in understanding the provisions of the final part 58 and
their relationship to the 1997 and proposed provisions, the following
discussion for the most part follows the order of the final part 58,
addressing each affected numbered section and then the appendices.
B. General Monitoring Requirements
1. Definitions and Terminology
The EPA proposed to discontinue the use of the term ``National air
monitoring stations (NAMS)''. See 71 FR 2720. Previously, this term was
used to designate Federal reference method (FRM) and Federal equivalent
method (FEM) monitors which were operated to meet set requirements for
the number (and, for some pollutants the type of location) of monitors
and which required EPA Administrator approval for changes, as
distinguished from ``State and local air monitoring stations (SLAMS)''
which referred to additional FRM and FEM monitors for which generally
there was no minimum number, for which siting was more at the State's
discretion, and for which changes were approved by the Regional
Administrator.
The EPA proposed a new definition for ``National Core (NCore)''
stations.
The definition of ``State or local air monitoring stations
(SLAMS)'' was proposed to be modified to include NCore, Photochemical
Air Monitoring Systems (PAMS), and all other State or locally operated
stations (such as PM2.5 speciation stations) that have not
been designated as a special purpose monitor or monitoring station
(SPM). This change was proposed for convenience in referencing these
types of monitors together because some provisions in the rule apply to
all of them but not to SPMs. See 71 FR 2720. Previously, ``SLAMS''
referred only to FRM and FEM monitors.
The term, ``Approved regional methods'' (ARMs), proposed at 71 FR
2720, is added to refer to alternative PM2.5 methods that
have been approved by EPA for use specifically within a State, local,
or Tribal air monitoring network for purposes of comparison to the
NAAQS and to meet other monitoring objectives, but which may not have
been approved as FEM for nationwide use.
The EPA proposed to adopt a new term, ``Primary quality assurance
organization'' to clarify the working definition of the term
``Reporting organization'' currently utilized in section 3.0.3. of 40
CFR part 58, appendix A, Quality Assurance Requirements, and to avoid
confusion with the different way ``reporting organization'' has come to
be used in a related but distinct context (final uploading of data to
the Air Quality System). See 71 FR 2778.
The EPA also proposed additional definitions to be consistent with
terminology used in 40 CFR part 50, appendix O, the FRM for
PM10-2.5. See 71 FR 2777. Modifications to the definitions
of key geographical terms were proposed, as needed, to reflect changes
in U.S. Census Bureau usage since the last revision to monitoring
regulations.
The EPA received some questions seeking clarification of the new
term ``Primary quality assurance organization,'' which are addressed in
the Response to Comments document available in the docket. No other
adverse comments were received on these proposed definitions, and this
final rule includes all of them.
2. Annual Monitoring Network Plan and Periodic Network Assessment
The EPA proposed to consolidate current requirements for the SLAMS
air quality surveillance plan and NAMS network description into
elements of the annual monitoring network plan described in 40 CFR
58.10 of the proposed rule. See 71 FR 2725. The annual monitoring
network plan would provide a statement of purpose for each monitor in a
monitoring agency network and provide evidence that siting and
operation of each monitor meet the requirements of appendices A, C, D,
and E of part 58, as applicable. The EPA also proposed the addition of
some required elements to the annual monitoring network plan and
proposed to add a new requirement for a periodic network assessment.
The EPA received comments on a number of specific elements within
the annual monitoring network plan and with regard to the network
assessment requirement. The comments that were the basis for
modifications to the proposed rule are discussed briefly here. Detailed
responses to all comments are provided in the Response to Comments
document available in the docket.
Comments were received on the proposed requirement for a 30-day
[[Page 61248]]
public inspection period before State submittal of a draft annual
monitoring network plan to the Regional Administrator as well as on the
proposed requirement for Regional Administrator approval of annual
monitoring network plans seeking SLAMS network modifications including
new monitoring sites. Some commenters requested clarification regarding
what methods would be considered acceptable for making documents
available for public inspection. Commenters also expressed concern that
the 120 days proposed for Regional Administrator review and approval/
disapproval would result in unnecessary delays.
The EPA notes the general support in the comments for the public
inspection requirement. Commenters also supported the flexibility in
the proposed rule which would allow monitoring agencies to design and
implement appropriate ways of allowing this inspection. The EPA
supports use of monitoring agency Web sites for such postings, along
with other means of providing public notice including hard-copy posting
in libraries and public offices. Although the public inspection
requirement does not specifically require States to obtain and respond
to received comments, such a process is encouraged with the subsequent
transmission of comments to the appropriate EPA Regional Office for
review. Therefore, EPA has modified this final rule from the proposal
to specify that where the State has provided for a public comment
process and provided any comments received to EPA, and the posted plan
has not been substantially altered as a result of the public comments,
the requirement for the Regional Administrator to obtain public comment
by a separate process can be waived. The 120 days allowed for Regional
Administrator review of an annual plan is a feature of the current
monitoring rule, and has been kept in this final rule.
The EPA received many comments on the proposed requirement for the
annual monitoring network plan to contain cost information. See 71 FR
2780. Commenters were concerned that no details were provided regarding
what information would be required and how the information would be
used. The accounting difficulty in calculating such cost information
was also noted along with concerns regarding the administrative burden
of preparing and documenting the cost estimates.
The EPA has considered the proposed requirement for cost
information in the annual monitoring network plan and agrees that
considerable effort would be needed to develop guidance to standardize
the development of financial information and for States to collect and
summarize the information for submittal. Without such standardization,
cost information would be difficult to interpret. In view of these
comments, EPA has deleted this element from the list of required
information to be contained in the annual monitoring network plan.
The EPA proposed a new requirement that the annual monitoring
network plan consider the ability of existing and proposed sites to
support air quality characterization for areas with relatively high
populations of susceptible individuals (e.g., children with asthma),
and, for any sites that are being proposed for discontinuance, the
effect on data users other than the agency itself, such as nearby
States and Tribes or health effects studies. See 71 FR 2780. Several
commenters noted that this requirement would be challenging to
implement and involves knowledge of public health that may not be
readily available to monitoring organizations. In addition, it was
noted that, absent the availability of a centralized information
clearinghouse, it would be difficult for States to be aware of all
possible users of data for health studies or other types of research.
This new element of the annual monitoring network plan highlights
the importance that EPA places on the consideration of sensitive
populations when evaluating the relative value and representativeness
of monitoring sites, particularly for areas where one or more NAAQS may
be approached or exceeded.\10\ The EPA acknowledges the potential
challenge in obtaining information about the distribution of
susceptible individuals in specific geographic areas around existing
and proposed sites, and has purposely defined the requirement as a
``consideration'' to provide significant latitude for monitoring
organizations to determine the complexity and depth of their response.
In recognition of the potential complexity of preparing assessments of
susceptible populations on a sub-county sized spatial scale as
represented by typical monitoring sites, in this final rule EPA has
moved this requirement to become a required element of the 5-year
network assessment rather than the annual monitoring network plan.
---------------------------------------------------------------------------
\10\ See S. Rep. No. 91-1196. 91st Cong. 2d Sess. 10 (1970)
(NAAQS is to be set to protect sensitive, at-risk population
groups).
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With regard to the proposed provision requiring States to consider
the effect on data users of proposed actions to discontinue sites, EPA
notes that States are already required to make their annual network
monitoring plans available for public inspection and that process
provides the basic framework for disseminating information about
anticipated site discontinuations. The EPA recognizes that there are
many potential users of air quality information and that States cannot
be aware of all such users. However, to the extent that information
about site shutdowns can be disseminated more widely, there are
benefits to be gained by protecting key monitors that (for example)
support ongoing health studies or that are the basis for long-term
trend analyses, or otherwise provide information that is used by
stakeholders other than the operating agency. As such, EPA has retained
this provision in this final rule. The EPA will work with States and
health organizations to explore options for tracking the status of key
air quality sites.
The EPA received many comments in response to the proposed
requirement for a network assessment to be completed every 5 years and
to be submitted with the required annual network monitoring plan.
Commenters acknowledged the overall value of a more complete evaluation
of monitoring programs but expressed concern about the resource burden
in meeting the requirement.
Network assessments are a key tool to help ensure that the right
parameters are being measured in the right locations, and that
monitoring resources are used in the most effective and efficient
manner to meet the needs of multiple stakeholders. Network assessments
can help identify new data needs and associated technologies, find
opportunities for consolidation of individual sites into multi-
pollutant sites, and identify geographic areas where network coverage
should be increased or decreased based on changes in population and/or
emissions. The EPA has already issued draft guidance to describe the
possible techniques that States can use in developing their
assessments, and has purposely limited the required elements to provide
flexibility in the amount of resources that would be required. After
consideration of the comments, EPA has retained the network assessment
requirement in this final rule. In light of the concerns raised about
the resource requirements needed to complete network assessments, the
deadline for the first required assessment under this final rule has
been delayed an additional year to July 1, 2010.
The EPA is not adopting the proposed requirement for a separate
plan
[[Page 61249]]
establishing a network of PM10-2.5 stations as an addendum
to the annual monitoring network plan (see 71 FR 2740, 2779) since the
only required PM10-2.5 monitoring will take place as part of
the NCore multi-pollutant stations, already covered by the proposed
plan due July 1, 2009. The EPA has added clarifying language to this
final rule requiring Administrator approval for the NCore plan due July
1, 2009 and subsequent annual monitoring network plan elements
proposing modifications, consistent with the requirement for
Administrator approval of NCore stations in section 3(a) of appendix D.
The proposed plan element supporting PM10-2.5
suitability tests for NAAQS comparisons likewise is not being adopted
since EPA is not finalizing the proposed PM10-2.5 NAAQS.
The proposed prescriptive wording with reference to public hearings
in the context of reviews of changes to violating PM2.5
monitors and/or community monitoring zones (71 FR 2780) has been
modified to specify that draft plans containing such proposed changes
to PM2.5 networks must be made available for public
inspection and comment by States prior to submission to the EPA
Regional Administrator but that States can design the process for
achieving such goals.
3. Operating Schedules
The EPA proposed that manual PM2.5 monitors at SLAMS be
required to operate on a 1-in-3 day sampling frequency, except under
certain conditions and when approved by the Regional Administrator. See
71 FR 2780. As discussed in section II.E.1 of the preamble to the final
revisions to the PM NAAQS, published elsewhere in this Federal
Register, commenters pointed out a potential bias in the method used to
calculate the 98th percentile form of the 24-hour PM2.5
NAAQS. As explained there, to avoid this potential bias, EPA is
requiring daily sampling at design value sites that are within 5
percent of the 24-hour NAAQS for PM2.5.
The EPA proposed that manual PM10-2.5 samplers at SLAMS
stations must operate on a daily schedule, without a requirement for
any collocated continuously operated FEM PM10-2.5 samplers.
See 71 FR 2780. Numerous commenters noted that a 1-in-3 day sampling
frequency was acceptable for PM2.5 sites and said that the
same sampling frequency for PM10-2.5 would produce
sufficient data for comparison to the proposed 24-hour
PM10-2.5 NAAQS averaged over 3 years. Commenters also noted
the lack of currently available continuous FEM PM10-2.5
instruments and the burdensome resource requirements associated with
daily sampling requirements using the proposed filter-based FRM.
The proposed requirement for daily PM10-2.5 sampling was
based on a data quality objective system analysis that identified such
a frequency as being a key factor in reducing statistical uncertainty
at concentrations near the level of the proposed 24-hour
PM10-2.5 NAAQS. Since EPA is not finalizing a
PM10-2.5 NAAQS but instead is requiring a more limited set
of PM10-2.5 monitors at NCore sites to support objectives
other than and (obviously) not including NAAQS compliance, additional
flexibility in sampling frequency requirements is appropriate. Although
daily sampling of PM10-2.5 at NCore sites remains a
desirable outcome, and will become a more practical goal with the
advent of continuous FEM monitors in several years, EPA has reduced the
PM10-2.5 sampling frequency requirement in this final rule
to 1-in-3 days.
The EPA proposed reducing the sample frequency requirement for
PM10 manual methods. Reducing the sample frequency for
PM10 was possible since EPA had proposed to have daily
sampling of PM10-2.5 to support protection from thoracic
coarse particles. As published elsewhere in today's Federal Register,
EPA is retaining the 24-hour PM10 standard and not
finalizing a PM10-2.5 standard. The EPA is also only
finalizing a limited network of PM10-2.5 monitors at multi-
pollutant NCore stations for scientific purposes. Therefore, since the
existing requirement for PM10 sample frequency is for daily
sampling for the site with the expected maximum concentration in each
area, and previous assessments of the 24-hour standard demonstrates
that maximizing sample frequency will minimize decision errors, EPA is
retaining the existing daily sample frequency requirement for the site
with expected maximum concentration in each area. This existing
requirement also allows for other sites in the same area to operate on
a 1-in-6 day sample frequency. Sample frequency relief is possible for
expected maximum concentration sites that are significantly away from
the 24-hour PM10 NAAQS and in seasons exempted by the
Regional Administrator.
4. Monitoring Network Completion for PM10-2.5 and NCore
Sites
The proposed requirement for specified numbers of
PM10-2.5 sites to be physically established no later than
January 1, 2009 is not included in this final rule. However, by January
1, 2011, States must implement the less extensive monitoring for
PM10-2.5, including speciation sampling, as part of the
generally-applicable requirement to operate NCore multipollutant
monitoring stations by that date. A plan for the implementation of the
required NCore multipollutant monitoring stations, including site
selection, is due July 1, 2009.
Little comment was received on the requirement for the NCore
multipollutant sites to be physically established no later than January
1, 2011, and that requirement remains unchanged in this final rule as
EPA continues to believe that this is practical and desirable.
5. System Modifications
In part, EPA started this rulemaking based on the recognition by
EPA and leaders of State and local monitoring agencies that State/local
monitoring networks should be modified to reduce some types of
monitoring activity in some areas and to begin new types of monitoring.
The EPA proposed rule changes to revise the minimum required number of
monitors for ozone (O3), PM2.5, lead (Pb), and
PAMS pollutants and to eliminate altogether the minimum number of
required monitors for carbon monoxide (CO), sulfur dioxide
(SO2) and nitrogen dioxide (NO2) in order to
utilize scarce resources more productively by allowing for reductions
in the number of monitoring sites where appropriate. See 71 FR 2729.
The EPA stated in the proposal that the remaining requirements for
the minimum number of monitors for Pb, PM2.5, and
O3 were intended to be necessary but not always sufficient
to meet the requirements in section 110(a)(2)(B) of the Clean Air Act
(CAA) that State implementation plans (SIPs) provide for operation of
appropriate systems to monitor, compile, and analyze data on ambient
air quality. Similarly, although EPA believes that one-size-fits-all
rules for the number of CO, SO2, and NO2 monitors
are no longer appropriate in light of the rarity of NAAQS violations
for those pollutants, EPA believes that some monitoring should be
continued in many areas for these pollutants. Accordingly, EPA proposed
to continue to require States to propose changes in their monitoring
networks, including discontinuation of monitors, and obtain EPA
approval before making changes, even when the remaining minimum
requirements, if any, for number of monitors would still be met after
the
[[Page 61250]]
changes. The EPA approval would be given by the Regional Administrator,
usually through approval of the annual monitoring network plan, except
for changes involving NCore sites, PAMS sites, and PM2.5
speciation trends sites which would require Administrator approval.
While local situations need to be considered individually, EPA
proposed six criteria for approval of requests to discontinue monitors.
See 71 FR 2749. To summarize, the six criteria addressed: (1) Any
monitor which could be shown to have a low probability of future
violations; (2) a CO, PM10, SO2, or
NO2 monitor that has been reading consistently lower than
another monitor in the same area; (3) any highest reading monitor that
has not indicated any NAAQS violation in the previous 5 years and for
which the approved SIP provides for an alternative to continued
monitoring; (4) any monitor which cannot be compared to a NAAQS because
of siting considerations; (5) any monitor designed only to measure
transport from upwind areas if another transport monitor were replacing
it; and (6) any monitor for which logistical problems make continued
operation at the current site impossible. Situations not addressed by
these criteria would be considered on a case-by-case basis.
The EPA received a number of comments on the proposed removal of
the minimum monitoring requirements for some of the criteria
pollutants, on the revision of the minimum numbers of monitors for
other criteria pollutants, on the six proposed criteria for
discontinuing monitors, and on the issue of discontinuing monitors more
generally, mostly from State and local monitoring agency officials.
This final rule provisions on minimum numbers of monitors for
O3, PM2.5, PM10, and Pb are discussed
in section V.E of this preamble. Comments on the other parts of the
proposal are addressed here. A few commenters specifically endorsed all
or part of these proposals, or at least the intention to facilitate
reductions in unnecessary or duplicative monitoring activities. Most
commenters expressed concern over the proposals.
A number of commenters appear to have interpreted the proposals as
indicators of network reductions EPA intended to require monitoring
agencies to make, and expressed opposition to such reductions. The EPA
clarifies here that EPA believes that proposals for network
modifications should generally be initiated by the monitoring agency;
EPA does not intend to compel any agency to remove any monitor. The
proposals related to network modifications, and the provisions in this
final rule, govern only EPA's consideration of changes which monitoring
agencies seek to adopt. The EPA recognizes that funding constraints may
require agencies to discontinue monitors that they otherwise would
operate, but this reinforces the need for EPA review and the usefulness
of having criteria for discontinuance to govern that review.
A few commenters suggested that EPA include in the rule or provide
via guidance specific formulas or calculation procedures regarding the
estimation of the probability of a future NAAQS exceedance, which is
the basis of the first of the six proposed adjudicative criteria. The
EPA intends to provide guidance on this matter in the future, but we
believe that binding formulas or procedures in rule form would preclude
development of better general procedures and the sort of case-specific
analysis of unique factors that is likely to be appropriate in some
situations.
A number of commenters stated that the six proposed criteria were
overly focused on whether a monitor is providing data for use in making
comparisons to the NAAQS for purposes of attainment/nonattainment
findings, and that decisions to remove or retain a monitor should also
recognize the utility of the monitor in satisfying other required
monitoring objectives. Section 1 of the proposed appendix D of 40 CFR
part 58 stated that air monitoring networks must be designed to meet
three monitoring objectives: (1) Providing air pollution data to the
public; (2) supporting compliance with ambient air quality standards
and emission strategy development; and (3) supporting air pollution
research studies. Some commenters pointed out that EPA has articulated
in the draft National Ambient Air Monitoring Strategy \11\ seven
objectives for the NCore multipollutant monitoring stations
(overlapping in part with the three objectives in section 1 of appendix
D) and stated that single-pollutant stations should be considered to be
part of an overall network to meet these objectives. The EPA agrees
that these two sets of overlapping objectives are important and that
monitors should not be discontinued without regard to whether these
objectives will continue to be met, but EPA believes the proposed
criteria, along with other provisions regarding approval of annual
monitoring network plans and periodic network assessments, protect the
required monitoring objectives. The paragraphs below address two
objectives that were most often mentioned by commenters.
---------------------------------------------------------------------------
\11\ ``Draft National Ambient Air Monitoring Strategy,''
December 2005.
---------------------------------------------------------------------------
Several commenters stated that ambient monitoring can serve as a
continuing check on the compliance of a specific source, or sources in
the aggregate, with applicable emissions limits. The EPA believes that
given that factors such as wind direction, dispersion conditions, and
atmospheric reactivity conditions can greatly influence the
relationship between emissions and ambient concentrations, situations
are infrequent in which ambient monitoring is a critical, or the most
important, element of source compliance monitoring. Other EPA rules
address requirements for direct emissions and compliance monitoring for
many types of sources. Ambient monitoring agencies will have the option
of continuing to operate ambient monitors they feel are useful for this
objective.
Some commenters stated that the ability to track trends in air
quality and assess whether those trends are consistent with trends
expected from the emission control program in general or from specific
control measures (i.e., accountability) could be impaired if too many
existing monitors are removed. The EPA believes that tracking trends is
most important for O3, PM2.5, and PM10
because these are the NAAQS with more than a few remaining
nonattainment areas. For these pollutants the revised requirements in
this final rule for minimum number of monitors, the new requirement for
NCore multipollutant monitoring stations, and the interest of
monitoring agencies in continuing these types of monitoring as
indicated by the comments themselves will, in EPA's opinion, result in
networks that are appropriately robust for tracking trends and
assessing causal factors. The EPA believes that the availability of
multiple collocated and time resolved measurements at NCore sites will
be a major advantage in this work.
The Response to Comments document available in the docket explains
in more detail how the other objectives mentioned by commenters are
consistent with the six proposed criteria.
Accordingly, this final rule mirrors the proposals, with the
following four exceptions:
(1) In the first criterion, which as proposed would have allowed
the removal of a monitor for any criteria pollutant if it has shown
attainment over the last five years and has less than a 10 percent
probability of exceeding 80 percent of the NAAQS over the next three
years and if it is not specifically
[[Page 61251]]
required by the attainment plan or maintenance plan, this final rule
also conditions the removal of the last remaining SLAMS monitor in a
nonattainment or maintenance area on the attainment plan or maintenance
plan not having any contingency measure triggered by air quality
concentrations. If a plan does have such a trigger, a plan revision to
remove that trigger would have to be adopted by the State and approved
by EPA. The EPA will address the requirements for such a revision at a
future date.
(2) While the preamble described a sixth criterion for approval of
State proposals to discontinue a monitor, having to do with logistical
problems at a current site, the proposed rule text inadvertently
omitted this criterion. This final rule includes it.
(3) The second and third criteria have been slightly revised to
make them applicable also to the lower reading monitor of a pair that
are in the same attainment area and county, and not just to the lowest
reading monitor of a pair that are in the same nonattainment area or
maintenance area. A commenter pointed out the need for this revision to
achieve the obvious intention of the proposal.
(4) The third proposed criterion, worded to apply only to ``the
highest reading monitor * * * in a county,'' required that a described
monitor could be removed only if the approved SIP provided for a
specific, reproducible approach to representing the air quality of the
affected county in the absence of actual monitoring data. While EPA
intended the highest reading monitor to be addressed in this third
criterion, EPA did not intend to preclude the possibility that a lower
reading monitor ineligible for removal under the first two criteria
could be addressed also. This final rule revises the criterion to
encompass any monitor not eligible for removal under the first two
criteria where applicable.
6. Annual Air Monitoring Data Certification
The EPA proposed a shorter timeframe for States to submit the
annual letter certifying ambient concentration and quality assurance
data to the Administrator. See 71 FR 2749. Under current requirements,
States have until July 1 to certify data from January 1 to December 31
of the previous year. For data collected in 2006, for example, the
annual certification letter is due no later than July 1, 2007. Under
the proposed requirement, the schedule for certification would be moved
up 60 days, with the data certification letter required under the
accelerated deadline to be due by May 1, 2009, for data collected in
2008. The EPA proposed this change to provide opportunity for an
earlier start and completion for nationwide designation actions, to
provide States and the public with earlier design values in time for
most ozone seasons, and to support other data uses that could benefit
from earlier data certification.
In response, some commenters expressed reservations about the
accelerated schedule as it applies to all submitted data, while others
supported the proposal for continuous instruments that collect and
report hourly data but not for data requiring lab analysis for samples
collected in the field. These commenters were concerned about the
feasibility and cost of meeting an accelerated schedule. The EPA notes
that some States have recently provided certifications for filter-based
data ahead not only of the July 1 deadline, but also of the proposed
May 1 deadline, when such certifications were deemed advantageous by
the States for data uses such as PM2.5 nonattainment
designations. This suggests that all States could be capable of
certifying data by the proposed May 1 deadline, if not earlier, if they
invest in needed improvements in information technology or efficiencies
in administrative procedures. Therefore, this final rule includes the
proposed May 1 deadline. In recognition of the time necessary for
States to adjust to the accelerated certification requirement, the
implementation date has been delayed 1 year, until May 1, 2010, for
data collected in 2009.
One commenter questioned the types of annual summary reports that
would required to be submitted with the data certification letter,
finding the proposed requirements of 40 CFR 58.15(b) unclear. The EPA
notes that different reports were mentioned in the proposal to clarify
the difference between SLAMS and SPM monitors (only FRM, FEM, and ARM
SPM monitors are required to be certified) and to ensure that annual
summary reports are provided for both types of monitors. Providing one
annual summary report for certification of both SLAMS and SPM data is
appropriate. An additional report providing a summary of precision and
accuracy data is necessary to demonstrate that applicable monitors meet
appendix A criteria.
7. Data Submittal
The EPA proposed to reduce the data reporting requirements
associated with PM2.5 FRMs to ease the data management
burden for monitoring agencies. See 71 FR 2748. The following Air
Quality System (AQS) reporting requirements were proposed for
elimination: Maximum and minimum ambient temperature, maximum and
minimum ambient pressure, flow rate coefficient of variation, total
sample volume, and elapsed sample time. AQS reporting requirements were
retained for average ambient temperature and average ambient pressure,
and any applicable sampler flags.
The EPA also proposed a requirement for the submission of data on
PM2.5 field blank mass in addition to PM2.5
filter-based measurements. See 71 FR 2749. Field blanks are filters
which are handled in the field as much as possible like actual filters
except that ambient air is not pumped through them, to help quantify
contamination and sampling artifacts. This requirement only applies to
field blanks which States are already taking into the field and
weighing through their laboratory procedures.
Commenters supported the proposed changes to data submittal
requirements and they are being finalized without modification. The
requirement for reporting of field blank mass data begins with filters
collected on or after January 1, 2007.
8. Special Purpose Monitors
The January 17, 2006 proposal included a background explanation of
the historical distinctions between regular air monitors and special
purpose monitors (SPMs) with respect to monitoring objectives, siting
actions, quality assurance, and use of data. See 71 FR 2745. The EPA
proposed a revision of the definition of SPM, to the effect that any
SPM must be in excess of the required minimum number of monitors and
that designation of a monitor as an SPM be made by the State. The EPA
also proposed that States would continue to be able to choose to start
and stop SPMs at will, without needing EPA approval and that States be
required to submit all data from SPMs to the AQS operated by EPA. In
addition, EPA proposed that States follow 40 CFR part 58 appendix A
quality assurance requirements for any SPM that utilizes a FRM, FEM, or
ARM instrument and which is sited consistently with the requirements of
appendix E (which does not apply to SPMs on a mandatory basis). The
existing rule provides that States follow these requirements only if
the data from the SPM are intended by the State for use in attainment/
nonattainment determinations.
The EPA also proposed that data from the first 2 years of operation
of a SPM (even if using a FRM, FEM, or ARM
[[Page 61252]]
instrument and meeting appendix A and E requirements) would not be used
by EPA in attainment/nonattainment findings for PM2.5 or
O3 if the monitor stopped operating by the end of those 2
years. See 71 FR 2745. For CO, SO2, NO2, Pb, and
the 24-hour PM10 NAAQS, EPA proposed that data from the
first 2 years of operation of a SPM would not be used by EPA for
nonattainment redesignations but that such data would be considered
when determining whether a nonattainment area had attained the NAAQS.
The reasons for this distinction by pollutant had to do with
differences in the form of the respective NAAQS and whether the EPA
action in question is mandatory or discretionary. These reasons were
explained in detail in the preamble to the proposal. Finally, EPA
proposed that currently operating monitors not already designated as
SPMs could not be designated as SPMs after January 1, 2007.
The EPA received many comments on these issues, mostly from State
and local air monitoring officials but also from two industry groups.
No commenter objected to the flexibility States have to start and stop
SPMs. That flexibility is retained in this final rule.
Some commenters pointed out an ambiguity in the proposed
requirement that data from SPMs be submitted to AQS. The EPA intended,
but did not clearly state in the proposal, that this requirement apply
only to SPMs that are FRMs, FEMs, or ARMs and that are operated
consistently with the requirements of 40 CFR 58.11 (network technical
requirements), 40 CFR 58.12 (operating schedule), and part 58, appendix
A (quality assurance requirements). These would be the SPMs that
produce data that will be of most interest to EPA and the public,
because except for possible inconsistencies with the siting
requirements of appendix E to part 58, these are the type of data which
can be compared to the respective NAAQS. This final rule provides this
clarification.
One commenter suggested that the specific reference to the AQS data
system be made more general, to provide for the development and use of
other suitable data submission systems in the future. This comment is
relevant to all monitoring data, not just data from SPMs. This final
rule retains references to AQS. If AQS is replaced or supplemented with
approved alternatives in the future, terminology can be updated at that
time.
One State official supported the proposal that SPMs be subject to
the regular quality requirements of appendix A, if the SPM is a FRM,
FEM, or ARM. All other commenters on this issue contended that States
should be allowed more flexibility. Most of these commenters agreed
that regular quality assurance practices were desirable generally, but
stated that practical difficulties can arise at a specific SPM site,
such that requiring regular quality assurance practices would
effectively mean that the SPM could not be legally operated at all and
the useful data it could have provided would be lost to users.
After considering these comments, EPA continues to believe that
regular quality assurance practices are practical and of reasonable
cost and feasibility in nearly all situations, as shown by successful
adherence to these practices at thousands of regular monitoring
stations. They are appropriate in most cases and should be the
presumptive requirement. As proposed, this final rule provides for a
transition period by delaying this requirement until January 1, 2009.
However, EPA recognizes that unusual situations may exist in which
exceptions should be allowed. For example, a State, perhaps with EPA
encouragement, might operate an automated O3 monitor year-
round but have difficulty getting personnel and equipment to the site
regularly in winter due to road conditions. This final rule allows the
Regional Administrator to approve other appropriate quality assurance
practices if the requirements of 40 CFR part 58 appendix A would be
physically and/or financially impractical due to physical conditions at
the monitoring site and the quality assurance practices are not
essential to achieving the intended data objectives. This approval can
be given separately, or as part of the approval of the annual
monitoring plan. Approval of alternative quality assurance practices
for all or part of the year does not qualify the affected data from an
affected SPM for comparison to the relevant NAAQS.
Most of the comments received on the SPM proposals addressed the
application of SPM data to attainment/nonattainment findings and
designations. One citizen supported the proposal. About 20 commenters
argued for a general, indefinitely long prohibition on the use of data
from SPMs for nonattainment findings and designations, for States to
have a way of blocking EPA from using particular SPM data indefinitely,
or for States to be able to negotiate in advance with EPA for
particular SPM data to not be used. Those commenters who explained
their position generally stated that the risk of a nonattainment
finding would discourage voluntary special purpose monitoring that
could benefit air quality management.
In the proposal preamble (71 FR 2745, January 17, 2006), EPA stated
that it understood and to some degree sympathized with the thrust of
very similar input EPA had received during the development of the
proposed rule, but that EPA believed that under the CAA EPA may not
legally ignore technically valid data from FRM and FEM (and by
implication and logical extension ARM) monitors when making attainment
or nonattainment determinations. The comments have not provided EPA
with any reason to change this view of our legal obligation. There are
only two situations where EPA would not have to consider such data. One
situation is when the data would be insufficient for making a finding
because it is of insufficient duration given the averaging period or
form of the relevant NAAQS. This was the basis for the proposal
concerning PM2.5 and O3 for which the form of the
NAAQS requires 3 years of data.
The other situation is when EPA has the discretion to simply not
make a finding or to take an action, for example by taking no action to
redesignate an area to nonattainment even though a SPM indicates a new
violation of a NAAQS subsequent to the area's initial designation as
attainment. This was the basis for the proposal concerning the CO,
SO2, NO2, Pb, and PM10 NAAQS. Unlike
the PM2.5 and O3 NAAQS, the NAAQS for these
pollutants have forms that allow a nonattainment finding based on only
1 or 2 years of data, either because the NAAQS is explicitly based on
only one year of data or because a single year of data may include so
many exceedances that it is certain that the average number of expected
exceedances over three years will be greater than one. However, for
these other NAAQS, EPA does not have a mandatory duty to make
nonattainment redesignations until such time as the NAAQS are revised.
In the absence of either a NAAQS revision or a State request for
redesignation, the Administrator has discretion in determining whether
to redesignate an area based on data from a SPM which has operated for
two years or less. The EPA does regard air quality violations
seriously, and does expect States to take actions to reduce air quality
to healthy levels in any areas that are experiencing violations.
However, EPA recognizes that there are other ways to address such
violations besides redesignating an area as nonattainment. For example,
EPA can work directly with a State and nearby industries to take
appropriate actions to reduce emissions that are
[[Page 61253]]
contributing to the violation. The EPA has worked in this way with
States in the past. In the case of PM10, EPA stated in
section VII.B of the preamble to the NAAQS rule (printed in today's
Federal Register) that because EPA is retaining the current 24-hour
PM10 standards, new nonattainment designations for
PM10 will not be required under the provisions of the Clean
Air Act.
With respect to the second situation, applicable to the CO,
SO2, NO2, Pb, and 24-hour PM10 NAAQS,
EPA believes it could have extended the proposed 2-year exclusion from
use of SPM data in making nonattainment findings to a longer period.
However, such a provision could exclude more data than appropriate and
could prevent consideration of violations in making nonattainment
decisions even when a SPM monitor has shown violations over 3 or more
years. The EPA believes that in some and perhaps many situations like
this, it would be good policy to avoid a nonattainment designation and
to find other less prescriptive approaches to reducing risk to public
health. EPA also believes, however, that it could be appropriate to
base a nonattainment designation on such data in some other cases,
where a nonattainment designation is the appropriate way to deal with a
long-term nonattainment problem. Since under the final rule EPA still
has the discretion not to make nonattainment redesignations based on
three more years of data if EPA so chooses, EPA concludes the
appropriate approach is not to universally extend the exclusion and
rather rely on the Administrator's discretion to redesignate areas only
in appropriate cases.
This final rule follows the proposed approach for use of data from
SPMs. The EPA would like to emphasize, however, that States and other
parties will have practical ways of obtaining useful information using
SPMs without risk of a nonattainment redesignation. In many situations,
the potential problem to be investigated, or the place under
investigation, is such that a FRM, FEM, or ARM instrument meeting the
siting requirements of 40 CFR part 58, appendix E is not the only
suitable measurement system, and may not even be a preferred way to
measure. For example, there are many commercially available
PM2.5 monitors that lack FRM, FEM, or ARM status that
nevertheless would be suitable for an initial study of PM2.5
concentrations in an unmonitored area of interest. In some other cases,
2 years may be sufficient to achieve the study objectives. Finally,
under the 1997 rule (see statement at 71 FR 2719 and section 2.8.1.2.3
of appendix D to part 58 of the 1997 rule), \12\ a SPM that is not
population-oriented may not be used in comparisons to the
PM2.5 NAAQS; this may be the situation in some studies
focusing on near-source impacts as well as in some studies of transport
of air pollution from rural upwind areas. If the Regional Administrator
has approved alternative quality assurance practices in place of the
requirements of appendix A, the data from the affected SPM are not
eligible for comparison to the relevant NAAQS.
---------------------------------------------------------------------------
\12\ EPA is recodifying this provision in section 58.30 of the
final monitoring rule, but is not reconsidering or otherwise
reevaluating it.
---------------------------------------------------------------------------
In reviewing comments about SPMs, EPA noticed that the proposed
rule text for 40 CFR 58.11(d) implied that all SPMs using FRM, FEM, or
ARM methods must meet appendix E siting requirements. This was not our
intention, as the study objective for a SPM may require it to be
located inconsistently with appendix E requirements. The implied
restriction in 40 CFR 58.11(d) as proposed conflicted with an explicit
statement to the contrary in 40 CFR 58.20(b) as proposed. Removing this
implication is certainly in keeping with the sense of most SPM-related
comments, which supported flexibility for States to operate SPMs as
they choose. The promulgated version of 40 CFR 58.11(d) is drafted so
as to remove this implied restriction. Data from a SPM not sited
consistently with appendix E are not eligible for comparison to the
respective NAAQS, unless the State has requested and EPA has approved a
waiver of these criteria.
In the course of considering all the public comments on SPMs, EPA
realized that the proposed restriction on designating pre-existing
SLAMS monitors as SPMs after January 1, 2007 would have the effect of
preventing a State from switching a monitor to SPM status even if EPA
had approved the outright removal of that monitor under other
provisions. This could be counter-productive. This final rule provides
that if EPA has approved the discontinuation of a SLAMS monitor, the
State may choose to retain the monitor and redesignate it to be a SPM.
Such a monitor could be removed later without further EPA approval.
9. Special Considerations for Data Comparisons to the National Ambient
Air Quality Standards
By way of background, the preamble to the proposed monitoring rule
provided an explanation of when and how monitoring data are considered
comparable to the respective NAAQS under existing rules and EPA
policies. See 71 FR 2719-20. The EPA also proposed to relocate one of
the provisions mentioned in the discussion, proposing to move pre-
existing PM2.5 rule language currently found in section
2.8.1.2.3 of appendix D to 40 CFR 58.30 of subpart D without
substantive change. This relocation would provide a more prominent rule
location for monitoring requirements detailing the comparability of
ambient data to the PM2.5 NAAQS. See 71 FR 2782. One
commenter objected, not to this proposed rearrangement of rule
language, but rather to the underlying existing (1997) requirement that
PM2.5 sites must be population-oriented to be comparable to
the PM2.5 NAAQS. This commenter stated that EPA had failed
to justify any benchmark for defining an area as population-oriented.
Another commenter challenged whether EPA had provided an adequate
public health basis for this provision.
The EPA considers these comments to be outside the scope of the
proposal. EPA noted in the preamble to the monitoring proposal that
some existing regulatory language was being reprinted without change
and that such reprinting was done solely for the readers' convenience
to aid in viewing the proposal in a single context (71 FR 2712). EPA
also stated that all of the background description of existing
regulatory provisions--including the provision the commenters
challenged--was presented not to reexamine any of the background
provisions but rather ``to facilitate informed public comment'' on
certain aspects of the proposal other than these background provisions.
These other provisions were ``requirements for the proposed
PM10-2.5 NAAQS'', ``provisions for special purpose
monitors'', provisions ``related to the required spacing between ozone
monitors and roadways'', and ``certain quality assurance requirements''
(71 FR at 2719). EPA thus did not seek comment on, reconsider, or
otherwise reopen the pre-existing provision regarding population-
oriented PM2.5 monitors (or any of the other provisions
recited in the background section). The EPA notes, however, that the
pre-existing rule and this final rule do provide the same definition of
population-oriented, in 40 CFR 58.1 Definitions, which while not
quantified in terms of population affected has served to guide
PM2.5 monitor placement and interpretation of monitoring
data since 1997.
The most controversial portion of this part of the proposal dealt
with issues pertaining to the proposed NAAQS for
[[Page 61254]]
PM10-2.5. The EPA proposed a new five-part suitability test
for the comparison of PM10-2.5 data to the proposed
qualified PM10-2.5 indicator. This test included an
urbanized area population criterion, a block group population density
criterion, a requirement for sites to be population oriented, an
exclusion for source-influenced microscale sites, and a site-specific
assessment to insure that data were dominated by certain sources of
concern. See 71 FR 2736-2738. The EPA received extensive comment on the
proposed PM10-2.5 qualified indicator and on the proposed
PM10-2.5 NAAQS five-part site-suitability test. These issues
are now moot since EPA is not adopting a NAAQS using a
PM10-2.5 indicator. See also section III.C of the preamble
to the final rule adopting revisions to the PM NAAQS which explains why
EPA did not adopt the proposed qualified indicator for thoracic coarse
particles and why the proposed monitoring suitability criteria proved
to be inappropriate.
C. Appendix A--Quality Assurance Requirements for State and Local Air
Monitoring Stations and Prevention of Significant Deterioration Air
Monitoring
A quality system provides a framework for planning, implementing
and assessing work performed by an organization and for carrying out
required quality assurance (QA) and quality control (QC) activities.
The proposed amendments to 40 CFR part 58, appendix A were intended to
provide the requirements necessary to develop quality systems for
monitoring the pollutants of SO2, NO2,
O3, CO, PM2.5, PM10 and
PM10-2.5 at SLAMS stations including NCore stations, PAMS,
and Prevention of Significant Deterioration (PSD) networks, and SPM
stations using FRM, FEM, or ARM monitors. The proposed revisions
addressed responsibilities for implementing the quality system for EPA
and monitoring organizations. They also addressed adherence to EPA's QA
policy, DQOs, and the minimum QC requirements and performance
evaluations needed to assess the data quality indicators of precision,
bias, detectability, and completeness. In addition, the proposed
amendments described the required frequency of the QC requirements and
performance evaluations, the data to be collected, and the statistical
calculations for estimates of the data quality indicators at various
levels of aggregation. The revised statistical calculations would be
used to determine attainment of the DQOs. The proposed amendments also
addressed required auditing programs to help determine and ensure data
quality comparability across individual monitoring programs.
The EPA received some comments expressing concerns about the
funding of the quality system. Funding issues are addressed in section
III.E of this preamble. Substantive and procedural issues are addressed
here.
1. General Quality Assurance Requirements
The EPA proposed to revise or include a number of general QA
provisions that would serve to consolidate information and to ensure
conformance to the QA requirements specified in EPA Order 5360.1 A2.
The EPA proposed to consolidate the QA requirements for SLAMS and
PSD stations from two separate appendices, 40 CFR part 58, appendices A
and B, into one single appendix A because both programs have similar QA
requirements. See 71 FR 2725. The EPA received only endorsements on the
proposed consolidation and therefore this final rule consolidates these
appendices.
The EPA proposed to revise the part 58 appendix A to conform to the
current EPA Quality Assurance Policies in EPA Order 5360.1 A2 which
requires agencies that accept Federal grant funding for their air
monitoring programs to have a QA program with certain elements
including quality management plans (QMPs), quality assurance project
plans (QAPPs), and the identification of a QA management function. EPA
received three sets of comments endorsing the revision and received one
comment expressing concern about the identification of the QA manager
function. See 71 FR 2725. The proposed regulation would not have
required that monitoring organizations identify a QA manager but would
have required that they provide for a QA management function, which
provides for independent oversight of the ambient air monitoring
quality system. The EPA feels that the proposed language captures the
essence of the requirements in EPA Order 5360.1A2, while accommodating
the diverse nature of the ambient air monitoring community which is
made up of large and small (local and Tribal) organizations. Consistent
with the majority of positive feedback, and the need for conformance to
the EPA Order, this final rule matches the proposed rule on this point.
The EPA proposed to revise the QA program by emphasizing the DQO
process. See 71 FR 2725. A DQO is a qualitative and quantitative
statement that defines the appropriate quality of data needed for a
particular decision--for example, the data quality necessary for EPA or
a monitoring organization to make data comparisons against the NAAQS.
The DQOs help to establish the requirements for the data quality
indicators of precision, bias, completeness, and detectability and the
rationale for the acceptance criteria for these indicators. The EPA
received a number of endorsements on this approach and did not receive
negative comments. This final rule matches the proposed rule.
2. Specific Requirements for PM10-2.5, PM2.5,
PM10 and Total Suspended Particulates
The EPA proposed to revise some of the PM2.5 and
PM10 QA requirements in an attempt to provide consistency in
implementation and assessment. Since PM10-2.5 monitoring was
proposed to be required, EPA included similar QA requirements for this
monitoring. These requirements included the implementation of flow rate
audits conducted by the monitoring organization, collocated monitoring,
and performance evaluations.
The EPA proposed to make all the requirements for flow rate
verifications and audits consistent among the PM10-2.5,
PM2.5, and PM10 methods. See 71 FR 2728. This
requirement would have increased the audit frequency for
PM10 monitoring and decreased the audit frequency for
PM2.5 monitoring. Most commenters endorsed the proposed
approach but a few commenters voiced concerns regarding the increased
frequency for high-volume samplers for PM10 and total
suspended particulates (TSP) which operate somewhat differently and are
not as easy to audit. The EPA reviewed the comments and revised the
flowrate verification requirement from monthly to quarterly for the hi-
volume manual instruments sampling for PM10 and TSP only.
The EPA proposed to revise the sampling frequency for the
implementation of the PM2.5 Performance Evaluation Program
(PEP). See 71 FR 2726. This proposed approach, based on historical
PM2.5 precision and bias data, identified the minimum number
of performance evaluations required for all primary quality assurance
organizations to provide an adequate assessment of bias, rather than
the current requirement that a uniform 25 percent of monitors in a
primary quality assurance organization be evaluated each year. The
revision would establish a suitable sampling frequency of five valid
audits a year for organizations with less than or equal to five
monitoring sites and eight valid
[[Page 61255]]
audits a year for those organizations with greater than five monitoring
sites. The majority of commenters approved of the PEP reduction
frequency. A few commenters suggested that some primary quality
assurance organizations do not need to be audited and said PEP audits
should only focus on those producing inferior results. The EPA
disagrees with this comment and believes that because the PEP program
needs to provide a periodic estimate of bias for each primary quality
assurance organization, the program must be implemented at each primary
quality assurance organization.
There was also a comment suggesting further reductions to the
auditing frequency or requiring the same number of audits over a longer
period of time. The proposed audit cycle is based on 3 years since that
is how many years of data are collected for comparison the
PM2.5 NAAQS. Therefore, the audit cycle frequency was based
on the number of audit values needed to provide EPA the confidence in
our bias estimates at the primary quality assurance organization over a
3 year period. Therefore, this final rule matches the proposed rule.
The EPA proposed to reduce the lower ends of concentration limits
for which collocated data can be used to provide precision estimates.
See 71 FR 2727. The lower ends of concentration limits would be reduced
from 6 micrograms per cubic meter ([mu]/m3) to 3 [mu]/
m3 for PM2.5 and PM10c (low-volume
samplers) and from 20 [mu]/m3 to 15 [mu]/m3 for
PM10 (high-volume samplers). Statistical evaluation of 3
years of PM2.5 and PM10 data revealed comparable
estimates of precision using data from both of these reduced
concentration ranges, and also revealed that the addition of the data
at these lower ranges will increase the level of confidence in the
precision estimates. The majority of commenters endorsed the approach
but there were a few commenters who were concerned that the lower
concentrations, based on the statistics used to estimate precision,
might lead to greater imprecision estimates. The evaluation that EPA
made with the data from these lower concentrations included did not
show any major increase in imprecision compared to omitting those
data.\13\ Since EPA has proposed the use of target upper confidence
limits for statistical assessments and an upper confidence limit is
influenced by sample size, lowering the concentration values tends to
tighten or lower the confidence limits because more data points are
available in the sample and therefore offsets any greater variability
that might be associated with lower concentrations. Therefore this
final rule matches the proposed rule.
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\13\ ``Proposal to Change PM2.5 and PM10
Collocation Sampling Frequency Requriements,'' Mike Papp and Louise
Camalier; November 2005. http://www.epa.gov/ttn/amtic/pmgainf.html.
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Based upon the decision that there is no need to implement a
PM10-2.5 monitoring program broad enough to systematically
determine attainment/nonattainment with a PM10-2.5 NAAQS,
EPA has modified the proposed PM10-2.5 collocation precision
requirement and the Performance Evaluation Program (PEP) requirements
in this final rule. See 71 FR 2726. The proposed quality system for
PM10-2.5 was developed for NAAQS comparison purposes and
would have provided reliable precision and bias estimates at the
primary quality assurance organization level of aggregation. However,
EPA is not adopting a NAAQS using a PM10-2.5 indicator at
this time, so EPA is now requiring a network of PM10-2.5
monitors only at NCore stations. The goal of these monitors will be to
improve our understanding of PM10-2.5, support health
studies for future reviews of the NAAQS, and promote improvements in
the monitoring technology. States may choose to operate additional
PM10-2.5 monitors. With this in mind, the quality system
need not be focused on the data quality assessments at the primary
quality assurance organization level of aggregation but rather can and
should be focused on understanding and controlling the data quality of
each of the methods used to collect PM10-2.5. Also, since it
is now anticipated that a primary quality assurance organization would
have very few PM10-2.5 sites, the proposal, if adopted
without change, would have required almost every NCore site to have a
collocated second PM10-2.5 monitor, and the proposal would
not provide for assessment of FEM precision even if FEMs are approved
and deployed in place of some or most FRMs since as proposed the first
collocation requirement of an FEM in a primary quality assurance
organization would always be with a FRM. To avoid these undesirable
outcomes, this final rule requires fewer collocated samplers than the
proposal would have. Under this final rule, EPA will ensure that
collocated sampling for estimating precision be implemented at 15
percent of FRMs (all FRMs aggregated) and 15 percent of the FEMs of
each method designation. The number of collocated sites would thus be
based on the size of the final PM10-2.5 network. In order to
provide a distribution of collocation across the United States, EPA
will require, at a minimum, one collocated site in each EPA Region. The
Regional Administrator shall select the sites for collocation. The site
selection process will also consider selecting States with more than
one PM10-2.5 site to have one or two of the required
collocations and will aim for an appropriate distribution among rural
and urban sites.
For the PEP, this final rule departs from the proposal by requiring
only one PEP audit at one PM10-2.5 site in each primary
quality assurance organization each year. The proposed rule would have
required five or eight PEP audits for PM10-2.5 in each
organization. See 71 FR 2787, 2788. Since the PEP is already being run,
at present, for the PM2.5 network and it is expected that
the PM10-2.5 FRMs will utilize the same FRMs as the
PM2.5 samplers, the PEP audit for the PM10-2.5
site can count towards the required number of PEP audits for
PM2.5 sites. It will be necessary to place a
PM10c PEP sampler at the NCore site also but, this
incremental requirement will not be a significant additional resource
burden. When and if FEMs are implemented at some PM10-2.5
sites, the PEP audit will be an additional audit at those particular
sites and will require additional resources for auditing.
The incremental cost of placing and operating PM10-2.5
samplers for purposes of tracking precision will also be minor in most
cases. Many of the primary quality assurance organizations that will
implement the PM10-2.5 monitor at NCore sites are required
to implement PM2.5 and PM10 networks. Some or
most of the initial PM10-2.5 deployments will be with manual
FRM instruments, similar to the instruments used in the
PM2.5 networks and to some of the instruments used in the
PM10 networks. The EPA will allow collocated
PM10-2.5 monitors to be included in the primary quality
assurance organization's count for required PM2.5 and
PM10 collocation. In most cases, the primary quality
assurance organization's collocation requirements for FRMs will not
increase overall, since it is not anticipated that any one primary
quality assurance organization will have many additional
PM10-2.5 sites that are not already both PM2.5
and PM10 sites. The only restriction to this aggregated
collocation count will be for monitoring organizations that are
operating high-volume PM10 samplers. Since the
PM10c monitor in a PM10-2.5 FRM will be a low-
volume sampler, PM10 high-volume and PM10 low-
volume samplers cannot be aggregated together in the collocation
[[Page 61256]]
count and at least one collocated monitor must be identified for each
type within primary quality assurance organization. Therefore, it is
expected that the 15 percent collocation requirement for
PM10-2.5 FRMs will not actually increase the overall
collocation burden at the majority of the primary quality assurance
organizations beyond what they would have been required to implement
for their PM10 and PM2.5 networks.
For any FEMs that might be used at PM10-2.5 sites, EPA
will require 15 percent collocation of each method designation or at
least two collocations within each method designation. The EPA will
require two collocations in order to collocate one FEM instrument with
the same method designation to provide estimates of within method
precision and collocate a second with an FRM to provide for an estimate
of bias. These collocations would not necessarily need to be at
separate monitoring sites.
3. Particulate Matter Performance Evaluation Program and National
Performance Audit Programs
The EPA proposed to revise the current regulatory requirements
dealing with responsibilities for independent assessments of monitoring
system performance. See 71 FR 2726. These evaluations are the subject
of sections 2.4 and 3.5.3.1 of the existing (1997) appendix A to 40 CFR
part 58. Section 2.4 of appendix A to 40 CFR part 58 applied to all
NAAQS pollutants and section 3.5.3.1 applied only to PM2.5.
The EPA proposed to revise the text of 40 CFR part 58, appendix A
to cover PM10-2.5 and also to clarify that it is the
responsibility of each monitoring organization to make arrangements
for, and to provide any necessary funding for, the conduct of adequate
independent performance evaluations of all its FRM or FEM criteria
pollutant monitors. The proposed language also clearly indicates that
it is the monitoring organization's choice whether to obtain its
independent performance evaluations through EPA's National Performance
Audit Program (NPAP) and PM2.5 PEP programs, or from some
other independent organization. An independent organization could be
another unit of the same agency that is sufficiently separated in terms
of organizational reporting and which can provide for independent
filter weighing and performance evaluation auditing. The proposed
approach would ensure that adequate and independent audits are
performed and would provide flexibility in the implementation approach.
Monitoring organizations that choose to comply with the revised
provisions of appendix A to 40 CFR part 58 regarding performance
evaluations by relying on EPA audits, for PM2.5,
PM10-2.5, and/or other NAAQS pollutants, would be required
to agree that EPA hold back part of the grant funds they would
otherwise receive directly. These funds would be used by EPA to hire
contractors to perform the audits and to purchase expendable supplies.
To ensure national consistency and effective audits, EPA included
provisions to ensure certification of data comparability for audit
services not provided by EPA and for traceability of gases and other
audit standards to national standards maintained by the National
Institute for Standards and Technology.
The EPA received a broad range of comments on this proposed
revision. The EPA received a few comments in support of these programs
and one commenter felt that the PEP audits should be increased. In
general, the comments expressing concern with the proposed language did
not suggest that these programs were not necessary but were concerned
about some technical aspects of the programs or with funding
implications. Funding issues are addressed in section III.E of this
preamble.
The EPA received a number of comments expressing concerns that
allowing the monitoring agencies to implement the audit programs
themselves or through third parties would increase the variability in
the performance evaluation data. Since one of the major goals in the
historically centralized and federally implemented PEP and NPAP
programs has been the evaluation of data comparability, EPA is also
concerned about any additional variability and its effect on data
comparability. It has been EPA's practice with regard to any State
which already performs these audits to perform side-by-side comparisons
of EPA's equipment and procedures and the State's procedures to ensure
both are producing results of acceptable quality. The EPA has
successfully performed these comparisons with the California Air
Resources Board's audit system. These comparisons will be expanded to
include any additional States which choose to perform audits themselves
or through third parties, rather than ask EPA to do so. During the
comment period, EPA asked the monitoring organizations whether or not,
assuming finalization of the proposed rule changes, they would continue
to use the federally implemented program or perform the audits itself.
For 2007, only three monitoring organizations (besides the one already
implementing NPAP) opted to implement the NPAP and three monitoring
organizations (besides the two already implementing PEP) opted to
implement the PEP. The EPA believes it has the capability to ensure
these State will implement programs will produce data of a quality
comparable to the Federally implemented program.
The EPA also received comments stating concerns about the
stringency of the definition of adequate and independent. Adequacy
refers to the number of audits administered at any primary quality
assurance organization and the technical procedures used in the audits.
This final rule does not require any additional adequacy requirements
above and beyond what EPA currently implements for the federally
implemented program. The EPA evaluates data quality at the aggregation
called ``reporting organization'' (which was changed to ``primary
quality assurance organization'' in the proposal). The EPA feels that
it needs to collect enough data to be able to judge data quality within
each primary quality assurance organization over the same period that
it uses the data for comparison to the NAAQS (3 years).
In the case of the PEP for PM2.5, today's action
requires five audits per year for organizations with five or fewer
sites and eight audits for those organizations with greater than five
sites, the same as proposed. The number of audits aggregated over three
years provides a reasonable estimate of bias at a primary quality
assurance organization within an acceptable level of confidence. For
the NPAP program addressing NAAQS for CO, SO2, Pb, and
NO2, the goal is to perform audits on about 20 percent of
the sites each year, but since there may be a number of high priority
sites within a primary quality assurance organization that should be
audited more often, it is anticipated that NPAP might audit each site
within a primary quality assurance organization over about 7 to 8
years. This 20 percent goal is the current EPA practice, but was not
proposed to be required by rule and, therefore, does not appear in this
final rule.
There were a few comments suggesting that some primary quality
assurance organizations do not need to be audited and that EPA
mandatory audits for CO, SO2, Pb, and NO2 should
only focus on those organizations producing inferior results. The EPA
continues to believe that it is important to develop an estimate of
bias for each primary quality assurance organization. To do this, the
audit program must be
[[Page 61257]]
implemented at each primary quality assurance organization. The NPAP
audits using a through-the-probe approach, which is generally not how
audits are performed by the primary quality assurance organizations
themselves. By auditing some stations within a primary quality
assurance organization each year using the through-the-probe approach,
the NPAP can identify problems which the organization may not be aware
of on its own. Also, EPA continues to believe that it is necessary to
provide an adequate assessment of data comparability of all primary
quality assurance organizations every year.
There were also comments concerning the requirement to use
independent filter weighing laboratories for the implementation of the
PEP. When EPA first implemented the PEP program, EPA established two
independent laboratories to weigh filters for the PEP audits. Due to
program efficiencies, EPA is now using one filter weighing laboratory.
If primary quality assurance organizations implement the PEP
themselves, they should not be able to utilize the same laboratory in
which they weigh their routine sampler filters since any bias or
contamination that might occur at the routine lab will also be ``passed
on'' to the PEP filter. Because the PEP provides an estimate of bias
(systematic error), it is necessary to avoid having a systematic bias
occurring in the routine filter weighing lab affect both the PEP
filters and the routine filters. Primary quality assurance
organizations interested in implementing the PEP themselves have the
option to make arrangements with other State labs, contractor labs, or
utilize the PEP national lab.
The EPA believes that both the NPAP and PEP programs serve as an
integral part of the overall ambient air monitoring program quality
system and provide EPA and the public with independent and objective
assessments of data quality and data comparability. Both programs
provide the only quantitative independent assessments of data quality
at a national level. Therefore, the proposed language was not changed
and this final rule matches the proposed rule.
4. Revisions to Precision and Bias Statistics
The EPA proposed to change the statistics for assessment of
precision and bias for criteria pollutants. See 71 FR 2727. Two
important data quality indicators that are needed to assess the
achievement of DQOs are bias and precision. Statistics in the current
requirements of 40 CFR part 58, appendix A (with the exception of
PM2.5) combine precision and bias together into a
probability limit at the primary quality assurance organization level
of aggregation. Since the standard EPA DQO process uses separate
estimates of precision and bias, EPA examined separated assessment
methods that were statistically reasonable and simple.
For SO2, NO2, CO, and O3, EPA
proposed to estimate precision and bias on confidence intervals at the
site level of data aggregation rather than the primary quality
assurance organization. Estimates at the site level can be accomplished
with the automated methods for SO2, NO2, CO, and
O3 because there is sufficient QC information collected at
the site level to perform adequate assessments.
The precision and bias statistics for PM measurements
(PM10, PM10-2.5 and PM2.5) are
generated at a primary quality assurance organization level because,
unlike the gaseous pollutants, due to costs only a percentage of the
sites have precision and bias checks performed in any year and only a
few times per year. As with the gaseous pollutants, the statistics
would use the confidence limit approach. Using a consistent set of
statistics simplifies the procedures.
The EPA also proposed to change the precision and bias statistics
for Pb to provide a framework for developing and assessing a DQO. See
71 FR 2727. The QC checks for Pb come in three forms: Flow rate audits,
Pb audit strips, and collocation. The EPA proposed to combine
information from the flow rate audits and the Pb audit strips to
provide an estimate of bias. Precision estimates would still be made
using collocated sampling but the estimates would be based on the upper
95 percent confidence limit of the coefficient of variation, similar to
the method described for the automated instruments for SO2,
NO2, CO, and O3.
The EPA received only positive comments on the proposed statistics
and some typographical corrections. This final rule matches the
proposed rule.
5. Other Program Updates
The EPA proposed several QA program changes to update the existing
requirements in 40 CFR part 58 to reflect current program needs and
terminology.
The EPA proposed to remove SO2 and NO2 manual
audit checks. A review of all SLAMS/NAMS/PAMS sites by monitor type
revealed that no monitoring organizations are using manual
SO2 or NO2 methods, nor are any monitoring
organizations expected to use these older technologies. The EPA
received only comments endorsing the removal of the manual audit
checks. Therefore, this final rule matches the proposed rule.
The EPA proposed to change the concentration ranges for QC checks
and annual audit concentrations. The one-point QC check concentration
ranges for the gaseous pollutants SO2, NO2,
O3, and CO were expanded to include lower concentrations.
Lower audit ranges were added to concentration ranges for the annual
audits. Adding or expanding the required range to lower concentration
ranges was appropriate due to the lower measured concentrations at many
monitoring sites as well as the potential for NCore stations to monitor
areas where concentrations are at trace ranges. In addition, EPA
proposed that the selection of QC check gas concentration must reflect
the routine concentrations normally measured at sites within the
monitoring network in order to appropriately estimate the precision and
bias at these routine concentration ranges. The majority of the
comments EPA received on this proposal were positive but EPA received
comments that asked for more guidance on how a monitoring organization
would choose the appropriate audit ranges. The EPA would like to
provide as much flexibility as possible for the monitoring organization
to use their local knowledge of their monitoring sites to choose their
audit concentration ranges. Accordingly, in this final rule, section
3.2.2.1 of appendix A to part 58 establishes a non-binding goal that
the primary quality assurance organization select the three audit
concentration ranges which bracket 80 percent of the routine monitoring
concentrations at the site. So in general, with some minor modification
to address comments, this final rule matches the proposed rule.
The EPA proposed to revise the PM10 collocation
requirement. See 71 FR 2726. Fifteen percent of all PM2.5
sites are required to maintain collocated samplers. For
PM10, the collocated requirements in the existing (1997)
regulation were three alternative values based on the number of routine
monitors within a primary quality assurance organization. For
consistency, the proposed amendments would have changed the
PM10 collocation requirement to match the PM2.5
requirement. This proposed change would make the collocation
requirement consistent for PM2.5 and PM10. The
EPA did not receive any comments on this proposed change. Therefore,
this final rule matches the proposed rule.
The EPA proposed to revise the requirements for PM2.5
flow rate audits.
[[Page 61258]]
See 71 FR 2728. Based on an evaluation of flow rate data and
discussions within the QA Strategy Workgroup,\14\ EPA proposed to
reduce the frequency of flow rate audits from quarterly to semiannually
and to remove the alternative method which allows for obtaining the
precision check from the analyzers internal flow meter without the use
of an external flow rate transfer standard. Most monitoring
organizations participating in the QA Strategy Workgroup considered
auditing with an external transfer standard to be the preferred method
and believed that the quarterly audit data demonstrated the instruments
were sufficiently stable to reduce the audit frequency. The EPA did not
receive any comments on this proposal; therefore, this final rule
matches the proposed rule.
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\14\ The QA Strategy Workgroup consists of EPA, State, and local
staff responsible for monitoring quality assurance activities who
meet informally to exchange information on current monitoring
issues.
---------------------------------------------------------------------------
D. Appendix C--Ambient Air Quality Monitoring Methodology
1. Applicability of Federal Reference Methods and Federal Equivalent
Methods
The EPA proposed that monitoring methods used in the multipollutant
NCore, SLAMS, and PAMS networks were required to be FRMs, FEMs, ARMs,
or where appropriate, other methods designed to meet the DQOs of the
network being deployed. See 71 FR 2731. Specifics on the monitoring
methods proposed for use at each type of site are described below.
The EPA proposed that NCore multipollutant stations must use FRMs
or FEMs for criteria pollutants when the expected concentration of the
pollutants was at or near the level of the NAAQS. For criteria
pollutant measurements of CO and SO2, where the level of the
pollutant is well below the NAAQS, EPA observed that it may be more
appropriate to operate higher sensitivity monitors than typical FRM or
FEM instruments. See 71 FR 2728. In these cases, higher sensitivity
methods were expected to support additional monitoring objectives that
conventional FRMs or FEMs cannot. In some cases, higher-sensitivity gas
monitors have also been approved as FEM and can serve both NAAQS and
other monitoring objectives. Options for high-sensitivity measurements
of CO, SO2, and total reactive nitrogen (NOy) are
described in the report, ``Technical Assistance Document for Precursor
Gas Measurements in the NCore Multipollutant Monitoring Network.''
Comments regarding monitoring methods used at NCore stations are
addressed in section V.E.1 of this preamble.
The EPA proposed that SLAMS use FRMs or FEMs for criteria
pollutants. See 71 FR 2728. The EPA also proposed that these sites have
the additional option of using ARMs for PM2.5. Approved
regional methods are described in section V.D.2 of this preamble.
Photochemical assessment monitoring stations (PAMS) were proposed
to be required to use FRM or FEM monitors for O3, with most
expected to use the O3 ultraviolet photometry FEM and the
nitric oxide (NO) and NO2 chemiluminescence FRM for criteria
pollutant measurements. See 71 FR 2728. Methods for volatile organic
compounds (VOC) including carbonyls, additional measurements of gaseous
nitrogen, such as NOy, and meteorological measurements are
routinely operated at PAMS. Because these measurements are not of
criteria pollutants, the methods were not subject to the requirements
for reference or equivalent methods. However, these methods were
described in detail in the report, ``Technical Assistance Document
(TAD) for Sampling and Analysis of Ozone Precursors.'' \15\
---------------------------------------------------------------------------
\15\ Technical Assistance Document (TAD) for Sampling and
Analysis of Ozone Precursors. U.S. Environmental Protection Agency.
Human Exposure and Atmospheric Sciences Division. EPA/600-R-98/161.
September 1998. Available at: http://www.epa.gov/ttn/amtic/pams.html.
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The EPA proposed that SPM sites have no restrictions on the type of
method to be utilized. While FRM and FEM can be employed at SPM sites,
other methods, not limited to continuous, high-sensitivity, and passive
methods, may also be utilized. Because the SPM provision was designed
to encourage monitoring, agencies could design SPM sites with methods
to meet monitoring objectives that may not be achievable with FRMs or
FEMs. Additional information on SPMs is included in section V.E.8 of
this preamble.
The EPA received several comments on its proposed approach for
ambient air monitoring methodology. Some of these comments expressed
concern that requiring only designated reference or equivalent methods
takes away flexibility and the drive for improvements to air quality
instrumentation. The EPA agrees that some flexibility is desirable for
agencies to use innovative methods that can support other objectives
beyond NAAQS decision making. However, CAA section 319 requires ``* * *
an air quality monitoring system throughout the U.S. which utilizes
uniform air quality monitoring criteria and methodology * * *''. The
EPA recognizes that there may be occasions when a unique method is
better suited to meet a specific monitoring objective that is different
from NAAQS decision making. In these cases, EPA will allow for these
innovative methods, so long as the monitoring agency is not attempting
to use them to meet minimum requirements for the number of monitors for
a given criteria pollutant. For example, a low cost method might be
applied as a SPM to provide short term data for validation of an air
quality model.
2. Approved Regional Methods for PM2.5
The EPA proposed amendments that expanded the allowed use of
alternative PM2.5 measurement methods through ARMs. See 71
FR 2729. The EPA also proposed to extend the existing provisions for
approval of a nondesignated PM2.5 method as a substitute for
a FRM or FEM at a specific individual site to a network of sites. This
approval would be extended on a network basis to allow for flexibility
in operating a hybrid network of PM2.5 FRM and continuous
monitors. The size of the network, in which the ARM could be approved,
would be based on the location of test sites operated during the
testing of the candidate ARM. The proposed amendments would have
required that test sites be located in urban and rural locations that
characterize a wide range of aerosols expected across the network. A
hybrid network of monitors was envisioned to address monitoring
objectives beyond just determining compliance with NAAQS. The hybrid
network was expected to lead to a reduced number of existing FRM
samplers and an increase in continuous ARM samplers that would all be
approved for direct comparison with the applicable forms of the
PM2.5 NAAQS.
Many comments were received on EPA's proposal regarding ARMs for
PM2.5. Several commenters suggested requiring on-going
collocation with an FRM. Commenters also raised concerns about ensuring
data quality, especially in light of the lower level of the 24-hour
PM2.5 NAAQS and therefore the perceived need to ensure that
the statistical criteria are met in each season. One commenter was so
concerned about the data quality issues that the commenter recommended
dropping the ARM provision. Other commenters voiced strong support for
the ARM provision, but also recommended that EPA allow for less
collocation with FRMs than the 30
[[Page 61259]]
percent that was proposed. Several commenters recommended that EPA
allow non-linear data adjustment factors as are used for AIRNow and
mapping purposes.
In reviewing comments on the provision for ARMs, EPA agrees that
data quality issues need to be appropriately addressed. Since ARMs will
be used for several monitoring objectives, including NAAQS attainment/
nonattainment determinations, they must meet the Class III FEM
performance criteria set out in part 53. However, as proposed, these
performance criteria left open the possibility that in cleaner
environments where concentration data approached background levels of
PM2.5 that approved methods may have unacceptable levels of
bias to meet other monitoring objectives. Therefore, the Class III
equivalency criteria, which are the same criteria used for
PM2.5 ARMs, has been strengthened to address concerns about
additive bias in cleaner environments. The EPA performed an extensive
investigation into developing equivalency criteria for PM2.5
continuous methods. One of the conclusions from that process was that
continuous methods, by virtue of being able to provide a sample every
day, generate data with more certainty in decision making than methods
used with lower sample frequencies (i.e., a 1-in-3 day sample
schedule), with all other factors being equal. Although biases can be
seasonal, correlation combined with the other performance criteria will
guard against high biases in one season cancelling out low biases in
another. Together, the performance criteria and the daily sample
schedule will ensure that data quality objectives are met when making
NAAQS decisions with data from ARMs.
With respect to requiring on-going collocation with FRMs at 30
percent of the sites with continuous PM2.5 monitors, EPA has
considered how this would affect agencies with many continuous monitors
and finds it unnecessary to require such a large absolute number of
collocated sites, although the number of collocated FRM under a 30
percent collocation requirement makes sense for smaller networks.
Therefore, this final rule states that monitoring agencies are only
required to have 30 percent collocation of the ARMs they count towards
the applicable minimum number of required FRM/FEM/ARM sites--rounded
up, rather than 30 percent of their full networks of ARMs.
For the issue of non-linear data transformations, this final rule
specifically allows data transformations when using an ARM, including
non-linear ones, so long as the transformations are described in both
the ARM application and the monitoring agency's quality assurance
project plan (or addendum to the QAPP), the transformations are
prospective, and the ARM application provides for details on how often
or under what circumstances they will be recalculated, based on what
data, and which analytical method.
Since participation in seeking approval of ARMs is voluntary and
approval of an ARM applies only in the territory of the agency seeking
approval, no monitoring agency having concerns will be required to
utilize the ARM provisions. However, for many agencies this approach
will offer an opportunity to improve their monitoring network's
utility, by using methods that can serve multiple objectives, while
having lower costs. Therefore, EPA is finalizing the ARM provisions as
proposed, with the exceptions of the additive bias requirement being
strengthened; changes to the required collocation requirement; and
clarifying use of data transformations, including non-linear ones.
Today's final action thus allows State, local, and Tribal
monitoring agencies to independently, or in cooperation with instrument
manufacturers, seek approval of ARMs where PM2.5 continuous
monitor data quality is sufficiently comparable to FRMs for integration
into the agency's PM2.5 network used in NAAQS attainment
findings. The performance criteria for approval of candidate ARMs are
the same criteria for precision, correlation, and additive and
multiplicative bias that have been finalized for approval of continuous
PM2.5 Class III equivalent methods, described in section
IV.C of this preamble. These performance criteria are to be
demonstrated by monitoring agencies independently or in cooperation
with instrument manufacturers under actual operational conditions using
one to two FRM and one to two candidate monitors each. This is a
departure from the very tightly-controlled approach used for national
equivalency demonstration in which three FRM and three candidate
monitors are operated. The ARM will be validated periodically in
recognition of changing aerosol composition and instrument performance.
These validations will be performed on at least two levels: (1) Through
yearly assessments of data quality provided for as part of the on-going
quality assurance (QA) requirements in 40 CFR part 58, appendix A, and
(2) through network assessments conducted at least every 5 years as
described in section V.B.2 of this preamble.
The testing criteria EPA will use for approval of PM2.5
continuous methods as ARMs are intended to be robust but not overly
burdensome. The two main features of testing that are different than
FEMs are the duration and locations of testing. The duration is
expected to be 1 year to provide an understanding of the quality of the
data on a seasonal basis. The locations for testing are expected to be
a subset of sites in a network where the State desires the
PM2.5 continuous monitor to be approved as an ARM. Testing
will be carried out in multiple locations to include up to two Core-
based Statistical Area/Combined Statistical Areas (CBSA/CSA) and one
rural area or small city for a new method. For methods that have
already been approved by EPA in other networks, one CBSA/CSA and one
rural area or small city are required to be tested.
To ensure that approvals of new methods are made consistently on a
national basis, the procedures for approval of methods are similar to
the requirements specified in 40 CFR part 53, i.e., the EPA
Administrator (or delegated official) will approve the application.
However, to optimize flexibility in the approval process, all other
monitoring agencies seeking approval of an ARM that is already approved
in another agency's monitoring network can seek approval through their
EPA Regional Administrator. This approach will provide a streamlined
approval process, as well as an incentive for consistency in selection
and operation of PM2.5 continuous monitors across various
monitoring agency networks.
The QA requirements for approval of continuous PM2.5 ARM
at a network of sites are the same as for FEM in 40 CFR part 58,
appendix A, except that 30 percent--rounded up--of the required sites
that utilize a PM2.5 ARM would be collocated with an FRM and
required to operate at a sample frequency of at least a 1-in-6 day
schedule. The higher collocation requirement would support the main
goal of the particulate matter continuous monitoring implementation
plan, which was to have an optimized FRM and PM2.5
continuous monitoring network that can serve several monitoring
objectives. This collocation requirement is necessary to retain a
minimum number of FRM for continued validation of the ARM, direct
comparison to NAAQS, and for long-term trends that are consistent with
the historical data set archived in the AQS. The collocated sites are
to be located at the highest concentration sites, starting
[[Page 61260]]
with one site in each of the largest population MSA in the network and
working to the next highest-population MSA with the second site and so
forth.
Finally, EPA reiterates that ARMs may be used to measure compliance
with the PM2.5 NAAQS. See section 50.13(b) and (c) (as
published elsewhere in today's Federal Register) (annual and 24-hour
primary and secondary standards are met when designated concentrations
``as determined in accordance with Appendix N'' are met), and Part 50
Appendix N section 1.a (for purposes of section 50.13, PM2.5
can be measured by FRM, FEM, ``or by an Approved Regional Method (ARM)
designated in accordance with part 58 of this chapter'').
E. Appendix D--Network Design Criteria for Ambient Air Quality
Monitoring
1. Requirements for Operation of Multipollutant NCore Stations
The EPA proposed requirements for NCore stations applicable to
States individually that would, in the aggregate, result in the
deployment of a new network of multipollutant monitoring stations in
approximately 60 mostly urban areas. See 71 FR 2730. In the proposal,
most States would have been required to operate one urban station;
however, rural stations could be substituted in States that have
limited dense urban exposures. Such substitution would not change the
goal of having about 20 rural NCore sites. California, Florida,
Illinois, Michigan, New York, North Carolina, Ohio, Pennsylvania, and
Texas would be required to operate one to two additional NCore stations
in order to account for their unique situations. These stations,
combined with about 20 multipollutant rural stations, which were not
proposed to be required of specific States, would form the new NCore
multipollutant network. The rural NCore stations would be negotiated
using grant authority as part of an overall design of the network that
is expected to leverage existing rural networks such as IMPROVE,
CASTNET and, in some cases, State-operated rural sites.\16\
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\16\ To clarify, under the proposed rule, and this final rule,
41 States, the District of Columbia, the Virgin Islands, and Puerto
Rico will be required to operate one NCore site. The other nine
States will be required to operate two or three sites, for a
national total of 62 to 71 required sites. Some of these required
sites might be waived by EPA. The EPA anticipates, but the rule does
not require that some of these sites will be rural. Counting non-
required sites, the goal is a total of about 75 sites, about 20 of
which will be rural.
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These NCore multipollutant stations are intended to track long-term
trends for accountability of emissions control programs and health
assessments that contribute to ongoing reviews of the NAAQS; support
development of emissions control strategies through air quality model
evaluation and other observational methods; support scientific studies
ranging across technological, health, and atmospheric process
disciplines; and support ecosystem assessments. Of course, these
stations together with the more numerous PM2.5,
PM10, O3, and other NAAQS pollutant sites would
also provide data for use in attainment and nonattainment designations
and for public reporting and forecasting of the AQI.
The EPA proposed that these NCore multipollutant stations be
required to measure O2; CO, SO2, and total
reactive nitrogen (NOy) (using high-sensitivity methods,
where appropriate); PM2.5 (with both a FRM and a continuous
monitor); PM2.5 chemical speciation; PM10-2.5
(with a continuous FEM); and meteorological parameters including
temperature, wind speed, wind direction, and relative humidity. See 71
FR 2730. High-sensitivity measurements are necessary for CO,
SO2, and NOy to adequately measure these
pollutants in most air sheds for data purposes beyond NAAQS attainment
determinations. For the other criteria pollutants, EPA proposed use of
conventional ambient air monitoring methods.
At least one NCore station was proposed to be required in each
State, unless a State determines through the network design process
that a site which meets their obligation can be reasonably represented
by a site in a second State, and the second State has committed to
establishing and operating that site. Any State could propose
modifications to these requirements for approval by the Administrator.
While the proposed amendments did not specify the cities in which the
States would have to place their NCore multipollutant monitoring
stations, EPA anticipated that the overall result would be a network
that has a diversity of locations to support the purposes listed
earlier. For example, there would be sites with different levels and
compositions of PM2.5 and PM10-2.5, allowing air
quality models to be evaluated under a range of conditions.
The EPA received several comments on the proposed requirements for
operating the NCore multipollutant monitoring stations. Some commenters
recommended requiring additional NCore monitoring stations for better
spatial coverage and to capture gradients, including specifically
requiring additional rural sites. Regarding methods, a few commenters
recommended not requiring the total reactive NOy
measurement, since this measurement in some but not all cases is little
different from the existing NO2 measurement by
chemiluminescence, which uses the same measurement principle as
NOy.
In reviewing the comments, EPA notes that more NCore sites can be
deployed than required by regulation. For example, in our proposal EPA
stated that it would develop a design of the network for rural sites--
not specifically required of any individual State--that leveraged
existing rural networks such as IMPROVE, CASTNET and, in some cases,
State-operated rural sites. In some cases it may be appropriate to have
enough NCore multipollutant sites to assess gradients; however, in
other areas having enough sites to develop gradients with all the
parameters required of an NCore station may not be needed and would
therefore present an unnecessary burden to the States. Therefore, EPA
is finalizing the NCore network design requirements as proposed.
For required methods, EPA agrees that in areas where the existing
NOX method provides comparable data to the NOy
method, monitoring agencies should be allowed to operate NOX
instead of the more challenging measurement of NOy. However,
EPA notes much of the reason for NOy and NOX
reading being so close may be a positive bias with current typical
NOX (NO + NO2) instruments which may over report
NO2. Since further development of the NOX method
is underway, monitoring agencies which seek waivers for the
NOy method are encouraged to utilize high sensitivity
versions of the chemiluminescence method so that they are capable of
switching from high sensitivity NOX to high sensitivity
NOy in performing gaseous nitrogen measurements. The EPA is
therefore finalizing the required measurements at NCore multipollutant
sites as proposed; however, EPA will allow for waivers of the
NOy method in areas where measured NOX is
expected to provide virtually the same data as NOy. This is
largely expected to be in urban environments until such time as the
NO2 method (and hence the NOX) is sufficiently
improved that having separate measurements of NOy and
NOX provides more useful information than the existing
technology. See also section V.E.7.
The NCore stations are to be deployed at sites representing as
large an area of relatively uniform land use and ambient air
concentrations as possible (i.e., out
[[Page 61261]]
of the area of influence of specific local sources, unless exposure to
the local source(s) is typical of exposures across the urban area).
Neighborhood-scale sites may be appropriate for NCore multipollutant
monitoring stations in cases where the site is expected to be similar
to many other neighborhood scale locations throughout the area. In some
instances, State and local agencies may have a long-term record of
several measurements at an existing location that deviates from this
siting scheme. The State or local agency may propose utilizing these
kinds of sites as the NCore multipollutant monitoring station to take
advantage of that record. The EPA will approve these sites, considering
both existing and expected new users of the data. The NCore
multipollutant stations should be collocated, when appropriate, with
other multipollutant air monitoring stations including PAMS, National
Air Toxic Trends Station sites, and the PM2.5 chemical
Speciation Trends Network sites. Collocation will allow use of the same
monitoring platform and equipment to meet the objectives of multiple
programs where possible and advantageous. Of the approximately 60
required NCore stations, up to 35 existing State-operated multi-monitor
stations are already also operating or preparing to also operate the
high-sensitivity monitors for CO, SO2, and NOy
that are part of the NCore requirement.
Although EPA is retaining the 24-hour PM10 NAAQS for
requisite protection against short-term exposure to thoracic coarse
particles and is not promulgating a PM10-2.5 NAAQS, the
NCore stations are also being required to deploy a PM10-2.5
FRM or FEM to build a dataset for scientific research purposes,
including supporting health studies and future reviews of the PM NAAQS.
Separate PM10 monitoring will not be required at NCore
stations. For many PM10-2.5 methods, including the FRM,
PM10 data will be readily available as part of the
calculated PM10-2.5 measurement. Even if a
PM10-2.5 method that does not report PM10 is
approved as an FEM and is deployed to one or more NCore sites,
PM10 will still be available by virtue of the independent
measurements of PM2.5 and PM10-2.5 (which could
appropriately be summed). Therefore, EPA is not making measurements of
PM10 a requirement of the NCore network. Also, since the
NCore network of PM10-2.5 FRM/FEM is not being used for
attainment/nonattainment determinations, agencies may operate filter
methods on as infrequent a schedule as a 1-in-3 day sampling.
This final rule contains a requirement for PM10-2.5
speciation to be conducted at NCore multipollutant monitoring stations.
The EPA had proposed a requirement for PM10-2.5 speciation
in 25 areas, with the areas required to have this monitoring selected
based on having an MSA population over 500,000 and having an estimated
design value of greater than 80 percent of the proposed
PM10-2.5 NAAQS. This would have concentrated the
PM10-2.5 speciation monitoring in areas that have high
populations and high exposures to PM10-2.5. Since EPA is
requiring PM10-2.5 monitoring at NCore primarily for
scientific purposes, it is more appropriate to have monitoring in a
variety of urban and rural locations so as to increase the diversity of
areas that have available chemical species data to use in scientific
studies. The EPA had already proposed to have chemical speciation for
PM2.5 at NCore stations. The collocation of both
PM10-2.5 and PM2.5 speciation monitoring at NCore
stations is consistent with the multipollutant objectives of the NCore
network and will support further research in understanding the chemical
composition and sources of PM10 and PM10-2.5, and
PM2.5 at a variety of urban and rural locations.
Once these multipollutant NCore stations are established, it is
EPA's intention that they operate for many years in their respective
locations. Therefore, State and local agencies are encouraged to insure
long-term accessibility to the sites proposed for NCore monitoring
stations. Relocating these stations will require EPA approval, which
will be based on the data needs of the host State and other clients of
the information.
The EPA may negotiate with some States, and possibly with some
Tribes, for the establishment and operation of additional rural NCore
multipollutant monitoring stations to complement the stations required
by today's action.
The EPA is in the process of upgrading the CASTNET monitoring
capabilities to allow stations to provide even more useful data to
multiple users. The EPA expects that about 20 CASTNET sites, operated
at EPA expense, will have new capabilities equivalent to some of the
capabilities envisioned for NCore multipollutant sites. After
consultations with State air quality planners and other data users, EPA
may adjust the goal of having 20 rural State-operated NCore stations,
if some of these CASTNET stations can achieve the same data objectives.
This would preserve State/local funding resources for other types of
monitoring. Alternatively, the CASTNET stations will contribute to a
more robust rural network with multipollutant capabilities.
2. Requirements for Operation of PM10-2.5 Stations
For PM10-2.5, EPA proposed a new minimum network
requirement based on metropolitan statistical area (MSA) population and
estimated PM10-2.5 design value. See 71 FR 2732-2736. Under
that proposal, only those MSAs that contained an urbanized area of at
least 100,000 persons were required to have one or more monitors. The
minimum network design requirements would not have included separate
requirements for multiple urbanized areas of 100,000 persons or more
within a single MSA. Where more than one MSA was part of a CSA, each
MSA was treated separately and was subject to individual requirements.
The EPA proposed that the actual or estimated PM10-2.5
design value (3-year average of 98th percentile 24-hour concentrations)
of a MSA, where one could be calculated, be used as a second factor to
increase the minimum number of monitors in MSAs with higher estimated
ambient coarse particle levels and to reduce requirements in MSAs with
lower estimated concentrations. The EPA developed an initial database
of estimated PM10-2.5 design values by analyzing
concentrations from existing collocated or nearly collocated
PM10 and PM2.5 monitors in each MSA and
identifying which pairs met the proposed siting criteria which
specified when a monitor was suitable for comparison to the proposed
PM10-2.5 NAAQS. Monitoring agencies were given the option of
proposing other procedures for calculating estimated
PM10-2.5 design values as a substitute for EPA-calculated
values.
The EPA's proposal would have required as many as five
PM10-2.5 monitors in MSAs with total population of more than
5 million with actual or estimated design values of greater than 80
percent of the proposed PM10-2.5 NAAQS, and no monitors in
MSAs under 1 million people with actual or estimated design values less
than 50 percent of that proposed NAAQS. The EPA estimated that the size
of the minimum required PM10-2.5 network would be
approximately 250 monitors based on these proposed requirements and the
most recent estimates of PM10-2.5 design values available at
the time of proposal. An additional review of urbanized area population
counts and estimated design values completed after proposal
subsequently reduced the
[[Page 61262]]
estimated size of the required PM10-2.5 network to
approximately 225 monitors (not counting PM10-2.5 monitors
at NCore stations) through the elimination of some MSAs where the
population of the urbanized area was found to be fewer than 100,000
persons, or where updated estimated design values decreased
sufficiently for monitoring requirements to drop into an adjoining
design value category with lower requirements.
As noted earlier, in addition to the minimum monitoring
requirements, EPA proposed a five-part test that would be used to
determine whether potential PM10-2.5 monitoring sites were
suitable for comparison to the proposed NAAQS. All five parts of the
site-suitability test were required to be met for data from required
monitors or non-required monitors to be compared to the proposed
PM10-2.5 NAAQS.
The EPA received extensive comments on all aspects of the
PM10-2.5 network design proposal including the minimum
monitoring requirements, five-part suitability test for
PM10-2.5 NAAQS comparability, and monitor placement
criteria. As summarized in section III.C.2 of the preamble for the
NAAQS revisions published elsewhere in this Federal Register, EPA is
not adopting a proposed PM10-2.5 NAAQS but instead will be
retaining the current 24-hour PM10 standard. Therefore, the
elements of the PM10-2.5 monitoring network design that were
proposed to implement an ambient network for the primary purpose of
determining NAAQS compliance are no longer required and are not
included in this final rule.
As described elsewhere in this notice, EPA is requiring
PM10-2.5 mass concentration and speciation monitoring as
part of the NCore network of multipollutant sites. These sites are
intended to track long-term trends for accountability of emissions
control programs and health assessments that contribute to ongoing
reviews of the NAAQS; support development of emissions control
strategies through air quality model evaluation and other observational
methods; support scientific studies ranging across technological,
health, and atmospheric process disciplines; and support ecosystem
assessments.
3. Requirements for Operation of PM2.5 Stations
The PM2.5 network includes over 1,200 FRM samplers at
approximately 900 sites that are operated to determine compliance with
the NAAQS; track trends, development, and accountability of emission
control programs; and provide data for health and ecosystem assessments
that contribute to periodic reviews of the NAAQS. More than 500
continuous PM2.5 monitors are operated to support public
reporting and forecasting of the AQI.
The EPA proposed to modify the network minimum requirements for
PM2.5 monitoring so that multiple urban monitors in the same
MSA or CSA are not required if they are redundant or are measuring
concentrations well below the NAAQS. See 71 FR 2741. EPA proposed to
base minimum monitoring requirements on PM2.5 concentrations
as represented by the design value of the area, and on the census
population of the CSA, or in cases where there is no CSA, the MSA.
Overall, this was expected to result in a lower number of required
sites (to satisfy minimum network design requirements); however, EPA
recommended that States continue to operate a high percentage of the
existing sites now utilizing FRM, but with FEM and ARM continuous
methods replacing the FRM monitors at many of the sites.\17\ Id.
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\17\ As explained earlier, an approved regional method (ARM) is
a PM2.5 method that has been approved specifically within
a State, local, or Tribal air monitoring network for purposes of
comparison to the National Ambient Air Quality Standards and to meet
other monitoring objectives. See section V.D.2 of this preamble.
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The EPA proposed to require that all sites counted by a State
towards meeting the minimum requirement for the number of
PM2.5 sites have an FRM, FEM, or ARM monitor. The EPA also
proposed that at least one-half of all the required PM2.5
sites be required to operate PM2.5 continuous monitors of
some type even if not an FEM or ARM.
As noted, EPA proposed to use design value and population as inputs
in deciding the minimum required number of PM2.5 monitoring
sites in each CSA/MSA. The EPA proposed these inputs so that monitoring
resources would be prioritized based on the number of people who may be
exposed to a problem and the level of exposure of that population.
Metropolitan areas with smaller populations would not be required to
perform as much monitoring as larger areas. If ambient air
concentrations as indicated by historical monitoring are low enough,
these smaller population areas would not have been required to continue
to perform any PM2.5 monitoring.
The proposed amendments also would have required fewer sites when
design values are well above (rather than near) the level of the NAAQS
to allow more flexibility in the use of monitoring resources in areas
where States and EPA are already confident of the severity and extent
of the PM2.5 problem and possibly in more need of other
types of data to address it.
We proposed to retain the current siting criteria for
PM2.5, which have an emphasis on population-oriented sites
at neighborhood scale and larger. See 71 FR 2741. In the proposal, EPA
stated that these current design criteria appeared to remain
appropriate for implementation of the proposed primary PM2.5
NAAQS. See 71 FR 2742. The proposal stated that the existing minimum
requirements effectively ensure that monitors are placed in locations
that appropriately reflect the community-oriented area-wide
concentrations levels used in the epidemiological studies that support
the proposed (and now final) lowering of the 24-hour NAAQS.
The EPA further proposed that background and transport sites remain
a required part of each State's network to support characterization of
regional transport and regional scale episodes of PM2.5. To
meet these requirements, IMPROVE samplers could be used even though
they would not be eligible for comparison to the PM2.5
NAAQS; these samplers are currently used in visibility monitoring
programs in Class I areas and national parks. Sites in other States
which are located at places that make them appropriate as background
and transport sites could also fulfill these minimum siting
requirements.
The preamble to the proposal also pointed out that in most MSAs,
the PM2.5 monitor recording the maximum annual
PM2.5 concentrations is the same as the monitor showing the
maximum 24-hour PM2.5 concentrations, suggesting that
generally it will be these common high-reading monitors that will
determine attainment/nonattainment for both the annual and 24-hour
PM2.5 NAAQS. 71 FR 2742. The preamble further noted that
where this is the case, supplemental monitors, such as continuous
PM2.5 monitors and PM2.5 speciation monitors,
should already be well located to help in understanding the causes of
the high PM2.5 concentrations. In a relatively small number
of cases, certain microscale PM2.5 monitors that have not
been eligible for comparison to the annual PM2.5 NAAQS and
that have been complying with the pre-existing 24-hour PM2.5
NAAQS of 65 [mu]g/m3, and therefore have no impact on
attainment status, may become more influential to attainment status
under the more stringent level of the then-proposed, now adopted 24-
hour PM2.5 standard. In these cases, EPA noted that States
may choose to move accompanying speciation and continuous monitors to
[[Page 61263]]
the new site of particular interest to get a better characterization of
PM2.5 at that location.
The EPA received a number of comments regarding the
PM2.5 network design. Several commenters expressed concern
regarding the provision to allow fewer required sites when monitored
PM2.5 concentrations are significantly above the
PM2.5 NAAQS. Commenters stated that allowing fewer sites
would be inadequate to demonstrate actual ambient air conditions. One
commenter stated that the provision had merit for long-term NAAQS such
as the annual average but not for short term standards. The commenter
pointed out that long term standards, where concentrations are averaged
out over a multiple year period, tend to provide relatively uniform
results even over a large geographical area; however, daily
observations are going to be more variable at a given site and from
site to site. Other commenters expressed concern that while they
appreciated the flexibility to redirect resources to speciation
sampling in areas with significantly high NAAQS design values, there
would still be a need for both speciation and FRM data. In these cases,
while the flexibility may be available, in practice it would be
difficult to shut down a monitor in an area that is significantly above
the NAAQS.
The EPA also received comments on using CSA as the definition for a
metropolitan area in which to apply the minimally required
PM2.5 monitoring network criteria. Commenters expressed
concern that the CSA was too large an area to apply minimum monitoring
requirements and that it may result in the loss of essential monitors
necessary to characterize the extent of nonattainment areas. In
addition, EPA received comments on the proposed requirement for the
PM2.5 monitoring network to provide for one-half the
required sites, rounded-up, to operate PM2.5 continuous
monitors. Commenters expressed concern that requiring PM2.5
continuous monitors, none of which at present meet FEM and/or ARM
performance criteria, may result in minimizing the impetus for
equipment manufacturers to further develop versions of these
technologies that would meet the FEM/ARM performance criteria. Some
commenters expressed concern that although PM2.5 continuous
monitors serve multiple monitoring objectives, which underscores the
need for their operation, requiring collocation with FRMs should not be
a requirement of all the sites since it places an unnecessary burden on
the States.
The EPA also received several comments regarding the location of
required PM2.5 monitoring sites, questioning EPA's proposal
to keep the siting requirements for PM2.5 monitors the same
despite the revision of the 24-hour NAAQS to a level at which
commenters asserted that violations of the 24-hour NAAQS may occur in
many middle scale or microscale locations not presently experiencing
violations of the current 24-hour NAAQS. The gist of the comments was
that more monitors should be deployed in middle and/or microscale
locations to find such violations. One commenter recommended that EPA
specifically require a monitoring organization to have at least one
microscale site in any area that is nonattainment or marginally
nonattainment for the 24-hour NAAQS.
In response to concerns about requiring fewer PM2.5
monitoring sites when monitored PM2.5 concentrations are
significantly above the NAAQS, EPA is not adopting the provision and
will instead provide two ranges of minimum monitoring requirements
depending on design value. As proposed, agencies with areas that are
significantly below the PM2.5 NAAQS (less than or equal to
85 percent of the annual and 24-hour PM2.5 NAAQS) will have
a lower minimum monitoring requirement. Areas that are within 15
percent of the NAAQS or above it will be required to operate more
PM2.5 monitoring sites (i.e., be required to deploy a
greater minimum number of monitors), relative to those at less than 85
percent of the NAAQS.
To address the comments concerning the most appropriate Census
Bureau definition in which to apply the PM2.5 minimum
monitoring requirements, EPA compared the current network to the number
of monitors that would be required using either CSA or MSA as the unit
for applying monitoring requirements. The results demonstrated that
using MSA ensures a few more required sites in areas that have multiple
MSAs making up a large CSA with high populations and large geographical
areas, without requiring new sites of less obvious priority in MSAs
that have smaller geographic coverage and population. Since the overall
goal of reducing redundant required sites in large metropolitan areas
can be met by using MSA as the unit for monitoring requirements, and
using MSA as the unit will also result in multiple MSAs with high
design values in the same CSA each having minimum monitoring
requirements to address spatial gradients in large areas, EPA is
adopting the MSA in as the geographic unit for applying the minimum
PM2.5 monitoring requirements. In a CSA, each MSA must meet
the MSA requirements separately.
In considering the comments on requiring one-half the required
PM2.5 sites to have continuous monitors, EPA notes that the
existing network of monitors is providing invaluable data for reporting
and forecasting of the AQI and in support of emergency situations such
as wildfires and natural disasters (e.g., Hurricane Katrina). Ensuring
a minimum network of these monitors is essential to informing the
public and policy makers on the quality of the air during air pollution
episodes. The technology utilized in the network continues to evolve as
agencies adopt the most suitable methods for use in their own network.
The EPA believes that as agencies continue to purchase the most optimal
equipment for their networks and as instrument manufacturers now will
have the opportunity to receive FEM or ARM approval for their
method(s), manufacturers will continue to develop better continuous
instruments. The EPA is therefore adopting the proposed requirement for
one-half the required PM2.5 sites to have continuous
monitors as proposed. However, to address the concern about whether
required continuous monitors need to be collocated with a matching
second continuous monitor, this final rule states that only one of all
the required PM2.5 continuous monitors in each MSA needs to
have such a collocated match. This will allow a minimal level of
performance characterization of the continuous monitors in each area
that they are operated. Additional PM2.5 continuous
monitors, when required, can either be collocated with FRMs or set up
at non-collocated sites to provide better spatial coverage of the MSA.
With regard to concerns expressed in comments about monitor siting
in light of the revised 24-hour PM2.5 NAAQS, EPA agrees that
the proposed change in the level of the primary 24-hour
PM2.5 NAAQS from 65 [mu]g/m3 to 35 [mu]g/
m3 raised the issue of whether any commensurate changes
would be needed in these requirements. The EPA has considered the
original requirements for PM2.5 network design promulgated
in 1997 and their rationale, how the PM2.5 network is
currently configured, what if any changes need to be made to this
network to make it consistent with the intended level of protection of
the lower 24-hour PM2.5 NAAQS in combination with the annual
PM2.5 NAAQS, and whether these or any changes should be
required by a general rule or developed on a case-by-case basis.
[[Page 61264]]
In specifying monitor siting criteria for the original
PM2.5 monitoring network in 1997, EPA noted that the annual
standard had been set based on epidemiology studies in which monitors
generally were representative of community-average exposures. The EPA
stated its expectations that the annual standard would generally be the
controlling standard in designating nonattainment areas and that
controlling emissions to reduce annual averages would lower both annual
and 24-hour PM2.5 concentrations across each annual NAAQS
nonattainment area. Accordingly, the PM2.5 network design
provisions in that final rule (62 FR 38833, July 18, 1997) and EPA's
subsequent negotiations with State/local monitoring agencies over
monitoring plans were largely but not solely directed at obtaining air
quality data reflecting community-wide exposures by placing monitors in
neighborhood and larger scales of representation.
Section 2.8 of appendix D of 40 CFR part 58 as promulgated in 1997
had only a few definite requirements regarding the siting of
PM2.5 monitors. Section 2.8.1.3 specified how many ``core''
monitors representing community-wide air quality were required based on
MSA population. For areas with populations of 500,000 or more, section
2.8.1.3.1(a) required that at least one core monitoring station must be
placed in a ``population-oriented'' area of expected maximum
concentration and (unless waived under section 2.8.1.3.4) at least one
core station in an area of poor air quality. Areas with populations
between 200,000 and 500,000 were required to operate at least one core
monitor. Section 2.8.1.3.4 strongly encouraged any State with an MSA
with only one required monitor (due to being fewer than 500,000 in
population or due to a waiver) to site it so it represented community-
oriented concentrations in areas of high average PM2.5
concentrations. Section 2.8.1.3.7 required core monitoring sites to
represent neighborhood or larger spatial scales. States could at their
initiative place additional monitors anywhere, but monitors in
relatively unique microscale, localized hot spot, or unique middle-
scale locations cannot be compared to the annual NAAQS, and any
monitoring site must be population-oriented to be compared to either
NAAQS. Part 58 App. D section 2.8.1.2.3.
In practice, the majority of PM2.5 monitors are deployed
at neighborhood scale and larger, meaning that they are located far
enough from large emission sources that they represent the fairly
uniform air quality across an area with dimensions of at least a few
kilometers and thus can be considered community-oriented. The existing
PM2.5 monitoring network continues to mostly be made up of
these population-oriented, community-oriented, neighborhood scale
monitoring sites. The EPA is presently aware of fewer than ten
PM2.5 monitors that are sited in relatively unique
population-oriented microscale areas, localized hot spots, or unique
population-oriented middle-scale areas. Such sites may have higher
concentrations than neighborhood scale sites on at least some days
because they may be close to and downwind of large emission sources,
but the number of people exposed to such concentrations is not large
relative to the surrounding communities.
The EPA believes the PM2.5 networks that were deployed
were, and the networks that are now operating currently are, consistent
with the intended level of protection of the annual PM2.5
NAAQS. Consistency or inconsistency with regard to the 24-hour
PM2.5 NAAQS has not been of practical significance until now
due to the near absence of violations of that standard. In the January
17, 2006, proposal notice, EPA said that it believed that the 1997
rule's design criteria remained appropriate for implementation of the
proposed primary PM2.5 NAAQS, including the lower 24-hour
NAAQS, because these requirements effectively ensured that monitors are
placed in locations that appropriately reflect the community-oriented
areawide concentration levels used in the epidemiological studies that
support the proposed lowering of the 24-hour PM2.5 NAAQS. 71
FR 2742. The EPA continues to believe this, noting that the monitors
used in the epidemiology studies underlying the 24-hour
PM2.5 NAAQS were sited similar to the majority of monitors
in the existing State/local networks.
No comments directly contradicted this assessment. While an
implication of the final monitoring rule provisions regarding siting of
PM2.5 monitors is that States may choose not to monitor
microenvironment or middle scale locations where some people are
exposed to 24-hour concentrations above the level of the 24-hour NAAQS,
such a result remains consistent with the community-oriented area-wide
level of protection on which the 24-hour PM2.5 NAAQS is
premised. Thus, EPA believes it is not appropriate to specifically
require any number of monitors to be placed in microenvironment or hot
spot locations as one commenter suggested.
On the other hand, States and EPA may agree as part of the annual
monitoring plan submission by the State and approval by the Regional
Administrator that in specific cases placement of new or relocated
monitors into microenvironment or middle scale locations is warranted
and consistent with the intended level of protection of the 24-hour
PM2.5 NAAQS. States may also propose, and EPA would be
inclined to approve, the placement of PM2.5 monitors in
populated areas too small to be subject to the requirements regarding
minimum numbers of monitors, if there is reason to believe
PM2.5 concentrations are of concern. Of particular interest
may be smaller cities and towns which presently lack any
PM2.5 monitor but which experience emission patterns such as
use of wood stoves and/or weather conditions such as inversions which
can create high short-term concentrations of PM2.5. States
also remain free to place SPM at any location, without need for EPA
review or approval.\18\
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\18\ The possible additional monitoring discussed in the text
above could be compared solely to the 24-hour PM2.5
NAAQS. As mentioned earlier, the 1997 rules provide that monitors
that are sited in relatively unique population-oriented microscale
areas, localized hot spots, or unique population-oriented middle-
scale areas, may not be compared to the annual PM2.5
NAAQS.
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The proposed rule text for 40 CFR 58, appendix D inadvertently
failed to include rule text on PM2.5 monitoring network
design criteria, found in existing appendix D section 2.8.1.2.3,
setting forth the requirements that: (1) The required monitors are
sited to represent community-wide air quality, (2) at least one
monitoring site is placed in a ``population-oriented'' area of expected
maximum concentration, and (3) at least one station is placed in an
area of poor air quality. Therefore, this final rule restores these
pre-existing requirements to appendix D. This final rule sets out these
criteria (in substantively identical but slightly redrafted form) in
appendix D section 4.7.1(b).
Also, as noted in the proposal and again above, some monitors that
have not measured high concentrations relative to the 1997 24-hour
NAAQS may become more influential to attainment status under the just
adopted, more stringent 24-hour NAAQS. In these cases, EPA encourages
States to consider adding or moving speciation and continuous monitors
to the newly influential site to get a better characterization of
PM2.5 concentrations and their causes at that location.
Finally, this final rule clarifies that IMPROVE monitors operated
by an
[[Page 61265]]
organization other than the State may be counted as satisfying the
State's obligation to operate background and transport monitoring sites
for PM2.5.
4. Requirements for Operation of PM10 Stations
PM10 monitors currently are deployed throughout the
country at about 1,200 sites, with most metropolitan areas already
operating more PM10 monitors than are required by current
monitoring requirements.
In the January 17, 2006, proposal notice, EPA proposed changes to
the PM10 requirements in coordination with new minimum
requirements for a PM10-2.5 monitoring network in support of
the proposed 24-hour PM10-2.5 NAAQS which would have
eventually replaced the PM10 NAAQS entirely. See 71 FR 2742.
As already explained, EPA is not finalizing the proposed NAAQS for
PM10-2.5 and instead is retaining the 24-hour
PM10 NAAQS for all parts of the U.S. This change has
necessitated a different approach for PM10 minimum
monitoring requirements from the one proposed.
Rather than revoking PM10 monitoring requirements, as
proposed, EPA believes that a robust nationwide monitoring network is
required to provide compliance data for the 24-hour PM10
NAAQS and to support other objectives including the assessment of long-
term trends, evaluations of the effectiveness of State and local coarse
particle control programs, and health effects research. The EPA has
therefore considered whether the existing National Air Monitoring
Station Criteria in Table 4 of appendix D of 40 CFR part 58, last
revisited in 1997, are still appropriate for these purposes. Because
these criteria have an urban focus by being based on MSAs, allow for
local considerations to be a factor in determining the actual required
number of stations, require more stations in larger MSAs and MSAs with
more evidence of poor PM10 air quality while also requiring
some stations even in clean MSAs of a certain size, and in the
aggregate will result in a required number of PM10 monitors
that is similar to the required numbers of ozone and PM2.5
monitors, EPA believes these criteria are appropriate. With regard to
the comparison to the required numbers of ozone and PM2.5
monitors, EPA has considered two directionally opposite factors.
PM10 is less spatially uniform than O3 or
PM2.5, suggesting the need for relatively more intensive
monitoring in areas with PM10 problems, but PM10
concentrations in most areas are below the PM10 NAAQS
(unlike for O3 and PM2.5) suggesting that fewer
monitors should be required overall for PM10. This final
rule therefore retains the current PM10 minimum network
requirements, except that these will no longer be called ``NAMS''
requirements.
The current PM10 minimum monitoring requirements in
section 3.7.7 of part 58 appendix D are based on MSA population and
three different ranges of ambient PM10 concentrations as
compared to the PM10 NAAQS. For MSAs in the lowest category
of ambient PM10 concentrations, those for which ambient
PM10 data show concentrations less than 80 percent of the
NAAQS, at least one monitor is required if the population of the MSA is
500,000 or greater. For MSAs in the highest category of ambient
PM10 concentrations, those for which ambient PM10
data show concentrations exceeding the NAAQS by 20 percent or more, at
least one monitor is required if the population of the MSAs is 100,000
persons or greater. These requirements list ranges of required
monitors, with the actual number of monitors to be determined by EPA
and States.
Based on PM10 ambient data for 2003-2005 and current
census population statistics, a minimum of between 200 and 500
PM10 FRM/FEM monitors will be required across all affected
MSAs. Over 800 PM10 monitors are in fact currently deployed
in these MSAs. About 400 other PM10 monitors currently
operate outside the boundary of any MSA. As stated in section III.B of
this preamble, EPA believes a reduction in the size of the existing
monitoring networks for certain pollutants, including PM10,
for which the large majority of monitors record no NAAQS violations, is
an appropriate way to free up resources for higher priority monitoring
objectives. These higher priority objectives could include meeting both
the new requirements in this final rule such as the NCore
multipollutant measurements and objectives defined by the local air
quality management program. The EPA notes that many PM10
monitors have been recording concentrations well below the 24-hour
PM10 NAAQS and thus are candidates for discontinuation at a
State's initiative. States may also choose to continue to operate
monitors in excess of the minimum requirements. To the extent that
States and Tribes are considering reducing the total number of
PM10 monitors deployed, EPA believes, consistent with the
basis for retaining the 24-hour PM10 standard, priority
should be given to maintaining monitors sited in urban and industrial
\19\ areas. States may of course choose to retain PM10
monitors that are recording concentrations below the PM10
NAAQS level to support monitoring objectives other than attainment/
nonattainment determinations, such as baseline monitoring for
prevention of significant deterioration permitting or public
information. The EPA expects to work with States to assess their
PM10 networks and help determine which of these monitors are
delivering valuable data and which monitors present disinvestment
opportunities. As should be evident, however, States may not reduce
their PM10 networks below the minimum requirements for
monitoring within MSAs given in 40 CFR part 58 appendix D.
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\19\ As used in the Staff Paper, the term ``mining sources'' is
intended to include all activities that encompass extraction and/or
mechanical handling of natural geologic crustal materials. In the
context of this rule making, neither mining nor agricultural sources
are included in the more general category of ``industrial sources.''
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In addition, if States and Tribes are considering deploying new
PM10 monitors, EPA recommends, again consistent with the
basis for retaining the 24-hour PM10 standard, that those
monitors be placed in areas where there are urban and/or industrial
sources of thoracic coarse particles. Furthermore, consistent with the
monitors used in studies that informed our decision on the level of the
standard (see section III.D of the final rule on the PM NAAQS published
elsewhere in today's Federal Register), EPA recommends that any new
PM10 monitors be placed in locations that are reflective of
community exposures at middle and neighborhood scales of
representation, and not in source-oriented hotspots that are not
population oriented.
The final rule omits two passages in section 4.6 (Particulate
Matter (PM10) Design Criteria) of 40 CFR 58, appendix D that
were included for providing context for the proposed rule. The omitted
passages are 4.6(b)(4) (Urban scale) and 4.6(b)(5) (Regional scale). As
explained below, these two passages are not consistent with EPA's
intention to preserve the substance of the 1997 monitoring rule
regarding scales of representativeness, while restructuring appendix D
to eliminate SLAMS versus NAMS distinctions and to make clearer which
requirements (and explanatory background and guidance) applied to each
individual pollutant. In appendix D of the 1997 monitoring rule,
section 2.8 (Particulate Matter Design Criteria for SLAMS) addressed
both PM2.5 and PM10, in some sentences referring
explicitly to PM2.5, PM10, or both, and in some
sentences referring only in general to particulate matter. In this
final rule, section 4.6 (Particulate Matter (PM10)
[[Page 61266]]
Design Criteria) addresses this subject matter for PM10,
while section 4.7 (Fine Particulate Matter (PM2.5) Design
Criteria) does so for PM2.5. In the proposed rule, for the
purpose of providing context, EPA included paragraphs on microscale,
middle scale, neighborhood scale, urban scale, and regional monitoring
scales in both section 4.6 and 4.7. However, EPA upon closer
consideration has determined that omitting the paragraphs on urban
scale and regional scale from section 4.6 is appropriate for
PM10, in terms of clarifying and preserving the effective
substance of the 1997 rule for PM10. The bases for reaching
this conclusion include the following: (1) The paragraphs concerning
these scales of representation in the 1997 appendix D (section 2.8.0.7
and 2.8.0.8) mention PM2.5 specifically but not
PM10, (2) the paragraph which precedes the five paragraphs
on the five scales (2.8.0.2) states that middle and neighborhood scales
are the most important scales for PM10, (3) section 2.8 in
the 1997 rule was titled as applying to SLAMS in particular but no
SLAMS monitors were specifically required at any spatial scale or
scales, (4) under section 3.7 (Particulate Matter Design Criteria for
NAMS) specific numbers of PM10 monitors were required but
without specification as to spatial scale, and (5) Table 6 of appendix
D in the 1997 rule indicates that only the micro, middle, and
neighborhood scales are ``required for NAMS.'' The EPA notes that in
the final rule, the same numbers of PM10 monitors are
required as in the 1997 rule, but they are not referred to as NAMS
monitors. The EPA notes that urban scale and regional scale are of
little, if any, relevance to PM10 monitoring, because of the
short transport distances for PM10, especially when emitted
near ground level. In contrast, because PM2.5 is a secondary
pollutant, large spatial scales are relevant because monitors in such
locations will reflect regional emissions trends and transport
patterns.
5. Requirements for Operation of Carbon Monoxide, Sulfur Dioxide,
Nitrogen Dioxide, and Lead Monitoring Stations
Criteria pollutant monitoring networks for the measurement of CO,
SO2, NO2, and Pb are primarily operated to
determine compliance with the NAAQS and to track trends and
accountability of emission control programs as part of a SIP. Because
these criteria pollutant concentrations are typically well below the
NAAQS, there is limited use for public reporting to the AQI.
The EPA proposed to revoke all minimum requirements for CO,
SO2, and NO2 monitoring networks, and reduce the
requirements for Pb. See 71 FR 27423. The proposal allowed for
reductions in ambient air monitoring for CO, SO2,
NO2, and Pb, particularly where measured levels are well
below the applicable NAAQS and air quality problems are not expected,
except in cases with ongoing regulatory requirements for monitoring
such as SIP or permit provisions. The EPA stated it would work with
States on a voluntary basis to make sure that at least some monitors
for these pollutants remain in place in each EPA region. Measurement of
CO, SO2, and NOy were also proposed as required
measurements at NCore sites. There may be little regulatory purpose for
keeping many other sites showing low concentrations, other than
specific State, local, or Tribal commitments to do so. However, in
limited cases, some of these monitors may be part of a long-term record
utilized in a health effects study. Under 40 CFR 58.11 of this final
rule, States must consider the effect of monitoring site closures on
data users other than the State itself, such as health effects studies.
The EPA expects State and local agencies to seek input on which
monitors are being used for health effects studies so they can give
this consideration. See also section IV.E.8 of this preamble.
6. Requirements for Operation of Ozone Stations
Ozone (O3) monitors currently are deployed throughout
the country at about 1,200 sites, with most metropolitan areas already
operating more O3 monitors than would be required by today's
action. The EPA does not anticipate or recommend significant changes to
the size of this network because O3 remains a pollutant with
measured levels near or above the NAAQS in many areas throughout the
country. However, this final rule should help to better prioritize
monitoring resources depending on the population and levels of
O3 in an area.
For O3, EPA proposed changing the minimum network
requirement from at least two sites in ``any urbanized area having a
population of more than 200,000'' to an approach that considers the
level of exposure to O3, as indicated by the design value,
and the census population of a metropolitan area. See 71 FR 2742. The
proposal stated that a CSA, or MSA if there is no CSA, with a
population of 10 million or more and a design value near the
O3 NAAQS would be required to operate at least four sites.
Smaller CSAs and MSAs as low as 350,000 people in population would be
required to operate as few as one site. An even smaller area would have
no required monitor, provided its design values (for example, from a
previously required monitor or a SPM) were sufficiently low. Taking the
same approach used in the proposed minimum requirements for
PM2.5 sites, EPA proposed that high-population areas with
measured ambient concentrations significantly above the NAAQS be
allowed to operate one less site than areas with measured ambient
concentrations near the NAAQS to allow flexibility of monitoring
resources in those areas.
The EPA received a number of comments on the proposed minimum
network requirements for O3. Similar to the comments
received on PM2.5, many commenters had concerns with
requiring only one site when an area is significantly above the NAAQS
and with defining the minimum monitoring requirements by CSA instead of
by a smaller level of a metropolitan area. For instance, several
commenters noted that by applying the minimum monitoring requirements
by CSA, agencies may not be required to deploy enough monitors to
characterize the within-MSA gradient needed to adequately characterize
O3 across a metropolitan area.
In response to concerns about allowing one less O3
monitoring site when a high-population area is significantly above the
NAAQS, EPA is not adopting this provision. This final rule instead
provides two values for the minimum required number of monitors
according to design value. Agencies with areas that are significantly
below the O3 NAAQS (less than or equal to 85 percent of the
O3 NAAQS) have the lower minimum monitoring requirement.
Areas that are within 15 percent of the NAAQS or above it have will be
required to operate more O3 monitoring sites.
To address the comments concerning the most appropriate Census
Bureau-defined area for which to apply the O3 minimum
monitoring requirements, EPA investigated the current network compared
with using either CSA or MSA as the basis for applying the minimum
network requirements. The results demonstrate that using MSA ensures a
few more sites in the small number of large CSAs that have high
populations and large geographical areas without unnecessarily
requiring new sites in the many areas that have smaller geographic
coverage and population. Since using MSA does not impose a significant
new burden on the States and makes it more likely that within-MSA
gradient characterization of
[[Page 61267]]
O3 will be characterized in high concentration areas, EPA is
adopting MSA as the appropriate unit of a metropolitan area to apply
the minimum O3 monitoring requirements. All other monitoring
requirements for O3 are adopted as proposed.
7. Requirements for Operation of Photochemical Assessment Monitoring
Stations
Section 182(c)(1) of the CAA required EPA to promulgate rules
requiring enhanced monitoring of O3, NO, and VOC in ozone
nonattainment areas classified as serious, severe, or extreme. On
February 12, 1993, EPA promulgated requirements for State and local
monitoring agencies to establish PAMS as part of their SIP monitoring
networks in ozone nonattainment areas classified as serious, severe, or
extreme. During 2001, EPA formed a workgroup consisting of EPA, State,
and local monitoring experts to evaluate the existing PAMS network. The
PAMS workgroup recommended that the existing PAMS requirements be
streamlined to allow for more individualized PAMS networks to suit the
specific data needs for a PAMS area.
The EPA proposed changes to the minimum PAMS monitoring
requirements in 40 CFR part 58 to implement the recommendations of the
PAMS workgroup. See 71 FR 2743. Specifically, EPA proposed the
following changes: The number of required PAMS sites would be reduced;
only one Type 2 site would be required per area regardless of
population and Type 4 sites would not be required; and only one Type 1
or one Type 3 site would be required per area. The requirements for
speciated VOC measurements would be reduced. Speciated VOC measurements
would only be required at Type 2 sites and one other site (either Type
1 or Type 3) per PAMS area. Carbonyl sampling would only be required in
areas classified as serious or above for the 8-hour O3
standard. Conventional NO2/NOX monitors would
only be required at Type 2 sites. High sensitivity NOy
monitors would be required at one site per PAMS area (either Type 1 or
Type 3). High sensitivity CO monitors would be required at Type 2
sites.
The EPA received comments on the proposed amended PAMS
requirements. Overall, the commenters supported the reduction in
minimum PAMS requirements which will allow for more individualized PAMS
networks and alternative enhanced O3 monitoring initiatives.
However, some commenters were concerned with the proposed requirement
for NOy monitoring at one Type 1 or one Type 3 site. Several
commenters stated that the PAMS NOy requirement is not
likely to be beneficial. They argued that NOy data in urban
areas are likely to be indistinguishable from NOX data, the
commercial NOy instrumentation is not yet fully developed,
NOy monitors are difficult to site properly, and that few
States have the modeling capability to employ NOy data.
The EPA disagrees with the commenters' statements that PAMS
NOy measurements will not be beneficial. As compared to
NOX measurements, NOy measurements provide a more
complete measurement of the available reactive nitrogen species
involved in the photochemical reactions that lead to O3
formation. One of the primary uses of NOy data is for
O3 modeling. However, O3 modeling is not the only
use for NOy data. Long-term measurements of NOy
provide the best indicator of the effectiveness of NOX
controls at reducing the reactive nitrogen compounds involved in
O3 formation. In addition, a relatively simple analysis of
the O3-to-NOy ratio, or VOC-to-NOy
ratio can be performed to identify if an area is ``NOX
limited'' or ``VOC limited'' which would indicate if additional
NOX controls would be more beneficial than additional VOC
controls.
Ideally, the NOX method should measure NO and
NO2, whereas NOy measurements include NO,
NO2, and other important reactive nitrogen species (referred
to here as NOz) which includes nitrous acids [nitric acid
(HNO3), and nitrous acid (HONO)], organic nitrates [peroxyl
acetyl nitrate (PAN), methyl peroxyl acetyl nitrate (MPAN), and peroxyl
propionyl nitrate, (PPN)], and particulate nitrates. However, recent
studies have shown that existing NOX monitors also measure
(and misreport as NO2) some NOz species. The NOy
method was developed as an extension of the NOX method to
accurately measure all reactive nitrogen compounds. Nonetheless, EPA
will allow for waivers of the NOy method (via an alternative
plan provided for under paragraph 5.3 of appendix D to part 53) in
areas where measured NOX is expected to provide virtually
the same data as NOy. This is largely expected to be in
areas with fresh oxides of nitrogen emissions until such time as the
NO2 method (and hence the NOX method) is
sufficiently improved that having separate measurements of
NOy and NOX provides more useful information than
the existing technology. The EPA has evaluated a number of commercially
available NOy monitors and has found them accurate and
reliable. As with many methods, EPA continues to evaluate improvements
to the method, but at this time EPA believes that the current method
(and commercially available instrumentation) provides data of
sufficient quality to meet the PAMS program objectives.
While proper siting of an NOy monitor (installing a 10
meter tower and meeting proper fetch characteristics) may be difficult
in some urban settings, EPA believes that NOy monitors can
be adequately sited at most PAMS areas. Nonetheless, if siting a
NOy monitor is not practicable in a given PAMS area, a State
may request an alternative plan, as allowed for under paragraph 5.3 of
appendix D to part 53, to allow monitoring of NOX instead of
monitoring for NOy.
After review and consideration of the comments received, EPA has
decided to finalize the revisions to the PAMS requirements as proposed.
F. Appendix E--Probe and Monitoring Path Siting Criteria for Ambient
Air Monitoring
The proposed revisions to this appendix consisted of minor
organizational changes and two technical changes to the siting criteria
affecting PM10-2.5 and O3 monitoring sites. See
71 FR 2748.
1. Vertical Placement of PM10-2.5 Samplers
Specific probe siting criteria were required to support the
proposed PM10-2.5 network. The EPA proposed vertical probe
placement requirements that limited microscale PM10-2.5
sites to an allowable height range of 2 to 7 meters and neighborhood
and large scale PM10-2.5 sites to a range of 2 to 15 meters.
These ranges were identical to the existing requirements for
PM10. The range for middle-scale PM10-2.5 sites
was limited to 2 to 7 meters which represented a change from
PM10 where 2 to 15 meters was the allowed vertical placement
range for middle-scale sites.
Several commenters supported the proposed PM10-2.5
middle-scale vertical requirement as being consistent with the
expectation that coarse particle concentrations nearest the breathing
zone would be important to measure in the assessment of exposure risk,
and that monitoring sites with more elevated inlets would be more
likely to miss localized concentrations where the public is exposed. By
contrast, other commenters raised concerns that the requirement would
result in the measurement of localized (microscale) near-ground
conditions not representative of a middle-scale sized area. Commenters
also noted the
[[Page 61268]]
importance of keeping identical inlet requirements for
PM10-2.5 and PM2.5 to maximize the benefits of
having collocated measurements at the same site.
Based on review of the comments, EPA is retaining the 2 to 7 meter
vertical requirement for middle-scale PM10-2.5 sites. This
requirement is consistent with current requirements for microscale PM
monitors but would require modifications for existing PM2.5
and PM10 monitors located between 8 and 15 meters above
ground that were intended for middle-scale PM10-2.5
measurement. The EPA does not expect this requirement to have a major
impact on monitoring networks since this final rule requires
PM10-2.5 monitoring only at NCore sites, and these sites
will typically represent neighborhood or larger scales. This final rule
retains the existing rule language that has the option for the Regional
Administrator to grant a waiver of siting criteria, providing
flexibility for States to document situations where useful data could
still be produced by monitors not meeting applicable requirements.
2. Ozone Monitor Setback Requirement From Roads
The EPA proposed an increase to the minimum permitted distance
between roadways and the inlet probes of neighborhood and urban scale
ozone and oxides of nitrogen sites to reduce the scavenging effects of
motor vehicle-related nitric oxide emissions. See 71 FR 2748.
Many commenters believed that the scavenging effects of oxides of
nitrogen on O3 levels in urban, populated areas was more of
an area-wide phenomena and would not be changed by moving a site a few
meters farther from the nearest roadway. The relative value of the
proposed change on the basis of the resource requirements necessary to
relocate sites not meeting the increased road setback requirements was
also questioned. Some support was noted for the application of the
increased roadway setback requirement to new sites as long as existing
ozone sites were ``grandfathered.''
The EPA acknowledges the logistical difficulty and expense of
moving existing sites to meet the increased setback requirement. To
achieve a balance between the goal of minimizing the interference of
roadway emissions on O3 and oxides of nitrogen monitor data
and to reduce the burden on affected monitoring organizations, EPA has
modified the increased roadway setback requirement to apply only to
newly established sites.
G. Sample Retention Requirements
During the regulatory development process, various governmental
agencies and health scientists indicated that archiving particulate
matter filters for FRM and FEM would be useful for later chemical
speciation analyses, mass analyses, or other analyses.
Current sample retention requirements apply specifically to
PM2.5 filters and require a minimum storage requirement of 1
year. The EPA proposed that retention requirements be expanded to
require archival of PM2.5, PM10-2.5, and
PM10c (low volume) filters for a period of 1 year after
collection. See 71 FR 2749.
Commenters were supportive of the proposed requirement. Some
commenters stated that the required filter retention period should be
longer than 1 year, with a range in suggested storage periods of
between 3 to 7 years. States provided examples of how filters archived
for longer than 1 year were subsequently analyzed to provide data
useful in the support of health studies, SIP work, or analysis of
exceptional events. Several commenters, while supportive of the
rationale for filter archival, preferred that the requirement not be
included in the regulation and instead left for voluntary monitoring
agency compliance. One commenter suggested that the requirement be
clarified to explicitly include retention of blank filters in addition
to exposed filters.
The EPA notes the support for the proposed sample retention
requirement and did not change that requirement in this final rule. As
stated in this final rule, States have the discretion to retain their
samples for longer than one year. The EPA supports such procedures,
recognizing that States will have different logistical constraints that
control the maximum length of time for which filters can be stored. The
EPA has clarified that the requirement applies to all such filters
referenced in 40 CFR 58.16(f), including exposed filters and blanks.
The EPA acknowledges the concern among some commenters that States
retain the right to determine the best use of archived filters. These
commenters stated that national considerations for filter analysis
should be considered a secondary priority to State needs. The EPA is
respectful of this issue, and expects to negotiate with States on the
scope of any request for archived filters intended for potentially
destructive analyses so that the request if compatible with other State
uses for the same type of filters.
The EPA did not propose a specific effective date for this
requirement in the monitoring rule and no commenters expressed
implementation concerns. Accordingly, this final rule includes an
effective date of January 1, 2007 for the sample retention requirement.
In the proposal, rule requirements regarding sample retention were
located in section 4.9 of appendix D, a section devoted to network
design criteria. The EPA believes that sample retention requirements
are more logically located in subpart B of part 58, which contains
provisions on data submittal. Accordingly, the title of 40 CFR 58.16
(``Data submittal'') has been renamed ``Data submittal and archiving
requirements'' and corresponding rule requirements on sample retention
have been moved to 40 CFR 58.16(f) of this final rule.
H. Deletion of Appendices B and F
This final rule removes and reserves appendix B of 40 CFR 58,
Quality Assurance Requirements for Prevention of Significant
Deterioration (PSD) Air Monitoring, and appendix F of 40 CFR part 58,
Annual SLAMS Air Quality Information, because both are obsolete.
The preamble to the proposed rule explicitly proposed to remove
appendix B because the quality assurance requirements for PSD
monitoring were proposed to be moved to appendix A, which this final
rule does. See 71 FR 2725. (The amendatory language at the end of the
January 17, 2006 proposal notice inadvertently did not list this
change.) No adverse comments were received on this change.
The January 17, 2006 notice did not explicitly address the
preservation or removal of appendix F, but its effective removal was
inherent in the proposed rule because no section of the proposed part
58 would continue to refer to appendix F. Similarly, the final part 58
does not refer to appendix F. Appendix F previously was referenced by
40 CFR 58.26 in subpart C, Annual state air monitoring report, now
deleted. Appendix F specified the required content, which was
extensive, of the annual report of summarized monitoring data. An
extensive annual report of summarized monitoring data is no longer
required in this final rule. New section, 40 CFR 58.16, Data submittal,
instead requires submission of individual data values. Summary
information on monitoring data is still required by 40 CFR 58.15,
Annual air monitoring data certification, for the sole purpose of
making it clear what data is within the scope of the required
certification letter. This final rule does not specify the exact
content of the
[[Page 61269]]
summary information required by 40 CFR 58.15 in order to provide more
flexibility and to accommodate possible evolution of the standardized
AQS reports which are the most convenient way for monitoring
organizations to provide this information.
VI. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
action is a ``significant regulatory action'' because it may raise
novel legal policy issues arising out of legal mandates, the
President's priorities, or the principles set forth in the Executive
Order. Accordingly, EPA submitted this action to the Office of
Management and Budget (OMB) for review under Executive Order 12866 and
any changes made in response to OMB recommendations have been
documented in the docket for this action.
B. Paperwork Reduction Act
The information collection requirements in this rule have been
submitted for approval to the Office of Management and Budget (OMB)
under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., OMB control
number 2060-0084. The information collection requirements are not
enforceable until OMB approves them.
The monitoring, recordkeeping, and reporting requirements in 40 CFR
parts 53 and 58 are specifically authorized by sections 110, 301(a),
and 319 of the Clean Air Act (CAA). All information submitted to EPA
pursuant to the monitoring, recordkeeping, and reporting requirements
for which a claim of confidentiality is made is safeguarded according
to Agency policies in 40 CFR part 2, subpart B.
The information collected under 40 CFR part 53 (e.g., test results,
monitoring records, instruction manual, and other associated
information) is needed to determine whether a candidate method intended
for use in determining attainment of the National Ambient Air Quality
Standards (NAAQS) in 40 CFR part 50 will meet the design, performance,
and/or comparability requirements for designation as a Federal
reference method (FRM) or Federal equivalent method (FEM). The final
amendments add requirements for PM10-2.5 FEM and FRM
determinations, Class II equivalent methods for PM10-2.5 and
Class III equivalent methods for PM2.5 and
PM10-2.5; reduce certain monitoring and data collection
requirements; and streamline EPA administrative requirements.
The incremental annual reporting and recordkeeping burden for this
collection of information under 40 CFR part 53 (averaged over the first
3 years of this ICR) for one additional respondent per year is
estimated to increase by a total of 2,774 labor hours per year with an
increase in costs of $32,000/year. The capital/startup costs for test
equipment and qualifying tests are estimated at $3,832 with operation
and maintenance costs of $27,772.
The information collected and reported under 40 CFR part 58 is
needed to determine compliance with the NAAQS, to characterize air
quality and associated health and ecosystems impacts, to develop
emission control strategies, and to measure progress for the air
pollution program. The amendments revise the technical requirements for
certain types of sites, add provisions for monitoring of
PM1010-2.5, and reduce certain monitoring requirements for
criteria pollutants. Monitoring agencies are required to submit annual
monitoring network plans, conduct network assessments every 5 years,
perform quality assurance activities, and, in certain instances,
establish NCore sites by January 1, 2011.
The annual average reporting burden for the collection under 40 CFR
part 58 (averaged over the first 3 years of this ICR) for 168
respondents is estimated to decrease by a total of 48,546 labor hours
per year with a decrease in costs of $6,151,494. State, local, and
Tribal entities are eligible for State assistance grants provided by
the Federal government under the CAA which can be used for monitors and
related activities.
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 purposes 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 in 40 CFR parts 53 and 58 are listed in 40 CFR part 9. When
these ICR are approved by OMB, EPA will publish a technical amendment
to 40 CFR part 9 in the Federal Register to display the OMB control
number for the approved information collection requirements contained
in this final rule.
C. Regulatory Flexibility Act
The EPA has determined that it is not necessary to prepare a
regulatory flexibility analysis in connection with these final rule
amendments.
For the purposes of assessing the impacts of the final amendments
on small entities, small entity is defined as: (1) A small business as
defined by the Small Business Administration's regulations at 13 CFR
121.201; (2) a government jurisdiction that is a government of a city,
county, town, school district or special district with a population of
less than 50,000; and (3) a small organization that is any not-for-
profit enterprise which is independently owned and operated and that is
not dominant in its field.
After considering the economic impacts of this final rule
amendments on small entities, EPA has concluded that this action will
not have a significant economic impact on a substantial number of small
entities. The final requirements in 40 CFR part 53 for an FEM
application are voluntary actions on the part of equipment
manufacturers to seek EPA approval for their candidate sampling
methods. The applications are evaluated according to the requirements
in 40 CFR part 53 and test data submitted by the manufacturers to EPA
to ensure that the candidate equivalent methods meet the same technical
standards as the FRM. The final amendments to 40 CFR part 58 will
reduce annual ambient air monitoring costs for State and local agencies
by approximately $6.2 million and 48,546 labor hours from present
levels. State and Tribal assistance grant funding provided by the
Federal government can be used to defray the costs of new or upgraded
monitors for the NCore networks.
D. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and Tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
[[Page 61270]]
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures to State, local, and Tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with this final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including Tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan. The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.
The EPA has determined that this final rule does not contain a
Federal mandate that may result in expenditures of $100 million or more
for State, local, and Tribal governments, in the aggregate, or the
private sector in any one year. The final amendments to 40 CFR part 58
will reduce annual ambient air monitoring costs for State and local
agencies by approximately $6.2 million and 48,546 labor hours from
present levels. Thus, these final amendments are not subject to the
requirements of sections 202 and 205 of the UMRA.
The EPA has determined that this final rule contains no regulatory
requirements that might significantly or uniquely affect small
governments. Small governments that may be affected by the final
amendments are already meeting similar requirements under the existing
rules, and the final amendments will substantially reduce the costs of
the existing rules. Therefore, this final rule is not subject to the
requirements of section 203 of the UMRA.
E. Executive Order 13132: Federalism
Executive Order 13132 (64 FR 43255, August 10, 1999), requires EPA
to develop an accountable process to ensure ``meaningful and timely
input by State and local officials in the development of regulatory
policies that have federalism implications.'' ``Policies that have
federalism implications'' is defined in the Executive Order to include
regulations that have ``substantial direct effects on the States, on
the relationship between the national government and the States, or on
the distribution of power and responsibilities among the various levels
of government.''
This final rule does not have federalism implications because it
will not have substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132. Thus, Executive
Order 13132 does not apply to this final rule.
Although section 6 of the Executive Order does not apply to this
final rule, EPA did consult with representatives of State and local
governments early in the process of developing this proposed rule. In
2001, EPA organized a National Monitoring Steering Committee (NMSC) to
provide oversight and guidance in reviewing the existing air pollution
monitoring program and in developing a comprehensive national ambient
air monitoring strategy. The NMSC membership includes representatives
from EPA, State and local agencies, State and Territorial Air Pollution
Program Administrators/Association of Local Air Pollution Control
Officials (STAPPA/ALAPCO), and Tribal governments to reflect the
partnership between EPA and governmental agencies that collect and use
ambient air data. The NMSC formed workgroups to address quality
assurance, technology, and regulatory review of the draft ambient air
monitoring strategy (NAAMS). These workgroups met several times by
phone and at least once in a face-to-face workshop to develop specific
recommendations for improving the ambient air monitoring program. A
record of the Steering Committee members, workgroup members, and
workshop are available on the Web at: http://www.epa.gov/ttn/amtic/monitor.html. The EPA also met with State, local, and Tribal government
representatives to discuss their comments on the proposed amendments
and suggestions for resolving issues.
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
Executive Order 13175, entitled ``Consultation and Coordination
with Indian Tribal Governments'' (65 FR 67249, November 9, 2000),
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by tribal officials in the development of regulatory
policies that have tribal implications.'' This final rule does not have
tribal implications, as specified in Executive Order 13175. The final
amendments will not directly apply to Tribal governments. However, a
Tribal government may elect to conduct ambient air monitoring and
report the data to AQS. Since it is possible that tribal governments
may choose to establish and operate NCore sites as part of the national
monitoring program, EPA consulted with Tribal officials early in the
process of developing the proposed rule to permit them to have
meaningful and timely input into its development and after proposal to
discuss their comments and concerns. As discussed in section VI.E of
this preamble, tribal agencies were represented on both the NMSSC and
the workgroups that developed the NAAMS document and proposed
monitoring requirements. Tribal monitoring programs were represented on
both the Quality Assurance and Technology work groups. Participation
was also open to tribal monitoring programs on the regulatory review
workgroup.
G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks
Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any
rule that: (1) Is determined to be ``economically significant'' as
defined under Executive Order 12866, and (2) concerns an environmental
health or safety risk that EPA has reason to believe may have a
disproportionate effect on children. If the regulatory action meets
both criteria, EPA must evaluate the environmental health or safety
effects of the planned rule on children, and explain why the planned
regulation is preferable to other potentially effective and reasonably
feasible alternatives considered by EPA.
The EPA interprets Executive Order 13045 as applying only to those
regulatory actions that are based on health or safety risks, such that
the analysis required under section 5-501 of the Order has the
potential to influence the regulation. This final rule is not subject
to Executive Order 13045 because, while it is based on the need for
monitoring data to characterize risk,
[[Page 61271]]
this final monitoring rule itself does not establish an environmental
standard intended to mitigate health or safety risks.
H. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
Executive Order 12898 (58 FR 7629, February 11, 1994) requires that
each Federal agency make achieving environmental justice part of its
mission by identifying and addressing, as appropriate,
disproportionately high and adverse human health or environmental
effects of its programs, policies, and activities on minorities and
low-income populations. These requirements have been addressed to the
extent practicable in the Regulatory Impact Analysis (RIA) for the
final revisions to the NAAQS for particulate matter.
I. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use
This final rule is not a ``significant energy action'' as defined
in Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution or Use'' (66 FR 28355,
May 22, 2001) because it is not likely to have a significant adverse
effect on the supply, distribution, or use of energy. No significant
change in the use of energy is expected because the total number of
monitors for ambient air quality measurements will not increase above
present levels. Further, EPA has concluded that this final rule is not
likely to have any adverse energy effects.
J. National Technology Transfer Advancement Act
Section 12(d) of the National Technology Transfer Advancement Act
of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies. The NTTAA directs EPA to provide
Congress, through OMB, explanations when EPA decides not to use
available and applicable voluntary consensus standards.
The final amendments involve environmental monitoring and
measurement. Ambient air concentrations of PM2.5 are
currently measured by the Federal reference method in 40 CFR part 50,
appendix L (Reference Method for the Determination of Fine Particulate
as PM2.5 in the Atmosphere) or by FRM or FEM that meet the
requirements in 40 CFR part 53. Ambient air concentrations of
PM10-2.5 will be measured by the final FRM in 40 CFR part
50, appendix O (Reference Method for the Determination of Coarse
Particulate Matter as PM10-2.5 in the Atmosphere) published
elsewhere in this Federal Register or by an FRM or FEM that meets the
requirements in 40 CFR part 53. As discussed in section IV.B of this
preamble, the final FRM for PM10-2.5 is similar to the
existing methods for PM2.5 and PM10.
Procedures are included in this final rule that allow for approval
of an FEM for PM10-2.5 that is similar to the final FRM. Any
method that meets the performance criteria for a candidate equivalent
method may be approved for use as an FRM or FEM.
This approach is consistent with EPA's Performance-Based
Measurement System (PBMS). The PBMS approach is intended to be more
flexible and cost effective for the regulated community; it is also
intended to encourage innovation in analytical technology and improved
data quality. The EPA is not precluding the use of any method, whether
it constitutes a voluntary consensus standard or not, as long as it
meets the specified performance criteria.
K. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801, et seq., as added by
the Small Business Regulatory Enforcement Fairness Act of 1996,
generally provides that before a rule may take effect, the agency
promulgating the rule must submit a rule report, which includes a copy
of the rule, to each House of Congress and to the Comptroller General
of the United States. The EPA will submit a report containing the final
amendments and other required information to the U.S. Senate, the U.S.
House of Representatives, and the Comptroller General of the United
States prior to publication of the final amendments in the Federal
Register. A major rule cannot take effect until 60 days after it is
published in the Federal Register. This action is not a ``major rule''
as defined by 5 U.S.C. 804(2). This final rule will not have an annual
effect on the economy of $100 million or more, will not result in a
major increase in costs or prices for State or local agencies, and will
not affect competition with foreign-based enterprises in domestic and
export markets. The final amendments will be effective on December 18,
2006. The final amendments will be effective 60 days after publication
in the Federal Register to be consistent with the effective date of the
revised NAAQS for PM published elsewhere in this Federal Register.
Revisions to Ambient Air Monitoring Regulations.
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: September 27, 2006.
Stephen L. Johnson,
Administrator.
0
For the reasons set out in the preamble, title 40, chapter I, parts 53
and 58 of the Code of Federal Regulations are amended as follows:
PART 53--[AMENDED]
0
1. The authority citation for part 53 continues to read as follows:
Authority: Section 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.
Subpart A--[Amended]
0
2. Sections 53.1 through 53.5 are revised to read as follows:
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.
Additive and multiplicative bias means the linear regression
intercept and slope of a linear plot fitted to corresponding candidate
and reference method mean measurement data pairs.
Administrator means the Administrator of the Environmental
Protection Agency (EPA) or his or her authorized representative.
Agency means the Environmental Protection Agency.
Applicant means a person or entity who submits an application for a
Federal reference method or Federal 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),
[[Page 61272]]
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
Federal reference method determination or a Federal 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 or PM10-2.5 which is based on a sampler
that is very similar to the sampler specified for reference methods in
appendix L or appendix O (as applicable) of part 50 of this chapter,
with only minor deviations or modifications, as determined by EPA.
Class II equivalent method means an equivalent method for
PM2.5 or PM10-2.5 that utilizes a
PM2.5 sampler or PM10-2.5 sampler in which
integrated PM2.5 samples or PM10-2.5 samples are
obtained from the atmosphere by filtration and 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 or appendix O (as
applicable) of part 50 of this chapter, as determined by EPA.
Class III equivalent method means an equivalent method for
PM2.5 or PM10-2.5 that is an analyzer capable of
providing PM2.5 or PM10-2.5 ambient air
measurements representative of one-hour or less integrated
PM2.5 or PM10-2.5 concentrations as well as 24-
hour measurements determined as, or equivalent to, the mean of 24 one-
hour consecutive measurements.
CO means carbon monoxide.
Collocated means two or more air samplers, analyzers, or other
instruments that are operated simultaneously 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.
Federal equivalent method (FEM) 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.
Federal reference method (FRM) 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.
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; or
(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
Federal reference method and Federal 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 thereof, 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 automatically collecting a series of sequential samples.
NO means nitrogen oxide.
NO2 means nitrogen dioxide.
NOX means oxides of nitrogen and is defined as the sum of the
concentrations of NO2 and NO.
O3 means ozone.
Operated simultaneously means that two or more collocated samplers
or analyzers are operated concurrently with no significant difference
in the start time, stop time, and duration of the sampling or
measurement period.
Pb means lead.
PM means PM10, PM10C, PM2.5,
PM10-2.5, or particulate matter of unspecified size range.
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 appendix L of part 50 of this chapter and designated in
accordance with part 53 of this chapter, by an equivalent method
designated in accordance with part 53 of this chapter, or by an
approved regional method designated in accordance with appendix C to
this part.
PM10 means particulate matter with an aerodynamic diameter less
than or equal to a nominal 10 micrometers as measured by a reference
method based on appendix J of part 50 of this chapter and designated in
accordance with this part or by an equivalent method designated in
accordance with this part.
PM10C means particulate matter with an aerodynamic diameter less
than or equal to a nominal 10 micrometers as measured by a reference
method based on appendix O of part 50 of this chapter and designated in
accordance with this part or by an equivalent method designated in
accordance with this part.
PM10-2.5 means particulate matter with an aerodynamic diameter less
than or equal to a nominal 10 micrometers and greater than a nominal
2.5 micrometers as measured by a reference method based on appendix O
to part 50 of this chapter and designated in accordance with this part
or by an equivalent method designated in accordance with this part.
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.
PM10C sampler means a PM10 sampler that meets the
special requirements for a PM10C sampler that is part of a
PM10-2.5 reference method sampler, as specified in appendix
O to part 50 of this chapter, or a PM10 sampler that is part
of a PM10-2.5 sampler that has been designated as an
equivalent method for PM10-2.5.
[[Page 61273]]
PM10-2.5 sampler means a sampler, or a collocated pair of samplers,
associated with a manual method for measuring PM10-2.5 and
designed to collect either PM10-2.5 directly or
PM10C and PM2.5 separately and simultaneously
from concurrent ambient air samples, but lacking the ability to
automatically analyze or measure the collected sample(s) to determine
the mass concentrations of PM10-2.5 in the sampled air.
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.
SO2 means sulfur dioxide.
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, PM2.5
sampler, or PM10-2.5 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
Federal reference method or a Federal equivalent method for purposes
other than resale.
Sec. 53.2 General requirements for a reference method determination.
The following general requirements for a Federal reference method
(FRM) determination are summarized in table A-1 of this subpart.
(a) Manual methods--(1) Sulfur dioxide (SO2) and lead. For
measuring SO2 and lead, appendices A and G of part 50 of
this chapter specify unique manual FRM for measuring these pollutants.
Except as provided in Sec. 53.16, other manual methods for
SO2 and lead will not be considered for FRM determinations
under this part.
(2) PM10. A FRM 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 this subpart A and subpart D of this part.
(3) PM2.5. A FRM 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 this subpart A and subpart E of this part.
Further, FRM samplers must be manufactured in an ISO 9001-registered
facility, as defined in Sec. 53.1 and as set forth in Sec. 53.51.
(4) PM10-2.5. A FRM for measuring PM10-2.5 must be a
manual method that meets all requirements specified in appendix O of
part 50 of this chapter and must include PM10C and
PM2.5 samplers that have been shown in accordance with this
part to meet the applicable requirements specified in this subpart A
and subpart E of this part. Further, PM10-2.5 FRM samplers
must be manufactured in an ISO 9001-registered facility, as defined in
Sec. 53.1 and as set forth in Sec. 53.51.
(b) Automated methods. An automated FRM for measuring CO,
O3, or 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 this subpart A and subpart B
of this part.
Sec. 53.3 General requirements for an equivalent method
determination.
(a) Manual methods. A manual Federal equivalent method (FEM) must
have been shown in accordance with this part to satisfy the applicable
requirements specified in this subpart A and subpart C of this part. In
addition, a PM sampler associated with a manual method for
PM10, PM2.5, or PM10-2.5 must have
been shown in accordance with this part to satisfy the following
additional requirements, as applicable:
(1) PM10. A PM10 sampler associated with a manual method
for PM10 must satisfy the requirements of subpart D of this
part.
(2) PM2.5 Class I. A PM2.5 Class I FEM sampler must also
satisfy all requirements of subpart E of this part, which shall include
appropriate demonstration that each and every deviation or modification
from the FRM sampler specifications does not significantly alter the
performance of the sampler.
(3) PM2.5 Class II. (i) A PM2.5 Class II FEM sampler
must also satisfy the applicable requirements of subparts E and F of
this part or the alternative requirements in paragraph (a)(3)(ii) of
this section.
(ii) In lieu of the applicable requirements specified for Class II
PM2.5 methods in subparts C and F of this part, a Class II
PM2.5 FEM sampler may alternatively meet the applicable
requirements in paragraphs (b)(3)(i) through (iii) of this section and
the testing, performance, and comparability requirements specified for
Class III equivalent methods for PM2.5 in subpart C of this
part.
(4) PM10-2.5 Class I. A PM10-2.5 Class I FEM sampler
must also satisfy the applicable requirements of subpart E of this part
(there are no additional requirements specifically for Class I
PM10-2.5 methods in subpart C of this part).
(5) PM10-2.5 Class II. (i) A PM10-2.5 Class II FEM
sampler must also satisfy the applicable requirements of subpart C of
this part and also the applicable requirements and provisions of
paragraphs (b)(3)(i) through (iii) of this section, or the alternative
requirements in paragraph (a)(5)(ii) of this section.
(ii) In lieu of the applicable requirements specified for Class II
PM10-2.5 methods in subpart C of this part and in paragraph
(b)(3)(iii) of this section, a Class II PM10-2.5 FEM sampler
may alternatively meet the applicable requirements in paragraphs
(b)(3)(i) and (ii) of this section and the testing, performance, and
comparability requirements specified for Class III FEMs for
PM10-2.5 in subpart C of this part.
(6) ISO 9001. All designated FEMs for PM2.5 or
PM10-2.5 must be manufactured in an ISO 9001-registered
facility, as defined in Sec. 53.1 and as set forth in Sec. 53.51.
(b) Automated methods. All types of automated FEMs must have been
shown in accordance with this part to satisfy the applicable
requirements specified in this subpart A and subpart C of this part. In
addition, an automated FEM must have been shown in accordance with this
part to satisfy the following additional requirements, as applicable:
(1) An automated FEM for pollutants other than PM must be shown in
accordance with this part to satisfy the applicable requirements
specified in subpart B of this part.
(2) An automated FEM for PM10 must be shown in
accordance with this part to satisfy the applicable requirements of
subpart D of this part.
(3) A Class III automated FEM for PM2.5 or
PM10-2.5 must be shown in accordance with this part to
satisfy the requirements in paragraphs (b)(3)(i) through (iii) of this
section, as applicable.
(i) All pertinent requirements of 40 CFR part 50, appendix L,
including sampling height, range of operational conditions, ambient
temperature and pressure sensors, outdoor enclosure, electrical power
supply, control devices and operator interfaces, data output port,
operation/instruction manual, data output and reporting requirements,
and any other requirements that would be reasonably applicable to the
method, unless adequate (as determined by the Administrator) rationale
can be
[[Page 61274]]
provided to support the contention that a particular requirement does
not or should not be applicable to the particular candidate method.
(ii) All pertinent tests and requirements of subpart E of this
part, such as instrument manufacturing quality control; final assembly
and inspection; manufacturer's audit checklists; leak checks; flow rate
accuracy, measurement accuracy, and flow rate cut-off; operation
following power interruptions; effect of variations in power line
voltage, ambient temperature and ambient pressure; and aerosol
transport; unless adequate (as determined by the Administrator)
rationale can be provided to support the contention that a particular
test or requirement does not or should not be applicable to the
particular candidate method.
(iii) Candidate methods shall be tested for and meet any
performance requirements, such as inlet aspiration, particle size
separation or selection characteristics, change in particle separation
or selection characteristics due to loading or other operational
conditions, or effects of surface exposure and particle volatility,
determined by the Administrator to be necessary based on the nature,
design, and specifics of the candidate method and the extent to which
it deviates from the design and performance characteristics of the
reference method. These performance requirements and the specific
test(s) for them will be determined by Administrator for each specific
candidate method or type of candidate method and may be similar to or
based on corresponding tests and requirements set forth in subpart F of
this part or may be special requirements and tests tailored by the
Administrator to the specific nature, design, and operational
characteristics of the candidate method. For example, a candidate
method with an inlet design deviating substantially from the design of
the reference method inlet would likely be subject to an inlet
aspiration test similar to that set forth in Sec. 53.63. Similarly, a
candidate method having an inertial fractionation system substantially
different from that of the reference method would likely be subject to
a static fractionation test and a loading test similar to those set
forth in Sec. Sec. 53.64 and 53.65, respectively. A candidate method
with more extensive or profound deviations from the design and function
of the reference method may be subject to other tests, full wind-tunnel
tests similar to those described in Sec. 53.62, or to special tests
adapted or developed individually to accommodate the specific type of
measurement or operation of the candidate method.
(4) All designated FEM for PM2.5 or PM10-2.5
must be manufactured in an ISO 9001-registered facility, as defined in
Sec. 53.1 and as set forth in Sec. 53.51.
Sec. 53.4 Applications for reference or equivalent method
determinations.
(a) Applications for FRM or FEM determinations shall be submitted
in duplicate to: Director, National Exposure Research Laboratory,
Reference and Equivalent Method Program (MD-D205-03), U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711 (Commercial delivery address: 4930 Old Page Road, Durham, North
Carolina 27703).
(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 or PM10-2.5 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 descriptions of 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 any applicable appendix 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 (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 part
B, sections 3.3.1 (paragraph 1) and 3.5.1 and part C, section 4.6 of
reference 2 of appendix A of this subpart; and in paragraphs 1 through
3 of section 4.8 (Records) of reference 5 of appendix A of this
subpart. Salient requirements
[[Page 61275]]
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, PM2.5, and PM10-2.5 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 and PM10-2.5 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 and PM10-2.5 the warranty program must
ensure that the required specifications (see Table A-1 to 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 reference 1 of 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 reference 1 of appendix A of this subpart
requires documented procedures for control of nonconforming product,
including review and acceptable alternatives for disposition; section
4.14 in reference 1 of 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 and Class II or Class III equivalent methods for
PM10-2.5, the applicant, if requested by EPA, 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 Director,
National Exposure Research Laboratory, Reference and Equivalent Method
Program (MD-D205-03), U.S. Environmental Protection Agency, 4930 Old
Page Road, Durham, North Carolina 27703, 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. The 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 FRM or FEM determination, the
Administrator will, 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
[[Page 61276]]
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).
3. Sections 53.8 and 53.9 are revised to read as follows:
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 FRM
or FEM (as applicable) by and upon publication of a notice of the
designation in the Federal Register.
(b) Upon designation, a notice indicating that the method has been
designated as a FRM or FEM shall be sent to the applicant.
(c) The Administrator will maintain a current list of methods
designated as FRM or FEM 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 and may be available via the Internet or other sources.
Sec. 53.9 Conditions of designation.
Designation of a candidate method as a FRM or FEM 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 FRM or FEM shall be
accompanied by a copy of the manual referred to in Sec. 53.4(b)(3)
when delivered to any ultimate purchaser, and an electronic copy of the
manual suitable for incorporating into user-specific standard operating
procedure documents shall be readily available to any users.
(b) Any method offered for sale as a FRM or FEM shall generate no
unreasonable hazard to operators or to the environment during normal
use or when malfunctioning.
(c) Any analyzer, PM10 sampler, PM2.5
sampler, or PM10-2.5 sampler offered for sale as part of a
FRM or FEM 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, PM2.5
sampler, or PM10-2.5 sampler offered for sale as a FRM or
FEM shall bear a prominent, permanently affixed label or sticker
indicating that the analyzer or sampler has been designated by EPA as a
FRM or FEM (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 FRM or FEM 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 FRM or FEM.
(f) An applicant who offers analyzers, PM10 samplers,
PM2.5 samplers, or PM10-2.5 samplers for sale as
FRM or FEMs 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 FRM or FEM
designation applicable to such an analyzer or sampler, the applicant
shall notify all ultimate purchasers of the analyzer or 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,
PM2.5 sampler, or PM10-2.5 sampler that has been
designated as a FRM or FEM, 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 or sampler or has applied for and
received notice under Sec. 53.8(b) of a new FRM or FEM determination
for the modified analyzer or sampler.
(h) An applicant who has offered PM2.5 or
PM10-2.5 samplers or analyzers for sale as part of a FRM or
FEM 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 FRM or FEM
designation under Sec. 53.11.
(i) An applicant who has offered PM2.5 or
PM10-2.5 samplers or analyzers for sale as part of a FRM or
FEM 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.
4. Table A-1 to subpart A of part 53 is revised to read as follows:
Table A-1 to Subpart A of Part 53.--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...................
Equivalent......... Manual............. .................... [check] .......... [check]
[[Page 61277]]
Automated.......... .................... [check] [check] [check]
CO.................. Reference.......... Automated.......... C................... [check] [check]
Equivalent......... Manual............. .................... [check] .......... [check]
Automated.......... .................... [check] [check] [check]
O3.................. Reference.......... Automated.......... D................... [check] [check]
Equivalent......... Manual............. .................... [check] .......... [check]
Automated.......... .................... [check] [check] [check]
NO2................. Reference.......... Automated.......... F................... [check] [check]
Equivalent......... Manual............. .................... [check] .......... [check]
Automated.......... .................... [check] [check] [check]
Pb.................. Reference.......... Manual............. G................... ..........
Equivalent......... Manual............. .................... [check] .......... [check]
PM10................ Reference.......... Manual............. J................... [check] .......... ......... [check]
Equivalent......... Manual............. .................... [check] .......... [check] [check]
Automated.......... .................... [check] .......... [check] [check]
PM2.5............... Reference.......... Manual............. L................... [check] .......... ......... ......... [check]
Equivalent Class I. Manual............. L................... [check] .......... [check] ......... [check]
Equivalent Class II Manual............. L1.................. [check] .......... [check]2 ......... [check] [check]1,
2
Equivalent Class Automated.......... L1.................. [check] .......... [check] ......... [check]1 [check]1
III.
PM10 2.5............ Reference.......... Manual............. O2.................. [check] .......... ......... ......... [check]
Equivalent Class I. Manual............. O2.................. [check] .......... ......... ......... [check]
Equivalent Class II Manual............. O2.................. [check] .......... [check]2 ......... [check]1 [check]1,
2
Equivalent Class Automated.......... L1,O1, 2............ [check] .......... [check] ......... [check]1 [check]1
III.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Some requirements may apply, based on the nature of each particular candidate method, as determined by the Administrator.
\2\ Alternative Class III requirements may be substituted.
[[Page 61278]]
0
5. Paragraphs (1), (2), and (6) of appendix A to subpart A of part 53
are revised to read as follows:
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, P.O. Box 3005, Milwaukee, WI 53202 (http://qualitypress.asq.org).
(2) American National Standard Quality Systems for Environmental
Data and Technology Programs--Requirements with guidance for use,
ANSI/ASQC E4-2004. Available from American Society for Quality P.O.
Box 3005, Milwaukee, WI 53202 (http://qualitypress.asq.org).
* * * * *
(6) Quality Assurance Guidance Document 2.12. Monitoring
PM2.5 in Ambient Air Using Designated Reference or Class
I Equivalent Methods. U.S. EPA, National Exposure Research
Laboratory, Research Triangle Park, NC, November 1998 or later
edition. Currently available at http://www.epa.gov/ttn/amtic/pmqainf.html.
0
6. Subpart C is revised to read as follows:
Sec.
Subpart C--Procedures for Determining Comparability Between Candidate
Methods and Reference Methods
53.30 General provisions.
53.31 [Reserved]
53.32 Test procedures for methods for SO2, CO,
O3, and NO2.
53.33 Test procedure for methods for Pb.
53.34 Test procedures for methods for PM10 and Class I
methods for PM2.5.
53.35 Test procedures for Class II and Class III methods for
PM2.5 and PM10-2.5.
Tables to Subpart C of Part 53
Table C-1 to Subpart C of Part 53--Test Concentration Ranges, Number of
Measurements Required, and Maximum Discrepancy Specification
Table C-2 to Subpart C of Part 53--Sequence of Test Measurements
Table C-3 to Subpart C of Part 53--Test Specifications for Pb Methods
Table C-4 to Subpart C of Part 53--Test Specifications for
PM10, PM2.5, and PM10-2.5 Candidate
Equivalent Methods
Table C-5 to Subpart C of Part 53--Summary of Comparability Field
Testing Campaign Site and Seasonal Requirements for Class II and III
FEMs for PM10-2.5 and PM2.5
Figures to Subpart C of Part 53
Figure C-1 to Subpart C of Part 53--Suggested Format for Reporting Test
Results for Methods for SO2, CO, O3,
NO2
Figure C-2 to Subpart C of Part 53--Illustration of the Slope and
Intercept Limits for Class II and Class III PM2.5 Candidate
Equivalent Methods
Figure C-3 to Subpart C of Part 53--Illustration of the Slope and
Intercept Limits for Class II and Class III PM10-2.5
Candidate Equivalent Methods
Figure C-4 to Subpart C of Part 53--Illustration of the Minimum Limits
for Correlation Coefficient for PM2.5 and
PM10-2.5 Class II and III Methods
Appendix to Subpart C of Part 53
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. Minor deviations in testing requirements
and acceptance requirements set forth in this subpart, in connection
with any documented extenuating circumstances, may be determined by the
Administrator to be acceptable, at the discretion of the Administrator.
(b) Selection of test sites. (1) Each test site shall be in an area
which can be shown to have at least moderate concentrations of various
pollutants. Each site shall be clearly identified and shall be
justified as an appropriate test site with suitable supporting evidence
such as a description of the surrounding area, characterization of the
sources and pollutants typical in the area, maps, population density
data, vehicular traffic data, emission inventories, pollutant
measurements from previous years, concurrent pollutant measurements,
meteorological data, and other information useful in supporting the
suitability of the site for the comparison test or tests.
(2) If approval of one or more proposed test sites is desired prior
to conducting the tests, a written request for approval of the test
site or sites must be submitted to the address given in Sec. 53.4. The
request should include information identifying the type of candidate
method and one or more specific proposed test sites along with a
justification for each proposed specific site as described in paragraph
(b)(1) of this section. The EPA will evaluate each proposed site and
approve the site, disapprove the site, or request more information
about the site. Any such pre-test approval of a test site by the EPA
shall indicate only that the site meets the applicable test site
requirements for the candidate method type; it shall not indicate,
suggest, or imply that test data obtained at the site will necessarily
meet any of the applicable data acceptance requirements. The
Administrator may exercise discretion in selecting a different site (or
sites) for any additional tests the Administrator decides to conduct.
(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) Sampling or sample collection. All test concentration
measurements or samples shall be taken in such a way that both the
candidate method and the reference method obtain air samples that are
alike or as nearly identical as practical.
(e) Operation. Set-up and start-up of the test analyzer(s), test
sampler(s), and reference method analyzers or samplers shall be in
strict accordance with the applicable operation manual(s).
(f) 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 method (or portion thereof)
shall be calibrated according to the applicable operation
[[Page 61279]]
manual(s), if such calibration is a part of the method.
(g) 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 and PM10-2.5, all submitted information
must meet the requirements of the ANSI/ASQC E4 Standard, sections 6
(reference 1 of appendix A of this subpart).
Sec. 53.31 [Reserved]
Sec. 53.32 Test procedures for methods for SO2, CO,
O3, and NO2.
(a) Comparability. Comparability is shown for SO2, CO,
O3, and NO2 methods when the differences between:
(1) Measurements made by a candidate manual method or by a test
analyzer representative of a candidate automated method, and;
(2) Measurements made simultaneously by a reference method are less
than or equal to the values for maximum discrepancy specified in table
C-1 of this subpart.
(b) Test measurements. 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, as
described under paragraph (f)(4) of this section.
(c) Requirements for measurements or samples. All test measurements
made or test samples collected by means of a sample manifold as
specified in paragraph (f)(4) of this section shall be at a room
temperature between 20[deg] and 30[deg] C, and at a line voltage
between 105 and 125 volts. All methods shall be calibrated as specified
in Sec. 53.30(f) prior to initiation of the tests.
(d) Set-up and start-up. (1) Set-up and start-up of the test
analyzer, test sampler(s), and reference method 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.
(e) Range. (1) Except as provided in paragraph (e)(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.
(f) 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.
(4) 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 particulate matter and
trace gases, and to insure that identical samples reach the two
methods. If necessary, the concentration of pollutant in the sampled
ambient air may be augmented 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.
(g) Tests. (1) Conduct the first set of simultaneous measurements
with the candidate and reference methods:
(i) 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.
(ii) The pollutant concentration must fall within the specified
range as measured by the reference method.
(iii) 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.
(2) 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.
(3) The results of the first set of measurements shall be
interpreted as follows:
(i) Zero failures: The candidate method passes the test for
comparability.
[[Page 61280]]
(ii) Three or more failures: The candidate method fails the test
for comparability.
(iii) 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:
(A) One or two failures: The candidate method passes the test for
comparability.
(B) Three or more failures: The candidate method fails the test for
comparability.
(iv) 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.
(4) 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.
(5) 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 twenty-four (24) sequential 1-hour measurements.
(6) For O3 and CO, no more than six 1-hour measurements
shall be made per day. For SO2, 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.
(7) 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 Pb.
(a) Comparability. Comparability is shown for Pb methods when the
differences between:
(1) Measurements made by a candidate method, and
(2) Measurements made by the reference method on simultaneously
collected Pb samples (or the same sample, if applicable), are less than
or equal to the value specified in table C-3 of this subpart.
(b) Test measurements. 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 Pb concentrations in the specified range.
(c) Collocated samplers. The ambient air intake points of all the
candidate and reference method collocated samplers shall be positioned
at the same height above the ground level, and between 2 meters (1
meter for samplers with flow rates less than 200 liters per minute (L/
min)) and 4 meters apart. The samplers shall be oriented in a manner
that will minimize spatial and wind directional effects on sample
collection.
(d) Sample collection. Collect simultaneous 24-hour samples
(filters) of Pb at the test site or sites with both the reference and
candidate methods until at least 10 filter pairs have been obtained. A
candidate method which employs a sampler and sample collection
procedure that are identical to the sampler and sample collection
procedure specified in the reference method, but uses 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 each shall be divided
for respective analysis in accordance with the analytical procedures of
the candidate method and the reference method.
(e) 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 Pb at the following
nominal levels: 100 micrograms per strip ([mu]g/strip); 300 [mu]g/
strip; 750 [mu]g/strip. The true amount of Pb, in total [mu]g/strip,
will be provided with each audit sample.
(f) 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 Pb concentrations for the reference method samples in
micrograms per cubic meter ([mu]g/m3) for each analysis of
each filter. Calculate the indicated total Pb amount for the audit
samples in [mu]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 Pb concentration in [mu]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 Pb concentrations without a separable
procedure, C1A=C1B=C1C,
C2A=C2B=C2C, etc.
(g) Average Pb concentration. For the reference method, calculate
the average Pb concentration for each filter by averaging the
concentrations calculated from the three analyses using equation 1 of
this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.015
Where, i is the filter number.
(h) Accuracy. (1)(i) For the audit samples, calculate the average
Pb concentration for each strip by averaging the concentrations
calculated from the three analyses using equation 2 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.016
Where, i is audit sample number.
(ii) Calculate the percent difference (Dq) between the
indicated Pb concentration for each audit sample and the true Pb
concentration (Tq) using equation 3 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.017
(2) If any difference value (Dqi) exceeds 5
percent, the accuracy of the
[[Page 61281]]
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 (f) of this section, or the entire test
procedure (starting with paragraph (d) of this section) must be
repeated.
(i) Acceptable filter pairs. Disregard all filter pairs for which
the Pb concentration, as determined in paragraph (g) of this section by
the average of the three reference method determinations, falls outside
the range of 0.5 to 4.0 [mu]g/m3. All remaining filter pairs
must be subjected to the tests for precision and comparability in
paragraphs (j) and (k) of this section. At least five filter pairs must
be within the 0.5 to 4.0 [mu]g/m3 range for the tests to be
valid.
(j) 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, using equation 4 or equation 5 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.018
or
[GRAPHIC] [TIFF OMITTED] TR17OC06.019
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 (f) of this
section, or the entire test procedure (starting with paragraph (d) 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.
(k) Test for comparability. (1) For each filter or analytical
sample 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
using equation 6 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.020
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) exceed 20 percent, the candidate method fails the test for
comparability.
(4) The candidate method must pass both the precision test
(paragraph (j) of this section) and the comparability test (paragraph
(k) of this section) to qualify for designation as an equivalent
method.
Sec. 53.34 Test procedure for methods for PM10 and Class I methods
for PM2.5.
(a) Comparability. Comparability is shown for PM10
methods and for Class I methods for PM2.5 when the
relationship between:
(1) Measurements made by a candidate method, and
(2) Measurements made by a corresponding reference method on
simultaneously collected samples (or the same sample, if applicable) at
each of one or more test sites (as required) is such that the linear
regression parameters (slope, intercept, and correlation coefficient)
describing the relationship meet the requirements specified in table C-
4 of this subpart.
(b) 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 the minimum number of test PM10
concentrations in the ranges specified in table C-4 of this subpart.
The tests at the two sites may be conducted in different calendar
seasons, if appropriate, to provide PM10 concentrations in
the specified ranges.
(c) 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.
(d) Methods for PM2.5. Augmentation of pollutant concentrations is
not permitted, hence appropriate test sites must be selected to provide
the minimum number of test measurement sets to meet the requirements
for PM2.5 concentrations in the ranges specified in table C-
4 of this subpart. Only one test site is required, and the site need
only meet the PM2.5 ambient concentration levels required by
table C-4 of this subpart and the requirements of Sec. 53.30(b) of
this subpart. A total of 10 valid measurement sets is required.
(e) Collocated measurements. (1) 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.
(2) The ambient air intake points of all the candidate and
reference method collocated samplers or analyzers shall be positioned
at the same height above the ground level, and between 2 meters (1
meter for samplers or analyzers with flow rates less than 200 L/min)
and 4 meters apart. The samplers shall be oriented in a manner that
will minimize spatial and wind directional effects on sample
collection.
(3) At each site, obtain as many sets of simultaneous
PM10 or PM2.5 measurements as necessary (see
table C-4 of this subpart), each set consisting of three reference
method and three candidate method measurements, all obtained
simultaneously.
(4) Candidate PM10 method measurements shall be nominal
24-hour (1 hour) integrated measurements or shall be
averaged to obtain the mean concentration for a nominal 24-hour period.
PM2.5 measurements may be either nominal 24-or 48-hour
integrated measurements. All collocated measurements in a measurement
set must cover the same nominal 24-or 48-hour time period.
(5) 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 [mu]g/m3. If the
conditions of paragraph (c) of this section apply, collect sample sets
only
[[Page 61282]]
with the three reference method samplers. Guidance for quality
assurance procedures for PM2.5 methods is found in ``Quality
Assurance Document 2.12'' (reference (2) in appendix A to this
subpart).
(f) 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.
(g) Calculation of reference method averages and precisions. (1)
For each of the measurement sets, calculate the average PM10
or PM2.5 concentration obtained with the reference method
samplers, using equation 7 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.021
Where:
R = The concentration measurements from the reference methods;
i = The sampler number; and
j = The measurement set number.
(2) For each of the measurement sets, calculate the precision of
the reference method PM10 or PM2.5 measurements
as the standard deviation, PRj, using equation 8 of this
section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.022
(3) For each measurement set, also calculate the precision of the
reference method PM10 or PM2.5 measurements as
the relative standard deviation, RPRj, in percent, using
equation 9 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.023
(h) Acceptability of measurement sets. Each measurement set is
acceptable and valid only if the three reference method measurements
and the three candidate method measurements are obtained and are valid,
Rj falls within the acceptable concentration range specified
in table C-4 of this subpart, and either PRj or
RPRj is within the corresponding limit for reference method
precision specified in table C-4 of this subpart. For each site, table
C-4 of this subpart specifies the minimum number of measurement sets
required having Rj above and below specified concentrations
for 24- or 48-hour samples. Additional measurement sets shall be
obtained, as necessary, to provide the minimum number of acceptable
measurement sets for each category and the minimum total number of
acceptable measurement sets for each test site. If more than the
minimum number of measurement sets are collected that meet the
acceptability criteria, all such measurement sets shall be used to
demonstrate comparability.
(i) Candidate method average concentration measurement. For each of
the acceptable measurement sets, calculate the average PM10
or PM2.5 concentration measurements obtained with the
candidate method samplers, using equation 10 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.024
Where:
C = The concentration measurements from the candidate methods;
i = The measurement number in the set; and
j = The measurement set number.
(j) Test for comparability. (1) For each site, plot all of 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.
(2) To pass the test for comparability, the slope, intercept, and
correlation coefficient calculated under paragraph (j)(1) of this
section must be within the limits specified in table C-4 of this
subpart for all test sites.
Sec. 53.35 Test procedure for Class II and Class III methods for
PM2.5 and PM10-2.5.
(a) Overview. Class II and Class III candidate equivalent methods
shall be tested for comparability of PM2.5 or
PM10-2.5 measurements to corresponding collocated
PM2.5 or PM10-2.5 reference method measurements
at each of multiple field sites, as required. Comparability is shown
for the candidate method when simultaneous collocated measurements made
by candidate and reference methods meet the comparability requirements
specified in this section Sec. 53.35 and in table C-4 of this subpart
at each of the required test sites.
(b) Test sites and seasons. A summary of the test site and seasonal
testing requirements is presented in table C-5 of this subpart.
(1) Test sites. Comparability testing is required at each of the
applicable U.S. test sites required by this paragraph (b). Each test
site must also meet the general test site requirements specified in
Sec. 53.30(b).
(i) PM2.5 Class II and Class III candidate methods. Test sites
should be chosen to provide representative chemical and meteorological
characteristics with respect to nitrates, sulfates, organic compounds,
and various levels of temperature, humidity, wind, and elevation. For
Class III methods, one test site shall be selected in each of the
following four general locations (A, B, C, and D). For Class II
methods, two test sites, one western site (A or B) and one midwestern
or eastern site (C or D), shall be selected from these locations.
(A) Test site A shall be in the Los Angeles basin or California
Central Valley area in a location that is characterized by relatively
high PM2.5, nitrates, and semi-volatile organic pollutants.
(B) Test site B shall be in a western city such as Denver, Salt
Lake City, or Albuquerque in an area characterized by cold weather,
higher elevation, winds, and dust.
(C) Test site C shall be in a midwestern city characterized by
substantial temperature variation, high nitrates, and wintertime
conditions.
(D) Test site D shall be in a northeastern or mid-Atlantic city
that is seasonally characterized by high sulfate concentrations and
high relative humidity.
(ii) PM10-2.5 Class II and Class III candidate methods. Test sites
shall be chosen to provide modest to high levels of PM10-2.5
representative of locations in proximity to urban sources of
PM10-2.5 such as high-density traffic on paved roads,
industrial sources, and construction activities. For Class III methods,
one test site shall be selected in each of the four following general
locations (A, B, C, and D), and at least one of the test sites shall
have characteristic wintertime temperatures of 0[deg] C or lower. For
Class II methods, two test sites, one western site (A or B) and one
midwestern or eastern site (C or D), shall be selected from these
locations.
(A) Test site A shall be in the Los Angeles basin or the California
Central Valley area in a location that is characterized by relatively
high PM2.5, nitrates, and semi-volatile organic pollutants.
[[Page 61283]]
(B) Test site B shall be in a western city characterized by a high
ratio of PM10-2.5 to PM2.5, with exposure to
windblown dust, such as Las Vegas or Phoenix.
(C) Test site C shall be in a midwestern city characterized by
substantial temperature variation, high nitrates, and wintertime
conditions.
(D) Test site D shall be in a large city east of the Mississippi
River, having characteristically high sulfate concentrations and high
humidity levels.
(2) Test seasons. (i) For PM2.5 and PM10-2.5
Class III candidate methods, test campaigns are required in both summer
and winter seasons at test site A, in the winter season only at test
sites B and C, and in the summer season only at test site D. (A total
of five test campaigns is required.) The summer season shall be defined
as the typically warmest three or four months of the year at the site;
the winter season shall be defined as the typically coolest three or
four months of the year at the site.
(ii) For Class II PM2.5 and PM10-2.5
candidate methods, one test campaign is required at test site A or B
and a second test campaign at test site C or D (total of two test
campaigns).
(3) Test concentrations. The test sites should be selected to
provide ambient concentrations within the concentration limits
specified in table C-4 of this subpart, and also to provide a wide
range of test concentrations. A narrow range of test concentrations may
result in a low concentration coefficient of variation statistic for
the test measurements, making the test for correlation coefficient more
difficult to pass (see paragraph (h) of this section, test for
comparison correlation).
(4) Pre-approval of test sites. The EPA recommends that the
applicant seek EPA approval of each proposed test site prior to
conducting test measurements at the site. To do so, the applicant
should submit a request for approval as described in Sec. 53.30(b)(2).
(c) Collocated measurements. (1) For each test campaign, three
reference method samplers and three candidate method samplers or
analyzers shall be installed and operated concurrently at each test
site within each required season (if applicable), as specified in
paragraph (b) of this section. All reference method samplers shall be
of single-filter design (not multi-filter, sequential sample design).
Each candidate method shall be setup and operated in accordance with
its associated manual referred to in Sec. 53.4(b)(3) and in accordance
with applicable guidance in ``Quality Assurance Document 2.12''
(reference (2) in appendix A to this subpart). All samplers or
analyzers shall be placed so that they sample or measure air
representative of the surrounding area (within one kilometer) and are
not unduly affected by adjacent buildings, air handling equipment,
industrial operations, traffic, or other local influences. The ambient
air inlet points of all samplers and analyzers shall be positioned at
the same height above the ground level and between 2 meters (1 meter
for instruments having sample inlet flow rates less than 200 L/min) and
4 meters apart.
(2) A minimum of 23 valid and acceptable measurement sets of
PM2.5 or PM10-2.5 24-hour (nominal) concurrent
concentration measurements shall be obtained during each test campaign
at each test site. To be considered acceptable for the test, each
measurement set shall consist of at least two valid reference method
measurements and at least two valid candidate method measurements, and
the PM2.5 or PM10-2.5 measured concentration, as
determined by the average of the reference method measurements, must
fall within the acceptable concentration range specified in table C-4
of this subpart. Each measurement set shall include all valid
measurements obtained. For each measurement set containing fewer than
three reference method measurements or fewer than three candidate
method measurements, an explanation and appropriate justification shall
be provided to account for the missing measurement or measurements.
(3) More than 23 valid measurement sets may be obtained during a
particular test campaign to provide a more advantageous range of
concentrations, more representative conditions, additional higher or
lower measurements, or to otherwise improve the comparison of the
methods. All valid data sets obtained during each test campaign shall
be submitted and shall be included in the analysis of the data.
(4) The integrated-sample reference method measurements shall be of
at least 22 hours and not more than 25 hours duration. Each reference
method sample shall be retrieved promptly after sample collection and
analyzed according to the reference method to determine the
PM2.5 or PM10-2.5 measured concentration in
[mu]g/m\3\. Guidance and quality assurance procedures applicable to
PM2.5 or PM10-2.5 reference methods are found in
``Quality Assurance Document 2.12'' (reference (2) in appendix A to
this subpart).
(5) Candidate method measurements shall be timed or processed and
averaged as appropriate to determine an equivalent mean concentration
representative of the same time period as that of the concurrent
integrated-sample reference method measurements, such that all
measurements in a measurement set shall be representative of the same
time period. In addition, hourly average concentration measurements
shall be obtained from each of the Class III candidate method analyzers
for each valid measurement set and submitted as part of the application
records.
(6) In the following tests, all measurement sets obtained at a
particular test site, from both seasonal campaigns if applicable, shall
be combined and included in the test data analysis for the site. Data
obtained at different test sites shall be analyzed separately. All
measurements should be reported as normally obtained, and no
measurement values should be rounded or truncated prior to data
analysis. In particular, no negative measurement value, if otherwise
apparently valid, should be modified, adjusted, replaced, or eliminated
merely because its value is negative. Calculated mean concentrations or
calculated intermediate quantities should retain at least one order-of-
magnitude greater resolution than the input values. All measurement
data and calculations shall be recorded and submitted in accordance
with Sec. 53.30(g), including hourly test measurements obtained from
Class III candidate methods.
(d) Calculation of mean concentrations--(1) Reference method
outlier test. For each of the measurement sets for each test site,
check each reference method measurement to see if it might be an
anomalous value (outlier) as follows, where Ri,j is the
measurement of reference method sampler i on test day j. In the event
that one of the reference method measurements is missing or invalid due
to a specific, positively-identified physical cause (e.g., sampler
malfunction, operator error, accidental damage to the filter, etc.; see
paragraph (c)(2) of this section), then substitute zero for the missing
measurement, for the purposes of this outlier test only.
(i) Calculate the quantities 2 x R1,j/(R1,j +
R2,j) and 2 x R1,j/(R1,j +
R3,j). If both quantities fall outside of the interval,
(0.93, 1.07), then R1,j is an outlier.
(ii) Calculate the quantities 2 x R2,j/(R2,j
+ R1,j) and 2 x R2,j/(R2,j +
R3,j). If both quantities fall outside of the interval,
(0.93, 1.07), then R2,j is an outlier.
(iii) Calculate the quantities 2 x R3,j/(R3,j
+ R1,j) and 2 x R3,j/(R3,j +
R2,j). If both quantities fall outside of the
[[Page 61284]]
interval, (0.93, 1.07), then R3,j is an outlier.
(iv) If this test indicates that one of the reference method
measurements in the measurement set is an outlier, the outlier
measurement shall be eliminated from the measurement set, and the other
two measurements considered valid. If the test indicates that more than
one reference method measurement in the measurement set is an outlier,
the entire measurement set (both reference and candidate method
measurements) shall be excluded from further data analysis for the
tests of this section.
(2) For each of the measurement sets for each test site, calculate
the mean concentration for the reference method measurements, using
equation 11 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.025
Where:
Rj = The mean concentration measured by the reference
method for the measurement set;
Ri,j = The measurement of reference method sampler i on
test day j; and
n = The number of valid reference method measurements in the
measurement set (normally 3).
(3) Any measurement set for which Rj does not fall in
the acceptable concentration range specified in table C-4 of this
subpart is not valid, and the entire measurement set (both reference
and candidate method measurements) must be eliminated from further data
analysis.
(4) For each of the valid measurement sets at each test site,
calculate the mean concentration for the candidate method measurements,
using equation 12 of this section. (The outlier test in paragraph
(d)(1) of this section shall not be applied to the candidate method
measurements.)
[GRAPHIC] [TIFF OMITTED] TR17OC06.026
Where:
Cj = The mean concentration measured by the candidate
method for the measurement set;
Ci,j = The measurement of the candidate method sampler or
analyzer i on test day j; and
m = The number of valid candidate method measurements in the
measurement set (normally 3).
(e) Test for reference method precision. (1) For each of the
measurement sets for each site, calculate an estimate for the relative
precision of the reference method measurements, RPj, using
equation 13 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.027
(2) For each site, calculate an estimate of reference method
relative precision for the site, RP, using the root mean square
calculation of equation 14 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.028
Where, J is the total number of valid measurement sets for the site.
(3) Verify that the estimate for reference method relative
precision for the site, RP, is not greater than the value specified for
reference method precision in table C-4 of this subpart. A reference
method relative precision greater than the value specified in table C-4
of this subpart indicates that quality control for the reference method
is inadequate, and corrective measures must be implemented before
proceeding with the test.
(f) Test for candidate method precision. (1) For each of the
measurement sets, for each site, calculate an estimate for the relative
precision of the candidate method measurements, CPj, using
equation 15 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.029
(2) For each site, calculate an estimate of candidate method
relative precision for the site, CP, using the root mean square
calculation of equation 16 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.030
Where, J is the total number of valid measurement sets for the site.
(3) To pass the test for precision, the mean candidate method
relative precision at each site must not be greater than the value for
candidate method precision specified in table C-4 of this subpart.
(g) Test for additive and multiplicative bias (comparative slope
and intercept). (1) For each test site, calculate the mean
concentration measured by the reference method, R, using equation 17 of
this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.031
(2) For each test site, calculate the mean concentration measured
by the candidate method, C, using equation 18 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.032
(3) For each test site, calculate the linear regression slope and
intercept of the mean candidate method measurements (Cj)
against the mean reference method measurements (Rj), using
equations 19 and 20 of this section, respectively:
[GRAPHIC] [TIFF OMITTED] TR17OC06.033
[GRAPHIC] [TIFF OMITTED] TR17OC06.034
(4) To pass this test, at each test site:
(i) The slope (calculated to at least 2 decimal places) must be in
the interval specified for regression slope in table C-4 of this
subpart; and
(ii) The intercept (calculated to at least 2 decimal places) must
be in the interval specified for regression intercept in table C-4 of
this subpart.
(iii) The slope and intercept limits are illustrated in figures C-2
and C-3 of this subpart.
(h) Tests for comparison correlation. (1) For each test site,
calculate the (Pearson) correlation coefficient, r (not the coefficient
of determination, r\2\), using equation 21 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.035
[[Page 61285]]
(2) For each test site, calculate the concentration coefficient of
variation, CCV, using equation 22 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.036
(3) To pass the test, the correlation coefficient, r, for each test
site must not be less than the values, for various values of CCV,
specified for correlation in table C-4 of this subpart. These limits
are illustrated in figure C-4 of this subpart.
Tables to Subpart C of Part 53
Table C-1 to Subpart C of Part 53.--Test Concentration Ranges, Number of Measurements Required, and Maximum
Discrepancy Specification
----------------------------------------------------------------------------------------------------------------
Simultaneous measurements required
-------------------------------------------- Maximum
Concentration 1-hr 24-hr discrepancy
Pollutant range, parts per -------------------------------------------- specification,
million First Second First Second parts per
set set set 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 to Subpart C of Part 53.--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 to Subpart C of Part 53.--Test Specifications for Pb Methods
------------------------------------------------------------------------
------------------------------------------------------------------------
Concentration range, [mu]g/m3.............................. 0.5-4.0
Minimum number of 24-hr measurements....................... 5
Maximum analytical precision, percent...................... 15
Maximum analytical accuracy, percent....................... 5
Maximum difference, percent of reference method............ 20
------------------------------------------------------------------------
Table C-4 to Subpart C of Part 53.--Test Specifications for PM10, PM2.5 and PMR10-2.5 Candidate Equivalent Methods
--------------------------------------------------------------------------------------------------------------------------------------------------------
PM2.5 PM10-2.5
Specification PM10 -----------------------------------------------------------------------------------------------
Class I Class II Class III Class II Class III
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acceptable concentration range 15-300................. 3-200............. 3-200............ 3-200............ 3-200............ 3-200
(Rj), [mu]g/m\3\.
Minimum number of test sites... 2...................... 1................. 2................ 4................ 2................ 4
Minimum number of candidate 3...................... 3................. 3\1\............. 3\1\............. 3\1\............. 3\1\
method samplers or analyzers
per site.
[[Page 61286]]
Number of reference method 3...................... 3................. 3\1\............. 3\1\............. 3\1\............. 3\1\
samplers per site.
Minimum number of acceptable
sample sets per site for PM10
methods:
Rj < 60 [mu]g/m\3\......... 3
Rj > 60 [mu]g/m\3\......... 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total.................. 10
Minimum number of acceptable
sample sets per site for PM2.5
and PM10 2.5 candidate
equivalent methods:
Rj < 30 [mu]g/m\3\ for 24- ....................... 3
hr or Rj < 20 [mu]g/m\3\
for 48-hr samples.
Rj > 30 [mu]g/m\3\ for 24- ....................... 3
hr or Rj > 20 [mu]g/m\3\
for 48-hr samples.
Each season................ ....................... 10................ 23............... 23............... 23............... 23
Total, each site........... ....................... 10................ 23............... 23 (46 for two- 23............... 23 (46 for two-
season sites). season sites)
Precision of replicate 5 [mu]g/m\3\ or 7%..... 2 [mu]g/m\3\ or 5% 10%\2\........... 10%\2\........... 10%\2\........... 10%\2\
reference method measurements,
PRj or RPRj', respectively; RP
for Class II or III PM2.5 or
PM10 2.5', maximum.
Precision of PM2.5 or PM10 2.5 ....................... .................. 10%\2\........... 15%\2\........... 15%\2\........... 15%\2\
candidate method, CP, each
site.
Slope of regression 10.10...... 10.05. 10.10 10.10 10.10 10.12
relationship.
Intercept of regression 05......... 01.... Between: 13.55- Between: 15.05- Between: 62.05- Between: 70.50-
relationship, [mu]g/m\3\. (15.05 x slope), (17.32 x slope), (70.5 x slope), (82.93 x slope),
but not less but not less but not less but not less
than -1.5; and than -2.0; and than -3.5; and than -7.0; and
16.56-(15.05 x 15.05-(13.20 x 78.95-(70.5 x 70.50-(61.16 x
slope), but not slope), but not slope), but not slope), but not
more than + 1.5. more than + 2.0. more than + 3.5. more than + 7.0
Correlation of reference method [gteqt]0.97............ [gteqt]0.97....... [gteqt]0.93 . . . . . . . CCV[lteqt]0.4; [gteqt]0.85 + 0.2 x CCV . . for
and candidate method 0.4[lteqt]CCV[lteqt]0.5; [gteqt]0.95 . . . . . . . for CCV[gteqt]0.5
measurements.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Some missing daily measurement values may be permitted; see test procedure.
\2\ Calculated as the root mean square over all measurement sets
Table C-5 to Subpart C of Part 53--Summary of Comparability Field Testing Campaign Site and Seasonal Requirements for Class II and III FEMs for PM10-2.5
and PM2.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Candidate method Test site A B C D
--------------------------------------------------------------------------------------------------------------------------------------------------------
PM2.5.............................. Test site location Los Angeles basin or Western city such as Midwestern city...... Northeastern or mid-
area. California Central Denver, Salt Lake Atlantic city.
Valley. City, or Albuquerque.
Test site Relatively high PM2.5, Cold weather, higher Substantial High sulfate and high
characteristics. nitrates, and semi- elevation, winds, temperature relative humidity.
volatile organic and dust. variation, high
pollutants. nitrates, wintertime
conditions.
Class III Field test Winter and summer..... Winter only.......... Winter only.......... Summer only.
campaigns (Total: 5).
--------------------------------------------------------------------------------------------
Class II Field test Site A or B, any season
campaigns (Total: 2).
Site C or D, any season.
--------------------------------------------------------------------------------------------
[[Page 61287]]
PM10-2.5........................... Test site location Los Angeles basin or Western city such as Midwestern city...... Large city east of
area. California Central Las Vegas or Phoenix. the Mississippi
Valley. River.
--------------------------------------------------------------------------------------------
Test site Relatively high PM2.5, High PM10-2.5 to Substantial High sulfate and high
characteristics. nitrates, and semi- PM2.5 ratio, temperature relative humidity.
volatile organic windblown dust. variation, high
pollutants. nitrates, wintertime
conditions.
Class III Field test Winter and summer..... Winter only.......... Winter only.......... Summer only.
campaigns (Total: 5).
--------------------------------------------------------------------------------------------
Class II Field test Site A or B, any season
campaigns (Total: 2).
Site C or D, any season.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Figures to Subpart C of Part 53
Figure C-1 to Subpart C of Part 53--Suggested Format for Reporting Test
Results for Methods for SO2, CO, O3,
NO2
Candidate Method-------------------------------------------------------
Reference Method-------------------------------------------------------
Applicant--------------------------------------------------------------
[ballot] First Set [ballot] Second Set [ballot] Type
[ballot] 1 Hour [ballot] 24 Hour
--------------------------------------------------------------------------------------------------------------------------------------------------------
Concentration, ppm
Concentration range Date Time -------------------------------- Difference Table C-1 Pass or fail
Candidate Reference spec.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low 1
------------------------------------------------------------------------------------------------------------------------
-------- ppm 2
------------------------------------------------------------------------------------------------------------------------
to -------- ppm 3
------------------------------------------------------------------------------------------------------------------------
4
------------------------------------------------------------------------------------------------------------------------
5
------------------------------------------------------------------------------------------------------------------------
6
--------------------------------------------------------------------------------------------------------------------------------------------------------
Medium 1
------------------------------------------------------------------------------------------------------------------------
-------- ppm 2
------------------------------------------------------------------------------------------------------------------------
to -------- ppm 3
------------------------------------------------------------------------------------------------------------------------
4
------------------------------------------------------------------------------------------------------------------------
5
------------------------------------------------------------------------------------------------------------------------
6
--------------------------------------------------------------------------------------------------------------------------------------------------------
High 1
------------------------------------------------------------------------------------------------------------------------
-------- ppm 2
------------------------------------------------------------------------------------------------------------------------
to -------- ppm 3
------------------------------------------------------------------------------------------------------------------------
4
------------------------------------------------------------------------------------------------------------------------
5
------------------------------------------------------------------------------------------------------------------------
6
------------------------------------------------------------------------------------------------------------------------
7
------------------------------------------------------------------------------------------------------------------------
8
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total
Failures:
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 61288]]
[GRAPHIC] [TIFF OMITTED] TR17OC06.057
[GRAPHIC] [TIFF OMITTED] TR17OC06.058
[[Page 61289]]
[GRAPHIC] [TIFF OMITTED] TR17OC06.059
Appendix to Subpart C of Part 53
Appendix A to Subpart C of Part 53--References
(1) American National Standard Quality Systems for Environmental
Data and Technology Programs--Requirements with guidance for use,
ANSI/ASQC E4-2004. Available from American Society for Quality, P.O.
Box 3005, Milwaukee, WI 53202 (http://qualitypress.asq.org).
(2) Quality Assurance Guidance Document 2.12. Monitoring
PM2.5 in Ambient Air Using Designated Reference or Class
I Equivalent Methods. U.S. EPA, National Exposure Research
Laboratory, Research Triangle Park, NC, November 1998 or later
edition. Currently available at http://www.epa.gov/ttn/amtic/pmqainf.html.
Subpart E--Procedures for Testing Physical (Design) and Performance
Characteristics of Reference Methods and Class I and Class II
Equivalent Methods for PM2.5 or PM10-2.5
0
7. The heading for subpart E is revised as set out above.
0
8. Section 53.50 is revised to read as follows:
Sec. 53.50 General provisions.
(a) A candidate method for PM2.5 or PM10-2.5
described in an application for a FRM or FEM determination submitted
under Sec. 53.4 shall be determined by the EPA to be a FRM or a Class
I, II, or III FEM on the basis of the definitions for such methods
given in Sec. 53.1. 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 or PM10-2.5 sampler associated with a
candidate reference method or Class I or Class II equivalent method
meets all design and performance specifications set forth in appendix L
or O, respectively, of part 50 of this chapter as well as additional
requirements specified in this subpart E. Some or all of these tests
may also be applicable to a candidate Class III equivalent method or
analyzer, as may be determined under Sec. 53.3(b)(3).
(b) PM2.5 methods--(1) Reference method. A sampler associated with
a candidate reference method for PM2.5 shall be subject to
the provisions, specifications, and test procedures prescribed in
Sec. Sec. 53.51 through 53.58.
(2) Class I method. A sampler associated with a candidate Class I
equivalent method for PM2.5 shall be subject to the
provisions, specifications, and test procedures prescribed in all
sections of this subpart.
(3) Class II method. A sampler associated with a candidate Class II
equivalent method 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 or as specified in Sec. 53.3(a)(3).
(c) PM10-2.5 methods--(1) Reference method. A sampler
associated with a reference method for PM10-2.5, as
specified in appendix O to part 50 of this chapter, shall be subject to
the requirements in this paragraph (c)(1).
(i) The PM2.5 sampler of the PM10-2.5 sampler
pair shall be verified to be either currently designated under this
part 53 as a FRM for PM2.5, or shown to meet all
requirements for designation as a FRM for PM2.5, in
accordance with this part 53.
(ii) The PM10C sampler of the PM10-2.5
sampler pair shall be verified to be of like manufacturer, design,
configuration, and fabrication to the PM2.5 sampler of the
PM10-2.5 sampler pair, except for replacement of the
particle size separator specified in section 7.3.4 of appendix L to
part 50 of this chapter with the downtube extension as specified in
Figure O-1 of appendix O to part 50 of this chapter.
(iii) For samplers that meet the provisions of paragraphs (c)(1)(i)
and (ii) of this section, the candidate PM10-2.5 reference
method may be determined to be a FRM without further testing.
(2) Class I method. A sampler associated with a Class I candidate
equivalent method for PM10-2.5 shall meet the requirements
in this paragraph (c)(2).
(i) The PM2.5 sampler of the PM10-2.5 sampler
pair shall be verified to be either currently designated under this
part 53 as a FRM or Class I FEM for PM2.5, or shown to meet
all requirements for designation as a FRM or Class I FEM for
PM2.5, in accordance with this part 53.
(ii) The PM10c sampler of the PM10-2.5
sampler pair shall be verified to be of similar design to the
PM10-2.5 sampler and to meet all requirements for
designation as a FRM or Class I FRM for PM2.5, in accordance
with this part 53, except for replacement of the particle size
separator specified in section 7.3.4
[[Page 61290]]
of appendix L to part 50 of this chapter with the downtube extension as
specified in Figure O-1 of appendix O to part 50 of this chapter.
(iii) For samplers that meet the provisions of paragraphs (c)(2)(i)
and (ii) of this section, the candidate PM10-2.5 method may
be determined to be a Class I FEM without further testing.
(3) Class II method. A sampler associated with a Class II candidate
equivalent method for PM10-2.5 shall be subject to the
applicable requirements of this subpart E, as described in Sec.
53.3(a)(5).
(d) 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 or O, as applicable. The test procedures prescribed in
Sec. Sec. 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 or
O, as applicable, 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.
(e) Test procedures prescribed in Sec. 53.59 do not apply to
candidate reference method samplers. These procedures apply primarily
to candidate Class I or Class II equivalent method samplers for
PM2.5 or PM10-2.5 that have a sample air flow
path configuration upstream of the sample filter that is modified from
that specified for the FRM sampler, as set forth in 40 CFR part 50,
appendix L, Figures L-1 to L-29 or 40 CFR part 50 appendix O, Figure O-
1, if applicable, 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 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.
(f) A 10-day operational field test of measurement precision is
required under Sec. 53.58 for both FRM and Class I FEM samplers for
PM2.5. This test requires collocated operation of three
candidate method samplers at a field test site. For candidate FEM
samplers, this test may be combined and carried out concurrently with
the test for comparability to the FRM specified under Sec. 53.34,
which requires collocated operation of three FRM samplers and three
candidate FEM samplers.
(g) 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 6) and Part C, (section 7) 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.
0
9. Section 53.51 is revised to read as follows:
Sec. 53.51 Demonstration of compliance with design specifications and
manufacturing and test requirements.
(a) Overview. (1) Paragraphs (a) through (f) of this section
specify certain documentation that must be submitted and tests that are
required to demonstrate that samplers associated with a designated FRM
or FEM for PM2.5 or PM10-2.5 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
or PM10-2.5 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 by paragraph (d) of
this section to verify that critical features of FRM samplers--the
particle size separator and the surface finish of surfaces specified to
be anodized--meet the specifications of 40 CFR part 50, appendix L or
appendix O, as applicable. 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 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-certified auditors 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). The EPA has determined
that acceptable technical judgment for review of this manual may not be
assured by ISO-certified auditors, and approval of this manual will
therefore be performed by EPA.
(b) ISO registration of manufacturing facility. The applicant must
submit documentation verifying that the samplers identified and sold as
part of a designated PM2.5 or PM10-2.5 FRM or FEM
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.
(c) Sampler manufacturing quality control. The manufacturer must
ensure that all components used in the manufacture of PM2.5
or PM10-2.5 samplers to be sold as part of a FRM or FEM and
that are specified by design in 40 CFR part 50, appendix L or O (as
applicable), 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
[[Page 61291]]
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 (WINS) impactor jet diameter. For samplers utilizing
the WINS impactor particle size separator specified in paragraphs
7.3.4.1, 7.3.4.2, and 7.3.4.3 of appendix L to part 50 of this chapter,
the diameter of the jet of each impactor manufactured for a
PM2.5 or PM10-2.5 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) VSCC separator. For samplers utilizing the BGI
VSCCTM Very Sharp Cut Cyclone particle size separator
specified in paragraph 7.3.4.4 of appendix L to part 50 of this
chapter, the VSCC manufacturer shall identify the critical dimensions
and manufacturing tolerances for the device, develop appropriate test
procedures to verify that the critical dimensions and tolerances are
maintained during the manufacturing process, and carry out those
procedures on each VSCC manufactured to verify conformance of the
manufactured products. The manufacturer shall also maintain records of
these tests and their results and 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.
(3) 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 or O (as applicable), 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 FRM or FEM 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 FRM or FEM devices. The completed
checklist shall be submitted with the application for FRM or FEM
determination.
0
10. Section 53.52 is amended by revising paragraph (e)(1) to read as
follows:
Sec. 53.52 Leak check 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 PM samples, except that the
sample air inlet shall be removed and the flow rate measurement adaptor
shall be installed on the sampler's downtube.
* * * * *
0
11. Section 53.53 is amended by revising paragraph (e)(1) to read as
follows:
Sec. 53.53 Test for flow rate accuracy, regulation, measurement
accuracy, and cut-off.
* * * * *
(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 PM 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.
* * * * *
0
12. Section 53.54 is amended by revising paragraph (d)(1) to read as
follows:
Sec. 53.54 Test for proper sampler operation following power
interruptions.
* * * * *
(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 PM 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.
* * * * *
0
13. Section 53.33 is amended by:
0
a. Revising paragraphs (a)(1) introductory text and (a)(2).
0
b. Revising paragraph (e)(1).
0
c. Revising paragraph (g)(5)(i) to read as follows.
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
[[Page 61292]]
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:
* * * * *
(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 or PM10-2.5 method (as
applicable) to pass this test procedure.
* * * * *
(e) * * * (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 PM
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.
* * * * *
(g) * * *
(5) * * * (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:
[GRAPHIC] [TIFF OMITTED] TR17OC06.037
Where:
Tind,ave = The mean ambient air temperature indicated by
the test sampler, [deg]C; and
Tref,ave = The mean ambient air temperature measured by
the reference temperature instrument, [deg]C.
* * * * *
0
14. Section 53.56 is amended by revising paragraphs (a)(2) and (e)(1)
to read as follows:
Sec. 53.56 Test for effect of variations in ambient pressure.
(a) * * *
(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 or PM10-2.5 method (as
applicable) to pass this test procedure.
* * * * *
(e) * * * (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 PM
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.
* * * * *
0
15. Section 53.57 is amended by revising paragraphs (a), (b), and
(e)(1) to read as follows:
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 PM 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 by the sampler until the filter is
retrieved from the sampler for laboratory analysis.
* * * * *
(e) * * * (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 PM
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 five additional filters for magazine-type
sequential samplers) as directed by the sampler's operation or
instruction manual.
* * * * *
0
16. Section 53.58 is revised to read as follows:
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 PM 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
[[Page 61293]]
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 PM
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 (or
PM10-2.5, as applicable) 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 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
PM samples in accordance with the instructions in the associated manual
referred to in Sec. 53.4(b)(3) and also 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 (1 for samplers with flow rates less
than 200 L/min.) 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
five 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 PM test
samples.
(2) Collect either a nominal 24-hour or 48-hour atmospheric PM
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 PM mass concentration for each sample in
accordance with the applicable procedures prescribed for the candidate
method in appendix L or appendix O, as applicable, of part 50 of this
chapter, and in accordance with the associated manual referred to in
Sec. 53.4(b)(3) and 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 (nominal) 24-hour or 48-hour PM 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 PM 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 PM concentrations as Cave,j where j is
the test period using equation 26 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.038
(ii) If Cave,j < 3 [mu]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
periods, as the standard deviation, using equation 27 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.039
(ii) For each of the 10 test periods, also calculate and record the
precision as the relative standard deviation, in percent, using
equation 28 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.040
(h) Test results. (1) The candidate method passes the precision
test if either Pj or RPj is less than or equal to
the corresponding specification in table E-1 of this subpart for all 10
test periods.
(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 [mu]g.
0
17. Section 53.59 is amended by revising paragraphs (a) and (b)(5) to
read as follows:
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 significantly from that specified for
reference method samplers as specified in 40 CFR part 50, appendix L or
appendix O, as applicable. The test requirements and performance
specifications for this test are summarized in table E-1 of this
subpart.
(b) * * *
(5) An added component is any physical part of the sampler which is
different in some way from that specified for a reference method
[[Page 61294]]
sampler in 40 CFR part 50, appendix L or appendix O, as applicable,
such as a device or means to allow or cause the aerosol to be routed to
one of several channels.
* * * * *
0
18. Table E-1 to subpart E is revised to read as follows:
Table E-1 to Subpart E of Part 53.--Summary of Test Requirements for Reference and Class I Equivalent Methods
for PM2.5 and PM10 2.5
----------------------------------------------------------------------------------------------------------------
Performance Part 50, appendix
Subpart E procedure Performance test specification Test conditions L reference
----------------------------------------------------------------------------------------------------------------
Sec. 53.52 Sample 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 ? 5% L/ (a) 6-hour normal Sec. 7.4.1,
1. Mean........... 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) Normal 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 ?30 restriction used
seconds. for cut-off test.
Sec. 53.54 Power interruption Sample flow rate:. 1. 16.67 ? 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. ? mm Hg pressure Sec. 7.4.13
of power 2 min if >60 drop to simulate Sec. 7.4.15.4
interruptions. seconds. loaded filter. Sec. 7.4.15.5.
6. Elapsed sample 6. ? (d) 6 power
time. 20 seconds. interruptions of
7. Sample volume.. 7. various durations.
?2%, max.
Sec. 53.55 Temperature and Sample flow rate.. 1. 16.6 ? 5% L/min. operational test. Sec. 7.4.2
2. Regulation..... 2. 2%, max........ (b) Normal 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 ? ? 5% L/min. operational test. Sec. 7.4.2
2. Regulation..... 2. 2%, max........ (b) Normal Sec. 7.4.3
3. Meas. accuracy. 3. 2%, max........ conditions. Sec. 7.4.5
4. CV accuracy.... 3. 2%, max........ (c) Additional 55 Sec. 7.4.9.
5. Pressure meas. 4. 0.3%, max...... mm Hg pressure
accuracy. 5. 10 mm Hg....... drop to simulate
6. Proper loaded filter.
operation. (d) Barometric
pressure at 600
and 800 mm Hg.
Sec. 53.57 Filter 1. Filter temp 1. 2 [deg]C....... (a) 4-hour Sec. 7.4.8
temperature 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 ?50 W/m2.
Sec. 53.58 Field precision 1. Measurement 1. Pj < 2 [mu]g/m3 (a) 3 collocated Sec. 5.1
test. precision. or RPj < 5%. samplers at 1 Sec. 7.3.5
2. Storage 2. 50 [mu]g max. site for at least Sec. 8
deposition test average weight 10 days;. Sec. 9
for sequential gain/blank filter. (b) PM2.5 conc. > Sec. 10.
samplers. 3 [mu]g/m3.
(c) 24- or 48-hour
samples.
(d) 5- or 10-day
storage period
for inactive
stored filters.
----------------------------------------------------------------------------------------------------------------
[[Page 61295]]
The Following Requirement Is Applicable to Class I 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.
----------------------------------------------------------------------------------------------------------------
0
19. References (1), (2), (3), and (5) in appendix A to subpart E of
part 53 are revised to read as follows:
Appendix A to Subpart E 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, P.O. Box 3005, Milwaukee, WI 53202 (http://qualitypress.asq.org).
(2) American National Standard Quality Systems for Environmental
Data and Technology Programs--Requirements with guidance for use,
ANSI/ASQC E4-2004. Available from American Society for Quality, P.O.
Box 3005, Milwaukee, WI 53202 (http://qualitypress.asq.org).
(3) Quality Assurance Guidance Document 2.12. Monitoring
PM2.5 in Ambient Air Using Designated Reference or Class
I Equivalent Methods. U.S. EPA, National Exposure Research
Laboratory, Research Triangle Park, NC, November 1998 or later
edition. Currently available at http://www.epa.gov/ttn/amtic/pmqainf.html.
* * * * *
(5) Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume IV: Meteorological Measurements. Revised March,
1995. EPA-600/R-94-038d. Available from National Technical
Information Service, Springfield, VA 22161, (800-553-6847, http://www.ntis.gov). NTIS number PB95-199782INZ.
* * * * *
Subpart F--[Amended]
0
20. Section 53.60 is amended by:
0
a. Revising paragraph (b);
0
b. Revising paragraph (c);
0
c. Revising paragraph (d) introductory text; and
0
d. Revising paragraph (f)(4) to read as follows:
Sec. 53.60 General provisions.
* * * * *
(b) A candidate method described in an application for a FRM or FEM
determination 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 FEM in Sec. 53.1.
(c) Any sampler associated with a Class II candidate equivalent
method (Class II sampler) must meet all applicable requirements for FRM
samplers or Class I FEM samplers specified in subpart E of this part,
as appropriate. Except as provided in Sec. 53.3(a)(3), a Class II
PM2.5 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 equivalent method 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.
* * * * *
(f) * * *
(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. 53.63 (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.
* * * * *
0
21. The section heading of Sec. 53.61 is revised to read as follows:
Sec. 53.61 Test conditions.
* * * * *
0
22. Section 53.66 is amended by revising paragraph (e)(2)(iii) to read
as follows:
Sec. 53.66 Test procedure: Volatility test.
* * * * *
(e) * * *
(2) * * *
(iii) Operate the candidate and the reference samplers such that
they simultaneously sample the test aerosol for 2 hours for a candidate
sampler operating at 16.7 L/min or higher, or proportionately longer
for a candidate sampler operating at a lower flow rate.
* * * * *
0
23. Table F-1 to subpart F is revised to read as follows:
[[Page 61296]]
Table F-1 to Subpart F of Part 53.--Performance Specifications for PM2.5
Class II Equivalent Samplers
------------------------------------------------------------------------
Performance test Specifications Acceptance criteria
------------------------------------------------------------------------
Sec. 53.62 Full Tunnel Solid VOAG produced Dp50 2.5 [mu]m 0.2 [mu]m
and 24 km/hr. Numerical Analysis
Results: 95% <= ?
Rc <= ? 105%
Sec. 53.63 Wind Tunnel Liquid VOAG produced Relative Aspiration:
Inlet Aspriation Test. aerosol at 2 km/hr 95% <= ? A <= ?
and 24 km/hr. 105%
Sec. 53.64 Static Evaluation of the Dp50 = 2.5 [mu]m ?
Fractionator Test. fractionator under 0.2 [mu]m Numerical
static conditions. Analysis Results:
95% ? <= Rc ? <=
105%
Sec. 53.65 Loading Test... Loading of the clean Acceptance criteria
candidate under as specified in the
laboratory post-loading
conditions. evaluation test
(Sec. 53.62, Sec.
53.63, or Sec.
53.64)
Sec. 53.66 Volatility Test Polydisperse liquid Regression
aerosol produced by Parameters Slope =
air nebulization of 1 0.1,
A.C.S. reagent Intercept = 0 ? 0.15mg r
99.5% minimum >= 0.97.
purity.
------------------------------------------------------------------------
0
24. In Figure E-1 to subpart F, the figure number ``E-1'' is revised to
read ``F-1.''
PART 58--[AMENDED]
0
25. The authority citation for part 58 is revised to read as follows:
Authority: 42 U.S.C. 7403, 7410, 7601(a), 7611, and 7619.
0
26. Subpart A is revised to read as follows:
Subpart A--General Provisions
Sec.
58.1 Definitions.
58.2 Purpose.
58.3 Applicability.
Subpart A--General Provisions
Sec. 58.1 Definitions.
As used in this part, all terms not defined herein have the meaning
given them in the Act.
Act means the Clean Air Act as amended (42 U.S.C. 7401, et seq.)
Additive and multiplicative bias means the linear regression
intercept and slope of a linear plot fitted to corresponding candidate
and reference method mean measurement data pairs.
Administrator means the Administrator of the Environmental
Protection Agency (EPA) or his or her authorized representative.
Air Quality System (AQS) means EPA's computerized system for
storing and reporting of information relating to ambient air quality
data.
Approved regional method (ARM) means a continuous PM2.5
method that has been approved specifically within a State or local air
monitoring network for purposes of comparison to the NAAQS and to meet
other monitoring objectives.
AQCR means air quality control region.
CO means carbon monoxide.
Combined statistical area (CSA) is defined by the U.S. Office of
Management and Budget as a geographical area consisting of two or more
adjacent Core Based Statistical Areas (CBSA) with employment
interchange of at least 15 percent. Combination is automatic if the
employment interchange is 25 percent and determined by local opinion if
more than 15 but less than 25 percent (http://www.census.gov/population/estimates/metro-city/List6.txt).
Community monitoring zone (CMZ) means an optional averaging area
with established, well defined boundaries, such as county or census
block, within an MPA that has relatively uniform concentrations of
annual PM2.5 as defined by appendix N of part 50 of this
chapter. Two or more community-oriented SLAMS monitors within a CMZ
that meet certain requirements as set forth in appendix N of part 50 of
this chapter may be averaged for making comparisons to the annual
PM2.5 NAAQS.
Core-based statistical area (CBSA) is defined by the U.S. Office of
Management and Budget, as a statistical geographic entity consisting of
the county or counties associated with at least one urbanized area/
urban cluster of at least 10,000 population, plus adjacent counties
having a high degree of social and economic integration. Metropolitan
Statistical Areas (MSAs) and micropolitan statistical areas are the two
categories of CBSA (metropolitan areas have populations greater than
50,000; and micropolitan areas have populations between 10,000 and
50,000). In the case of very large cities where two or more CBSAs are
combined, these larger areas are referred to as combined statistical
areas (CSAs) (http://www.census.gov/population/estimates/metro-city/List1.txt).
Corrected concentration pertains to the result of an accuracy or
precision assessment test of an open path analyzer in which a high-
concentration test or audit standard gas contained in a short test cell
is inserted into the optical measurement beam of the instrument. When
the pollutant concentration measured by the analyzer in such a test
includes both the pollutant concentration in the test cell and the
concentration in the atmosphere, the atmospheric pollutant
concentration must be subtracted from the test measurement to obtain
the corrected concentration test result. The corrected concentration is
equal to the measured concentration minus the average of the
atmospheric pollutant concentrations measured (without the test cell)
immediately before and immediately after the test.
Design value means the calculated concentration according to the
applicable appendix of part 50 of this chapter for the highest site in
an attainment or nonattainment area.
EDO means environmental data operations.
Effective concentration pertains to testing an open path analyzer
with a high-concentration calibration or audit standard gas contained
in a short test cell inserted into the optical measurement beam of the
instrument. Effective concentration is the equivalent ambient-level
concentration that would produce the same spectral absorbance over the
actual atmospheric monitoring path length as produced by the high-
concentration gas in the short test cell. Quantitatively, effective
concentration is equal to the actual concentration of the gas standard
in the test cell multiplied by the ratio of the path length of the test
cell to the actual atmospheric monitoring path length.
Federal equivalent method (FEM) 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 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.
Federal reference method (FRM) means a method of sampling and
[[Page 61297]]
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 of this chapter.
HNO3 means nitric acid.
Local agency means any local government agency, other than the
State agency, which is charged by a State with the responsibility for
carrying out a portion of the plan.
Meteorological measurements means measurements of wind speed, wind
direction, barometric pressure, temperature, relative humidity, solar
radiation, ultraviolet radiation, and/or precipitation.
Metropolitan Statistical Area (MSA) means a CBSA associated with at
least one urbanized area of 50,000 population or greater. The central
county plus adjacent counties with a high degree of integration
comprise the area.
Monitor means an instrument, sampler, analyzer, or other device
that measures or assists in the measurement of atmospheric air
pollutants and which is acceptable for use in ambient air surveillance
under the applicable provisions of appendix C to this part.
Monitoring agency means a State or local agency responsible for
meeting the requirements of this part.
Monitoring organization means a State, local, or other monitoring
organization responsible for operating a monitoring site for which the
quality assurance regulations apply.
Monitoring path for an open path analyzer means the actual path in
space between two geographical locations over which the pollutant
concentration is measured and averaged.
Monitoring path length of an open path analyzer means the length of
the monitoring path in the atmosphere over which the average pollutant
concentration measurement (path-averaged concentration) is determined.
See also, optical measurement path length.
Monitoring planning area (MPA) means a contiguous geographic area
with established, well defined boundaries, such as a CBSA, county or
State, having a common area that is used for planning monitoring
locations for PM2.5. An MPA may cross State boundaries, such
as the Philadelphia PA-NJ MSA, and be further subdivided into community
monitoring zones. MPAs are generally oriented toward CBSAs or CSAs with
populations greater than 200,000, but for convenience, those portions
of a State that are not associated with CBSAs can be considered as a
single MPA.
NATTS means the national air toxics trends stations. This network
provides hazardous air pollution ambient data.
NCore means the National Core multipollutant monitoring stations.
Monitors at these sites are required to measure particles
(PM2.5, speciated PM2.5, PM10-2.5),
O3, SO2, CO, nitrogen oxides (NO/NO2/
NOy), Pb, and basic meteorology.
Network means all stations of a given type or types.
NH3 means ammonia.
NO2 means nitrogen dioxide. NO means nitrogen oxide. NOX
means oxides of nitrogen and is defined as the sum of the
concentrations of NO2 and NO.
NOy means the sum of all total reactive nitrogen oxides, including
NO, NO2, and other nitrogen oxides referred to as
NOZ.
O3 means ozone.
Open path analyzer means an automated analytical method that
measures the average atmospheric pollutant concentration in situ along
one or more monitoring paths having a monitoring path length of 5
meters or more and that has been designated as a reference or
equivalent method under the provisions of part 53 of this chapter.
Optical measurement path length means the actual length of the
optical beam over which measurement of the pollutant is determined. The
path-integrated pollutant concentration measured by the analyzer is
divided by the optical measurement path length to determine the path-
averaged concentration. Generally, the optical measurement path length
is:
(1) Equal to the monitoring path length for a (bistatic) system
having a transmitter and a receiver at opposite ends of the monitoring
path;
(2) Equal to twice the monitoring path length for a (monostatic)
system having a transmitter and receiver at one end of the monitoring
path and a mirror or retroreflector at the other end; or
(3) Equal to some multiple of the monitoring path length for more
complex systems having multiple passes of the measurement beam through
the monitoring path.
PAMS means photochemical assessment monitoring stations.
Pb means lead.
Plan means an implementation plan approved or promulgated pursuant
to section 110 of the Act.
PM means PM10, PM110C, PM2.5,
PM10-2.5, or particulate matter of unspecified size range.
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 appendix L of part 50 of this chapter and designated in
accordance with part 53 of this chapter, by an equivalent method
designated in accordance with part 53 of this chapter, or by an
approved regional method designated in accordance with appendix C to
this part.
PM10 means particulate matter with an aerodynamic diameter less
than or equal to a nominal 10 micrometers as measured by a reference
method based on appendix J of part 50 of this chapter and designated in
accordance with part 53 of this chapter or by an equivalent method
designated in accordance with part 53 of this chapter.
PM10C means particulate matter with an aerodynamic diameter less
than or equal to a nominal 10 micrometers as measured by a reference
method based on appendix O of part 50 of this chapter and designated in
accordance with part 53 of this chapter or by an equivalent method
designated in accordance with part 53 of this chapter.
PM10-2.5 means particulate matter with an aerodynamic
diameter less than or equal to a nominal 10 micrometers and greater
than a nominal 2.5 micrometers as measured by a reference method based
on appendix O to part 50 of this chapter and designated in accordance
with part 53 of this chapter or by an equivalent method designated in
accordance with part 53 of this chapter.
Point analyzer means an automated analytical method that measures
pollutant concentration in an ambient air sample extracted from the
atmosphere at a specific inlet probe point and that has been designated
as a reference or equivalent method in accordance with part 53 of this
chapter.
Population-oriented monitoring (or sites) means residential areas,
commercial areas, recreational areas, industrial areas where workers
from more than one company are located, and other areas where a
substantial number of people may spend a significant fraction of their
day.
Primary quality assurance organization means a monitoring
organization or other organization that is responsible for a set of
stations that monitor the same pollutant and for which data quality
assessments can be pooled. Each criteria pollutant sampler/monitor at a
monitoring station in the SLAMS and SPM networks must be associated
with one, and only one, primary quality assurance organization.
Probe means the actual inlet where an air sample is extracted from
the atmosphere for delivery to a sampler or point analyzer for
pollutant analysis.
[[Page 61298]]
PSD station means any station operated for the purpose of
establishing the effect on air quality of the emissions from a proposed
source for purposes of prevention of significant deterioration as
required by Sec. 51.24(n) of this chapter.
Regional Administrator means the Administrator of one of the ten
EPA Regional Offices or his or her authorized representative.
Reporting organization means an entity, such as a State, local, or
Tribal monitoring agency, that collects and reports air quality data to
EPA.
Site means a geographic location. One or more stations may be at
the same site.
SLAMS means State or local air monitoring stations. The SLAMS make
up the ambient air quality monitoring sites that are primarily needed
for NAAQS comparisons, but may serve other data purposes. SLAMS exclude
special purpose monitor (SPM) stations and include NCore, PAMS, and all
other State or locally operated stations that have not been designated
as SPM stations.
SO2 means sulfur dioxide.
Special purpose monitor (SPM) station means a monitor included in
an agency's monitoring network that the agency has designated as a
special purpose monitor station in its monitoring network plan and in
the Air Quality System, and which the agency does not count when
showing compliance with the minimum requirements of this subpart for
the number and siting of monitors of various types.
State agency means the air pollution control agency primarily
responsible for development and implementation of a plan under the Act.
State speciation site means a supplemental PM2.5
speciation station that is not part of the speciation trends network.
Station means a single monitor, or a group of monitors with a
shared objective, located at a particular site.
STN station means a PM2.5 speciation station designated
to be part of the speciation trends network. This network provides
chemical species data of fine particulate.
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).
TSP (total suspended particulates) means particulate matter as
measured by the method described in appendix B of part 50 of this
chapter.
Urbanized area means an area with a minimum residential population
of at least 50,000 people and which generally includes core census
block groups or blocks that have a population density of at least 1,000
people per square mile and surrounding census blocks that have an
overall density of at least 500 people per square mile. The Census
Bureau notes that under certain conditions, less densely settled
territory may be part of each Urbanized Area.
VOC means volatile organic compounds.
Sec. 58.2 Purpose.
(a) This part contains requirements for measuring ambient air
quality and for reporting ambient air quality data and related
information. The monitoring criteria pertain to the following areas:
(1) Quality assurance procedures for monitor operation and data
handling.
(2) Methodology used in monitoring stations.
(3) Operating schedule.
(4) Siting parameters for instruments or instrument probes.
(5) Minimum ambient air quality monitoring network requirements
used to provide support to the State implementation plans (SIP),
national air quality assessments, and policy decisions. These minimums
are described as part of the network design requirements, including
minimum numbers and placement of monitors of each type.
(6) Air quality data reporting, and requirements for the daily
reporting of an index of ambient air quality.
(b) The requirements pertaining to provisions for an air quality
surveillance system in the SIP are contained in this part.
(c) This part also acts to establish a national ambient air quality
monitoring network for the purpose of providing timely air quality data
upon which to base national assessments and policy decisions.
Sec. 58.3 Applicability.
This part applies to:
(a) State air pollution control agencies.
(b) Any local air pollution control agency to which the State has
delegated authority to operate a portion of the State's SLAMS network.
(c) Owners or operators of proposed sources.
0
27. Subpart B is revised to read as follows:
Subpart B--Monitoring Network
Sec.
58.10 Annual monitoring network plan and periodic network
assessment.
58.11 Network technical requirements.
58.12 Operating schedules.
58.13 Monitoring network completion.
58.14 System modification.
58.15 Annual air monitoring data certification.
58.16 Data submittal and archiving requirements.
Subpart B--Monitoring Network
Sec. 58.10 Annual monitoring network plan and periodic network
assessment.
(a)(1) Beginning July 1, 2007, the State, or where applicable
local, agency shall adopt and submit to the Regional Administrator an
annual monitoring network plan which shall provide for the
establishment and maintenance of an air quality surveillance system
that consists of a network of SLAMS monitoring stations including FRM,
FEM, and ARM monitors that are part of SLAMS, NCore stations, STN
stations, State speciation stations, SPM stations, and/or, in serious,
severe and extreme ozone nonattainment areas, PAMS stations, and SPM
monitoring stations. The plan shall include a statement of purposes for
each monitor and evidence that siting and operation of each monitor
meets the requirements of appendices A, C, D, and E of this part, where
applicable. The annual monitoring network plan must be made available
for public inspection for at least 30 days prior to submission to EPA.
(2) Any annual monitoring network plan that proposes SLAMS network
modifications including new monitoring sites is subject to the approval
of the EPA Regional Administrator, who shall provide opportunity for
public comment and shall approve or disapprove the plan and schedule
within 120 days. If the State or local agency has already provided a
public comment opportunity on its plan and has made no changes
subsequent to that comment opportunity, the Regional Administrator is
not required to provide a separate opportunity for comment.
(3) The plan for establishing required NCore multipollutant
stations shall be submitted to the Administrator not later than July 1,
2009. The plan shall provide for all required stations to be
operational by January 1, 2011.
(b) The annual monitoring network plan must contain the following
information for each existing and proposed site:
(1) The AQS site identification number.
(2) The location, including street address and geographical
coordinates.
[[Page 61299]]
(3) The sampling and analysis method(s) for each measured
parameter.
(4) The operating schedules for each monitor.
(5) Any proposals to remove or move a monitoring station within a
period of 18 months following plan submittal.
(6) The monitoring objective and spatial scale of
representativeness for each monitor as defined in appendix D to this
part.
(7) The identification of any sites that are suitable and sites
that are not suitable for comparison against the annual
PM2.5 NAAQS as described in Sec. 58.30.
(8) The MSA, CBSA, CSA or other area represented by the monitor.
(c) The annual monitoring network plan must document how States and
local agencies provide for the review of changes to a PM2.5
monitoring network that impact the location of a violating
PM2.5 monitor or the creation/change to a community
monitoring zone, including a description of the proposed use of spatial
averaging for purposes of making comparisons to the annual
PM2.5 NAAQS as set forth in appendix N to part 50 of this
chapter. The affected State or local agency must document the process
for obtaining public comment and include any comments received through
the public notification process within their submitted plan.
(d) The State, or where applicable local, agency shall perform and
submit to the EPA Regional Administrator an assessment of the air
quality surveillance system every 5 years to determine, at a minimum,
if the network meets the monitoring objectives defined in appendix D to
this part, whether new sites are needed, whether existing sites are no
longer needed and can be terminated, and whether new technologies are
appropriate for incorporation into the ambient air monitoring network.
The network assessment must consider the ability of existing and
proposed sites to support air quality characterization for areas with
relatively high populations of susceptible individuals (e.g., children
with asthma), and, for any sites that are being proposed for
discontinuance, the effect on data users other than the agency itself,
such as nearby States and Tribes or health effects studies. For
PM2.5, the assessment also must identify needed changes to
population-oriented sites. The State, or where applicable local, agency
must submit a copy of this 5-year assessment, along with a revised
annual network plan, to the Regional Administrator. The first
assessment is due July 1, 2010.
(e) All proposed additions and discontinuations of SLAMS monitors
in annual monitoring network plans and periodic network assessments are
subject to approval according to Sec. 58.14.
Sec. 58.11 Network technical requirements.
(a)(1) State and local governments shall follow the applicable
quality assurance criteria contained in appendix A to this part when
operating the SLAMS networks.
(2) Beginning January 1, 2009, State and local governments shall
follow the quality assurance criteria contained in appendix A to this
part that apply to SPM sites when operating any SPM site which uses a
FRM, FEM, or ARM and meets the requirements of appendix E to this part,
unless the Regional Administrator approves an alternative to the
requirements of appendix A with respect to such SPM sites because
meeting those requirements would be physically and/or financially
impractical due to physical conditions at the monitoring site and the
requirements are not essential to achieving the intended data
objectives of the SPM site. Alternatives to the requirements of
appendix A may be approved for an SPM site as part of the approval of
the annual monitoring plan, or separately.
(3) The owner or operator of an existing or a proposed source shall
follow the quality assurance criteria in appendix A to this part that
apply to PSD monitoring when operating a PSD site.
(b) State and local governments must follow the criteria in
appendix C to this part to determine acceptable monitoring methods or
instruments for use in SLAMS networks. Appendix C criteria are optional
at SPM stations.
(c) State and local governments must follow the network design
criteria contained in appendix D to this part in designing and
maintaining the SLAMS stations. The final network design and all
changes in design are subject to approval of the Regional
Administrator. NCore, STN, and PAMS network design and changes are also
subject to approval of the Administrator. Changes in SPM stations do
not require approvals, but a change in the designation of a monitoring
site from SLAMS to SPM requires approval of the Regional Administrator.
(d) State and local governments must follow the criteria contained
in appendix E to this part for siting monitor inlets, paths or probes
at SLAMS stations. Appendix E adherence is optional for SPM stations.
Sec. 58.12 Operating schedules.
State and local governments shall collect ambient air quality data
at any SLAMS station on the following operational schedules:
(a) For continuous analyzers, consecutive hourly averages must be
collected except during:
(1) Periods of routine maintenance,
(2) Periods of instrument calibration, or
(3) Periods or monitoring seasons exempted by the Regional
Administrator.
(b) For Pb manual methods, at least one 24-hour sample must be
collected every 6 days except during periods or seasons exempted by the
Regional Administrator.
(c) For PAMS VOC samplers, samples must be collected as specified
in section 5 of appendix D to this part. Area-specific PAMS operating
schedules must be included as part of the PAMS network description and
must be approved by the Regional Administrator.
(d) For manual PM2.5 samplers:
(1) Manual PM2.5 samplers at SLAMS stations other than
NCore stations must operate on at least a 1-in-3 day schedule at sites
without a collocated continuously operating PM2.5 monitor.
For SLAMS PM2.5 sites with both manual and continuous
PM2.5 monitors operating, the monitoring agency may request
approval for a reduction to 1-in-6 day PM2.5 sampling at
SLAMS stations or for seasonal sampling from the EPA Regional
Administrator. The EPA Regional Administrator may grant sampling
frequency reductions after consideration of factors, including but not
limited to the historical PM2.5 data quality assessments,
the location of current PM2.5 design value sites, and their
regulatory data needs. Sites that have design values that are within
plus or minus 10 percent of the NAAQS; and sites where the 24-hour
values exceed the NAAQS for a period of 3 years are required to
maintain at least a 1-in-3 day sampling frequency. Sites that have a
design value within plus or minus 5 percent of the daily
PM2.5 NAAQS must have an FRM or FEM operate on a daily
schedule.
(2) Manual PM2.5 samplers at NCore stations and required
regional background and regional transport sites must operate on at
least a 1-in-3 day sampling frequency.
(3) Manual PM2.5 speciation samplers at STN stations
must operate on a 1-in-3 day sampling frequency.
(e) For PM10 samplers'a 24-hour sample must be taken
from midnight to midnight (local time) to ensure national consistency.
The minimum monitoring schedule for the site in the area of expected
maximum concentration shall be based on the relative level of that
[[Page 61300]]
monitoring site concentration with respect to the 24-hour standard as
illustrated in Figure 1. If the operating agency demonstrates by
monitoring data that during certain periods of the year conditions
preclude violation of the PM10 24-hour standard, the
increased sampling frequency for those periods or seasons may be
exempted by the Regional Administrator and permitted to revert back to
once in six days. The minimum sampling schedule for all other sites in
the area remains once every six days. No less frequently than as part
of each 5-year network assessment, the most recent year of data must be
considered to estimate the air quality status at the site near the area
of maximum concentration. Statistical models such as analysis of
concentration frequency distributions as described in ``Guideline for
the Interpretation of Ozone Air Quality Standards,'' EPA-450/479-003,
U.S. Environmental Protection Agency, Research Triangle Park, NC,
January 1979, should be used. Adjustments to the monitoring schedule
must be made on the basis of the 5-year network assessment. The site
having the highest concentration in the most current year must be given
first consideration when selecting the site for the more frequent
sampling schedule. Other factors such as major change in sources of
PM10 emissions or in sampling site characteristics could
influence the location of the expected maximum concentration site.
Also, the use of the most recent 3 years of data might, in some cases,
be justified in order to provide a more representative database from
which to estimate current air quality status and to provide stability
to the network. This multiyear consideration reduces the possibility of
an anomalous year biasing a site selected for accelerated sampling. If
the maximum concentration site based on the most current year is not
selected for the more frequent operating schedule, documentation of the
justification for selection of an alternative site must be submitted to
the Regional Office for approval during the 5-year network assessment
process. Minimum data completeness criteria, number of years of data
and sampling frequency for judging attainment of the NAAQS are
discussed in appendix K of part 50 of this chapter.
[GRAPHIC] [TIFF OMITTED] TR17OC06.060
(f) For manual PM10-2.5 samplers:
(1) Manual PM10-2.5 samplers at NCore stations must
operate on at least a 1-in-3 day schedule at sites without a collocated
continuously operating federal equivalent PM10-2.5 method
that has been designated in accordance with part 53 of this chapter.
(2) Manual PM10-2.5 speciation samplers at NCore
stations must operate on at least a 1-in-3 day sampling frequency.
Sec. 58.13 Monitoring network completion.
(a) The network of NCore multipollutant sites must be physically
established no later than January 1, 2011, and at that time, operating
under all of the requirements of this part, including the requirements
of appendices A, C, D, E, and G to this part.
(b) Where existing networks are not in conformance with required
numbers of monitors specified in this part, additional required
monitors must be operated by January 1, 2008.
Sec. 58.14 System modification.
(a) The State, or where appropriate local, agency shall develop and
implement a plan and schedule to modify the ambient air quality
monitoring network that complies with the findings of the network
assessments required every 5 years by Sec. 58.10(e). The State or
local agency shall consult with the EPA Regional Administrator during
the development of the schedule to modify the monitoring program, and
shall make the plan and schedule available to the public for 30 days
prior to submission to the EPA Regional Administrator. The final plan
and schedule with respect to the SLAMS network are subject to the
approval of the EPA Regional Administrator. Plans containing
modifications to NCore Stations or PAMS Stations shall be submitted to
the Administrator. The Regional Administrator shall provide opportunity
for public comment and shall approve or disapprove submitted plans and
schedules within 120 days.
(b) Nothing in this section shall preclude the State, or where
appropriate local, agency from making modifications to the SLAMS
network for reasons other than those resulting from the periodic
network assessments. These modifications must be reviewed and
[[Page 61301]]
approved by the Regional Administrator. Each monitoring network may
make or be required to make changes between the 5-year assessment
periods, including for example, site relocations or the addition of
PAMS networks in bumped-up ozone nonattainment areas. These
modifications must address changes invoked by a new census and changes
due to changing air quality levels. The State, or where appropriate
local, agency shall provide written communication describing the
network changes to the Regional Administrator for review and approval
as these changes are identified.
(c) State, or where appropriate, local agency requests for SLAMS
monitor station discontinuation, subject to the review of the Regional
Administrator, will be approved if any of the following criteria are
met and if the requirements of appendix D to this part, if any,
continue to be met. Other requests for discontinuation may also be
approved on a case-by-case basis if discontinuance does not compromise
data collection needed for implementation of a NAAQS and if the
requirements of appendix D to this part, if any, continue to be met.
(1) Any PM2.5, O3, CO, PM10,
SO2, Pb, or NO2 SLAMS monitor which has shown
attainment during the previous five years, that has a probability of
less than 10 percent of exceeding 80 percent of the applicable NAAQS
during the next three years based on the levels, trends, and
variability observed in the past, and which is not specifically
required by an attainment plan or maintenance plan. In a nonattainment
or maintenance area, if the most recent attainment or maintenance plan
adopted by the State and approved by EPA contains a contingency measure
to be triggered by an air quality concentration and the monitor to be
discontinued is the only SLAMS monitor operating in the nonattainment
or maintenance area, the monitor may not be discontinued.
(2) Any SLAMS monitor for CO, PM10, SO2, or
NO2 which has consistently measured lower concentrations
than another monitor for the same pollutant in the same county (or
portion of a county within a distinct attainment area, nonattainment
area, or maintenance area, as applicable) during the previous five
years, and which is not specifically required by an attainment plan or
maintenance plan, if control measures scheduled to be implemented or
discontinued during the next five years would apply to the areas around
both monitors and have similar effects on measured concentrations, such
that the retained monitor would remain the higher reading of the two
monitors being compared.
(3) For any pollutant, any SLAMS monitor in a county (or portion of
a county within a distinct attainment, nonattainment, or maintenance
area, as applicable) provided the monitor has not measured violations
of the applicable NAAQS in the previous five years, and the approved
SIP provides for a specific, reproducible approach to representing the
air quality of the affected county in the absence of actual monitoring
data.
(4) A PM2.5 SLAMS monitor which EPA has determined
cannot be compared to the relevant NAAQS because of the siting of the
monitor, in accordance with Sec. 58.30.
(5) A SLAMS monitor that is designed to measure concentrations
upwind of an urban area for purposes of characterizing transport into
the area and that has not recorded violations of the relevant NAAQS in
the previous five years, if discontinuation of the monitor is tied to
start-up of another station also characterizing transport.
(6) A SLAMS monitor not eligible for removal under any of the
criteria in paragraphs (c)(1) through (c)(5) of this section may be
moved to a nearby location with the same scale of representation if
logistical problems beyond the State's control make it impossible to
continue operation at its current site.
Sec. 58.15 Annual air monitoring data certification.
(a) The State, or where appropriate local, agency shall submit to
the EPA Regional Administrator an annual air monitoring data
certification letter to certify data collected at all SLAMS and at all
FRM, FEM, and ARM SPM stations that meet criteria in appendix A to this
part from January 1 to December 31 of the previous year. The senior air
pollution control officer in each agency, or his or her designee, shall
certify that the previous year of ambient concentration and quality
assurance data are completely submitted to AQS and that the ambient
concentration data are accurate to the best of her or his knowledge,
taking into consideration the quality assurance findings.
(1) Through 2009, the annual data certification letter is due by
July 1 of each year.
(2) Beginning in 2010, the annual data certification letter is due
by May 1 of each year.
(b) Along with each certification letter, the State shall submit to
the Administrator (through the appropriate Regional Office) an annual
summary report of all the ambient air quality data collected at all
SLAMS and at SPM stations using FRM, FEM, or ARMs. The annual report(s)
shall be submitted for data collected from January 1 to December 31 of
the previous year. The annual summary report(s) must contain all
information and data required by the State's approved plan and must be
submitted on the same schedule as the certification letter, unless an
approved alternative date is included in the plan. The annual summary
serves as the record of the specific data that is the object of the
certification letter.
(c) Along with each certification letter, the State shall submit to
the Administrator (through the appropriate Regional Office) a summary
of the precision and accuracy data for all ambient air quality data
collected at all SLAMS and at SPM stations using FRM, FEM, or ARMs. The
summary of precision and accuracy shall be submitted for data collected
from January 1 to December 31 of the previous year. The summary of
precision and accuracy must be submitted on the same schedule as the
certification letter, unless an approved alternative date is included
in the plan.
Sec. 58.16 Data submittal and archiving requirements.
(a) The State, or where appropriate, local agency, shall report to
the Administrator, via AQS all ambient air quality data and associated
quality assurance data for SO2; CO; O3;
NO2; NO; NOY; NOX; Pb; PM10
mass concentration; PM2.5 mass concentration; for filter-
based PM2.5 FRM/FEM the field blank mass, sampler-generated
average daily temperature, and sampler-generated average daily
pressure; chemically speciated PM2.5 mass concentration
data; PM10-2.5 mass concentration; chemically speciated
PM10-2.5 mass concentration data; meteorological data from
NCore and PAMS sites; and metadata records and information specified by
the AQS Data Coding Manual (http://www.epa.gov/ttn/airs/airsaqs/manuals/manuals.htm). Such air quality data and information must be
submitted directly to the AQS via electronic transmission on the
specified quarterly schedule described in paragraph (b) of this
section.
(b) The specific quarterly reporting periods are January 1-March
31, April 1-June 30, July 1-September 30, and October 1-December 31.
The data and information reported for each reporting period must
contain all data and information gathered during the reporting period,
and be received in the AQS within 90 days after the end of the
quarterly reporting period. For example,
[[Page 61302]]
the data for the reporting period January 1-March 31 are due on or
before June 30 of that year.
(c) Air quality data submitted for each reporting period must be
edited, validated, and entered into the AQS (within the time limits
specified in paragraph (b) of this section) pursuant to appropriate AQS
procedures. The procedures for editing and validating data are
described in the AQS Data Coding Manual and in each monitoring agency's
quality assurance project plan.
(d) The State shall report VOC and if collected, carbonyl,
NH3, and HNO3 data, from PAMS sites to AQS within
6 months following the end of each quarterly reporting period listed in
paragraph (b) of this section.
(e) The State shall also submit any portion or all of the SLAMS and
SPM data to the appropriate Regional Administrator upon request.
(f) The State, or where applicable, local agency shall archive all
PM2.5, PM10, and PM10-2.5 filters from
manual low-volume samplers (samplers having flow rates less than 200
liters/minute) from all SLAMS sites for a minimum period of 1 year
after collection. These filters shall be made available during the
course of that year for supplemental analyses at the request of EPA or
to provide information to State and local agencies on particulate
matter composition. Other Federal agencies may request access to
filters for purposes of supporting air quality management or community
health--such as biological assay--through the applicable EPA Regional
Administrator. The filters shall be archived according to procedures
approved by the Administrator. The EPA recommends that particulate
matter filters be archived for longer periods, especially for key sites
in making NAAQS related decisions or for supporting health-related air
pollution studies.
0
28. Subpart C is revised to read as follows:
Subpart C--Special Purpose Monitors
Sec. 58.20 Special purpose monitors (SPM).
(a) An SPM is defined as any monitor included in an agency's
monitoring network that the agency has designated as a special purpose
monitor in its annual monitoring network plan and in AQS, and which the
agency does not count when showing compliance with the minimum
requirements of this subpart for the number and siting of monitors of
various types. Any SPM operated by an air monitoring agency must be
included in the periodic assessments and annual monitoring network plan
required by Sec. 58.10. The plan shall include a statement of purposes
for each SPM monitor and evidence that operation of each monitor meets
the requirements of appendix A or an approved alternative as provided
by Sec. 58.11(a)(2) where applicable. The monitoring agency may
designate a monitor as an SPM after January 1, 2007 only if it is a new
monitor, i.e., a SLAMS monitor that is not included in the currently
applicable monitoring plan or, for a monitor included in the monitoring
plan prior to January 1, 2007, if the Regional Administrator has
approved the discontinuation of the monitor as a SLAMS site.
(b) Any SPM data collected by an air monitoring agency using a
Federal reference method (FRM), Federal equivalent method (FEM), or
approved regional method (ARM) must meet the requirements of Sec.
58.11, Sec. 58.12, and appendix A to this part or an approved
alternative to appendix A to this part. Compliance with appendix E to
this part is optional but encouraged except when the monitoring
agency's data objectives are inconsistent with those requirements. Data
collected at an SPM using a FRM, FEM, or ARM meeting the requirements
of appendix A must be submitted to AQS according to the requirements of
Sec. 58.16. Data collected by other SPMs may be submitted. The
monitoring agency must also submit to AQS an indication of whether each
SPM reporting data to AQS monitor meets the requirements of appendices
A and E to this part.
(c) All data from an SPM using an FRM, FEM, or ARM which has
operated for more than 24 months is eligible for comparison to the
relevant NAAQS, subject to the conditions of Sec. 58.30, unless the
air monitoring agency demonstrates that the data came from a particular
period during which the requirements of appendix A or an approved
alternative, appendix C, or appendix E were not met in practice.
(d) If an SPM using an FRM, FEM, or ARM is discontinued within 24
months of start-up, the Administrator will not base a NAAQS violation
determination for the PM2.5 or ozone NAAQS solely on data
from the SPM.
(e) If an SPM using an FRM, FEM, or ARM is discontinued within 24
months of start-up, the Administrator will not designate an area as
nonattainment for the CO, SO2, NO2, Pb, or 24-
hour PM10 NAAQS solely on the basis of data from the SPM.
Such data are eligible for use in determinations of whether a
nonattainment area has attained one of these NAAQS.
(f) Prior approval from EPA is not required for discontinuance of
an SPM.
0
29. Subpart D is revised to read as follows:
Subpart D--Comparability of Ambient Data to NAAQS
Sec. 58.30 Special considerations for data comparisons to the NAAQS.
(a) Comparability of PM2.5 data. (1) There are two forms of the
PM2.5 NAAQS described in part 50 of this chapter. The
PM2.5 monitoring site characteristics (see appendix D to
this part, section 4.7.1) impact how the resulting PM2.5
data can be compared to the annual PM2.5 NAAQS form.
PM2.5 data that are representative, not of areawide 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 to the 24-hour PM2.5
NAAQS. For example, if the PM2.5 monitoring site is adjacent
to a unique dominating local PM2.5 source or can be shown to
have average 24-hour concentrations representative of a smaller than
neighborhood spatial scale, then data from a monitor at the site would
only be eligible for comparison to the 24-hour PM2.5 NAAQS.
(2) There are cases where certain population-oriented microscale or
middle scale PM2.5 monitoring sites are determined by the
Regional Administrator to collectively identify a larger region of
localized high ambient PM2.5 concentrations. In those cases,
data from these population-oriented sites would be eligible for
comparison to the annual PM2.5 NAAQS.
(b) [Reserved]
Subpart E--[Removed and Reserved]
0
30. Subpart E of part 58 is removed and reserved.
Subpart F--[Amended]
0
31. Section 58.50 is revised to read as follows:
Sec. 58.50 Index reporting.
(a) The State or where applicable, local agency shall report to the
general public on a daily basis through prominent notice an air quality
index that complies with the requirements of appendix G to this part.
(b) Reporting is required for all individual MSA with a population
exceeding 350,000.
(c) The population of a MSA for purposes of index reporting is the
most recent decennial U.S. census population.
[[Page 61303]]
Subpart G--[Amended]
0
32. Sections 58.60 and 58.61 are revised to read as follows:
Sec. 58.60 Federal monitoring.
The Administrator may locate and operate an ambient air monitoring
site if the State or local agency fails to locate, or schedule to be
located, during the initial network design process, or as a result of
the 5-year network assessments required in Sec. 58.10, a SLAMS station
at a site which is necessary in the judgment of the Regional
Administrator to meet the objectives defined in appendix D to this
part.
Sec. 58.61 Monitoring other pollutants.
The Administrator may promulgate criteria similar to that
referenced in subpart B of this part for monitoring a pollutant for
which an NAAQS does not exist. Such an action would be taken whenever
the Administrator determines that a nationwide monitoring program is
necessary to monitor such a pollutant.
0
33. Appendix A to part 58 is revised to read as follows:
Appendix A to Part 58--Quality Assurance Requirements for SLAMS, SPMs
and PSD Air Monitoring
1. General Information
2. Quality System Requirements
3. Measurement Quality Check Requirements
4. Calculations for Data Quality Assessments
5. Reporting Requirements
6. References
1. General Information
This appendix specifies the minimum quality system requirements
applicable to SLAMS air monitoring data and PSD data for the
pollutants SO2, NO2, O3, CO,
PM2.5, PM10 and PM10-2.5 submitted
to EPA. This appendix also applies to all SPM stations using FRM,
FEM, or ARM methods which also meet the requirements of Appendix E
of this part. Monitoring organizations are encouraged to develop and
maintain quality systems more extensive than the required minimums.
The permit-granting authority for PSD may require more frequent or
more stringent requirements. Monitoring organizations may, based on
their quality objectives, develop and maintain quality systems
beyond the required minimum. Additional guidance for the
requirements reflected in this appendix can be found in the
``Quality Assurance Handbook for Air Pollution Measurement
Systems'', volume II, part 1 (see reference 10 of this appendix) and
at a national level in references 1, 2, and 3 of this appendix.
1.1 Similarities and Differences Between SLAMS and PSD
Monitoring. In most cases, the quality assurance requirements for
SLAMS, SPMs if applicable, and PSD are the same. Affected SPMs are
subject to all the SLAMS requirements, even where not specifically
stated in each section. Table A-1 of this appendix summarizes the
major similarities and differences of the requirements for SLAMS and
PSD. Both programs require:
(a) The development, documentation, and implementation of an
approved quality system;
(b) The assessment of data quality;
(c) The use of reference, equivalent, or approved methods. The
requirements of this appendix do not apply to a SPM that does not
use a FRM, FEM, or ARM;
(d) The use of calibration standards traceable to NIST or other
primary standard;
(e) Performance evaluations and systems.
1.1.1 The monitoring and quality assurance responsibilities for
SLAMS are with the State or local agency, hereafter called the
monitoring organization, whereas for PSD they are with the owner/
operator seeking the permit. The monitoring duration for SLAMS is
indefinite, whereas for PSD the duration is usually 12 months.
Whereas the reporting period for precision and accuracy data is on
an annual or calendar quarter basis for SLAMS, it is on a continuing
sampler quarter basis for PSD, since the monitoring may not commence
at the beginning of a calendar quarter.
1.1.2 The annual performance evaluations (described in section
3.2.2 of this appendix) for PSD must be conducted by personnel
different from those who perform routine span checks and
calibrations, whereas for SLAMS, it is the preferred but not the
required condition. For PSD, the evaluation rate is 100 percent of
the sites per reporting quarter whereas for SLAMS it is 25 percent
of the sites or instruments quarterly. Monitoring for sulfur dioxide
(SO2) and nitrogen dioxide (NO2) for PSD must
be done with automated analyzers--the manual bubbler methods are not
permitted.
1.1.3 The requirements for precision assessment for the
automated methods are the same for both SLAMS and PSD. However, for
manual methods, only one collocated site is required for PSD.
1.1.4 The precision, accuracy and bias data for PSD are reported
separately for each sampler (site), whereas for SLAMS, the report
may be by sampler (site), by primary quality assurance organization,
or nationally, depending on the pollutant. SLAMS data are required
to be reported to the AQS, PSD data are required to be reported to
the permit-granting authority. Requirements in this appendix, with
the exception of the differences discussed in this section, and in
Table A-1 of this appendix will be expected to be followed by both
SLAMS and PSD networks unless directly specified in a particular
section.
1.2 Measurement Uncertainty. Measurement uncertainty is a term
used to describe deviations from a true concentration or estimate
that are related to the measurement process and not to spatial or
temporal population attributes of the air being measured. Monitoring
organizations must develop quality assurance project plans (QAPP)
which describe how the organization intends to control measurement
uncertainty to an appropriate level in order to achieve the
objectives for which the data are collected. The process by which
one determines the quality of data needed to meet the monitoring
objective is sometimes referred to the Data Quality Objectives
Process. Data quality indicators associated with measurement
uncertainty include:
(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) Bias. The systematic or persistent distortion of a
measurement process which causes errors in one direction.
(c) Accuracy. The degree of agreement between an observed value
and an accepted reference value. Accuracy includes a combination of
random error (imprecision) and systematic error (bias) components
which are due to sampling and analytical operations.
(d) Completeness. A measure of the amount of valid data obtained
from a measurement system compared to the amount that was expected
to be obtained under correct, normal conditions.
(e) Detectability. The low critical range value of a
characteristic that a method specific procedure can reliably
discern.
1.3 Measurement Quality Checks. The SLAMS measurement quality
checks described in sections 3.2 and 3.3 of this appendix shall be
reported to AQS and are included in the data required for
certification. The PSD network is required to implement the
measurement quality checks and submit this information quarterly
along with assessment information to the permit-granting authority.
1.4 Assessments and Reports. Periodic assessments and
documentation of data quality are required to be reported to EPA or
to the permit granting authority (PSD). To provide national
uniformity in this assessment and reporting of data quality for all
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 quality assurance
and quality control activities used by a monitoring organization
depend on a number of local factors such as field and laboratory
conditions, the objectives for monitoring, the level of data quality
needed, the expertise of assigned personnel, the cost of control
procedures, pollutant concentration levels, etc. Therefore, quality
system requirements in section 2 of this appendix are specified in
general terms to allow each monitoring organization to develop a
quality system that is most efficient and effective for its own
circumstances while achieving the data quality objectives required
for the SLAMS sites.
2. Quality System Requirements
A quality system is the means by which an organization manages
the quality of the monitoring information it produces in a
systematic, organized manner. It provides a framework for planning,
implementing, assessing and reporting work performed by an
organization and for carrying out required quality assurance and
quality control activities.
2.1 Quality Management Plans and Quality Assurance Project
Plans. All
[[Page 61304]]
monitoring organizations must develop a quality system that is
described and approved in quality management plans (QMP) and quality
assurance project plans (QAPP) to ensure that the monitoring
results:
(a) Meet a well-defined need, use, or purpose;
(b) Provide data of adequate quality for the intended monitoring
objectives;
(c) Satisfy stakeholder expectations;
(d) Comply with applicable standards specifications;
(e) Comply with statutory (and other) requirements of society;
and
(f) Reflect consideration of cost and economics.
2.1.1 The QMP describes the quality system in terms of the
organizational structure, functional responsibilities of management
and staff, lines of authority, and required interfaces for those
planning, implementing, assessing and reporting activities involving
environmental data operations (EDO). The QMP must be suitably
documented in accordance with EPA requirements (reference 2 of this
appendix), and approved by the appropriate Regional Administrator,
or his or her representative. The quality system will be reviewed
during the systems audits described in section 2.5 of this appendix.
Organizations that implement long-term monitoring programs with EPA
funds should have a separate QMP document. Smaller organizations or
organizations that do infrequent work with EPA funds may combine the
QMP with the QAPP based on negotiations with the funding agency.
Additional guidance on this process can be found in reference 10 of
this appendix. Approval of the recipient's QMP by the appropriate
Regional Administrator or his or her representative, may allow
delegation of the authority to review and approve the QAPP to the
recipient, based on adequacy of quality assurance procedures
described and documented in the QMP. The QAPP will be reviewed by
EPA during systems audits or circumstances related to data quality.
2.1.2 The QAPP is a formal document describing, in sufficient
detail, the quality system that must be implemented to ensure that
the results of work performed will satisfy the stated objectives.
The quality assurance policy of the EPA requires every environmental
data operation (EDO) to have a written and approved QAPP prior to
the start of the EDO. It is the responsibility of the monitoring
organization to adhere to this policy. The QAPP must be suitably
documented in accordance with EPA requirements (reference 3 of this
appendix).
2.1.3 The monitoring organization's quality system must have
adequate resources both in personnel and funding to plan, implement,
assess and report on the achievement of the requirements of this
appendix and its approved QAPP.
2.2 Independence of Quality Assurance. The monitoring
organization must provide for a quality assurance management
function- that aspect of the overall management system of the
organization that determines and implements the quality policy
defined in a monitoring organization's QMP. Quality management
includes strategic planning, allocation of resources and other
systematic planning activities (e.g., planning, implementation,
assessing and reporting) pertaining to the quality system. The
quality assurance management function must have sufficient technical
expertise and management authority to conduct independent oversight
and assure the implementation of the organization's quality system
relative to the ambient air quality monitoring program and should be
organizationally independent of environmental data generation
activities.
2.3. Data Quality Performance Requirements.
2.3.1 Data Quality Objectives. Data quality objectives (DQO) or
the results of other systematic planning processes are statements
that define the appropriate type of data to collect and specify the
tolerable levels of potential decision errors that will be used as a
basis for establishing the quality and quantity of data needed to
support the objectives of the SLAMS stations. DQO will be developed
by EPA to support the primary SLAMS objectives for each criteria
pollutant. As they are developed they will be added to the
regulation. DQO or the results of other systematic planning
processes for PSD or other monitoring will be the responsibility of
the monitoring organizations. The quality of the conclusions made
from data interpretation can be affected by population uncertainty
(spatial or temporal uncertainty) and measurement uncertainty
(uncertainty associated with collecting, analyzing, reducing and
reporting concentration data). This appendix focuses on assessing
and controlling measurement uncertainty.
2.3.1.1 Measurement Uncertainty for Automated and Manual
PM2.5 Methods. The goal for acceptable measurement
uncertainty is defined as 10 percent coefficient of variation (CV)
for total precision and plus or minus 10 percent for total bias.
2.3.1.2 Measurement Uncertainty for Automated Ozone Methods. The
goal for acceptable measurement uncertainty is defined for precision
as an upper 90 percent confidence limit for the coefficient
variation (CV) of 7 percent and for bias as an upper 95 percent
confidence limit for the absolute bias of 7 percent.
2.3.1.3 Measurement Uncertainty for PM10-2.5 Methods.
The goal for acceptable measurement uncertainty is defined for
precision as an upper 90 percent confidence limit for the
coefficient variation (CV) of 15 percent and for bias as an upper 95
percent confidence limit for the absolute bias of 15 percent.
2.4 National Performance Evaluation Programs. Monitoring plans
or the QAPP shall provide for the implementation of a program of
independent and adequate audits of all monitors providing data for
SLAMS and PSD including the provision of adequate resources for such
audit programs. A monitoring plan (or QAPP) which provides for
monitoring organization participation in EPA's National Performance
Audit Program (NPAP) and the PM Performance Evaluation Program (PEP)
program and which indicates the consent of the monitoring
organization for EPA to apply an appropriate portion of the grant
funds, which EPA would otherwise award to the monitoring
organization for monitoring activities, will be deemed by EPA to
meet this requirement. For clarification and to participate,
monitoring organizations should contact either the appropriate EPA
Regional Quality Assurance (QA) Coordinator at the appropriate EPA
Regional Office location, or the NPAP Coordinator, Emissions
Monitoring and Analysis Division (D205-02), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711.
2.5 Technical Systems Audit Program. Technical systems audits of
each ambient air monitoring organization shall be conducted at least
every 3 years by the appropriate EPA Regional Office and reported to
the AQS. Systems audit programs are described in reference 10 of
this appendix. For further instructions, monitoring organizations
should contact the appropriate EPA Regional QA Coordinator.
2.6 Gaseous and Flow Rate Audit Standards.
2.6.1 Gaseous pollutant concentration standards (permeation
devices or cylinders of compressed gas) used to obtain test
concentrations for carbon monoxide (CO), sulfur dioxide
(SO2), nitrogen oxide (NO), and nitrogen dioxide
(NO2) must be traceable to either a National Institute of
Standards and Technology (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 4 of this appendix. Vendors advertising certification with
the procedures provided in reference 4 of this appendix and
distributing gasses as ``EPA Protocol Gas'' must participate in the
EPA Protocol Gas Verification Program or not use ``EPA'' in any form
of advertising.
2.6.2 Test concentrations for ozone (O3) must be
obtained in accordance with the ultra violet photometric calibration
procedure specified in appendix D to part 50 of this chapter, or by
means of a certified O3 transfer standard. Consult
references 7 and 8 of this appendix for guidance on primary and
transfer standards for O3.
2.6.3 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 10 of this appendix.
2.7 Primary Requirements and Guidance. Requirements and guidance
documents for developing the quality system are contained in
references 1 through 10 of this appendix, which also contain many
suggested procedures, checks, and control specifications. Reference
10 of this appendix describes specific guidance for the development
of a quality system 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 6 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.
[[Page 61305]]
3. Measurement Quality Check Requirements
This section provides the requirements for primary quality
assurance organizations (PQAOs) to perform the measurement quality
checks that can be used to assess data quality. With the exception
of the flow rate verifications (sections 3.2.3 and 3.3.2 of this
appendix), data from these checks are required to be submitted to
the AQS within the same time frame as routine ambient concentration
data. Section 3.2 of this appendix describes checks of automated or
continuous instruments while section 3.3 describe checks associated
with manual sampling instruments. Other quality control samples are
identified in the various references described earlier and can be
used to control certain aspects of the measurement system.
3.1 Primary Quality Assurance Organization. A primary quality
assurance organization is defined as a monitoring organization or a
coordinated aggregation of such organizations that is responsible
for a set of stations that monitors the same pollutant and for which
data quality assessments can logically be pooled. Each criteria
pollutant sampler/monitor at a monitoring station in the SLAMS
network must be associated with one, and only one, primary quality
assurance organization.
3.1.1 Each primary quality assurance 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. Common factors that should be considered
by monitoring organizations in defining primary quality assurance
organizations include:
(a) Operation by a common team of field operators according to a
common set of procedures;
(b) Use of a common QAPP or standard operating procedures;
(c) Common calibration facilities and standards;
(d) Oversight by a common quality assurance organization; and
(e) Support by a common management, laboratory or headquarters.
3.1.2 Primary quality assurance organizations are not
necessarily related to the organization reporting data to the AQS.
Monitoring organizations having difficulty in defining the primary
quality assurance organizations or in assigning specific sites to
primary quality assurance organizations should consult with the
appropriate EPA Regional Office. All definitions of primary quality
assurance organizations shall be subject to final approval by the
appropriate EPA Regional Office during scheduled network reviews or
systems audits.
3.1.3 Data quality assessment results shall be reported as
specified in section 5 of this appendix.
3.2 Measurement Quality Checks of Automated Methods. Table A-2
of this appendix provides a summary of the types and frequency of
the measurement quality checks that will be described in this
section.
3.2.1 One-Point Quality Control Check for SO2,
NO2, O3, and CO. A one-point quality control
(QC) check must be performed at least once every 2 weeks on each
automated analyzer used to measure SO2, NO2,
O3 and CO. The frequency of QC checks may be reduced
based upon review, assessment and approval of the EPA Regional
Administrator. However, with the advent of automated calibration
systems more frequent checking is encouraged. See Reference 10 of
this appendix for guidance on the review procedure. The QC check is
made by challenging the analyzer with a QC check gas of known
concentration (effective concentration for open path analyzers)
between 0.01 and 0.10 parts per million (ppm) for SO2,
NO2, and O3, and between 1 and 10 ppm for CO
analyzers. The ranges allow for appropriate check gas selection for
SLAMS sites that may be sampling for different objectives, i.e.,
trace gas monitoring vs. comparison to National Ambient Air Quality
Standards (NAAQS). The QC check gas concentration selected should be
related to the routine concentrations normally measured at sites
within the monitoring network in order to appropriately reflect the
precision and bias at these routine concentration ranges. To check
the precision and bias of SLAMS analyzers operating at ranges either
above or below the levels identified, use check gases of appropriate
concentrations as approved by the appropriate EPA Regional
Administrator or their designee. The standards from which check
concentrations are obtained must meet the specifications of section
2.6 of this appendix.
3.2.1.1 Except for certain CO analyzers described below, point
analyzers must operate in their normal sampling mode during the QC
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
QC 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 QC check is
made in conjunction with a zero or span adjustment, it must be made
prior to such zero or span adjustments.
3.2.1.2 Open path analyzers are tested by inserting a test cell
containing a QC 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 QC check gas in the test cell must be selected to produce an
effective concentration in the range specified earlier in this
section. Generally, the QC test concentration measurement will be
the sum of the atmospheric pollutant concentration and the QC 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 QC test from the QC
check gas 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.
3.2.1.3 Report the audit concentration (effective concentration
for open path analyzers) of the QC gas and the corresponding
measured concentration (corrected concentration, if applicable, for
open path analyzers) indicated by the analyzer. The percent
differences between these concentrations are used to assess the
precision and bias of the monitoring data as described in sections
4.1.2 (precision) and 4.1.3 (bias) of this appendix.
3.2.2 Annual performance evaluation for SO2,
NO2, O3, or CO. Each calendar quarter (during
which analyzers are operated), evaluate at least 25 percent of the
SLAMS analyzers that monitor for SO2, NO2,
O3, or CO such that each analyzer is evaluated at least
once per year. If there are fewer than four analyzers for a
pollutant within a primary quality assurance organization, it is
suggested to randomly evaluate one or more analyzers so that at
least one analyzer for that pollutant is evaluated each calendar
quarter. The evaluation should be conducted by a trained experienced
technician other than the routine site operator.
3.2.2.1 (a) The evaluation is made by challenging the analyzer
with audit gas standard of known concentration (effective
concentration for open path analyzers) from at least three
consecutive audit levels. The audit levels selected should represent
or bracket 80 percent of ambient concentrations measured by the
analyzer being evaluated:
----------------------------------------------------------------------------------------------------------------
Concentration range, ppm
Audit level ---------------------------------------------------------------------------
O3 SO2 NO2 CO
----------------------------------------------------------------------------------------------------------------
1................................... 0.02-0.05 0.0003-0.005 0.0002-0.002 0.08-0.10
2................................... 0.06-0.10 0.006-0.01 0.003-0.005 0.50-1.00
[[Page 61306]]
3................................... 0.11-0.20 0.02-0.10 0.006-0.10 1.50-4.00
4................................... 0.21-0.30 0.11-0.40 0.11-0.30 5-15
5................................... 0.31-0.90 0.41-0.90 0.31-0.60 20-50
----------------------------------------------------------------------------------------------------------------
(b) An additional 4th level is encouraged for those monitors
that have the potential for exceeding the concentration ranges
described by the initial three selected.
3.2.2.2 (a) NO2 audit gas for chemiluminescence-type
NO2 analyzers must also contain at least 0.08 ppm NO. NO
concentrations substantially higher than 0.08 ppm, as may occur when
using some gas phase titration (GPT) techniques, may lead to
evaluation 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.
(b) To evaluate SLAMS analyzers operating on ranges higher than
0 to 1.0 ppm for SO2, NO2, and O3
or 0 to 50 ppm for CO, use audit gases of appropriately higher
concentration as approved by the appropriate EPA Regional
Administrator or the Administrator's designee.
3.2.2.3 The standards from which audit gas test concentrations
are obtained must meet the specifications of section 2.6 of this
appendix. The gas standards and equipment used for evaluations must
not be the same as the standards and equipment used for calibration
or calibration span adjustments. For SLAMS sites, the auditor should
not be the operator or analyst who conducts the routine monitoring,
calibration, and analysis. For PSD sites the auditor must not be the
operator or analyst who conducts the routine monitoring,
calibration, and analysis.
3.2.2.4 For point analyzers, the evaluation shall be carried out
by allowing the analyzer to analyze the audit gas 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 3.2.1 of this appendix for certain CO analyzers does not
apply for evaluations.
3.2.2.5 Open path analyzers are evaluated 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 evaluation, and the normal
monitoring configuration of the instrument should be modified as
little as possible to accommodate the test cell for the evaluation.
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
evaluation level ranges specified in this section of this appendix.
Generally, each evaluation concentration measurement result will be
the sum of the atmospheric pollutant concentration and the
evaluation 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 evaluation
test (or preferably before and after each evaluation concentration
level) from the evaluation 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
evaluated during periods when the atmospheric pollutant
concentrations are relatively low and steady. Also, if the open path
instrument is not installed in a permanent manner, the monitoring
path length must be reverified to within plus or minus 3 percent to
validate the evaluation, since the monitoring path length is
critical to the determination of the effective concentration.
3.2.2.6 Report both the evaluation concentrations (effective
concentrations for open path analyzers) of the audit gases and the
corresponding measured concentration (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 quality of the monitoring data
as described in section 4.1.4 of this appendix.
3.2.3 Flow Rate Verification for Particulate Matter. A one-point
flow rate verification check must be performed at least once every
month on each automated analyzer used to measure PM10,
PM10-2.5 and PM2.5. The verification is made
by checking the operational flow rate of the analyzer. If the
verification is made in conjunction with a flow rate adjustment, it
must be made prior to such flow rate adjustment. Randomization of
the flow rate verification with respect to time of day, day of week,
and routine service and adjustments is encouraged where possible.
For the standard procedure, use a flow rate transfer standard
certified in accordance with section 2.6 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
flow rate of the transfer standard and the corresponding flow rate
measured (indicated) by the analyzer. The percent differences
between the audit and measured flow rates are used to assess the
bias of the monitoring data as described in section 4.2.2 of this
appendix (using flow rates in lieu of concentrations).
3.2.4 Semi-Annual Flow Rate Audit for Particulate Matter. Every
6 months, audit the flow rate of the PM10,
PM10-2.5 and PM2.5 particulate analyzers.
Where possible, EPA strongly encourages more frequent auditing. The
audit should (preferably) be conducted by a trained experienced
technician other than the routine site operator. The audit is made
by measuring the analyzer's normal operating flow rate using a flow
rate transfer standard certified in accordance with section 2.6 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 flow rate of the transfer
standard and the corresponding flow rate measured (indicated) by the
analyzer. The percent differences between these flow rates are used
to validate the one-point flow rate verification checks used to
estimate bias as described in section 4.2.3 of this appendix.
3.2.5 Collocated Sampling Procedures for PM2.5. For
each pair of collocated monitors, designate one sampler as the
primary monitor whose concentrations will be used to report air
quality for the site, and designate the other as the audit monitor.
3.2.5.1 Each EPA designated Federal reference method (FRM) or
Federal equivalent method (FEM) within a primary quality assurance
organization must:
(a) Have 15 percent of the monitors collocated (values of 0.5
and greater round up); and
(b) Have at least 1 collocated monitor (if the total number of
monitors is less than 3). The first collocated monitor must be a
designated FRM monitor.
3.2.5.2 In addition, monitors selected for collocation must also
meet the following requirements:
(a) A primary monitor designated as an EPA FRM shall be
collocated with an audit monitor having the same EPA FRM method
designation.
(b) For each primary monitor model designated as an EPA FEM used
by the PQAO, 50 percent of the monitors designated for collocation
shall be collocated with an audit monitor having the same method
designation and 50 percent of the monitors shall be collocated with
an FRM audit monitor. If the primary quality assurance
[[Page 61307]]
organization only has one FEM monitor it shall be collocated with an
FRM audit monitor. If there are an odd number of collocated monitors
required, the additional monitor shall be an FRM audit monitor. An
example of this procedure is found in Table A-3 of this appendix.
3.2.5.3 The collocated monitors should be deployed according to
the following protocol:
(a) 80 percent of the collocated audit monitors should be
deployed at sites with annual average or daily concentrations
estimated to be within 20 percent of the applicable
NAAQS and the remainder at what the monitoring organizations
designate as high value sites;
(b) If an organization has no sites with annual average or daily
concentrations within 20 percent of the annual NAAQS
(or 24-hour NAAQS if that is affecting the area), 60 percent of the
collocated audit monitors should be deployed at those sites with the
annual mean concentrations (or 24-hour NAAQS if that is affecting
the area) among the highest 25 percent for all sites in the network.
3.2.5.4 In determining the number of collocated sites required
for PM2.5, monitoring networks for visibility assessments
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 FRM, FEM or ARM is not required to be included in the
number of sites which are used to determine the number of collocated
monitors.
3.2.5.5 For each PSD monitoring network, one site must be
collocated. A site with the predicted highest 24-hour pollutant
concentration must be selected.
3.2.5.6 The two collocated monitors must be within 4 meters of
each other and at least 2 meters apart for flow rates greater than
200 liters/min or at least 1 meter apart for samplers having flow
rates less than 200 liters/min 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.
3.2.5.7 Sample the collocated audit monitor for SLAMS sites on a
12-day schedule; sample PSD sites on a 6-day schedule or every third
day for PSD daily monitors. If a primary quality assurance
organization has only one collocated monitor, higher sampling
frequencies than the 12-day schedule may be needed in order to
produce about 25 valid sample pairs a year. Report the measurements
from both primary and collocated audit monitors at each collocated
sampling site. The calculations for evaluating precision between the
two collocated monitors are described in section 4.3.1 of this
appendix.
3.2.6 Collocated Sampling Procedures for PM10-2.5.
For the PM10-2.5 network, all automated methods must be
designated as Federal equivalent methods (FEMs). For each pair of
collocated monitors, designate one sampler as the primary monitor
whose concentrations will be used to report air quality for the
site, and designate the other as the audit monitor.
3.2.6.1 The EPA shall ensure that each EPA designated FEM within
the national PM10-2.5 monitoring network must:
(a) Have 15 percent of the monitors collocated (values of 0.5
and greater round up); and
(b) Have at least 2 collocated monitors (if the total number of
monitors is less than 10). The first collocated monitor must be a
designated FRM monitor and the second must be a monitor of the same
method designation. Both collocated FRM and FEM monitors can be
located at the same site.
3.2.6.2 The Regional Administrator for the EPA Regions where the
FEMs are implemented will select the sites for collocated
monitoring. The site selection process shall consider giving
priority to sites at primary quality assurance organizations or
States with more than one PM10-2.5 site, sites considered
important from a regional perspective, and sites needed for an
appropriate distribution among rural and urban NCore sites.
Depending on the speed at which the PM10-2.5 network is
deployed, the first sites implementing FEMs shall be required to
perform collocation until there is a larger distribution of FEM
monitors implemented in the network.
3.2.6.3 The two collocated monitors must be within 4 meters of
each other and at least 2 meters apart for flow rates greater than
200 liters/min or at least 1 meter apart for samplers having flow
rates less than 200 liters/min 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.
3.2.6.4 Sample the collocated audit monitor for SLAMS sites on a
12-day schedule. Report the measurements from both primary and
collocated audit monitors at each collocated sampling site. The
calculations for evaluating precision between the two collocated
monitors are described in section 4.3.1 of this appendix.
3.2.7 PM2.5 Performance Evaluation Program (PEP)
Procedures. The PEP is an independent assessment used to estimate
total measurement system bias. These evaluations will be performed
under the PM Performance Evaluation Program (PEP) (section 2.4 of
this appendix) or a comparable program. Performance evaluations will
be performed on the SLAMS monitors annually within each primary
quality assurance organization. For primary quality assurance
organizations with less than or equal to five monitoring sites, five
valid performance evaluation audits must be collected and reported
each year. For primary quality assurance organizations with greater
than five monitoring sites, eight valid performance evaluation
audits must be collected and reported each year. A valid performance
evaluation audit means that both the primary monitor and PEP audit
concentrations are valid and above 3 [mu]g/m3.
Additionally, each year, every designated FRM or FEM within a
primary quality assurance organization must:
(1) Have each method designation evaluated each year; and,
(2) Have all FRM or FEM samplers subject to a PEP audit at least
once every six years; which equates to approximately 15 percent of
the monitoring sites audited each year.
(b) Additional information concerning the Performance Evaluation
Program is contained in reference 10 of this appendix. The
calculations for evaluating bias between the primary monitor and the
performance evaluation monitor for PM2.5 are described in
section 4.3.2 of this appendix.
3.2.8 PM10-2.5 Performance Evaluation Program. For
the PM10-2.5 network, all automated methods will be
designated as federal equivalent methods (FEMs). One performance
evaluation audit, as described in section 3.2.7 must be performed at
one PM10-2.5 site in each primary quality assurance
organization each year. The calculations for evaluating bias between
the primary monitor(s) and the performance evaluation monitors for
PM10-2.5 are described in section 4.1.3 of this appendix.
3.3 Measurement Quality Checks of Manual Methods. Table A-2 of
this appendix provides a summary of the types and frequency of the
measurement quality checks that will be described in this section.
3.3.1 Collocated Sampling Procedures for PM10. For
each network of manual PM10 methods, select 15 percent
(or at least one) of the monitoring sites within the primary quality
assurance organization for collocated sampling. For purposes of
precision assessment, networks for measuring total suspended
particulate (TSP) and PM10 shall be considered separately
from one another. However, PM10 samplers used in the
PM10-2.5 network, may be counted along with the
PM10 samplers in the PM10 network as long as
the PM10 samplers in both networks are the same method
designation. 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 EPA Regional Administrator may be selected.
3.3.1.1 In determining the number of collocated sites required
for PM10, monitoring networks for lead (Pb) should be
treated independently from networks for particulate matter (PM),
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 Pb site and a collocated PM site may serve as a
collocated site for both networks.
3.3.1.2 The two collocated monitors must be within 4 meters of
each other and at least 2 meters apart for flow rates greater than
200 liters/min or at least 1 meter apart for samplers having flow
rates less than 200 liters/min to preclude airflow interference.
Calibration, sampling, analysis and verification/validation
procedures must be the same for both collocated samplers and the
same as for all other samplers in the network.
3.3.1.3 For each pair of collocated samplers, designate one
sampler as the
[[Page 61308]]
primary sampler whose samples will be used to report air quality for
the site, and designate the other as the audit sampler. Sample SLAMS
sites on a 12-day schedule; sample PSD sites on a 6-day schedule or
every third day for PSD daily samplers. If a primary quality
assurance organization has only one collocated monitor, higher
sampling frequencies than the 12-day schedule may be needed in order
to produce approximately 25 valid sample pairs a year. 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 4.2.1 of this appendix.
3.3.2 Flow Rate Verification for Particulate Matter. Follow the
same procedure as described in section 3.2.3 of this appendix for
PM2.5, PM10 (low-volume instruments), and
PM10-2.5. High-volume PM10 and TSP instruments
can also follow the procedure in section 3.2.3 but the audits are
required to be conducted quarterly. The percent differences between
the audit and measured flow rates are used to assess the bias of the
monitoring data as described in section 4.2.2 of this appendix.
3.3.3 Semi-Annual Flow Rate Audit for Particulate Matter. Follow
the same procedure as described in section 3.2.4 of this appendix
for PM2.5, PM10, PM10-2.5 and TSP
instruments. The percent differences between these flow rates are
used to validate the one-point flow rate verification checks used to
estimate bias as described in section 4.2.3 of this appendix. 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.
3.3.4 Pb Methods.
3.3.4.1 Annual Flow Rate. For the Pb Reference Method (40 CFR
part 50, appendix G), the flow rates of the high-volume Pb samplers
shall be verified and audited using the same procedures described in
sections 3.3.2 and 3.3.3 of this appendix.
3.3.4.2 Pb Strips. Each calendar quarter or sampling quarter
(PSD), audit the Pb Reference Method analytical procedure using
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 centimeters
(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 ambient
Range Pb concentration, Pb concentration,
[mu]g/strip [mu]g/m3 1
------------------------------------------------------------------------
1............................... 100-300 0.5-1.5
2............................... 400-1,000 3.0-5.0
------------------------------------------------------------------------
\1\ Equivalent ambient Pb concentration in [mu]/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.
(a) Audit samples must be extracted using the same extraction
procedure used for exposed filters.
(b) 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.
(c) Report the audit concentrations (in [mu]g Pb/strip) and the
corresponding measured concentrations (in [mu]g Pb/strip) using AQS
unit code 077. The relative percent differences between the
concentrations are used to calculate analytical accuracy as
described in section 4.4.2 of this appendix.
(d) The audits of an equivalent Pb method are conducted and
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.
3.3.5 Collocated Sampling Procedures for PM2.5.
Follow the same procedure as described in section 3.2.5 of this
appendix. PM2.5 samplers used in the PM10-2.5
network, may be counted along with the PM2.5 samplers in
the PM2.5 network as long as the PM2.5
samplers in both networks are the same method designation.
3.3.6 Collocated Sampling Procedures for PM10-2.5.
All designated FRMs within the PM10-2.5 monitoring
network must have 15 percent of the monitors collocated (values of
0.5 and greater round up) at the PM10-2.5 sites. All FRM
method designations can be aggregated.
3.3.6.1 The EPA shall ensure that each designated FEM within the
PM10-2.5 monitoring network must:
(a) Have 15 percent of the monitors collocated (values of 0.5
and greater round up); and
(b) Have at least 2 collocated monitors (if the total number of
monitors is less than 10). The first collocated monitor must be a
designated FRM monitor and the second must be a monitor of the same
method designation. Both collocated FRM and FEM monitors can be
located at the same site.
3.3.6.2 The Regional Administrator for the EPA Region where the
FRM or FEMs are implemented will select the sites for collocated
monitoring. The collocation site selection process shall consider
sites at primary quality assurance organizations or States with more
than one PM10-2.5 site; primary quality assurance
organizations already monitoring for PM10 and
PM2.5 using FRMs or FEMs; and an appropriate distribution
among rural and urban NCore sites. Monitoring organizations
implementing PM10 samplers and PM2.5 FRM
samplers of the same method designation as the PM10-2.5
FRM can include the PM10-2.5 monitors in their respective
PM10 and PM2.5 count. Follow the same
procedures as described in sections 3.2.6.2 and 3.2.6.3 of this
appendix.
3.3.7 PM2.5 Performance Evaluation Program (PEP)
Procedures. Follow the same procedure as described in section 3.2.7
of this appendix.
3.3.8 PM10-2.5 Performance Evaluation Program (PEP)
Procedures. One performance evaluation audit, as described in
section 3.2.7 of this appendix must be performed at one
PM10-2.5 site in each primary quality assurance
organization each year. Monitoring organizations implementing
PM2.5 FRM samplers of the same method designation in both
the PM2.5 and the PM10-2.5 networks can
include the PM10-2.5 performance evaluation audit in
their respective PM2.5 performance evaluation count as
long as the performance evaluation is conducted at the
PM10-2.5 site. The calculations for evaluating bias
between the primary monitor(s) and the performance evaluation
monitors for PM10-2.5 are described in section 4.1.3 of
this appendix.
4. Calculations for Data Quality Assessment
(a) Calculations of measurement uncertainty are carried out by
EPA according to the following procedures. Primary quality assurance
organizations should report the data for all appropriate measurement
quality checks as specified in this appendix even though they may
elect to perform some or all of the calculations in this section on
their own.
(b) The EPA will provide annual assessments of data quality
aggregated by site and primary quality assurance organization for
SO2, NO2, O3 and CO and by primary
quality assurance organization for PM10,
PM2.5, PM10-2.5 and Pb.
(c) At low concentrations, agreement between the measurements of
collocated samplers, expressed as relative percent difference or
percent difference, may be relatively poor. For this reason,
collocated measurement pairs are selected for use in the precision
and bias calculations only when both measurements are equal to or
above the following limits:
(1) TSP: 20 [mu]g/m3.
(2) Pb: 0.15 [mu]g/m3.
(3) PM10 (Hi-Vol): 15 [mu]g/m3.
(4) PM10 (Lo-Vol): 3 [mu]g/m3.
(5) PM10-2.5 and PM2.5: 3 [mu]g/m3.
4.1 Statistics for the Assessment of QC Checks for
SO2, NO2, O3 and CO.
4.1.1 Percent Difference. All measurement quality checks start
with a comparison of an audit concentration or value (flowrate) to
the concentration/value measured by the analyzer and use percent
difference as the comparison statistic as described in equation 1 of
this section. For
[[Page 61309]]
each single point check, calculate the percent difference, di, as
follows:
[GRAPHIC] [TIFF OMITTED] TR17OC06.041
where, meas is the concentration indicated by the monitoring
organization's instrument and audit is the audit concentration of
the standard used in the QC check being measured.
4.1.2 Precision Estimate. The precision estimate is used to
assess the one-point QC checks for SO2, NO2,
O3, or CO described in section 3.2.1 of this appendix.
The precision estimator is the coefficient of variation upper bound
and is calculated using equation 2 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.042
where, X20.1,n-1 is the 10th percentile of a
chi-squared distribution with n-1 degrees of freedom.
4.1.3 Bias Estimate. The bias estimate is calculated using the
one-point QC checks for SO2, NO2,
O3, or CO described in section 3.2.1 of this appendix and
the performance evaluation program for PM10-2.5 described
in sections 3.2.8 and 3.3.8 of this appendix. The bias estimator is
an upper bound on the mean absolute value of the percent differences
as described in equation 3 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.043
where, n is the number of single point checks being aggregated;
t0.95,n-1 is the 95th quantile of a t-distribution with
n-1 degrees of freedom; the quantity AB is the mean of the absolute
values of the di's and is calculated using equation 4 of this
section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.044
and the quantity AS is the standard deviation of the absolute value
of the di's and is calculated using equation 5 of this section:
[GRAPHIC] [TIFF OMITTED] TR17OC06.045
4.1.3.1 Assigning a sign (positive/negative) to the bias
estimate. Since the bias statistic as calculated in equation 3 of
this appendix uses absolute values, it does not have a tendency
(negative or positive bias) associated with it. A sign will be
designated by rank ordering the percent differences of the QC check
samples from a given site for a particular assessment interval.
4.1.3.2 Calculate the 25th and 75th percentiles of the percent
differences for each site. The absolute bias upper bound should be
flagged as positive if both percentiles are positive and negative if
both percentiles are negative. The absolute bias upper bound would
not be flagged if the 25th and 75th percentiles are of different
signs.
4.1.4 Validation of Bias Using the one-point QC Checks. The
annual performance evaluations for SO2, NO2,
O3, or CO described in section 3.2.2 of this appendix are
used to verify the results obtained from the one-point QC checks and
to validate those results across a range of concentration levels. To
quantify this annually at the site level and at the 3-year primary
quality assurance organization level, probability limits will be
calculated from the one-point QC checks using equations 6 and 7 of
this appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.064
[GRAPHIC] [TIFF OMITTED] TR17OC06.065
where, m is the mean (equation 8 of this appendix):
[GRAPHIC] [TIFF OMITTED] TR17OC06.046
where, k is the total number of one point QC checks for the interval
being evaluated and S is the standard deviation of the percent
differences (equation 9 of this appendix) as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC06.047
4.1.5 Percent Difference. Percent differences for the
performance evaluations, calculated using equation 1 of this
appendix can be compared to the probability intervals for the
respective site or at the primary quality assurance organization
level. Ninety-five percent of the individual percent differences
(all audit concentration levels) for the performance evaluations
should be captured within the probability intervals for the primary
quality assurance organization.
4.2 Statistics for the Assessment of PM10.
4.2.1 Precision Estimate from Collocated Samplers. Precision is
estimated via duplicate measurements from collocated samplers of the
same type. It is recommended that the precision be aggregated at the
primary quality assurance organization level quarterly, annually,
and at the 3-year level. The data pair would only be considered
valid if both concentrations are greater than the minimum values
specified in section 4(c) of this appendix. For each collocated data
pair, calculate the relative percent difference, di, using equation
10 of this appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.048
where, Xi is the concentration from the primary sampler and Yi is
the concentration value from the audit sampler. The coefficient of
variation upper bound is calculated using the equation 11 of this
appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.049
where, n is the number of valid data pairs being aggregated, and X
\2\0.1.n-1 is the 10th percentile of a chi-squared
distribution with n1 degrees of freedom. The factor of 2 in the
denominator adjusts for the fact that each di is calculated from two
values with error.
4.2.2 Bias Estimate Using One-Point Flow Rate Verifications. For
each one-point flow rate verification described in sections 3.2.3
and 3.3.2 of this appendix, calculate the percent difference in
volume using equation 1 of this appendix where meas is the value
indicated by the sampler's volume measurement and audit is the
actual volume indicated by the auditing flow meter. The absolute
volume bias upper bound is then calculated using equation 3, where n
is the number of flow rate audits being aggregated;
t0.95,n-1 is the 95th quantile of a t-distribution with
n-1 degrees of freedom, the quantity AB is the mean of the absolute
values of the di's and is calculated using equation 4 of this
appendix , and the quantity AS in equation 3 of this appendix is the
standard deviation of the absolute values if the di's and is
calculated using equation 5 of this
4.2.3 Assessment Semi-Annual Flow Rate Audits. The flow rate
audits described in sections 3.2.4 and 3.3.3 of this appendix are
used to assess the results obtained from the one-point flow rate
verifications and to provide an estimate of flow rate acceptability.
For each flow rate audit, calculate the percent difference in volume
using equation 1 of this appendix where meas is the value indicated
by the sampler's volume measurement and audit is the actual volume
indicated by the auditing flow meter. To quantify this annually and
at the 3-year primary quality assurance organization level,
probability limits are calculated from the percent differences using
equations 6 and 7 of this appendix where m is the mean described in
equation 8 of this appendix and k is the total number of one-point
flow rate verifications for the year and S is the standard deviation
of the percent differences as described in equation 9 of this
appendix.
[[Page 61310]]
4.2.4 Percent Difference. Percent differences for the annual
flow rate audit concentration, calculated using equation 1 of this
appendix, can be compared to the probability intervals for the one-
point flow rate verifications for the respective primary quality
assurance organization. Ninety-five percent of the individual
percent differences (all audit concentration levels) for the
performance evaluations should be captured within the probability
intervals for primary quality assurance organization.
4.3 Statistics for the Assessment of PM2.5 and
PM10-2.5.
4.3.1 Precision Estimate. Precision for collocated instruments
for PM2.5 and PM10-2.5 may be estimated where
both the primary and collocated instruments are the same method
designation and when the method designations are not similar. Follow
the procedure described in section 4.2.1 of this appendix. In
addition, one may want to perform an estimate of bias when the
primary monitor is an FEM and the collocated monitor is an FRM.
Follow the procedure described in section 4.1.3 of this appendix in
order to provide an estimate of bias using the collocated data.
4.3.2 Bias Estimate. Follow the procedure described in section
4.1.3 of this appendix for the bias estimate of PM10-2.5.
The PM2.5 bias estimate is calculated using the paired
routine and the PEP monitor data described in section 3.2.6 of this
appendix. Calculate the percent difference, di, using equation 1 of
this appendix, where meas is the measured concentration from
agency's primary monitor and audit is the concentration from the PEP
monitor. The data pair would only be considered valid if both
concentrations are greater than the minimum values specified in
section 4(c) of this appendix. Estimates of bias are presented for
various levels of aggregation, sometimes aggregating over time,
sometimes aggregating over samplers, and sometimes aggregating over
both time and samplers. These various levels of aggregation are
achieved using the same basic statistic.
4.3.2.1 This statistic averages the individual biases described
in equation 1 of this appendix to the desired level of aggregation
using equation 12 of this appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.050
where, nj is the number of pairs and d1,
d2, dnj are the biases for each of the pairs
to be averaged.
4.3.2.2 Confidence intervals can be constructed for these
average bias estimates in equation 12 of this appendix using
equations 13 and 14 of this appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.051
[GRAPHIC] [TIFF OMITTED] TR17OC06.052
Where, t0.95,df is the 95th quantile of a t-
distribution with degrees of freedom df = nj - 1 and s is
an estimate of the variability of the average bias calculated using
equation 15 of this appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.053
4.4 Statistics for the Assessment of Pb.
4.4.1 Precision Estimate. Follow the same procedures as
described for PM10 in section 4.2.1 of this appendix
using the data from the collocated instruments. The data pair would
only be considered valid if both concentrations are greater than the
minimum values specified in section 4(c) of this appendix.
4.4.2 Bias Estimate. In order to estimate bias, the information
from the flow rate audits and the Pb strip audits needs to be
combined as described below. To be consistent with the formulas for
the gases, the recommended procedures are to work with relative
errors of the lead measurements. The relative error in the
concentration is related to the relative error in the volume and the
relative error in the mass measurements using equation 16 of this
appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.054
As with the gases, an upper bound for the absolute bias is
desired. Using equation 16 above, the absolute value of the relative
(concentration) error is bounded by equation 17 of this appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.055
[[Page 61311]]
The quality indicator data collected are then used to bound each
part of equation 17 separately.
4.4.2.1 Flow rate calculations. For each flow rate audit,
calculate the percent difference in volume by equation 1 of this
appendix where meas is the value indicated by the sampler's volume
measurement and audit is the actual volume indicated by the auditing
flow meter. The absolute volume bias upper bound is then calculated
using equation 3 of this appendix where n is the number of flow rate
audits being aggregated; t0.95,n-1 is the 95th quantile
of a t-distribution with n-1 degrees of freedom; the quantity AB is
the mean of the absolute values of the di's and is calculated using
equation 4, and the quantity AS in equation 3 of this appendix is
the standard deviation of the absolute values of the di's and is
calculated using equation 5 of this appendix.
4.4.2.2 Lead strip calculations. Similarly for each lead strip
audit, calculate the percent difference in mass by equation 1 where
meas is the value indicated by the mass measurement and audit is the
actual lead mass on the audit strip. The absolute mass bias upper
bound is then calculated using equation 3 of this appendix where n
is the number of lead strip audits being aggregated;
t0.95,n-1 is the 95th quantile of a t-distribution with
n-1 degrees of freedom; the quantity AB is the mean of the absolute
values of the di's and is calculated using equation 4 of this
appendix and the quantity AS in equation 3 of this appendix is the
standard deviation of the absolute values of the di's and is
calculated using equation 5 of this appendix.
4.4.2.3 Final bias calculation. Finally, the absolute bias upper
bound is given by combining the absolute bias estimates of the flow
rate and Pb strips using equation 18 of this appendix:
[GRAPHIC] [TIFF OMITTED] TR17OC06.056
where, the numerator and denominator have been multiplied by 100
since everything is expressed as a percentage.
4.5 Time Period for Audits. The statistics in this section
assume that the mass and flow rate audits represent the same time
period. Since the two types of audits are not performed at the same
time, the audits need to be grouped by common time periods.
Consequently, the absolute bias estimates should be done on annual
and 3-year levels. The flow rate audits are site-specific, so the
absolute bias upper bound estimate can be done and treated as a
site-level statistic.
5. Reporting Requirements
5.1 SLAMS Reporting Requirements. For each pollutant, prepare a
list of all monitoring sites and their AQS site identification codes
in each primary quality assurance organization and submit the list
to the appropriate EPA Regional Office, with a copy to AQS. Whenever
there is a change in this list of monitoring sites in a primary
quality assurance organization, report this change to the EPA
Regional Office and to AQS.
5.1.1 Quarterly Reports. For each quarter, each primary quality
assurance organization shall report to AQS directly (or via the
appropriate EPA Regional Office for organizations not direct users
of AQS) the results of all valid measurement quality checks it has
carried out during the quarter. The quarterly reports must be
submitted consistent with the data reporting requirements specified
for air quality data as set forth in Sec. 58.16. The EPA strongly
encourages early submission of the quality assurance data in order
to assist the monitoring organizations control and evaluate the
quality of the ambient air data.
5.1.2 Annual Reports.
5.1.2.1 When the monitoring organization has certified relevant
data for the calendar year, EPA will calculate and report the
measurement uncertainty for the entire calendar year.
5.2 PSD Reporting Requirements. At the end of each sampling
quarter, the organization must report the appropriate statistical
assessments in section 4 of this appendix for the pollutants
measured. All data used to calculate reported estimates of precision
and bias including span checks, collocated sampler and audit results
must be made available to the permit granting authority upon
request.
6.0 References
(1) American National Standard--Specifications and Guidelines
for Quality Systems for Environmental Data Collection and
Environmental Technology Programs. ANSI/ASQC E4-2004. February 2004.
Available from American Society for Quality Control, 611 East
Wisconsin Avenue, Milwaukee, WI 53202.
(2) EPA Requirements for Quality Management Plans. EPA QA/R-2.
EPA/240/B-01/002. March 2001. Office of Environmental Information,
Washington DC 20460. http://www.epa.gov/quality/qs-docs/r2-final.pdf.
(3) EPA Requirements for Quality Assurance Project Plans for
Environmental Data Operations. EPA QA/R-5. EPA/240/B-01/003. March
2001. Office of Environmental Information, Washington DC 20460.
http://www.epa.gov/quality/qs-docs/r5-final.pdf.
(4) EPA Traceability Protocol for Assay and Certification of
Gaseous Calibration Standards. EPA-600/R-97/121. September 1997.
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. EPA/240/B-06/001. February, 2006. Office of Environmental
Information, Washington DC 20460. http://www.epa.gov/quality/qs-docs/g4-final.pdf.
(6) List of Designated Reference and Equivalent Methods.
Available from U.S. Environmental Protection Agency, National
Exposure Research Laboratory, Human Exposure and Atmospheric
Sciences Division, MD-D205-03, Research Triangle Park, NC 27711.
http://www.epa.gov/ttn/amtic/criteria.html.
(7) 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. http://www.epa.gov/ttn/amtic/cpreldoc.html.
(8) 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. http://www.epa.gov/ttn/amtic/cpreldoc.html.
(9) 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. http://www.epa.gov/ ttn/amtic/qabook.html.
(10) Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume II: Part 1--Ambient Air Quality Monitoring Program
Quality System Development. EPA-454/R-98-004. http://www.epa.gov/ttn/amtic/qabook.html.
[[Page 61312]]
Table A-1 of Appendix A to Part 58. Difference and Similarities Between
SLAMS and PSD Requirements
------------------------------------------------------------------------
Topic SLAMS PSD
------------------------------------------------------------------------
Requirements.................... 1. The
development,
documentation,
and
implementation of
an approved
quality system.
2. The assessment
of data quality.
3. The use of
reference,
equivalent, or
approved methods.
4. The use of
calibration
standards
traceable to NIST
or other primary
standard.
5. The
participation in
EPA performance
evaluations and
the permission
for EPA to
conduct system
audits.
Monitoring and QA Responsibility State/local agency Source owner/
via the ``primary operator.
quality assurance
organization''.
Monitoring Duration............. Indefinitely...... Usually up to 12
months.
Annual Performance Evaluation Standards and Personnel,
(PE). equipment standards and
different from equipment
those used for different from
spanning, those used for
calibration, and spanning,
verifications. calibration, and
Prefer different verifications.
personnel.
PE audit rate:
--Automated................. 100% per year..... 100% per quarter.
--Manual.................... Varies depending 100% per quarter.
on pollutant. See
Table A-2 of this
appendix.
Precision Assessment:
--Automated................. One-point QC check One point QC check
biweekly but data biweekly.
quality dependent.
--Manual.................... Varies depending One site: 1 every
on pollutant. See 6 days or every
Table A-2 of this third day for
appendix. daily monitoring
(TSP and Pb).
Reporting
--Automated................. By site--EPA By site--source
performs owner/operator
calculations performs
annually. calculations each
sampling quarter.
--Manual.................... By reporting By site--source
organization--EPA owner/operator
performs performs
calculations calculations each
annually. sampling quarter.
------------------------------------------------------------------------
Table A-2 of Appendix A to Part 58. Minimum Data Assessment Requirements for SLAMS Sites
----------------------------------------------------------------------------------------------------------------
Parameters
Method Assessment method Coverage Minimum frequency reported
----------------------------------------------------------------------------------------------------------------
Automated Methods
----------------------------------------------------------------------------------------------------------------
1-Point QC for SO2, NO2, O3, CO. Response check at Each analyzer..... Once per 2 weeks.. Audit
concentration concentration \1\
0.01-0.1 ppm SO2, and measured
NO2, O3, and 1-10 concentration
ppm CO. \2\.
Annual performance evaluation See section 3.2.2 Each analyzer..... Once per year..... Audit
for SO2, NO2, O3, CO. of this appendix. concentration \1\
and measured
concentration \2\
for each level.
Flow rate verification PM10, Check of sampler Each sampler...... Once every month.. Audit flow rate
PM2.5, PM10 2.5. flow rate. and measured flow
rate indicated by
the sampler.
Semi-annual flow rate audit Check of sampler Each sampler...... Once every 6...... Audit flow rate
PM10, PM2.5, PM10 2.5. flow rate using and measured flow
independent rate indicated by
standard. the sampler.
Collocated sampling PM2.5, Collocated 15%............... Every 12 days..... Primary sampler
PM10 2.5. samplers. concentration and
duplicate sampler
concentration.
Performance evaluation program Collocated 1. 5 valid audits Over all 4 Primary sampler
PM2.5, PM10 2.5. samplers. for primary QA quarters. concentration and
orgs, with <= 5 performance
sites. evaluation
2. 8 valid audits sampler
for primary QA concentration.
orgs, with > 5
sites.
3. All samplers in
6 years.
----------------------------------------------------------------------------------------------------------------
Manual Methods
----------------------------------------------------------------------------------------------------------------
Collocated sampling PM10, TSP, Collocated 15%............... Every 12 days PSD-- Primary sampler
PM10 2.5, PM2.5. samplers. every 6 days. concentration and
duplicate sampler
concentration.
Flow rate verification PM10 (low Check of sampler Each sampler...... Once every month.. Audit flow rate
Vol), PM10 2.5, PM2.5. flow rate. and measured flow
rate indicated by
the sampler.
[[Page 61313]]
Flow rate verification PM10 Check of sampler Each sampler...... Once every quarter Audit flow rate
(High-Vol), TSP. flow rate. and measured flow
rate indicated by
the sampler.
Semi-annual flow rate audit Check of sampler Each sampler, all Once every 6 Audit flow rate
PM10, TSP, PM10 2.5, PM2.5. flow rate using locations. months. and measured flow
independent rate indicated by
standard. the sampler.
Manual Methods Lead............. 1. Check of sample 1. Each sampler... 1. Include with 1. Same as for
flow rate as for 2. Analytical..... TSP. TSP.
TSP. 2. Each quarter... 2. Actual
2. Check of concentration.
analytical system
with Pb audit
strips.
Performance evaluation program Collocated 1. 5 valid audits Over all 4 Primary sampler
PM2.5, PM10 2.5. samplers. for primary QA quarters. concentration and
orgs, with <= 5 performance
sites. evaluation
2. 8 valid audits sampler
for primary QA concentration.
orgs, with >= 5
sites.
3. All samplers in
6 years.
----------------------------------------------------------------------------------------------------------------
\1\ Effective concentration for open path analyzers.
\2\ Corrected concentration, if applicable, for open path analyzers.
Table A-3 of Appendix A to Part 58.--Summary of PM2.5 Number and Type of Collocation (15% Collocation
Requirement) Needed as an Example of a Primary Quality Assurance Organization That Has 54 Monitors and Procured
FRMs and Three Other Equivalent Method Types
----------------------------------------------------------------------------------------------------------------
No. of
collocated
Total no. of Total no. No. of monitors of
Primary sampler method designation monitors collocated collocated FRM same method
designation as
primary
----------------------------------------------------------------------------------------------------------------
FRM............................................. 20 3 3 n/a
FEM (A)......................................... 20 3 2 1
FEM (C)......................................... 2 1 1 0
FEM (D)......................................... 12 2 1 1
----------------------------------------------------------------------------------------------------------------
Appendix B--[Removed and Reserved]
34. Appendix B to part 58 is removed and reserved
35. Appendix C to part 58 is revised to read as follows:
Appendix C to Part 58--Ambient Air Quality Monitoring Methodology
1.0 Purpose
2.0 SLAMS Ambient Air Monitoring Stations
3.0 NCore Ambient Air Monitoring Stations
4.0 Photochemical Assessment Monitoring Stations (PAMS)
5.0 Particulate Matter Episode Monitoring
6.0 References
1.0 Purpose
This appendix specifies the criteria pollutant monitoring
methods (manual methods or automated analyzers) which must be used
in SLAMS and NCore stations that are a subset of SLAMS.
2.0 SLAMS Ambient Air Monitoring Network
2.1 Except as otherwise provided in this appendix, a criteria
pollutant monitoring method used for making NAAQS decisions at a
SLAMS site must be a reference or equivalent method as defined in
Sec. 50.1 of this chapter.
2.2 Reserved
2.3 Any manual method or analyzer purchased prior to
cancellation of its reference or equivalent method designation under
Sec. 53.11 or Sec. 53.16 of this chapter may be used at a SLAMS
site following cancellation for a reasonable period of time to be
determined by the Administrator.
2.4 Approval of Non-designated Continuous PM2.5
Methods as Approved Regional Methods (ARMs) Operated Within a
Network of Sites. A method for PM2.5 that has not been
designated as an FRM or FEM as defined in Sec. 50.1 of this chapter
may be approved as an ARM for purposes of section 2.1 of this
appendix at a particular site or network of sites under the
following stipulations.
2.4.1 The candidate ARM must be demonstrated to meet the
requirements for PM2.5 Class III equivalent methods as
defined in subpart C of part 53 of this chapter. Specifically the
requirements for precision, correlation, and additive and
multiplicative bias apply. For purposes of this section 2.4, the
following requirements shall apply:
2.4.1.1 The candidate ARM shall be tested at the site(s) in
which it is intended to be used. For a network of sites operated by
one reporting agency or primary quality assurance organization, the
testing shall occur at a subset of sites to include one site in each
MSA/CSA, up to the first 2 highest population MSA/CSA and at least
one rural area or Micropolitan Statistical Area site. If the
candidate ARM for a network is already approved for purposes of this
section in another agency's network, subsequent testing shall
minimally occur at one site in a MSA/CSA and one rural area or
Micropolitan Statistical Area. There shall be no requirement for
tests at any other sites.
2.4.1.2 For purposes of this section, a full year of testing may
begin and end in any season, so long as all seasons are covered.
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 test specification for PM2.5 Class III
equivalent method precision defined in subpart C of part 53 of this
chapter applies; however, there is no specific requirement that
collocated continuous monitors be operated for purposes of
generating a statistic for coefficient of variation (CV). To provide
an estimate of precision that meets the requirement identified in
subpart C of part 53 of this chapter, agencies may cite peer-
reviewed published data or data in AQS that can be presented
demonstrating the candidate ARM operated will produce data that
meets the specification for precision of Class III PM2.5
methods.
2.4.1.5 A minimum of 90 valid sample pairs per site for the year
with no less than 20 valid sample pairs per season must be generated
for use in demonstrating that additive bias, multiplicative bias and
correlation meet the comparability requirements specified in subpart
C of part 53 of this chapter. A valid sample pair may be generated
with as little as one valid FRM and one valid candidate ARM
measurement per day.
[[Page 61314]]
2.4.1.6 For purposes of determining bias, FRM data with
concentrations less than 3 micrograms per cubic meter ([mu]g/m\3\)
may be excluded. Exclusion of data does not result in failure of
sample completeness specified in this section.
2.4.1.7 Data transformations are allowed to be used to
demonstrate meeting the comparability requirements specified in
subpart C of part 53 of this chapter. Data transformation may be
linear or non-linear, but must be applied in the same way to all
sites used in the testing.
2.4.2 The monitoring agency wishing to use an ARM must develop
and implement appropriate quality assurance procedures for the
method. Additionally, the following procedures are required for the
method:
2.4.2.1 The ARM must be consistently operated throughout the
network. Exceptions to a consistent operation must be approved
according to section 2.8 of this appendix;
2.4.2.2 The ARM must be operated on an hourly sampling frequency
capable of providing data suitable for aggregation into daily 24-
hour average measurements;
2.4.2.3 The ARM must use an inlet and separation device, as
needed, that are already approved in either the reference method
identified in appendix L to part 50 of this chapter or under part 53
of this chapter as approved for use on a PM2.5 reference
or equivalent method. The only exceptions to this requirement are
those methods that by their inherent measurement principle may not
need an inlet or separation device that segregates the aerosol; and
2.4.2.4 The ARM must be capable of providing for flow audits,
unless by its inherent measurement principle, measured flow is not
required. These flow audits are to be performed on the frequency
identified in appendix A to this part.
2.4.2.5 If data transformations are used, they must be described
in the monitoring agencies Quality Assurance Project plan (or
addendum to QAPP). The QAPP shall describe how often (e.g.,
quarterly, yearly) and under what provisions the data transformation
will be updated. For example, not meeting the data quality
objectives for a site over a season or year may be cause for
recalculating a data transformation, but by itself would not be
cause for invalidating the data. Data transformations must be
applied prospectively, i.e., in real-time or near real-time, to the
data output from the PM2.5 continuous method. See
reference 7 of this appendix.
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 Assessments of data quality shall follow the same
frequencies and calculations as required under section 3 of appendix
A to this part with the following exceptions:
2.4.4.1 Collocation of ARM with FRM/FEM samplers must be
maintained at a minimum of 30 percent of the required SLAMS sites
with a minimum of 1 per network;
2.4.4.2 All collocated FRM/FEM samplers must maintain a sample
frequency of at least 1 in 6 sample days;
2.4.4.3 Collocated FRM/FEM samplers shall be located at the
design value site, with the required FRM/FEM samplers deployed among
the largest MSA/CSA in the network, until all required FRM/FEM are
deployed; and
2.4.4.4 Data from collocated FRM/FEM are to be substituted for
any calendar quarter that an ARM method has incomplete data.
2.4.4.5 Collocation with an ARM under this part for purposes of
determining the coefficient of variation of the method shall be
conducted at a minimum of 7.5 percent of the sites with a minimum of
1 per network. This is consistent with the requirements in appendix
A to this part for one-half of the required collocation of FRM/FEM
(15 percent) to be collocated with the same method.
2.4.4.6 Assessments of bias with an independent audit of the
total measurement system shall be conducted with the same frequency
as an FEM as identified in appendix A to this part.
2.4.5 Request for approval of a candidate ARM, that is not
already approved in another agency's network under this section,
must meet the general submittal requirements of section 2.7 of this
appendix. Requests for approval under this section when an ARM is
already approved in another agency's network are to be submitted to
the EPA Regional Administrator. Requests for approval under section
2.4 of this appendix must include the following requirements:
2.4.5.1 A clear and unique description of the site(s) at which
the candidate ARM 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.
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 AQS.
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 an ARM at a particular site or network of sites under
section 2.4 of this appendix, the Administrator will approve or
disapprove the method by letter to the person or agency requesting
such approval. When appropriate for methods that are already
approved in another SLAMS network, the EPA Regional Administrator
has approval/disapproval authority. In either instance, additional
information may be requested to assist with the decision.
2.5 [Reserved]
2.6 Use of Methods With Higher, Nonconforming Ranges in Certain
Geographical Areas.
2.6.1 [Reserved]
2.6.2 An analyzer may be used (indefinitely) on a range which
extends to concentrations higher than two times the upper limit
specified in table B-1 of part 53 of this chapter if:
2.6.2.1 The analyzer has more than one selectable range and has
been designated as a reference or equivalent method on at least one
of its ranges, or has been approved for use under section 2.5 (which
applies to analyzers purchased before February 18, 1975);
2.6.2.2 The pollutant intended to be measured with the analyzer
is likely to occur in concentrations more than two times the upper
range limit specified in table B-1 of part 53 of this chapter in the
geographical area in which use of the analyzer is proposed; and
2.6.2.3 The Administrator determines that the resolution of the
range or ranges for which approval is sought is adequate for its
intended use. For purposes of this section (2.6), ``resolution''
means the ability of the analyzer to detect small changes in
concentration.
2.6.3 Requests for approval under section 2.6.2 of this appendix
must meet the submittal requirements of section 2.7. Except as
provided in section 2.7.3 of this appendix, each request must
contain the information specified in section 2.7.2 in addition to
the following:
2.6.3.1 The range or ranges proposed to be used;
2.6.3.2 Test data, records, calculations, and test results as
specified in section 2.7.2.2 of this appendix for each range
proposed to be used;
2.6.3.3 An identification and description of the geographical
area in which use of the analyzer is proposed;
2.6.3.4 Data or other information demonstrating that the
pollutant intended to be measured with the analyzer is likely to
occur in concentrations more than two times the upper range limit
specified in table B-1 of part 53 of this chapter in the
geographical area in which use of the analyzer is proposed; and
2.6.3.5 Test data or other information demonstrating the
resolution of each proposed range that is broader than that
permitted by section 2.5 of this appendix.
2.6.4 Any person who has obtained approval of a request under
this section (2.6.2) shall assure that the analyzer for which
approval was obtained is used only in the geographical area
identified in the request and only while operated in the range or
ranges specified in the request.
2.7 Requests for Approval; Withdrawal of Approval.
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
Research Laboratory (MD-D205-03), U.S. Environmental Protection
Agency, Research Triangle Park, North Carolina 27711. For ARM that
are already approved in another agency's network, subsequent
[[Page 61315]]
requests for approval under section 2.4 are to be submitted to the
applicable EPA Regional Administrator.
2.7.2 Except as provided in section 2.7.3 of this appendix, each
request must contain:
2.7.2.1 A statement identifying the analyzer (e.g., by serial
number) and the method of which the analyzer is representative
(e.g., by manufacturer and model number); and
2.7.2.2 Test data, records, calculations, and test results for
the analyzer (or the method of which the analyzer is representative)
as specified in subpart B, subpart C, or both (as applicable) of
part 53 of this chapter.
2.7.3 A request may concern more than one analyzer or
geographical area and may incorporate by reference any data or other
information known to EPA from one or more of the following:
2.7.3.1 An application for a reference or equivalent method
determination submitted to EPA for the method of which the analyzer
is representative, or testing conducted by the applicant or by EPA
in connection with such an application;
2.7.3.2 Testing of the method of which the analyzer is
representative at the initiative of the Administrator under Sec.
53.7 of this chapter; or
2.7.3.3 A previous or concurrent request for approval submitted
to EPA under this section (2.7).
2.7.4 To the extent that such incorporation by reference
provides data or information required by this section (2.7) or by
sections 2.4, 2.5, or 2.6 of this appendix, independent data or
duplicative information need not be submitted.
2.7.5 After receiving a request under this section (2.7), the
Administrator may request such additional testing or information or
conduct such tests as may be necessary in his judgment for a
decision on the request.
2.7.6 If the Administrator determines, on the basis of any
available information, that any of the determinations or statements
on which approval of a request under this section was based are
invalid or no longer valid, or that the requirements of section 2.4,
2.5, or 2.6, as applicable, have not been met, he/she may withdraw
the approval after affording the person who obtained the approval an
opportunity to submit information and arguments opposing such
action.
2.8 Modifications of Methods by Users.
2.8.1 Except as otherwise provided in this section, no reference
method, equivalent method, or ARM may be used in a SLAMS network if
it has been modified in a manner that could significantly alter the
performance characteristics of the method without prior approval by
the Administrator. For purposes of this section, ``alternative
method'' means an analyzer, the use of which has been approved under
section 2.4, 2.5, or 2.6 of this appendix or some combination
thereof.
2.8.2 Requests for approval under this section (2.8) must meet
the submittal requirements of sections 2.7.1 and 2.7.2.1 of this
appendix.
2.8.3 Each request submitted under this section (2.8) must
include:
2.8.3.1 A description, in such detail as may be appropriate, of
the desired modification;
2.8.3.2 A brief statement of the purpose(s) of the modification,
including any reasons for considering it necessary or advantageous;
2.8.3.3 A brief statement of belief concerning the extent to
which the modification will or may affect the performance
characteristics of the method; and
2.8.3.4 Such further information as may be necessary to explain
and support the statements required by sections 2.8.3.2 and 2.8.3.3.
2.8.4 The Administrator will approve or disapprove the
modification by letter to the person or agency requesting such
approval within 75 days after receiving a request for approval under
this section and any further information that the applicant may be
asked to provide.
2.8.5 A temporary modification that could alter the performance
characteristics of a reference, equivalent, or ARM may be made
without prior approval under this section if the method is not
functioning or is malfunctioning, provided that parts necessary for
repair in accordance with the applicable operation manual cannot be
obtained within 45 days. Unless such temporary modification is later
approved under section 2.8.4 of this appendix, the temporarily
modified method shall be repaired in accordance with the applicable
operation manual as quickly as practicable but in no event later
than 4 months after the temporary modification was made, unless an
extension of time is granted by the Administrator. Unless and until
the temporary modification is approved, air quality data obtained
with the method as temporarily modified must be clearly identified
as such when submitted in accordance with Sec. 58.16 and must be
accompanied by a report containing the information specified in
section 2.8.3 of this appendix. A request that the Administrator
approve a temporary modification may be submitted in accordance with
sections 2.8.1 through 2.8.4 of this appendix. In such cases the
request will be considered as if a request for prior approval had
been made.
2.9 Use of IMPROVE Samplers at a SLAMS Site. ``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. Descriptions of the IMPROVE samplers and the data they
collect are available in references 4, 5, and 6 of this appendix.
3.0 NCore Ambient Air Monitoring Stations
3.1 Methods employed in NCore multipollutant sites used to
measure SO2, CO, NO2, O3,
PM2.5, or PM10-2.5 must be reference or
equivalent methods as defined in Sec. 50.1 of this chapter, or an
ARM as defined in section 2.4 of this appendix, for any monitors
intended for comparison with applicable NAAQS.
3.2 If alternative SO2, CO, NO2,
O3, PM2.5, or PM10-2.5 monitoring
methodologies are proposed for monitors not intended for NAAQS
comparison, such techniques must be detailed in the network
description required by Sec. 58.10 and subsequently approved by the
Administrator. Examples of locations that are not intended to be
compared to the NAAQS may be rural background and transport sites or
areas where the concentration of the pollutant is so low that it
would be more useful to operate a higher sensitivity method that is
not an FRM or FEM.
4.0 Photochemical Assessment Monitoring Stations (PAMS)
4.1 Methods used for O3 monitoring at PAMS must be
automated reference or equivalent methods as defined in Sec. 50.1
of this chapter.
4.2 Methods used for NO, NO2 and NOX
monitoring at PAMS should be automated reference or equivalent
methods as defined for NO2 in Sec. 50.1 of this chapter.
If alternative NO, NO2 or NOX monitoring
methodologies are proposed, such techniques must be detailed in the
network description required by Sec. 58.10 and subsequently
approved by the Administrator.
4.3 Methods for meteorological measurements and speciated VOC
monitoring are included in the guidance provided in references 2 and
3 of this appendix. If alternative VOC monitoring methodology
(including the use of new or innovative technologies), which is not
included in the guidance, is proposed, it must be detailed in the
network description required by Sec. 58.10 and subsequently
approved by the Administrator.
5.0 Particulate Matter Episode Monitoring
5.1 For short-term measurements of PM10 during air
pollution episodes (see Sec. 51.152 of this chapter) the
measurement method must be:
5.1.1 Either the ``Staggered PM10'' method or the
``PM10 Sampling Over Short Sampling Times'' method, both
of which are based on the reference method for PM10 and
are described in reference 1: or
5.1.2 Any other method for measuring PM10:
5.1.2.1 Which has a measurement range or ranges appropriate to
accurately measure air pollution episode concentration of
PM10,
5.1.2.2 Which has a sample period appropriate for short-term
PM10 measurements, and
5.1.2.3 For which a quantitative relationship to a reference or
equivalent method for PM10 has been established at the
use site. Procedures for establishing a quantitative site-specific
relationship are contained in reference 1.
5.2 PM10 methods other than the reference method are
not covered under the quality assessment requirements of appendix to
this part. Therefore, States must develop and implement their own
quality assessment procedures for those methods allowed under this
section 4. These quality assessment procedures should be similar or
analogous to
[[Page 61316]]
those described in section 3 of appendix A to this part for the
PM10 reference method.
6.0 References
1. Pelton, D. J. Guideline for Particulate Episode Monitoring
Methods, GEOMET Technologies, Inc., Rockville, MD. Prepared for U.S.
Environmental Protection Agency, Research Triangle Park, NC. EPA
Contract No. 68-02-3584. EPA 450/4-83-005. February 1983.
2. 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.
3. Quality Assurance Handbook for Air Pollution Measurement
Systems: Volume IV. Meteorological Measurements. Atmospheric
Research and Exposure Assessment Laboratory, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711. EPA 600/4-90-
0003. August 1989.
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.
7. Data Quality Objectives (DQOs) for Relating Federal Reference
Method (FRM) and Continuous PM2.5 Measurements to Report
an Air Quality Index (AQI). Office of Air Quality Planning and
Standards, U.S. Environmental Protection Agency, Research Triangle
Park, NC 27711. EPA 454/B-02-2002. November 2002.
36. Appendix D to part 58 is revised to read as follows:
Appendix D to Part 58--Network Design Criteria for Ambient Air Quality
Monitoring
1. Monitoring Objectives and Spatial Scales
2. General Monitoring Requirements
3. Design Criteria for NCore Sites
4. Pollutant-Specific Design Criteria for SLAMS Sites
5. Design Criteria for Photochemical Assessment Monitoring Stations
(PAMS)
6. References
1. Monitoring Objectives and Spatial Scales
The purpose of this appendix is to describe monitoring
objectives and general criteria to be applied in establishing the
required SLAMS ambient air quality monitoring stations and for
choosing general locations for additional monitoring sites. This
appendix also describes specific requirements for the number and
location of FRM, FEM, and ARM sites for specific pollutants, NCore
multipollutant sites, PM10 mass sites, PM2.5
mass sites, chemically-speciated PM2.5 sites, and
O3 precursor measurements sites (PAMS). These criteria
will be used by EPA in evaluating the adequacy of the air pollutant
monitoring networks.
1.1 Monitoring Objectives. The ambient air monitoring networks
must be designed to meet three basic monitoring objectives. These
basic objectives are listed below. The appearance of any one
objective in the order of this list is not based upon a prioritized
scheme. Each objective is important and must be considered
individually.
(a) Provide air pollution data to the general public in a timely
manner. Data can be presented to the public in a number of
attractive ways including through air quality maps, newspapers,
Internet sites, and as part of weather forecasts and public
advisories.
(b) Support compliance with ambient air quality standards and
emissions strategy development. Data from FRM, FEM, and ARM monitors
for NAAQS pollutants will be used for comparing an area's air
pollution levels against the NAAQS. Data from monitors of various
types can be used in the development of attainment and maintenance
plans. SLAMS, and especially NCore station data, will be used to
evaluate the regional air quality models used in developing emission
strategies, and to track trends in air pollution abatement control
measures' impact on improving air quality. In monitoring locations
near major air pollution sources, source-oriented monitoring data
can provide insight into how well industrial sources are controlling
their pollutant emissions.
(c) Support for air pollution research studies. Air pollution
data from the NCore network can be used to supplement data collected
by researchers working on health effects assessments and atmospheric
processes, or for monitoring methods development work.
1.1.1 In order to support the air quality management work
indicated in the three basic air monitoring objectives, a network
must be designed with a variety of types of monitoring sites.
Monitoring sites must be capable of informing managers about many
things including the peak air pollution levels, typical levels in
populated areas, air pollution transported into and outside of a
city or region, and air pollution levels near specific sources. To
summarize some of these sites, here is a listing of six general site
types:
(a) Sites located to determine the highest concentrations
expected to occur in the area covered by the network.
(b) Sites located to measure typical concentrations in areas of
high population density.
(c) Sites located to determine the impact of significant sources
or source categories on air quality.
(d) Sites located to determine general background concentration
levels.
(e) Sites located to determine the extent of regional pollutant
transport among populated areas; and in support of secondary
standards.
(f) Sites located to measure air pollution impacts on
visibility, vegetation damage, or other welfare-based impacts.
1.1.2 This appendix contains criteria for the basic air
monitoring requirements. The total number of monitoring sites that
will serve the variety of data needs will be substantially higher
than these minimum requirements provide. The optimum size of a
particular network involves trade-offs among data needs and
available resources. This regulation intends to provide for national
air monitoring needs, and to lend support for the flexibility
necessary to meet data collection needs of area air quality
managers. The EPA, State, and local agencies will periodically
collaborate on network design issues through the network assessment
process outlined in Sec. 58.10.
1.1.3 This appendix focuses on the relationship between
monitoring objectives, site types, and the geographic location of
monitoring sites. Included are a rationale and set of general
criteria for identifying candidate site locations in terms of
physical characteristics which most closely match a specific
monitoring objective. The criteria for more specifically locating
the monitoring site, including spacing from roadways and vertical
and horizontal probe and path placement, are described in appendix E
to this part.
1.2 Spatial Scales. (a) To clarify the nature of the link
between general monitoring objectives, site types, and the physical
location of a particular monitor, the concept of spatial scale of
representativeness is defined. The goal in locating monitors is to
correctly match the spatial scale represented by the sample of
monitored air with the spatial scale most appropriate for the
monitoring site type, air pollutant to be measured, and the
monitoring objective.
(b) Thus, spatial scale of representativeness is described in
terms of the physical dimensions of the air parcel nearest to a
monitoring site throughout which actual pollutant concentrations are
reasonably similar. The scales of representativeness of most
interest for the monitoring site types described above are as
follows:
(1) Microscale--Defines the concentrations in air volumes
associated with area dimensions ranging from several meters up to
about 100 meters.
(2) Middle scale--Defines the concentration typical of areas up
to several city blocks in size with dimensions ranging from about
100 meters to 0.5 kilometer.
(3) Neighborhood scale--Defines concentrations within some
extended area of the city that has relatively uniform land use with
dimensions in the 0.5 to 4.0 kilometers range. The neighborhood and
urban scales listed below have the potential to overlap in
applications that concern secondarily formed or homogeneously
distributed air pollutants.
(4) Urban scale--Defines concentrations within an area of city-
like dimensions, on the order of 4 to 50 kilometers. Within a city,
the geographic placement of sources may result in there being no
single site that can be said to represent air quality on an urban
scale.
(5) Regional scale--Defines usually a rural area of reasonably
homogeneous geography without large sources, and extends from tens
to hundreds of kilometers.
[[Page 61317]]
(6) National and global scales--These measurement scales
represent concentrations characterizing the nation and the globe as
a whole.
(c) Proper siting of a monitor requires specification of the
monitoring objective, the types of sites necessary to meet the
objective, and then the desired spatial scale of representativeness.
For example, consider the case where the objective is to determine
NAAQS compliance by understanding the maximum ozone concentrations
for an area. Such areas would most likely be located downwind of a
metropolitan area, quite likely in a suburban residential area where
children and other susceptible individuals are likely to be
outdoors. Sites located in these areas are most likely to represent
an urban scale of measurement. In this example, physical location
was determined by considering ozone precursor emission patterns,
public activity, and meteorological characteristics affecting ozone
formation and dispersion. Thus, spatial scale of representativeness
was not used in the selection process but was a result of site
location.
(d) In some cases, the physical location of a site is determined
from joint consideration of both the basic monitoring objective and
the type of monitoring site desired, or required by this appendix.
For example, to determine PM2.5 concentrations which are
typical over a geographic area having relatively high
PM2.5 concentrations, a neighborhood scale site is more
appropriate. Such a site would likely be located in a residential or
commercial area having a high overall PM2.5 emission
density but not in the immediate vicinity of any single dominant
source. Note that in this example, the desired scale of
representativeness was an important factor in determining the
physical location of the monitoring site.
(e) In either case, classification of the monitor by its type
and spatial scale of representativeness is necessary and will aid in
interpretation of the monitoring data for a particular monitoring
objective (e.g., public reporting, NAAQS compliance, or research
support).
(f) Table D-1 of this appendix illustrates the relationship
between the various site types that can be used to support the three
basic monitoring objectives, and the scales of representativeness
that are generally most appropriate for that type of site.
Table D-1 of Appendix D to Part 58. Relationship Between Site Types and
Scales of Representativeness
------------------------------------------------------------------------
Site type Appropriate siting scales
------------------------------------------------------------------------
1. Highest concentration.................. Micro, middle, neighborhood
(sometimes urban or
regional for secondarily
formed pollutants).
2. Population oriented.................... Neighborhood, urban.
3. Source impact.......................... Micro, middle, neighborhood.
4. General/background & regional transport Urban, regional.
5. Welfare-related impacts................ Urban, regional.
------------------------------------------------------------------------
2. General Monitoring Requirements
(a) The National ambient air monitoring system includes several
types of monitoring stations, each targeting a key data collection
need and each varying in technical sophistication.
(b) Research grade sites are platforms for scientific studies,
either involved with health or welfare impacts, measurement methods
development, or other atmospheric studies. These sites may be
collaborative efforts between regulatory agencies and researchers
with specific scientific objectives for each. Data from these sites
might be collected with both traditional and experimental
techniques, and data collection might involve specific laboratory
analyses not common in routine measurement programs. The research
grade sites are not required by regulation; however, they are
included here due to their important role in supporting the air
quality management program.
(c) The NCore multipollutant sites are sites that measure
multiple pollutants in order to provide support to integrated air
quality management data needs. NCore sites include both neighborhood
and urban scale measurements in general, in a selection of
metropolitan areas and a limited number of more rural locations.
Continuous monitoring methods are to be used at the NCore sites when
available for a pollutant to be measured, as it is important to have
data collected over common time periods for integrated analyses.
NCore multipollutant sites are intended to be long-term sites useful
for a variety of applications including air quality trends analyses,
model evaluation, and tracking metropolitan area statistics. As
such, the NCore sites should be placed away from direct emission
sources that could substantially impact the ability to detect area-
wide concentrations. The Administrator must approve the NCore sites.
(d) Monitoring sites designated as SLAMS sites, but not as NCore
sites, are intended to address specific air quality management
interests, and as such, are frequently single-pollutant measurement
sites. The EPA Regional Administrator must approve the SLAMS sites.
(e) This appendix uses the statistical-based definitions for
metropolitan areas provided by the Office of Management and Budget
and the Census Bureau. These areas are referred to as metropolitan
statistical areas (MSA), micropolitan statistical areas, core-based
statistical areas (CBSA), and combined statistical areas (CSA). A
CBSA associated with at least one urbanized area of 50,000
population or greater is termed a Metropolitan Statistical Area
(MSA). A CBSA associated with at least one urbanized cluster of at
least 10,000 population or greater is termed a Micropolitan
Statistical Area. CSA consist of two or more adjacent CBSA. In this
appendix, the term MSA is used to refer to a Metropolitan
Statistical Area. By definition, both MSA and CSA have a high degree
of integration; however, many such areas cross State or other
political boundaries. MSA and CSA may also cross more than one air
shed. The EPA recognizes that State or local agencies must consider
MSA/CSA boundaries and their own political boundaries and
geographical characteristics in designing their air monitoring
networks. The EPA recognizes that there may be situations where the
EPA Regional Administrator and the affected State or local agencies
may need to augment or to divide the overall MSA/CSA monitoring
responsibilities and requirements among these various agencies to
achieve an effective network design. Full monitoring requirements
apply separately to each affected State or local agency in the
absence of an agreement between the affected agencies and the EPA
Regional Administrator.
3. Design Criteria for NCore Sites
(a) Each State (i.e. the fifty States, District of Columbia,
Puerto Rico, and the Virgin Islands) is required to operate at least
one NCore site. States may delegate this requirement to a local
agency. States with many MSAs often also have multiple air sheds
with unique characteristics and, often, elevated air pollution.
These States include, at a minimum, California, Florida, Illinois,
Michigan, New York, North Carolina, Ohio, Pennsylvania, and Texas.
These States are required to identify one to two additional NCore
sites in order to account for their unique situations. These
additional sites shall be located to avoid proximity to large
emission sources. Any State or local agency can propose additional
candidate NCore sites or modifications to these requirements for
approval by the Administrator. The NCore locations should be
leveraged with other multipollutant air monitoring sites including
PAMS sites, National Air Toxics Trends Stations (NATTS) sites,
CASTNET sites, and STN sites. Site leveraging includes using the
same monitoring platform and equipment to meet the objectives of the
variety of programs where possible and advantageous.
(b) The NCore sites must measure, at a minimum, PM2.5
particle mass using continuous and integrated/filter-based samplers,
speciated PM2.5, PM10-2.5 particle mass,
speciated PM10-2.5, O3, SO2, CO,
NO/NOy, wind speed, wind direction, relative humidity,
and ambient temperature.
(1) Although the measurement of NOy is required in
support of a number of monitoring objectives, available commercial
instruments may indicate little difference in their measurement of
NOy compared to the conventional measurement of
NOX, particularly in areas with relatively fresh sources
of nitrogen emissions. Therefore, in areas with negligible expected
difference between NOy and NOX measured
concentrations, the Administrator may allow
[[Page 61318]]
for waivers that permit NOX monitoring to be substituted
for the required NOy monitoring at applicable NCore
sites.
(2) EPA recognizes that, in some cases, the physical location of
the NCore site may not be suitable for representative meteorological
measurements due to the site's physical surroundings. It is also
possible that nearby meteorological measurements may be able to
fulfill this data need. In these cases, the requirement for
meteorological monitoring can be waived by the Administrator.
(c) In addition to the continuous measurements listed above, 10
of the NCore locations must also measure lead (Pb) either at the
same sites or elsewhere within the MSA/CSA boundary. These ten Pb
sites are included within the NCore networks because they are
intended to be long-term in operation, and not impacted directly
from a single Pb source. These locations for Pb monitoring must be
located in the most populated MSA/CSA in each of the 10 EPA Regions.
Alternatively, it is also acceptable to use the Pb concentration
data provided at urban air toxics sites. In approving any
substitutions, the Administrator must consider whether these
alternative sites are suitable for collecting long-term lead trends
data for the broader area.
(d) Siting criteria are provided for urban and rural locations.
Sites with significant historical records that do not meet siting
criteria may be approved as NCore by the Administrator. Sites with
the suite of NCore measurements that are explicitly designed for
other monitoring objectives are exempt from these siting criteria
(e.g., a near-roadway site).
(1) Urban NCore stations are to be generally located at urban or
neighborhood scale to provide representative concentrations of
exposure expected throughout the metropolitan area; however, a
middle-scale site may be acceptable in cases where the site can
represent many such locations throughout a metropolitan area.
(2) Rural NCore stations are to be located to the maximum extent
practicable at a regional or larger scale away from any large local
emission source, so that they represent ambient concentrations over
an extensive area.
4. Pollutant-Specific Design Criteria for SLAMS Sites
4.1 Ozone (O3) Design Criteria. (a) State, and where
appropriate, local agencies must operate O3 sites for
various locations depending upon area size (in terms of population
and geographic characteristics) and typical peak concentrations
(expressed in percentages below, or near the O3 NAAQS).
Specific SLAMS O3 site minimum requirements are included
in Table D-2 of this appendix. The NCore sites are expected to
complement the O3 data collection that takes place at
single-pollutant SLAMS sites, and both types of sites can be used to
meet the network minimum requirements. The total number of
O3 sites needed to support the basic monitoring
objectives of public data reporting, air quality mapping,
compliance, and understanding O3-related atmospheric
processes will include more sites than these minimum numbers
required in Table D-2 of this appendix. The EPA Regional
Administrator and the responsible State or local air monitoring
agency must work together to design and/or maintain the most
appropriate O3 network to service the variety of data
needs in an area.
Table D-2 of Appendix D to Part 58.-- SLAMS Minimum O3 Monitoring
Requirements
------------------------------------------------------------------------
Most recent 3-year Most recent 3-year
design value design value
MSA population1, 2 concentrations concentrations
>=85% of any O3 <85% of any O3
NAAQS 3 NAAQS3, 4
------------------------------------------------------------------------
>10 million..................... 4 2
4-10 million.................... 3 1
350,000-<4 million.............. 2 1
50,000-<350,000 5............... 1 0
------------------------------------------------------------------------
\1\ Minimum monitoring requirements apply to the Metropolitan
statistical area (MSA).
\2\ Population based on latest available census figures.
\3\ The ozone (O3) National Ambient Air Quality Standards (NAAQS) levels
and forms are defined in 40 CFR part 50.
\4\ These minimum monitoring requirements apply in the absence of a
design value.
\5\ Metropolitan statistical areas (MSA) must contain an urbanized area
of 50,000 or more population.
(b) Within an O3 network, at least one O3
site for each MSA, or CSA if multiple MSAs are involved, must be
designed to record the maximum concentration for that particular
metropolitan area. More than one maximum concentration site may be
necessary in some areas. Table D-2 of this appendix does not account
for the full breadth of additional factors that would be considered
in designing a complete O3 monitoring program for an
area. Some of these additional factors include geographic size,
population density, complexity of terrain and meteorology, adjacent
O3 monitoring programs, air pollution transport from
neighboring areas, and measured air quality in comparison to all
forms of the O3 NAAQS (i.e., 8-hour and 1-hour forms).
Networks must be designed to account for all of these area
characteristics. Network designs must be re-examined in periodic
network assessments. Deviations from the above O3
requirements are allowed if approved by the EPA Regional
Administrator.
(c) The appropriate spatial scales for O3 sites are
neighborhood, urban, and regional. Since O3 requires
appreciable formation time, the mixing of reactants and products
occurs over large volumes of air, and this reduces the importance of
monitoring small scale spatial variability.
(1) Neighborhood scale--Measurements in this category represent
conditions throughout some reasonably homogeneous urban sub-region,
with dimensions of a few kilometers. Homogeneity refers to pollutant
concentrations. Neighborhood scale data will provide valuable
information for developing, testing, and revising concepts and
models that describe urban/regional concentration patterns. These
data will be useful to the understanding and definition of processes
that take periods of hours to occur and hence involve considerable
mixing and transport. Under stagnation conditions, a site located in
the neighborhood scale may also experience peak concentration levels
within a metropolitan area.
(2) Urban scale--Measurement in this scale will be used to
estimate concentrations over large portions of an urban area with
dimensions of several kilometers to 50 or more kilometers. Such
measurements will be used for determining trends, and designing
area-wide control strategies. The urban scale sites would also be
used to measure high concentrations downwind of the area having the
highest precursor emissions.
(3) Regional scale--This scale of measurement will be used to
typify concentrations over large portions of a metropolitan area and
even larger areas with dimensions of as much as hundreds of
kilometers. Such measurements will be useful for assessing the
O3 that is transported to and from a metropolitan area,
as well as background concentrations. In some situations,
particularly when considering very large metropolitan areas with
complex source mixtures, regional scale sites can be the maximum
concentration location.
(d) EPA's technical guidance documents on O3
monitoring network design should be used to evaluate the adequacy of
each existing O3 monitor, to relocate an existing site,
or to locate any new O3 sites.
(e) For locating a neighborhood scale site to measure typical
city concentrations, a reasonably homogeneous geographical area near
the center of the region should be selected which is also removed
from the influence of major NOX sources. For an urban
scale site to measure the high concentration areas, the emission
inventories should be
[[Page 61319]]
used to define the extent of the area of important nonmethane
hydrocarbons and NOX emissions. The meteorological
conditions that occur during periods of maximum photochemical
activity should be determined. These periods can be identified by
examining the meteorological conditions that occur on the highest
O3 air quality days. Trajectory analyses, an evaluation
of wind and emission patterns on high O3 days, can also
be useful in evaluating an O3 monitoring network. In
areas without any previous O3 air quality measurements,
meteorological and O3 precursor emissions information
would be useful.
(f) Once the meteorological and air quality data are reviewed,
the prospective maximum concentration monitor site should be
selected in a direction from the city that is most likely to observe
the highest O3 concentrations, more specifically,
downwind during periods of photochemical activity. In many cases,
these maximum concentration O3 sites will be located 10
to 30 miles or more downwind from the urban area where maximum
O3 precursor emissions originate. The downwind direction
and appropriate distance should be determined from historical
meteorological data collected on days which show the potential for
producing high O3 levels. Monitoring agencies are to
consult with their EPA Regional Office when considering siting a
maximum O3 concentration site.
(g) In locating a neighborhood scale site which is to measure
high concentrations, the same procedures used for the urban scale
are followed except that the site should be located closer to the
areas bordering on the center city or slightly further downwind in
an area of high density population.
(h) For regional scale background monitoring sites, similar
meteorological analysis as for the maximum concentration sites may
also inform the decisions for locating regional scale sites.
Regional scale sites may be located to provide data on O3
transport between cities, as background sites, or for other data
collection purposes. Consideration of both area characteristics,
such as meteorology, and the data collection objectives, such as
transport, must be jointly considered for a regional scale site to
be useful.
(i) Since O3 levels decrease significantly in the
colder parts of the year in many areas, O3 is required to
be monitored at SLAMS monitoring sites only during the ``ozone
season'' as designated in the AQS files on a State-by-State basis
and described below in Table D-3 of this appendix. Deviations from
the O3 monitoring season must be approved by the EPA
Regional Administrator, documented within the annual monitoring
network plan, and updated in AQS. Information on how to analyze
O3 data to support a change to the O3 season
in support of the 8-hour standard for a specific State can be found
in reference 8 to this appendix.
Table D-3 to Appendix D of Part 58. Ozone Monitoring Season by State
------------------------------------------------------------------------
State Begin month End month
------------------------------------------------------------------------
Alabama......................... March............. October
Alaska.......................... April............. October
Arizona......................... January........... December
Arkansas........................ March............. November
California...................... January........... December
Colorado........................ March............. September
Connecticut..................... April............. September
Delaware........................ April............. October
District of Columbia............ April............. October
Florida......................... March............. October
Georgia......................... March............. October
Hawaii.......................... January........... December
Idaho........................... May............... September
Illinois........................ April............. October
Indiana......................... April............. September
Iowa............................ April............. October
Kansas.......................... April............. October
Kentucky........................ March............. October
Louisiana AQCR 019,022.......... March............. October
Louisiana AQCR 106.............. January........... December
Maine........................... April............. September
Maryland........................ April............. October
Massachusetts................... April............. September
Michigan........................ April............. September
Minnesota....................... April............. October
Mississippi..................... March............. October
Missouri........................ April............. October
Montana......................... June.............. September
Nebraska........................ April............. October
Nevada.......................... January........... December
New Hampshire................... April............. September
New Jersey...................... April............. October
New Mexico...................... January........... December
New York........................ April............. October
North Carolina.................. April............. October
North Dakota.................... May............... September
Ohio............................ April............. October
Oklahoma........................ March............. November
Oregon.......................... May............... September
Pennsylvania.................... April............. October
Puerto Rico..................... January........... December
Rhode Island.................... April............. September
South Carolina.................. April............. October
South Dakota.................... June.............. September
Tennessee....................... March............. October
Texas AQCR 106,153, 213, 214, January........... December
216.
Texas AQCR 022, 210, 211, 212, March............. October
215, 217, 218.
Utah............................ May............... September
Vermont......................... April............. September
Virginia........................ April............. October
Washington...................... May............... September
West Virginia................... April............. October
Wisconsin....................... April 15.......... October 15
Wyoming......................... April............. October
American Samoa.................. January........... December
Guam............................ January........... December
Virgin Islands.................. January........... December
------------------------------------------------------------------------
4.2 Carbon Monoxide (CO) Design Criteria. (a) There are no
minimum requirements for the number of CO monitoring sites.
Continued operation of existing SLAMS CO sites using FRM or FEM is
required until discontinuation is approved by the EPA Regional
Administrator. Where SLAMS CO monitoring is ongoing, at least one
site must be a maximum concentration site for that area under
investigation.
(b) Microscale and middle scale measurements are useful site
classifications for SLAMS sites since most people have the potential
for exposure on these scales. Carbon monoxide maxima occur primarily
in areas near major roadways and intersections with high traffic
density and often poor atmospheric ventilation.
(1) Microscale--This scale applies when air quality measurements
are to be used to represent distributions within street canyons,
over sidewalks, and near major roadways. In the case with carbon
monoxide, microscale measurements in one location can often be
considered as representative of other similar locations in a city.
(2) Middle scale--Middle scale measurements are intended to
represent areas with dimensions from 100 meters to 0.5 kilometer. In
certain cases, middle scale measurements may apply to areas that
have a total length of several kilometers, such as ``line'' emission
source areas. This type of emission sources areas would include air
quality along a commercially developed street or shopping plaza,
freeway corridors, parking lots and feeder streets.
(c) After the spatial scale and type of site has been determined
to meet the monitoring objective for each location, the technical
guidance in reference 2 of this appendix should be used to evaluate
the adequacy of each existing CO site and must be used to relocate
an existing site or to locate any new sites.
4.3 Nitrogen Dioxide (NO2) Design Criteria. (a) There
are no minimum requirements for the number of NO2
monitoring sites. Continued operation of existing SLAMS
NO2 sites using FRM or FEM is required until
discontinuation is approved by the EPA Regional Administrator. Where
SLAMS NO2 monitoring is ongoing, at least one
NO2 site in the area must be located to measure the
maximum concentration of NO2.
(b) NO/NOy measurements are included within the NCore
multipollutant site requirements and the PAMS program. These NO/
NOy measurements will produce conservative estimates for
NO2 that can be used to ensure tracking continued
compliance with the NO2 NAAQS. NO/NOy monitors
are used at these sites because it is important to collect data on
total reactive nitrogen species for understanding O3
photochemistry.
4.4 Sulfur Dioxide (SO2) Design Criteria. (a) There
are no minimum requirements for the number of SO2
monitoring sites. Continued operation of existing SLAMS
SO2 sites using FRM or FEM is required until
discontinuation is approved by the EPA Regional Administrator. Where
SLAMS SO2 monitoring is ongoing, at least one of the
SLAMS SO2 sites must be a maximum concentration site for
that specific area.
(b) The appropriate spatial scales for SO2 SLAMS
monitoring are the microscale, middle, and possibly neighborhood
scales. The multi-pollutant NCore sites can provide
[[Page 61320]]
for metropolitan area trends analyses and general control strategy
progress tracking. Other SLAMS sites are expected to provide data
that are useful in specific compliance actions, for maintenance plan
agreements, or for measuring near specific stationary sources of
SO2.
(1) Micro and middle scale--Some data uses associated with
microscale and middle scale measurements for SO2 include
assessing the effects of control strategies to reduce concentrations
(especially for the 3-hour and 24-hour averaging times) and
monitoring air pollution episodes.
(2) Neighborhood scale--This scale applies where there is a need
to collect air quality data as part of an ongoing SO2
stationary source impact investigation. Typical locations might
include suburban areas adjacent to SO2 stationary sources
for example, or for determining background concentrations as part of
these studies of population responses to exposure to SO2.
(c) Technical guidance in reference 1 of this appendix should be
used to evaluate the adequacy of each existing SO2 site,
to relocate an existing site, or to locate new sites.
4.5 Lead (Pb) Design Criteria. (a) State, and where appropriate,
local agencies are required to conduct Pb monitoring for all areas
where Pb levels have been shown or are expected to be of concern
over the most recent 2 years. As a minimum, there must be two SLAMS
sites in any area where Pb concentrations currently exceed or have
exceeded the Pb NAAQS in the most recent 2 years, and at least one
of these two required sites must be a maximum concentration site.
Where the Pb air quality violations are widespread or the emissions
density, topography, or population locations are complex and varied,
the EPA Regional Administrator may require more than two Pb ambient
air monitoring sites.
(b) The most important spatial scales to effectively
characterize the emissions from point sources are the micro, middle,
and neighborhood scales.
(1) Microscale--This scale would typify areas in close proximity
to lead point sources. Emissions from point sources such as primary
and secondary lead smelters, and primary copper smelters may under
fumigation 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 sites provide information for evaluating and developing
``hot-spot'' control measures.
(2) Middle scale--This scale generally represents Pb air quality
levels in areas up to several city blocks in size with dimensions on
the order of approximately 100 meters to 500 meters. The middle
scale may for example, include schools and playgrounds in center
city areas which are close to major Pb point sources. Pb monitors in
such areas are desirable because of the higher sensitivity of
children to exposures of elevated Pb concentrations (reference 3 of
this appendix). Emissions from point sources frequently impact on
areas at which single sites may be located to measure concentrations
representing middle spatial scales.
(3) Neighborhood scale--The neighborhood scale would
characterize air quality conditions throughout some relatively
uniform land use areas with dimensions in the 0.5 to 4.0 kilometer
range. Sites of this scale would provide monitoring data in areas
representing conditions where children live and play. Monitoring in
such areas is important since this segment of the population is more
susceptible to the effects of Pb. Where a neighborhood site is
located away from immediate Pb sources, the site may be very useful
in representing typical air quality values for a larger residential
area, and therefore suitable for population exposure and trends
analyses.
(c) Technical guidance is found in references 4 and 5 of this
appendix. These documents provide additional guidance on locating
sites to meet specific urban area monitoring objectives and should
be used in locating new sites or evaluating the adequacy of existing
sites.
4.6 Particulate Matter (PM10) Design Criteria. (a)
State, and where applicable local, agencies must operate the minimum
number of required PM10 SLAMS sites listed in Table D-4
of this appendix.
Table D-4 of Appendix D to Part 58. PM10 Minimum Monitoring Requirements (Number of Stations per MSA) \1\
----------------------------------------------------------------------------------------------------------------
High concentration Medium Low concentration
Population category \2\ concentration \3\ \4,5\
----------------------------------------------------------------------------------------------------------------
>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 numbers of stations per area within the ranges shown in this table 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 the
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.
\5\ These minimum monitoring requirements apply in the absence of a design value.
(b) Although microscale monitoring may be appropriate in some
circumstances, the most important spatial scales to effectively
characterize the emissions of PM10 from both mobile and
stationary sources are the middle scales and neighborhood scales.
(1) Microscale--This scale would typify areas such as downtown
street canyons, traffic corridors, and fence line stationary source
monitoring locations where the general public could be exposed to
maximum PM10 concentrations. 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 sites provide information for evaluating and
developing hot spot control measures.
(2) Middle scale--Much of the short-term public exposure to
coarse fraction particles (PM10) is on this scale and on
the neighborhood scale. People moving through downtown areas or
living near major roadways or stationary sources, may encounter
particulate pollution that would be adequately characterized by
measurements of this spatial scale. Middle scale PM10
measurements can be appropriate for the evaluation of possible
short-term exposure public health effects. 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
seldomly swept parking lots associated with these sources could be
an important source
[[Page 61321]]
in addition to the vehicular emissions themselves.
(3) Neighborhood scale--Measurements in this category represent
conditions throughout some reasonably homogeneous urban sub-region
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. 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. Neighborhood scale PM10 sites
provide information about trends and compliance with standards
because they often represent conditions in areas where people
commonly live and work for extended periods. 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.
4.7 Fine Particulate Matter (PM2.5) Design Criteria.
4.7.1 General Requirements. (a) State, and where applicable
local, agencies must operate the minimum number of required
PM2.5 SLAMS sites listed in Table D-5 of this appendix.
The NCore sites are expected to complement the PM2.5 data
collection that takes place at non-NCore SLAMS sites, and both types
of sites can be used to meet the minimum PM2.5 network
requirements. Deviations from these PM2.5 monitoring
requirements must be approved by the EPA Regional Administrator.
Table D-5 of Appendix D to Part 58. PM2.5 Minimum Monitoring
Requirements
------------------------------------------------------------------------
Most recent 3-year Most recent 3-year
design value >=85% design value <85%
MSA population \1,2\ of any PM2.5 NAAQS of any PM2.5 NAAQS
\3\ \3\, \4\
------------------------------------------------------------------------
>1,000,000...................... 3 2
500,000-1,000,000............... 2 1
50,000-<500,000 \5\............. 1 0
------------------------------------------------------------------------
\1\ Minimum monitoring requirements apply to the Metropolitan
statistical area (MSA).
\2\ Population based on latest available census figures.
\3\ The PM2.5 National Ambient Air Quality Standards (NAAQS) levels and
forms are defined in 40 CFR part 50.
\4\ These minimum monitoring requirements apply in the absence of a
design value.
\5\ Metropolitan statistical areas (MSA) must contain an urbanized area
of 50,000 or more population.
(b) Specific Design Criteria for PM2.5. The required
monitoring stations or sites must be sited to represent community-
wide air quality. These sites can include sites collocated at PAMS.
These monitoring stations will typically be at neighborhood or
urban-scale; however, in certain instances where population-oriented
micro-or middle-scale PM2.5 monitoring are determined by
the Regional Administrator to represent many such locations
throughout a metropolitan area, these smaller scales can be
considered to represent community-wide air quality.
(1) At least one monitoring station is to be sited in a
population-oriented area of expected maximum concentration.
(2) For areas with more than one required SLAMS, a monitoring
station is to be sited in an area of poor air quality.
(3) Additional technical guidance for siting PM2.5
monitors is provided in references 6 and 7 of this appendix.
(c) The most important spatial scale to effectively characterize
the emissions of particulate matter from both mobile and stationary
sources is the neighborhood scale for PM2.5. For purposes
of establishing monitoring sites to represent large homogenous areas
other than the above scales of representativeness and to
characterize regional transport, urban or regional scale sites would
also be needed. Most PM2.5 monitoring in urban areas
should be representative of a neighborhood scale.
(1) 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 sites;
community-oriented SLAMS sites measured at the microscale level
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 sites 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 SPM.
(2) Middle scale--People moving through downtown areas, or
living near major roadways, encounter particle concentrations that
would be adequately characterized by 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 microscale 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 number
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.
(3) Neighborhood scale--Measurements in this category would
represent conditions throughout some reasonably homogeneous urban
sub-region 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 the immediate neighborhood as well as
neighborhoods of the same type in other parts of the city.
PM2.5 sites 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.
(4) Urban scale--This class of measurement would be used to
characterize the particulate matter concentration over an entire
metropolitan or rural area ranging in size from 4 to 50 kilometers.
Such measurements would be useful for assessing trends in area-wide
air quality, and hence, the effectiveness of large scale air
pollution control strategies. Community-oriented PM2.5
sites may have this scale.
(5) 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. Data characteristics of this scale would
provide information about larger scale processes of particulate
matter
[[Page 61322]]
emissions, losses and transport. PM2.5 transport
contributes to elevated 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 O3 and regional
haze.
4.7.2 Requirement for Continuous PM2.5 Monitoring.
State, or where appropriate, local agencies must operate continuous
fine particulate analyzers equal to at least one-half (round up) the
minimum required sites listed in Table D-5 of this appendix. At
least one required FRM/FEM monitor in each MSA must be collocated.
State and local air monitoring agencies must use methodologies and
quality assurance/quality control(QA/QC) procedures approved by the
EPA Regional Administrator for these sites.
4.7.3 Requirement for PM2.5 Background and Transport
Sites. Each State shall install and operate at least one
PM2.5 site to monitor for regional background and at
least one PM2.5 site to monitor regional transport. These
monitoring sites may be at community-oriented sites and this
requirement may be satisfied by a corresponding monitor in an area
having similar air quality in another State. State and local air
monitoring agencies must use methodologies and QA/QC procedures
approved by the EPA Regional Administrator for these sites. Methods
used at these sites may include non-federal reference method
samplers such as IMPROVE or continuous PM2.5 monitors.
4.7.4 PM2.5 Chemical Speciation Site Requirements.
Each State shall continue to conduct chemical speciation monitoring
and analyses at sites designated to be part of the PM2.5
Speciation Trends Network (STN). The selection and modification of
these STN sites must be approved by the Administrator. The
PM2.5 chemical speciation urban trends sites shall
include analysis for elements, selected anions and cations, and
carbon. Samples must be collected using the monitoring methods and
the sampling schedules approved by the Administrator. Chemical
speciation is encouraged at additional sites where the chemically
resolved data would be useful in developing State implementation
plans and supporting atmospheric or health effects related studies.
4.7.5 Special Network Considerations Required When Using
PM2.5 Spatial Averaging Approaches. (a) The
PM2.5 NAAQS, specified in 40 CFR part 50, provides State
and local air monitoring agencies with an option for spatially
averaging PM2.5 air quality data. More specifically, two
or more community-oriented (i.e., sites in populated areas)
PM2.5 monitors may be averaged for comparison with the
annual PM2.5 NAAQS. This averaging approach is directly
related to epidemiological studies used as the basis for the
PM2.5 annual NAAQS. Spatial averaging does not apply to
comparisons with the daily PM2.5 NAAQS.
(b) State and local agencies must carefully consider their
approach for PM2.5 network design when they intend to
spatially average the data for compliance purposes. These State and
local air monitoring agencies must define the area over which they
intend to average PM2.5 air quality concentrations. This
area is defined as a Community Monitoring Zone (CMZ), which
characterizes an area of relatively similar annual average air
quality. State and local agencies can define a CMZ in a number of
ways, including as part or all of a metropolitan area. These CMZ
must be defined within a State or local agencies network
description, as required in Sec. 58.10 of this part and approved by
the EPA Regional Administrator. When more than one CMZ is described
within an agency's network design plan, CMZs must not overlap in
their geographical coverage. The criteria that must be used for
evaluating the acceptability of spatial averaging are defined in
appendix N to 40 CFR part 50.
4.8 Coarse Particulate Matter (PM10-2.5) Design
Criteria.
4.8.1 General Monitoring Requirements. (a) The only required
monitors for PM10-2.5 are those required at NCore
Stations.
(b) Although microscale monitoring may be appropriate in some
circumstances, middle and neighborhood scale measurements are the
most important station classifications for PM10-2.5 to
assess the variation in coarse particle concentrations that would be
expected across populated areas that are in proximity to large
emissions sources.
(1) Microscale--This scale would typify relatively small areas
immediately adjacent to: Industrial sources; locations experiencing
ongoing construction, redevelopment, and soil disturbance; and
heavily traveled roadways. Data collected at microscale stations
would characterize exposure over areas of limited spatial extent and
population exposure, and may provide information useful for
evaluating and developing source-oriented control measures.
(2) Middle scale--People living or working near major roadways
or industrial districts encounter particle concentrations that would
be adequately characterized by this spatial scale. Thus,
measurements of this type would be appropriate for the evaluation of
public health effects of coarse particle exposure. Monitors located
in populated areas that are nearly adjacent to large industrial
point sources of coarse particles provide suitable locations for
assessing maximum population exposure levels and identifying areas
of potentially poor air quality. Similarly, monitors located in
populated areas that border dense networks of heavily-traveled
traffic are appropriate for assessing the impacts of resuspended
road dust. This scale also includes the characteristic
concentrations for other areas with dimensions of a few hundred
meters such as school grounds and parks that are nearly adjacent to
major roadways and industrial point sources, locations exhibiting
mixed residential and commercial development, and downtown areas
featuring office buildings, shopping centers, and stadiums.
(3) Neighborhood scale--Measurements in this category would
represent conditions throughout some reasonably homogeneous urban
sub-region 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. This category includes suburban
neighborhoods dominated by residences that are somewhat distant from
major roadways and industrial districts but still impacted by urban
sources, and areas of diverse land use where residences are
interspersed with commercial and industrial neighborhoods. In some
cases, a location carefully chosen to provide neighborhood scale
data would represent the immediate neighborhood as well as
neighborhoods of the same type in other parts of the city. The
comparison of data from middle scale and neighborhood scale sites
would provide valuable information for determining the variation of
PM10-2.5 levels across urban areas and assessing the
spatial extent of elevated concentrations caused by major industrial
point sources and heavily traveled roadways. Neighborhood scale
sites would provide concentration data that are relevant to
informing a large segment of the population of their exposure levels
on a given day.
4.8.2 PM10-2.5 Chemical Speciation Site Requirements.
PM10-2.5 chemical speciation monitoring and analyses is
required at NCore sites. The selection and modification of these
sites must be approved by the Administrator. Samples must be
collected using the monitoring methods and the sampling schedules
approved by the Administrator.
5. Network Design for Photochemical Assessment Monitoring Stations
(PAMS)
The PAMS program provides more comprehensive data on
O3 air pollution in areas classified as serious, severe,
or extreme nonattainment for O3 than would otherwise be
achieved through the NCore and SLAMS sites. More specifically, the
PAMS program includes measurements for O3, oxides of
nitrogen, VOC, and meteorology.
5.1 PAMS Monitoring Objectives. PAMS design criteria are site
specific. Concurrent measurements of O3, oxides of
nitrogen, speciated VOC, CO, and meteorology are obtained at PAMS
sites. Design criteria for the PAMS network are based on locations
relative to O3 precursor source areas and predominant
wind directions associated with high O3 events. Specific
monitoring objectives are associated with each location. The overall
design should enable characterization of precursor emission sources
within the area, transport of O3 and its precursors, and
the photochemical processes related to O3 nonattainment.
Specific objectives that must be addressed include assessing ambient
trends in O3, oxides of nitrogen, VOC species, and
determining spatial and diurnal variability of O3, oxides
of nitrogen, and VOC species. Specific monitoring objectives
associated with each of these sites may result in four distinct site
types. Detailed guidance for the locating of these sites may be
found in reference 9 of this appendix.
(a) Type 1 sites are established to characterize upwind
background and transported O3 and its precursor
concentrations entering the area and will identify those areas which
are subjected to transport.
[[Page 61323]]
(b) Type 2 sites are established to monitor the magnitude and
type of precursor emissions in the area where maximum precursor
emissions are expected to impact and are suited for the monitoring
of urban air toxic pollutants.
(c) Type 3 sites are intended to monitor maximum O3
concentrations occurring downwind from the area of maximum precursor
emissions.
(d) Type 4 sites are established to characterize the downwind
transported O3 and its precursor concentrations exiting
the area and will identify those areas which are potentially
contributing to overwhelming transport in other areas.
5.2 Monitoring Period. PAMS precursor monitoring must be
conducted annually throughout the months of June, July and August
(as a minimum) when peak O3 values are expected in each
area. Alternate precursor monitoring periods may be submitted for
approval to the Administrator as a part of the annual monitoring
network plan required by Sec. 58.10.
5.3 Minimum Monitoring Network Requirements. A Type 2 site is
required for each area. Overall, only two sites are required for
each area, providing all chemical measurements are made. For
example, if a design includes two Type 2 sites, then a third site
will be necessary to capture the NOy measurement. The
minimum required number and type of monitoring sites and sampling
requirements are listed in Table D-6 of this appendix. Any
alternative plans may be put in place in lieu of these requirements,
if approved by the Administrator.
Table D-6 of Appendix D to Part 58. Minimum Required PAMS Monitoring
Locations and Frequencies
------------------------------------------------------------------------
Sampling frequency
(all daily except for
Measurement Where required upper air
meteorology) \1\
------------------------------------------------------------------------
Speciated VOC2............ Two sites per area, During the PAMS
one of which must be monitoring period:
a Type 2 site. (1) Hourly auto GC,
or (2) Eight 3-hour
canisters, or (3) 1
morning and 1
afternoon canister
with a 3-hour or
less averaging time
plus Continuous
Total Non-methane
Hydrocarbon
measurement.
Carbonyl sampling......... Type 2 site in areas 3-hour samples every
classified as day during the PAMS
serious or above for monitoring period.
the 8-hour ozone
standard.
NOX....................... All Type 2 sites..... Hourly during the
ozone monitoring
season.\3\
NOy....................... One site per area at Hourly during the
the Type 3 or Type 1 ozone monitoring
site. season.
CO (ppb level)............ One site per area at Hourly during the
a Type 2 site. ozone monitoring
season.
Ozone..................... All sites............ Hourly during the
ozone monitoring
season.
Surface met............... All sites............ Hourly during the
ozone monitoring
season.
Upper air meteorology..... One representative Sampling frequency
location within PAMS must be approved as
area. part of the annual
monitoring network
plan required in 40
CFR 58.10.
------------------------------------------------------------------------
\1\ Daily or with an approved alternative plan.
\2\ Speciated VOC is defined in the ``Technical Assistance Document for
Sampling and Analysis of Ozone Precursors'', EPA/600-R-98/161,
September 1998.
\3\ Approved ozone monitoring season as stipulated in Table D-3 of this
appendix.
5.4 Transition Period. A transition period is allowed for
phasing in the operation of newly required PAMS programs (due
generally to reclassification of an area into serious, severe, or
extreme nonattainment for ozone). Following the date of
redesignation or reclassification of any existing O3
nonattainment area to serious, severe, or extreme, or the
designation of a new area and classification to serious, severe, or
extreme O3 nonattainment, a State is allowed 1 year to
develop plans for its PAMS implementation strategy. Subsequently, a
minimum of one Type 2 site must be operating by the first month of
the following approved PAMS season. Operation of the remaining
site(s) must, at a minimum, be phased in at the rate of one site per
year during subsequent years as outlined in the approved PAMS
network description provided by the State.
6. References
1. Ball, R.J. and G.E. Anderson. Optimum Site Exposure Criteria
for SO2 Monitoring. The Center for the Environment and
Man, Inc., Hartford, CT. Prepared for U.S. Environmental Protection
Agency, Research Triangle Park, NC. EPA Publication No. EPA-450/3-
77-013. April 1977.
2. Ludwig, F.F., J.H.S. Kealoha, and E. Shelar. Selecting Sites
for Carbon Monoxide Monitoring. Stanford Research Institute, Menlo
Park, CA. Prepared for U.S. Environmental Protection Agency,
Research Triangle Park, NC. EPA Publication No. EPA-450/3-75-077,
September 1975.
3. Air Quality Criteria for Lead. Office of Research and
Development, U.S. Environmental Protection Agency, Washington D.C.
EPA Publication No. 600/8-89-049F. August 1990. (NTIS document
numbers PB87-142378 and PB91-138420.)
4. Optimum Site Exposure Criteria for Lead Monitoring. PEDCo
Environmental, Inc. Cincinnati, OH. Prepared for U.S. Environmental
Protection Agency, Research Triangle Park, NC. EPA Contract No. 68-
02-3013. May 1981.
5. Guidance for Conducting Ambient Air Monitoring for Lead
Around Point Sources. Office of Air Quality Planning and Standards,
U.S. Environmental Protection Agency, Research Triangle Park, NC.
EPA-454/R-92-009. May 1997.
6. Koch, R.C. and H.E. Rector. Optimum Network Design and Site
Exposure Criteria for Particulate Matter. GEOMET Technologies, Inc.,
Rockville, MD. Prepared for U.S. Environmental Protection Agency,
Research Triangle Park, NC. EPA Contract No. 68-02-3584. EPA 450/4-
87-009. May 1987.
7. 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. EPA-
454/R-99-022, December 1997.
8. Guideline for Selecting and Modifying the Ozone Monitoring
Season Based on an 8-Hour Ozone Standard. Prepared for U.S.
Environmental Protection Agency, RTP, NC. EPA-454/R-98-001, June
1998.
9. Photochemical Assessment Monitoring Stations Implementation
Manual. Office of Air Quality Planning and Standards, U.S.
Environmental Protection Agency, Research Triangle Park, NC. EPA-
454/B-93-051. March 1994.
37. Appendix E to part 58 is revised to read as follows:
Appendix E to Part 58--Probe and Monitoring Path Siting Criteria for
Ambient Air Quality Monitoring
1. Introduction.
2. Horizontal and Vertical Placement.
3. Spacing from Minor Sources.
4. Spacing From Obstructions.
5. Spacing From Trees.
6. Spacing From Roadways.
7. Cumulative Interferences on a Monitoring Path.
8. Maximum Monitoring Path Length.
9. Probe Material and Pollutant Sample Residence Time.
10. Waiver Provisions.
11. Summary.
12. References.
1. Introduction
(a) This appendix contains specific location criteria applicable
to SLAMS, NCore, and PAMS ambient air quality monitoring probes,
inlets, and optical paths after the general location has been
selected based on the monitoring objectives and spatial scale of
representation discussed in appendix D to this part. Adherence to
these
[[Page 61324]]
siting criteria is necessary to ensure the uniform collection of
compatible and comparable air quality data.
(b) The probe and monitoring path siting criteria discussed in
this appendix must be followed to the maximum extent possible. It is
recognized that there may be situations where some deviation from
the siting criteria may be necessary. In any such case, the reasons
must be thoroughly documented in a written request for a waiver that
describes how and why the proposed siting deviates from the
criteria. This documentation should help to avoid later questions
about the validity of the resulting monitoring data. Conditions
under which the EPA would consider an application for waiver from
these siting criteria are discussed in section 10 of this appendix.
(c) The pollutant-specific probe and monitoring path siting
criteria generally apply to all spatial scales except where noted
otherwise. Specific siting criteria that are phrased with a ``must''
are defined as requirements and exceptions must be approved through
the waiver provisions. However, siting criteria that are phrased
with a ``should'' are defined as goals to meet for consistency but
are not requirements.
2. Horizontal and Vertical Placement
The probe or at least 80 percent of the monitoring path must be
located between 2 and 15 meters above ground level for all ozone,
sulfur dioxide and nitrogen dioxide monitoring sites, and for
neighborhood scale Pb, PM10, PM10-2.5,
PM2.5, and carbon monoxide sites. Middle scale
PM10-2.5 sites are required to have sampler inlets
between 2 and 7 meters above ground level. Microscale Pb,
PM10, PM10-2.5 and PM2.5 sites are
required to have sampler inlets between 2 and 7 meters above ground
level. The inlet probes for microscale carbon monoxide monitors that
are being used to measure concentrations near roadways must be
3\1/2\ meters above ground level. The probe or at least
90 percent of the monitoring path must be at least 1 meter
vertically or horizontally away from any supporting structure,
walls, parapets, penthouses, etc., and away from dusty or dirty
areas. If the probe or a significant portion of the monitoring path
is located near the side of a building, then it should be located on
the windward side of the building relative to the prevailing wind
direction during the season of highest concentration potential for
the pollutant being measured.
3. Spacing From Minor Sources
(a) It is important to understand the monitoring objective for a
particular location in order to interpret this particular
requirement. Local minor sources of a primary pollutant, such as
SO2, lead, or particles, can cause high concentrations of
that particular pollutant at a monitoring site. If the objective for
that monitoring site is to investigate these local primary pollutant
emissions, then the site is likely to be properly located nearby.
This type of monitoring site would in all likelihood be a microscale
type of monitoring site. If a monitoring site is to be used to
determine air quality over a much larger area, such as a
neighborhood or city, a monitoring agency should avoid placing a
monitor probe, path, or inlet near local, minor sources. The plume
from the local minor sources should not be allowed to
inappropriately impact the air quality data collected at a site.
Particulate matter sites should not be located in an unpaved area
unless there is vegetative ground cover year round, so that the
impact of wind blown dusts will be kept to a minimum.
(b) Similarly, local sources of nitric oxide (NO) and ozone-
reactive hydrocarbons can have a scavenging effect causing
unrepresentatively low concentrations of O3 in the
vicinity of probes and monitoring paths for O3. To
minimize these potential interferences, the probe or at least 90
percent of the monitoring path must be away from furnace or
incineration flues or other minor sources of SO2 or NO.
The separation distance should take into account the heights of the
flues, type of waste or fuel burned, and the sulfur content of the
fuel.
4. Spacing From Obstructions
(a) Buildings and other obstacles may possibly scavenge
SO2, O3, or NO2, and can act to
restrict airflow for any pollutant. To avoid this interference, the
probe, inlet, or at least 90 percent of the monitoring path must
have unrestricted airflow and be located away from obstacles. The
distance from the obstacle to the probe, inlet, or monitoring path
must be at least twice the height that the obstacle protrudes above
the probe, inlet, or monitoring path. An exception to this
requirement can be made for measurements taken in street canyons or
at source-oriented sites where buildings and other structures are
unavoidable.
(b) Generally, a probe or monitoring path located near or along
a vertical wall is undesirable because air moving along the wall may
be subject to possible removal mechanisms. A probe, inlet, or
monitoring path must have unrestricted airflow in an arc of at least
180 degrees. This arc must include the predominant wind direction
for the season of greatest pollutant concentration potential. For
particle sampling, a minimum of 2 meters of separation from walls,
parapets, and structures is required for rooftop site placement.
(c) Special consideration must be given to the use of open path
analyzers due to their inherent potential sensitivity to certain
types of interferences, or optical obstructions. A monitoring path
must be clear of all trees, brush, buildings, plumes, dust, or other
optical obstructions, including potential obstructions that may move
due to wind, human activity, growth of vegetation, etc. Temporary
optical obstructions, such as rain, particles, fog, or snow, should
be considered when siting an open path analyzer. Any of these
temporary obstructions that are of sufficient density to obscure the
light beam will affect the ability of the open path analyzer to
continuously measure pollutant concentrations. Transient, but
significant obscuration of especially longer measurement paths could
occur as a result of certain meteorological conditions (e.g., heavy
fog, rain, snow) and/or aerosol levels that are of a sufficient
density to prevent the open path analyzer's light transmission. If
certain compensating measures are not otherwise implemented at the
onset of monitoring (e.g., shorter path lengths, higher light source
intensity), data recovery during periods of greatest primary
pollutant potential could be compromised. For instance, if heavy fog
or high particulate levels are coincident with periods of projected
NAAQS-threatening pollutant potential, the representativeness of the
resulting data record in reflecting maximum pollutant concentrations
may be substantially impaired despite the fact that the site may
otherwise exhibit an acceptable, even exceedingly high overall valid
data capture rate.
5. Spacing From Trees
(a) Trees can provide surfaces for SO2,
O3, or NO2 adsorption or reactions, and
surfaces for particle deposition. Trees can also act as obstructions
in cases where they are located between the air pollutant sources or
source areas and the monitoring site, and where the trees are of a
sufficient height and leaf canopy density to interfere with the
normal airflow around the probe, inlet, or monitoring path. To
reduce this possible interference/obstruction, the probe, inlet, or
at least 90 percent of the monitoring path must be at least 10
meters or further from the drip line of trees.
(b) The scavenging effect of trees is greater for O3
than for other criteria pollutants. Monitoring agencies must take
steps to consider the impact of trees on ozone monitoring sites and
take steps to avoid this problem.
(c) For microscale sites of any air pollutant, no trees or
shrubs should be located between the probe and the source under
investigation, such as a roadway or a stationary source.
6. Spacing From Roadways
6.1 Spacing for Ozone and Oxide of Nitrogen Probes and
Monitoring Paths. In siting an O3 analyzer, it is
important to minimize destructive interferences from sources of NO,
since NO readily reacts with O3. In siting NO2
analyzers for neighborhood and urban scale monitoring, it is
important to minimize interferences from automotive sources. Table
E-1 of this appendix provides the required minimum separation
distances between a roadway and a probe or, where applicable, at
least 90 percent of a monitoring path for various ranges of daily
roadway traffic. A sampling site having a point analyzer probe
located closer to a roadway than allowed by the Table E-1
requirements should be classified as middle scale rather than
neighborhood or urban scale, since the measurements from such a site
would more closely represent the middle scale. If an open path
analyzer is used at a site, the monitoring path(s) must not cross
over a roadway with an average daily traffic count of 10,000
vehicles per day or more. For those situations where a monitoring
path crosses a roadway with fewer than 10,000 vehicles per day, one
must consider the entire segment of the monitoring path in the area
of potential atmospheric interference from automobile emissions.
Therefore, this calculation must include the length of the
monitoring path over the roadway plus any segments of the
[[Page 61325]]
monitoring path that lie in the area between the roadway and the
minimum separation distance, as determined from Table E-1 of this
appendix. The sum of these distances must not be greater than 10
percent of the total monitoring path length.
Table E-1 to Appendix E of Part 58. Minimum Separation Distance Between
Roadways and Probes or Monitoring Paths for Monitoring Neighborhood and
Urban Scale Ozone (O3) and Oxides of Nitrogen (NO, NO2, NOX, NOy)
------------------------------------------------------------------------
Minimum Minimum
Roadway average daily traffic, vehicles distance \1\ distance 1, 2
per day (meters) (meters)
------------------------------------------------------------------------
<=1,000................................. 10 10
10,000.................................. 10 20
15,000.................................. 20 30
20,000.................................. 30 40
40,000.................................. 50 60
70,000.................................. 100 100
>=110,000............................... 250 250
------------------------------------------------------------------------
\1\ Distance from the edge of the nearest traffic lane. The distance for
intermediate traffic counts should be interpolated from the table
values based on the actual traffic count.
\2\ Applicable for ozone monitors whose placement has not already been
approved as of December 18, 2006.
6.2 Spacing for Carbon Monoxide Probes and Monitoring Paths. (a)
Street canyon and traffic corridor sites (microscale) are intended
to provide a measurement of the influence of the immediate source on
the pollution exposure of the population. In order to provide some
reasonable consistency and comparability in the air quality data
from microscale sites, a minimum distance of 2 meters and a maximum
distance of 10 meters from the edge of the nearest traffic lane must
be maintained for these CO monitoring inlet probes. This should give
consistency to the data, yet still allow flexibility of finding
suitable locations.
(b) Street canyon/corridor (microscale) inlet probes must be
located at least 10 meters from an intersection and preferably at a
midblock location. Midblock locations are preferable to intersection
locations because intersections represent a much smaller portion of
downtown space than do the streets between them. Pedestrian exposure
is probably also greater in street canyon/corridors than at
intersections.
(c) In determining the minimum separation between a neighborhood
scale monitoring site and a specific roadway, the presumption is
made that measurements should not be substantially influenced by any
one roadway. Computations were made to determine the separation
distance, and Table E-2 of this appendix provides the required
minimum separation distance between roadways and a probe or 90
percent of a monitoring path. Probes or monitoring paths that are
located closer to roads than this criterion allows should not be
classified as a neighborhood scale, since the measurements from such
a site would closely represent the middle scale. Therefore, sites
not meeting this criterion should be classified as middle scale.
Table E-2 to Appendix E of Part 58. Minimum Separation Distance Between
Roadways and Probes or Monitoring Paths for Monitoring Neighborhood
Scale Carbon Monoxide
------------------------------------------------------------------------
Minimum
Roadway average daily traffic, vehicles per day distance \1\
(meters)
------------------------------------------------------------------------
<=10,000................................................ 10
15,000.................................................. 25
20,000.................................................. 45
30,000.................................................. 80
40,000.................................................. 115
50,000.................................................. 135
>=60,000................................................ 150
------------------------------------------------------------------------
\1\ Distance from the edge of the nearest traffic lane. The distance for
intermediate traffic counts should be interpolated from the table
values based on the actual traffic count.
6.3 Spacing for Particulate Matter (PM2.5,
PM10, Pb) Inlets. (a) Since emissions associated with the
operation of motor vehicles contribute to urban area particulate
matter ambient levels, spacing from roadway criteria are necessary
for ensuring national consistency in PM sampler siting.
(b) The intent is to locate localized hot-spot sites in areas of
highest concentrations whether it be from mobile or multiple
stationary sources. If the area is primarily affected by mobile
sources and the maximum concentration area(s) is judged to be a
traffic corridor or street canyon location, then the monitors should
be located near roadways with the highest traffic volume and at
separation distances most likely to produce the highest
concentrations. For the microscale traffic corridor site, the
location must be between 5 and 15 meters from the major roadway. For
the microscale street canyon site the location must be between 2 and
10 meters from the roadway. For the middle scale site, a range of
acceptable distances from the roadway is shown in figure E-1 of this
appendix. This figure also includes separation distances between a
roadway and neighborhood or larger scale sites by default. Any site,
2 to 15 meters high, and further back than the middle scale
requirements will generally be neighborhood, urban or regional
scale. For example, according to Figure E-1 of this appendix, if a
PM sampler is primarily influenced by roadway emissions and that
sampler is set back 10 meters from a 30,000 ADT (average daily
traffic) road, the site should be classified as microscale, if the
sampler height is between 2 and 7 meters. If the sampler height is
between 7 and 15 meters, the site should be classified as middle
scale. If the sample is 20 meters from the same road, it will be
classified as middle scale; if 40 meters, neighborhood scale; and if
110 meters, an urban scale.
[[Page 61326]]
[GRAPHIC] [TIFF OMITTED] TR17OC06.061
7. Cumulative Interferences on a Monitoring Path
(This paragraph applies only to open path analyzers.) The
cumulative length or portion of a monitoring path that is affected
by minor sources, trees, or roadways must not exceed 10 percent of
the total monitoring path length.
8. Maximum Monitoring Path Length
(This paragraph applies only to open path analyzers.) The
monitoring path length must not exceed 1 kilometer for analyzers in
neighborhood, urban, or regional scale. For middle scale monitoring
sites, the monitoring path length must not exceed 300 meters. In
areas subject to frequent periods of dust, fog, rain, or snow,
consideration should be given to a shortened monitoring path length
to minimize loss of monitoring data due to these temporary optical
obstructions. For certain ambient air monitoring scenarios using
open path analyzers, shorter path lengths may be needed in order to
ensure that the monitoring site meets the objectives and spatial
scales defined in appendix D to this part. The Regional
Administrator may require shorter path lengths, as needed on an
individual basis, to ensure that the SLAMS sites meet the appendix D
requirements. Likewise, the Administrator may specify the maximum
path length used at NCore monitoring sites.
9. Probe Material and Pollutant Sample Residence Time
(a) For the reactive gases, SO2, NO2, and
O3, special probe material must be used for point
analyzers. Studies 20-24 have been conducted to determine
the suitability of materials such as polypropylene, polyethylene,
polyvinyl chloride, Tygon[supreg], aluminum, brass, stainless steel,
copper, Pyrex[supreg] glass and Teflon[supreg] for use as intake
sampling lines. Of the above materials, only Pyrex[supreg] glass and
Teflon[supreg] have been found to be acceptable for use as intake
sampling lines for all the reactive gaseous pollutants. Furthermore,
the EPA25 has specified borosilicate glass or FEP
Teflon[supreg] as the only acceptable probe materials for delivering
test atmospheres in the determination of reference or equivalent
methods. Therefore, borosilicate glass, FEP Teflon[supreg] or their
equivalent must be the only material in the sampling train (from
inlet probe to the back of the analyzer) that can be in contact with
the ambient air sample for existing and new SLAMs.
(b) For volatile organic compound (VOC) monitoring at PAMS, FEP
Teflon[supreg] is unacceptable as the probe material because of VOC
adsorption and desorption reactions on the FEP Teflon[supreg].
Borosilicate glass, stainless steel, or its equivalent are the
acceptable probe materials for VOC and carbonyl sampling. Care must
be taken to ensure that the sample residence time is kept to 20
seconds or less.
(c) No matter how nonreactive the sampling probe material is
initially, after a period of use reactive particulate matter is
deposited on the probe walls. Therefore, the time it takes the gas
to transfer from the probe inlet to the sampling device is also
critical. Ozone in the presence of nitrogen oxide (NO) will show
significant losses even in the most inert probe material when the
residence time exceeds 20 seconds.26 Other studies
27-28 indicate that a 10-second or less residence time is
easily achievable. Therefore, sampling probes for reactive gas
monitors at NCore must have a sample residence time less than 20
seconds.
10. Waiver Provisions
Most sampling probes or monitors can be located so that they
meet the requirements of this appendix. New sites with rare
exceptions, can be located within the limits of this appendix.
However, some existing sites may not meet these requirements and
still produce useful data for some purposes. The EPA will consider a
written request from the State agency to waive one or more siting
criteria for some monitoring sites providing that the State can
adequately demonstrate the need (purpose) for monitoring or
establishing a monitoring site at that location.
10.1 For establishing a new site, a waiver may be granted only
if both of the following criteria are met:
10.1.1 The site can be demonstrated to be as representative of
the monitoring area as it would be if the siting criteria were being
met.
10.1.2 The monitor or probe cannot reasonably be located so as
to meet the siting criteria because of physical constraints (e.g.,
inability to locate the required type of site the necessary distance
from roadways or obstructions).
10.2 However, for an existing site, a waiver may be granted if
either of the criteria in sections 10.1.1 and 10.1.2 of this
appendix are met.
10.3 Cost benefits, historical trends, and other factors may be
used to add support to the criteria in sections 10.1.1 and 10.1.2 of
this appendix, however, they in themselves, will not be acceptable
reasons for granting a waiver. Written requests for waivers must be
submitted to the Regional Administrator.
11. Summary
Table E-4 of this appendix presents a summary of the general
requirements for probe and monitoring path siting criteria with
respect to distances and heights. It is apparent from Table E-4 that
different elevation distances above the ground are shown for the
various pollutants. The discussion in this appendix for each of the
pollutants describes reasons for elevating the monitor, probe, or
monitoring path. The differences in the specified range of heights
[[Page 61327]]
are based on the vertical concentration gradients. For CO, the
gradients in the vertical direction are very large for the
microscale, so a small range of heights are used. The upper limit of
15 meters is specified for consistency between pollutants and to
allow the use of a single manifold or monitoring path for monitoring
more than one pollutant.
Table E-4 of Appendix E to Part 58. Summary of Probe and Monitoring Path Siting Criteria
--------------------------------------------------------------------------------------------------------------------------------------------------------
Horizontal and
vertical distance
Scale (maximum Height from ground from supporting Distance from trees Distance from
Pollutant monitoring path to probe, inlet or structures \2\ to to probe, inlet or roadways to probe,
length, meters) 80% of monitoring probe, inlet or 90% 90% of monitoring inlet or monitoring
path \1\ of monitoring path path \1\ (meters) path \1\ (meters)
\1\ (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2 3,4,5,6............................. Middle (300 m) 2-15................ > 1................. > 10................ N/A
Neighborhood Urban,
and Regional (1 km).
CO 4,5,7................................ Micro, middle (300 3\1/2\: > 1................. > 10................ 2-10; see Table E-2
m), Neighborhood (1 2-15. of this appendix for
km). middle and
neighborhood scales.
NO2, O3 3,4,5........................... Middle (300 m) 2-15................ > 1................. > 10................ See Table E-1 of this
Neighborhood, Urban, appendix for all
and Regional (1 km). scales.
Ozone precursors (for PAMS) 3,4,5....... Neighborhood and 2-15................ > 1................. > 10................ See Table E-4 of this
Urban (1 km). appendix for all
scales.
PM,Pb 3,4,5,6,8......................... Micro: Middle, 2-7 (micro); 2-7 > 2 (all scales, > 10 (all scales)... 2-10 (micro); see
Neighborhood, Urban (middle PM10 2.5); horizontal distance Figure E-1 of this
and Regional. 2-15 (all other only). appendix for all
scales). other scales.
--------------------------------------------------------------------------------------------------------------------------------------------------------
N/A--Not applicable.
\1\ Monitoring path for open path analyzers is applicable only to middle or neighborhood scale CO monitoring and all applicable scales for monitoring
SO2,O3, O3 precursors, and NO2.
\2\ When probe is located on a rooftop, this separation distance is in reference to walls, parapets, or penthouses located on roof.
\3\ Should be >20 meters from the dripline of tree(s) and must be 10 meters from the dripline when the tree(s) act as an obstruction.
\4\ Distance from sampler, probe, or 90% of monitoring path to obstacle, such as a building, must be at least twice the height the obstacle protrudes
above the sampler, probe, or monitoring path. Sites not meeting this criterion may be classified as middle scale (see text).
\5\ Must have unrestricted airflow 270 degrees around the probe or sampler; 180 degrees if the probe is on the side of a building.
\6\ The probe, sampler, or monitoring path should be away from minor sources, such as furnace or incineration flues. The separation distance is
dependent on the height of the minor source's emission point (such as a flue), the type of fuel or waste burned, and the quality of the fuel (sulfur,
ash, or lead content). This criterion is designed to avoid undue influences from minor sources.
\7\ For microscale CO monitoring sites, the probe must be >10 meters from a street intersection and preferably at a midblock location.
\8\ Collocated monitors must be within 4 meters of each other and at least 2 meters apart for flow rates greater than 200 liters/min or at least 1 meter
apart for samplers having flow rates less than 200 liters/min to preclude airflow interference.
12. References
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[[Page 61328]]
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27711. EPA 450/4-87-013. June 1987F.
Appendix F--[Removed and Reserved]
38. Appendix F to part 58 is removed and reserved.
[FR Doc. 06-8478 Filed 10-16-06; 8:45 am]
BILLING CODE 6560-50-P