Order Code RL32431
Particulate Matter (PM ): Implementation of the
2.5
1997 National Ambient Air Quality Standards
(NAAQS)
Updated November 26, 2008
Robert Esworthy
Specialist in Environmental Policy
Resources, Science, and Industry Division

Particulate Matter (PM ): Implementation of the
2.5
1997 National Ambient Air Quality Standards (NAAQS)
Summary
Particulate matter (PM), including fine particulate matter (PM ) and larger, but
2.5
still inhalable particles (PM ), is one of the six principal pollutants for which the
10
U.S. Environmental Protection Agency (EPA) has set National Ambient Air Quality
Standards (NAAQS) under the Clean Air Act (CAA). Primary NAAQS are designed
to protect human health, with an adequate margin of safety. After years of litigation
and other delays, EPA is implementing the NAAQS for PM promulgated in 1997.
2.5
This report outlines the implementation process for the 1997 PM NAAQS and
2.5
describes issues raised as EPA and states develop implementation strategies.
The EPA’s final designation of 38 areas, consisting of 205 counties in 20 states
and the District of Columbia, as “nonattainment” (out of compliance) areas for the
1997 PM NAAQS became effective in April 2005. A combined population of
2.5
almost 90 million resides in these areas. States with PM nonattainment areas are
2.5
required to develop comprehensive implementation plans, referred to as State
Implementation Plans (SIPs), demonstrating how attainment will be reached by a
designated deadline. SIPs include pollution control measures that rely on models of
the impact on air quality of projected emission reductions to demonstrate attainment.
States were required to submit SIPs for the 1997 PM NAAQS by April 2008, but
2.5
EPA did not begin receiving most of them until July 2008. States must be in
compliance by 2010, unless they are granted an extension.
A number of issues will continue to be debated as the implementation of the
1997 PM NAAQS progresses. The U.S. Court of Appeals for the D.C. Circuit’s
2.5
July 11, 2008, decision (North Carolina v. EPA) to vacate the Clean Air Interstate
Rule (CAIR) could further delay implementation, which has heightened interest in
Congress. CAIR was expected to assist states in addressing upwind emission
contributions for achieving attainment of the 1997 PM NAAQS. In addition, other
2.5
EPA rulemakings promulgated and proposed that influence various aspects of
regulating air quality could affect the PM NAAQS implementation process. EPA’s
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April 25, 2007, final “PM implementation” rule to provide guidance and
2.5
procedures for establishing controls to achieve and maintain attainment has raised
concerns. Six petitions for review of the rule were filed with the D.C. Circuit, and
two petitions for reconsideration have been filed with EPA. Additionally, as required
under the CAA, EPA reviewed the PM and PM NAAQS, and on October 17,
2.5
10
2006, promulgated final revisions that included a strengthening of the 1997 PM2.5
standard. Pending judicial actions regarding the 2006 PM NAAQS could affect
implementation of the 1997 PM NAAQS.
2.5
As implementation of the 1997 NAAQS moves forward, its effects on states and
tribes will be a continued issue of interest to Congress. Many questions and concerns
remain, including whether special provisions can be made for meeting attainment
deadlines, particularly for areas affected by upwind pollution, and how nonattainment
designation might affect economic development.

Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The 1997 PM Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.5
Overview: Key Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Compliance Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Timeliness of Implementation Guidance . . . . . . . . . . . . . . . . . . . . . . . . 3
The Clean Air Interstate Rule (CAIR) and
Other Federal Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
EPA’s 2006 Revisions to the PM NAAQS . . . . . . . . . . . . . . . . . . . . . . 5
Geographical Area Designation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The NAAQS Designation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1997 PM NAAQS Designation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.5
1997 PM Area Designations Timeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.5
Demonstrating Attainment with the 1997 PM NAAQS . . . . . . . . . . . . . . . . . . 12
2.5
The State Implementation Plan (SIP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
EPA’s PM Implementation Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5
Transportation Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Upwind Pollutant Contributions: § 126 of the CAA . . . . . . . . . . . . . . . . . . 15
Grant Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Recent Actions and Their Implications for Achieving Attainment
of the 1997 PM NAAQS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.5
D.C. Circuit’s Decision Vacating the Clean Air Interstate Rule
(CAIR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Completion of EPA’s Review of the Particulates NAAQS
and the September 2006 Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Congressional Action Related to Particulates NAAQS Implementation . . . . . . . 22
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Appendix. Implementation of the 1997 PM NAAQS:
2.5
Timeline and Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
List of Figures
Figure 1. EPA Designations of Nonattainment Areas for the 1997 PM
2.5
National Ambient Air Quality Standards (NAAQS) . . . . . . . . . . . . . . . . . . 11
List of Tables
Table 1. Areas Previously Identified as Nonattainment for 1997 PM
2.5
NAAQS Designated as Attaining the Standards . . . . . . . . . . . . . . . . . . . . . 10
Table 2. Schedule for Implementation of the 1997 PM NAAQS . . . . . . . . . . 26
2.5

Particulate Matter (PM ): Implementation of
2.5
the 1997 National Ambient Air Quality
Standards (NAAQS)
Introduction
National Ambient Air Quality Standards (NAAQS) are a core component of the
Clean Air Act (CAA).1 NAAQS do not regulate emission sources directly; rather,
they define the level of pollution in ambient (outdoor) air above which health and
welfare effects occur. The statute requires that, based on a review of the scientific
literature, the Environmental Protection Agency (EPA) set (1) “primary” standards
at a level “requisite to protect the public health” with an “adequate margin of safety”
and (2) “secondary” standards at a level “requisite to protect the public welfare.”2
NAAQS have been promulgated for six principal pollutants classified by EPA as
“criteria pollutants”: sulfur oxides measured in terms of sulfur dioxide (SO ),
2
nitrogen dioxide (NO ), carbon monoxide (CO), ozone, lead, and particulate matter.
2
This report provides an overview of the NAAQS implementation process in the
context of the 1997 standards for fine particulate matter (PM ), which consists of
2.5
particles less than 2.5 micrometers in diameter. The EPA is in the process of
implementing the NAAQS for particulates promulgated in 1997,3 delayed because
of court challenges and other factors. The EPA’s 1997 revisions to the particulate
matter standards (also referred to as the particulates NAAQS) included separate
requirements for PM for the first time. The PM NAAQS have been the source
2.5
2.5
of significant concern and national debate. Congress has been particularly interested
in EPA’s promulgation and implementation of the CAA standards, and has held
numerous hearings on particulate matter (and ozone) NAAQS established in 1997.
1 Sections 108 and 109 of the CAA govern the establishment, review, and revisions of
NAAQS (42 U.S.C. 7408 and 7409). See CRS Report 97-722, Air Quality Standards: The
Decisionmaking Process
, by John Blodgett and Larry Parker.
2 42 U.S.C. 7409(b)(1) for “primary”; 42 U.S.C. 7409(b)(2) and 7602(h) for “secondary.”
The use of public welfare in the CAA “includes, but is not limited to, effects on soils, water,
crops, vegetation, manmade materials, animals, wildlife, weather, visibility, and climate,
damage to and deterioration of property, and hazards to transportation, as well as effects on
economic values and on personal comfort and well-being, whether caused by transformation,
conversion, or combination with other air pollutants” (42 U.S.C. 7602(h)).
3 62 Federal Register 38652-38760, July 18, 1997.

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The 1997 PM Standards
2.5
Beginning in 1971, regulation and monitoring of particulate matter under the
CAA focused primarily on total suspended particles (TSP) and, eventually, on coarse
particles equal to or less than 10 micrometers in diameter (PM ).4 After extensive
10
analysis and review, EPA revised the particulates standards in 19975 to provide
separate requirements for fine particulate matter (PM ) based on its links to several
2.5
types of cardiovascular and respiratory health problems, including aggravated asthma
and bronchitis, and to premature death.6
The primary (health) PM NAAQS requirements, which became effective on
2.5
September 16, 1997,7 are the same as the secondary (welfare) requirements. The 1997
PM standards are set at
2.5
! an annual maximum concentration of 15 micrograms per cubic
meter (µg/m3), based on the three-year average of the annual
arithmetic mean PM concentrations from one or more community-
2.5
oriented monitors,8 and
! a 24-hour concentration of 65 µ g/m3, based on the three-year average
of the 98th percentile of 24-hour PM concentrations at each
2.5
population-oriented monitor9 within an area.
Overview: Key Issues
A key component of implementing the 1997 PM NAAQS is EPA’s
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designations of geographical areas for being in “attainment” (in compliance) or
“nonattainment” (out of compliance) of the air quality standards for PM . As of
2.5
August 2008, EPA’s final designations included all or part of 205 counties10 in 20
4 52 Federal Register 24634-24715, July 1, 1987.
5 62 Federal Register 38652-38760, July 18, 1997. See also U.S. EPA Fact Sheet, EPA’s
Revised Particulate Matter Standards
, July 17, 1997, [http://www.epa.gov/ttn/oarpg/
naaqsfin/pmfact.html].
6 For an update of EPA’s health effects and other particulates-related research activities, see
[http://www.epa.gov/pmresearch/].
7 62 Federal Register 38652-38760, July 18, 1997.
8 Community-oriented monitoring zones are defined as “an optional averaging area with well
established boundaries such as county or census block” (40 CFR Part 58 Subpart A).
9 Population-oriented monitoring (or sites) applies to “residential areas, commercial areas,
recreational areas, industrial areas, and other areas where a substantial number of people
may spend a significant fraction of their day” (40 CFR Part 58 Subpart A).
10 All designated counties and partial counties, including Indian Country, geographically
located within such areas, except as otherwise indicated by EPA. See EPA’s PM2.5
Designations website at [http://www.epa.gov/pmdesignations].

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states and the District of Columbia for nonattainment of the 1997 PM NAAQS.11
2.5
A combined population of almost 90 million resides in these nonattainment areas.
The final designations were based on EPA’s consideration of air monitoring data and
recommendations provided by states and tribes. The designation of nonattainment
areas raised questions and concerns, particularly for those areas designated as such
for the first time.
Compliance Schedule. Nonattainment designation began a process in which
states (and tribes) must develop and adopt emission control programs sufficient to
bring air quality into compliance by a statutorily defined deadline. States were
required to submit, by April 2008, their State Implementation Plans (SIPs) for how
the designated nonattainment areas will meet the 1997 PM NAAQS. According
2.5
to EPA, nine of the 57 SIPs (there are 38 areas, but some have multiple states
submitting individual SIPs) had been submitted as of the end of August 2008.12
States with nonattainment areas must be in compliance with the 1997 PM NAAQS
2.5
by April 5, 2010, unless they are granted an extension.13
Timeliness of Implementation Guidance. Concerns were raised
regarding compliance deadlines with respect to EPA’s timely provision of
implementation procedures and guidance for achieving and maintaining compliance
with the 1997 PM NAAQS. The EPA published its final “PM implementation”
2.5
2.5
rule on April 25, 2007.14 Six petitions for review of EPA’s implementation rule
have been filed with the U.S. Court of Appeals for the District of Columbia (D.C.)
Circuit,15 and two petitions for reconsideration have been filed with EPA.16 Given
11 The EPA published a final supplemental rule on April 14, 2005 (70 Federal Register
19844) amending the agency’s initial final designations published in the January 5, 2005,
70 Federal Register 944-1019, re-designating as attainment/unclassifiable 17 counties
previously designated nonattainment. Subsequently, in the August 25, 2008, 73 Federal
Register
49949, EPA announced its determination that a three-county (Harrisburg, Lebanon,
Carlisle) Pennsylvania nonattainment area for the 1997 PM NAAQS, had achieved
2.5
attainment.
12 Information provided directly to CRS by the EPA Office of Air Quality Planning and
Standards (OAQPS) based on consultation with the EPA Regions.
13 Under section 172(a)(2)(A) of the CAA, EPA may grant an area an extension of the initial
attainment date for one to five years (in no case later than 10 years after the designation date
for the area). A state requesting an extension must submit an implementation plan (SIP) by
the required deadline that includes, among other things, sufficient information
demonstrating that attainment by the initial attainment date is “impracticable.”
14 72 Federal Register 20586 — 20667, April 25, 2007.
15 The six petitions are: Earthjustice on behalf of American Lung Association, National
Resources Defense Council, Sierra Club and Medical Advocates for Healthy Air (American
Lung Association v. EPA, No. 07-1233, D.C. Cir. filed June 26, 2007); National
Environmental Development Association’s Clean Air Project (NEDA CAP); National
Petrochemical & Refiners Association; State of New York; State of New Jersey; National
Cattlemen’s Beef Association.
16 Earthjustice, Petition for Reconsideration, Final Clean Air Fine Particle Implementation,
filed before the Administrator of the U.S. Environmental Protection Agency, June 25, 2007,
(continued...)

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that states were required to submit their SIPs by April 2008, state and local air
pollution control agencies,17 as well as some Members of Congress,18 had expressed
their concerns about the delays in publishing a final implementation rule19 and the
lack of guidance.
The Clean Air Interstate Rule (CAIR) and Other Federal
Requirements. The EPA concluded that in many cases implementing national
strategies — including the 1999 visibility protection regulations (Regional Haze
Rule);20 voluntary diesel engine retrofit programs; and federal standards scheduled
to be implemented between 2004 and 2010 on cars, light trucks, heavy-duty, and
nonroad diesel engines — would provide a framework for achieving attainment with
the 1997 PM NAAQS. The EPA’s May 2005 final rule, the Clean Air Interstate
2.5
Rule (CAIR),21 was expected to serve as the primary tool to assist downwind states
in meeting the PM (and 8-hour ozone) NAAQS by mitigating interstate transport
2.5
of sulfur dioxide (SO ) and nitrogen oxide (NOx) emissions from electric generating
2
units that contribute to the formation of PM .22 CAIR covered 28 states in the
2.5
eastern United States and the District of Columbia, including 26 jurisdictions in the
PM nonattainment region. As a preferred implementation strategy, EPA encouraged
2.5
states to use a trading program to reduce emissions of target pollutants by up to 70%
16 (...continued)
(Docket #EPA-HQ-OAR-2003-0062-0256 available at [http://www.regulations.gov/search/
index.jsp]); and petition by the National Cattlemen’s Beef Association (based on
information received by CRS from EPA’s Office of Air Quality Planning and Standards,
March 19, 2008).
17 Letter of Shelley Kaderly and Ursula Kramu, Co-Presidents, the National Association of
Clean Air Agencies (NACAA, formerly the State and Territorial Air Pollution Program
Administrators and the Association of Local Air Pollution Control Officials
(STAPPA/ALAPCO)), to Hon. Stephen L. Johnson, EPA Administrator, February 16, 2007,
available at [http://www.4cleanair.org/TopicDetails.asp?parent=2#Particle%20Pollution].
18 Letter of the Hon. John D. Dingell, Chairman of the House Committee on Energy and
Commerce, to Hon. Stephen L. Johnson, EPA Administrator, January 19, 2007,
[http://energycommerce.house.gov/Press_110/110pr_air_quality.shtml].
19 The EPA had published a proposed rule November 1, 2005 (70 Federal Register 65984).
20 64 Federal Register 35714-35774, July 1, 1999. See CRS Report RL32483 Visibility,
Regional Haze, and the Clean Air Act: Status of Implementation
by Larry Parker and John
Blodgett; also CRS Report RL32927, Clean Air Interstate Rule: Review and Analysis, by
Larry Parker.
21 Promulgated under the CAA, 42 U.S.C. 7401 et seq., 70 Federal Register 25162, May 12,
2005.
22 Sulfur dioxide (SO ) is a precursor contributing to the formation of PM concentrations,
2
2.5
and NOx is a precursor (a pollutant that is transformed in air to form another air pollutant)
contributing to the formation of both ozone and PM concentrations. EPA has concluded
2.5
that SO and NOx emissions, through the phenomenon of air pollution transport, contribute
2
significantly to downwind nonattainment, or interfere with maintenance, of the PM and
2.5
8-hour ozone NAAQS (70 Federal Register 25162, May 12, 2005).

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in a cost-effective manner.23 However, in a July 11, 2008, decision (North Carolina
v. EPA
), the U.S. Court of Appeals for the D.C. Circuit vacated CAIR.24 The court
decision may require states to reconsider implementation plans (SIPs) already
submitted and those pending submission for achieving or maintaining attainment
with 1997 PM NAAQS.25 The court’s decision to vacate the rule was the subject
2.5
of a July 29, 2008, congressional hearing,26 and the implications of this decision are
expected to be the topic of further deliberation by Congress. In September 2008,
EPA and other petitioners requested a rehearing of the D.C. Circuit’s decision, and
in November 2008 EPA requested a two-year stay of the decision.27
EPA’s 2006 Revisions to the PM NAAQS. Further complicating issues
associated with achieving attainment of 1997 PM NAAQS, EPA promulgated
2.5
revisions to the NAAQS for particulate matter on October 17, 2006,28 primarily a
tightening of the 1997 standard for PM .29 The tightening of the PM standards30
2.5
2.5
increases the number of areas (defined by counties or portions of counties) in
nonattainment.
EPA notified state and tribal representatives of the agency’s intended
designations of areas for nonattatinment of the 2006 PM NAAQS in letters dated
2.5
August 19, 2008.31 In response to nonattainment recommendations (based on 2004-
2006 monitoring data) provided by states and tribes in December 2007, EPA
identified 169 counties, and portions of 46 additional counties, for designation as
nonattainment. States (and tribal groups) have 120 days to respond to EPA’s
recommendations. EPA expects to finalize the 2006 PM NAAQS nonattainment
2.5
designations (based on 2005-2007 monitoring data) by the end of 2008, with an
23 See EPA’s CAIR website at [http://www.epa.gov/airmarkets/progsregs/cair/index.html].
24 531 F.3d 896 (D.C. Cir. 2008).
25 For a more detailed discussion of the court’s decision and its implications, see CRS
Report RL34589, Clean Air After the CAIR Decision: Back to Square One?, by James E.
McCarthy, Larry Parker, and Robert Meltz.
26 Senate Committee on Environment and Public Works, Subcommittee on Clean Air and
Nuclear Safety, hearing, “EPA’s Clean Air Interstate Rule (CAIR): Recent Court Decision
and its Implications,” July 29, 2008 [http://epw.senate.gov/public/].
27 In addition to EPA, the Natural Resources Defense Council (NRDC), the National Mining
Association, and the Utility Air Regulatory Group requested a rehearing.
28 71 Federal Register 61143-61233, October 17, 2006. See CRS Report RL33254, Air
Quality: EPA’s 2006 Changes to the Particulate Matter (PM) Standard
, by Robert Esworthy
and James E. McCarthy.
29 Section 109(d)(1) of the CAA. According to the statute, EPA is required to review the
latest scientific studies and either reaffirm or modify the NAAQS every five years, but
reviews have occurred less frequently in practice.
30 The new daily standard averaged over 24-hour periods is reduced from 65 micrograms per
cubic meter (µg/m3) to 35 µg/m3 (71 Federal Register 61143-61233, October 17, 2006).
31 For information regarding EPA’s proposed designations, including correspondence
between EPA and state and tribal representatives, see [http://www.epa.gov/pmdesignations/
2006standards/regs.htm#2].

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effective date of April 2009. SIPs would be due three years later, in April of 2012.32
States are required to meet the 2006 revised PM NAAQS no later than five years
2.5
from the date of designation — April 2014 — unless granted an extension.33 The
EPA urged states to consider control strategies that may be useful in attaining the
2006 revised PM NAAQS when developing control strategies for the 1997 PM
2.5
2.5
standards.34 Further delays in implementing the 1997 NAAQS as a result of the
court’s decision regarding CAIR could result in some stakeholders advocating
moving directly to implementation of the 2006 standards.
Geographical Area Designation Process
The NAAQS Designation Process35
The designation of geographical areas failing to comply with the NAAQS, based
on monitoring and analysis of relevant air quality data, is a critical step in NAAQS
implementation. The CAA establishes a process for designating nonattainment areas
and setting their boundaries, but it allows the EPA Administrator some discretion in
determining what the final boundaries of the areas will be. Areas are identified as
“nonattainment” when they violate or contribute to the violation of NAAQS. Areas
are identified as “attainment/unclassified”36 when they meet the standard or when the
data are insufficient for determining compliance with the NAAQS.37
32 See EPA’s guidance on its website: “Area Designations for 2006 24-Hour PM2.5 NAAQS
— Technical Information,” [http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html].
33 Under section 172(a)(2)(A) of the CAA, EPA may grant an area an extension of the initial
attainment date for one to five years (in no case later than 10 years after the designation date
for the area) if a state demonstrates that severe air quality conditions prevent achieving
attainment within the five years after designation. A state requesting an extension must
submit an implementation plan (SIP) by the required deadline that includes, among other
things, sufficient information demonstrating that attainment by the initial attainment date
is “impracticable.”
34 EPA’s Advanced Notice of Proposed Rulemaking outlining an implementation plan for
the transition to the January 17, 2006, proposed particulates NAAQS (71 Federal Register
6722, February 9, 2006).
35 The EPA reported that 120 areas were designated as nonattainment for at least one of the
six criteria pollutants (including particulate matter) as of August 2008 (EPA’s Criteria
Pollutant Area Summary Report
(as of August 15, 2008; the data are periodically updated)
at [http://www.epa.gov/oar/oaqps/greenbk/ancl2.html]).
36 Section 107(d)(1)(A)(iii) of the CAA provides that any area that EPA cannot designate
on the basis of available information as meeting or not meeting the standards should be
designated unclassifiable.
37 The EPA “Greenbook” lists areas of the country where air pollution levels persistently
exceed the national ambient air quality standards and may be designated as nonattainment.
Current information on the location of NAAQS nonattainment areas is available on EPA’s
website at [http://www.epa.gov/oar/oaqps/greenbk/].

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The designation process is intended as a cooperative federal-state-tribal38
process in which states and tribes provide initial designation recommendations to
EPA for consideration. In Section 107(d)(1)(A) (42 U.S.C. 7407), the statute states
that the governor of each state shall submit a list to EPA of all areas in the state,
“designating as ... nonattainment, any area that does not meet (or that contributes
to ambient air quality in a nearby area that does not meet
) an air quality standard”
(emphasis added).
Following state and tribal designation submissions, the EPA Administrator has
discretion to make modifications, including to the area boundaries. As required by
statute (Section 107[d]1[B][ii]), the agency must notify the states and tribes regarding
any modifications, allowing them sufficient opportunity to demonstrate why a
proposed modification is inappropriate, but the final determination rests with EPA.
1997 PM NAAQS Designation Process
2.5
PM attainment or nonattainment designations were made primarily on the
2.5
basis of three-year federally referenced PM monitoring data.39 At the time the
2.5
PM NAAQS were being finalized in 1997, EPA began developing methods for
2.5
monitoring fine particles. Using funding specifically authorized for this purpose in
FY1998-FY2000 EPA appropriations,40 the agency worked closely with states and
tribes to initiate the deployment of a portion of the network of 1,200 monitors in
January 1999. The majority of the monitors were not in place until January 2000.
States and tribes were expected to rely on data collected during 2000-2002 for their
recommendations. The EPA considered the 2001-2003 data to make the final PM2.5
designations published in January 2005.
In its guidance document,41 EPA identified several factors that would be
considered in determining attainment with the 1997 PM NAAQS and specified data
2.5
and conditions that would not be acceptable. The EPA’s nonbinding guidance also
included a recommendation that states and tribes consider using the same boundaries
for nonattainment for both the PM and eight-hour ozone standards, to facilitate
2.5
38 Though not required to do so, tribes have been encouraged to submit recommendations.
The area designation requirements under the CAA (Section 107) are specific with respect
to states, but not to tribes. The EPA follows the same designation process for tribes per
Sections 110(o) and 301(d) of the CAA and pursuant to the 1988 Tribal Authority Rule,
which specifies that tribes shall be treated as states in selected cases (40 CFR Part 49). For
information regarding tribes that have participated in the PM designation recommendation
2.5
process, see [http://www.epa.gov/pmdesignations].
39 A federally referenced monitor is one that has been accepted for use by EPA for
comparison of the NAAQS by meeting the design specifications and certain precision and
bias (performance) specifications (40 CFR Part 58).
40 Appropriations for monitoring averaged roughly $50 million per year (P.L. 105-65, P.L.
105-226, P.L. 106-74).
41 Information regarding EPA’s guidance for PM designation is available on EPA’s PM
2.5
2.5
website at [http://www.epa.gov/ttn/naaqs/pm/pm25_index.html] and its Policy and Guidance
website at [http://www.epa.gov/ttn/oarpg].

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consistency in future implementation plans. The EPA expected that many of the
PM nonattainment areas would overlap with the eight-hour ozone designations.42
2.5
However, PM designations do not include nonattainment classifications based on
2.5
severity as specified by statute for PM and ozone, which have two and seven
10
classifications, respectively. PM is governed by the general nonattainment
2.5
planning requirements of Title I (Part A and Part D, subpart 1) of the act.
The EPA recognized that determining the geographic extent of nearby source
areas that contribute to nonattainment would be complicated. The CAA does not
specifically require combining neighboring counties within the same nonattainment
area, but it does require the use of metropolitan statistical area boundaries in the more
severely polluted areas (Section 107(d)(4)(A)(iv)). Echoing this requirement, and
similar to the eight-hour ozone approach, EPA recommended that Metropolitan
Statistical Areas or Consolidated Metropolitan Statistical Areas43 serve as the
“presumptive boundary” for nonattainment areas under the 1997 PM standards.
2.5
Metropolitan areas are generally treated as units, even when part of the area lies
in a separate state or does not have readings exceeding the standards. In the latter
case, even though a specific county may not exceed the standards, the pollution
generated there is likely to influence PM levels elsewhere in the metropolitan area.
2.5
In addition, including the entire metropolitan area avoids the creation of additional
incentives for sprawl development on the fringes of urban areas. For rural areas in
violation of the 1997 PM standards, EPA’s guidance presumed that the full county
2.5
would be designated a nonattainment area.
The EPA has generally used its discretion to expand the size of nonattainment
areas or to combine areas that a state listed as separate areas into a single larger unit.
As it did in implementing other NAAQS, EPA also combined nonattainment counties
across state lines into the same nonattainment area, if the counties are part of the
same metropolitan area. Although, according to EPA, staff in the regions and the
agency’s Office of Air Quality Planning and Standards were available for assistance
and consultation throughout the designation process pursuant to the statutory
requirements for working with states, some states disagreed with EPA’s final
designations relative to the states’ own recommendations.
1997 PM Area Designations Timeline
2.5
By the end of February 2004, 18 states and the District of Columbia had
recommended 142 counties as potential nonattainment areas for the 1997 PM2.5
NAAQS.44 After reviewing the state recommendations, EPA proposed modifications
42 A map showing the final designation areas for PM and for the eight-hour ozone NAAQS
2.5
is available on EPA’s website at [http://www.epa.gov/oar/oaqps/greenbk/mappm25o3.html].
43 As defined by the Office of Management Budget. For more information on metropolitan
areas, see [http://www.census.gov/population/www/estimates/aboutmetro.html].
44 For EPA’s final and proposed PM geographical designation recommendations and those
2.5
from individual states and tribes, see [http://www.epa.gov/pmdesignations].

CRS-9
resulting in nonattainment designations for 244 counties45 in 21 states and the District
of Columbia at the end of June 2004. As required by statute, EPA notified each of
the affected states regarding their specific modifications, providing them with the
opportunity to submit new information and demonstrate why a proposed modification
was inappropriate. Some states responding to EPA’s proposal continued to support
their original recommendations.
The EPA’s final PM designation rule, published on January 5, 2005 (70
2.5
Federal Register 944-1019), established the boundaries for areas designated as
“nonattainment,” “unclassifiable” (data not sufficient to make a determination
regarding compliance), or “attainment/unclassifiable.”46 The EPA designated 47
areas, composed of 225 counties in 20 states and the District of Columbia, as
nonattainment; 5 areas consisting of 7 counties as unclassifiable;47 and the remaining
counties in the United States as attainment/unclassifiable.
The EPA’s designations reflected minor modifications to its June 2004 proposal.
Primarily, 19 counties were removed from the list of nonattainment areas, and other
counties were redefined by designating only specified locations (“partial”) within the
county as nonattainment. In some cases, when considering factors defined in its
guidance in conjunction with the additional information provided by the states and
tribes, EPA determined that only those portions of a county that contained the
significant sources of emissions should be considered as contributing to the
violations. In other cases, the agency determined that if emissions from a large
identifiable source in a county contribute to the violations in a nearby area, the
portion of the county where the source is located would be designated nonattainment,
even if it is not contiguous with the remainder of the designated area. The
boundaries for these “noncontiguous” portions are based on legally recognized
government boundaries, such as townships, tax districts, and census blocks.
Some states and stakeholders continued to contend that several counties should
not be designated nonattainment, particularly when taking into account 2004 PM2.5
monitoring data. The EPA’s final designations were based on monitoring data for
the three-year period from 2001-2003. Monitoring data for 2004 were not available
in time for EPA to meet its statutory deadline for PM geographical area
2.5
designations (see timeline and discussion later in this report). The final PM2.5
45 Included seven cities: Baltimore, MD; St. Louis, MO; Alexandria, VA; Fairfax, VA; Falls
Church, VA; Manassas, VA; and Manassas Park, VA.
46 The EPA designates an area as attainment/unclassifiable if (1) monitored air quality data
show that the area has not violated the standard during a three-year period or(2) there is not
enough information to determine the air quality in the area. Despite the CAA, Section
107(d)(1)(A) definitions for “nonattainment,” “attainment,” and “unclassifiable,” EPA does
not apply the “attainment” nomenclature. It is generally the case that the agency has
sufficient data to determine that an area is not in nonattainment, but the data are insufficient
or incomplete to fully determine attainment.
47 The EPA concluded that there was insufficient information to designate these areas as
either nonattainment or attainment/unclassifiable. According to the January 2005 Federal
Register Notice (70 Federal Register 65984), these areas had violating monitors for years
2000-2002 but incomplete data or other data issues for years 2001-2003.

CRS-10
designation rule, published on January 5, 2005, included provisions allowing states
to submit no later than February 22, 2005, certified, quality-assured 2004 monitoring
data that suggest a change in designation is appropriate for consideration (70 Federal
Register
948). A nonattainment designation could be withdrawn if EPA agreed that
the additional data warranted such a change.
On April 14, 2005, EPA published a final supplemental rule amending the
agency’s initial final designations published in January 2005 (70 Federal Register
19844). After reviewing 2002-2004 air quality monitoring data provided by several
states, EPA determined that eight areas comprising 17 counties previously identified
as not meeting the 1997 PM NAAQS should be designated as “in attainment” (see
2.5
Table 1 below). The EPA also changed four of the five areas designated as
“unclassifiable” to “attainment,” based on 2002-2004 data. The EPA did not consider
the modifications for these areas “re-designations” because the changes were made
prior to the April 5, 2005, effective date of the initial designations.
Table 1. Areas Previously Identified as Nonattainment for 1997
PM NAAQS Designated as Attaining the Standards
2.5
State
Area Name
County
Alabama
Columbus, GA-AL
Russell
California
San Diego, CA
San Diego
Georgia
Athens, GA
Clarke
Columbus, GA-AL
Muscogee
Indiana
Elkhart, IN
Elkhart
St. Joseph
Kentucky
Lexington, KY
Fayette
Mercer (partial)
Ohio
Toledo, OH
Lucas
Wood
Youngstown-Warren, OH-PA
Columbiana
Mahoning
Trumbull
Pennsylvania
Youngstown-Warren, OH-PA
Mercer
West Virginia
Marion, WV
Marion
Monongalia (partial)
Harrison (partial)
Source: U.S. Environmental Protection Agency, April 5, 2005. Available at [http://www.epa.gov/
pmdesignations/1997standards/regs.htm].
In letters dated January 20, 2006, EPA denied six petitions submitted to the
agency requesting reconsideration of the previous designations of one or more full
or partial counties as nonattainment for the 1997 PM NAAQS. The petitions were
2.5
for counties in Georgia, Illinois, Michigan, Missouri, Ohio, and West Virginia.48 In
the August 25, 2008, Federal Register, EPA announced its determination that a
48 For more information, see [http://www.epa.gov/pmdesignations/1997standards/regs.htm].


CRS-11
three-county (Harrisburg, Lebanon, Carlisle ) Pennsylvania nonattainment area for
the 1997 PM NAAQS was in attainment.49 The determination was based on
2.5
certified ambient air monitoring data showing that the area has monitored attainment
of the 1997 PM NAAQS since the 2004-2006 monitoring period. As of the end of
2.5
August 2008, final nonattainment designations are in effect for 38 areas, comprising
205 counties within 20 states (and the District of Columbia) nationwide, with a
combined population of almost 90 million. The EPA map in Figure 1 highlights the
PM nonattainment designation areas.
2.5
Figure 1. EPA Designations of Nonattainment Areas for
the 1997 PM National Ambient Air Quality Standards (NAAQS)
2.5
Source: U.S. Environmental Protection Agency, available on EPA’s website at [http://www.epa.gov/
oar/particlepollution/pdfs/20061025_graphsmaps.pdf]. Based primarily on 2001-2003 monitoring
data, but 2002-2004 data was considered for a subset of states. Nonnattainment areas on the above
map include a three-county (Harrisburg, Lebanon, Carlisle ) area in Pennsylvania determined by EPA
in August 2008 to be in attainment.
The designated nonattainment areas for the 1997 PM NAAQS are primarily
2.5
concentrated in the central, mid-Atlantic, and southeastern states east of the
Mississippi River, as well as in California.50 More than 2,900 counties in 30 states
have been designated attainment/unclassifiable for the 1997 PM NAAQS. Some
2.5
public interest groups maintain that at least 150 additional counties warranted
49 73 Federal Register 49949, August 25, 2008.
50 California has established its own PM standards; for more information, see CRS Report
2.5
RL31531 (archived), Particulate Matter Air Quality Standards: Background and Current
Developments
, by Robert Esworthy; or see the California Air Resources Board website at
[http://www.arb.ca.gov/pm/pmmeasures/pmmeasures.htm].

CRS-12
nonattainment designations on the basis of emission sources in those areas.51 Any
area initially designated attainment/unclassifiable may be subsequently re-designated
to nonattainment if ambient air quality data in future years indicate that such a re-
designation is appropriate. Likewise, as was the case for EPA’s determination
regarding the three-county area in Pennsylvania, areas initially designated
nonattainment may be determined to be attainment areas if more current certified
monitoring data support the designation.
Demonstrating Attainment with
the 1997 PM NAAQS
2.5
According to a January 2008 EPA report entitled, Latest Findings on National
Air Quality Status and Trends Through 2006,52 nationally, annual PM2.5
concentrations declined by 14% between 2000 and 2006. For PM , the areas that
2.5
showed the greatest improvement were the ones that had the highest concentrations
in earlier years, including Southern California and the industrial Midwest and the
Northeast. The Southeast had little change in PM .
2.5
Despite this progress, in 2006, nearly 67 million people lived in counties with
measured concentrations exceeding the annual PM national air quality standard
2.5
(based on a one-year metric, not the three-year average).53 A report released by the
American Lung Association (ALA) in April 2007 indicated higher average
concentration levels of year-round PM in densely populated areas of the eastern
2.5
United States during 2003-2005, compared with 2002-2004. The report noted that
outside of the eastern United States, particle levels continued to drop during the same
time period, even in areas that the ALA has historically ranked as high in particle
pollution.54 Achieving attainment of the 1997 PM NAAQS is expected to further
2.5
reduce exposure to fine particulate matter; overall, EPA estimated that attainment of
the 1997 PM NAAQS would annually result in the avoidance of at least 3,300 to
2.5
15,600 incidences of premature mortality nationwide.55
51 American Lung Association, “No One Should Have to Breathe Unsafe Air,” December
17, 2004; press release available at [http://www.lungusa.org/site/c.dvLUK9O0E/b.4061173/
apps/s/content.asp?ct=323661].
52 EPA-454/R-07-007, January 2008 [http://www.epa.gov/air/airtrends/2007/].
53 Refers to trends in the measured PM concentrations relative to their air quality standards
2.5
in those areas where monitors are located across the country, and does reflect all designated
nonattainment areas. The combined population residing in EPA’s final PM nonattainment
2.5
designation areas, consisting of 205 counties in 20 states and the District of Columbia, is
almost 90 million.
54 Estimates are based on air quality data obtained from the U.S. Environmental Protection
Agency’s Air Quality System (AQS), formerly called Aerometric Information Retrieval
System (AIRS). American Lung Association, State of the Air: 2007, released April 2007,
[http://lungaction.org/reports/stateoftheair2007.html].
55 EPA, Regulatory Impact Analysis for the Particulate Matter and Ozone National Ambient
Air Quality Standards and Proposed Regional Haze Rule
, July 1997, p. ES-18. Available
(continued...)

CRS-13
The State Implementation Plan (SIP)
Following the designation of an area as nonattainment, the state where the area
is located must develop a State Implementation Plan (SIP) that demonstrates how
attainment with the PM standards will be achieved. Under Section 110 of the CAA,
2.5
states must submit their SIPs to EPA within three years of designation; 1997 PM2.5
NAAQS SIPs were due April 5, 2008. To be approved, a SIP must demonstrate that
the area will reach attainment of the standards by a specified deadline — 2010 for
1997 PM NAAQS unless an extension allowed under the CAA is granted.56
2.5
SIPs include pollution control measures that will be implemented by federal,
state, and local governments, and rely on models of the impact on air quality of
projected emission reductions to demonstrate attainment. According to EPA, nine of
the 57 SIPs (there are 38 areas, but some have multiple states submitting individual
SIPs) had been submitted as of the end of August 2008.57 States with nonattainment
areas must be in compliance with the 1997 PM NAAQS by April 5, 2010, unless
2.5
they are granted an extension.
EPA’s PM Implementation Rule
2.5
On April 25, 2007, EPA published its final rule58 that describes the requirements
that states and tribes must meet in their implementation plans to achieve and maintain
attainment of the 1997 PM NAAQS.59 In addition to detailing provisions necessary
2.5
to demonstrate how the PM NAAQS will be attained, the implementation rule
2.5
includes guidance for submitting a SIP demonstrating that reaching attainment within
the five-year requirement is impractical. A number of provisions that generated
several comments during the proposal were retained in the final rule,60 and continue
55 (...continued)
at [http://www.epa.gov/ttn/oarpg/naaqsfin/ria.html], also see CRS Report RL31531
(archived), Particulate Matter Air Quality Standards: Background and Current
Developments
, by Robert Esworthy, for more detail discussion of EPA’s review and findings
regarding the scientific health effects data in support of the 1997 PM NAAQS.
2.5
56 Under section 172(a)(2)(A) of the CAA, EPA may grant an area an extension of the initial
attainment date for one to five years (in no case later than 10 years after the designation date
for the area). A state requesting an extension must submit an implementation plan (SIP) by
the required deadline that includes, among other things, sufficient information
demonstrating that attainment by the initial attainment date is “impracticable.”
57 Information provided directly to CRS by the EPA Office of Air Quality Planning and
Standards (OAQPS) based on consultation with the EPA Regions.
58 72 Federal Register 20586-20667, April 25, 2007.
59 The rule addresses attainment demonstration and modeling; local emission reduction
measures, including reasonably available control technology (RACT), reasonably available
control measures (RACM), and reasonable further progress (RFP); regional emission
reduction strategies; innovative program guidance; emission inventory requirements;
transportation conformity; and stationary source test methods.
60 Each section of the final April 25, 2007, PM implementation rule (72 Federal Register
2.5
(continued...)

CRS-14
to be the topic of debate. As noted earlier, petitions for legal review of EPA’s
implementation rule have been filed with the U.S. Court of Appeals for the D.C.
Circuit, and two petitions for reconsideration have been filed with EPA.
Transportation Conformity
If new or revised SIPs for PM attainment establish or revise a transportation-
2.5
related emissions budget, or add or delete transportation control measures (TCMs),
they trigger “conformity” determinations. Transportation conformity is required by
the CAA, Section 176(c) (42 U.S.C. 7506(c)), to prohibit federal funding and
approval for highway and transit projects unless they are consistent with (“conform
to”) the air quality goals established by a SIP and will not cause new air quality
violations, worsen existing violations, or delay timely attainment of the national
ambient air quality standards. Conformity becomes applicable within one year of the
effective date of designating an area as nonattainment. EPA has promulgated several
transportation conformity rules and rule amendments since its enactment as part of
the 1990 CAA.61 The rules generally establish the criteria and procedures for
determining whether transportation plans, transportation improvement programs
(TIPs), or projects conform to a state’s SIP.
On July 1, 2004, EPA published a final rule62 making transportation conformity
regulations applicable explicitly to PM nonattainment areas and included criteria
2.5
and procedures for the new PM and eight-hour ozone NAAQS. On May 6, 2005,
2.5
EPA published a final rule63 further amending the transportation conformity
regulations by adding transportation-related PM “precursors” and specifying when
2.5
these precursors must be considered in conformity determinations before and after
PM SIPs are submitted.64 The EPA established the criteria for determining which
2.5
60 (...continued)
20586-20667) summarizes policies and options discussed in the proposed rule, and provides
responses to the major comments received on each issue. Comments and other supporting
materials are available the docket established for this rule (ID-HQ-OAR-2003-0062)
electronically at [http://www.regulations.gov] or in hard copy at the EPA Docket Center.
61 The initial conformity rule was promulgated by EPA on November 24, 1993 (58 Federal
Register
62188), and has subsequently been amended several times; see EPA’s
“Chronological List of Transportation Conformity Rulemakings” at [http://www.epa.gov/
otaq/stateresources/transconf/conf-regs-c.htm], and “Transportation Conformity Regulations
Current as of January 2008,” EPA420-B-08-001, January 2008, [http://www.epa.gov/otaq/
stateresources/transconf/regs/420b08001.pdf].
62 69 Federal Register 40004, July 1, 2004. See also Companion Guidance for the July 1,
2004, Final Transportation Conformity Rule: Conformity Implementation in Multi-
Jurisdictional Nonattainment and Maintenance Areas for Existing and New Air Quality
Standards
, EPA, July 2004, EPA420-B-04-012, Transportation and Regional Programs
Division, Office of Transportation and Air Quality, available at [http://www.epa.gov/otaq/
stateresources/transconf/policy.htm].
63 70 Federal Register 24280, May 6, 2005.
64 Precursors are pollutants that react chemically in the atmosphere to form other pollutants.
The transportation-related PM precursors identified in the May 2005 rule are nitrogen
2.5
(continued...)

CRS-15
transportation projects must be analyzed for local particle emissions (referred to as
“hot spots”65) in PM nonattainment and maintenance areas, and revised existing
2.5
requirements for projects in PM areas, in a final rule published on March 10,
10
2006.66 Although petitioners challenged certain provisions of the July 2004 and
March 2006 final rules with varying results,67 all PM nonattainment areas have
2.5
completed their initial transportation conformity determinations, and as a result their
transportation plans and programs conformed to the 1997 PM NAAQS according
2.5
to EPA.68
Upwind Pollutant Contributions: § 126 of the CAA
Whether any special consideration can be given to areas whose air quality is
adversely affected by pollution from upwind areas is one of the more frequently
raised issues in nonattainment areas. Unlike the larger coarse particles, which
generally settle more rapidly and fall near their source of emission, the smaller PM2.5
particles frequently remain in the atmosphere longer and can travel significant
distances from their original source. The transport of PM can contribute to, and in
2.5
some cases can be the primary cause of, nonattainment in areas downwind of an
emission source.
Subpart 1 of the CAA allows EPA to “classify the area for the purpose of
applying an attainment date” and to consider such factors as “the availability and
feasibility of pollution control measures.” As referenced in the proposed PM2.5
implementation rule, areas also may petition the agency under § 126 of the CAA to
impose controls on upwind sources that significantly contribute to their
nonattainment of the standard. The May 2005 promulgation of CAIR69 was expected
to address the interstate transport of pollutants (SO and NOx) from electric
2
generating units (EGUs) hindering downwind states from attaining the eight-hour
64 (...continued)
oxides (NOx), volatile organic compounds (VOCs), sulfur oxides (SO ), and ammonia
2
(NH ). See [http://www.epa.gov/otaq/stateresources/index.htm].
3
65 The CAA defines “hot-spot analysis” as an estimation of likely future localized pollutant
concentrations resulting from a new transportation project and a comparison of those
concentrations to the relevant air quality standard (40 CFR 93.101).
66 71 Federal Register 12468, March 10, 2006.
67 For findings by the U.S. Court of Appeals for the D.C. Circuit, see Environmental Defense
v. EPA, No. 04-1291 (D.C. Cir. October 20, 2006), and Natural Resources Defense Council,
Environmental Defense, and Sierra Club. Environmental Defense v. EPA, No. 06-1164
(D.C. Cir. December 2006).
68 Information provided to CRS by EPA’s Office of Air Quality and Planning, April 17,
2008.
69 Environmental Protection Agency, Rule to Reduce Interstate Transport of Fine
Particulate Matter and Ozone (Clean Air Interstate Rule); Revisions to Acid Rain Program;
Revisions to the NOx SIP Call; Final Rule
(70 Federal Register 25162-25405, May 12,
2005), p. 25246.

CRS-16
ozone and 1997 PM NAAQS.70 However, the D.C. Circuit Court’s decision 71 to
2.5
vacate CAIR puts the focus back on § 126 petitions as the available means to address
interstate transport of air pollutants in the immediate future.72
EPA has never granted a § 126 petition in the manner outlined by the statute.73
Most recently, it denied a 2004 § 126 petition from the State of North Carolina for
several reasons, in part arguing that CAIR was a better mechanism for addressing the
interstate transport of pollution to which North Carolina was subject than was the
state’s petition under § 126. North Carolina challenged this denial in court. Its
challenge was stayed, pending the outcome of the CAIR lawsuit, of which North
Carolina was a petitioner. (See additional discussion later in this report under “D.C.
Circuit’s Decision Vacating CAIR.”)
Grant Programs
Although EPA does not have a grant program specifically designed to assist
nonattainment areas, the agency generally provides grants to state air pollution
agencies in support of their programs. Other sources of funding are also available.
For example, states may obtain funding for projects intended to contribute to the
attainment or maintenance of NAAQS under the Department of Transportation’s
(DOT’s) Congestion Mitigation and Air Quality Improvement Program (CMAQ).
Congress authorized $8.6 billion for this program for FY2005-FY2009 under the
Safe, Accountable, Flexible and Efficient Transportation Equity Act: A Legacy for
Users (SAFETEA-LU) (P.L. 109-59), signed into law on August 10, 2005.
Authorized initially by Congress under the Intermodal Surface Transportation
Efficiency Act of 1991 (ISTEA, P.L. 102-240) and funded by the Highway Trust
Fund, CMAQ provides funding for surface transportation and other related projects
that contribute to air quality improvements and congestion mitigation. In particular,
the program is authorized to fund projects that contribute to the reduction of carbon
monoxide (CO) and ozone concentrations. CMAQ funds are apportioned to a state
70 Sulfur dioxide (SO ) is a precursor contributing to the formation of PM concentrations,
2
2.5
and NOx is a precursor (a pollutant that is transformed in air to form another air pollutant)
contributing to the formation of both ozone and PM concentrations. EPA has concluded
2.5
that SO and NOx emissions, through the phenomenon of air pollution transport, contribute
2
significantly to downwind nonattainment, or interfere with maintenance, of the PM and
2.5
eight-hour ozone NAAQS. 70 Federal Register 25162, May 12, 2005.
71 531 F.3d 896 (D.C. Cir. 2008).
72 For a more detailed discussion of the court’s decision and its implications, see CRS
Report RL34589, Clean Air After the CAIR Decision: Back to Square One?, by James E.
McCarthy, Larry Parker, and Robert Meltz.
73 Petitions regarding NAAQS other than PM have been filed with the agency; the most
2.5
well-known are those that were filed in August 1997 by eight northeastern states, four of
which were granted by the agency in January 2000. See CRS Report 98-236, Air Quality:
EPA’s Ozone Transport Rule, OTAG, and Section 126 Petitions — A Hazy Situation?
, by
Larry Parker and John Blodgett (available from the authors).

CRS-17
based on its population and pollution reduction needs.74 States with no maintenance
or nonattainment areas for ozone or CO are guaranteed a minimum of 0.5% of each
fiscal year’s authorized CMAQ funds.
CMAQ was expanded to allow the use of funds for projects intended to reduce
particulate concentrations under the Transportation Equity Act for the 21st Century
(TEA-21, P.L. 105-178). TEA-21 did not, however, change the apportionment
formula that is based on CO and ozone. States with maintenance or nonattainment
areas for only particulates receive the guaranteed minimum.75
Recent Actions and Their Implications for Achieving
Attainment of the 1997 PM NAAQS
2.5
A number of events, most notably the D.C. Circuit Court’s July 2008 decision
regarding the Clean Air Interstate Rule (CAIR), EPA’s final 2006 revisions of the
PM NAAQS, and actions regarding implementation of the agency’s eight-hour ozone
NAAQS, are directly affecting the timely implementation of the 1997 PM NAAQS.
2.5
The D.C. Circuit’s decision to vacate CAIR, in particular, could result in significantly
delays, but each of these issues has garnered attention in Congress.
D.C. Circuit’s Decision Vacating the
Clean Air Interstate Rule (CAIR)76

The EPA’s Rule to Reduce Interstate Transport of Fine Particulate Matter and
Ozone, or the Clean Air Interstate Rule (CAIR), published in May 2005, was
expected to address the interstate transport of pollutants (SO and NOx) from electric
2
generating units (EGUs) hindering downwind states from attaining the eight-hour
ozone and 1997 PM NAAQS.77 On July 11, 2008, the U.S. Court of Appeals for
2.5
74 For the FY2008 apportionment of CMAQ funds, see the U.S. Department of
Transportation Federal Highway Administration Notice: Revised Apportionment of Fiscal
Year (FY) 2008 Congestion Mitigation & Air Quality Improvement Program Funds,
January 30, 2008, [http://www.fhwa.dot.gov/legsregs/directives/notices/n4510675.htm]; for
prior years, see [http://www.fhwa.dot.gov/legsregs/directives/notices.htm].
75 For a more detailed discussion of CMAQ and relevant legislation, see CRS Report
RL33119, Safe, Accountable, Flexible, Efficient Transportation Equity Act — A Legacy for
Users (SAFETEA-LU or SAFETEA): Selected Major Provisions
, by John W. Fischer; and
CRS Report RL33057 Surface Transportation Reauthorization: Environmental Issues and
Legislative Provisions in SAFETEA-LU (H.R. 3)
, by Linda Luther.
76 For a more detailed discussion of the court’s decision and its implications, see CRS
Report RL34589, Clean Air After the CAIR Decision: Back to Square One?, by James E.
McCarthy, Larry Parker and Robert Meltz.
77 Sulfur dioxide (SO ) is a precursor contributing to the formation of PM concentrations,
2
2.5
and NOx is a precursor (a pollutant that is transformed in air to form another air pollutant)
contributing to the formation of both ozone and PM concentrations. EPA has concluded
2.5
that SO and NOx emissions, through the phenomenon of air pollution transport, contribute
2
(continued...)

CRS-18
the D.C. Circuit issued its decision vacating CAIR,78 though the decision will not
take effect until further developments in the court have occurred.
Although CAIR generally had broad support among environmentalists and many
in the regulated community, no less than 32 petitions79 for review of CAIR were
consolidated and decided in North Carolina v. EPA. Some, including the State of
North Carolina,80 argued that the rule was not strong enough to address pollution
from upwind sources. Others, mostly individual utilities, contended that the rule’s
emission budgets would disproportionally affect certain operations and facilities.
The D.C. Circuit found several of the key challenges valid, but decided against
voiding only the successfully challenged portions. Noting that EPA regards CAIR
as one integrated action, the court’s decision would vacate the entire rule (and its
associated Federal Implementation Plan) and remand it to EPA.
In developing CAIR, with respect to the 1997 PM NAAQS, EPA modeled the
2.5
emissions impacts of 37 eastern states on 62 eastern downwind counties projected
by EPA to be in nonattainment in 2010.81 EPA found 23 states and the District of
Columbia were projected to contribute significantly to 2010 PM nonattainment.
2.5
These states and the District constitute the region covered under CAIR’s annual NOx
and SO caps. Based on air quality analyses in support of the CAIR, EPA predicted
2
that 17 of 36 areas in the eastern United States designated as nonattainment (out of
compliance) with the 1997 PM NAAQS would reach attainment by 2010 as a result
2.5
of implementing CAIR in conjunction with other existing national programs.82 On
the other hand, the EPA analyses recognized that as many as 19 of the areas would
remain in nonattainment, highlighting the importance of local and state emission
reduction efforts. The extent of pollution reduction projected to result from
implementing CAIR had been the subject of considerable debate among stakeholders
and some Members of Congress for some time prior to the July 2008 D.C. Circuit
decision to vacate the rule.83
77 (...continued)
significantly to downwind nonattainment, or interfere with maintenance, of the PM and
2.5
eight-hour ozone NAAQS. 70 Federal Register 25162, May 12, 2005.
78 531 F.3d 896 (D.C. Cir. 2008).
79 EPA’s CAIR “Regulatory Actions” website, at [http://www.epa.gov/cair/rule.html],
presents overviews of these challenges and the agency’s responses chronologically. The
complete petitions are available in the docket for the CAIR, Docket ID No. EPA-HQ- OAR-
2003-0053, at [http://www.regulations.gov].
80 Prior to the publication of the final CAIR rule, North Carolina filed a petition in March
2004 under Section 126 of the federal CAA, which allows states to seek federal intervention
on transboundary air pollution. The petition, settlement (North Carolina v. Johnson, No.
5:05-CV-112-BR(3), February 17, 2005, E.D.N.C), and subsequent actions regarding this
petition can also be found in the CAIR Docket.
81 Clean Air Interstate Rule, p. 25247.
82 See page 66006 of 70 Federal Register 65984, November 1, 2005, Proposed Rule to
Implement the Fine Particle National Ambient Air Quality Standards
.
83 For more information on the CAIR, see CRS Report RL32927, Clean Air Interstate Rule:
(continued...)

CRS-19
Under EPA’s implementation guidance for the SIPs outlining states’ strategies
for complying with the 1997 PM NAAQS, carrying out the CAIR would have met
2.5
the interstate transport (downwind state) provision of § 110(a)(2)(D) of the CAA.
As litigation regarding certain aspects of CAIR was pending, EPA reported that its
implementation was continuing.84 According to EPA, all the states covered under
CAIR chose to participate in the trading programs for SO and NOx (or
2
acknowledged an EPA Federal Implementation Plan (FIP) as a default); some also
have established direct control programs complementing the trading programs.
States had been working to put implementing rules in place, and some in the
regulated community had been going forward with investing in equipment for CAIR.
The court’s decision regarding CAIR presents a major setback to the
implementation of the 1997 PM (and ozone) NAAQS. EPA’s Director of
2.5
Atmospheric Programs testified before Congress that
[i]n many cases, states in the CAIR region have relied heavily on the emission
reductions required by CAIR as they conducted their modeling to show that they
will meet the 1997 ambient air quality standards on time. These attainment
demonstration components of the SIPs will likely need to be revised to show how
the states will achieve the emission reductions previously required by CAIR.85
The vacating of CAIR means that SIPs from downwind states may be
inadequate because they assumed the CAIR reductions in interstate transport of
pollutants. SIPS from upwind states, on the other hand, could be inadequate if they
do not prevent downwind nonattainment: the CAA makes clear that states are to
impose controls on stationary sources of pollution that contribute significantly to
downwind nonattainment or interfere with the maintenance of air quality standards
in other states (§ 110(a)(2)(D)). This provision of the statute has been widely
disregarded in the past, with little EPA effort (other than regional cap-and-trade
programs) to address it. This reluctance to act can be challenged through CAA § 126
petitions, and the court’s decision puts the focus on these petitions as the available
means of addressing interstate transport of air pollutants in the immediate future.
As discussed previously, EPA has never granted a § 126 petition in the manner
outlined by the statute. On August 8, 2008, the State of North Carolina petitioned the
D.C. Circuit to resume its 2007 lawsuit challenging EPA’s denial of its 2004 § 126
petition. EPA had denied the earlier petition primarily based on the outcomes
provided by CAIR. The lawsuit had been placed on hold by the D.C. Circuit pending
its decision regarding challenges to CAIR. A decision in North Carolina’s favor
83 (...continued)
Review and Analysis, by Larry Parker, and CRS Report RL32273, Air Quality: EPA’s
Proposed Interstate Air Quality Rule
, by Larry Parker and John Blodgett.
84 Acid Rain and Related Programs: 2006 PROGRESS REPORT, EPA-430-R-07-011,
November 2007, [http://www.epa.gov/airmarkets/progress/docs/2006-ARP-Report.pdf].
85 Testimony of Mr. Brian McLean, Director of Atmospheric Programs, Office of Air and
Radiation, U.S. EPA, before the Senate Committee on Environment and Public Works,
Subcommittee on Clean Air and Nuclear Safety, July 29, 2008, [http://epw.senate.gov/
public/].

CRS-20
would seem much more likely, as the D.C. Circuit decision in the CAIR case notes
that “downwind states retain their statutory right to petition for immediate relief from
unlawful interstate pollution under section 126.”86 A court finding in favor of North
Carolina’s § 126 petition might, therefore, bring on numerous § 126 petitions from
other states. On August 11, 2008, EPA and interveners motioned the D.C. Circuit to
hold in abeyance the case regarding the denial of North Carolina’s § 126 petition.
On September 24, 2008, EPA requested reconsideration of the court’s July 2008
decision, with suggestion for rehearing en banc (that is, a rehearing by the entire
court), as did the Natural Resources Defense Council (NRDC), the National Mining
Association, and the Utility Air Regulatory Group, in separate petitions. Granting
reconsideration or a rehearing en banc is unusual, and success is especially unlikely
given that the initial North Carolina v. EPA decision was unanimous and appeared
to give the court little pause. Granting a rehearing requires the vote of a majority of
the active duty judges on the D.C. Circuit. As requested by the court, a new round of
legal briefings was filed in early November 2008. In a brief submitted on behalf of
EPA November 17, 2008, the U.S. Department of Justice continued to support the
request in the petition for a rehearing, but said that a stay of the decision long enough
to allow implementation of a replacement regulatory regime would be preferable to
complete vacatur.
Deadlines are fast approaching for states in nonattainment to submit SIPs and
reach attainment of the 1997 PM (and ozone) NAAQS. It is also unclear whether
2.5
the agency can salvage the regional cap-and-trade approach, which lies at the heart
of CAIR, or if cap-and-trade on a smaller scale, whether intrastate or intra-company,
would face better odds.87 The court found “more than several fatal flaws”88 in the
rule, and concluded, “No amount of tinkering will transform CAIR, as written, into
an acceptable rule.”89 This raises the question of whether Congress might intervene
(see discussion under “Congressional Action Related to Particulates NAAQS
Implementation,” later in this report).
86 531 F.3d at 930 (D.C. Cir. 2008)
87 Allowing even modest emissions trading can significantly reduce costs. Estimates made
during the development of the acid rain trading program indicated that intra-utility trading
reduced costs by half over a plant-by-plant control program, while including intrastate
trading reduced costs by an additional 10%. Further expansion to interstate trading reduced
costs an additional 10%. See Larry B. Parker, Robert D. Poling, and John L. Moore, “Clean
Air Act Allowance Trading,” 21 Environmental Law, 2021, 2022-2068 (1991).
88 531 F.3d at 901 (D.C. Cir. 2008).
89 531 F.3d at 930 (D.C. Cir. 2008).

CRS-21
Completion of EPA’s Review of the Particulates NAAQS
and the September 2006 Changes90

At the end of 2005, EPA completed its statutorily required91 review and
assessment of relevant scientific studies to either reaffirm or modify the particulates
NAAQS. Based on the review, on October 17, 2006, EPA promulgated revisions to
the particulates NAAQS.92 Given the simultaneity of the 2006 particulates NAAQS
as revised and the ongoing implementation of the 1997 PM
standards, outcomes
2.5
and challenges associated with the review and EPA’s changes to the existing (1987
and 1997) NAAQS for PM and PM could affect the implementation schedule for
10
2.5
the 1997 PM NAAQS.
2.5
Based on its review and analysis of scientific studies available between 1997
and 2002,93 and determinations made by the Administrator, EPA’s modifications to
the particulates NAAQS tightened the current NAAQS primarily by strengthening
the daily (24-hour) standard for PM . The 2006 NAAQS lowered the daily PM
2.5
2.5
standard from 65 micrograms per cubic meter (µg/m3) to 35 µg/m3 and retained the
annual standard at 15 µg/m3. The EPA left the existing (1987) daily standard for
coarse particles (PM ) in place at 150 µg/m3 and relaxed the standard somewhat by
10
revoking the existing annual maximum concentration standard of 50 µg/m3.
EPA’s tightening of the PM NAAQS will result in the classification of more
2.5
areas as “nonattainment” and in need of implementing new controls on particulate
matter. States and local governments will be required to develop and implement new
plans (SIPs) for addressing emissions in those areas that do not meet any new
standards. In a February 2006 advanced notice of proposed rulemaking (ANPR)94
outlining an implementation plan for the transition to the 2006 particulates standards,
EPA indicated that it would be beneficial for states to consider control strategies that
may be useful in attaining the 2006 revised PM NAAQS when developing their
2.5
strategies for the 1997 PM standards.
2.5
In December 2007, states provided EPA with recommended nonattainment
boundaries for the 2006 PM NAAQS based on 2004-2006 monitoring data. EPA
2.5
responded to the states with the agency’s intended designations of areas not in
attainment with the 2006 PM NAAQS in letters dated August 19, 2008, and
2.5
90 For more information regarding of EPA’s changes to the particulates NAAQS, see CRS
Report RL33254, Air Quality: EPA’s 2006 Changes to the Particulate Matter (PM)
Standard
, by Robert Esworthy and James E. McCarthy. Information can also be accessed
on EPA’s website at [http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html].
91 Section 109(d)(1)) of the CAA.
92 71 Federal Register 61143-61233, October 17, 2006.
93 EPA, Air Quality Criteria for Particulate Matter, October 29, 2004. EPA, Review of the
National Ambient Air Quality Standards for Particulate Matter: Policy Assessment of
Scientific and Technical Information, OAQPS Staff Paper
, Office of Air Quality Planning
and Standards, EPA-452/R-05-005, July 2005. The EPA criteria document and staff paper
can are available at [http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_cr.html].
94 71 Federal Register 6718, February 9, 2006.

CRS-22
solicited the states’ comments and additional information for consideration in
determining the final designations.95 The agency identified 169 counties and portions
of 46 additional counties for designation as nonattainment. States (and tribal groups)
had 120 days to respond to EPA’s recommendations, and the agency also issued a
notice96 for a 30-day public comment period. EPA expects to finalize these
nonattainment designations (based on 2005-2007 monitoring data) by the end of
2008, with an effective date of April 2009. The associated impacts on specific
geographical nonattainment areas would be speculative at best, because
implementation of the 2006 particulates NAAQS is several years off. States will not
be required to submit SIPs until 2013, and would not have to meet the new PM2.5
standard until April 2014 (or April 2020, if qualified for an extension97). For the
1997 PM NAAQS, states were required to submit implementation plans for how
2.5
they will meet the standards by April 2008, and must be in compliance by 2010,
unless granted an extension.98
In December 2006, several states and industry, agriculture, business, and public
advocacy groups separately petitioned the court to review the 2006 particulates
NAAQS.99 These challenges could affect the current implementation schedule for the
1997 PM NAAQS.
2.5
Congressional Action Related to
Particulates NAAQS Implementation
Concerns regarding the potential impacts of the ozone and particulate standards
have led to several attempts by Congress over the years to modify the implementation
requirements.100 Attempts in recent years were generally attached to larger pieces of
legislation, such as the energy101 and transportation bills, as well the proposed multi-
pollutant (Clear Skies) bills to reduce emissions from coal-fired power plants.
95 For information regarding EPA’s proposed designations, including correspondence
between EPA and state and tribal representatives, see [http://www.epa.gov/pmdesignations/
2006standards/regs.htm#2].
96 73 Federal Register 51257, September 2, 2008.
97 Under § 172(a)(2)(A) of the CAA, EPA may grant an area an extension of the initial
attainment date for one to five years (not later than 10 years after the designation date for
the area). A state requesting an extension must submit an implementation plan (SIP) by the
required deadline that includes, among other things, sufficient information demonstrating
that attainment by the initial attainment date is “impracticable.”
98 Ibid.
99 The Court consolidated the cases at American Farm Bureau Federation v. U.S. EPA, No.
06-1410 (D.C. Cir. 2006).
100 For a historical perspective, see CRS Report RL34057, Ozone Air Quality Standards:
EPA’s 2007 Proposed Changes
, by James E. McCarthy; and CRS Report RL33552, Clean
Air Act Issues in the 109th Congress
, by James E. McCarthy.
101 See CRS Report RL32873, Key Environmental Issues in the Energy Policy Act of 2005
(P.L. 109-58, H.R. 6)
, by Brent D. Yacobucci.

CRS-23
Although PM was not one of the primary pollutants102 specified in the multi-
2.5
pollutant legislation previously considered, certain provisions of some of the bills
could have potentially contributed to reducing PM concentrations.103
2.5
The D.C. Circuit’s decision that would vacate CAIR puts into play again the
issue of a multi-pollutant strategy with respect to the electric utility industry — a
framework based on a consistent set of emissions caps implemented through
emission trading. Such an approach would not resolve all the issues surrounding
CAIR, and would raise issues of its own:104
! Should multi-pollutant legislation supplement or be a substitute for
the current regulatory regime?
! How stringent should the emission caps be?
! What is an appropriate schedule for their introduction?
! How should they relate to existing CAA provisions?
! Should carbon dioxide be included with SO , NOx, and mercury
2
control programs?
! Should requirements be limited to the electric utility industry?
! Should EPA be provided with the authority to implement CAIR or
other cost-based, market-oriented approaches to address NAAQS?
! Should there be comprehensive revision to the CAA to address the
full scope of ozone and PM NAAQS nonattainment and related
2.5
issues, as well as other pollutant emissions from coal-fired
powerplants, and emerging environmental issues such as climate
change?
Congress could consider a more surgical legislative vehicle aimed specifically
at providing EPA with the authority to implement CAIR or other cost-based, market-
oriented approaches to address NAAQS. At the other extreme, Congress might
consider a more comprehensive revision to the CAA to address not only ozone and
PM NAAQS nonattainment, but also mercury emissions from coal-fired
2.5
powerplants, and emerging environmental issues such as climate change.
102 Bills introduced in previous Congresses generally focused on regulating three or four
pollutants; three-pollutant bills addressed sulfur dioxide (SO ), nitrogen oxides (NOx), and
2
mercury (Hg) emissions, and the four-pollutant bills added carbon dioxide (CO )
2
103 During the 110th Congress, five multi-pollutant bills have been introduced. The proposed
bills, S. 1168, S. 1177, S. 1201, S. 1554, and H.R. 3989, would establish a regulatory
program to reduce the quantities of sulfur dioxide (SO ), nitrogen oxides (NOx), mercury
2
(Hg), and carbon dioxide (CO ) emissions from the electric generating sector. No action has
2
been scheduled as of this writing. For information and a comparison of legislative proposals,
see CRS Report RL34018, Air Quality: Multi-Pollutant Legislation in the 110th Congress,
by Larry Parker and John Blodgett. For a comparison of bills in the 109th Congress,
including the Clear Skies bill, see CRS Report RL32755, Air Quality: Multi-Pollutant
Legislation in the 109th Congress
, by Larry Parker and John Blodgett.
104 See CRS Report RL34589, Clean Air After the CAIR Decision: Back to Square One?, by
James E. McCarthy, Larry Parker and Robert Meltz.

CRS-24
These questions and related issues were at the center of discussion during the
July 29, 2008, hearing held by the Senate Committee on Environment and Public
Works’s Subcommittee on Clean Air and Nuclear Safety.105
Conclusion
Implementation of the 1997 PM NAAQS is affecting a number of counties
2.5
throughout the United States. Nonattainment designations are in effect for 38 areas,
comprising 205 counties within 20 states (and the District of Columbia) nationwide,
with a combined population of almost 90 million. A number of concerns have been
raised regarding the potential impacts, and numerous questions have been triggered
regarding the specifics of the implementation process for the 1997 standards.
Implementation of the 1997 PM NAAQS, already delayed considerably, is
2.5
threatened with further delay as a result of the U.S. Court of Appeals for the D.C.
Circuit’s July 11, 2008, decision (North Carolina v. EPA) that would vacate the
Clean Air Interstate Rule (CAIR).106
EPA projected that CAIR, in conjunction with other federal measures such as
recent auto and truck emission standards, would be sufficient to demonstrate
attainment in a large portion of monitored nonattainment counties by 2015, prior to
the development and implementation of local measures. Promulgated by EPA under
the CAA in May 2005, CAIR would have established a regional cap-and-trade
program for sulfur dioxide (SO ) and nitrogen oxide (NOx) emissions107 from electric
2
generating units (EGUs) in 28 eastern states and the District of Columbia.108
Specifically calling for a combination of local and interstate transport control, EPA’s
CAIR rulemaking developed criteria for determining “highly cost-effective” transport
control levels to mitigate interstate transport of SO and NOx contributing
2
significantly to PM (and ozone) nonattainment. While some Members of Congress
2.5
and others questioned EPA’s predictions regarding the relative magnitude of the
emission reductions associated with existing and proposed air quality controls, the
vacating of CAIR is seen as significantly hampering downwind states’ ability to
achieve emission reductions and compliance with the 1997 PM (and ozone)
2.5
NAAQS.
105 Senate Committee on Environment and Public Works, Subcommittee on Clean Air and
Nuclear Safety, hearing, “EPA’s Clean Air Interstate Rule (CAIR): Recent Court Decision
and its Implications,” July 29, 2008, [http://epw.senate.gov/public/].
106 42 U.S.C. 7401 et seq.
107 SO emissions cause acid precipitation, and SO is also among the pollutants that form
2
2
fine particles (PM ) in the atmosphere. NOx contributes to both PM and to the formation
2.5
2.5
of ground-level ozone.
108 While virtually all eastern states were affected by the rule, three were subject only to the
SO -NOx annual caps, and five only to the seasonal NOx cap; the other 20 states and DC
2
were subject to all three caps. See EPA Fact Sheet, p. 3, at [http://www.epa.gov/CAIR/pdfs/
cair_final_fact.pdf].

CRS-25
CAIR has been viewed as the linchpin that held together the Administration’s
strategy for improving air quality through not only the attainment of the ozone and
fine particulate NAAQS, but also by achieving reductions in mercury emissions from
coal-fired powerplants, by addressing regional haze impacts from powerplants, and
by responding to state petitions to control upwind sources of ozone and fine
particulate pollution under § 126 of the CAA. The court’s decision that would vacate
CAIR presents all stakeholders with a complicated task. As advised by EPA
guidance, many SIPs for demonstrating attainment of the 1997 PM NAAQS already
2.5
submitted or nearing completion have relied on emission reductions required by
CAIR. These SIPs will have to be revised, and downwind states may have to rely on
provisions in § 126 of the CAA to address interstate transport of PM , unless the
2.5
intent of CAIR can somehow otherwise be revived.
Time is in short supply for states and cities in nonattainment. Although EPA and
others have requested a rehearing en blanc of the July 2008 decision, whether the
court would grant such rehearing is in question. Whatever the outcome and course(s)
of action taken, deadlines for states to submit their SIPs for 1997 PM NAAQS have
2.5
elapsed, and deadlines for reaching attainment are looming. Given the most recent
events and the potential for further delays in implementing the 1997 standards, some
have questioned whether moving directly to implementation of the revised
particulates NAAQS promulgated by EPA in October 2006 should be considered.
However, opponents contend that an approach relying on the schedule for the 2006
revised particulates NAAQS would further delay the projected benefits of reducing
exposures to PM . In addition, the 2006 revised particulates NAAQS have sparked
2.5
their own controversies and have been challenged in the courts.
Given that several key implementation milestones and attainment deadlines are
nearing, PM will likely remain an issue of considerable debate for many
2.5
stakeholders and interest groups, as well as Congress.

CRS-26
Appendix. Implementation of the 1997 PM NAAQS:
2.5
Timeline and Delays
Because of legal challenges, the lack of a national monitoring network, and
other factors, implementation of the 1997 PM NAAQS has been delayed since it
2.5
was promulgated. The timeline presented in Table 2 below reflects the most recent
key milestone dates for implementing the 1997 PM NAAQS, including actual
2.5
completions. These milestones are driven primarily by statutory requirements. It
follows an EPA milestone schedule outlined in an April 21, 2003, memorandum to
EPA regional administrators that also provided the nonbinding guidance for
implementation of the PM area designations.109 Recognizing potential efficiencies
2.5
associated with states and tribes being able to harmonize control strategies, the initial
PM schedule was intended to be similar to that for the eight-hour ozone program.
2.5
Table 2. Schedule for Implementation of the 1997 PM NAAQS
2.5
Date
1997 PM NAAQS Milestones
2.5
February 2004 (completed)
State-tribal area designation recommendations
(based on 2000-2002 monitoring data)
June-July 2004 (completed)
EPA notifies states and tribes regarding
modifications to their recommendations
January 5, 2005 (completed)
EPA promulgates final area designations
(70 Federal Register 944)
(required one year after states and tribes make
recommendations)
February 2005 (completed November
EPA proposes PM implementation rule
2.5
1, 2005) (70 Federal Register 65984)
April 5, 2006 (one year after the final
States with new transportation projects submit
designation April 5, 2005 effective
conformity determination within one year of the
date)
effective date of nonattainment designation
Mid-2007 (completed April 25, 2007)
EPA promulgates final PM implementation rule
2.5
April 2008 (ongoing; 3 years after
States and tribes submit revised implementation
final area designations effective date)
plans (SIPs) to achieve PM compliance in
2.5
nonattainment areas
April 2010-2015 (5-10 years after final
NAAQS statutory compliance deadline for
area designations effective date)
attainment
Source: Prepared by the Congressional Research Service based on U.S. Environmental Protection
Agency fact sheets and guidance documents, and relevant Federal Register notices.
The PM NAAQS requirement for three years of monitoring data to determine
2.5
whether areas were meeting the established limits was one factor responsible for
109 EPA memorandum, April 21, 2003, from the Office of Air and Radiation Assistant
Administrator Jeffrey R. Holmstead to EPA Regional Administrators, available at
[http://www.epa.gov/ttn/naaqs/pm/pm25_guide.html].

CRS-27
delaying implementation. Comprehensive monitoring data sufficient to make this
determination and the attainment designations were not available in 1997.
Recognizing this dilemma, in the 1998 Transportation Equity Act for the 21st Century
(TEA-21; P.L. 105-178, Title VI), Congress revised the statutory deadline
requirements for the new NAAQS, predicated on a previously released EPA Interim
Implementation Policy. TEA-21 required states to submit designation
recommendations within one year after receipt of three years of data meeting defined
federal protocols, and required EPA to promulgate designations within one year after
state recommendations were due, but not later than December 31, 2005.
As discussed earlier in this report, operation of the network of monitors was
phased in from 1999 through 2000, making three-year monitoring data available at
different points, depending on area location. Rather than a staggered designation
schedule, which would likely have resulted in hampering cross-coordination of
implementation plans, EPA proposed a single date for state and tribal
recommendations and final EPA designations. The deadlines of February 15, 2004,
for governors to submit their PM designation recommendations and December 31,
2.5
2004, for EPA to promulgate designations for each state, were the result of Congress
amending the CAA in the FY2004 omnibus appropriations (P.L. 108-199).
In addition to the delay in establishing a monitoring network, the 1997 NAAQS
standards were challenged in District Court by the American Trucking Associations,
the U.S. Chamber of Commerce, and several other state and business groups. An
initial May 1999 opinion by the District Court partially in favor of the plaintiffs was
reversed by the Supreme Court in February 2001.110
110 United States Court of Appeals for the District of Columbia Circuit, argued December
17, 1998; decided May 14, 1999 (No. 97-1440). American Trucking Associations, Inc., et
al., Petitioners v. United States Environmental Protection Agency; Whitman v. American
Trucking Associations, U.S. Supreme Court, No. 99-1257 and No. 99-1426, February 27,
2001 (121 S. Ct. 903). See CRS Report RS20860, The Supreme Court Upholds EPA
Standard Setting Under the Clean Air Act: Whitman v. American Trucking Associations
, by
Robert Meltz and James E. McCarthy.