2006 National Ambient Air Quality Standards
(NAAQS) for Fine Particulate Matter (PM2.5):
Designating Nonattainment Areas
Robert Esworthy
Specialist in Environmental Policy
September 7, 2010
Congressional Research Service
7-5700
www.crs.gov
R40096
CRS Report for Congress
P
repared for Members and Committees of Congress
2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Summary
The Environmental Protection Agency (EPA) published its final revisions to the National
Ambient Air Quality Standards (NAAQS) for particulate matter (particulates, or PM) on October
17, 2006. EPA’s actions leading up to and following promulgation of the 2006 standard have been
the subject of considerable congressional oversight. EPA and states’ ongoing implementation of
the standard, beginning with the designation of those geographical areas not in compliance,
likewise has been an area of concern and debate among some Members of Congress, states, and
other stakeholders for some time. EPA’s more recent initiation of the next round of periodic
review of the particulates NAAQS, and speculation as to the degree of stringency of any new
standards, has prompted further scrutiny of the ongoing implementation. EPA is due to propose
revised standards in February 2011 and promulgate them by October 2011.
Promulgation of NAAQS sets in motion a process under which the states and EPA identify areas
that exceed the standard (“nonattainment areas”) using multi-year air quality monitoring data and
other criteria, requiring states to take steps to reduce pollutant concentrations in order to achieve
it. On November 13, 2009, EPA published its final designations for the 2006 PM NAAQS that
include 120 counties and portions of counties in 18 states as nonattainment areas based on 2006
through 2008 air quality monitoring data. The final designations, which include tribal land of 22
tribes, were effective as of December 14, 2009. States have three years from the effective date to
submit State Implementation Plans (SIPs), which identify specific regulations and emission
control requirements that would bring an area into compliance.
In December of 2008 EPA had identified 211 counties and portions of counties (58 areas) in 25
states for designation as nonattainment for the 2006 PM NAAQS based on 2005 through 2007
data. The publication of these designations—and thus the effective date of the final
designations—was delayed pending review by the current Administration. This review and the
availability of more current air quality monitoring data resulted in the final designations
published in November 2009.
The 2006 NAAQS strengthened the pre-existing (1997) standard for “fine” particulate matter 2.5
micrometers or less in diameter (PM2.5) by lowering the allowable daily concentration of PM2.5 in
the air. The daily standard averaged over 24-hour periods is reduced from 65 micrograms per
cubic meter (µg/m3) to 35 µg/m3. However, the annual PM2.5 standard, which addresses human
health effects from chronic exposures to the pollutants, is unchanged from the 1997 standard of
15 µg/m3. The 2006 NAAQS did not substantially modify the daily standard for slightly larger,
but still inhalable, particles less than or equal to 10 micrometers (PM10), retaining the 24-hour
standard but revoking the annual standard for PM10.
EPA’s final nonattainment designations are only for the revised 2006 24-hour PM2.5 standard.
EPA did not require new nonattainment designations for PM10. The final designations for the 2006
PM2.5 NAAQS include a few areas designated nonattainment for PM2.5 for the first time, but, as
expected, the majority of the counties identified overlap with EPA’s final nonattainment
designations for the 1997 PM2.5 NAAQS. EPA’s designations for the 1997 PM2.5 NAAQS
included all or part of 204 counties in 20 states and the District of Columbia. Most of them were
only exceeding the annual standard; only 12 counties were exceeding both the 24-hour and the
annual standards. Thus, the 2006 tightening of the 24-hour standard resulted in an increased
number of areas being designated nonattainment based on exceedances of both the 24-hour and
the annual standards.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Contents
Introduction ................................................................................................................................ 1
EPA’s 2006 Changes to the Particulates NAAQS ......................................................................... 3
Designation of Geographical Nonattainment Areas...................................................................... 4
NAAQS Designation Process ................................................................................................ 4
PM2.5 NAAQS Designations.................................................................................................. 5
Comparing the 2006 and 1997 PM2.5 NAAQS Designations .................................................. 9
Demonstrating Attainment with the 2006 PM2.5 NAAQS ........................................................... 13
State Implementation Plans (SIPs)....................................................................................... 13
EPA NAAQS Implementation Rules.............................................................................. 15
National Regulations..................................................................................................... 15
New Source Review...................................................................................................... 17
Transportation Conformity ............................................................................................ 18
Conclusions .............................................................................................................................. 18
Figures
Figure 1. Counties in Nonattainment for the 2006 PM2.5 NAAQS: EPA’s November 13,
2009, Final Designations .......................................................................................................... 7
Figure 2. EPA Final Designated Nonattainment Areas for the 1997 PM2.5 Standards .................. 10
Figure 3. Counties Designated Nonattainment for the 2006 PM2.5 NAAQS................................ 12
Figure D-1. Counties in Nonattainment for the 2006 PM2.5 NAAQS: EPA’s Designations
as of December 22, 2008........................................................................................................ 34
Tables
Table 1. Counties Designated Nonattainment for the 1997 PM2.5 NAAQS and
Nonattainment for the 2006 PM2.5 NAAQS ............................................................................ 11
Table A-1. Schedule for Implementation of the 1997 and the 2006 PM2.5 NAAQS ..................... 21
Table B-1. Nonattainment Areas for the 2006 PM2.5 NAAQS as Identified by EPA in the
October 8, 2009, Final Designations and in the December 28, 2008, Status Table, and
Final Nonattainment Designations for the 1997 PM2.5 NAAQS .............................................. 22
Table C-1. EPA’s October 8, 2009, Geographic Designations for 2006 PM NAAQS:
Tribes in 24-Hour PM2.5 Nonattainment Areas ........................................................................ 33
Appendixes
Appendix A. Comparative Timeline for Implementing the 1997 and 2006 PM2.5 NAAQS.......... 21
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Appendix B. Comparison of Final and Interim Nonattainment Designation Areas for the
2006 PM2.5 NAAQS and the Final Nonattainment Designation Areas for the 1997 PM2.5
NAAQS ................................................................................................................................. 22
Appendix C. Tribal Lands: Designations for the 2006 PM2.5 NAAQS 24-Hour Standard............ 33
Appendix D. Map Depicting Counties in Nonattainment for the 2006 PM2.5 NAAQS:
EPA’s Designation as of December 22, 2008 .......................................................................... 34
Contacts
Author Contact Information ...................................................................................................... 35
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Introduction
Under Sections 108-109 of the Clean Air Act (CAA), Congress mandated that the Environmental
Protection Agency (EPA) set national ambient (outdoor) air quality standards (or NAAQS) for
pollutants whose emissions (1) “may reasonably be anticipated to endanger public health or
welfare”; and (2) “the presence of which in the ambient air results from numerous or diverse
mobile or stationary sources.” The statute further requires that EPA review the latest scientific
studies and either reaffirm or modify previously established NAAQS every five years. EPA has
identified and promulgated NAAQS for six principal pollutants commonly referred to as “criteria
pollutants”: particulate matter (PM), ozone (O3, a key measure of smog), nitrogen dioxide (NO2,
or, inclusively, nitrogen oxides,1 or NOx), sulfur oxides (SOx, or, specifically, SO2), carbon
monoxide (CO), and lead (Pb).
On October 17, 2006, EPA published its revisions to the NAAQS for particulate matter (PM) to
provide protection against potential health effects associated with short- and long-term exposure
to particulates (including chronic respiratory disease and premature mortality).2 The 2006
particulates NAAQS primarily tightened the pre-existing (1997) standard for “fine” particulate
matter 2.5 micrometers or less in diameter (PM2.5).3 The standard for slightly larger, but still
inhalable, particles less than or equal to 10 micrometers (PM10) established in 19874 was not
similarly strengthened.
Establishing NAAQS does not directly limit emissions; rather, it represents the EPA
Administrator’s formal judgment regarding the level of ambient pollution that will protect public
health with an adequate margin of safety. Promulgation of NAAQS sets in motion a process
under which the states and EPA first identify geographic nonattainment areas, those areas failing
to meet the NAAQS based on monitoring and analysis of relevant air quality data. States then
have three years from the date of EPA’s final designations to submit State Implementation Plans
(SIPs), which identify specific regulations and emission control requirements that will bring an
area into compliance.5 EPA published the final designations for the 2006 PM2.5 NAAQS on
November 13, 2009.6 The final designations rule is effective December 14, 2009 (30 days from
the date of publication). The EPA final designations reflect a change from those announced by the
agency in December 22, 2008.7 The publication of final designations—and thus the effective date
of the final designations—had been delayed since January 2009 pending review by the incoming
Administration. EPA initiated review of several previous agency decisions, including those
1 The NAAQS is for NO2; nitrogen gases that are ozone precursors are referred to as NOx.
2 Federal Register 61143-61233, October 17, 2006. See also EPA’s PM Regulatory Actions website at http://epa.gov/
pm/actions.html.
3 Federal Register 38652-38896, July 18, 1997. See CRS Report RL32431, Particulate Matter (PM2.5): Implementation
of the 1997 National Ambient Air Quality Standards (NAAQS), by Robert Esworthy.
4 Federal Register 24634-24715, July 1, 1987.
5 See EPA’s guidance, “Area Designations for 2006 24-Hour PM2.5 NAAQS - Technical Information,” at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.
6 74 Federal Register 58688-58781, November 13, 2009; see also “Area Designations for 2006 24-Hour Fine
Particulate (PM2.5) Standards—Regulatory Actions” at http://www.epa.gov/pmdesignations/2006standards/regs.htm#4.
7 See “Area Designations for 2006 24-Hour Fine Particulate (PM2.5) Standards—December 2008 Area Status (Not
Final Designations)” at http://www.epa.gov/pmdesignations/2006standards/documents/2008-12-22/12-08table.htm.
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covered by the White House January 20, 2009, memorandum,8 and the Office of Management
and Budget’s subsequent January 21, 2009, memorandum,9 on regulatory review.
The 2006 particulates NAAQS generated national interest and debate, and oversight in Congress.
Additionally, several states and industry, agriculture, business, and public advocacy groups
petitioned the U.S. Court of Appeals for the District of Columbia Circuit, challenging certain
aspects of EPA’s revisions.10 A February 24, 2009, decision11 by the court granted the petitions in
part, denying other challenges, and remanded the standards to EPA for further consideration.
While the court did not specifically vacate the 2006 PM standards, and their implementation will
proceed, the decision and EPA’s eventual actions may prompt renewed interest in PM NAAQS
among members of Congress.12
EPA’s next round of the periodic review of the particulates NAAQS (including both PM2.5 and
PM10 ) is under way. The agency announced its intention to accelerate the review, in part in
response to the D.C. Circuit Court’s decision. EPA has targeted proposing any changes to the
standards by February 2011, and October 2011 for final standards.13 Potential risk reduction
estimates and initial staff recommendations reported in recently released draft EPA assessments14
suggest further strengthening of the particulates NAAQS. In their initial reviews of EPA’s draft
assessments, members of the CASAC agreed that the evidence calls into question the adequacy of
protection afforded by the current standards for PM2.5 and PM10.15 EPA’s draft assessments and
the issue of whether the particulates NAAQS should be strengthened or not have generated
8 Memorandum to Heads and Acting Heads of Executive Departments and Agencies from Rahm Emanuel, Assistant to
the President and Chief of Staff, regarding Regulatory Review, January 20, 2009, 74 Federal Register 4435, January
26, 2009; the memorandum is also available at http://www.whitehouse.gov/omb/assets/
information_and_regulatory_affairs/regulatory_review_012009.pdf.
9 Memorandum to Heads and Acting Heads of Executive Departments and Agencies from Peter R. Orszag, Director,
Office of Management and Budget, regarding Implementation of Memorandum Concerning Regulatory Review,
January 21, 2009, http://www.whitehouse.gov/omb/assets/agencyinformation_memoranda_2009_pdf/m09-08.pdf.
10 Cases were consolidated with American Farm Bureau Federation v. U.S. EPA, 2009 Westlaw 437050, No. 06-1410
(D.C. Cir. 2006).
11 American Farm Bureau Federation v. U.S. EPA, No. 06-1410 (D.C. Cir., February 24, 2009).
12 For background on the process used to establish the 2006 particulates NAAQS and analysis of associated issues,
including the D.C. Circuit’s February 2009 decision, see CRS Report RL34762, The National Ambient Air Quality
Standards (NAAQS) for Particulate Matter (PM): EPA’s 2006 Revisions and Associated Issues, by Robert Esworthy
and James E. McCarthy.
13 P. 45220 of EPA Proposed Rule: Federal Implementation Plans to Reduce Interstate Transport of Fine Particulate
Matter and Ozone, or “Proposed Transport Rule,” as published in 75 Federal Register 45210-45465, August 2, 2010.
14 See Policy Assessment for the Review of the PM NAAQS - First External Review Draft (EPA 452/P-10-003, March
2010) and Policy Assessment for the Review of the PM NAAQS - Second External Review Draft (EPA-452/P-10-007,
June 2010) available at http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_2007_pa.html. U.S. EPA, Integrated Science
Assessment for Particulate Matter (Final Report) (EPA/600/R-08/139F, December 2009), and Risk Assessment to
Support the Review of the PM Primary National Ambient Air Quality Standards—External Review Draft (EPA
450/P_09-006, September 2009); 74 Federal Register 46589-46591, September 10, 2009. Both assessments are
available at http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_2007_fr.html.
15 EPA Clean Air Science Advisory Committee (CASAC) Particulate Matter (PM) Review Committee: CASAC Review
of Policy Assessment for the Review of the PM NAAQS – Second External Review Draft (June 2010), August 10, 2010,
Draft, http://yosemite.epa.gov/sab/sabproduct.nsf/WebCASAC/AD891A65C35DC3738525777B005B0A6F/$File/
PM+PA-2+letter+8-10-10.pdf; CASAC Review of Policy Assessment for the Review of the PM NAAQS - First External
Review Draft (March 2010), May 17, 2010, E504EE3276D87A9E8525772700647AFB/$File/EPA-CASAC-10-011-
unsigned.pdf. See also CASAC’s Review of Quantitative Health Risk Assessment for Particulate Matter – Second
External Review Draft, (February 2010), April 15, 2010, http://yosemite.epa.gov/sab/sabproduct.nsf/WebCASAC/
recent additions.
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considerable comment and debate, and prompted increased scrutiny of the EPA and states’
implementation of the 2006 PM2.5 NAAQS.
This report focuses primarily on the NAAQS implementation process for designating
geographical nonattainment areas with respect to the tightening of the PM2.5 standards under the
2006 particulates NAAQS, including comparisons with the final designations under the 1997
PM2.5 NAAQS. EPA is not requiring new nonattainment designations for PM10 based on the 2006
revisions to the standard. Also included is a brief overview of states’ subsequent obligations for
developing and submitting implementation plans (SIPs) for attaining or maintaining compliance
with the NAAQS. Appendix A contains a comparative timeline for implementing the 2006 and
1997 PM2.5 NAAQS. Appendix B provides a state and county breakdown of EPA’s November 13,
2009, final designated nonattainment areas and areas indentified by EPA on December 22, 2008,
proposed by the states for the 2006 PM2.5 NAAQS, as well as the final EPA nonattainment
designations for the 1997 PM2.5 NAAQS. Appendix C identifies tribes included in EPA’s final
nonattainment designations 2006 PM2.5 NAAQS.
EPA’s 2006 Changes to the Particulates NAAQS
The Clean Air Act provides for two types of NAAQS: primary standards, “the attainment and
maintenance of which in the judgment of the [EPA] Administrator ... are requisite to protect the
public health,” with “an adequate margin of safety”; and secondary standards, necessary to
protect public welfare, a broad term that includes visibility impairment as well as damage to
crops, vegetation, property, building materials, etc.16
The primary NAAQS include a daily (24-hour) limit for both PM2.5 and PM10, and an annual
limit for PM2.5 (the previous annual limit for PM10 was revoked). To attain the annual standard,
the three-year average of the weighted annual arithmetic mean PM concentration at each monitor
within an area must not exceed the maximum limit set by the agency. The 24-hour standards are a
concentration-based percentile form, indicating the percentage of the time that a monitoring
station can exceed the standard. For example, a 98th percentile 24-hour standard indicates that a
monitoring station can exceed the standard 2% of the days during the year. For PM2.5 and PM10,
the secondary (welfare) NAAQS are the same as the primary standards.
As modified and published in the October 17, 2006, Federal Register Notice, the primary PM2.5
and PM10 standards are as follows:
• PM2.5: strengthened the daily (24-hour) standard, which had allowed no more
than 65 micrograms per cubic meter (µg/m3) under the 1997 PM2.5 NAAQS, by
setting a new limit of 35 µg/m3, based on the three-year average of the 98th
percentile of 24-hour PM2.5 concentrations; retained the annual standard at 15
µg/m3.
• PM10: retained the daily standard at 150 µg/m3 set in 1987 but changed from the
99th percentile to no more than one exceedance per year on average over three
16 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)).
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years; eliminated the annual maximum concentration (50 µg/m3) standard for
PM10.17
As will be shown in more detail in the following section, strengthening the daily standard for
PM2.5 has implications for those counties and partial counties designated nonattainment for the
1997 PM2.5 NAAQS. With only a few exceptions, most of the designated nonattainment areas for
the 1997 PM2.5 NAAQS were not meeting the annual standard, but were meeting the daily (24-
hour) standard. EPA is not requiring new nonattainment designations for PM10 since the
standards were not strengthened. To the contrary, a few counties previously designated
nonattainment for PM10 have been determined by EPA to be in attainment since the 2006 revisions
to the particulates NAAQS were promulgated.18
Designation of Geographical Nonattainment Areas
Designating geographical areas not achieving the established NAAQS based on monitoring and
analysis of relevant air quality data, is a critical step in NAAQS implementation. Section 107(d)
of the CAA (42 U.S.C. 7407) establishes the process for designating attainment and
nonattainment areas and setting their boundaries, but 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.
NAAQS Designation Process
The NAAQS designation process is intended as a cooperative federal-state-tribal19 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). Areas are identified as “attainment/unclassified”20 when they
meet the standard or when the data are insufficient for determining compliance with the NAAQS.
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
17 Based on findings in the EPA PM criteria document and staff paper, and the CASAC’s concurrence, that the studies
reviewed do not provide sufficient evidence regarding long-term exposure to warrant continuation of an annual
standard, see 71 Federal Register 2653, Section III. Rationale for Proposed Decision on Primary PM10 Standards,
January 17, 2006.
18 See discussion and map in Appendix A depicting PM10 nonattainment areas, in CRS Report RL34762, The National
Ambient Air Quality Standards (NAAQS) for Particulate Matter (PM): EPA’s 2006 Revisions and Associated Issues, by
Robert Esworthy and James E. McCarthy.
19 Though not required, 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 PM2.5 designation recommendation process, see http://www.epa.gov/pmdesignations.
20 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.
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opportunity to demonstrate why a proposed modification is inappropriate, but the final
determination rests with EPA.
Measuring and analyzing air quality to determine where NAAQS are not being met is a key step
in determining an area’s designation. Attainment or nonattainment designations are made
primarily on the basis of three years of federally referenced monitoring data.21 EPA began
developing methods for monitoring fine particles at the time the PM2.5 NAAQS were being
finalized in 1997, and operation of the network of monitors for PM2.5 was phased in from 1999
through 2000.
The network of monitors and their locations have been modified over time. Most recently, in a
separate action in conjunction with the October 2006 publication of the revised particulates
NAAQS, EPA amended its national air quality monitoring requirements, including those for
monitoring particle pollution.22 The amended monitoring requirements were intended to help
federal, state, and local air quality agencies by adopting improvements in monitoring technology.
EPA’s final designations for the 2006 PM2.5 NAAQS published November 13, 2009, are based on
air quality monitoring data for calendar years 2006 through 2008.
In addition to air emission and air quality data, EPA considers a number of other relevant
factors,23 and recommends that states apply these factors in their determinations in conjunction
with other technical guidance. Examples of these factors include population density and degree of
urbanization (including commercial development), growth rates, traffic and commuting patterns,
weather and transport patterns, and geography/topography. States and tribes may submit
additional information on factors they believe are relevant for EPA to consider.
Nonattainment areas include those counties where pollutant concentrations exceed the standard as
well as those that contribute to exceedance of the standard in adjoining counties. Entire
metropolitan areas tend to be designated nonattainment, even if only one county in the area has
readings worse than the standard. In addition to identifying whether monitored violations are
occurring, states’ or tribes’ boundary recommendations for an area are to also show that violations
are not occurring in those portions of the recommended area that have been excluded, and that
they do not contain emission sources that contribute to the observed violations.
PM2.5 NAAQS Designations24
On November 13, 2009, EPA published its final designations of 31 areas in 18 states, comprising
120 counties (89 counties and portions of 31 additional counties) for nonattainment of the revised
2006 24-hour PM2.5 standard.25 (See Table B-1 in Appendix B for state-by-state county/area
21 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).
22 Revisions to Ambient Air Monitoring Regulations, final rule, 71 Federal Register 61235-61328, October 17, 2006.
http://www.epa.gov/air/particlepollution/actions.html.
23 See Chapter 5 of the EPA Technical Support Document for December 17, 2004, final designations for the 1997
PM2.5 NAAQS and April 2005 modifications, for explanations of these factors; available at http://www.epa.gov/
pmdesignations/1997standards/tech.htm.
24 For detailed PM2.5 state/county geographical designation recommendations by EPA and those from individual states
and tribes, for the 1997 and for the 2006 PM2.5 NAAQS, see http://www.epa.gov/pmdesignations.
25 See footnote 6.
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nonattainment designations). The counties (and partial counties) that EPA designated as
nonattainment for the 2006 PM2.5 NAAQS are indicated in the map in Figure 1. The map
distinguishes those counties not previously designated nonattainment for the PM2.5 NAAQS and
those areas that are being designated for the 2006 PM2.5 24-hour standard, that were previously
designated nonattainment for the 1997 PM2.5 NAAQS.
EPA’s November 2009 final designations, which are based on air quality monitoring data for
calendar years 2006 through 2008, do not include counties violating the annual standard, as the
level is unchanged from the 1997 PM2.5 NAAQS. As with the designations for the 1997 PM2.5 and
other criteria pollutant NAAQS standards, several areas include counties from multiple states.
EPA also included portions of tribal lands of 22 tribes in areas designated nonattainment (see
Appendix C for list of tribes included in the final 2006 24-hour PM2.5 NAAQS nonattainment
areas).
EPA’s final designations differ from those identified by the agency on December 22, 2008, based
on air quality monitoring data for calendar years 2005 through 2007. At that time, EPA had
identified 58 areas in 25 states, comprising 211 counties (154 counties and portions of 57
additional counties) for designation as nonattainment of the revised 2006 24-hour PM2.5
standard26 (see Table B-1 in Appendix B for a comparison of the state-by-state county/area
nonattainment designations; counties (and partial counties) designated as nonattainment for the
2006 PM2.5 NAAQS as of December 22, 2008, are indicated on the map in Figure D-1 of
Appendix D).
Publication of a final designation rule for the 2006 PM2.5 NAAQS was delayed pending review by
the agency under the current Administration. The review of the final designation rule, along with
several other agency proposed and final actions introduced toward the end of the previous
Administration, was initiated, in part, in response to a White House January 20, 2009,
memorandum,27 and the Office of Management and Budget’s subsequent January 21, 2009,
memorandum,28 regarding regulatory review. During this review, EPA revised its designations
based on more current monitoring data (calendar years 2006-2008).
Delaying publication of the final designation rule resulted in the delay of the expected effective
date, which had been scheduled for April 2009.29 The effective date of the final designations rule
is December 14, 2009 (30 days from the date of publication).
26 See EPA’s “Area Designations for 2006 24-Hour Fine Particulate (PM2.5) Standards—December 2008 Area Status
(Not Final Designations),” http://www.epa.gov/pmdesignations/2006standards/documents/2008-12-22/12-08table.htm.
27 See footnote 8.
28 See footnote 9.
29 See EPA’s guidance, “Area Designations for 2006 24-Hour PM2.5 NAAQS - Technical Information,” at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.
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Figure 1. Counties in Nonattainment for the 2006 PM2.5 NAAQS: EPA’s November 13, 2009, Final Designations
(violating the 24-hour standard (35 μg/m3) only)
Source: Prepared by the Congressional Research Service with data obtained from EPA based on EPA’s final designations for the 2006 PM2.5
NAAQS. See U.S. EPA, “40 CFR Part 81 Air Quality Designations for the 2006 24-Hour Fine Particle (PM2.5) National Ambient Air Quality
Standards; Final Rule, 74 Federal Register 58687, November 13, 2009.
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The majority of U.S. counties (including partial counties and tribal lands) were designated
attainment/unclassifiable. While the final number of nonattainment areas and associated counties
can seem small compared with the approximately 3,000 counties throughout the United States,
nonattainment counties tend to have larger populations than those in attainment: for example,
more than 70 million people (just less than 25% of the U.S. population30) live in the 120 counties
designated nonattainment for the 2006 PM2.5 NAAQS.
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)). However, unlike the 1997 PM2.5
standards, Metropolitan Statistical Areas or Consolidated Metropolitan Statistical Areas31 did not
generally serve as the “presumptive boundary” for nonattainment areas under the 2006 PM2.5
standards. Rather than establish a presumption for the minimum size of an area, in its June 2007
guidance32 EPA instructed states and tribes to evaluate each area on a case-by-case basis. EPA
expected that nonattainment areas for the 2006 24-hour PM2.5 would include counties with
monitors violating the 24-hour standard and nearby counties that contribute to that violation. EPA
also recommended that states and tribes consider using common boundaries for areas to be
designated as nonattainment for both the annual and 24-hour PM2.5 standards. This information in
conjunction with air emission and air quality data, as well other relevant factors as recommended
in EPA’s guidance, such as population density, growth rates, traffic and commuting patterns,
weather and transport patterns, and geography/topography, were used by states in determining the
boundaries for the designated areas.
By December 2007, 20 states provided EPA with recommended nonattainment boundaries for the
2006 revised particulates NAAQS based on 2004 to 2006 monitoring data. The states identified
46 areas comprising 116 counties, including 31 partial counties.33 The state-recommended
designations were primarily based on air quality monitoring data for calendar years 2004 through
2006, criteria and technical guidance from EPA and assistance from its regional offices, and
states’ own relevant information and criteria.
As required by statute, EPA responded to the states with its modifications to the area designation
recommendations for the 2006 PM2.5 NAAQS for the 24-hour standard in letters dated August 19,
2008. The agency identified 57 areas in 26 states, comprising 213 counties (167 counties and
portions of 46 additional counties) for designation as nonattainment for the revised 2006 24-hour
PM2.5 standard. EPA solicited the states’ comments and additional information for consideration
in determining the final designations.34 As it did in implementing the 1997 PM2.5 NAAQS and has
done with other NAAQS, EPA used its discretion to expand the size of nonattainment areas
(added more counties or portions of counties) or to combine areas that a state listed as separate
30 Three hundred seven million, based on U.S. Census Bureau, 2009 Population Estimates, Census 2000,
http://www.census.gov/.
31 As defined by the Office of Management Budget. For more information on metropolitan areas, see
http://www.census.gov/population/www/estimates/aboutmetro.html.
32 See EPA’s guidance at “Area Designations for 2006 24-Hour PM2.5 NAAQS - Technical Information,”
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.
33 For detailed information regarding state recommendations for the 2006 PM2.5 NAAQS, see EPA’s PM Designations
website at http://www.epa.gov/pmdesignations/2006standards/state.htm.
34 For information regarding EPA’s August 19, 2008, proposed designations and responses to states, see
http://www.epa.gov/pmdesignations/2006standards/regs.htm#2.
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areas into a single larger unit, EPA also combined nonattainment counties across state lines into
the same nonattainment area, if the counties are part of the same metropolitan area.
States (and tribal groups) had 120 days to respond to EPA’s recommendations, and the agency
also issued a notice35 for a 30-day public comment period. As occurred with EPA’s proposed
nonattainment designations for the 1997 PM2.5 NAAQS,36 several states challenged the agency
and maintained support for their original recommendations in response to the agency’s proposed
nonattainment areas for the 2006 PM2.5 NAAQS. EPA designations for the 2006 PM2.5 NAAQS as
of December 22, 2008, based on 2005 through 2007 air monitoring data reflected minor
modifications to those proposed; primarily, two 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.37
As discussed previously in this report, the November 13, 2009, final designations for the 2006
PM2.5 NAAQS based on 2006 through 2008 monitoring data resulted in fewer nonattainment
areas/counties than EPA had proposed in August 2008 and identified as of December 2008 (Table
B-1 in Appendix B includes a state-by-state comparison of EPA’s final county/area
nonattainment designations with the agency’s designations as of December 22, 2008). EPA’s final
designations for the 2006 PM2.5 NAAQS published in November 2009 included 27 fewer
nonattainment counties than identified as of December 2008, 26 fewer areas than proposed in
August 2008, and 17 fewer areas than recommended by the states. EPA’s final nonattainment
designation areas included 7 fewer states and 91 fewer counties than identified as of December
2008, 7 fewer states and 95 fewer counties than proposed, and 3 fewer states and 27 fewer
counties than recommended by the states.38
Comparing the 2006 and 1997 PM2.5 NAAQS Designations
EPA’s final designations for nonattainment of the 1997 PM2.5 NAAQS (those areas with or
contributing to air quality levels exceeding the annual and 24-hour standards) included all or part
of 204 counties in 20 states and the District of Columbia.39 As indicated in the map in Figure 2,
below, the designated nonattainment areas for the 1997 PM2.5 NAAQS are primarily concentrated
in the central, mid-Atlantic, and southeastern states east of the Mississippi River, as well as in
California. More than 2,900 counties in 30 states were designated attainment/unclassifiable for
the 1997 PM2.5 NAAQS.
35 73 Federal Register 51259-51260, September 2, 2008.
36 EPA designations for the 1997 PM2.5 NAAQS reflected minor modifications to its 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. EPA also subsequently 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 PM2.5 NAAQS. The petitions were for counties in Georgia, Illinois, Michigan, Missouri, Ohio, and West
Virginia; see http://www.epa.gov/pmdesignations/1997standards/regs.htm.
37 See EPA’s website at http://www.epa.gov/pmdesignations/2006standards/documents/2008-12-22/12-08table.htm,
which provides a table with state-by-state comparisons of designations for the 2006 PM2.5 NAAQS as recommend by
the states, proposed by EPA August 19, 2008, and as identified by EPA December 22, 2008.
38 See footnote 37.
39 See EPA’s PM2.5 Designations websites at http://www.epa.gov/pmdesignations and http://www.epa.gov/oar/oaqps/
greenbk/qnca.html. See also CRS Report RL32431, Particulate Matter (PM2.5): Implementation of the 1997 National
Ambient Air Quality Standards (NAAQS), by Robert Esworthy.
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Figure 2. EPA Final Designated Nonattainment Areas for the 1997 PM2.5 Standards
(violating the annual (15 μg/m3) and/or 24-hour (65 μg/m3) standard)
Sources: Prepared by the Congressional Research Service based on EPA’s final designations for the 1997 PM2.5 NAAQS, with data obtained from EPA.
CRS-10
2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Table 1 below illustrates the comparative geographic distribution of counties designated
nonattainment for the 2006 PM2.5 NAAQS (based on EPA’s October 8, 2009, final designations),
and those counties in EPA’s final area designations for the 1997 PM2.5 NAAQS. Based on EPA’s
October 2009 final designations for the 2006 PM2.5 NAAQS, 38 counties would be designated
nonattainment for PM2.5 for the first time but the majority of the counties identified overlap with
EPA’s final nonattainment designations for the 1997 PM2.5 NAAQS. Most of the 1997 PM2.5
nonattainment areas were only exceeding the annual standard; only 12 counties were exceeding
both the 24-hour and the annual standards. Thus, tightening the 24-hour standard resulted in an
increased number of areas (82 counties) being designated nonattainment based on exceedances of
both the 24-hour and the annual standard.
Table 1. Counties Designated Nonattainment for the 1997 PM2.5 NAAQS and
Nonattainment for the 2006 PM2.5 NAAQS
PM2.5 NAAQS (annual/24-hour μg/m3)
1997 Standard
2006 Standard
15/65 μg/m3
15/35 μg/m3
National West East National West East
Number of counties (including partial counties and D.C.)
Total exceeding the standard
204
13
191
242
43
199
Exceeding the 24-hour and annual
12 12 0 81 11 70
standards
Exceeding the 24-hour standard only
0
0
0
39
31
8
Exceeding the annual standard only
192
1
191
122
1
121
Source: Prepared by the Congressional Research Service with data compiled from EPA’s websites for PM
designations at http://www.epa.gov/pmdesignations/ and http://www.epa.gov/oar/oaqps/greenbk/qnca.html.
Nonattainment counties are based on EPA’s final designations for the 2006 PM2.5 NAAQS for the 24-hour
standard published November 13, 2009, and the final area designations for the 1997 PM2.5 NAAQS for the 24-
hour and annual standards as of July 31, 2009.
Note: The counties in the table for the 2006 standards reflect EPA’s final designations for nonattainment area
boundaries for the 2006 24-hour only PM2.5 NAAQS based on 2006-2008 air quality monitoring data, overlaid
with the final designations for the annual standards (which were unchanged) for the 1997 PM2.5 NAAQS as of July
31, 2009.
The map in Figure 3, below, shows the overlap of the final nonattainment designations for the
24-hour standard, as modified under the 2006 PM2.5 NAAQS, with the final designated
nonattainment areas for the annual standard under the 1997 PM2.5 NAAQS.
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Figure 3. Counties Designated Nonattainment for the 2006 PM2.5 NAAQS
(violating the annual (15 μg/m3) and/or 24-hour (65 μg/m3) standard)
Source: Prepared by the Congressional Research Service with data obtained from EPA. Nonattainment counties for the 24-hour standard are
based on EPA’s November 13, 2009, final designations for the 2006 PM2.5 NAAQS; nonattainment counties for the annual standard (which were
unchanged) are based on EPA’s final area designations for the 1997 PM2.5 NAAQS as of December 31, 2008. Partial counties are shown on the map
as whole counties.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
It is difficult to anticipate what effect the overlap of nonattainment designations may have on
current control measures in these areas. In some areas, current measures focused on achieving
attainment for the annual standard may be sufficient to attain the 24-hour standard as well. Other
areas may require supplementing current measures or significant modifications to ensure
compliance over a shorter averaging period. The impacts could vary substantially from area to
area within a state and from state to state depending on many factors, including the type and
locations of primary emission sources, current control measures, the extent to which the area is
exceeding the standard, topography, weather, etc.
Once designations take effect, they become an important component of state, local and tribal
governments’ efforts to reduce fine particle pollution. The designations govern what subsequent
regulatory actions states, tribes, and EPA must take in order to improve or preserve air quality in
each area.
Demonstrating Attainment with the 2006 PM2.5
NAAQS
Under the CAA, EPA sets the nationwide standard for criteria pollutants, and EPA and states are
responsible for placing limits on emissions that contribute to criteria pollution and for regulating
entities emitting criteria pollutants. Within three years of issuance of a NAAQS, all states are
required to submit “infrastructure” plans demonstrating that they have the basic air quality
management components necessary to implement the NAAQS.40 Areas designated
attainment/unclassifiable will not have to take steps to improve air quality but under the statute
they must take steps to prevent air quality from deteriorating to unhealthy levels. For those areas
designated nonattainment, state, local and tribal governments must outline detailed control
requirements in plans demonstrating how they will meet the 2006 PM2.5 NAAQS. These plans,
defined as state implementation plans and referred to as SIPs (TIPs for tribal implementation
plans), must be submitted to EPA three years after the effective date of the agency’s final
designations.41 If states fail to develop an adequate implementation plan, EPA can impose one.
Under CAA, states are required to meet the 2006 PM2.5 standard “as expeditiously as practicable,”
but no later than five years from the effective date of designation unless an extension allowed
under the CAA is granted.42
State Implementation Plans (SIPs)
All states are required to submit SIPs that include the basic program requirements for managing
air quality required in section 110(a)(2) of the CAA, showing that they have the capacity to attain,
40 Section 110(a)(2) of the Clean Air Act. For a general overview of the NAAQS implementation plans process, see
EPA’s “State Implementation Plan Overview” at http://www.epa.gov/air/urbanair/sipstatus/overview.html.
41 Section 172 of the Clean Air Act. See EPA’s “State Implementation Plan Overview” at http://www.epa.gov/air/
urbanair/sipstatus/overview.html.
42 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.”
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maintain, and enforce the revisions associated with the 2006 PM2.5 NAAQS. These
“infrastructure SIP” submissions must address a number of basic elements, including:
• ambient air quality monitoring and data systems;
• programs for enforcement of control measures;
• adequate authority and resources to implement the plan;
• prohibition of interstate pollution transport.
On June 9, 2010, EPA published a finding that 23 states, the District of Columbia, and five
territories had failed to submit complete “infrastructure” SIPs required within three years of
promulgation of the 2006 PM2.5 NAAQS.43 EPA’s findings notice addresses the first two of four
elements under section 110(a)(2)(D)(i) to satisfy nonattainment and transport requirements. These
two elements require each state to demonstrate adequate provisions for the ability to prohibit air
emissions within the state which: “(1) contributes significantly to another state’s nonattainment of
the NAAQS; or (2) interferes with maintenance of a NAAQS.” The findings notice initiates a
two-year deadline for EPA to promulgate a Federal Implementation Plan (FIP) unless a state
submits, and EPA approves, a plan to meet these two elements prior to the deadline.
Nonattainment area 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. SIPs must identify, among other items, specific
regulations, emissions limitations, and monitoring provisions that will bring an area into
compliance. States and local governments are required to develop and implement new or revised
plans (SIPs) for addressing emissions in those areas that do not meet the 2006 revised PM2.5
NAAQS. Nonattainment area SIPS for the 2006 PM2.5 NAAQS are required to be submitted to
EPA for review and approval by December 2012, three years from the effective date of the final
designations. As previously indicated, the effective date of the final designations rule is
December 14, 2009 (30 days from the date of publication).
Several counties designated as nonattainment for the PM2.5 NAAQS are designated for the first
time. As noted earlier, a large portion of the nonattainment areas for the 2006 PM2.5 NAAQS
designated by EPA November 2009, overlap with those areas designated nonattainment for the
1997 PM2.5 NAAQS. However, as discussed in the previous section, these areas are now unable to
meet the 24-hour standard, whereas previously many of them were designated nonattainment
based on their inability to meet the annual standard. Exceeding both an annual and 24-hour
standard may have implications with respect to existing SIPs, the extent of which could vary
significantly from area to area based on many factors. In some cases SIPs may require substantial
modifications, while in other cases the current SIP may be sufficient to achieve compliance with
both standards.
In a February 2006 advance notice of proposed rulemaking (ANPR)44 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 PM2.5 NAAQS when developing their strategies for the 1997 PM2.5 standards.
43 75 Federal Register 32673-32676, June 9, 2010.
44 71 Federal Register 6718, February 9, 2006.
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EPA NAAQS Implementation Rules
EPA typically publishes an “implementation rule” which describes the requirements that states
and tribes must meet in their implementation plans to achieve and maintain attainment.45 The rule
also provides guidance and procedures for establishing controls to achieve and maintain
attainment. In addition to detailing provisions necessary to demonstrate how the 2006 PM2.5
NAAQS will be attained, the implementation rule generally includes guidance for submitting a
SIP when reaching attainment within the five-year requirement is impractical. The
implementation rule takes into account existing (oft times pending) federal regulations that
contribute to controlling criteria pollutants and their precursors.46
The basic framework of the current implementation rule for the 1997 PM2.5 NAAQS provides
guidance for implementation of the 2006 standards. EPA plans to revise the regulatory text of the
implementation rule to change certain provisions that refer specifically to the 1997 PM2.5
standards to more generic language that would apply also to the 2006 standards and to future
revisions of the PM2.5 NAAQS as well, by the end of 2011.47
National Regulations
EPA expects that in many cases implementing national strategies—including the 1999 visibility
protection regulations (Regional Haze Rule);48 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 PM2.5 NAAQS. However, one of the key federal regulations, EPA’s May 2005 Clean Air
Interstate Rule (CAIR),49 was vacated in a July 11, 2008, decision (North Carolina v. EPA), by the
U.S. Court of Appeals for the D.C. Circuit.50 The D.C. Circuit subsequently modified its decision
on December 23, 2008,51 in response to an EPA motion,52 reversing its decision to vacate CAIR
while EPA developed a replacement rule. The Circuit, however, left the substantive requirements
of its July 2008 decision fully intact. That decision strongly suggests that there is no simple “fix”
45 EPA published its final implementation rule for the 1997 PM2.5 NAAQS On April 25, 2007. 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 (72 Federal Register 20586-20667, April 25, 2007).
46 The term precursor refers to a directly emitted pollutant that, when released to the atmosphere, forms, or contributes
to the formation of a secondary pollutant for which an ambient air quality standard has been adopted.
47 Information provided to CRS by EPA’s Office of Air Quality and Planning, August 26, 2010.
48 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.
49 Promulgated under the CAA, 42 U.S.C. 7401 et seq., 70 Federal Register 25162, May 12, 2005.
50 531 F.3d 896 (D.C. Cir. 2008), see CRS Report RL34589, Clean Air After the CAIR Decision: Multi-Pollutant
Approaches to Controlling Powerplant Emissions, by James E. McCarthy, Larry Parker, and Robert Meltz; also see
EPA Clean Air Interstate Rule website at http://www.epa.gov/CAIR/index.html.
51 550 F.3d 1176 (D.C. Cir. 2008).
52 EPA requested reconsideration on September 24, 2008, with suggestion for rehearing by the entire court.
Alternatively, EPA requested that the CAIR rule be allowed to continue in effect while the agency developed a
replacement program that satisfied the court’s July 2008 decision. The Natural Resources Defense Council (NRDC),
the National Mining Association, and the Utility Air Regulatory Group also petitioned the court for a rehearing.
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that would make CAIR acceptable to the court. The court’s decision to vacate the rule drew the
interest of some Members of Congress and was the subject of a July 29, 2008, congressional
hearing.53
EPA’s May 2005 CAIR was expected to serve as the primary tool to assist downwind states in
meeting the PM2.5 (and eight-hour ozone) NAAQS by mitigating interstate transport of sulfur
dioxide (SO2) and nitrogen oxide (NOx) emissions from electric generating units that contribute
to the formation of PM2.5.54 CAIR covered 28 states in the eastern United States and the District
of Columbia, including 26 jurisdictions in the PM2.5 nonattainment region. As a preferred
implementation strategy, EPA encouraged states to use a trading program to reduce emissions of
target pollutants by up to 70% in a cost-effective manner.55 Without CAIR, most eastern states
would have a huge gap in their emission control programs.
On August 2, 2010, EPA published a proposed “Transport Rule” intended to supersede the current
CAIR.56 The proposed rule would limit sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions
from electric generating units within 31 states in the eastern United States and the District of
Columbia that affect the ability of downwind states to attain and maintain compliance with the
1997 and 2006 PM2.5 and the 1997 ozone NAAQS. The proposal includes modifications in
response to the Court’s concerns, particularly with regard to certain aspects of emissions
contributing to ozone.57 The implications of this proposal have already generated considerable
debate among states, industry, and other stakeholders, and have been the topic of further
deliberation by Congress. The Senate Committee on Environment and Public Works
Subcommittee on Clean Air and Nuclear Safety held a hearing on EPA’s proposed alternative
transport rule on July 22, 2010.58 EPA scheduled three public hearings,59 and comments on the
proposal must be received on or before October 1, 2010.
EPA’s development of an alternative to CAIR, and the timeliness in which it will be achieved,
raises more questions with respect to the implementation of the 2006 revised PM2.5 NAAQS. EPA
53 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/.
54 Sulfur dioxide (SO2) is a precursor (a pollutant that is transformed in air to form another air pollutant) contributing to
the formation of PM2.5, and NOx is a precursor contributing to the formation of both ozone and PM2.5. EPA has
concluded that SO2 and NOx emissions, through the phenomenon of air pollution transport, contribute significantly to
downwind nonattainment, or interfere with maintenance, of the PM2.5 and eight-hour ozone NAAQS (70 Federal
Register 25162, May 12, 2005).
55 See EPA’s CAIR website at http://www.epa.gov/airmarkets/progsregs/cair/index.html.
56 75 Federal Register 45210-45565, August 2, 2010. See also U.S. EPA, “Air Transport” website at
http://www.epa.gov/airtransport/actions.html#jul10. EPA announced the release of the proposal on July 6, 2010.
57 According to the fact sheet accompanying the proposal, EPA plans to propose a separate transport rule to address the
2010 ozone standard in 2011 (see footnote 56).
58 Senate Committee on Environment and Public Works, Subcommittee on Clean Air and Nuclear Safety, hearing,
“Oversight: EPA’s Proposal for Federal Implementation Plans to Reduce Interstate Transport of Fine Particulate Matter
and Ozone,” July 22, 2010, http://epw.senate.gov/public/index.cfm?FuseAction=Hearings.Home. EPA announced the
release of the “Air Transport Rule” on July 6, 2010, but it was not published in the Federal Register until August 2,
2010.
59 The public hearings were held Thursday, August 19, 2010, in Chicago, Illinois, on Thursday, August 26, 2010, in
Philadelphia, Pennsylvania, and on Wednesday, September 1, 2010, in Atlanta, Georgia, 75 Federal Register 45075-
45076, August 2, 2010.
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anticipates finalizing the proposed “Transport Rule” published August 2, 2010,60 by late spring
2011. In the interim, according to EPA, current CAIR requirements for reductions remain in
effect, and CAIR regional control programs continue their operations pending the agency’s
promulgation of an alternative transport rule.61
New Source Review62
Designated nonattainment areas also are subject to new source review (NSR) requirements.
Enacted as part of the 1977 CAA Amendments and modified in the 1990 CAA Amendments,
NSR is designed to ensure that newly constructed facilities, or substantially modified existing
facilities, do not result in violation of applicable air quality standards. NSR provisions outline
permitting requirements both for construction of new major pollution sources and for
modifications to existing major pollution sources. The specific NSR requirements for affected
sources depend on whether the sources are subject to Prevention of Significant Deterioration
(PSD) or nonattainment provisions.63
EPA promulgated a rule in May 200864 that contained several NSR program requirements for
sources that emit PM2.5 and the pollutants that contribute to its formation (precursors), including
SIPS modifications to state NSR programs to account for emissions of PM2.5. On February 11,
2010, EPA proposed65 to repeal a portion of that rule implementing the NSR permitting program
for PM2.5, known as “the grandfathering provision,” in part in response to petitions66 to reconsider
the May 2008 final rule. The provision allowed applicants for federal “Prevention of Significant
Deterioration” (PSD) permits to rely on requirements for coarse particles (PM10) as a surrogate
for meeting the permit requirements for PM2.5 if they applied for, and were awaiting approval for,
a permit before July 15, 2008. The EPA proposal also would end the PM10 Surrogate Policy in
place since 1987, sooner than currently scheduled. The policy enables sources to make a
demonstration of compliance with PSD requirements for PM10 as a surrogate for requirements for
PM2.5 in light of various technical issues associated with undertaking a PM2.5 analysis, which EPA
has now determined have generally been resolved. Presently, states with EPA-approved PSD
programs may use the surrogate policy until May 2011, or until EPA approves the revised State
Implementation Plan (SIP) for PM2.5.
60 75 Federal Register 45210-45565, August 2, 2010. See also U.S. EPA “Air Transport” at http://www.epa.gov/
airtransport/actions.html#jul10. EPA announced the release of the proposal on July 6, 2010.
61 EPA proposed Transport Rule fact sheet, p. 5, available at http://www.epa.gov/airtransport/actions.html.
62 For an overview, including statutory authority and regulations, see EPA’s “New Source Review (NSR)” at
http://www.epa.gov/air/nsr/.
63 See Clean Air Act, Part D—Plan Requirements for Nonattainment Areas, sections 171-178, codified at 40 CFR
52.24(f)(10).
64 Implementation of the New Source Review (NSR) Program for Particulate Matter Less Than 2.5 Micrometers
(PM2.5), 73 Federal Register 28321-28350, May 16, 2008.
65 “Implementation of the New Source Review NSR Program for Particulate Matter Less Than 2.5 Micrometers:
Proposed Repeal of Grandfathering Provision and End the PM10 Surrogate Policy,” 75 Federal Register 6827-6836,
February 11, 2010. See also EPA’s Fact Sheet at http://www.epa.gov/air/nsr/documents/20100204repealfs.pdf.
66 EPA Notice granting the petition to reconsider the Natural Resources Defense Council and Sierra Club to reconsider
certain provisions of the May 2008 Fine Particulates NSR Permitting final permitting rule. See EPA’s Fact Sheet at
http://www.epa.gov/air/nsr/documents/20100204repealfs.pdf.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Transportation Conformity
If new or revised SIPs for attainment establish or revise a transportation-related emissions budget,
or add or delete transportation control measures (TCMs), they will trigger “conformity”
determinations. Transportation conformity is required by the CAA, Section 176(c),67 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.
On March 24, 2010, EPA published a final rule amending the transportation conformity regulation
primarily to incorporate the October 17, 2006, strengthening of the 24-hour PM2.5 air quality
standard and revocation of the annual PM10 standard.68 The final rule, which affects
implementation of conformity in PM2.5 and PM10 nonattainment and maintenance areas, also
addresses a court remand concerning hot-spot analyses as they apply to PM2.5 and PM10, as well
as to carbon monoxide and nonattainment and maintenance areas.
Conclusions
The designation of geographical areas unable to meet the NAAQS is a critical step in NAAQS
implementation, and historically has been an issue of concern and debate among EPA, states and
tribes, various stakeholders, and some Members of Congress. EPA’s 2006 tightening of the PM2.5
standards increased the number of areas (typically defined by counties or portions of counties) in
nonattainment, and subsequently will potentially result in an encumbrance on states to achieve
compliance. A February 24, 2009, decision by the U.S. Court of Appeals for the District of
Columbia Circuit did not vacate the 2006 standards but granted petitions in part, denying other
challenges, and remanded the standards to EPA for further consideration.69 Although EPA and
states continue the implementation of the 2006 revised PM2.5 standards, the next round of periodic
review of the particulates NAAQS is under way, and EPA is due to propose revised standards in
February 2011 and promulgate them by October 2011.
Within three years of issuance of a NAAQS, all states were required to demonstrate that they
have the basic infrastructure and capacity necessary to implement the 2006 PM2.5 NAAQS. On
June 9, 2010, EPA published a finding that 23 states, the District of Columbia, and five territories
failed to submit complete “infrastructure” SIPs,70 with respect to two of four elements under
section 110(a)(2)(D)(i) to satisfy nonattainment and transport requirements. These two elements
require each state to demonstrate adequate provisions for the ability to prohibit air emissions
within the state which: “(1) contributes significantly to another state’s nonattainment of the
NAAQS; or (2) interferes with maintenance of a NAAQS.” EPA will promulgate a Federal
67 42 U.S.C. 7506(c).
68 75 Federal Register 14260, March 24, 2010. Prior to the final rule EPA provided interim guidance for meeting
conformity requirements: Interim Transportation Conformity Guidance for 2006 PM2.5 NAAQS Nonattainment Areas
(EPA-420-B-09-036, November 2009) (http://www.epa.gov/otaq/stateresources/transconf/policy/420b09036.pdf). See
also EPA’s “Transportation Conformity: Regulations” at http://www.epa.gov/otaq/stateresources/transconf/conf-
regs.htm, which provides access to all transportation conformity regulations and policy guidance.
69 American Farm Bureau Federation v. U.S. EPA, No. 06-1410 (D.C. Cir., February 24, 2009).
70 75 Federal Register at 32673-32676, June 9, 2010.
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Implementation Plan (FIP) unless a state submits, and EPA approves, a plan to meet these two
elements within two years of the Notice.
On November 13, 2009, EPA published its final designations of areas as nonattainment and
unclassifiable/attainment for the 2006 PM2.5 NAAQS. Publication of a final designation rule for
the 2006 PM2.5 NAAQS was delayed pending review by the agency as part of the
Administration’s review of several proposed and final actions introduced toward the end of the
previous Administration.71 Delaying publication of the final designation rule resulted in the delay
of the expected effective date of April 200972 to December 14, 2009 (30 days from the date of
publication).
The November 2009 final designations, based on more current monitoring data (calendar years
2006-2008), differed from those areas EPA had included in its December 22, 2008, notifications
to governors and tribal leaders and from EPA’s August 2008 proposed modifications to
nonattainment designation recommendations submitted by states. Historically, there have been
disagreements between EPA and states, and other stakeholders, with regard to final NAAQS
nonattainment designations, and questions have been raised with regard to the final designations
for the 2006 PM2.5 NAAQS.
Three years following the publication of the final designations, state, local and tribal governments
are to outline detailed control requirements in plans (or nonattainment SIPs) demonstrating how
areas designated nonattainment will meet the 2006 standards. Although a large portion of the
nonattainment areas for the 2006 PM2.5 NAAQS designated by EPA in November 2009 overlap
with those areas previously designated nonattainment for 1997 PM2.5 NAAQS, these new
designations are based on the 24-hour standard, whereas the majority of the previous designations
were based on the annual standard.
One of the key federal regulations, the May 2005 Clean Air Interstate Rule (CAIR),73 that EPA
expected would provide states a framework for achieving attainment with the PM2.5 NAAQS, was
initially vacated, then temporarily reinstated by U.S. Court of Appeals for the D.C. Circuit
decisions (North Carolina v. EPA74) in 2008. The May 2005 CAIR was expected to serve as the
primary tool to assist downwind states in meeting the PM2.5 (and eight-hour ozone) NAAQS by
mitigating interstate transport of sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions from
electric generating units that contribute to the formation of PM2.5.75 The D.C. Circuit’s modified
decision reversed its decision to vacate CAIR while EPA developed a replacement rule, but left
the substantive requirements of its initial decision fully intact, eliciting additional concerns with
regard to the impact this may have on the implementation of the 2006 PM2.5 NAAQS in the
71 See footnote 8 and footnote 9.
72 See EPA’s guidance, “Area Designations for 2006 24-Hour PM2.5 NAAQS - Technical Information,” at
http://www.epa.gov/ttn/naaqs/pm/pm25_2006_techinfo.html.
73 Promulgated under the CAA, 42 U.S.C. 7401 et seq., 70 Federal Register 25162, May 12, 2005.
74 531 F.3d 896 (D.C. Cir. 2008), July 11, 2008, and 550 F.3d 1176 (D.C. Cir. 2008), December 23, 2008.
75 Sulfur dioxide (SO2) is a precursor (a pollutant that is transformed in air to form another air pollutant) contributing to
the formation of PM2.5, and NOx is a precursor contributing to the formation of both ozone and PM2.5. EPA has
concluded that SO2 and NOx emissions, through the phenomenon of air pollution transport, contribute significantly to
downwind nonattainment, or interfere with maintenance, of the PM2.5 and eight-hour ozone NAAQS (70 Federal
Register 25162, May 12, 2005).
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interim. EPA published a proposed “Transport Rule” intended to supersede the current CAIR on
August 2, 2010, and anticipates finalizing the alternative in spring of 2011.76
Recent air quality trends suggest that several factors, including national pollution control
regulations such as the implementation of CAIR Phase 1, car and truck emission rules, and New
Source Review (NSR) settlements, appear to be contributing to improved air quality. In a
February 2010 “Air Trends” summary,77 EPA reported that nationally, annual and 24-hour PM2.5
concentrations were 17% and 19% lower, respectively, in 2008 compared to 2001. Based on a
comparison of results from PM2.5 monitoring locations (565 sites) for two three-year periods,
2001-2003 and 2006-2008, EPA reported that almost all sites showed a decline or little change in
PM2.5 concentrations. On August 11, 2010, EPA reported that SO2 and NOx emissions (both PM2.5
precursors) had declined sharply in both 2008 and 2009; in the latter year, emissions from fossil-
fueled power plants in the lower 48 states (at 5.7 million tons) were 44% below 2005 levels. NOx
emissions from the same sources declined to 1.8 million tons in 2009, a decline of 45% compared
to 2005.78 Ultimately, the continued implementation of these national regulations and associated
air quality improvements should help nonattainment areas in achieving compliance with the
tighter 2006 PM2.5 NAAQS.
Implications of the various issues discussed above with regard to implementation of the 2006
PM2.5 NAAQS could vary significantly from area to area based on numerous factors. The
associated impacts on specific geographical nonattainment areas would be speculative at best,
because compliance with the 2006 revised particulates NAAQS is several years off. States are not
required to submit nonattainment SIPs until December 2012, and would not have to meet the
PM2.5 standard until December 2014 (or 2019, if qualified for an extension79).
The D.C. Circuit’s February 2009 decision regarding challenges to the 2006 PM NAAQS, delay
in designating nonattainment areas and implementing the 2006 PM2.5 NAAQS, impacts of the
D.C. Circuit’s 2008 decision regarding the 2005 CAIR and EPA’s pending alternative transport
regulation, and implications of recent preliminary findings of initial risk assessments supporting
EPA’s next round of periodic review of the particulate NAAQS suggesting the need to further
strengthen the standards, have prompted increased interest in the PM2.5 NAAQS. Concerns
regarding key implementation milestones and attainment deadlines for the 2006 PM2.5 NAAQS
will remain an issue of considerable debate for many stakeholders and interest groups, as well as
Congress.
76 75 Federal Register 45210-45565, August 2, 2010. See also U.S. EPA, “Air Transport” at http://www.epa.gov/
airtransport/actions.html#jul10. EPA announced the release of the proposal on July 6, 2010.
77 U.S. EPA, Our Nation’s Air: Status and Trends Through 2008, EPA-454/R-09-002, February 2010
http://www.epa.gov/airtrends/2010/index.html.
78 Data are from EPA’s “2009 Acid Rain Program Emission and Compliance Data Report,” August 11, 2010, at
http://www.epa.gov/airmarkets/progress/ARP09.html.
79 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.”
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Appendix A. Comparative Timeline for
Implementing the 1997 and 2006 PM2.5 NAAQS
The timeline presented in Table A-1 reflects the most recent key milestone dates for
implementing the 1997 and the 2006 PM2.5 NAAQS, including actual completions. These
milestones are driven primarily by statutory requirements. The table 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 1997 PM2.5 area designations,80 and
the agency’s previous and current projected timelines for the 2006 PM2.5 NAAQS.
Table A-1. Schedule for Implementation of the 1997 and the 2006 PM2.5 NAAQS
2006 PM2.5 NAAQS
Milestones
1997 PM2.5 NAAQS
Previous Schedule
Current Schedule
Revised standard promulgated
July 18, 1997
October 10, 2006
October 10, 2006
Revised standard effective date
September 1997
December 18, 2006
December 18, 2006
State-tribal area designation recommendations
February 2004 (based
December 18, 2007
December 18, 2007
on 2000-2002
(based on 2004-2006
(based on 2004-2006
monitoring data)
monitoring data)
monitoring data)
EPA notifies states and tribes regarding modifications
June-July 2004
August 2008
August 2008
to their recommendations
EPA promulgates final area designations (required
January 5, 2005
December 22, 2008
November 13, 2009
one year after states and tribes make
(based on 2005-2007
(based on 2006-2008
recommendations)
data; never published)
monitoring data)
EPA proposes PM2.5 implementation rule
November 1, 2005
NA
Spring 2011
Final Area designations effective date (typically not
April 5, 2005
April 2009 (delayed)
December 14, 2009
later than 90 days after Federal Register publication)
States with new transportation projects submit
April 5, 2006
December 22, 2009
December 14, 2010
conformity determination (required within one year
(delayed)
(projected)
of the effective date of nonattainment designation)
EPA promulgates final PM2.5 implementation rule
April 25, 2007
NA
December 2011
(projected)
States and tribes submit revised implementation
April 2008
April 2012 (delayed)
December 2012
plans (SIPs) (required three years after final area
(projected)
designations effective date unless extension granted)
NAAQS statutory compliance deadline for
April 2010-2015
April 2014-2019
December 2014-2019
attainment (required within five years after final area
(delayed)
(projected)
designations effective date; up to 10 years with
extension)
Source: Prepared by CRS based on EPA fact sheets and guidance documents and relevant Federal Register
notices. For EPA’s previous timeline as of January 2009, see http://www.epa.gov/oar/particlepollution/
naaqsrev2006.html; for EPA’s more current timeline as of August 2010, see http://www.epa.gov/pmdesignations/
2006standards/documents/2009-10-08/timeline.htm.
80 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.
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Appendix B. Comparison of Final and Interim
Nonattainment Designation Areas for the 2006 PM2.5
NAAQS and the Final Nonattainment Designation
Areas for the 1997 PM2.5 NAAQS
Table B-1. Nonattainment Areas for the 2006 PM2.5 NAAQS as Identified by EPA in
the October 8, 2009, Final Designations and in the December 28, 2008, Status Table,
and Final Nonattainment Designations for the 1997 PM2.5 NAAQS
2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
ALABAMA
Birmingham, AL
Jefferson Jefferson
Jefferson
Shelby Shelby
Shelby
Walker (p)
Walker (p)
Walker (p)
Chattanooga, AL-TN-GA
Jackson
(p)
ALASKA
Fairbanks, AK
Fairbanks N. Star (p)
Fairbanks N. Star (p)
Juneau, AK
Juneau
(p)
ARIZONA
Nogales, AZ
Santa Cruz (p)
Santa Cruz
CALIFORNIA
Chico, CA
Butte (p)
Butte (p)
Imperial County, CA
Imperial (p)
Imperial (p)
Los Angeles, CA
Los Angeles (p)
Los Angeles (p)
Los Angeles (p)
Los Angeles (p)
Orange
Orange
Orange
Orange
Riverside (p)
Riverside (p)
Riverside (p)
Riverside (p)
San Bernardino (p)
San Bernardino (p)
San Bernardino (p)
San Bernardino (p)
Sacramento, CA
El Dorado (p)
El Dorado (p)
Placer (p)
Placer (p)
Sacramento
Sacramento
Solano (p)
Solano (p)
Yolo (p)
Yolo (p)
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2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
San Francisco Bay Area, CA
Alameda Alameda
Contra Costa
Contra Costa
Marin
Marin
Napa
Napa
San Francisco
San Francisco
San Mateo
San Mateo
Santa Clara
Santa Clara
Solano (p)
Solano (p)
Sonoma (p)
Sonoma (p)
San Joaquin Val ey, CA
Fresno Fresno
Fresno Fresno
Kern (p)
Kern (p)
Kern (p)
Kern (p)
Kings
Kings
Kings
Kings
Madera
Madera
Madera
Madera
Merced
Merced
Merced
Merced
San Joaquin
San Joaquin
San Joaquin
San Joaquin
Stanislaus
Stanislaus
Stanislaus
Stanislaus
Tulare
Tulare
Tulare
Tulare
Yuba City-Marysville, CA
Sutter
Sutter
Yuba (p)
Yuba (p)
CONNECTICUT
New York, NY-NJ-CT
Fairfield Fairfield
Fairfield
New Haven
New Haven
New Haven
DELAWARE
Philadelphia- Wilmington,
New Castle
New Castle
New Castle
PA-NJ-DE
DISTRICT OF COLUMBIA
Washington, DC-MD-VA
Entire
District
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2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
GEORGIA
Atlanta, GA
Barrow
Bartow
Carroll
Cherokee
Clayton
Cobb
Coweta
De
Kalb
Douglas
Fayette
Forsyth
Fulton
Gwinnett
Hall
Heard
(p)
Henry
Newton
Paulding
Putnam
(p)
Rockdale
Spalding
Walton
Chattanooga, AL-TN-GA
Catoosa
Walker
Macon, GA
Bibb
Monroe
(p)
Rome, GA
Floyd
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2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
IDAHO
Logan, UT-ID
Franklin (p)
Franklin (p)
Pinehurst, ID
Shoshone
(p)
ILLINOIS
Chicago-Gary-Lake County,
Cook Cook
IL-IN
DuPage
DuPage
Grundy (p)
Grundy (p)
Kane
Kane
Kendall (p)
Kendall (p)
Lake
Lake
McHenry
McHenry
Will
Will
Davenport-Moline-Rock Island,
Rock
Island
IA-IL
Paducah-Mayfield, KY-IL
Massac
(p)
St. Louis, MO-IL
Madison
Madison
Monroe
Monroe
Randolph (p)
Randolph (p)
St. Clair
St. Clair
INDIANA
Chicago-Gary-Lake County,
Lake Lake
IL-IN
Porter
Porter
Cincinnati-Hamilton, OH-KY-IN
Dearborn (p)
Dearborn (p)
Evansville, IN
Dubois
Gibson (p)
Gibson (p)
Pike (p)
Pike (p)
Spencer (p)
Spencer (p)
Vanderburgh
Vanderburgh
Warrick
Warrick
Indianapolis, IN
Hamilton
Hamilton
Hendricks
Hendricks
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2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
Johnson
Johnson
Marion
Marion
Morgan
Morgan
Lafayette-Frankfort, IN
Tippecanoe
Louisville, KY-IN
Clark Clark
Floyd
Floyd
Jefferson (p)
Jefferson (p)
Vincennes, IN
Knox
IOWA
Davenport-Moline-Rock Island,
Scott
(p)
IA-IL
Muscatine, IA
Muscatine
(p)
KENTUCKY
Cincinnati-Hamilton, OH-KY-IN
Boone Boone
Campbel
Campbel
Kenton
Kenton
Clarksville, TN-KY
Muhlenberg
(p)
Huntington-Ashland,
Boyd Boyd
WV-KY-OH
Lawrence (p)
Lawrence (p)
Louisville, KY-IN
Bullitt Bullitt
Jefferson
Jefferson
Paducah-Mayfield, KY-IL
McCracken
MARYLAND
Baltimore, MD
Anne Arundel
Anne Arundel
Baltimore City
Baltimore City
Baltimore
Baltimore
Carroll
Carroll
Harford
Harford
Howard
Howard
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
Washington, DC-MD-VA
Charles
Frederick
Montgomery
Prince
George’s
Martinsburg, WV- Hagerstown,
Washington
MD
MICHIGAN
Detroit-Ann Arbor, MI
Livingston Livingston
Livingston
Macomb
Macomb
Macomb
Monroe
Monroe
Monroe
Oakland
Oakland
Oakland
St. Clair
St. Clair
St. Clair
Washtenaw
Washtenaw
Washtenaw
Wayne
Wayne
Wayne
Grand Rapids, MI
Kent
Ottawa
MISSOURI
St. Louis, MO-IL
Franklin
Franklin
Jefferson
Jefferson
St. Charles
St. Charles
St. Louis
St. Louis
St. Louis City
St. Louis City
MONTANA
Libby, MT
Lincoln (p)
Lincoln (p)
NEW JERSEY
New York, NY-NJ-CT
Bergen Bergen
Bergen
Essex
Essex
Essex
Hudson
Hudson
Hudson
Mercer
Mercer
Mercer
Middlesex
Middlesex
Middlesex
Monmouth
Monmouth
Monmouth
Morris
Morris
Morris
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2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
Passaic
Passaic Passaic
Somerset Somerset
Somerset
Union
Union
Union
Philadelphia- Wilmington,
Burlington Burlington
Burlington
PA-NJ-DE
Camden
Camden
Camden
Gloucester
Gloucester
Gloucester
NEW YORK
New York, NY-NJ-CT
Bronx Bronx
Bronx
Kings
Kings
Kings
Nassau
Nassau
Nassau
New York
New York
New York
Orange
Orange
Orange
Queens
Queens
Queens
Richmond
Richmond
Richmond
Rockland
Rockland
Rockland
Suffolk
Suffolk
Suffolk
Westchester
Westchester
Westchester
NORTH CAROLINA
Hickory, NC
Catawba
Greensboro-Winston Salem-
Davidson
High Point, NC
Guilford
OHIO
Canton-Massillon, OH
Stark Stark
Stark
Cincinnati-Hamilton, OH-KY-IN
Butler Butler
Clermont
Clermont
Hamilton
Hamilton
Warren
Warren
Cleveland-Akron- Lorain, OH
Ashtabula
(p)
Cuyahoga
Cuyahoga
Cuyahoga
Lake
Lake
Lake
Lorain
Lorain
Lorain
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2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
Medina
Medina
Medina
Portage
Portage
Portage
Summit
Summit
Summit
Columbus, OH
Coshocton (p)
Coshocton (p)
Delaware
Delaware
Fairfield
Fairfield
Franklin
Franklin
Licking
Licking
Dayton-Springfield, OH
Clark Clark
Greene
Greene
Montgomery
Montgomery
Huntington-Ashland,WV-KY-OH
Adams (p)
Adams (p)
Gallia (p)
Gallia (p)
Lawrence
Lawrence
Scioto
Scioto
Parkersburg- Marietta, WV-OH
Washington
Washington
Steubenville- Weirton, OH-WV
Jefferson Jefferson
Jefferson
Wheeling, WV-OH
Belmont
Youngstown, OH
Mahoning
Trumbull
OREGON
Klamath Falls, OR
Klamath (p)
Klamath (p)
Oakridge, OR
Lane (p)
Lane (p)
PENNSYLVANIA
Al entown, PA
Lehigh Lehigh
Northampton
Northampton
Harrisburg-Lebanon-Carlisle, PA
Cumberland Cumberland
a
Dauphin
Dauphin
Lebanon
Lebanon
York
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2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
Johnstown, PA
Cambria Cambria
Cambria
Indiana (p)
Indiana (p)
Indiana (p)
Lancaster, PA
Lancaster Lancaster
Lancaster
Liberty-Clairton, PA
Allegheny (p)
Allegheny (p)
Allegheny (p)
Philadelphia-Wilmington,
Bucks Bucks
Bucks
PA-NJ-DE
Chester
Chester
Chester
Delaware
Delaware
Delaware
Montgomery
Montgomery
Montgomery
Philadelphia
Philadelphia
Philadelphia
Pittsburgh-Beaver Val ey, PA
Allegheny (p)
Allegheny (p)
Allegheny (p)
Armstrong (p)
Armstrong (p)
Armstrong (p)
Beaver
Beaver
Beaver
Butler
Butler
Butler
Greene (p)
Greene (p)
Greene (p)
Lawrence (p)
Lawrence (p)
Lawrence (p)
Washington
Washington
Washington
Westmoreland
Westmoreland
Westmoreland
Reading, PA
Berks Berks
York, PA
York York
TENNESSEE
Chattanooga, AL-TN-GA
Hamilton
Clarksville, TN-KY
Humphreys
(p)
Montgomery
Stewart
(p)
Knoxville-Sevierville- La Follette,
Anderson Anderson
Anderson
TN
Blount
Blount
Blount
Knox
Knox
Knox
Loudon
Loudon
Loudon
Roane (p)
Roane (p)
Roane (p)
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2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
UTAH
Logan, UT-ID
Cache (p)
Cache (p)
Provo, UT
Utah (p)
Utah (p)
Salt Lake City, UT
Box Elder (p)
Box Elder (p)
Davis
Davis
Salt Lake
Salt Lake
Tooele (p)
Tooele (p)
Weber (p)
Weber (p)
VIRGINIA
Washington, DC-MD-VA
Alexandria
City
Arlington
Fairfax
City
Fairfax
Co
Fal s
Church
City
Loudoun
Manassas
City
Manassas Park City
Prince
William
WASHINGTON
Seattle-Tacoma, WA
Pierce (p)
Pierce (p)
WEST VIRGINIA
Charleston, WV
Kanawha Kanawha
Kanawha
Putnam
Putnam
Putnam
Huntington-Ashland,
Cabell Cabell
WV-KY-OH
Mason (p)
Mason (p)
Wayne
Wayne
Martinsburg, WV-Hagerstown,
Berkeley
MD
Morgantown, WV
Monongalia
Parkersburg- Marietta, WV-OH
Pleasants (p)
Pleasants (p)
Wood
Wood
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
2006 PM2.5 NAAQS
1997 PM2.5 NAAQS
EPA Final
EPA Dec. 2008
EPA Final
EPA Final
Designations
Interim Designations
Designations
Designations
24-Hour
24-Hour
24-Hour
Annual
Standard
Standard
Standard
Standard
State/Area Name
Counties and Partial Counties (p)
Steubenville- Weirton, OH-WV
Brooke Brooke
Brooke
Hancock
Hancock
Hancock
Wheeling, WV-OH
Marshall
Ohio
WISCONSIN
Green Bay, WI
Brown
Madison-Baraboo, WI
Columbia
(p)
Dane
Milwaukee-Racine, WI
Milwaukee Milwaukee
Racine
Racine
Waukesha
Waukesha
TOTALS
18 states
25 states
1 state
20 states and D.C.
31 areas
58 areas
2 areas
38 areas
120 counties
211 counties
12 counties
204 counties
90 whole counties
154 whole counties
9 whole counties
173 whole counties
30 partial counties
57 partial counties
3 partial counties
31 partial counties
Source: Compiled by CRS using data from EPA PM Designations websites. In some designated areas, EPA
included cities in the total count of whole and partial counties, with the exception of the District of Columbia.
a. In the August 25, 2008, Federal Register, EPA announced its determination that a three-county (Harrisburg,
Lebanon, Carlisle) Pennsylvania nonattainment area for the 1997 PM2.5 NAAQS was in attainment (73
Federal Register 49949, August 25, 2008). The determination was based on certified ambient air monitoring
data showing that the area monitored as in attainment for the 1997 PM2.5 NAAQS since the 2004-2006
monitoring period.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Appendix C. Tribal Lands: Designations for the 2006
PM2.5 NAAQS 24-Hour Standard
Table C-1. EPA’s October 8, 2009, Geographic Designations for 2006 PM NAAQS:
Tribes in 24-Hour PM2.5 Nonattainment Areas
State/Area Name
Tribes
CALIFORNIA
Chico, CA
Enterprise Rancheria of Maidu Indians of California
Mechoopda Indian Tribe of Chico Rancheria
Mooretown Rancheria of Maidu Indians of California
Los Angeles, CA
Cahuilla Band of Mission Indians of the Cahuilla Reservation
Morongo Band of Cahuilla Mission Indians of the Morongo Reservation
Pechanga Band of Luiseno Mission Indians of the Pechanga Reservation
Ramona Band or Village of Cahuilla Mission Indians of California
San Manuel Band of Serrano Mission Indians of the San Manuel Reservation
Soboba Band of Luiseno Mission Indians of the Soboba Reservation
Sacramento, CA
Shingle Springs Band of Miwok Indians, Shingle Springs Rancheria (Verona Tract)
United Auburn Indian Community of the Auburn Rancheria of California
San Francisco Bay Area, CA
Federated Indians of Graton Rancheria
Lytton Rancheria of California
San Joaquin Val ey, CA
Big Sandy Rancheria of Mono Indians of California
Santa Rosa Indian Community of the Santa Rosa Rancheria, California
Cold Springs Rancheria of Mono Indians of California
North Fork Rancheria of Mono Indians of California
Picayune Rancheria of Chukchansi Indians of California
Table Mountain Rancheria of California
Tule River Indian Tribe of the Tule River Reservation
WASHINGTON
Seattle-Tacoma, WA
Puyallup Tribe of the Puyallup Reservation, Washington
WISCONSINa
Milwaukee-Racine, WI
Forest County Potawatomi Tribe
Source: U.S. EPA, final designations as of October 8, 2009. Compiled by CRS using Tribal recommendations and
EPA responses, http://www.epa.gov/pmdesignations/2006standards/tribal.htm.
Note: The list of tribes is unofficial; official boundaries are specified in 40 CFR Part 81.
a. The Forest County Potawatomi Tribe was not included in EPA’s December 22, 2008, designations,
http://www.epa.gov/pmdesignations/2006standards/Dec08/tribal.htm. The December 22, 2008,
designations included the Oneida Tribe of Wisconsin and the Ho-Chunk Nation of Wisconsin in the Green
Bay and Madison-Baraboo nonattainment areas respectively. These two areas were not designated
nonattainment in EPA’s November 13, 2009, final designations.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Appendix D. Map Depicting Counties in
Nonattainment for the 2006 PM2.5 NAAQS:
EPA’s Designation as of December 22, 2008
On December 22, 2008, EPA had identified 58 areas in 25 states, comprising 211 counties (154
counties and portions of 57 additional counties) for designation as nonattainment for the revised
2006 24-hour PM2.5 standard.81 These designations, based on air quality monitoring data for
calendar years 2005 through 2007, are indicated in the map below.
Figure D-1. Counties in Nonattainment for the 2006 PM2.5 NAAQS:
EPA’s Designations as of December 22, 2008
(violating the 24-hour standard (35 μg/m3) only)
Source: Prepared by the Congressional Research Service based on EPA’s designations for the 2006 PM2.5
NAAQS as of December 22, 2008, with data obtained from EPA. See EPA’s “Area Designations for 2006 24-
Hour Fine Particulate (PM2.5) Standards—December 2008 Area Status (Not Final Designations),”
http://www.epa.gov/pmdesignations/2006standards/documents/2008-12-22/12-08table.htm.
81 See “Area Designations for 2006 24-Hour Fine Particulate (PM2.5) Standards—December 2008 Area Status (Not
Final Designations)” at http://www.epa.gov/pmdesignations/2006standards/documents/2008-12-22/12-08table.htm.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Author Contact Information
Robert Esworthy
Specialist in Environmental Policy
resworthy@crs.loc.gov, 7-7236
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