2006 National Ambient Air Quality Standards
(NAAQS) for Fine Particulate Matter (PM2.5):
Designating Nonattainment Areas
Robert Esworthy
Specialist in Environmental Policy
October 25, 2012
Congressional Research Service
7-5700
www.crs.gov
R40096
CRS Report for Congress
Pr
epared 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 Clean Air Act
(CAA) 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 most recent round of periodic review of the
particulates NAAQS and proposal to revise the PM NAAQS, published June 29, 2012, have
prompted further scrutiny of the ongoing implementation of the standards. EPA has agreed to
issue final revised PM NAAQS by December 14, 2012.
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. The publication of the final designations for the 2006 NAAQS—and thus the effective date of
the final designations—had initially been delayed pending review by the current Administration.
On November 13, 2009, EPA published its final designations for the 2006 PM NAAQS that
included 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 nonattainment area State Implementation Plans (SIPs), which identify specific regulations
and emission control requirements that would bring a nonattainment area into compliance.
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 was 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, was 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 the PM2.5 annual standard and for PM10.
The final designations for the 2006 PM2.5 NAAQS included a few areas designated nonattainment
for PM2.5 for the first time, but, as expected, the majority of the counties identified overlapped
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.
Congressional Research Service
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
2006 PM2.5 24-Hour NAAQS Designations .............................................................................. 6
Comparing the 2006 and 1997 PM2.5 NAAQS Designations .................................................. 10
Demonstrating Attainment with the 2006 PM2.5 NAAQS ............................................................. 14
State Implementation Plans (SIPs) .......................................................................................... 15
Status of Infrastructure SIPs .............................................................................................. 16
National Regulations ............................................................................................................... 17
New Source Review ................................................................................................................ 19
Transportation Conformity ...................................................................................................... 20
Conclusions .................................................................................................................................... 21
Figures
Figure 1. Counties in Nonattainment Only for the 2006 PM2.5 NAAQS 24-Hour Standard
(35 μg/m3): U.S. EPA Final Designations .................................................................................... 8
Figure 2. Counties in Nonattainment for the 1997 PM2.5 NAAQS Annual (15 μg/m3)
and/or 24-Hour (65 μg/m3) Standards: U.S. EPA Final Designations ........................................ 11
Figure 3. Counties in Nonattainment for the Revised PM2.5 NAAQS Annual (15 μg/m3;
Unchanged from 1997) and/or 24-Hour (35 μg/m3; as revised 2006) Standards: U.S.
EPA Final Designations .............................................................................................................. 13
Figure D-1. Counties in Nonattainment for the 24-Hour 2006 PM2.5 NAAQS:
EPA’s Designations as of December 22, 2008 ............................................................................ 36
Tables
Table 1. Counties in Nonattainment for the 1997 PM2.5 NAAQS and in Nonattainment for
the 2006 PM2.5 NAAQS: U.S. EPA Final Designations ............................................................. 12
Table A-1. Schedule for Implementation of the 1997 and the 2006 PM2.5 NAAQS ...................... 23
Table B-1. Nonattainment Areas for the 2006 24-Hour PM2.5 NAAQS as Identified by
EPA in the October 8, 2009, Final Designations and in the December 28, 2008,
Status Table, and Nonattainment Designations for the Annual and
24-Hour 1997 PM2.5 NAAQS ..................................................................................................... 24
Table C-1. EPA’s October 8, 2009, Geographic Designations for 2006 PM NAAQS:
Tribes in 24-Hour PM2.5 Nonattainment Areas ........................................................................... 35
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Appendixes
Appendix A. Comparative Time Line for Implementing the 1997 and 2006 PM2.5
NAAQS ...................................................................................................................................... 23
Appendix B. Comparison of EPA’s Final and Interim Nonattainment Designation Areas
for the 2006 24-Hour PM2.5 NAAQS and the Final Nonattainment Designation Areas
for the 1997 PM2.5 NAAQS ........................................................................................................ 24
Appendix C. Tribal Lands: U.S. EPA Designations for the 2006 PM2.5 NAAQS 24-Hour
Standard ...................................................................................................................................... 35
Appendix D. Map Depicting Counties in Nonattainment for the 2006 24-Hour PM2.5
NAAQS: EPA’s Designation as of December 22, 2008 .............................................................. 36
Contacts
Author Contact Information........................................................................................................... 37
Congressional Research Service
2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
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 nonattainment area 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 designation rule became effective
December 14, 2009 (30 days from the date of publication). The EPA final designations reflect a
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.
In a February 3, 2011, final notice, EPA published designations of three areas as “nonattainment” or
“unclassifiable/attainment” for the 2006 24-PM2.5 NAAQS that were deferred in the November 13, 2009, promulgated
designations, 76 Federal Register 6056-6066, http://www.epa.gov/pmdesignations/2006standards/documents/2011-01/
FR-2011-01.pdf. A portion of Pinal County, AZ, was designated nonattainment, eight surrounding counties were
designated unclassifiable/attainment, and Gila River Indian Community and the Ak-Chin Indian community
designations were deferred pending completion of the formal consultation process; Plumas County, CA, and Shasta
County, CA, were designated unclassifiable/attainment (includes surrounding counties).
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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 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 D.C. Circuit 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 has proceeded, the decision and EPA’s ongoing actions have prompted renewed
interest in PM NAAQS among Members of Congress.12
Simultaneously with the ongoing implementation of the 2006 PM NAAQS, EPA initiated its
current round of statutorily required periodic review of the PM NAAQS not long after the
October 2006 promulgation of the standards,13 in part in response to the D.C. Circuit Court’s
decision. On June 29, 2012, EPA published a proposal to strengthen the PM NAAQS. The June
2012 proposal would tighten the current PM NAAQS primarily by lowering the annual health-
based (“primary”) standard for PM2.5. The proposal includes options for new secondary standards
to address visibility impacts in urban areas associated with PM2.5, but did not modify the
standards for inhalable coarse particles smaller than 10 micrometers (PM10).14 EPA is to finalize
its decision regarding the PM NAAQS by December 14, 2012. In the interim, implementation of
the 2006 PM NAAQS continues. For an overview of the proposed revisions to the PM NAAQS
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.
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/sites/default/files/omb/assets/
information_and_regulatory_affairs/regulatory_review_012009.pdf. Also see Office of Management and Budget
website, “Regulatory Matters” - OIRA Policies and Practices, at http://www.whitehouse.gov/omb/
international_regulatory_cooperation.
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; see Office of Management and Budget website “Regulatory Matters” - OIRA Policies and Practices,
at http://www.whitehouse.gov/omb/international_regulatory_cooperation.
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 CRS Report RL34762, The National Ambient Air Quality
Standards (NAAQS) for Particulate Matter (PM): EPA’s 2006 Revisions and Associated Issues, by Robert Esworthy.
13 The current review was initiated with EPA’s June 2007 general call for information, U.S. EPA, “Integrated Science
Assessment for Particulate Matter: Call for Information,” 72 Federal Register 35462, June 28, 2007. See also EPA’s
Policy Assessment for the Review of the Particulate Matter National Ambient Air Quality Standards, pp. 1-10 through
1-12, U.S. EPA Office of Air Quality Planning and Standards, Health and Environmental Impacts Division, EPA
452/R-11-003, April 2011, http://www.epa.gov/ttnnaaqs/standards/pm/data/20110419pmpafinal.pdf.
14 See EPA’s Fact Sheet, “Overview of EPA’s Proposal to Revise the Air Quality Standards for Particle Pollution
(Particulate Matter),” http://www.epa.gov/pm/2012/fsoverview.pdf.
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published June 29, 2012, see CRS Report R42671, Air Quality: EPA’s 2012 Proposed Changes to
the Particulate Matter (PM) Standard, by Robert Esworthy.
The following sections of this report focus 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 did not require 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 time line 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, areas
proposed by the states for the 2006 24-hour 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 24-hour PM2.5 NAAQS.
EPA’s 2006 Changes to the Particulates NAAQS
The Clean Air Act (CAA) 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.15
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.
15 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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• 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
years; eliminated the annual maximum concentration (50 µg/m3) standard for
PM10.16
As discussed in more detail in the following section, strengthening the daily (24-hour) standard
for PM2.5 had 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 number of counties previously designated
nonattainment for PM10 have been determined by EPA to be in attainment since the 2006 revisions
of the particulates NAAQS were promulgated.17
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-tribal18 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”19 when they
meet the standard or when the data are insufficient for determining compliance with the NAAQS.
16 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.
17 See “Federal Register Notices Related to Particulate Matter (PM-10) Designations and Classifications” on EPA’s
“Green Book” website, http://www.epa.gov/air/oaqps/greenbk/pfrnrpt4.html#firstnotice. Also see discussion and map
(Figure 1) 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, under the
heading entitled “Rural PM10 Sources.”
18 Though not required, tribes have been encouraged to submit recommendations. The area designation requirements
under the CAA (§107) are specific with respect to states, but not to tribes. EPA follows the same designation process
for tribes per §§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.
19 §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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Following state and tribal designation submissions, the EPA Administrator has discretion to make
modifications, including to the area boundaries. As required by statute (§107(d)1(B)(ii)), the
agency must notify the states and tribes regarding any modifications, allowing them sufficient
opportunity to demonstrate why a proposed modification is inappropriate, but the final
determination rests with EPA.
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.20 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. 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.21 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 24-hour 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,22 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.
20 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).
21 Revisions to Ambient Air Monitoring Regulations, final rule, 71 Federal Register 61235-61328, October 17, 2006.
http://www.epa.gov/air/particlepollution/actions.html.
22 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.
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2006 PM2.5 24-Hour NAAQS Designations23
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.24 (See Table B-1 in Appendix B for state-by-state county/area
nonattainment designations.) The counties (and partial counties) that EPA designated as
nonattainment for the 2006 24-hour 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 24-hour PM2.5 24-hour standard, that were
previously designated nonattainment for the 24-hour 1997 PM2.5 NAAQS.
In the February 3, 2011, Federal Register,25 EPA published its final designations of three areas as
“nonattainment” or “unclassifiable/attainment” for the 2006 24-hour PM2.5 NAAQS that were
deferred at the time of the agency’s November 13, 2009, promulgated designations. Designations
were deferred so that EPA could evaluate measurements of high fine particle concentrations by
violating monitors. EPA designated a portion of Pinal County, AZ, as nonattainment. This
designation is not reflected in the map in Figure 1. Eight surrounding counties were designated
unclassifiable/attainment, and Gila River Indian Community and the Ak-Chin Indian community
designations were deferred pending completion of the formal consultation process. Plumas
County, CA, and Shasta County, CA, as well as surrounding counties, were designated
unclassifiable/attainment.
EPA’s November 2009 final designations, which were 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 for the 2006 24-hour PM2.5 standard 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
23 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.
24 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..
25 76 Federal Register 6056-6066, February 3, 2011, http://www.epa.gov/pmdesignations/2006standards/documents/
2011-01/FR-2011-01.pdf. See also, EPA’s Fact Sheet at http://www.epa.gov/pmdesignations/2006standards/regs.htm.
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.
The total number of nonattainment areas and counties includes the three-county (Jefferson, Shelby, and portion of
Walker) area of Birmingham. In the September 20, 2010, Federal Register, EPA announced its determination that a
three-county Alabama nonattainment area (Birmingham) has attaining data for the 2006 24-hour PM2.5 NAAQS (75
Federal Register 57186, September 20, 2010) based on certified ambient air monitoring data showing the area
monitored as in attainment for the 2006 24-hour PM2.5 NAAQS based on 2007-2009 data.
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as nonattainment for the 2006 24-hour 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 24-hour 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 designation rule is
December 14, 2009 (30 days from the date of publication).
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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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Figure 1. Counties in Nonattainment Only for the 2006 PM2.5 NAAQS 24-Hour Standard (35 μg/m3):
U.S. EPA Final Designations
Source: Prepared by the Congressional Research Service with data obtained from EPA based on EPA’s final designations for the 2006 24-hour
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. The map does not reflect EPA’s designation of a portion of Pinal County, AZ,
as nonattainment as published February 3, 2011, 76 Federal Register 6056-6066, February 3, 2011, http://www.epa.gov/pmdesignations/
2006standards/documents/2011-01/FR-2011-01.pdf. Designation of this area had been previously deferred.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
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 (more than 20% of the U.S. population)30 live in the 120 counties
designated nonattainment for the 2006 24-hour 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 (§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 24-hour 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 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 nine million, based on U.S. Census Bureau, 2010 Population Estimates, Census 2010,
http://2010.census.gov/2010census/data/.
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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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
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 24-hour PM2.5 NAAQS. EPA designations for the 2006 24-hour
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 24-
hour 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 24-hour 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 or both) 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 24-hour and annual 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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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Figure 2. Counties in Nonattainment for the 1997 PM2.5 NAAQS Annual (15 μg/m3)
and/or 24-Hour (65 μg/m3) Standards: U.S. EPA Final Designations
Source: Prepared by the Congressional Research Service based on EPA’s final designations for the 1997 PM2.5 NAAQS, with data obtained from EPA.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Table 1 below illustrates the comparative geographic distribution of counties designated
nonattainment for the 2006 24-hour PM2.5 NAAQS (based on EPA’s final designations as
published in the November 13, 2009, Federal Register), and those counties in EPA’s final area
designations for the annual and 24-hour 1997 PM2.5 NAAQS. Based on the final designations for
the 2006 24-hour 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 in Nonattainment for the 1997 PM2.5 NAAQS and in
Nonattainment for the 2006 PM2.5 NAAQS: U.S. EPA Final Designations
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 24-hour PM2.5 NAAQS, with the final designated
nonattainment areas for the annual standard under the 1997 PM2.5 NAAQS.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Figure 3. Counties in Nonattainment for the Revised PM2.5 NAAQS Annual (15 μg/m3; Unchanged
from 1997) and/or 24-Hour (35 μg/m3; as revised 2006) Standards: U.S. EPA Final Designations
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 24-hour 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 assess what effect the overlap of nonattainment designations may have had on
current control measures in these areas. In some areas, current measures that focused on
achieving attainment for the annual standard may have been sufficient to attain the 24-hour
standard as well. Other areas may have required 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. These often involve promulgation of new regulations by states, leading to the issuance
of revised air permits, which affect pollution control requirements at various facilities.
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 by December 2012, three years after the
effective date of the agency’s final designations of December 14, 2009.41 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, which would be December 2014, unless an extension allowed under
the CAA is granted.42
40 §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 §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 §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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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
State Implementation Plans (SIPs)
Within three years of promulgation of a new or revised NAAQS (or shorter period as EPA may
prescribe), Section 110(a)(1) of the CAA requires states to submit revised SIPs that provide for
implementation, maintenance, and enforcement of the new or revised NAAQS. 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, 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; and
• prohibition of interstate pollution transport.
Section 110(a)(2)(D)(i) of the act contains four elements that revised SIPs must address. The first
two elements of this section require each state in its SIP to demonstrate adequate provisions for
the ability to prohibit air emissions within the state that (1) contribute significantly to another
state’s nonattainment of the NAAQS, or (2) interfere with another state’s maintenance of the
NAAQS.
Three years from the effective date of the final designations, states and local governments are
required to develop and implement new or revised plans (SIPs) for addressing emissions in those
“nonattainment” areas that do not meet the new or revised NAAQS. Nonattainment area SIPS for
the 2006 PM2.5 NAAQS are required to be submitted to EPA for review and approval by
December 2012. As previously indicated, the effective date of the final designation rule is
December 14, 2009 (30 days from the date of publication). 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.
Several counties designated as nonattainment for the PM2.5 NAAQS were 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 were unable to
meet the 2006 revised 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)43 outlining an
implementation plan for the transition to the 2006 particulates standards, EPA indicated that it
43 71 Federal Register 6718, February 9, 2006.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
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.
The basic framework of the implementation rule for the 1997 PM2.5 NAAQS published in April
of 2007 provides guidance for implementation of the 2006 standards.44 The implementation rule
describes the requirements that states and tribes must meet in their implementation plans to
achieve and maintain attainment. The rule also provides guidance and procedures for establishing
controls to achieve and maintain attainment. The implementation rule also includes guidance for
submitting a SIP when reaching attainment within the five-year requirement is impractical. The
implementation rule takes into account existing (oftentimes pending) federal regulations that
contribute to controlling criteria pollutants and their precursors.45 In addition to the 2007
implementation rule for the 1997 PM2.5 NAAQS, EPA outlined implementation guidance
regarding the development of SIPs to demonstrate attainment with the 2006 PM2.5 NAAQS in a
March 12, 2012, memorandum to EPA Regional Air Directors.46
Status of Infrastructure SIPs
On June 9, 2010, EPA published a finding that 23 states, the District of Columbia, and 5
territories had failed to submit “infrastructure” SIPs to address the requirements of CAA Section
110(a)(2)(D)(i)(I) with respect to the 2006 PM2.5 NAAQS.47 On July 20, 2011, EPA published a
notice finding that one additional state had failed to submit a SIP to address those
requirements.48 Both of EPA’s findings notices49 addressed the first two of four elements under
Section 110(a)(2)(D)(i) to satisfy interstate transport requirements. In an August 8, 2011, Federal
Register notice, EPA promulgated a series of FIPs through the Cross-State Air Pollution Rule
(CSAPR) which were to address the emissions from 28 states that significantly affect downwind
states’ ability to attain and maintain compliance with the 2006 (and 1997) PM2.5 NAAQS (as well
as the 1997 ozone NAAQS).50,51 These FIPs limited emissions through the regulation of electric
44 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).
45 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.
46 March 12, 2012, Memorandum from Stephen D. Page, Director, Office of Air Quality Planning and Standards, to
EPA Regional Air Directors (Regions I-X), “Implementation Guidance for the 2006 24-Hour Fine Particle (PM2.5)
National Ambient Air Quality Standards (NAAQS),” http://www.epa.gov/ttn/naaqs/pm/pdfs/
20120302_implement_guidance_24-hr_pm2.5_naaqs.pdf.
47 U.S. EPA, “Finding of Failure To Submit Section 110 State Implementation Plans for Interstate Transport for the
2006 National Ambient Air Quality Standards for Fine Particulate Matter,” 75 Federal Register 32673-32676, June 9,
2010. See also EPA’s Fact Sheet at http://www.epa.gov/air/particlepollution/actions.html.
48 U.S. EPA, “Finding of Failure To Submit Section 110 State Implementation Plans for Interstate Transport for the
2006 National Ambient Air Quality Standards for Fine Particulate Matter,” 76 Federal Register 43180-43183, July 20,
2011. See also EPA’s Fact Sheet at http://www.epa.gov/air/particlepollution/actions.html.
49 Under the CAA, the EPA findings notice initiates a two-year deadline for the agency 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.
50 U.S. EPA, “Federal Implementation Plans: Interstate Transport of Fine Particulate Matter and Ozone and Correction
of SIP Approvals, 76 Federal Register 48208-48483, August 8, 2011, http://www.gpo.gov/fdsys/pkg/FR-2011-08-08/
pdf/2011-17600.pdf. In the Notice, EPA also modified its prior approvals of certain SIPs, rescinding statements that the
(continued...)
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
generating units. Eleven states identified in the findings notices were included in EPA’s CSAPR.
On August 21, 2012, the U.S. Court of Appeals for the District of Columbia issued a 2-1 decision
to vacate and remand the CSAPR. On October 5, 2012, the U.S. Department of Justice filed a
petition52 seeking en banc rehearing of the D.C. Circuit’s August 21, 2012, decision regarding the
CSAPR.
In a separate Notice published September 8, 2011, EPA notified six states, the District of
Columbia, and the Commonwealth of Puerto Rico that they failed to submit complete
infrastructure SIPs that include required elements to ensure the implementation of the 2006 24-
hour PM2.5 NAAQS.53 In some cases the submission was missing only one or two elements, while
others were missing multiple elements.54
At the time this report was updated, EPA had approved, or approved portions of, submissions
from a number of states. In most cases the elements not approved were with regard to interstate
requirements.
National Regulations
EPA expects that in many cases emission reductions from implementing national regulations and
strategies would provide a framework for helping states achieve attainment with the PM2.5
NAAQS. These national actions include the
• Cross-State Air Pollution Rule (CSAPR);55
• Mercury and Air Toxics Standards (MATS);56
• Light-Duty Vehicle Tier 2 Rule;57
• Heavy Duty Diesel Rule;58
• Clean Air Nonroad Diesel Rule;59
• Regional Haze Regulations and Guidelines for Best Available Retrofit
Technology Determinations;60
(...continued)
submitted SIPs satisfy the interstate transport FIPs with respect to the 1997 PM2.5 NAAQS (and the 1997 ozone
NAAQS) for 22 states.
51 U.S. EPA, “Federal Implementation Plans for Iowa, Michigan, Missouri, Oklahoma, and Wisconsin and
Determination for Kansas Regarding Interstate Transport of Ozone,” 76 Federal Register 80760-80777 December 27,
2011.
52 http://epa.gov/crossstaterule/pdfs/Rehearing_Petition_617874.pdf,. For status of the petition see EPA website
“Cross-State Air Pollution Rule (CSAPR)” http://epa.gov/crossstaterule/.
53 U.S. EPA, “Findings of Failure to Submit a Complete State Implementation Plan for Section 110(a) Pertaining to the
2006 Fine Particulate Matter (PM2.5 ) NAAQS, 76 Federal Register 55577-55581, September 8, 2011.
54 See the table summarizing the missing elements for each of the six states, District of Columbia, and Puerto Rico
presented in EPA’s Fact Sheet, available at http://www.epa.gov/air/particlepollution/actions.html.
55 76 Federal Register 48208-48483, August 8, 2011.
56 77 Federal Register 9304-9513, February 16, 2012.
57 65 Federal Register 6822-6870, February 10, 2000.
58 65 Federal Register 59896-59978, October 6, 2000.
59 69 Federal Register 38958-39273, January 29, 2004.
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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
• NOx Emission Standard for New Commercial Aircraft Engines;61
• Emissions Standards for Locomotives and Marine Compression-Ignition
Engines;62
• Emission Standards Ignition Engines, Control of Emissions for Nonroad Spark
Ignition Engines and Equipment;63
• Category 3 Oceangoing Vessels;64
• Reciprocating Internal Combustion Engines (RICE) National Emissions
Standards for Hazardous Air Pollutants (NESHAPS);65 and
• New Source Performance Standards and Emissions Guidelines for
Hospital/Medical/Infectious Waste Incinerators Final Rule Amendments.66
Stakeholders and some Members of Congress have been skeptical about EPA’s expectations with
respect to the corollary benefits associated with some of these regulations, and have raised
concerns about pending efforts to delay some of the more recent programs and historical delays
of others. For example, one of the key federal regulations that was designed to control emissions
of air pollution that causes air quality problems in downwind states, EPA’s May 2005 Clean Air
Interstate Rule (CAIR),67 was vacated in a July 11, 2008, decision (North Carolina v. EPA), by the
U.S. Court of Appeals for the D.C. Circuit.68 The D.C. Circuit subsequently modified its decision
on December 23, 2008,69 in response to an EPA motion,70 reversing its decision to vacate CAIR
while EPA developed a replacement rule. The subsequent replacement rule, the Cross-State Air
Pollution Rule (“Cross-State Rule” or CSAPR),71 was to have gone into effect in 2012 but was
stayed in December 2011, then vacated on August 21, 2012, by the D.C. Circuit Court of
(...continued)
60 70 Federal Register 39104-39172, July 6, 2005.
61 70 Federal Register 69644-69687, November 17, 2005.
62 73 Federal Register 37095-37144, republished June 30, 2008.
63 73 Federal Register 59034-59380, October 8, 2008.
64 75 Federal Register 22896-23065, April 30, 2010.
65 75 Federal Register 51570-51608, August 20, 2010; Proposed Amendments 77 Federal Register 33812-33857, June
7, 2012.
66 74 Federal Register 51368-51415, October 6, 2009.
67 Promulgated under the CAA, 42 U.S.C. 7401 et seq., see U.S. EPA, “Ambient air quality standards, national—Fine
particulate matter and ozone; interstate transport control measures,” 70 Federal Register 25162, May 12, 2005.
68 North Carolina v. EPA, 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’s Clean Air Interstate Rule website at http://www.epa.gov/CAIR/index.html.
69 550 F.3d 1176 (D.C. Cir. 2008).
70 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.
71 See U.S. EPA, “Federal Implementation Plans: Interstate Transport of Fine Particulate Matter and Ozone and
Correction of SIP Approvals,” 76 Federal Register 48208-48483, August 8, 2011, http://www.gpo.gov/fdsys/pkg/FR-
2011-08-08/pdf/2011-17600.pdf. Explanatory and background material can be found on EPA’s website at
http://www.epa.gov/crossstaterule/actions.html.
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Appeals.72 The U.S. Department of Justice filed a petition73 on October 5, 2012, seeking en banc
rehearing of the D.C. Circuit’s August 21, 2012, decision regarding the CSAPR.
Additionally, EPA itself has stayed the Mercury and Air Toxics Standards (MATS), pending
reconsideration. Other remanded rules include the hazardous air pollutant (“MACT”) standards
for boilers and cement kilns. EPA has delayed implementation of the boiler MACT rules for more
than a year and a half while considering changes to the requirements. The agency has also
extended the compliance deadline for the cement kiln MACT by two years.
These actions have had a disruptive effect on certain aspects of the implementation of the 2006
revised PM2.5 NAAQS.
New Source Review74
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.75
EPA promulgated a rule in May 200876 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 October 20,
2010, EPA published a final rule amending requirements under the Clean Air Act PSD program
for PM2.5.77 This final rule establishes several components addressing air quality modeling and
monitoring provisions when making PSD permitting determinations for fine particle pollution.
The final rule adds maximum allowable increases in ambient pollutant concentrations or
“increments,” which is the mechanism used to estimate significant deterioration of ambient air
quality for a pollutant. EPA also added two screening tools, referred to as Significant Impact
72 EME Homer City Generation, L.P. v. Environmental Protection Agency, D.C. Cir., No. 11-1302, August 21, 2012,
http://www.cadc.uscourts.gov/internet/opinions.nsf/19346B280C78405C85257A61004DC0E5/$file/11-1302-
1390314.pdf. See also U.S. EPA’s website “Cross-State Air Pollution Rule (CSAPR)” for this decision and other
related documents.
73 http://epa.gov/crossstaterule/pdfs/Rehearing_Petition_617874.pdf,. For status of the petition see EPA website
“Cross-State Air Pollution Rule (CSAPR)” http://epa.gov/crossstaterule/.
74 For an overview, including statutory authority and regulations, see EPA’s “New Source Review (NSR)” at
http://www.epa.gov/air/nsr/.
75 See Clean Air Act, Part D—Plan Requirements for Nonattainment Areas, §§171-178, codified at 40 CFR
52.24(f)(10). §166 of the CAA authorizes EPA to establish regulations for PSD of any pollutant for which EPA has
issued a national standard.
76 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.
77 “Prevention of Significant Deterioration (PSD) for Particulate Matter Less Than 2.5 Micrometers (PM2.5)—
Increments, Significant Impact Levels (SILs) and Significant Monitoring Concentration (SMC),” 75 Federal Register
64864, http://www.gpo.gov/fdsys/pkg/FR-2010-10-20/pdf/2010-25132.pdf. See also EPA’s Fact Sheet at
http://www.epa.gov/nsr/documents/20100929factsheet.pdf.
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Levels (SILs) and Significant Monitoring Concentration (SMC) for PM2.5. SILs are used to
determine whether a proposed source’s emissions will have a “significant” impact on air quality
in the area; the SMC may be used to determine if a source must submit to the permitting authority
one year of pre-construction air quality monitoring data prior to constructing or modifying a
facility.78
On May 10, 2011, EPA issued a final rule to repeal a provision in the rule implementing the NSR
permitting program for PM2.5, known as “the grandfathering provision,” in part in response to
petitions79 to reconsider the May 2008 final NSR rule.80 The provision allowed applicants for
federal 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 decided not to take any action that would end the PM10 Surrogate
Policy. 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. States with EPA-approved PSD programs could use the surrogate policy
until May 2011, or until EPA approved the revised State Implementation Plan (SIP) for PM2.5. The
agency had proposed to end the policy which had been in place since 1987, sooner than currently
scheduled.81
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),82 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.83 The final rule, which affects
78 EPA’s Fact Sheet at http://www.epa.gov/nsr/documents/20100929factsheet.pdf.
79 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.
80 See “Implementation of the New Source Review (NSR) Program for Particulate Matter Less Than 2.5 Micrometers
(PM2.5); Final Rule To Repeal Grandfather Provision,” 76 Federal Register 28646-28991, May 18, 2011,
http://www.gpo.gov/fdsys/pkg/FR-2011-05-18/pdf/2011-12089.pdf. See also EPA’s Fact Sheet at http://www.epa.gov/
air/nsr/documents/20110512grandfatherfs.pdf.
81 EPA proposed repealing the “grandfather” provision, February 11, 2010, see “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.
82 42 U.S.C. 7506(c).
83 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
(continued...)
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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.
On March 14, 2012, EPA published a final rule restructuring sections of the conformity rule (40
CFR 93.109 and 93.119) so that existing requirements apply to new or revised NAAQS, and
released associated implementation guidance in July 2012. The rule is intended to remove the
need to amend the transportation conformity rule merely to reference specific new NAAQS.
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.84 Although EPA and
states continue the implementation of the 2006 revised PM2.5 standards, the next round of periodic
review of the particulates PM NAAQS is ongoing, and on June 29, 2012, EPA published a
proposal that would further tighten the PM2.5 standards. EPA has agreed to issue final revised PM
NAAQS by December 14, 2012.
On November 13, 2009, EPA published its final designations of areas as nonattainment and
unclassifiable/attainment for the 2006 24-hour PM2.5 NAAQS. Publication of a final designation
rule for the 2006 24-hour 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.85 Delaying publication of the final designation rule resulted in the delay
of the expected effective date of April 200986 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 24-hour PM2.5 NAAQS.
(...continued)
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.
84 American Farm Bureau Federation v. U.S. EPA, No. 06-1410 (D.C. Cir., February 24, 2009).
85 See footnote 8 and footnote 9.
86 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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Within three years of promulgation of the 2006 PM2.5 NAAQS, all states were required to
demonstrate that they have the basic infrastructure and capacity necessary to implement the 2006
PM2.5 NAAQS. By December 19, 2012, three years following the publication of the final
designations, state, local, and tribal governments are to submit 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.
EPA anticipated that in many cases emission reductions from implementing national regulations
and strategies would provide a framework for helping states achieve attainment with the PM2.5
NAAQS. However, decisions by the D.C. Circuit to vacate two key federal regulations designed
to control emissions of air pollution that causes air quality problems in downwind states, EPA’s
May 2005 CAIR87 and its replacement CSAPR published in 2011,88 have elicited concerns with
regard to the implications this may have on the implementation of the 2006 PM2.5 NAAQS.
Nevertheless, recent air quality trends suggest that several factors, including national pollution
control regulations, appear to be contributing to improved air quality. In a February 2012 report,
“Our Nation’s Air—Status and Trends through 2010,”89 EPA reported that nationally, annual and
24-hour PM2.5 concentrations were 24% and 28% lower, respectively, in 2010 compared to 2001.
In its February 2012 report, EPA indicated that nationally, annual mean concentrations of SO2 and
NOx (both PM2.5 precursors) decreased 33% and 50%, respectively, between 2001 and 2010. EPA
expects air quality to continue to improve with implementation of more recently adopted
regulations and states’ work to meet current and recently revised national air quality standards.
Key regulations include the Locomotive Engines and Marine Compression-Ignition Engines
Rule, the Tier 2 Vehicle and Gasoline Sulfur Rule, the Heavy-Duty Highway Diesel Rule, the
Clean Air Non-Road Diesel Rule, and the Mobile Source Air Toxics Rule.
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.
The D.C. Circuit’s February 2009 decision regarding challenges to the 2006 PM NAAQS, delays
in designating nonattainment areas and implementing the 2006 PM2.5 NAAQS, impacts of the
D.C. Circuit’s decisions regarding the 2005 CAIR and 2011 CSAPR transport regulations, and
potential implications of EPA’s June 2012 proposal to further revise the PM NAAQS have
prompted increased interest in the PM2.5 NAAQS. Implications of the various issues could vary
significantly from area to area based on numerous factors. The associated impacts on specific
geographical nonattainment areas would be speculative at best. Implementation milestones and
attainment deadlines for the 2006 PM2.5 NAAQS remain an area of concern for many
stakeholders and interest groups, as well as Congress.
87 Promulgated under the CAA, 42 U.S.C. 7401 et seq., see U.S. EPA, “Ambient air quality standards, national—Fine
particulate matter and ozone; interstate transport control measures,” 70 Federal Register 25162, May 12, 2005.
88 76 Federal Register 48208-48483, August 8, 2011.
89 U.S. EPA, Our Nation’s Air—Status and Trends through 2010, EPA-454/R-12-001, February 2012,
http://www.epa.gov/airtrends/2011/.
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Appendix A. Comparative Time Line for
Implementing the 1997 and 2006 PM2.5 NAAQS
The time line 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,90 and
the agency’s previous and current projected time lines 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)
(delayed)
of the effective date of nonattainment designation)
EPA promulgates final PM2.5 implementation rule
April 25, 2007
NA
December 2011
(projected delayed)
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 time line as of January 2009, see http://www.epa.gov/oar/particlepol ution/
naaqsrev2006.html; for EPA’s time line as of July 19, 2012, see http://www.epa.gov/pmdesignations/
2006standards/documents/2011-01/timeline.htm.
90 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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2006 Fine Particulate Matter (PM2.5) NAAQS Nonattainment Designations
Appendix B. Comparison of EPA’s Final and Interim
Nonattainment Designation Areas for the 2006 24-
Hour PM2.5 NAAQS and the Final Nonattainment
Designation Areas for the 1997 PM2.5 NAAQS
Table B-1. Nonattainment Areas for the 2006 24-Hour PM2.5 NAAQS as Identified by
EPA in the October 8, 2009, Final Designations and in the December 28, 2008,
Status Table, and Nonattainment Designations for the Annual and
24-Hour 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, ALa
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
Pinal, CA
Pinal (p) (designated February 3, 2011)b
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)
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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)
Yolo (p)
Yolo (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 Valley, 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 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)
GEORGIA
Atlanta, GA
Barrow
Bartow
Carrol
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 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)
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 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)
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
Carrol
Carrol
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 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)
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,
Adams (p)
Adams (p)
WV-KY-OH
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
Allentown, PA
Lehigh Lehigh
Northampton
Northampton
Harrisburg-Lebanon-Carlisle, PA
Cumberland Cumberland
c
Dauphin
Dauphin
Lebanon
Lebanon
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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)
York
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 Valley, 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 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)
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
Falls 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 September 20, 2010, Federal Register, EPA announced its determination that a three-county (Jefferson,
Shelby, and portion of Walker) Alabama nonattainment area (Birmingham) has attaining data for the 2006
24-hour PM2.5 NAAQS (75 Federal Register 57186, September 20, 2010). The clean air data determination
was based on certified ambient air monitoring data showing the area monitored as in attainment for the
2006 24-hour PM2.5 NAAQS based on 2007-2009 data.
b. In a February 3, 2011 final notice, EPA published designations of three areas as “nonattainment” or
“unclassifiable/attainment” for the 2006 24-PM2.5 NAAQS that were deferred in the November 13, 2009,
promulgated designations, 76 Federal Register 6056-6066,http://www.epa.gov/pmdesignations/2006standards/
documents/2011-01/FR-2011-01.pdf.
c. 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 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: U.S. EPA 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 Cahuil a 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 Valley, 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 24-Hour 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.91 These designations, based on air quality monitoring data for
calendar years 2005 through 2007, are indicated in the map below for purposes of comparison
with the November 2009 final designations.
Figure D-1. Counties in Nonattainment for the 24-Hour 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.
91 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
Congressional Research Service
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