Air Quality: EPA’s 2013 Changes to the
Particulate Matter (PM) Standard
Robert Esworthy
Specialist in Environmental Policy
January 7, 2015
Congressional Research Service
7-5700
www.crs.gov
R42934
Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Summary
On January 15, 2013, the Environmental Protection Agency (EPA) published a final rule revising
the National Ambient Air Quality Standard (NAAQS) for particulate matter (PM). The revised air
quality standards were completed pursuant to the Clean Air Act (CAA) and, in part, in response to
a court order and consent agreement. Based on its review of scientific studies available since the
agency’s previous review in 2006, EPA determined that evidence continued to show associations
between particulates in ambient air and numerous significant health problems, including
aggravated asthma, chronic bronchitis, nonfatal heart attacks, and premature death. Populations
shown to be most at risk include children, older adults, and those with heart and lung disease, and
those of lower socioeconomic status. EPA’s review of and revisions to the PM NAAQS have
generated considerable debate and oversight in Congress.
The January 2013 revisions change the existing (2006) annual health-based (“primary”) standard
for “fine” particulate matter 2.5 micrometers or less in diameter (or PM2.5), lowering the
allowable average concentration of PM2.5 in the air from the current level of 15 micrograms per
cubic meter (µg/m3) to a limit of 12 µg/m3. The annual PM2.5 NAAQS is set so as to address
human health effects from chronic exposures to the pollutants. The existing “24-hour primary
standard” for PM2.5 that was reduced from 65 µg/m3 to 35 µg/m3 in 2006 was retained, as was the
existing standard for larger, but still inhalable, “coarse” particles less than 10 micrometers in
diameter, or PM10. As it did in 2006, EPA set “secondary” standards that provide protection
against “welfare” (nonhealth) effects, such as ecological effects and material deterioration,
identical to the primary standards.
EPA revised the Regulatory Impact Analysis (RIA) accompanying its June 2012 proposed rule in
part in response to comments received regarding the agency’s cost and benefit estimates. In its
December 2012 RIA, EPA estimated that the potential “quantifiable” health benefits (2010 $)
associated with attaining the PM standard would range from $4.0 billion to $9.1 billion, and costs
(2010 $) would range from $53.0 million to $353.0 million. Some stakeholders and some
Members continue to express concerns that cost impacts would be more significant than those
estimated by EPA for those areas out of compliance with the new standards.
EPA’s revisions to the PM NAAQS do not directly regulate emissions from specific sources, or
compel installation of any pollution control equipment or measures, but indirectly could affect
operations at industrial facilities and other sources throughout the United States. Revising PM
NAAQS starts a process that includes a determination of areas in each state that exceed the
standard and must, therefore, reduce pollutant concentrations to achieve it. Following
determinations of these “nonattainment” areas based on multiple years of monitoring data and
other factors, state and local governments must develop (or revise) State Implementation Plans
(SIPs) outlining measures to attain the standard. These include promulgation of new regulations
by states, and the issuance of revised air permits. The process typically takes several years.
As per statutory scheduling requirements, on December 18, 2014, EPA classified 14 areas as
“Moderate” nonattainment for the revised 2013 primary annual PM2.5 standard. The areas include
38 counties or portions of counties in six states—California, Idaho, Indiana, Kentucky, Ohio, and
Pennsylvania. EPA also deferred the designation period for 11 other areas by up to one year, and
designated all other areas as “unclassifiable” or as “unclassifiable/attainment.” CAA section
188(c) requires Moderate areas to achieve attainment as expeditiously as practicable, but no later
than six years after the effective date of final area designation.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Contents
Introduction ...................................................................................................................................... 1
Background ...................................................................................................................................... 4
EPA’s January 2013 Final Changes to the PM NAAQS .................................................................. 6
Comparison of the January 2013 Revised PM2.5 Standards with Previous Promulgated
and Proposed Alternative PM Standards ................................................................................ 8
Review Process Leading Up to the January 2013 Revised PM NAAQS ........................................ 9
Implementing the Revised PM2.5 NAAQS ..................................................................................... 12
Nonattainment Area Designation Process ............................................................................... 13
January 2013 Final Revised PM2.5 Annual NAAQS: Area Designations .......................... 14
State Implementation Plans (SIPs) .......................................................................................... 17
National Regulations ............................................................................................................... 18
Potential Impacts of More Stringent PM Standards ....................................................................... 20
Reaction to the Revised PM NAAQS ............................................................................................ 22
Congressional Activity ................................................................................................................... 23
Conclusions .................................................................................................................................... 25
Figures
Figure 1. EPA December 2014 Counties Designated Nonattainment for 2013 PM2.5
NAAQS Compared to Their Final Designations for 2006 and 1997 PM2.5 NAAQS ................. 16
Figure C-1. Counties Not Meeting the January 2013 Revised Primary Annual PM2.5
NAAQS Based on 2009-2011 Air Monitoring Data as Predicted by EPA ................................. 32
Tables
Table 1. Promulgated, Proposed, and Alternative PM2.5 Primary (Health) National
Ambient Air Quality Standards (NAAQS) ................................................................................... 9
Table 2. EPA’s Estimated Total Monetized Benefits, Costs, and Net Benefits of Attaining
Alternative PM2.5 NAAQS as in 2020 for the January 2013 Final Rule ..................................... 21
Table A-1. Milestone Chronology for Actions Subsequent to the January 2013 Final
Revisions to the PM NAAQS ..................................................................................................... 27
Table B-1. Chronological Listing of EPA Workshops, and Technical and Policy
Documents in Support of the 2013 Revised PM NAAQS .......................................................... 28
Table B-2. Chronological Listing of CASAC Reviews and Consultations ................................... 30
Table C-1. Nonattainment Areas for the January 2013 24-Hour PM2.5 NAAQS as
Estimated Using 2009-2011 Data, Final Designations 2006 24-Hour PM2.5 NAAQS
October 8, 2009, and Final Designations for the 1997 PM2.5 NAAQS Annual .......................... 33
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Appendixes
Appendix A. Chronological Summary of Key Milestones Subsequent to the
January 2013 PM NAAQS Final Rule ........................................................................................ 27
Appendix B. Supporting EPA Scientific and Policy Documents, and CASAC Review ................ 28
Appendix C. Comparison of Potential Nonattainment Areas for the January 2013 Final
Revised PM2.5 Annual Standard with the Final Designations for the 2006 and 1997
PM2.5 NAAQS ............................................................................................................................. 31
Contacts
Author Contact Information........................................................................................................... 45
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Introduction
On January 15, 2013, the Environmental Protection Agency (EPA) published a final rule in the
Federal Register to strengthen the National Ambient Air Quality Standard (NAAQS) for
particulate matter (PM).1 The standards, set pursuant to the Clean Air Act (CAA),2 address
potential health effects (including chronic respiratory disease and premature mortality) associated
with short- and long-term exposure to particulate matter. The CAA, enacted in 1970 and amended
in 1990, requires EPA to set minimum NAAQS standards for pollutants anticipated to endanger
public health and welfare, and where their presence in ambient air results from numerous and
diverse mobile or stationary sources. EPA has identified six “criteria air pollutants” under this
authority: ozone (“smog”), particulate material (“soot”), sulfur dioxides, nitrogen oxides, carbon
monoxide, and lead. The law also requires EPA to evaluate each NAAQS every five years to
determine whether it is adequately protective of human health and the environment, based on the
most recent science.3
The EPA Administrator signed the final PM NAAQS rule on December 14, 2012.4 EPA’s most
recent review and process generated controversy and national debate among a variety of
stakeholders including industry groups, health and environmental advocacy groups, and states, as
well as oversight in Congress. EPA reportedly received and considered more than 230,000 written
comments in determining the final PM standard.5 Similar controversy and debate transpired
during the previous changes leading up to the PM NAAQS promulgated October 2006, and those
established in 1997.
As published, January 2013 final PM NAAQS rule was the culmination of EPA’s statutorily
required review of the NAAQS under the CAA based on studies available through mid-2009 and
recommendations of EPA staff and a scientific advisory panel (Clean Air Scientific Advisory
Committee, or CASAC)6 established by the CAA.7 The agency initiated the statutorily required
1 U.S. Environmental Protection Agency, “National Ambient Air Quality Standards for Particulate Matter; Final Rule,”
78 Federal Register 3086, January 15, 2013; http://www.gpo.gov/fdsys/pkg/FR-2013-01-15/pdf/2012-30946.pdf. The
final rule and supporting documents are available on EPA’s website Particulate Matter (PM): Regulatory Actions,
http://www.epa.gov/pm/actions.html.
2 Sections 108-109 of the Clean Air Act (CAA) govern the establishment, review, and revisions of the NAAQS
(42 U.S.C. 7408 and 7409).
3 Section 109(d)(1)) of the CAA.
4 The date completion of the rule was per a June 6, 2012, order issued by the U.S. Court of Appeals for the District of
Columbia Circuit in response to petitions filed by advocacy groups and 11 states, American Lung Ass’n v. EPA,
D.D.C., No. 1:12-cv-243, order issued June 6, 2012, and as agreed to in a September 4, 2012, consent decree, American
Lung Ass’n v. EPA, D.D.C., No. 1:12-cv-243, order signed September 4, 2012. See also U.S. EPA, “Proposed Consent
Decree,” 77 Federal Register 38060, June 26, 2012, http://www.gpo.gov/fdsys/search/pagedetails.action?granuleId=
2012-15603&packageId=FR-2012-06-26&acCode=FR, and American Lung Ass'n v. EPA, D.D.C., No. 1:12-cv-243,
joint motion filed June 5, 2012.
5 EPA published a proposed rule on June 29, 2012, which started a nine-week public comment period that ran through
August 31, 2012, U.S. EPA, National Ambient Air Quality Standards for Particulate Matter, Proposed Rule, 77 Federal
Register 38889-39055, June 29, 2012. The proposal and supporting documents are available on EPA’s website
Particulate Matter (PM): Regulatory Actions, http://www.epa.gov/pm/actions.html. EPA also held two public hearings
for the proposal on July 17, 2012, in Philadelphia, PA, and July 19, 2012, in Sacramento, CA, U.S. EPA, Public
Hearings for Proposed Rules—National Ambient Air Quality Standards for Particulate Matter, 77 Federal Register
39205, July 2, 2012.
6 For information regarding the CASAC PM review panel and its activities and reports, see http://yosemite.epa.gov/sab/
sabpeople.nsf/WebCommittees/CASAC.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
periodic review not long after the 2006 promulgation of the PM NAAQS.8 EPA staff reassessed
scientific studies considered in setting the 2006 PM NAAQS revisions, reviewed and analyzed
extensive subsequent research, and considered public comments and recommendations of the
CASAC. EPA has already initiated the next five-year review of the PM NAAQS.9
Based on the scientific evidence and comments considered, EPA Administrator Lisa P. Jackson
signed the final rule that would change the current standard primarily by lowering the annual
health-based (“primary”) standard for fine particles smaller than 2.5 microns (PM2.5). In the final
rule, the “secondary” standards that provide protection against “welfare” (nonhealth) effects, such
as ecological effects and material deterioration, are identical to the primary standards, the same as
in 2006. The final rule relies on the existing secondary 24-hour standard to protect against
visibility impairment, and did not adopt a separate standard included among options in the June
2012 proposal. Also, as proposed,10 the final rule did not modify the standards for inhalable
“coarse” particles larger than 2.5 but smaller than 10 microns (PM10). Some stakeholders in the
agricultural community and some Members maintained a particular interest in EPA’s
consideration of the PM10 standards and potential impacts that revising the NAAQS may impose
on the agricultural operations.11
In its Regulatory Impact Analysis (RIA) accompanying the final rule assessing the costs and
benefits of proposed revisions to the PM NAAQS, EPA estimated that tightening the PM2.5 annual
standard would add further health benefits beyond those anticipated with the promulgation of the
2006 PM NAAQS.12 Others have suggested that potential health benefits of tightening the PM
NAAQS might be higher than EPA’s estimates.13 On the other hand, tighter standards could
impose additional compliance requirements on communities, states, industry, and others, at what
some stakeholders and Members contend will be a substantial economic cost. EPA expects that
requirements and emission reductions associated with existing and recently promulgated federal
regulations under the CAA will allay impacts of complying with the revised PM standards, and
anticipates that virtually all counties will meet the standards as promulgated in 2020.
(...continued)
7 Section 109(d)(2) of the Clean Air Act.
8 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.
9 U.S. Environmental Protection Agency, “Notice of Workshop and Call for Information on Integrated Science
Assessment for Particulate Matter,” 79 Federal Register 71764, December 3, 2014, http://www.gpo.gov/fdsys/pkg/FR-
2014-12-03/pdf/2014-28278.pdf.
10 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.
11 See CRS Report R41622, Environmental Regulation and Agriculture, coordinated by Megan Stubbs.
12 U.S. EPA, Regulatory Impact Analysis for the Final Revisions to the National Ambient Air Quality Standards for
Particulate Matter, http://www.epa.gov/pm/2012/finalria.pdf. See also U.S. EPA, Regulatory Impact Analysis for the
Proposed Revisions to the National Ambient Air Quality Standards for Particulate Matter, EPA 452/R-12-003, June
2012, http://www.epa.gov/ttn/ecas/regdata/RIAs/PMRIACombinedFile_Bookmarked.pdf. The RIA and supporting
documents are available in the public docket, Docket No. EPA-HQ-OAR-2010-0955, http://www.regulations.gov/
#!searchResults;rpp=25;po=0;s=EPA-HQ-OAR-2010-0955.
13 For an example, see Health Benefits of Alternative PM2.5 Standards, Donald McCubbin, Ph.D., prepared for the
American Lung Association, Clean Air Task Force and Earthjustice, July 2011, http://earthjustice.org/sites/default/
files/Health-Benefits-Alternative-PM2.5-Standards.pdf.
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As per statutory scheduling requirements, on December 18, 2014, EPA classified 14 areas as
“Moderate” nonattainment for the revised 2013 primary annual PM2.5 standard.14 The areas
include 38 counties or portions of counties in six states—California, Idaho, Indiana, Kentucky,
Ohio, and Pennsylvania. EPA also deferred the designation period for 11 other areas (including 2
entire states and all but 3 counties of another) by up to one year, and designated all other areas as
“unclassifiable” or as “unclassifiable/attainment.” The EPA designations will be effective 90 days
after publication in the Federal Register. CAA section 188(c) requires Moderate areas achieve
attainment as expeditiously as practicable, but no later than six years after the effective date final
designation.
Several recent and pending EPA regulations implementing the various pollution control statutes
enacted by Congress garnered vigorous oversight during the 112th Congress.15 Members
expressed concerns in hearings, through bipartisan letters commenting on proposed regulations,
and through introduced legislation that would delay, limit, or prevent certain EPA actions.
Particular attention was focused on EPA’s implementation of the CAA. Because of health and cost
implications, NAAQS decisions historically have been the source of significant concern to some
in Congress.
The evolution and development of the PM NAAQS, in particular, have been the subject of
extensive oversight. During the 112th Congress, some Members expressed concerns in hearings,
letters to the Administrator, and proposed legislation in anticipation of potential changes to the
PM NAAQS, and the January 2013 final rule is expected to generate further oversight. Some
Members16 and industry stakeholders had urged EPA to delay the final rule, while conversely,
others, including some states17 and various environmental and public health advocacy groups,
urged timely completion of a tighter standard. Changes to the NAAQS historically have triggered
litigation alleging the standards are too stringent or not stringent enough, and often resulted in
delays in implementation.
This CRS report summarizes EPA’s January 15, 2013, final and June 2012 proposed changes to
the PM NAAQS and includes comparisons with previous (1997 and 2006) promulgated and
proposed standards. Key actions leading up to the agency’s determination, and potential issues
and concerns associated with changing the PM2.5 annual standard, are also highlighted.18
14 See EPA “Area Designations for the 2012 Annual Fine Particle (PM2.5) Standard: Regulatory Actions” at
http://www.epa.gov/pmdesignations/2012standards/regs.htm.
15 See CRS Report R41561, EPA Regulations: Too Much, Too Little, or On Track?, by James E. McCarthy and Claudia
Copeland.
16 See November 21, 2012, letter from 47 Members of the House of Representatives to the U.S. EPA Administrator,
http://latta.house.gov/uploadedfiles/2012_11_29_final_pm2_5_letter_signed_w_attchmt.pdf. Also see press release
available on Representative Bob Latta’s website at http://latta.house.gov/news/documentsingle.aspx?DocumentID=
314585.
17 See December 6, 2012, letter from nine State Attorneys General to the Acting Administrator of the Office of
Information and Regulatory Affairs, the White House Office of Management and Budget, http://www.eenews.net/
assets/2012/12/10/document_gw_02.pdf.
18 For more information regarding issues and implementation of the PM2.5 NAAQS promulgated in 2006, see CRS
Report RL34762, The National Ambient Air Quality Standards (NAAQS) for Particulate Matter (PM): EPA’s 2006
Revisions and Associated Issues, by Robert Esworthy, and CRS Report R40096, 2006 National Ambient Air Quality
Standards (NAAQS) for Fine Particulate Matter (PM2.5): Designating Nonattainment Areas, by Robert Esworthy.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Background
Particulate matter is one of six “criteria pollutants” for which EPA has promulgated NAAQS
under the CAA.19 The others are ozone (“smog”), nitrogen oxides (NOx),20 sulfur oxides (SOx, or,
specifically, SO2), carbon monoxide (CO), and lead (Pb).
PM2.5 can be emitted directly from vehicles, smokestacks, and fires but can also form in reactions
in the atmosphere from gaseous precursors, including sulfur oxides, nitrogen oxides, and volatile
organics occurring naturally or as emissions typically associated with gasoline and diesel engine
exhaust, and from utility and other industrial processes. PM10 (or coarse PM) is an indicator used
in the NAAQS to provide protection from slightly larger (in the range of 2.5 to 10 microns or
thoracic “coarse” particles), but still inhalable particles that penetrate into the trachea, bronchi,
and deep lungs. These particles are often associated with dust from paved and unpaved roads,
construction and demolition operations (including mining), and sometimes with certain industrial
processes and agriculture operations, as well as biomass burning.
Establishing NAAQS does not directly limit emissions; rather, it represents the EPA
Administrator’s formal judgment regarding the concentration of a pollutant in ambient air that
will protect public health with an “adequate margin of safety.” Under Sections 108-109 of the
CAA,21 Congress mandated that EPA set national ambient (outdoor) air quality standards for
pollutants whose emissions “may reasonably be anticipated to endanger public health (primary
standards) or welfare22 (secondary standards)” and “the presence of which in the ambient air
results from numerous or diverse mobile or stationary sources.” The process for setting and
revising NAAQS consists of the statutory steps incorporated in the CAA over a series of
amendments. Several other steps have also been added by EPA, by executive orders, and by
subsequent regulatory reform enactments by the Congress.
Section 109(d)(1)) of the CAA requires EPA to review the criteria that serve as the basis for the
NAAQS for each covered pollutant every five years, to either reaffirm or modify previously
established NAAQS. Prior to the January 2013 revisions, EPA has revised the PM NAAQS three
times, in 1987, 1997, and October 2006, to ensure that the standards continue to provide adequate
protection for public health and welfare.23
A February 24, 2009, decision by the U.S. Court of Appeals for the District of Columbia Circuit
had remanded elements of EPA’s decisions as promulgated in October 2006, in particular the
decision not to tighten the primary annual NAAQS for PM2.5, to the agency for further
19 42 U.S.C. 7408(a)(1).
20 The NAAQS is for NO2; nitrogen gases that are ozone precursors are referred to as NOx.
21 42 U.S.C. 7408(a)(1).
22 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)).
23 Beginning in 1971, regulation and monitoring of particulate matter under the CAA focused primarily on total
suspended particles (TSP) and, eventually in 1987, on coarse particles equal to or less than 10 micrometers in diameter
(PM10). EPA revised the particulates standards in 1997 to provide separate requirements for fine particulate matter
(PM2.5). See EPA’s “Particulate Matter (PM) Standards—Table of Historical PM NAAQS” at http://www.epa.gov/ttn/
naaqs/standards/pm/s_pm_history.html.
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consideration but did not vacate the revised standard nor set a specific timeline. The decision was
in response to petitions filed in the D.C. Circuit by 13 states, industry, agriculture, business, and
environmental and public health advocacy groups, challenging certain aspects of EPA’s revisions
for both PM2.5 and PM10. The D.C. Circuit granted the petitions in part with regard to the PM2.5
annual standard and the secondary standards for PM2.5 and PM10 (including visibility impairment),
denying other challenges.24
Concerned with delays in EPA’s schedule for proposing revisions to the 2006 PM NAAQS, the
American Lung Association and the National Parks Conservation Association, and nine states
separately filed petitions with the D.C. Circuit in November 2011 urging the court to order EPA’s
immediate compliance with the February 2009 remand. Subsequently, in February 2012 the two
organizations sued EPA in the D.C. Circuit for failing to fulfill their statutory duty to review the
October 2006 PM NAAQS within five years,25 and a coalition of 11 states filed a similar suit with
the U.S. District Court Southern District of New York.26 In response, the D.C. Circuit initially
directed EPA to sign a proposed rule concerning its decision regarding revisions to the PM
NAAQS by June 7, 2012, and following a motion filed by the agency, amended the deadline to
June 14, 2012.27 As part of a September 4, 2012, consent decree, EPA agreed to finalize revisions
to the PM NAAQS by December 14, 2012.28
Promulgation of a revised NAAQS, such as the PM NAAQS, initiates a series of statutorily
required actions, ultimately culminating in issuance of permits pursuant to state regulations in a
State Implementation Plan (SIP). The first step is designation of attainment and nonattainment
areas, based on the accumulated results of ambient air monitoring and modeling data. States first
propose to designate certain geographic areas (e.g., counties) as either “attainment” or
“nonattainment,” depending on whether the data indicate the concentrations of pollutants will be
below or above the NAAQS. After extensive dialogue with state officials, EPA either approves
the proposed attainment and nonattainment areas, or sends back to states proposed revisions. EPA
and states generally come to an agreement about the area designations. Following this
designation, approved by EPA, states then develop a SIP, which consists essentially of state
regulations to be implemented by states that would affect the state emissions inventory, and
therefore the expected or modeled concentrations of air pollutants. After approval of the SIP as
being adequate to control air pollution and reduce the ambient air pollutant concentrations in
designated nonattainment areas, the states then issue permits (new or modified) for facilities
whose emissions affect the air in designated nonattainment areas.
24 For a more detailed discussion regarding the petitions see section entitled “Petitions Challenging the 2006 PM
NAAQS and the D.C. Circuit’s February 29, 2009, Decision” 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.
25 American Lung Ass’n v. EPA, D.D.C., No. 1:12-cv-243, filed February 14, 2012.
26 States of New York, California, Connecticut, Delaware, Maryland, New Mexico, Oregon, Rhode Island, Vermont,
and Washington, and Commonwealth of Massachusetts v. EPA, D.S. N.Y., 12 CIV 1064, filed February 10, 2012,
http://www.atg.state.vt.us/assets/files/NY%20v%20EPA%20Complaint%20(2-10-12).pdf.
27 See footnote 4.
28 See footnote 5.
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EPA’s January 2013 Final Changes to the
PM NAAQS
EPA’s 1997 revisions to the PM NAAQS29 revised the standards focused on particles smaller than
10 microns (PM10 or coarse particles) established in 1987,30 and introduced standards for “fine”
particles smaller than 2.5 microns (PM2.5) for the first time. The primary (health protection) PM
NAAQS as revised in 2006 include an annual and a daily (24-hour) limit for PM2.5, but only a
daily limit for PM10. To attain the PM2.5 annual standard, the three-year average of the weighted
annual arithmetic mean PM2.5 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,31 indicating the percent of the time that a monitoring station can exceed the standard. For
instance, a 98th percentile 24-hour standard indicates that a monitoring station can exceed the
standard 2% of the time during the year. For PM2.5 and PM10, the secondary NAAQS, which are
set at a level “requisite to protect the public welfare,” are the same as the primary standards.
In the final rule published by EPA on January 15, 2013, the PM2.5 and PM10 standards and other
implementation changes are as follows:32
Primary (Public Health) PM Standards
• PM2.5: EPA revised the annual standard, which currently is 15 micrograms per
cubic meter (µg/m3), by setting a new limit of 12 µg/m3 (the proposal included an
optional limit of 13 µg/m3 and solicited comment for 11 µg/m3); compliance with
the “annual” standard is determined by whether the three-year average of its
annual average PM2.5 concentration (at each monitoring site in the area) is less
than or equal to 12 µg/m3; as proposed, EPA retained the daily (24-hour) standard
at 35 µg/m3 based on the current three-year average of the 98th percentile of 24-
hour PM2.5 concentrations as established in 2006.
• PM10: As proposed, EPA retained the current daily standard of no more than one
exceedance of concentrations of 150 µg/m3 per year on average over three years;
there is no current annual standard for PM10 (the previous annual maximum
concentration standard of 50 µg/m3 was eliminated by EPA in 2006).33
Secondary (Welfare) PM Standards
• PM2.5 and PM10: As proposed, secondary (welfare) NAAQS are the same as the
primary standards, the same correlations as the 2006 PM NAAQS, with the
exception of visibility impairment associated with PM2.5.
29 62 Federal Register 38652-38896, July 18, 1997.
30 PM10 NAAQS were promulgated in 1987, 52 Federal Register 24640, July 1, 1987.
31 “The “form” of a standard defines the air quality statistic that is to be compared to the level of the standard in
determining whether an area attains that standard.” 77 Federal Register 38954, June 29, 2012.
32 See footnote 1.
33 Based on the 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.
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• PM2.5 Visibility Impairment: The final rule did not add a distinct secondary
standard as proposed, defined in terms of a PM2.5 visibility index based on
speciated34 PM2.5 mass concentrations and relative humidity data to calculate
light extinction on a deciview (dv) scale35 similar to the current Regional Haze
Program.36 Specifically, the proposal would have set a 24-hour averaging time of
30 or 28 deciviews (dv) based on a 90th percentile form over three years. EPA
also sought comment on alternative levels (down to 25 dv) and averaging times
(e.g., 4 hours). Based on public comment and further analysis of air quality
monitoring data, EPA concluded that the current secondary standard would
provide visibility protection greater than or equal to 30 dv.37
Implementation Changes
• Monitoring:38 As proposed, updates several aspects of monitoring regulations
including requiring relocating a small number of PM2.5 monitors39 to be
collocated with measurements of other criteria pollutants (e.g., nitrogen dioxide
(NO2) and carbon monoxide (CO)) near-roadway monitoring so as to ensure
these monitors are at one location in each urban area with a population of 1
million or more, and to be phased in starting with the largest areas (2.5 million or
more populations) by January 1, 2015, and extended to the remainder of areas by
January 1, 2017. Includes the use data from existing Chemical Speciation
Network or the EPA/National Park Service IMPROVE monitoring network to
determine whether an area meets the proposed secondary visibility index
standard for PM2.5. No changes to PM10 monitoring.
• Air Quality Index (AQI): As proposed, updates the AQI (EPA’s color-coded tool
for informing the public about air quality and associated measures for reducing
risks of exposure) for PM2.5 by changing the upper end range for “Good”
category (an index value of 50) on the overall scale (0 to 500 based on
conversion of PM2.5 concentrations) to the level of the revised annual PM2.5
standard (12 µg/m3). Also as proposed, EPA is setting the 100 value of the index
scale (“Moderate”) at the level of the current 24-hour PM2.5 standard, which is 35
µg/m,3 and the AQI of 150 (“Unhealthy Sensitive Groups”) at 55 µg/m3. The
34 Includes a measure of PM2.5 mass, elements, ions, and carbon species. See EPA’s laboratory standard operating
procedures (SOPs) for PM2.5 chemical speciation at http://www.epa.gov/ttnamti1/specsop.html.
35 “The deciview scale is frequently used in the scientific and regulatory literature on visibility. This metric describes
changes in uniform light extinction that can be perceived by a human observer. One deciview represents the minimal
perceptible change in visibility to the human eye,” 77 Federal Register 39043, June 29, 2012. A “deciview is a
yardstick for measuring visibility: the higher the deciview level, the hazier the air appears,” U.S. EPA, Fact Sheet:
Revised Air Quality Standards for Particle Pollution and Updates to the Air Quality Index (AQI), http://www.epa.gov/
pm/2012/decfsstandards.pdf.
36 See U.S. EPA, “EPA’s Regional Haze Program,” http://www.epa.gov/visibility/program.html.
37 See footnote 35.
38 See EPA Fact Sheet: EPA’s Revised Air Quality Standards for Particle Pollution: Monitoring, Designations and
Permitting Requirements, http://www.epa.gov/pm/2012/decfsimp.pdf. See also EPA Fact Sheet: EPA’s Proposal to
Update the Air Quality Standards for Particle Pollution: Monitoring, Designations and Permitting Requirements,
http://www.epa.gov/airquality/particlepollution/2012/fsimp.pdf.
39 EPA indicated that it is not increasing the size of the current PM2.5 monitoring network of about 900 monitors, but
anticipates that states will be able to relocate roughly 52 existing monitors to meet the near-roadway requirement; see
previous footnote.
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current upper ends for the “Hazardous” (500), “Unhealthy” (200) and “Very
Unhealthy” (300) AQIs are retained.40
• Prevention of Significant Deterioration (PSD):41 EPA revised the PSD
permitting program (rules) with respect to the revised PM NAAQS so as not to
“unreasonably delay” pending permits and establish a “grandfather” provision for
permit applications if: the permitting agency deems an application complete by
December 14, 2012; or public notice for a draft permit or preliminary
determination has been published (for public comment) no later than the effective
date of revised PM NAAQS (60 days after January 15, 2013, publication in the
Federal Register). This provision would not apply to NAAQS for other criteria
pollutants and permits not meeting these criteria would have to demonstrate
compliance with the revised standards once they are finalized.
Comparison of the January 2013 Revised PM2.5 Standards with
Previous Promulgated and Proposed Alternative PM Standards
The final PM2.5 daily standard established in 2006 was among the less stringent within the range
of alternative levels recommended by EPA staff, and the annual standard is not as stringent as the
standard recommended by the CASAC. The decision to retain the annual PM2.5 standard was also
less than recommended. Table 1 below shows the January 2013 revised PM2.5 annual standard in
comparison to the June 2012 proposed options and to the annual and daily standards for 1997 and
2006 promulgated standards, and alternative levels recommended prior to the 2006 final
revisions.
40 U.S. EPA, Fact Sheet: See EPA Fact Sheet: Revised Air Quality Standards for Particle Pollution and Updates to the
Air Quality Index (AQI), http://www.epa.gov/pm/2012/decfsstandards.pdf. See also EPA Fact Sheet: Summary of
Proposed Improvements to the Air Quality Standards for Particle Pollution and Updates to the Air Quality Index
(AQI), http://www.epa.gov/pm/pdfs/PMNAAQSProposalSTANDARDSAQI61412FINALUPDATED.pdf.
41 See footnote 38.
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Table 1. Promulgated, Proposed, and Alternative PM2.5 Primary (Health) National
Ambient Air Quality Standards (NAAQS)
PM2.5 NAAQS Options
24-hour Primary
Annual Primary
micrograms per cubic meter = µg/m3
1997 Promulgated PM NAAQS
65 µg/m3 15
µg/m3
CASAC Recommendation (June 2005)
35-30 µg/m3 14-13
µg/m3
EPA Final “Staff Paper” (Dec. 2005)
35-25 µg/m3 15
µg/m3
or
40-30
µg/m3 14-12
µg/m3
Dec. 2005 Proposed PM NAAQS Rule
35 µg/m3 15
µg/m3
2006 Promulgated PM NAAQS
35 µg/m3 15
µg/m3
CASAC Recommendation (August 2010)
35-30 µg/m3 13-11
µg/m3
EPA Final “Staff Paper” (April 2011)
35-30 µg/m3 13-11
µg/m3
2012 Proposed Rule (June 2012)
35 µg/m3 13-12
µg/m3 (EPA also
solicited comments for
a limit of 11 µg/m3)
January 15, 2013, Final Rule
35 µg/m3 12
µg/m3
Source: Prepared by the Congressional Research Service (CRS) with information from EPA’s January 15, 2013,
final rule and June 2012 proposal and related technical documents, and the December 2006 promulgated PM
NAAQS and supporting technical and policy documents (http://www.epa.gov/air/particles/actions.html).
Note: PM2.5 = “fine” particulate matter 2.5 micrometers or less in diameter.
Review Process Leading Up to the
January 2013 Revised PM NAAQS
The CAA as enacted includes specific requirements for a multistage process to ensure the
scientific integrity under which NAAQS are set, laying the groundwork for the Administrator’s
determination of the standard, and the procedural process for promulgating the standard.42
Primary NAAQS, as described in Section 109(b)(1), were to be “ambient air quality standards the
attainment and maintenance of which in the judgment of the Administrator, based on such criteria
and allowing an adequate margin of safety, are requisite to protect the public health.”
Based on this premise, the CAA specifies the criterion to be used by the Administrator in deciding
on the final standard, including preparation of a “criteria document” that summarizes scientific
information assessed. The act also requires the establishment and role of an independent advisory
committee (CASAC)43 to review EPA’s supporting scientific documents, and the timeline for
completing specific actions. EPA administratively added the preparation of a “staff paper” that
summarizes the criteria document and lays out policy options. This EPA document typically
42 For a detailed overview of the NAAQS process see CRS Report 97-722, Air Quality Standards:
The Decisionmaking Process.
43 For general information regarding the CASAC as well as the CASAC panel for the PM NAAQS review, see EPA
Clean Air Advisory Committee (CASAC) website http://yosemite.epa.gov/sab/sabpeople.nsf/WebCommittees/CASAC.
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serves as the basis for CASAC review and comment. EPA revised certain aspects (not including
reinstating the closure letter) of the CASAC review process most recently in May 2009.44 In
addition, Executive Order 12866 requires a Regulatory Impact Analysis (RIA), although the
economic impact analysis is essentially only for informational purposes and cannot be directly
considered as part of the decision in determining the NAAQS.45
Beginning June 2007 with its general call for information,46 EPA initiated the current PM
NAAQS review, which culminated in assessments of the scientific research and risk analyses, and
ultimately the April 2011 publication of the staff’s final Policy Assessment for the Review of the
Particulate Matter National Ambient Air Quality Standards (or PM Policy Assessment).47 The
staff paper presented the staff conclusions and recommendations on the elements of the PM
standard based on evaluation of the policy implications of the scientific evidence contained in the
criteria document and the results of quantitative analyses (e.g., air quality analyses, human health
risk assessments, and visibility analyses) of that evidence. Table B-1 in Appendix B provides a
chronological listing of EPA’s supporting documents leading up to the June 2012 proposed PM
NAAQS.
Supplemental to public comments solicited in the Federal Register, the CASAC reviewed EPA’s
drafts and final documents supporting the science and policy behind the Administrator’s decisions
in the June 2012 PM NAAQS proposal. The CASAC conducted meetings and consultations, and
submitted written overviews, providing their views of the validity and completeness of the
agency’s assessments and findings, and recommending improvements. CASAC’s final product,
its review of EPA’s second external review draft of the “PM Policy Assessment,” was completed
June 2010.48
Table B-2 in Appendix B provides a chronological summary of CASAC consultations and
reviews of the supporting documents for the June 2012 proposal.
44 For EPA’s most recent revisions to the CASAC review process, see the May 21, 2009, memorandum from
Administrator Lisa P. Jackson to Dr. Jonathan Samet, CASAC Chair, and to Elizabeth Craig, Acting EPA
Administrator for Air and Radon, and Lek Kadeli, Acting Administrator for Research and Development,
http://yosemite.epa.gov/sab/sabproduct.nsf/WebCASAC/NewNAAQSProcess?OpenDocument.
45 The CAA directs the EPA Administrator to protect public health with an adequate margin of safety. This language
has been interpreted, both by the agency and by the courts, as requiring standards based on a review of the health
impacts, without consideration of the costs, technological feasibility, or other nonhealth criteria. Costs and feasibility
are generally taken into account in NAAQS implementation (a process that is primarily a state responsibility).With
regard to the nonrelevance of cost considerations, see generally Whitman v. American Trucking Associations, 531 U.S.
457, 465-472, 475-76 (2001).
46 U.S. EPA, “Integrated Science Assessment for Particulate Matter: Call for Information,” 72 Federal Register 35462,
June 28, 2007.
47 U.S. EPA, Policy Assessment for the Review of the Particulate Matter National Ambient Air Quality Standards, 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.
48 Until discontinued by the CASAC Chairman in 2005, CASAC historically had signed off in the form of a “closure
letter” only when the panel of members was convinced that each document accurately reflected the status of the
science. The CASAC closure letter was an indication that the majority of the CASAC panel members had generally
reached consensus that the criteria documents and the staff paper provided an adequate scientific basis for regulatory
decision making. The discontinuance of the closure letter was the subject of considerable debate, particularly within the
science community. See CRS Report RL33807, Air Quality Standards and Sound Science: What Role for CASAC?, by
James E. McCarthy.
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The April 2011 EPA policy assessment (“staff paper”) concluded, and the CASAC panel
concurred in its final recommendations, that the scientific evidence supported modifying the
PM2.5 primary standard and considering options for revising the secondary standard for reducing
visibility impairment associated with PM. Recognizing certain limitations of the data, the policy
assessment included a range of alternatives for consideration by the Administrator for modifying
the current PM NAAQS. These recommendations were the core basis for the June 2012
proposal49 and the Administrator’s final decision to revise the PM NAAQS, taking into account
other factors including public comments received in response to the June 2012 proposal.
The EPA staff paper included possible modifications to strengthen certain aspects of the PM10
standard. However, staff and CASAC placed considerable emphasis on continuing uncertainties
and lack of sufficient data to initiate relevant quantitative risk assessment to support such
modifications to the standard. As presented in the June 2012 Federal Register notice, the
Administrator provisionally concluded that the growing evidence continued to support the
appropriateness of the existing primary 24-hour PM10 standard’s protection of short-term health
effects, and proposed to retain the existing PM10 standard.50
A perennial issue in conducting NAAQS reviews is whether the agency is basing its decisions on
those studies that reflect the latest science, and that the scientific basis is rigorous and unbiased.
In reviewing thousands of studies, the agency staff ultimately needs to establish a cutoff date, or
be faced with the need for a continuous review. The current review was based on studies
completed by mid-2009, but in the June 29, 2012, Federal Register notice EPA indicated that it
is aware that a number of new scientific studies on the health effects of PM have been
published since the mid-2009 cutoff date for inclusion in the Integrated Science Assessment.
As in the last PM NAAQS review, the EPA intends to conduct a provisional review and
assessment of any significant new studies published since the close of the Integrated Science
Assessment, including studies that may be submitted during the public comment period on
this proposed rule in order to ensure that, before making a final decision, the Administrator is
fully aware of the new science that has developed since 2009. In this provisional assessment,
the EPA will examine these new studies in light of the literature evaluated in the Integrated
Science Assessment. This provisional assessment and a summary of the key conclusions will
be placed in the rulemaking docket.51
Publication of the proposed PM NAAQS rule in the Federal Register on June 29, 2012,52 started
a nine-week public comment period that ran through August 31, 2012. EPA also held two public
hearings for the proposal on July 17, 2012, in Philadelphia, PA, and July 19, 2012, in Sacramento,
CA.53 EPA’s final determinations for revising the PM NAAQS published on January 15, 2013,
49 See 77 Federal Register 38900-38944, Section III. Rationale for Proposed Decisions on Primary PM2.5 Standards,
June 29, 2012.
50 See 77 Federal Register 38944-38963, Section IV. Rationale for Proposed Decisions on Primary PM10 Standards,
June 29, 2012.
51 See 77 Federal Register 38899, Section II. Background (B) Review of the Air Quality Criteria and Standards for PM
(3) Current PM NAAQS Review, June 29, 2012.
52 U.S. EPA, National Ambient Air Quality Standards for Particulate Matter, Proposed Rule, 77 Federal Register
38889-39055, June 29, 2012. The proposal as signed by EPA Administrator Lisa P. Jackson on June 14, 2012 and
supporting documents are available on EPA’s website Particulate Matter (PM): Regulatory Actions,
http://www.epa.gov/pm/actions.html.
53 U.S. EPA, Public Hearings for Proposed Rules—National Ambient Air Quality Standards for Particulate Matter,
77 Federal Register 39205, July 2, 2012.
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were based on information provided in the two public hearings, the more than 230,000 written
public comments received, and EPA’s consideration of and analysis in response to this
information. EPA also revised its Regulatory Impact Analysis (RIA),54 in large part in response to
comments received.
Implementing the Revised PM2.5 NAAQS
Promulgation of NAAQS sets in motion a process under which the states and EPA first identify
geographic nonattainment areas, those areas failing to comply with the NAAQS based on
monitoring and analysis of relevant air quality data.55 The CAA is specific with regard to the
timelines for determining areas in noncompliance, submission of plans for achieving (or
maintaining) compliance, and when noncompliant areas must achieve the established or revised
NAAQS.
Typically, within three years of issuance of a NAAQS, states are required to submit
“infrastructure” plans demonstrating that they have the basic air quality management components
necessary to implement the NAAQS.56 Following states’ proposed and EPA’s final designations of
attainment and nonattainment areas, states (and tribes if they choose to do so) must submit their
plans (State Implementation Plans, or SIPs) for how they will achieve and/or maintain attainment
of the standards. These often include new or amended state regulations and new or modified
permitting requirements.
If new, or revised, SIPs for attainment establish or revise a transportation-related emissions
allowance (“budget”), or add or delete transportation control measures, they will trigger
“conformity” determinations. Transportation conformity is required by the CAA, Section 176(c)
(42 U.S.C. 7506(c)), to prohibit federal funding and approval for highway and transit projects
unless they are consistent with (“conform to”) the air quality goals established by a SIP, and will
not cause new air quality violations, worsen existing violations, or delay timely attainment of the
national ambient air quality standards.57
Areas designated nonattainment, as well as those designated unclassifiable or
unclassifiable/attainment for the NAAQS, are also 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
54 For key components of the revised RIA see “Important Updates and Analytic Differences Between the PM NAAQS
Proposal RIA and the Final RIA,” Section ES.5 p. ES-23 of the December 2012 RIA, http://www.epa.gov/pm/2012/
finalria.pdf.
55 For a general overview of the NAAQS designations process, see EPA’s “Designations” website at
http://www.epa.gov/air/urbanair/designations.html.
56 Section 110(a)(2) of the Clean Air Act. For a general overview of the NAAQS implementation plans process, see
EPA’s “State Implementation Plan Overview” website at http://www.epa.gov/air/urbanair/sipstatus/overview.html.
57 On March 14, 2012, EPA published a final rule restructuring sections of the conformity rule so that existing
requirements apply to new or revised NAAQS and released associated implementation guidance July 2012. (U.S. EPA,
Office of Transportation and Air Quality, Guidance for Transportation Conformity Implementation in Multi-
Jurisdictional Nonattainment and Maintenance Areas, July 2012, http://www.epa.gov/otaq/stateresources/transconf/
regs/420b12046.pdf). For transportation conformity regulations see, U.S. EPA “State and Local Transportation
Resources: Transportation Conformity” at http://www.epa.gov/otaq/stateresources/transconf/index.htm.
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provisions outline permitting requirements both for construction of new major pollution sources
and for modifications to existing major pollution sources.58 The specific NSR requirements for
affected sources depend on whether the sources are subject to “Prevention of Significant
Deterioration” (PSD) or nonattainment provisions.59 As discussed earlier (see “EPA’s January
2013 Final Changes to the PM NAAQS”), the January 2013 final PM NAAQS includes revisions
to the PSD permitting program (rules) with respect to the revised PM NAAQS so as not to
“unreasonably delay” pending permits and establish a “grandfather” provision for permit
applications if a draft permit or preliminary determination has been issued for public comment by
the date the revised PM NAAQS go into effect.
In addition to the CAA requirement for states to submit implementation plans, EPA acts to control
NAAQS pollutants through national regulatory programs. These may be in the form of
regulations of products and activities that might emit the pollutants (particularly fuels and
combustion engines, such as automobiles and trucks) and in the form of emission standards for
new stationary sources (e.g., utilities, refineries). Often these national regulations reflect aspects
of state rules previously issued by various states. EPA anticipates that recent CAA rules, including
rules to reduce pollution from power plants, clean diesel rules for vehicles, and rules to reduce
pollution from stationary diesel engines, would help states meet the revised PM NAAQS.
Nonattainment Area Designation Process
The process of designating nonattainment areas is intended as a cooperative federal-state-tribal60
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/unclassifiable”61 when they meet the standard or when the data are insufficient for
determining compliance with the NAAQS.
Following state and tribal recommended designation submissions, the EPA Administrator has
discretion to make modifications, including to the area boundaries. As required by statute
(Section 107(d)1(B)(ii)), the agency must notify the states and tribes regarding any modifications,
allowing them sufficient opportunity to demonstrate why a proposed modification is
inappropriate, but the final determination rests with EPA.
58 For an overview, including statutory authority and regulations, see EPA’s “New Source Review (NSR)” at
http://www.epa.gov/air/nsr/.
59 See Clean Air Act, Part D—Plan Requirements for Nonattainment Areas, sections 171-178, codified at 40 CFR
52.24(f)(10). Section 166 of the CAA authorizes EPA to establish regulations for PSD of any pollutant for which EPA
has issued a national standard.
60 Though not required, tribes have been encouraged to submit recommendations. The area designation requirements
under the CAA (Section 107) are specific with respect to states, but not to tribes. EPA follows the same designation
process for tribes per Sections 110(o) and 301(d) of the CAA and pursuant to the 1988 Tribal Authority Rule, which
specifies that tribes shall be treated as states in selected cases (40 CFR Part 49). For information regarding tribes that
have participated in the PM2.5 designation recommendation process, see http://www.epa.gov/pmdesignations.
61 Section 107(d)(1)(A)(iii) of the CAA provides that any area that EPA cannot designate on the basis of available
information as meeting or not meeting the standards should be designated unclassifiable.
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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.62 EPA began
developing methods for monitoring fine particles at the time the PM2.5 NAAQS were being
finalized in 1997, and operation of the network of monitors for PM2.5 was phased in from 1999
through 2000. The network of monitors and their locations have been modified over time. Most
recently, in a separate action in conjunction with the October 2006 publication of the revised
particulates NAAQS, EPA amended its national air quality monitoring requirements, including
those for monitoring particle pollution.63 The amended monitoring requirements were intended to
help federal, state, and local air quality agencies by adopting improvements in monitoring
technology. Additional modifications to the PM NAAQS monitoring network were included in
the final January 2013 rule, as discussed earlier in this report.
In addition to air emission and air quality data, EPA considers a number of other relevant factors
when designating nonattainment areas,64 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.
January 2013 Final Revised PM2.5 Annual NAAQS: Area Designations
The January 2013 final rule revising the PM2.5 annual standard, as expected, resulted in an
increased number of areas (typically defined by counties or portions of counties) designated
nonattainment. Similar to the revisions to the PM2.5 daily (24-hour) standard in 2006, the January
2013 revised concentrations for the PM2.5 annual standard are expected to affect primarily areas
currently in nonattainment for the 2006 standards, but also included counties that have not been
previously designated as nonattainment. EPA did not require new nonattainment designations for
the PM2.5 24-hour standard or the PM10 primary NAAQS since the standards were not changed in
the January 2013 final rule.
62 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).
63 Revisions to Ambient Air Monitoring Regulations, final rule, 71 Federal Register 61235-61328, October 17, 2006.
http://www.epa.gov/air/particlepollution/actions.html.
64 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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Section 107(d)(1) of the CAA requires states to submit area designation recommendations no
later than one year following the promulgation of a NAAQS standard. For the 2013 PM NAAQS,
state recommendations were due by December 13, 2013.65 The CAA requires EPA to make its
final area designations within one year of the state and tribal recommendations. EPA is required
to notify states and tribes of its intended modifications to their recommendations 120 days prior
to promulgating final designations. EPA responded to the states with its proposed modifications to
their area designation recommendations for the 2013 PM2.5 NAAQS for the annual standard in
letters on or about August 19, 2014.66 As per the CAA, states were provided the opportunity to
submit additional relevant information to demonstrate why EPA’s modifications to the states’
recommendations are inappropriate prior to the agency’s final designations.67
On December 18, 2014, EPA announced the final area designations, classifying 14 areas as
nonattainment for the revised 2013 primary annual PM2.5 standard.68 The areas include 38
counties or portions of counties in six states—California, Idaho, Indiana, Kentucky, Ohio, and
Pennsylvania. Figure 1 presents the final nonattainment area counties (portions of counties are
depicted as whole counties), identifying those counties that were previously designated
nonattainment for the 1997 or 2006 PM2.5 NAAQS, and those not previously designated. EPA
also deferred the designation period for 11 other areas composed of 2 entire states (Florida and
Tennessee, excluding 3 counties), and 24 counties in three states (Alabama, Georgia, and South
Carolina) by up to one year. All other areas of the country (including the District of Columbia,
Tribes, and Territories in addition state counties) were designated as “unclassifiable” or as
“unclassifiable/attainment.”69
In accordance with a January 4, 2014, decision by the Circuit Court of the District of Columbia,70
EPA classified all nonattainment areas as “Moderate” under section 188(a) of Subpart 4 of Title I
65 States, as well as the District of Columbia, and certain Tribes and Territories, provided their recommendations to
EPA by November 2013 ( a subset of states submitted revisions in July 2014); see “EPA Area Designations for the
2012 Annual Fine Particle (PM2.5) Standard: State Recommendations and EPA Responses for Area Designations,”
http://www.epa.gov/pmdesignations/2012standards/staterec.htm. For fact sheets and other information regarding EPA’s
August 19, 2014 intended designations, see “Area Designations for the 2012 Annual Fine Particle (PM2.5) Standard:
Regulatory Actions” at http://www.epa.gov/airquality/particlepollution/designations/2012standards/index.htm.
66 EPA’s intended area designations were based on more current monitoring data (2011-2013) and several other factors.
See “EPA Area Designations for the 2012 Annual Fine Particle (PM2.5) Standard: State Recommendations and EPA
Responses for Area Designations,” http://www.epa.gov/pmdesignations/2012standards/staterec.htm, and EPA “Area
Designations for the 2012 Annual Fine Particle (PM2.5) Standard: Regulatory Actions” at http://www.epa.gov/
pmdesignations/2012standards/regs.htm.
67 The EPA August 2014 response letters for all states with areas intended designated nonattainment urged states to
submit “additional information for the EPA to consider” by October 29, 2014. Several states, including all those with
areas EPA intended to designate nonattainment, submitted their responses to the EPA’s August 2014 proposed
designations by the October 2014 deadline. See footnote 66.
68 See EPA “Area Designations for the 2012 Annual Fine Particle (PM2.5) Standard: Regulatory Actions,”
http://www.epa.gov/pmdesignations/2012standards/regs.htm; see also “Area Designations for the 2012 National Air
Quality Standard for Fine Particles: Initial Designations for States and Territories,” http://www.epa.gov/
pmdesignations/2012standards/state.htm.
69 For an inactive map showing the state by state initial “moderate” nonattainment designations see EPA’s website
“Area Designations for the 2012 Annual Fine Particle (PM2.5) Standard: Regulatory Actions” at http://www.epa.gov/
airquality/particlepollution/designations/2012standards/index.htm.
70 Natural Resources Defense Council and Sierra Club v. EPA, No. 08-1250 (D.C. Cir. January 4, 2013). See also EPA
Particulate Matter Regulatory Actions: Summary of January 4, 2013, Court Decision, http://epa.gov/pm/2013/
20130104dcdecision.pdf.
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of the CAA as specified in its April 2013 area designation guidance for states.71 EPA may
reclassify as “Serious” those nonattainment areas that EPA determines cannot practicably attain
the PM2.5 NAAQS by the applicable attainment date, or if the agency determines that any area has
not in fact attained the PM2.5 NAAQS after each area’s applicable attainment date has passed.
EPA had previously implemented the PM2.5 NAAQS, including nonattainment determinations for
the 1997 and 2006 revisions, under the general implementation provisions in Subpart 1 of Part D
of Title I of the act. However, in the January 4, 2013 decision, the Circuit Court of the District of
Columbia determined that EPA had erred in implementing the PM2.5 NAAQS under Subpart 1,
and required the Agency to implement the PM2.5 NAAQS under Subpart 4.
Figure 1. EPA December 2014 Counties Designated Nonattainment for 2013 PM2.5
NAAQS Compared to Their Final Designations for 2006 and 1997 PM2.5 NAAQS
(violating the 2013 annual standard (12 μg/m3), compared to 1997 annual standard (15 μg/m3),
and/or the 2006 24-hour standard (35 μg/m3)
Source: Prepared by the Congressional Research Service with data compiled from EPA’s website for PM
designations http://www.epa.gov/pmdesignations/. Nonattainment counties for the 2013 PM2.5 annual standard
are based on EPA’s final designations announced December 18, 2014; previously designated nonattainment
counties for the annual standard are based on the October 2006 final area designations for the 1997 PM2.5
NAAQS; previously designated nonattainment counties for the 24-hour standard are based on EPA’s November
2009 final designations for the 2006 PM2.5 NAAQS.
Notes: Partial counties are shown on the map as whole counties. EPA’s December 2014 final designations did
not include any counties or partial counties in Alaska or Hawaii.
71 See p. 6 of 34 of EPA’s “April 2013 Guidance for Area Designations for the 2012 Annual PM2.5 NAAQS,”
http://www.epa.gov/pmdesignations/2012standards/docs/april2013guidance.pdf.
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The 2006 revisions to the PM NAAQS tightening the 24-hour standard, which are currently being
implemented, primarily affected urban areas. 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, on November 13, 2009.72 Based on
the 2009-2011 data, 28 of the 120 counties designated nonattainment for the 2006 PM 24-hour
standard would be in nonattainment for the January 2013 annual standard. The designations,
based on 2006 through 2008 air quality monitoring data, included a few counties that were
designated nonattainment for PM2.5 for the first time, but the majority of the counties identified
overlapped with EPA’s final nonattainment designations for the 1997 PM2.5 NAAQS.73 It is
important to note that most of the 1997 PM2.5 nonattainment areas were only exceeding the annual
standard; thus, tightening 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 standard. The
majority of the roughly 3,000 counties throughout the United States (including tribal lands) were
designated attainment/unclassifiable, and are not required to impose additional emission control
measures to reduce PM2.5.
State Implementation Plans (SIPs)
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. Areas designated as 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 2013 PM2.5 annual standard. These plans are defined as State Implementation Plans,
and referred to as SIPs (TIPs for tribal implementation plans).
As discussed previously in this CRS report, all initial nonattainment area designations for the
2013 PM2.5 annual standard will be classified by EPA as Moderate as provided under Subpart 4 of
Part D of Title I of the CAA (section 188(a)), not under the general implementation provisions in
Subpart 1 of the act. For the most part, the Subpart 4 SIP requirements for areas classified as
Moderate are comparable to those of Subpart 1. However, under Subpart 4 states have 18 months
from the date of EPA’s final designations to submit SIPs.74 Implementing the PM2.5 NAAQS
under Subpart 1 required submission of SIPs three years from the date of EPA’s final
designations. The EPA Moderate nonattainment designations for the 2013 PM2.5 NAAQS will be
effective 90 days after publication in the Federal Register; thus EPA anticipates that states will
need to submit their plans by fall of 2016.75
72 74 Federal Register 58688-58781, November 13, 2009; see also “Area Designations for 2006 24-Hour Fine
Particulate (PM2.5) Standards—Regulatory Actions,” http://www.epa.gov/pmdesignations/2006standards/regs.htm#4.
Publication of a final area designation rule for the 2006 24-hour PM2.5 NAAQS had been delayed as a result of the
incoming Administration’s review of the final rule, along with several other agency proposed and final actions
introduced toward the end of the previous Administration. See footnote 66.
73 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.
74 Part D of title I of the CAA (§189(a)(2)(B)).
75 See EPA’s Fact Sheet “Final Area Designations for the Annual Fine Particle Standard Established in 2012,”
http://www.epa.gov/pmdesignations/2012standards/final/20141218fs.pdf.
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Under Subpart 4,76 EPA may reclassify as “Serious” any nonattainment area that the agency
determines cannot practicably attain the PM2.5 NAAQS by the applicable attainment date or those
areas classified as Moderate that do not attain the PM2.5 NAAQS after their applicable attainment
date has passed. Subpart 4 introduces additional statutory SIP planning requirements for areas
classified as “Serious.”77 These additional requirements must be reflected in the states’ initial SIP
submissions.
Subpart 4 requires states to achieve attainment for Moderate areas as expeditiously as practicable,
but no later than six years after designation; Serious areas must achieve attainment no later than
10 years from designation as nonattainment. Under the general provisions in Subpart 1, which has
no classifications, attainment must be achieved no later than five years from the effective
designation date. Both Subpart 478 and Subpart 179 included provisions for extensions.
National Regulations
EPA anticipates that in many cases, stationary and mobile source controls and additional
reductions currently being adopted to attain the 2006 PM2.5 standards in conjunction with
expected emission reductions from implementing national regulations and strategies will help
states meet the proposed standards. These national actions EPA referenced include the
• Cross-State Air Pollution Rule (CSAPR);80
• Mercury and Air Toxics Standards (MATS);81
• Light-Duty Vehicle Tier 2 Rule;82
• Heavy Duty Diesel Rule;83
• Clean Air Nonroad Diesel Rule;84
76 CAA §188(b).
77 EPA references the “General Preamble” of the CAA and “Addendum” as guidance for the specific Subpart 4
statutory requirements: “State Implementation Plans; General Preamble for the Implementation of Title I of the Clean
Air Act Amendments of 1990” (57 Federal Register 13498, April 16, 1992) (the “General Preamble”) and “State
Implementation Plans for Serious PM10 Nonattainment Areas, and Attainment Date Waivers for PM10 Nonattainment
Areas Generally; Addendum to the General Preamble for the Implementation of Title I of the Clean Air Act
Amendments of 1990” (59 Federal Register 41998, August 16, 1994) (the “Addendum”).
78 EPA may grant no more than two one-year extensions of the initial attainment date for Moderate designated areas
under Section 188(d) of the CAA, and no more than five years for areas designated as Serious under Section 188(e).
79 Under Section 172(a)(2)(A) of the CAA, EPA may grant an area an extension of the initial attainment date for one to
five years (in no case later than 10 years after the designation date for the area).
80 76 Federal Register 48208-48483, August 8, 2011. The CSAPR was intended to replace EPA’s 2005 Clean Air
Interstate Rule (CAIR, 70 Federal Register 25162, May 12, 2005), promulgated under the CAA, 42 U.S.C. 7401 et
seq.; see http://www.epa.gov/crossstaterule/index.html. The CAIR had been remanded by the D.C. Circuit and to EPA
in 2008 (North Carolina v. EPA 531 F.3d 896 (D.C. Cir. 2008)). For information regarding the CAIR rule 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, and EPA “Clean Air Interstate Rule” at
http://www.epa.gov/air/interstateairquality/#older.
81 77 Federal Register 9304-9513, February 16, 2012.
82 65 Federal Register 6822-6870, February 10, 2000.
83 65 Federal Register 59896-59978, October 6, 2000.
84 69 Federal Register 38958-39273, January 29, 2004.
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• Regional Haze Regulations and Guidelines for Best Available Retrofit
Technology Determinations;85
• NOx Emission Standard for New Commercial Aircraft Engines;86
• Emissions Standards for Locomotives and Marine Compression-Ignition
Engines;87
• Control of Emissions from Nonroad Spark Ignition Engines and Equipment;88
• Category 3 Oceangoing Vessels;89
• Reciprocating Internal Combustion Engines (RICE) National Emissions
Standards for Hazardous Air Pollutants (NESHAPS);90 and
• New Source Performance Standards and Emissions Guidelines for
Hospital/Medical/Infectious Waste Incinerators Final Rule Amendments.91
Stakeholders and some Members of Congress are skeptical about EPA’s expectations with respect
to the corollary benefits associated with some of these regulations, and raise concerns about
pending efforts to delay some of the more recent programs and historical delays of others. Of
particular concern are the Cross-State Air Pollution Rule (“Cross-State Rule,” or CSAPR),92
which 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 Appeals,93 and the Mercury and Air Toxics
Standards (MATS), which EPA itself has stayed with regard to new plants, pending
reconsideration. On October 5, 2012, the U.S. Department of Justice filed a petition94 seeking en
banc rehearing of the D.C. Circuit’s August 21, 2012, decision regarding the CSAPR. The D.C.
Circuit denied requests for both a panel and the en banc rehearing on January 24, 2013.95 To date,
EPA has not made a decision regarding its response to the Court’s denial for a rehearing. Other
rules remanded or reconsidered include the hazardous air pollutant (“MACT”) standards for
boilers and cement kilns. EPA has delayed implementation of the boiler MACT rules for more
85 70 Federal Register 39104-39172, July 6, 2005.
86 70 Federal Register 69644-69687, November 17, 2005.
87 73 Federal Register 37095-37144, republished June 30, 2008.
88 73 Federal Register 59034-59380, October 8, 2008.
89 75 Federal Register 22896-23065, April 30, 2010.
90 75 Federal Register 51570-51608, August 20, 2010; Proposed Amendments 77 Federal Register 33812-33857, June
7, 2012.
91 74 Federal Register 51415, October 6, 2009.
92 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. See also footnote 80.
93 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),” http://epa.gov/crossstaterule/
for this decision and other related documents.
94 U.S. EPA, http://epa.gov/crossstaterule/pdfs/Rehearing_Petition_617874.pdf. For status of the petition see EPA
website, “Cross-State Air Pollution Rule (CSAPR),” at http://epa.gov/crossstaterule/.
95 EME Homer City Generation, L.P. v. Environmental Protection Agency, D.C. Cir., No. 11-1302, January 24, 2013,
Orders. See U.S. EPA’s website, “Cross-State Air Pollution Rule (CSAPR),” http://epa.gov/crossstaterule/.
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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.
Potential Impacts of More Stringent PM Standards
The impacts of the revising PM NAAQS can be both potentially far-reaching and indirect. As
discussed earlier in this report, the NAAQS by itself does not compel any specific direct pollution
control measures. Rather it starts a process that could result in significant required investments by
emitting sources in control measures. In addition to these costs, the eventual result is projected by
EPA to be potentially significant health benefits. Estimates of health and welfare risk reductions
and costs associated with control strategies for areas potentially not in compliance provide some
insights into potential impacts of the June 2012 proposed and January 2013 final revisions to the
PM NAAQS.
The Clean Air Act requires that NAAQS be set solely on the basis of public health and welfare
protection, while costs and feasibility are generally taken into account in implementation of the
NAAQS (a process that is primarily a state responsibility). As discussed previously, in setting and
revising the NAAQS, the CAA directs the EPA Administrator to protect public health with an
adequate margin of safety. This language has been interpreted, both by the agency and by the
courts, as requiring standards be based on a review of the health impacts, without consideration of
the costs, technological feasibility, or other nonhealth criteria.96
Nevertheless, coinciding with the PM NAAQS final rule released on December 14, 2012, and
proposed rule in the June 29, 2012, Federal Register, EPA released regulatory impact analyses
(RIA)97 assessing the costs and benefits of setting the standard at the proposed and other
alternative levels, to meet its obligations under Executive Order 12866 and in compliance with
guidance from the White House Office of Management and Budget.98 EPA emphasized that the
RIA is for informational purposes and that decisions regarding revisions to the PM NAAQS are
not based on consideration of the analyses in the RIA in any way. In addition, the expected costs
are more difficult to predict than for many other regulations because the ultimate pollution control
requirements, which are the primary costs, will depend on a variety of factors, such as state
regulatory decisions and the results of monitoring and modeling analysis of designated areas that
are not fully knowable at this time.
In part in response to comments received and considered following the June 2012 proposal, EPA
revised its RIA for the final rule.99 Table 2 below presents a range of EPA’s estimated economic
costs, monetized benefits, and net benefits (subtracting total costs from the monetized benefits)
96 With regard to the nonrelevance of cost considerations, see generally Whitman v. American Trucking Associations,
531 U.S. 457, 465-472, 475-76 (2001).
97 U.S. EPA, “Regulatory Impact Analysis for the Final Revisions to the National Ambient Air Quality Standards for
Particulate Matter,” http://www.epa.gov/pm/2012/finalria.pdf, and U.S. EPA, “Regulatory Impact Analysis for the
Proposed Revisions to the National Ambient Air Quality Standards for Particulate Matter,” EPA-452/R-12-003 June
2012, available at http://www.epa.gov/ttn/ecas/ria.html.
98 58 Federal Register 51735, October 4, 1993. See the White House OMB website, Regulatory Matters, at
http://www.whitehouse.gov/omb/regulatory_affairs/default.
99 See footnote 54.
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associated with achieving the revised PM2.5 standards in the final rule published in January 2013,
and other alternatives considered as presented in EPA’s revised RIA.
Table 2. EPA’s Estimated Total Monetized Benefits, Costs, and Net Benefits of
Attaining Alternative PM2.5 NAAQS as in 2020 for the January 2013 Final Rule
(2010 $ in millions)
Final and Alternative
Annual Standard
Estimated Monetized
Estimated
Estimated Net
(µg/m3)
Benefitsa
Total Costsb Benefits
Discount Ratec
3%
7%
7%
3%
7%
13 $1,300
to
$11 to $100
$1,200 to
$1,100 to
$2,900
$2,900
$2,600
12 $4,000
to
$3,600 to
$53 to $350
$3,700 to
$3,300 to
$9,100
$8,200
$9,000
$8,100
11 $13,000
to
$12,000 to
$320 to
$11,000 to
$10,000 to
$29,000
$26,000
$1,700
$29,000
$26,000
Source: Adapted from Environmental Protection Agency’s “U.S. EPA, “Regulatory Impact Analysis for the Final
Revisions to the National Ambient Air Quality Standards for Particulate Matter,” December 2012, Table ES-2, p.
ES-15, http://www.epa.gov/pm/2012/finalria.pdf. Estimates and results are as reported by EPA and have been
rounded after calculation.
Note: Results are rounded to two significant digits after calculation for presentation and computation as
reported by EPA. Estimates (costs and benefits) reflect full attainment in 2020, which includes implementation of
several national programs and are incremental to compliance with the 2006 PM2.5 NAAQS. The discount rates
are as recommended in EPA’s Guidelines for Preparing Economic Analyses (2000) and OMB Circular A-4 (2003).
a. The reduction in premature deaths each year accounts for over 90% of total monetized benefits. Mortality
risk evaluation assumes discounting over the Science Advisory Board-recommended 20-year segmented lag
structure. Not al possible benefits or “disbenefits” are quantified and monetized in this analysis. Data
limitations prevented EPA from quantifying these endpoints, and as such, these benefits are inherently more
uncertain than those benefits that EPA was able to quantify.
b. The two cost estimates do not represent lower- and upper-bound estimates, but represent estimates
generated by two different methodologies. The lower estimate is generated using the fixed-cost
methodology, which assumes that technological change and innovation will result in the availability of
additional controls by 2020 that are similar in cost to the higher end of the cost range for current, known
controls. The higher estimate is generated using the hybrid methodology, which assumes that while
additional controls may become available by 2020, they become available at an increasing cost, and the
increasing cost varies by geographic area and by degree of difficulty associated with obtaining the needed
emissions reductions.
c. Due to data limitations, EPA was unable to discount compliance costs for al sectors at the 3% discount
rate. Consequently, the net benefit calculations at 3% were computed by subtracting the costs at the 7%
rate from the monetized benefits with the 3% rate.
As shown in Table 2, EPA estimated that the monetized benefits associated with the January 2013
final revised PM2.5 annual standard of 12 µg/m3 would range $4.0 billion to $9.1 billion per year
in 2020 (2010 $), compared to annual costs ranging from $53.0 million to $350.0 million. EPA
also noted that a full accounting of benefits would include additional environmental and societal
benefits that were not quantified in the analysis. The basis for the benefits calculations100 is health
100 See p. Section ES.2.2. beginning on p. ES-10, and discussion of health benefits in Chapter 5 beginning p. 5-1, and
(continued...)
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and welfare impacts attributable to reductions in ambient concentration of PM2.5 resulting from a
reasonable, but “speculative,” array of known state implementation emission control strategies
selected by EPA for purposes of analysis. The analysis does not model the specific actions that
each state will undertake or emerging technologies in implementing the alternative PM2.5
NAAQS. EPA notes that reductions in annual premature deaths represent a substantial proportion
of total monetized benefits (over 90%).101
EPA estimated total costs under partial and full attainment of several alternative PM standards.102
The engineering costs generally include the costs of purchasing, installing, and operating the
referenced control technologies. The technologies and control strategies selected for analysis are
illustrative of one way in which nonattainment areas could meet a revised standard. EPA
anticipates that in actual SIPS, state and local governments will consider programs that are best
suited for local conditions as there are various options for potential control programs that would
bring areas into attainment with alternative standards. EPA includes a detailed discussion of the
limitations and uncertainties associated with the benefits assumptions and analyses.103
While recognizing the need to adequately protect against potential health concerns associated
with PM, some Members and stakeholders are apprehensive that EPA has underestimated
potential costs and are concerned with the potential monetary consequences associated given the
current economic environment. In particular, some stakeholders question the validity of EPA’s
reliance on the associated impacts of other national regulations in reducing the potential burdens.
Critics are concerned that this results in underestimating the number of areas (counties) likely to
be affected in terms of their ability to attain the proposed alternative PM NAAQS and the
expected associated costs of necessary measures that will be required in the form of SIPs.
Reaction to the Revised PM NAAQS
Prior to EPA’s June 2012 proposed rule to revise the PM NAAQS, stakeholders were providing
evidence and arguments in letters, press releases, at public hearings and other forums for their
preferred recommendations, and EPA received numerous comments during various stages of
development of the criteria and policy documents. In general, business and industry opposed
more stringent standards particularly in light of the current national and global economic
environment; and public health and environmental advocacy groups advocated support for more
stringent standards based on the continuing evidence of health effects from ongoing scientific
research. As mentioned earlier, several states petitioned EPA, and subsequently filed suit in the
D.C. Circuit Court urging timely completion of EPA’s review of the PM NAAQS in response to
the February 2009 remand. Other state air quality regulators recognized the need to ensure
adequate health protection from PM, but expressed concerns about the impacts of more stringent
PM NAAQS on already strained state budgets.
Proponents of more stringent standards generally stress that
(...continued)
welfare benefits in Chapter 6 p. 6-1 of the EPA December 2012 RIA, footnote 97.
101 U.S. EPA, p. ES-15 December 2012 RIA; see footnote 97.
102 See discussion for engineering cost analysis in Chapter 7 beginning p. 7-1 (pdf p. 455) June 2012 RIA, footnote 97.
103 See the Executive Summary in the RIA accompanying the January 2013 final rule: ES.4 Caveats and Limitations,
beginning on p. ES-21.
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• the PM2.5 standards should be at least as stringent as the more stringent combined
daily and annual levels recommended in the 2006 EPA staff paper, and those
recommended by the CASAC;
• scientific evidence of adverse health effects is more compelling than when the
standards were revised in 2006;
• more stringent standards ensure continued progress toward protection of public
health with an adequate margin of safety as required by the CAA; and
• welfare effects, particularly visibility, should be enhanced.
Critics of more stringent PM NAAQS stress that
• more stringent (and in some cases the existing) standards are not justified by the
scientific evidence; the proposal does not take into account studies completed
since the 2009 cutoff;
• requiring the same level of stringency for all fine particles without distinguishing
sources is unfounded;
• costs and adverse impacts on regions and sectors of the economy are excessive;
• EPA has potentially overstated the expected benefits and underestimated
expected costs;
• revising the standards could impede implementation of the existing (2006) PM
NAAQS and the process of bringing areas into compliance, given the current
status of this process;
• the benefits (and costs) associated with implementation of the 2006 PM NAAQS,
as well as compliance with other relatively recent EPA air quality regulations that
are being implemented, have not yet been realized; and
• revisions to PM NAAQS are unnecessary as shown by EPA’s trends data that
annual and 24-hour measured PM national concentrations have declined 24% and
28% respectively from 2001 to 2010.
Congressional Activity
Not long after EPA’s release of its PM NAAQS proposal, the House Committee on Energy and
Commerce Subcommittee on Energy and Power held a hearing on June 28, 2012,104 on the
potential impacts of tightening the PM2.5 NAAQS. The focus of the debate was the regulatory
costs and burdens associated with the implementation of the revised standards, and potential
impacts on economic growth, employment and consumers. Just prior to EPA’s release of the June
2012 proposal, several Members urged the Administrator to include retaining the current (as of
2006) PM2.5 standard as an option for consideration in the agency’s proposal.105 In November
104 House Committee on Energy and Commerce Subcommittee on Energy and Power June 28, 2012 hearing entitled,
“The American Energy Initiative: A Focus on the New Proposal to Tighten National Standards for Fine Particulate
Matter,” http://energycommerce.house.gov/hearing/american-energy-initiative-focus-new-proposal-tighten-national-
standards-fine-particulate.
105 See joint letter from Representatives Fred Upton, Chairman, Committee on Energy and Commerce, Ed Whitfield,
(continued...)
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2012, some Members106 urged EPA to consider delaying the final rule, while conversely, others,
along with some state attorneys general,107 supported timely completion of the agency’s review.
As mentioned earlier in this report, also in November 2012, some Members recommended EPA
reconsider its calculations of costs and benefits supporting the proposed rule. Also, although the
January 15, 2013, final rule did not modify the standards for inhalable “coarse” particles larger
than 2.5 but smaller than 10 microns (PM10), nor were modifications proposed in June 2012,
some Members maintained a particular interest in EPA’s consideration of the PM10 standards.
During the second session of the 111th and during the first session of the 112th Congress, some
Members raised concerns in letters to the EPA Administrator and during oversight hearings108
about EPA’s staff draft reports and CASAC recommendations regarding changes to the PM
NAAQS leading up to the June 2012 proposal. Some Members expressed their concerns of
potential impacts that the options for changing PM NAAQS standards could have on industry and
on agricultural operations. In letters to the EPA Administrator, several Members also
communicated their particular concerns with the agency’s consideration of stricter
standards for coarse particulates (PM10), including apprehensions of how changes may affect the
agricultural community.109 Additionally, during the 112th Congress, the House-passed Farm Dust
Regulation Prevention Act of 2011 (H.R. 1633) would have prohibited EPA from proposing,
finalizing, implementing, or enforcing any regulation revising primary or secondary NAAQS
applicable to PM “... with an aerodynamic diameter greater than 2.5 micrometers ...” for one year.
Further, the House-passed bill would have amended the CAA to exempt “nuisance dust” from the
act and would have excluded nuisance dust from references in the act to particulate matter “...
except with respect to geographic areas where such dust is not regulated under state, tribal, or
local law.... ” Nuisance dust was defined in the bill as particulate matter that
(1) is generated primarily from natural sources, unpaved roads, agricultural activities, earth
moving, or other activities typically conducted in rural areas; (2) consists primarily of soil,
other natural or biological materials, windblown dust, or some combination thereof; (3) is
not emitted directly into the ambient air from combustion, such as exhaust from combustion
engines and emissions from stationary combustion processes; (4) is not comprised of
(...continued)
Chairman, Subcommittee on Energy and Power, and Joe Barton, Chairman Emeritus, June 6, 2012,
http://energycommerce.house.gov/letter/letter-epa-regarding-national-ambient-air-quality-standards.
106 See November 21, 2012, letter from 47 Members of the House of Representatives to the U.S. EPA Administrator,
http://latta.house.gov/uploadedfiles/2012_11_29_final_pm2_5_letter_signed_w_attchmt.pdf. Also see press release
available on Representative Bob Latta’s website at http://latta.house.gov/news/documentsingle.aspx?DocumentID=
314585.
107 See December 6, 2012, letter from nine State Attorneys General to the Acting Administrator of the Office of
Information and Regulatory Affairs, the White House Office of Management and Budget, http://www.eenews.net/
assets/2012/12/10/document_gw_02.pdf.
108 For example, U.S. Congress, Senate Committee on Agriculture, Nutrition, and Forestry, Oversight Hearing to
Examine the Impact of EPA Regulation on Agriculture, 111th Cong., 2nd sess., September 23, 2010; and U.S. Congress,
House Committee on Agriculture, Public Hearing to Review the Impact of EPA Regulation on Agriculture, 112th
Cong., 1st sess., March 10, 2011.
109 Examples of letters to EPA Administrator Lisa Jackson include, but are not limited to, a joint letter from 99 House
Members, March 29, 2011, http://fincher.house.gov/press-release/fincher-noem-call-epa-abandon-unreasonable-dust-
standards; a joint letter from 75 House Members, September 27, 2010, http://agriculture.house.gov/letter/letter-epa-
national-ambient-air-quality-standards-naaqs-particulate-matter-dust; a joint letter from 21 Senators, July 23, 2010,
http://grassley.senate.gov/about/upload/Agriculture-07-23-10-dust-letter-to-EPA-signed-version-doc.pdf; an August 5,
2010, joint letter from former Senators Kent Conrad and Byron Dorgan and former Representative Earl Pomeroy. See
also CRS Report R41622, Environmental Regulation and Agriculture, coordinated by Megan Stubbs.
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residuals from the combustion of coal; and (5) does not include radioactive particulate matter
produced from uranium mining or processing.
A general provision included in FY2012 House-reported EPA appropriations language (H.R.
2584, Title IV, and §454)110 would have restricted the use of FY2012 appropriations “to modify
the national primary ambient air quality standard or the national secondary ambient air quality
standard applicable to coarse particulate matter (generally referred to as “PM10”).”111 No
comparable provision was retained in the Consolidated Appropriations Act, 2012 (P.L. 112-74),
enacted December 23, 2011, which ultimately included EPA’s FY2012 appropriation.
NAAQS decisions have often been a source of significant concern to many in Congress. The
evolution and development of the PM (and ozone) NAAQS, in particular, have been the subject
of extensive oversight. For example, following promulgations of the 1997 NAAQS Congress held
28 days of hearings on the EPA rule. Congress enacted legislation specifying deadlines for
implementation of the 1997 standard, funding for monitoring and research of potential health
effects, and the coordination of the PM (and ozone) standard with other air quality regulations.
During the 109th Congress, hearings were held regarding implementation and review of the PM
NAAQS leading up to promulgations of the 2006 PM NAAQS.112
Because of the potential impacts PM NAAQS could have on both public health and the economy,
EPA’s final rule published on January 15, 2013, modifying these standards generated mixed
reactions from some Members, and the issue will likely be of continued interest in the 114th
Congress, as will EPA’s next five-year review of the PM NAAQS, which the agency commenced
at the beginning of December 2014.113
Conclusions
EPA’s changes to the PM NAAQS in its final rule published on January 15, 2013, following
completion of its statutorily required review, have continued to garner attention and conflicting
concerns among a diverse array of stakeholders, and in Congress. As evidenced by the history of
the PM NAAQS, the level of scrutiny and oversight could increase in the coming months.
Because both the health and economic consequences of particulate matter standards are
potentially significant, the PM NAAQS are likely to remain a prominent issue in the 113th
Congress.
110 The Department of the Interior, Environment, and Related Agencies Appropriations Act, 2012 (H.R. 2584, Title IV
Section 454) as reported by the House Committee on Appropriations on July 19, 2011. From July 25, 2011, to July 28,
2011, the House considered H.R. 2584 as reported July 19, 2011, but the House floor debate was suspended.
111 See CRS Report R42332, Environmental Protection Agency (EPA) FY2012 Appropriations, by Robert Esworthy,
and CRS Report R41979, Environmental Protection Agency (EPA) FY2012 Appropriations: Overview of Provisions in
H.R. 2584 as Reported, by Robert Esworthy.
112 For example, see U.S. Senate Committee on Environment and Public Works, Subcommittee on Clean Air, Climate
Change, and Nuclear Safety, Implementation of the Existing Particulate Matter and Ozone Air Quality Standards,
November 10, 2005.
113 U.S. Environmental Protection Agency, “Notice of Workshop and Call for Information on Integrated Science
Assessment for Particulate Matter,” 79 Federal Register 71764, December 3, 2014, http://www.gpo.gov/fdsys/pkg/FR-
2014-12-03/pdf/2014-28278.pdf.
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EPA asserts that its review and analyses of scientific evidence showed that revising the PM
NAAQS could potentially result in fewer adverse health effects for the general population and
particularly sensitive populations such as children, asthmatics, and the elderly, as well as
improved welfare effects. Nonetheless, concerns remain with regard to the potential associated
costs. In its assessment of the impacts of revising the PM NAAQS, EPA expected that relatively
few additional areas (counties) would be in nonattainment and require more stringent pollution
controls to achieve compliance. Industry, some Members, and some state representatives
remained concerned that the January 2013 revised PM NAAQS would result in more areas than
anticipated by EPA being classified as nonattainment and needing to implement new controls on
particulate matter. Further, they are concerned that stricter standards may mean more costs for the
transportation and industrial sectors, including utilities, refineries, and the trucking industry,
affected by particulate matter controls. Others stress that related ongoing control efforts from
prior and recently promulgated actions are expected to reduce the potential number of
nonattainment areas, or at least facilitate compliance.
EPA’s review and establishment of the 1997 PM NAAQS was the subject of litigation and
challenges, including a Supreme Court decision in 2001.114 EPA’s 1997 promulgation of standards
for both coarse and fine particulate matter prompted critics to charge EPA with over-regulation
and spurred environmental groups to claim that EPA had not gone far enough. Not only was the
science behind the PM NAAQS challenged, but EPA was also accused of unconstitutional
behavior. More than 100 plaintiffs sued to overturn the standard. Although EPA’s decision to issue
the standards was upheld unanimously by the Supreme Court, for the most part, stakeholders on
both sides of the issue continued to advocate their recommendations for more stringent and less
stringent PM standard. Several states and industry, agriculture, business, and environmental and
public health advocacy groups petitioned the U.S. Court of Appeals for the District of Columbia
Circuit, challenging certain aspects of EPA’s revisions of the PM NAAQS as promulgated
December 2006. A February 24, 2009, decision by the D.C. Circuit granted the petitions in part,
denying other challenges, and remanded the standards to EPA for further consideration. The court
did not specifically vacate the 2006 PM NAAQS and implementation is currently underway.
EPA received considerable (more than 230,000 written) comments in response to the June 2012
proposal. Concerned stakeholders may return to the courts or initiate challenges in response to the
final standards published on January 15, 2013, thus potentially furthering delays in designating
nonattainment areas, and states’ development and implementation of SIPs.
114 Whitman v. American Trucking Associations, 531 U.S. 457 (2001). Along with deciding issues specific to PM and
ozone, the Court ruled unanimously that costs could not be considered in setting primary (health based) NAAQS.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Appendix A. Chronological Summary
of Key Milestones Subsequent to the
January 2013 PM NAAQS Final Rule
As part of the D.C. Circuit’s decision and a related Consent Agreement, EPA agreed to issue final
revised PM NAAQS by December 14, 2012. The timeline presented in Table A-1 below reflects
the most recent projected milestone dates subsequent to the January 15, 2013, publication of the
final rule revising the PM NAAQS. These milestones are driven primarily by statutory
requirements under the CAA, and are based on milestones identified in the June 29, 2012,
Federal Register and EPA fact sheets accompanying the agency’s proposed and final regulatory
actions. The CAA does not specify a timeframe with regard to when states must meet secondary
PM standards; relevant milestones are determined by EPA and states through the implementation
planning process.
Table A-1. Milestone Chronology for Actions Subsequent to the January 2013 Final
Revisions to the PM NAAQS
Actual and Projected Date
January 2013 Revised PM NAAQS Milestones
December 14, 2012, Final Rule Released
The EPA Administrator signed the final rule on December 14, 2012, as per
(F.R. published on January 15, 2013)
the D.C. Circuit June 2012 and as agreed to under a Consent Decree. The
final rule was published in the F.R. on January 15, 2013.
December 2013 Proposal of Area
State-tribal area designation recommendations (based on 2010-2012
Designations (required by CAA within one
monitoring data).
year after promulgation of PM NAAQS final
rule)–Completed
August 2014 EPA Response–Completed
EPA notifies states and tribes regarding modifications to their
recommendations.
December 2014 Final Area Designations
EPA promulgates final area designations; expected effective data early
(required one year after states and tribes
2015.
make recommendations)–Completed
No Date Available (pending)
EPA proposes PM2.5 implementation rule.
Early 2016 (one year after the final
States with new transportation projects submit conformity determination
designation effective date of early 2015)
within one year of the effective date of nonattainment designation.
Not Available
EPA promulgates final PM2.5 implementation rule.
Early 2018 (3 years after final area
States and tribes are to submit revised implementation plans (SIPs) to
designations effective date of January 15,
achieve PM2.5 compliance in nonattainment areas required three years after
2013)
final designations.
Early 2020-2025 (5-10 years after final area
CAA NAAQS statutory compliance deadline that States must meet the
designations effective date of January 15,
health standards “as expeditiously as practicable” but not later than five
2013)
years after designations. A state may request a possible extension to 2025,
depending on the severity of an area’s fine particle pollution problems and
the availability of pollution controls.
Source: Prepared by CRS based on U.S. Environmental Protection Agency fact sheets, technical documents,
guidance accompanying the EPA PM NAAQS final rule published on January 15, 2013, 77 Federal Register 38889-
39055, and the proposed rule, 77 Federal Register 38889-39055, June 29, 2012. See http://www.epa.gov/pm/
actions.html.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Appendix B. Supporting EPA Scientific and
Policy Documents, and CASAC Review
Table B-1. Chronological Listing of EPA Workshops, and Technical and Policy
Documents in Support of the 2013 Revised PM NAAQS
Workshop/Draft or Final Document
Date
Integrated Science Assessment for Particulate Matter: Cal for Information
June 2007
Workshop to Discuss Policy-Relevant Science to Inform EPA’s Integrated Plan for the Review of
July 2007
the Primary PM NAAQS - Final Agenda
Workshop to Discuss Policy-Relevant Science to Inform EPA’s Integrated Plan for the Review of
July 2007
the Secondary PM NAAQS - Final Agenda
PM NAAQS Integrated Review Plan - Draft
October 2007
PM NAAQS Integrated Review Plan - Final
March 2008
Notice of Workshop to Review Initial Draft Materials for the PM Integrated Science Assessment
May 2008
Integrated Science Assessment for Particulate Matter - First External Review Draft
December 2008
PM NAAQS: Scope and Methods Plan for Urban Visibility Impact Assessment
February 2009
PM NAAQS: Scope and Methods Plan for Health Risk and Exposure Assessment
February 2009
Integrated Science Assessment for Particulate Matter - Second External Review Draft
July 2009
Particulate Matter Urban-Focused Visibility Assessment—External Review Draft
September 2009
Risk Assessment to Support the Review of the PM Primary National Ambient Air Quality
September 2009
Standards - External Review Draft
Review of Urban Visibility Public Preference Studies (Final Report)
September 2009
Urban-Focused Visibility Assessment Data File
November 2009
Corrections to Relative Humidity Values Used in the Draft UFVA, Corrected Graphics, Tables,
November 2009
and Availability of Detailed Data File for Current Conditions
Integrated Science Assessment for PM (Final Report)
December 2009
Particulate Matter Urban-Focused Visibility Assessment - Second External Review Draft
January 2010
Statistical Analysis of Existing Urban Visibility Preference Studies
February 2010
Corrections to Relative Humidity Values Used in the Draft Urban-Focused Visibility Assessment, February 2010
Availability of Data File Comparing Incorrect RH Data to Corrected RH Data for Atlanta and
Birmingham
Quantitative Health Risk Assessment for Particulate Matter—Second External Review Draft
February 2010
Revision to Section 3.3.5 of the Second External Review Draft of the PM Urban Visibility
March 2010
Assessment
Analyses of PM2.5 Data for the PM NAAQS Review, Hassett-Sipple
March 2010
Quantitative Health Risk Assessment for Particulate Matter - Final Report
June 2010
Quantitative Health Risk Assessment for Particular Matter - Air Quality Data Files (for hybrid
June 2010
rollback-based analyses)
Quantitative Health Risk Assessment for Particular Matter - Air Quality Data Files (for
June 2010
proportional and locally focused rol back-based analyses)
Corrected Urban-Focused Visibility Assessment Data File
July 2010
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Workshop/Draft or Final Document
Date
Particulate Matter Urban-Focused Visibility Assessment - Final Document
July 2010
PM10 and PM10-2.5 Air Quality Analyses, Schmidt and Jenkins
July 2010
Particulate Matter Air Quality Data Requested from Epidemiologic Study Authors
July 2010
SANDWICH-Related Correction to the UFVA Data File, as Used for the Final Document
July 2010
Explanation of Error in Table 4-3 of the Final UFVA
July 2010
PM2.5 Air Quality Analyses
July 2010
Assessment of the Use of Speciated PM2.5 Mass-Calculated Light Extinction as a Secondary PM
November 2010
NAAQS Indicator of Visibility
Simplified Approaches for Calculation of Hourly PM2.5 Light Extinction Values From Hourly
November 2010
PM2.5 Mass and Relative Humidity Data and 24-hour PM2.5 Composition Data
Supplemental analysis of PM10 Air Quality from Locations Evaluated by Zanobetti and Schwartz
February 2011
(2009)
PM2.5 Air Quality Analyses - Update
April 2011
PM10 and PM10-2.5 Air Quality Analyses
April 2011
PM2.5 Distributional Statistical Analyses
April 2011
Assessment of PM2.5 FEMs Compared to Col ocated FRMs
April 2011
Investigation of 1-hour PM2.5 Mass Concentration Data from EPA-Approved Continuous
April 2011
Federal Equivalent Method Analyzers
Documentation of Measurement Uncertainty Estimates of Col ocated Chemical Speciation
June 2012
Network and IMPROVE Data for Use in the Secondary PM2.5 Standard for Visibility
Recommendations for Sampling Artifact Correction for PM2.5 Organic Carbon
June 2012
Technical Analyses to Support Surrogacy Policy for Proposed Secondary PM2.5 NAAQS under
June 2012
NSR/PSD Programs
Source: Prepared by CRS based on U.S. Environmental Protection Agency fact sheets, list of technical
documents available on its website Technology Transfer Network (TNN) National Ambient Air Quality
Standards (NAAQS): Particulate Matter (PM) Standards—Documents from Current Review at
http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html, and 77 Federal Register 38889-39055, June 29,
2012.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Table B-2. Chronological Listing of CASAC Reviews and Consultations
Review/Consultation
Date
CASAC Particulate Matter Review Panel’s Consultation on EPA’s Draft Integrated Review Plan for
November 2007
the National Ambient Air Quality Standards for Particulate Matter - Teleconference
CASAC Particulate Matter Review Panel’s Consultation on EPA’s Draft Integrated Review Plan for
January 2008
the National Ambient Air Quality Standards for Particulate Matter - Report
Consultation on Ambient Air Monitoring Issues Related to the Coarse Particle Speciation by the
March 2009
Clean Air Scientific Advisory Committee (CASAC) Ambient Air Monitoring & Methods
Subcommittee (AAMMS)
Review of EPA’s Integrated Science Assessment for Particulate Matter (First External Review Draft
May 2009
December 2008)
Consultation on EPA’s Particulate Matter National Ambient Air Quality Standards: Scope and
May 2009
Methods Plan for Health Risk and Exposure Assessment
Consultation on EPA’s Particulate Matter National Ambient Air Quality Standards: Scope and
May 2009
Methods Plan for Urban Visibility Impact Assessment
Review of Integrated Science Assessment for Particulate Matter (Second External Review Draft,
November 2009
July 2009)
Review of Particulate Matter Urban-Focused Visibility Assessment (External Review Draft,
November 2009
September 2009)
Review of Risk Assessment to Support the Review of the Particulate Matter (PM) Primary National November 2009
Ambient Air Quality Standards—External Review Draft (September 2009)
CASAC Review of Particulate Matter Urban-Focused Visibility Assessment—Second External
April 2010
Review Draft (January 2010)
CASAC Review of Quantitative Health Risk Assessment for Particulate Matter—Second External
April 2010
Review Draft (February 2010)
Review of the White Paper on Particulate Matter (PM) Light Extinction Measurements
April 2010
CASAC Review of Policy Assessment for the Review of the PM NAAQS—First External Review
May 2010
Draft (March 2010)
CASAC Review of Policy Assessment for the Review of the PM NAAQS—Second External Review September 2010
Draft (June 2010)
Source: Prepared by CRS based on U.S. Environmental Protection Agency fact sheets, list of CASAC
documents available on EPA’s websites “EPA Clean Air Scientific Advisory Committee (CASAC) Final Reports by
Topic” at http://yosemite.epa.gov/sab/sabproduct.nsf/WebReportsbyTopicCASAC!OpenView, and 77 Federal
Register 38889-39055, June 29, 2012.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Appendix C. Comparison of Potential
Nonattainment Areas for the January 2013 Final
Revised PM2.5 Annual Standard with the Final
Designations for the 2006 and 1997 PM2.5 NAAQS
Based on anticipated reductions associated with several other existing national air pollution
control regulations and programs (see discussion in “National Regulations” section), EPA had
predicted that seven counties in California would be the only areas unable to meet the new PM2.5
primary standard by 2020.115 Additionally, for illustrative purposes, EPA identified 66 counties
with monitors that showed concentrations of PM2.5 that would exceed the revised limit of the
primary annual standard of 12 µg/m3 based on 2009-2011 air quality monitoring data.116
According to EPA, 47 of these counties were determined nonattainment areas previously for
PM2.5 NAAQS based on earlier monitoring data available at the time and other factors considered.
The map in Figure C-1 Figure 1below depicts the potential nonattainment areas (counties) as
identified by EPA for the revised PM2.5 annual standards based solely on the 2009-2011 air
quality monitoring. The areas are depicted in the map for illustration purposes as a rough
approximation of the potential areas that may be designated nonattainment, as they do not take
into account other factors generally considered in making final designation determinations. The
specific counties based on the 2009-2011 monitoring data are shown in Table C-1, which also
shows the overlap of those nonattainment areas for the existing (2006) PM2.5 annual and/or daily
(24-hour) standards, and indicates those areas not previously designated nonattainment.117 EPA
predicted that data from future monitoring, 2011-2013, will possibly show continued decline in
levels of PM and their precursors, resulting in fewer nonattainment areas than shown by the 66
counties approximated.
115 See list of counties (http://www.epa.gov/pm/2012/2020table.pdfand) and map (http://www.epa.gov/pm/2012/
2020map.pdf) depicting EPA’s predictions for 2020, available on EPA’s website Particulate Matter (PM): Regulatory
Actions, http://www.epa.gov/pm/actions.html.
116 At the time of the June 2012 proposal, EPA had identified counties with monitors that showed concentrations of
PM2.5 that would exceed the proposed revised range of the primary annual standard of 12 µg/m3 to 13 µg/m3 based on
2008-2010 monitoring data.
117 For additional information, see CRS Report R40096, 2006 National Ambient Air Quality Standards (NAAQS) for
Fine Particulate Matter (PM2.5): Designating Nonattainment Areas, by Robert Esworthy.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
Figure C-1. Counties Not Meeting the January 2013 Revised Primary Annual PM2.5
NAAQS Based on 2009-2011 Air Monitoring Data as Predicted by EPA
(revised annual standard of 12 µg/m3)
Source: Created by CRS using data from the U.S. Environmental Protection Agency (EPA)—
http://www.epa.gov/airquality/particlepol ution/2012/20092011table.pdf. Base Map: Esri and U.S. Census.
Projection: Lambert Conformal Conic. US_Counties_FineParticle_juzel.mxd. February 4, 2013. EPA maps and
supporting documents regarding the January 2013 PM2.5 NAAQS revisions are available on EPA’s website
Particulate Matter (PM): Regulatory Actions, http://www.epa.gov/pm/actions.html.
Notes: Forty-seven of the projected counties shown on the map were in nonattainment areas for PM2.5 NAAQS
based on a comparison with areas designated nonattainment previously by EPA for the PM2.5 24-hour standard
(35 µg/m3) as promulgated in 2006 and/or the annual standard (15 µg/m3) that was retained in 2006 at the 1997
level. Specific counties and their comparisons are shown in Table C-1. The designations are presented for
illustrative purposes only. EPA will not designate areas as nonattainment for the revised PM2.5 NAAQS based on
2009-2011 air monitoring data. Designations will most likely be based on 2011-2013 air monitoring data that the
agency anticipates will indicate comparatively improved air quality.
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Table C-1. Nonattainment Areas for the January 2013 24-Hour PM2.5 NAAQS as
Estimated Using 2009-2011 Data, Final Designations 2006 24-Hour PM2.5 NAAQS
October 8, 2009, and Final Designations for the 1997 PM2.5 NAAQS Annual
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
ALABAMA
Birmingham, ALa
Jefferson Jefferson Jefferson
Shelby Shelby
Walker (p)
Walker (p)
Chattanooga, AL-TN-GA
Jackson (p)
UNDEFINEDb
Russell
ALASKA
Fairbanks, AK
Fairbanks N. Star (p)
Fairbanks N. Star
ARIZONA
Nogales, AZ
Pinal, CA
Pinal (p) (designated
February 3, 2011)c
ARKANSAS
UNDEFINEDb
Pulaski
CALIFORNIA
Chico, CA
Butte
(p)
Imperial County, CA
Imperial
(p)
Imperial
Los Angeles, CA
Los Angeles (p)
Los Angeles (p)
Los Angeles
Orange
Orange
Riverside (p)
Riverside (p)
Riverside
San Bernardino (p)
San Bernardino (p)
San Bernardino
Sacramento, CA
El Dorado (p)
Placer
(p)
Sacramento
Solano
(p)
Yolo
(p)
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
San Francisco Bay Area, CA
Alameda
Contra
Costa
Marin
Napa
San
Francisco
San
Mateo
Santa
Clara
Solano
(p)
Sonoma
(p)
San Joaquin Valley, CA
Fresno Fresno Fresno
Kern (p)
Kern (p)
Kern
Kings
Kings
Kings
Madera
Madera
Merced
Merced
Merced
San Joaquin
San Joaquin
Stanislaus
Stanislaus
Stanislaus
Tulare
Tulare
Tulare
Yuba City-Marysville, CA
Sutter
Yuba
(p)
CONNECTICUT
New York, NY-NJ-CT
Fairfield Fairfield
New Haven
New Haven
DELAWARE
Philadelphia- Wilmington,
New Castle
New Castle
PA-NJ-DE
DISTRICT OF COLUMBIA
Washington, DC-MD-VA
Entire District
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
GEORGIA
Atlanta, GA
Barrow
Bartow
Carrol
Cherokee
Clayton
Clayton
Cobb
Coweta
De
Kalb
Douglas
Fayette
Forsyth
Fulton
Fulton
Gwinnett
Hall
Heard
(p)
Henry
Newton
Paulding
Putnam
(p)
Rockdale
Spalding
Walton
Chattanooga, AL-TN-GA
Catoosa
Walker
Macon, GA
Bibb
Bibb
Monroe
(p)
Rome, GA
Floyd
Floyd
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
UNDEFINEDb
Dougherty
Muscogee
Richmond
Wikinson
HAWAII
UNDEFINEDb
Hawaii
IDAHO
Logan, UT-ID
Franklin
(p)
Pinehurst, ID
ILLINOIS
Chicago-Gary-Lake County,
Cook
Cook
IL-IN
DuPage
Grundy
(p)
Kane
Kendall
(p)
Lake
McHenry
Will
St. Louis, MO-IL
Madison
Madison
Monroe
Randolph
(p)
St. Clair
St. Clair
INDIANA
Chicago-Gary-Lake County,
Lake
IL-IN
Porter
Cincinnati-Hamilton, OH-KY-IN
Dearborn (p)
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
Evansville, IN
Dubois
Dubois
Gibson
(p)
Pike
(p)
Spencer
(p)
Vanderburgh
Warrick
Indianapolis, IN
Hamilton
Hendricks
Johnson
Marion
Marion
Morgan
Lafayette-Frankfort, IN
Louisville, KY-IN
Clark
Clark
Floyd
Floyd
Jefferson
(p)
Vincennes, IN
UNDEFINEDb
Lake
Spencer
Vanderbugh
Vigo
IOWA
Davenport-Moline-Rock Island,
Scott
IA-IL
Muscatine, IA
Muscatine
KENTUCKY
Cincinnati-Hamilton, OH-KY-IN
Boone
Campbel
Kenton
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
Huntington-Ashland,
Boyd
WV-KY-OH
Lawrence
(p)
Louisville, KY-IN
Bullitt
Bullitt
Jefferson
Jefferson
Paducah-Mayfield, KY-IL
UNDEFINEDb
Daviess
MARYLAND
Baltimore, MD
Anne Arundel
Baltimore
City
Baltimore
Carrol
Harford
Howard
Washington, DC-MD-VA
Charles
Frederick
Montgomery
Prince
George’s
Martinsburg, WV- Hagerstown,
Washington
MD
MICHIGAN
Detroit-Ann Arbor, MI
Livingston Livingston
Macomb
Macomb
Monroe
Monroe
Oakland
Oakland
St. Clair
St. Clair
Washtenaw
Washtenaw
Wayne
Wayne
Grand Rapids, MI
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
MISSISSIPPI
MISSOURI
St. Louis, MO-IL
Franklin
Jefferson
St.
Charles
St.
Louis
St. Louis City
St. Louis City
MONTANA
Libby, MT
Lincoln (p)
NEW JERSEY
New York, NY-NJ-CT
Bergen
Essex
Hudson
Mercer
Middlesex
Monmouth
Morris
Passaic
Passaic
Somerset Somerset
Union
Union
Philadelphia- Wilmington,
Burlington Burlington
PA-NJ-DE
Camden
Camden
Gloucester
Gloucester
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
NEW YORK
New York, NY-NJ-CT
Bronx Bronx
Kings
Kings
Nassau
Nassau
New York
New York
Orange
Orange
Queens
Queens
Richmond
Richmond
Rockland
Rockland
Suffolk
Suffolk
Westchester
Westchester
NORTH CAROLINA
Hickory, NC
Catawba
Greensboro-Winston Salem-
Davidson
High Point, NC
Guilford
UNDEFINED
OHIO
Canton-Massillon, OH
Stark Stark
Cincinnati-Hamilton, OH-KY-IN
Butler
Butler
Clermont
Hamilton
Hamilton
Warren
Cleveland-Akron- Lorain, OH
Ashtabula (p)
Cuyahoga
Cuyahoga
Cuyahoga
Lake
Lake
Lorain
Lorain
Medina
Medina
Portage
Portage
Summit
Summit
Summit
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
Columbus, OH
Coshocton (p)
Delaware
Fairfield
Franklin
Franklin
Licking
Dayton-Springfield, OH
Clark
Clark
Greene
Montgomery
Montgomery
Huntington-Ashland,
Adams (p)
WV-KY-OH
Gallia
(p)
Lawrence
Scioto
Parkersburg- Marietta, WV-OH
Washington
Steubenville- Weirton, OH-WV
Jefferson Jefferson Jefferson
Wheeling, WV-OH
Belmont
Youngstown, OH
OREGON
Klamath Falls, OR
Klamath
(p)
Oakridge, OR
Lane
(p)
PENNSYLVANIA
Allentown, PA
Lehigh
Northampton
Northampton
Harrisburg-Lebanon-Carlisle, PA
Cumberland
Dauphin
Lebanon
Dauphin
York
Johnstown, PA
Cambria Cambria Cambria
Indiana (p)
Indiana (p)
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
Lancaster, PA
Lancaster Lancaster
Liberty-Clairton, PA
Allegheny (p)
Allegheny (p)
Allegheny
Philadelphia-Wilmington,
Bucks Bucks
PA-NJ-DE
Chester
Chester
Chester
Delaware
Delaware
Delaware
Montgomery
Montgomery
Philadelphia
Philadelphia
Pittsburgh-Beaver Valley, PA
Allegheny (p)
Allegheny (p)
Allegheny
Armstrong
(p)
Armstrong (p)
Beaver
Beaver
Beaver
Butler
Butler
Greene (p)
Greene (p)
Lawrence (p)
Lawrence (p)
Washington
Washington
Washington
Westmoreland
Westmoreland
Westmoreland
Reading, PA
Berks
York, PA
York
TENNESSEE
Chattanooga, AL-TN-GA
Hamilton
Clarksville, TN-KY
Knoxville-Sevierville- La Follette,
Anderson Anderson
TN
Blount
Blount
Knox
Knox
Knox
Loudon
Loudon
Roane (p)
Roane (p)
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
TEXAS
UNDEFINEDb
Harris
UTAH
Logan, UT-ID
Cache
(p)
Provo, UT
Utah
(p)
Salt Lake City, UT
Box Elder (p)
Davis
Salt
Lake
Tooele
(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)
WEST VIRGINIA
Charleston, WV
Kanawha Kanawha Kanawha
Putnam
Putnam
Huntington-Ashland,
Cabell
Cabell
WV-KY-OH
Mason
(p)
Wayne
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
1997 PM2.5
2006 PM2.5
NAAQS
NAAQS
2013 PM2.5 NAAQS
Proxy
Designations
EPA Final
EPA Final
(based on 2009-
Designations
Designations
2011 Data)
Annual
24-Hour
Annual
Standard
Standard
Standard
(15 µg/m3)
(35 µg/m3 98th)
(12 µg/m3)
Designation Areas
Counties and Partial Counties (p)
Martinsburg, WV-Hagerstown,
Berkeley
MD
Morgantown, WV
Parkersburg- Marietta, WV-OH
Pleasants (p)
Wood
Wood
Steubenville- Weirton, OH-WV
Brooke Brooke Brooke
Hancock
Hancock
Hancock
Wheeling, WV-OH
Marshall
Marshall
Ohio
Ohio
UNDEFINEDb
Marion
WISCONSIN
Green Bay, WI
Madison-Baraboo, WI
Milwaukee-Racine, WI
Milwaukee
Racine
Waukesha
TOTALS
20 states and DC
18 states
16 states
38 areas
31 areas
NA
204 counties
120 counties
66 counties
173 whole counties
90 whole counties
NA
31 partial counties
30 partial counties
NA
Source: Compiled by CRS using data from EPA Fact Sheets accompanying the January 15, 2013, final PM
NAAQS rule, and EPA PM Designation’s 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.
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Air Quality: EPA’s 2013 Changes to the Particulate Matter (PM) Standard
b. The “designated areas” including one or more counties (or portions of counties) are as defined in the final
designations for the 2006 PM2.5. Those counties identified as potential nonattainment areas for the January
2013 revised standards that were not part of previously defined PM2.5 NAAQS designated areas are
characterized as “UNDEFINED” designation areas.
c. 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.
d. 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.
Author Contact Information
Robert Esworthy
Specialist in Environmental Policy
resworthy@crs.loc.gov, 7-7236
Congressional Research Service
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