Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

Congressional research reportNov 19, 2012

Ask Donna

What actually matters in this document.

Text

Air Quality: EPA’s 2012 Proposed Changes to

the Particulate Matter (PM) Standard

(name redacted)

Specialist in Environmental Policy

November 19, 2012

Congressional Research Service

7-....

www.crs.gov

R42671

CRS Report for Congress

Prepared for Members and Committees of Congress

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

Summary

On June 29, 2012, the Environmental Protection Agency (EPA) published a proposal to revise the

National Ambient Air Quality Standard (NAAQS) under the Clean Air Act (CAA) for particulate

matter (PM), in response to a June 6, 2012, order issued by the U.S. Court of Appeals for the

District of Columbia Circuit. Environmental and public health advocacy groups and 11 states had

petitioned the agency, and subsequently filed suit in the D.C. Circuit alleging that EPA failed to

perform its mandated duty to complete the review of the PM NAAQS within the statutory

deadline. EPA has agreed to issue final revised PM NAAQS by December 14, 2012. EPA’s review

of the PM NAAQS has generated considerable debate and oversight in Congress.

The June 2012 proposal would strengthen 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 range of 12 to 13 µg/m.3 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 would be

retained, as would the existing standards for larger, but still inhalable “coarse” particles less than

10 micrometers in diameter or PM10. “Secondary” standards that provide protection against

“welfare” (non-health) effects, such as ecological effects and material deterioration, would be

identical to the primary standards the same as in 2006, but the June 2012 proposal included two

options for a 24-hour PM2.5 standard to improve visibility.

In developing the June 2012 proposal, EPA reviewed scientific studies available since the

agency’s previous review in 2006. EPA determined, and the independent scientific advisory

committee mandated under the CAA (Clean Air Scientific Advisory Committee, or CASAC)

concurred, that evidence continues to show associations between particulates in ambient air and

numerous significant health problems, including aggravated asthma, chronic bronchitis, non-fatal

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 expects that the potential benefits of the proposed revisions would range from an estimated

low of $88.0 million to a high of $5.9 billion dependent on the concentration level and other

factors, and estimated costs would range from $2.9 million to $69.0 million. Some stakeholders

and some Members express concerns that the cost impacts will be more significant than EPA

estimated in those areas unable to comply with the new standards. EPA’s establishment of or

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.

Final revised PM NAAQS will start 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 the determination of “nonattainment” areas (primarily counties) based on multiple

years of monitoring data and other factors submitted by the states, state and local governments

must develop (or revise) State Implementation Plans (SIPs) outlining measures to attain the

standard. These often involve promulgation of new regulations by states, leading to the issuance

of revised air permits. The process typically takes several years. Based on statutory scheduling

requirements, designation of areas as nonattainment for any revised PM NAAQS would not be

determined until the end of 2014, and states would have until at least 2020 to achieve compliance.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

Contents

Introduction...................................................................................................................................... 1

Background ...................................................................................................................................... 3

EPA’s June 2012 Proposed Changes to the PM NAAQS................................................................. 5

Comparison of the June 2012 PM2.5 Annual Standard with Previous Promulgated and

Proposed Alternative PM Standards ....................................................................................... 7

Review Process Leading up to the June 2012 Proposed PM NAAQS ............................................ 7

Implementing the Proposed Revised PM2.5 NAAQS ..................................................................... 10

NAAQS Designation Process .................................................................................................. 11

June 2012 Proposed PM2.5 Annual NAAQS Potential Area Designations ........................ 12

State Implementation Plans (SIPs) .......................................................................................... 14

National Regulations ............................................................................................................... 15

Potential Impacts of More Stringent PM Standards....................................................................... 16

Reaction to the Proposed PM NAAQS .......................................................................................... 18

Congressional Activity................................................................................................................... 20

Conclusions.................................................................................................................................... 21

Figures

Figure 1. Counties Not Meeting the June 2012 Proposed Revised Primary Annual PM2.5

NAAQS Based on 2008-2010 Air Monitoring Data................................................................... 13

Tables

Table 1. Promulgated, Proposed, and Alternative PM2.5 Primary (Health) NAAQS ....................... 7

Table 2. EPA’s Estimated Total Monetized Benefits, Costs and Net Benefits of Attaining

Alternative PM2.5 NAAQS in 2020 ............................................................................................ 17

Table A-1. Milestone Chronology for Subsequent to the June 2012 Proposed PM NAAQS ........ 23

Table B-1. Chronological Listing of EPA Workshops, and Technical and Policy

Documents in Support of the June 2012 PM NAAQS Proposal ................................................ 24

Table B-2. Chronological Listing of CASAC Reviews and Consultations ................................... 26

Table C-1. Nonattainment Areas for the June 2012 24-Hour PM2.5 NAAQS as Estimated

Using 2008-2010 Data, Final Designations 2006 24-Hour PM2.5 NAAQS October 8,

2009, and Final Designations for the 1997 PM2.5 NAAQS Annual ............................................ 27

Appendixes

Appendix A. Chronological Summary of Key Milestones Subsequent to the

June 2012 PM NAAQS Proposal ............................................................................................... 23

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

Appendix B. Supporting EPA Scientific and Policy Documents, and CASAC Review ................ 24

Appendix C. Comparison of Potential Nonattainment Areas for the June 2012 Proposed

PM2.5 Annual Standard with the Final Designations for the 2006 and 1997 PM2.5

NAAQS ...................................................................................................................................... 27

Contacts

Author Contact Information........................................................................................................... 39

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

Introduction

The Environmental Protection Agency (EPA) Administrator signed a proposal to strengthen the

National Ambient Air Quality Standard (NAAQS)1 for particulate matter (PM) on June 14, 2012,2

intended to address potential health effects (including chronic respiratory disease and premature

mortality) associated with short- and long-term exposure to particulate matter. The date of the

proposal 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.3 EPA’s most

recent statutorily required review and proposal has generated controversy and national debate

among stakeholders, health and environmental advocacy groups, and states, as well as oversight

in Congress, as did the previous changes leading up to the existing PM NAAQS promulgated

October 2006, and those established in 1997.

The proposed rule subsequently published in the Federal Register June 29, 2012,4 started a nineweek public comment period 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.5 Per the

D.C. Circuit decision and as agreed to in a September 4, 2012, consent decree,6 EPA is to finalize

its decision regarding the PM NAAQS by December 14, 2012.

The June 2012 PM NAAQS proposal is the culmination of EPA’s statutorily required7 review of

the NAAQS under the Clean Air Act (CAA) based on studies available through mid-2009 and

recommendations of EPA staff and a scientific advisory panel (Clean Air Scientific Advisory

Committee, or CASAC8) established by the CAA.9 The agency initiated the review not long after

the 2006 promulgation of the PM NAAQS.10 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. Based on the scientific

evidence considered, EPA Administrator Lisa P. Jackson signed the proposal that would tighten

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).

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.

American Lung Ass’n v. EPA, D.D.C., No. 1:12-cv-243, order issued June 6, 2012.

U.S. EPA, National Ambient Air Quality Standards for Particulate Matter, Proposed Rule, 77 Federal Register

38889-39055, June 29, 2012.

U.S. EPA, Public Hearings for Proposed Rules–National Ambient Air Quality Standards for Particulate Matter, 77

Federal Register 39205, July 2, 2012.

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.

Section 109(d)(1)) of the CAA.

For information regarding the CASAC PM review panel and its activities and reports, see http://yosemite.epa.gov/sab/

sabpeople.nsf/WebCommittees/CASAC.

Section 109(d)(2) of the Clean Air Act.

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.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

the current standard primarily by lowering the annual health-based (“primary”) standard for fine

particles smaller than 2.5 microns (PM2.5). The proposal includes options for new secondary

standards to address visibility impacts in urban areas associated with PM2.5, but would not modify

the standards for inhalable coarse particles smaller than 10 microns or PM10.11 Because some

farming and livestock practices contribute to particulate matter emissions, the agricultural

community and some Members have maintained a particular interest in EPA’s consideration of

PM10 and the potential impacts on agricultural operations.12

As per statutory scheduling requirements under the CAA, the final designation of areas (primarily

counties) as nonattainment for any revised PM standards would not be determined until the end of

2014, and states would have until at least 2020 to achieve compliance. In its Regulatory Impact

Analysis (RIA) accompanying the proposed rule assessing the costs and benefits of proposed

revisions to the PM NAAQS, EPA estimated that strengthening the PM2.5 annual standard would

add further similar health benefits anticipated with the promulgation of the 2006 PM NAAQS.13

Others have suggested that potential health benefits of tightening the PM NAAQS might be

higher than EPA’s estimates.14 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 significantly allay impacts of complying with the proposed revised PM standards,

and anticipates that virtually all counties will meet the standards as proposed in 2020.

Several recent and pending EPA regulations implementing the various pollution control statutes

enacted by Congress have garnered vigorous oversight during the 112th Congress.15 Members

have 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 is being paid to the CAA, under which EPA has moved forward with

the first federal controls on emissions of greenhouse gases and also addressed emissions of

conventional pollutants from a number of industries. 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 June 2012 proposal is expected to generate further oversight.

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.

See CRS Report R41622, Environmental Regulation and Agriculture, coordinated by (name redacted).

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-20100955.

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.

See CRS Report R41561, EPA Regulations: Too Much, Too Little, or On Track?, by (name redacted) and (name re

dacted).

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

This CRS report summarizes EPA’s June 2012 proposed changes to the PM NAAQS and includes

comparisons with previous (1997) and current (2006) promulgated and proposed standards. Key

actions leading up to the June 2012 proposal, and potential issues and concerns associated with

the proposal to strengthen the PM2.5 annual standard, are also highlighted. For more information

regarding issues and implementation of the current 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 (name redacted), and CRS Report

R40096, 2006 National Ambient Air Quality Standards (NAAQS) for Fine Particulate Matter

(PM2.5): Designating Nonattainment Areas, by (name redacted).

Background

Particulate matter is one of six principal pollutants, commonly referred to as “criteria pollutants,”

for which EPA has promulgated NAAQS under the CAA.16 The others are ozone (O3, a key

measure of smog), nitrogen dioxide (NO2, or, inclusively, nitrogen oxides,17 NOx), 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 generally associated with dust from paved and unpaved roads,

certain industrial processes and agriculture, construction and demolition operations (including

mining), and biomass burning.

Establishing NAAQS does not directly limit emissions; rather, it represents the EPA

Administrator’s formal judgment regarding the level of ambient pollution that will protect public

health with an “adequate margin of safety.” Under Sections 108-109 of the CAA,18 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

welfare19 (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 the 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

42 U.S.C. 7408(a)(1).

The NAAQS is for NO2; nitrogen gases that are ozone precursors are referred to as NOx.

42 U.S.C. 7408(a)(1).

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)).

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

established NAAQS. EPA has revised the PM NAAQS three times, in 1987, 1997, and most

recently, October 2006, to ensure that the standards continue to provide adequate protection for

public health and welfare.20

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

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.21

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,22 and a coalition of 11 states filed a similar suit with

the U.S. District Court Southern District of New York.23 In response, the D.C. Circuit initially

directed EPA to complete its review of the PM NAAQS by June 7, 2012, and following a motion

filed by the agency, amended the deadline to June 14, 2012.24

Promulgation of revised PM NAAQS will initiate a series of statutorily required actions, starting

with EPA/States coordinated effort to designate areas (counties or portions of counties) with

respect to attainment or nonattainment of any new primary standards three years following the

effective date of published final revisions. Within three years of EPA’s final designations of areas,

states are required to submit plans (state implementations plans or SIPs) outlining how they will

achieve or maintain compliance with the revised primary PM NAAQS. The CAA is not specific

with respect to dates regarding when states must meet secondary PM standards. Relevant

milestones are determined by EPA and states through the implementation planning process.

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.

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 (name r

edacted).

American Lung Ass’n v. EPA, D.D.C., No. 1:12-cv-243, filed February 14, 2012.

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.

See footnote 3.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

EPA’s June 2012 Proposed Changes to the

PM NAAQS

EPA’s 1997 revisions to the PM NAAQS25 revised the standards focused on particles smaller than

10 microns (PM10 or coarse particles) established in 1987,26 and introduced standards for “fine”

particles smaller than 2.5 microns (PM2.5) for the first time. The current 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,27 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.

As proposed June 2012, the PM2.5 and PM10 standards and other implementation changes would

be as follows:28

Primary (Public Health) PM Standards

•

PM2.5: strengthen the annual standard, which currently is 15 micrograms per

cubic meter (µg/m3), by setting a new limit of 12 µg/m3 or 13 µg/m3; retain 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: retain 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).29

Secondary (Welfare) PM Standards

•

PM2.5 and PM10: secondary (welfare) NAAQS would be the same as the primary

standards, the same correlations as the 2006 PM NAAQS, with the exception of

visibility impairment associated with PM2.5.

62 Federal Register 38652-38896, July 18, 1997.

PM10 NAAQS were promulgated in 1987, 52 Federal Register 24640, July 1, 1987.

“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.

See footnote 2.

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.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

•

PM2.5 Visibility Impairment: add a distinct secondary standard defined in terms

of a PM2.5 visibility index based on speciated30 PM2.5 mass concentrations and

relative humidity data to calculate light extinction on a deciview (dv) scale31

similar the current Regional Haze Program.32 Specifically, set a 24-hour

averaging time of 30 or 28 deciviews (dv) based on a 90th percentile form over

three years. EPA is also seeking comment on alternative levels (down to 25 dv)

and averaging times (e.g., 4 hours).

Implementation Changes

•

Monitoring:33 update several aspects of monitoring regulations including

requiring relocating a small number of PM2.5 monitors to be collocated with

measurements of other criteria pollutants (e.g., nitrogen dioxide (NO2) and

carbon monoxide (CO)) near-roadway monitoring so to ensure these monitors are

at one location in each urban area with a population of 1 million or more, and

operational by January 1, 2015. 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 PM2.5. No changes to PM10 monitoring.

•

Air Quality Index (AQI): update the AQI (EPA’s color-coded tool for informing

the public how clean or polluted the air is 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 proposed revised annual

PM2.5 standard. EPA would also set 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”) would be set at 55 µg/m.3 The current

upper end for the “Hazardous” (500), “Unhealthy” (200) and “Very Unhealthy”

(300) AQIs would be retained.34

•

Prevention of Significant Deterioration (PSD):35 revise the PSD permitting

program (rules) with respect to the proposed 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 no later than the effective date of final revised PM NAAQS.

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.

“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:

Overview of EPA’s Proposal to Revise the Air Quality Standards for Particle Pollution (Particle Matter), p. 2,

http://www.epa.gov/air/particles/2012/fsoverview.pdf.

See U.S. EPA, “EPA’s Regional Haze Program,” http://www.epa.gov/visibility/program.html.

See 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.

See 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.

See footnote 33.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

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 June 2012 PM2.5 Annual Standard 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 June 2012 proposed changes to the PM2.5

annual standard in comparison to the annual and daily standards for 1997 and 2006 promulgated

standards, and alternative levels recommended prior to the 2006 final revisions.

Table 1. Promulgated, Proposed, and Alternative PM2.5 Primary (Health) NAAQS

PM2.5 NAAQS Options

24-hour Primary

Annual Primary

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

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

June 2012 Proposed Rule (June 2012)

35 µg/m3

13-12 µg/m3

Source: Prepared by the Congressional Research Service (CRS) with information from EPA’s 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).

Review Process Leading up to the June 2012

Proposed 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.36

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.”

For a detailed overview of the NAAQS process see CRS Report 97-722, Air Quality Standards:

The Decisionmaking Process.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

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 (CASAC37) 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. 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.38

Beginning June 2007 with its general call for information,39 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).40 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.

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.

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 non-health criteria. Costs and feasibility

are generally taken into account in NAAQS implementation (a process that is primarily a state responsibility).With

regard to the non-relevance of cost considerations, see generally Whitman v. American Trucking Associations, 531

U.S. 457, 465-472, 475-76 (2001).

U.S. EPA, “Integrated Science Assessment for Particulate Matter: Call for Information,” 72 Federal Register 35462,

June 28, 2007.

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.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

Table B-2 in Appendix B provides a chronological summary of CASAC consultations and

reviews of the supporting documents for the June 2012 proposal.

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 decisionmaking. The discontinuance of the closure letter was the subject of considerable debate,

particularly within the science community.41 EPA revised certain aspects (not including

reinstating the closure letter) of the CASAC review process most recently in May 2009.42

The April 2011 EPA staff paper concluded, and the CASAC panel concurred, 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, a range of alternatives were presented for consideration by the

Administrator for modifying the current PM NAAQS. These recommendations were the basis for

the Administrator’s decision, taking into account other factors including public comments

received, for proposing to strengthen the annual PM2.5 primary standard.43

The 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, the Administrator

provisionally concluded that the growing evidence continues 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.44

A perennial issue in conducting NAAQS reviews is whether the agency is basing its decisions on

those studies that reflect the latest science. In reviewing thousands of studies, the agency staff

ultimately need to establish a cut-off date, or be faced with the need for a continuous review. The

current review is based on studies completed by mid-2009, but in the June 29, 2012, Federal

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

See CRS Report RL33807, Air Quality Standards and Sound Science: What Role for CASAC? by (name red

acted).

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.

See 77 Federal Register 38900-38944, Section III. Rationale for Proposed Decisions on Primary PM2.5 Standards,

June 29, 2012.

See 77 Federal Register 38944-38963, Section IV. Rationale for Proposed Decisions on Primary PM10 Standards,

June 29, 2012.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

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.45

Implementing the Proposed 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.46 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.

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.47 Following 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 may

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 (TCMs), 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.48

Areas designated nonattainment for the NAAQS also are subject to new source review (NSR)

requirements. Enacted as part of the 1977 CAA Amendments and modified in the 1990 CAA

Amendments, NSR is designed to ensure that newly constructed facilities, or substantially

modified existing facilities, do not result in violation of applicable air quality standards. NSR

provisions outline permitting requirements both for construction of new major pollution sources

and for modifications to existing major pollution sources.49 The specific NSR requirements for

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.

For a general overview of the NAAQS designations process, see EPA’s “Designations” website at

http://www.epa.gov/air/urbanair/designations.html.

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.

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 MultiJurisdictional 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.

For an overview, including statutory authority and regulations, see EPA’s “New Source Review (NSR)” at

http://www.epa.gov/air/nsr/.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

affected sources depend on whether the sources are subject to “Prevention of Significant

Deterioration” (PSD) or nonattainment provisions.50 As discussed earlier (see “EPA’s June 2012

Proposed Changes to the PM NAAQS”), the June 2012 PM NAAQS proposal would revise the

PSD permitting program (rules) with respect to the proposed 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 requiring 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). 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 proposed revised PM NAAQS.

NAAQS Designation Process

The NAAQS designation process is intended as a cooperative federal-state-tribal51 process in

which states and tribes provide initial designation recommendations to EPA for consideration. In

Section 107(d)(1)(A) (42 U.S.C. 7407), the statute states that the governor of each state shall

submit a list to EPA of all areas in the state, “designating as ... nonattainment, any area that does

not meet (or that contributes to ambient air quality in a nearby area that does not meet) an air

quality standard” (emphasis added). Areas are identified as “attainment/unclassified”52 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.

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.53 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

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.

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.

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.

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).

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

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.54 The amended monitoring requirements were intended to

help federal, state, and local air quality agencies by adopting improvements in monitoring

technology. EPA is proposing additional modifications to the PM NAAQS monitoring network as

discussed earlier in this report.

In addition to air emission and air quality data, EPA considers a number of other relevant factors

in designating nonattainment area,55 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.

June 2012 Proposed PM2.5 Annual NAAQS Potential Area Designations

The June 2012 proposal to tighten the PM2.5 annual standard is expected to result in an increase in

the number of areas (typically defined by counties or portions of counties) designated

nonattainment. Similar to the strengthening of the PM2.5 daily (24-hour) standard in 2006, the

June 2012 proposed range of concentrations for the PM2.5 annual standard is expected to affect

primarily areas currently in nonattainment for the existing (2006) standards, but would also likely

include a few counties that have not been previously designated as nonattainment. EPA would not

require new nonattainment designations for PM10 primary NAAQS since the June 2012 proposal

would retain the existing (2006) standards.

Assuming EPA promulgates final PM NAAQS revisions by December 14, 2012, as indicated

earlier in this report, state and tribal area designation recommendations would be required under

the CAA to be submitted to EPA by December 2013 (within one year of the final rule). The CAA

requires EPA to make its final area designations within one year of the state and tribal

recommendations, projected to be December 2014. EPA is required to notify states and tribes of

its intended modifications to their recommendations 120 days (projected to be August 2014) prior

to promulgating final designations which are expected to become effective sometime in early

2015.

Revisions to Ambient Air Monitoring Regulations, final rule, 71 Federal Register 61235-61328, October 17, 2006.

http://www.epa.gov/air/particlepollution/actions.html.

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.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

The actual area designations of nonattainment are more than two years away and will be based on

more current monitoring data (likely 2011-2013) and other factors. However, EPA identified

counties with monitors that show 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. The map in Figure 1 below depicts these areas for the two proposed revised PM2.5 annual

standards. The areas are depicted in the map for illustration purposes as a rough approximation of

the potential areas that may be designated nonattainment for the June 2012 proposed standards.

The specific counties based on the 2008-2010 data are shown in Appendix C. The map below

shows the overlap of those nonattainment areas for the existing (2006) PM2.5 annual and/or daily

(24-hour), as well as additional areas not previously designated nonattainment. Although a direct

comparison of areas expected to be designated nonattainment for the June 2012 proposed PM2.5

standards with those areas designated nonattainment for the existing (2006) PM NAAQS56 is not

available, overlaying those counties with monitors based on 2008-2010 monitoring provides some

indication of potential areas.

Figure 1. Counties Not Meeting the June 2012 Proposed Revised Primary Annual

PM2.5 NAAQS Based on 2008-2010 Air Monitoring Data

(proposed revised annual standard of 12 µg/m3 and 13 µg/m3 )

Source: U.S. EPA, http://www.epa.gov/pm/2012/mapb.pdf. The above map, other maps and supporting

documents regarding the June 2012 PM NAAQS proposal are available on EPA’s website Particulate Matter (PM):

Regulatory Actions, http://www.epa.gov/pm/actions.html.

Notes: Specific counties are shown in Appendix C. The designations are presented for illustrative purposes

only. EPA will not designate areas as nonattainment any revised PM NAAQS based on 2008-2010 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.

For additional information, see CRS Report R40096, 2006 National Ambient Air Quality Standards (NAAQS) for

Fine Particulate Matter (PM2.5): Designating Nonattainment Areas, by (name redacted).

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

The 2006 revised PM NAAQS, which are currently being implemented, primarily affect 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, 2009.57 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.58 It is important to note that most of the

1997 PM2.5 nonattainment areas were only exceeding the annual standard; thus, tightening the 24hour 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.

Based on anticipated reductions associated with several other existing national air pollution

control regulations and programs (see discussion in “National Regulations” section), EPA

predicted that only a few counties would not be in compliance with the proposed primary

standards by 2020: two counties in California are projected to not meet the proposed annual

standard of 13 µg/m;3 an additional four counties in Alabama, Arizona, Michigan, and Montana

would not meet the proposed option of 12 µg/m3 for the annual standard.59

State Implementation Plans (SIPs)

Under the CAA, within three years of issuance of a NAAQS, all states are required to submit

“infrastructure” plans demonstrating that they have the basic air quality management components

necessary to implement the NAAQS.60 Areas designated attainment/unclassifiable will not have

to take steps to improve air quality, but under the statute they must take steps to prevent air

quality from deteriorating to unhealthy levels. For those areas ultimately designated

nonattainment, state, local, and tribal governments must outline detailed control requirements in

plans demonstrating how they will meet the revised primary annual PM2.5 NAAQS.

These plans, defined as state implementation plans and referred to as SIPs (TIPs for tribal

implementation plans), must be submitted to EPA three years after the effective date of the

agency’s final designations.61 EPA projects final area designations will be effective early 2015 for

the June 2012 proposed revisions, thus SIPs and TIPs would be required by early 2018. If states

fail to develop an adequate implementation plan, EPA can impose one. Under the CAA, states are

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 56.

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.

See EPA map and depicting projections for 2020 based on modeling of projected 2005 emissions,

http://www.epa.gov/air/particles/2012/mapa.pdf, and http://www.epa.gov/air/particles/2012/tableb.pdf.

Section 110(a)(2) of the Clean Air Act. For a general overview of the NAAQS implementation plans process, see

EPA’s “State Implementation Plan Overview” at http://www.epa.gov/air/urbanair/sipstatus/overview.html.

Section 172 of the Clean Air Act. See EPA’s “State Implementation Plan Overview” at http://www.epa.gov/air/

urbanair/sipstatus/overview.html.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

required to meet any established or revised PM2.5 standard “as expeditiously as practicable,” but

no later than five years from the effective date of designation—December 2020 according to

EPA’s timeline—unless an extension (up to five additional years) allowed under the CAA is

granted.62

National Regulations

EPA anticipates that in many cases, stationary and mobile source controls and additional

reductions currently being adopted to attain existing (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 include the

•

Cross-State Air Pollution Rule (CSAPR);63

•

Mercury and Air Toxics Standards (MATS);64

•

Light-Duty Vehicle Tier 2 Rule;65

•

Heavy Duty Diesel Rule;66

•

Clean Air Nonroad Diesel Rule;67

•

Regional Haze Regulations and Guidelines for Best Available Retrofit

Technology Determinations;68

•

NOx Emission Standard for New Commercial Aircraft Engines;69

•

Emissions Standards for Locomotives and Marine Compression-Ignition

Engines;70

•

Emission Standards Ignition Engines, Control of Emissions for Nonroad Spark

Ignition Engines and Equipment;71

•

Category 3 Oceangoing Vessels;72

Under Section 172(a)(2)(A) of the CAA, EPA may grant an area an extension of the initial attainment date for one to

five years (in no case later than 10 years after the designation date for the area). A state requesting an extension must

submit an implementation plan (SIP) by the required deadline that includes, among other things, sufficient information

demonstrating that attainment by the initial attainment date is “impracticable.”

76 Federal Register 48208-48483, August 8, 2011.

77 Federal Register 9304-9513, February 16, 2012.

65 Federal Register 6822-6870, February 10, 2000.

65 Federal Register 59896-59978, October 6, 2000.

69 Federal Register 38958-39273, January 29, 2004.

70 Federal Register 39104-39172, July 6, 2005.

70 Federal Register 69644-69687, November 17, 2005.

73 Federal Register 37095-37144, republished June 30, 2008.

73 Federal Register 59034-59380, October 8, 2008.

75 Federal Register 22896-23065, April 30, 2010.

Congressional Research Service

Air Quality: EPA’s 2012 Proposed Changes to the Particulate Matter (PM) Standard

•

Reciprocating Internal Combustion Engines (RICE) National Emissions

Standards for Hazardous Air Pollutants (NESHAPS);73 and

•

New Source Performance Standards and Emissions Guidelines for

Hospital/Medical/Infectious Waste Incinerators Final Rule Amendments.74

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),75 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,76 and the Mercury and Air Toxics Standards

(MATS), which EPA itself has stayed pending reconsideration. On October 5, 2012, the U.S.

Department of Justice filed a petition77 seeking en banc rehearing of the D.C. Circuit’s August 21,

2012, decision regarding the CSAPR. Other remanded rules include the hazardous air pollutant

(“MACT”) standards for boilers and cement kilns. EPA has delayed implementation of the boiler

MACT rules for more than a year and a half while considering changes to the requirements. The

agency has also extended the compliance deadline for the cement kiln MACT by two years.

Potential Impacts of More Stringent PM Standards

Estimates of health and welfare risk reductions and control strategies for areas potentially not in

compliance provide some insights into potential impacts of the June 2012 proposed 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 non-health criteria.78

Nevertheless, coinciding with the PM NAAQS proposed rule in the June 29, 2012, Federal

75 Federal Register 51570-51608, August 20, 2010; Proposed Amendments 77 Federal Register 33812-33857, June

7, 2012.

74 Federal Register 51415, October 6, 2009.

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/FR2011-08-08/pdf/2011-17600.pdf. Explanatory and background material can be found on EPA’s website at

http://www.epa.gov/crossstaterule/actions.html.

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/11-13021390314.pdf. See also U.S. EPA’s website, “Cross-State Air Pollution Rule (CSAPR),” for this decision and other