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Clean Air Issues in the 112th Congress
James E. McCarthy
Specialist in Environmental Policy
November 17, 2011
Congressional Research Service
7-5700
www.crs.gov
R41563
CRS Report for Congress
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Summary
Air quality has improved substantially in the United States in the 40 years of EPA’s Clean Air Act
regulation, but more needs to be done, according to the agency’s science advisers, to protect
public health and the environment from the effects of air pollution. Thus, the agency continues to
promulgate regulations addressing air pollution using authority given it by Congress more than 20
years ago. In the 112th Congress, Members from both parties have raised questions about the cost-
effectiveness of some of these regulations and/or whether the agency has exceeded its regulatory
authority in promulgating them. Others in Congress have supported EPA, noting that the Clean
Air Act, often affirmed in court decisions, has authorized or required the agency’s actions.
EPA’s regulatory actions on greenhouse gas (GHG) emissions have been one focus of
congressional interest. Although the Obama Administration has consistently said that it would
prefer that Congress pass new legislation to address climate change, such legislation now appears
unlikely. Instead, over the last two years, EPA has developed GHG regulations using its existing
Clean Air Act authority. On December 15, 2009, the agency promulgated an “endangerment
finding” for GHGs under Section 202 of the act. Relying on this finding, EPA finalized GHG
emission standards for cars and light trucks on April 1, 2010, and for larger trucks, August 9,
2011. The implementation of these standards, in turn, triggered permitting and Best Available
Control Technology requirements for new major stationary sources of GHGs.
It is the triggering of standards for stationary sources (power plants, manufacturing facilities, etc.)
that has raised the most concern in Congress: legislation has been considered in both the House
and Senate aimed at preventing EPA from implementing these requirements. Since February, the
House has passed H.R. 1, which contained provisions prohibiting the use of appropriated funds to
implement various EPA GHG regulatory activities, and H.R. 910, a bill that would repeal EPA’s
endangerment finding, redefine “air pollutants” to exclude greenhouse gases, and prohibit EPA
from promulgating any regulation to address climate change. In the Senate, H.R. 1 was defeated,
and an amendment identical to H.R. 910 (S.Amdt. 183) failed on a vote of 50-50. In July, the
House considered provisions similar to those in H.R. 1 again in H.R. 2584, the Interior,
Environment, and Related Agencies Appropriations Act for Fiscal Year 2012; action on the bill
was suspended July 28, with more than 150 amendments still pending.
Besides addressing climate change, EPA has taken action on a number of other air pollutant
regulations, generally in response to court actions remanding previous rules. Remanded rules
have included the Clean Air Interstate Rule (CAIR) and the Clean Air Mercury Rule—rules
designed to control the long-range transport of sulfur dioxide, nitrogen oxides, and mercury from
power plants through cap-and-trade programs. Other remanded rules included hazardous air
pollutant standards for boilers and cement kilns (standards referred to as “MACT” standards).
EPA is addressing the court remands through new regulations, three of which have already been
promulgated, but many in Congress view the new regulations as overly stringent. Since the
August recess, the House has passed three bills (H.R. 2250, H.R. 2401, and H.R. 2681) to delay
or revoke the new standards and change the statutory requirements for their replacements.
In addition to the power plant and MACT rules, EPA is also reviewing ambient air quality
standards (NAAQS) for ozone, particulates, and other widespread air pollutants. These standards
serve as EPA’s definition of clean air, and drive a range of regulatory controls. The revised
NAAQS also face opposition in Congress. As passed by the House, H.R. 2401 would amend the
Clean Air Act to require EPA to consider feasibility and cost in setting NAAQS.
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Contents
Introduction...................................................................................................................................... 1
EPA’s Greenhouse Gas Regulations................................................................................................. 2
Legislation on Climate Change........................................................................................................ 5
Emissions from Power Plants .......................................................................................................... 7
Cross-State Air Pollution / Clean Air Interstate Rule (CAIR) ................................................... 8
North Carolina v. EPA......................................................................................................... 8
Effects of the Decision ........................................................................................................ 9
EPA’s CAIR Replacement: The Cross-State Air Pollution Rule ....................................... 10
Judicial and Legislative Options ....................................................................................... 11
The Utility MACT: Addressing Mercury and Other Hazardous Air Pollutants ...................... 12
Background ....................................................................................................................... 12
New Jersey v. EPA ............................................................................................................. 13
Other Mercury / Air Toxics Issues..................................................................................... 13
The Proposed Utility MACT / Mercury and Air Toxics Standards ................................... 14
Cumulative Impacts of EPA Rules .......................................................................................... 15
Air Quality Standards .................................................................................................................... 16
Background.............................................................................................................................. 16
Judicial Reviews...................................................................................................................... 17
CASAC’s Role......................................................................................................................... 21
Adequacy of Monitoring ......................................................................................................... 22
NAAQS Implementation ......................................................................................................... 22
Ozone and PM NAAQS Reviews............................................................................................ 23
Ozone ................................................................................................................................ 23
Particulate Matter (including “Farm Dust”)...................................................................... 24
Other Issues ................................................................................................................................... 25

Tables
Table 1. Status of NAAQS Reviews .............................................................................................. 18

Contacts
Author Contact Information........................................................................................................... 26

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Introduction
In the 112th Congress, interest in air quality issues has been dominated by efforts to prevent the
Environmental Protection Agency (EPA) from promulgating and implementing new emission
control requirements. Often under court order, EPA has used the authorities Congress gave it in
the Clean Air Act of 1970 and subsequent amendments in 1977 and 1990 to address longstanding
issues posed by emissions from mobile sources, electric utilities, and a wide range of industrial
sources.
One focus of congressional interest has been EPA regulatory actions to limit greenhouse gas
(GHG) emissions1 using existing Clean Air Act authority. Some Members, from both sides of the
aisle, have expressed concern that EPA is proceeding with GHG regulations that could have major
economic impacts, without direct congressional authorization, and/or that EPA should delay
taking such action until Congress specifically authorizes it.
The Administration counters that it would prefer for Congress to pass new legislation to control
greenhouse gas emissions, but the Clean Air Act already requires action: a 2007 Supreme Court
decision interpreting EPA’s Clean Air Act authority found that the agency must weigh whether
GHG emissions endanger public health and welfare and, if it concludes that they do, proceed with
regulation.2
The 111th Congress struggled to produce its own approach to climate change. In June 2009, the
House narrowly passed H.R. 2454, a 1,428-page bill addressing a number of interrelated energy
and climate change issues. Among its numerous provisions, the bill would have established cap-
and-trade programs for GHG emissions, beginning in 2012. The Senate did not act, however: two
Senate committees reported bills,3 but the prospect of obtaining 60 votes for either bill appeared
slim, and neither came to the floor.
Issues related to emissions from electric power plants—principally sulfur dioxide (SO2), nitrogen
oxides (NOx), and mercury – have been another focus of interest. Regulations addressing these
emissions were vacated by the D.C. Circuit Court of Appeals in 2008.4 EPA is developing new
regulations to address the court’s concerns. It finalized regulations addressing SO2 and NOx on
July 6, 2011;5 the agency has also proposed regulations for power plant emissions of mercury and

1 Six greenhouse gases, or groups of gases, are addressed by EPA regulatory actions: carbon dioxide (CO2), methane
(CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs). Of
these, carbon dioxide, produced by combustion of fossil fuels, is by far the most prevalent, accounting for 85% of
annual emissions of the combined group when measured as CO2 equivalents.
2 Massachusetts v. EPA, 549 U.S. 497 (2007).
3 The Environment and Public Works Committee reported S. 1733, and the Energy and Natural Resources Committee
reported S. 1462.
4 North Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008) addressed the sulfur dioxide and nitrogen oxides regulations,
and New Jersey v. EPA, 517 F.3d 574 (D.C. Cir. 2008) addressed the mercury regulations.
5 The final rule appeared in the Federal Register August 8, 2011. See U.S. Environmental Protection Agency, “Federal
Implementation Plans: Interstate Transport of Fine Particulate Matter and Ozone and Correction of SIP Approvals,” 76
Federal Register 48208, August 8, 2011. Explanatory material can be found at http://www.epa.gov/crossstaterule/
actions.html. The rule is generally referred to as the Cross-State Air Pollution Rule.
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other hazardous air pollutants, under a consent agreement, on March 16, 2011;6 the agency
expects to finalize these standards by December 16.
The Obama Administration’s EPA has also reviewed several Bush Administration and earlier
decisions regarding national ambient air quality standards (NAAQS), as it is required to do by
Section 109 of the Clean Air Act. NAAQS represent EPA’s formal judgment regarding how clean
the air must be to protect public health and welfare; the standards set in motion monitoring and
planning requirements, which in turn lead to designation of “nonattainment areas” and the
imposition of emission controls.
• On January 19, 2010, the agency proposed a more stringent NAAQS for ozone,
having concluded that a 2008 revision to the standard did not satisfy the
requirements of the Clean Air Act. As proposed, the NAAQS was projected to
have both costs and benefits in the tens of billions of dollars. Amid heavy
lobbying on both sides of the issue, EPA sent a final decision to the Office of
Management and Budget for interagency review in July 2011. At the President’s
request, EPA withdrew the decision on September 2, 2011, and resumed
implementation of the 2008 standard.
• On June 22, 2010, the agency promulgated revisions to the NAAQS for SO2; 59
counties would violate the new SO2 standard, based on the most recent
monitoring data.7 None violated the old standard.
• The agency is also reviewing or has recently completed reviews of the NAAQS
for four other pollutants, notably particulate matter (PM), which are emitted by a
wide range of mobile and stationary sources. A revised PM standard is expected
to be proposed by the end of 2011. Early indications are that the agency may
propose a substantially more stringent fine particulate (PM2.5) standard.8
This report provides a brief overview of the climate change, power plant, and air quality standard
issues. More detailed information on most of the issues can be found in other CRS reports, which
are referenced throughout this report.
EPA’s Greenhouse Gas Regulations
EPA’s actions to regulate GHG emissions stem from more than a decade of petitions and
litigation. Responding to a 1999 petition that it regulate greenhouse gases from new motor
vehicles, the agency in 2003 denied that it had such authority, arguing that GHGs did not fall

6 U.S. EPA, “Reducing Toxic Air Emissions from Power Plants,” at http://www.epa.gov/airquality/powerplanttoxics/
actions.html.
7 The number of counties that will be formally designated nonattainment is likely to be different from the 59 EPA
identified, for two reasons. First, EPA promulgated changes to the monitoring requirements along with the new
standard. Second, the actual designations will most likely be made based on 2009-2011 monitoring data, whereas the
59 counties were identified using 2007-2009 data.
8 On April 22, 2011, EPA released its Final Policy Assessment for the Review of the Particulate Matter NAAQS. The
assessment represents EPA staff’s recommendations to the Administrator. It outlined options for revising both the fine
and coarse particulate standard, both of which could make the standards more stringent. The report is available at
http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_2007_pa.html. Information on the status of all of the NAAQS
revisions can be found below in the section of this report entitled “Air Quality Standards.”
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within the Clean Air Act’s definition of “air pollutants.” The denial was challenged by
Massachusetts, 11 other states, and various other petitioners in a case that ultimately reached the
Supreme Court. In an April 2, 2007 decision (Massachusetts v. EPA), the Court found by 5-4 that
EPA does have authority to regulate greenhouse gas emissions, since the emissions are clearly air
pollutants under the Clean Air Act’s definition of that term.9 The Court’s majority concluded that
EPA must, therefore, decide whether emissions of these pollutants from new motor vehicles
contribute to air pollution that may reasonably be anticipated to endanger public health or
welfare, or provide a reasonable explanation why it cannot or will not make that decision, such as
that there is insufficient information to make the decision. If it makes an “endangerment finding,”
the act requires the agency to establish standards for emissions of the pollutants.
On December 15, 2009, acting in response to the Court’s decision, EPA finalized an
endangerment finding for greenhouse gas emissions from motor vehicles, under Section 202(a) of
the act.10 Relying on this finding, EPA finalized GHG emission standards for new cars and light
trucks, April 1, 2010.11 The implementation of these standards has, in turn, triggered permitting
requirements and the imposition of Best Available Control Technology for new major stationary
sources of GHGs beginning January 2, 2011. (For information on these regulations and permit
requirements, see CRS Report R40506, Cars, Trucks, and Climate: EPA Regulation of
Greenhouse Gases from Mobile Sources, and CRS Report R41212, EPA Regulation of
Greenhouse Gases: Congressional Responses and Options.)
The prospect of GHG standards for motor vehicles, which will affect cars and light trucks
beginning in model year 2012, has not been particularly controversial. On May 19, 2009,
President Obama announced an agreement involving nine U.S. and foreign auto manufacturers;
the federal government; the governors of California, Michigan, and Massachusetts; the United
Auto Workers; and environmental groups under which EPA and the National Highway Traffic
Safety Administration (NHTSA) would proceed with a joint rulemaking in which GHG emissions
from new motor vehicles would be reduced under the Clean Air Act, while NHTSA would set
corresponding fuel economy standards under the Corporate Average Fuel Economy (CAFE)
program.12 The objective of the new greenhouse gas standards is to reach reduction levels similar
to those adopted by the state of California and 13 other states, who will harmonize their standards
with those of EPA as part of the agreement. The California standards required about a 30%

9 Massachusetts v. EPA, 549 U.S. 497 (2007). The majority held: “The Clean Air Act’s sweeping definition of ‘air
pollutant’ includes ‘any air pollution agent or combination of such agents, including any physical, chemical ...
substance or matter which is emitted into or otherwise enters the ambient air.... ‘ ... Carbon dioxide, methane, nitrous
oxide, and hydrofluorocarbons are without a doubt ‘physical [and] chemical ... substances[s] which [are] emitted into ...
the ambient air.’ The statute is unambiguous.” For additional discussion, see CRS Report RS22665, The Supreme
Court’s Climate Change Decision: Massachusetts v. EPA, by Robert Meltz.
10 74 Federal Register 66496. While generally referred to as the “endangerment finding” (singular), the Federal
Register notice consists of two separate findings: a Finding that Emissions of Greenhouse Gases Endanger Public
Health and Welfare, and a Finding that Greenhouse Gases From Motor Vehicles Cause or Contribute to the
Endangerment of Public Health and Welfare.
11 The standards appeared in the Federal Register May 7, 2010 at 75 Federal Register 25324. For additional
information, including a link to the standards, see http://www.epa.gov/otaq/climate/regulations.htm#finalR.
12 The President’s announcement and related documents, including a Notice of Upcoming Joint Rulemaking to
Establish Vehicle GHG Emissions and CAFE Standards, which appeared in the May 22, 2009 Federal Register, and
both the draft and final emission standards can be found at http://www.epa.gov/otaq/climate/regulations.htm. For
additional information, see CRS Report R40166, Automobile and Light Truck Fuel Economy: The CAFE Standards, by
Brent D. Yacobucci, or CRS Report R40506, Cars, Trucks, and Climate: EPA Regulation of Greenhouse Gases from
Mobile Sources, by James E. McCarthy and Brent D. Yacobucci.
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reduction in GHG emissions from new vehicles by 2016. The auto industry supported the national
agreement, in part, to avoid having to meet standards on a state-by-state basis; thus, it has not
supported efforts to block EPA’s motor vehicle GHG standards.
On July 29, 2011, the President announced a similar agreement with 13 U.S. and foreign auto
manufacturers under which harmonized GHG and fuel economy standards will be set for model
years 2017-2025. This second round of standards is expected to lead to an average fuel economy
of 54.5 miles per gallon in 2025. Detailed standards were proposed November 16, 2011.13
EPA has also promulgated GHG emission standards for medium- and heavy-duty trucks. EPA’s
endangerment finding specifically referenced medium- and heavy-duty trucks as among the
sources that contribute to the GHG emissions for which it found endangerment. In addition, the
National Highway Traffic Safety Administration (NHTSA) was required by Section 102 of the
Energy Independence and Security Act of 2007 (EISA, P.L. 110-140) to promulgate fuel economy
standards for medium- and heavy-duty trucks, reflecting the “maximum feasible improvement” in
fuel efficiency. Thus, on August 9, 2011, EPA and NHTSA finalized integrated GHG emission
standards and fuel economy standards for medium- and heavy-duty vehicles.14 The standards will
be phased in between 2014 and 2018. When fully implemented, they will require an average per
vehicle reduction in GHG emissions of 17% for diesel trucks and 12% for gasoline-powered
trucks.
In addition to the motor vehicle GHG standards, EPA has received petitions asking the agency to
regulate GHGs from a variety of other sources, including coal mines, concentrated animal feeding
operations (CAFOs), aircraft, ocean-going ships, nonroad engines and equipment (e.g.,
construction equipment, farm equipment, recreational equipment, forklifts, harbor craft, and lawn
and garden equipment), and fuels. Another petition asks the agency to set National Ambient Air
Quality Standards for seven specific greenhouse gases. The agency has also faced lawsuits
seeking to force it to regulate GHGs from a variety of sources, including power plants, petroleum
refineries, nonroad vehicles and engines, and the Portland cement industry.
The decisions to move forward on GHG standards for new motor vehicles have been seen by
many as precedents for these other potential standards,15 and, indeed, EPA has begun to move
forward on GHG standards for a broader set of emission sources. On December 23, 2010, the
agency announced that it had reached a settlement agreement with 11 states, the City of New
York, the District of Columbia, and 3 environmental groups under which it would propose GHG
emission standards for power plants by July 26, 2011, and for refineries by December 10, 2011,
with promulgation by May 2012 and November 2012 respectively. The power plant deadline was
later extended to September 30; when the agency missed that deadline, negotiations began
regarding a new date for proposal. The agency may also miss the December 2011 deadline for
proposal of refinery standards.

13 http://www.epa.gov/otaq/climate/regulations.htm
14 The standards appeared in the September 15 Federal Register. U.S. Environmental Protection Agency, U.S.
Department of Transportation, “Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and
Heavy-Duty Engines and Vehicles; Final Rules,” 76 Federal Register 57106, September 15, 2011.
15 For a further discussion of these issues, see CRS Report R40984, Legal Consequences of EPA’s Endangerment
Finding for New Motor Vehicle Greenhouse Gas Emissions, by Robert Meltz, CRS Report R40506, Cars, Trucks, and
Climate: EPA Regulation of Greenhouse Gases from Mobile Sources, by James E. McCarthy and Brent D. Yacobucci,
and CRS Report R40585, Climate Change: Potential Regulation of Stationary Greenhouse Gas Sources Under the
Clean Air Act, by Larry Parker and James E. McCarthy.
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Even without EPA decisions on these petitions or the proposal of standards for specific industries,
the adoption of GHG standards for motor vehicles has triggered GHG permit requirements for
new stationary sources, as a result of language in Section 165 of the act. That section requires
preconstruction permits and the imposition of best available control technology for new major
sources of all pollutants “subject to regulation” under the act. The permit requirements began to
take effect January 2, 2011. It is this triggering of standards for stationary sources (power plants,
manufacturing facilities, and others) that appears to have raised the most concern in Congress:
legislation has been considered in both the House and Senate aimed at preventing EPA from
implementing these requirements.
Legislation on Climate Change
Introduced legislation has taken several forms. The broadest legislation (such as Representative
Upton’s and Senator Inhofe’s H.R. 910 / S. 482) would repeal EPA’s endangerment finding,
redefine “air pollutants” to exclude greenhouse gases, prohibit EPA from promulgating any
regulation to address climate change, and prohibit EPA from granting the State of California
future waivers allowing it to control GHG emissions from mobile sources.16 H.R. 910 passed the
House April 7, 255-172. A Senate amendment identical to H.R. 910 (S.Amdt. 183) failed on a
vote of 50-50, April 6.
Some of the other bills or amendments introduced in the 112th Congress would:
• suspend EPA actions regulating stationary source emissions of GHGs for two
years (Senator Rockefeller’s S. 231 and Representative Capito’s H.R. 199).
Senator Rockefeller’s bill, introduced as S.Amdt. 215 to S. 493, a bill dealing
with small business innovation, failed on a vote of 12-88, April 6;17
• enact EPA’s Tailoring Rule into statutory law (Senator Baucus’s S.Amdt. 236).
Senator Baucus’s amendment failed on a vote of 7-93, April 6;
• amend the Clean Air Act to provide that greenhouse gases are not subject to the
act (Representative Blackburn’s H.R. 97);
• prohibit EPA from using funds to implement or enforce cap-and-trade programs
or other requirements pertaining to stationary sources of GHG emissions
(Representative Poe’s H.R. 153);
• prohibit any federal agency, in carrying out any act or program to reduce the
effects of greenhouse gas emissions on climate change, from imposing a fee or
tax on gaseous emissions emitted directly by livestock (Representative
Fortenberry’s H.R. 279); or
• prohibit U.S. regulation of carbon dioxide until China, India, and Russia
implement similar reductions (Senator Vitter’s S. 15).

16 Senator Barrasso’s S. 228 and Representative Walberg’s H.R. 750 are similar to the Upton/Inhofe bill in many
respects, including listing a dozen EPA regulatory actions that would be repealed. In addition, the Barrasso/Walberg
bill would prevent citizens from using common law or civil tort (including nuisance) to seek liability, money damages,
or injunctive relief arising from any potential or actual contribution of a greenhouse gas to climate change.
17 Another amendment that would have provided a two-year moratorium, Senator Stabenow’s and Senator Sherrod
Brown’s S.Amdt. 277, also failed, by a vote of 7-93.
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Meanwhile, EPA has itself promulgated regulations and guidance that delayed the applicability of
requirements for stationary sources of GHGs until 2011 and focused its initial permitting efforts
on the largest emitters, granting smaller sources at least a six-year reprieve.18
Although stand-alone legislation to restrict EPA’s authority has received a great deal of attention,
restricting the agency’s authority to use funds to take specific GHG regulatory actions through
riders on the EPA appropriation seems the more likely avenue by which Congress might limit
EPA action. The overall appropriation bill to which it would be attached might contain other
elements that would make it more difficult to veto. This approach was discussed at some length as
early as 2009, when Senator Murkowski introduced (but ultimately did not offer) S.Amdt. 2530
to the FY2010 Interior, Environment, and Related Agencies Appropriation Act (H.R. 2996). It has
now come forward in several forms in the 112th Congress.
In the current fiscal year, appropriations for EPA and the rest of the government were provided
through early April, 2011, by a series of continuing resolutions. In the House, in February,
language similar to H.R. 153 was added to the Full-Year Continuing Appropriations Act, 2011 bill
(H.R. 1) during floor debate, on a 249-177 vote (H.Amdt. 101). H.R. 153, and H.R. 1 as
amended, would have prohibited EPA funding for implementing or enforcing a greenhouse gas
cap-and-trade program or any other greenhouse gas regulatory requirement on stationary sources
issued or effective after January 1, 2011 (including the permitting requirements that took effect
January 2). However, the Senate failed to pass the bill, 44-56, March 9. The final FY2011 budget
agreement (H.R. 1473) did not include restrictions on EPA’s greenhouse gas regulatory authority.
On July 12, 2011, the House Appropriations Committee took up restrictions on EPA’s greenhouse
gas regulatory authority again, as it marked up H.R. 2584, the FY2012 Interior, Environment, and
Related Agencies Appropriations Bill. As reported by the committee, the bill would prohibit EPA
(during the one-year period following enactment) from requiring the issuance of permits for GHG
emissions from livestock and prohibit requiring the reporting of GHG emissions from manure
management systems; would prohibit the agency from proposing or promulgating New Source
Performance Standards for GHG emissions from electric generating units and refineries; would
declare any statutory or regulatory GHG permit requirement to be of no legal effect; would
prohibit common law or civil tort actions related to greenhouse gases or climate change,
including nuisance claims, from being brought or maintained; and would prohibit the preparation,
proposal, promulgation, finalization, implementation, or enforcement of regulations governing
GHG emissions from motor vehicles manufactured after model year 2016, or the granting of a
waiver to California so that it might implement such standards. The bill came to the House floor
under an open rule during the last week of July, and about 200 amendments were filed for
consideration. Action on the bill was suspended July 28, with more than 150 amendments still
pending.
(For a more detailed discussion of EPA’s regulatory actions and potential congressional responses,
see CRS Report R41212, EPA Regulation of Greenhouse Gases: Congressional Responses and
Options, by James E. McCarthy and Larry Parker. For information on EPA Appropriations, see
CRS Report R41896, Interior, Environment, and Related Agencies: FY2012 Appropriations,

18 The two rules that have these effects are: “Prevention of Significant Deterioration and Title V Greenhouse Gas
Tailoring Rule,” final rule, 75 Federal Register 31514, June 3, 2010; and “Reconsideration of Interpretation of
Regulations that Determine Pollutants Covered by Clean Air Act Permitting Programs,” final rule, 75 Federal Register
17004, April 2, 2010.
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coordinated by Carol Hardy Vincent, and CRS Report R41149, Environmental Protection Agency
(EPA): Appropriations for FY2011, by Robert Esworthy et al.)
Emissions from Power Plants
In addition to climate change, other clean air issues with a shorter time horizon are being
addressed by EPA and have been the subject of congressional action. Many of these have to do
with emissions from electric power plants.
Coal-fired power plants are among the largest sources of air pollution in the United States. Under
the Clean Air Act, however, they have not necessarily been subject to stringent requirements:
emissions and the required control equipment can vary depending on the location of the plant,
when it was constructed, whether it has undergone major modifications, the specific type of fuel
it burns, and, to some extent, the vagaries of EPA enforcement policies. More than half a dozen
separate Clean Air Act programs could potentially be used to control emissions, which makes
compliance strategy complicated for utilities and difficult for regulators. Because the cost of the
most stringent available controls, for the entire industry, could range into the tens of billions of
dollars, utilities have fought hard and rather successfully to limit or delay regulations affecting
them, particularly with respect to plants constructed before the Clean Air Act of 1970 was passed.
As a result, emissions from power plants have not been reduced as much as those from some
other sources. Many plants built in the 1950s and 1960s (generally referred to as “grandfathered”
plants) have little emission control equipment.
Collectively, power plants are large sources of pollution. In 2005, they accounted for 10.2 million
tons of sulfur dioxide (SO2) emissions (70% of the U.S. total), 52 tons of mercury emissions
(46% of the U.S. total), and 3.6 million tons of nitrogen oxides (19% of the U.S. total). Power
plants are also considered major sources of fine particles (PM2.5), many of which form in the
atmosphere from emissions from a wide range of stationary and mobile sources. In addition,
power plants account for about 40% of U.S. anthropogenic emissions of the greenhouse gas
carbon dioxide.
With new ambient air quality standards for ozone, fine particles, and SO2 taking effect, emissions
of NOx and SO2 will necessarily have to be reduced to meet standards.19 (These standards are
discussed below under “Air Quality Standards.”) For more than a decade, mercury emissions
have also been a focus of concern. Mercury emitted by power plants and other sources is
deposited in water bodies and is taken up through the food chain: all 50 states have issued fish
consumption advisories due to mercury pollution, covering 16.8 million acres of lakes, 1.25
million river miles, and the coastal waters of 20 entire states.20 The continuing controversy over
the interpretation of New Source Review requirements for existing power plants (which require
the installation of Best Available Control Technology whenever an existing power plant
undergoes major modifications) has exerted pressure for a more predictable regulatory structure,
as well.

19 NOx contributes to the formation of ozone and fine particles; SO2, besides being a regulated pollutant in its own
right, is among the sources of fine particles.
20 See U.S. EPA, “National Listing of Fish Advisories: Technical Fact Sheet,” September 2009, at http://water.epa.gov/
scitech/swguidance/fishshellfish/fishadvisories/tech2008.cfm#synopsis.
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Thus, some in industry, environmental groups, Congress, and the last three Administrations have
said that legislation addressing power plant pollution in a comprehensive (multi-pollutant)
fashion would be desirable. Such legislation would address the major pollutants on a coordinated
schedule and would rely, to a large extent, on a system such as the one used in the acid rain
program, where national or regional caps on emissions are implemented through a system of
tradable allowances. The key questions have been how stringent the caps should be and whether
carbon dioxide (CO2), the major gas of concern with regard to climate change, would be among
the emissions subject to a cap.
Cross-State Air Pollution / Clean Air Interstate Rule (CAIR)
The Senate Environment and Public Works Committee has voted twice on a multi-pollutant bill
(in 2002 and 2005), but neither of the bills progressed to the Senate floor. In the House, similar
bills have been introduced, but none has progressed to markup. Unable to obtain congressional
approval of its multi-pollutant bill (the “Clear Skies” bill21), on March 10, 2005, the Bush
Administration’s EPA announced that it would use existing Clean Air Act authority to promulgate
final regulations similar to those in the bill for utility emissions of SO2 and NOx in 28 eastern
states and the District of Columbia.22
The Clean Air Interstate Rule (CAIR) established cap-and-trade provisions for SO2 and NOx.23
CAIR covered only the eastern half of the country, but since most of the grandfathered generation
capacity is located in the East and South, EPA projected that nationwide emissions of SO2 would
decline 53% by 2015 and NOx emissions 56%.24 The agency also projected that the rule would
result in $85-$100 billion in health benefits annually by 2015, including the annual prevention of
17,000 premature deaths. CAIR’s health and environmental benefits would be more than 25 times
greater than its costs, according to EPA.
North Carolina v. EPA
CAIR was one of the few Bush Administration environmental initiatives that was generally
supported by environmentalists. It also had broad support in the regulated community. But a
variety of petitioners, including the state of North Carolina, which argued that the rule was not
strong enough to address pollution from upwind sources, and some individual utilities that felt
they were unfairly treated by the rule’s emission budgets, challenged the rule in the D.C. Circuit,
and the court vacated it July 11, 2008. A unanimous court found that although EPA had
established a “significant contribution” made by power plants to nonattainment of standards and

21 President Bush first proposed the Clear Skies Act on February 14, 2002, and the bill was introduced by request in the
107th Congress as H.R. 5266/S. 2815. In the 109th Congress, a somewhat modified Clear Skies bill, introduced as S.
131, was considered by the Environment and Public Works Committee, but failed to advance, on a 9-9 vote. Clear
Skies was not introduced in the 110th Congress.
22 The rule appeared in the Federal Register two months later. See U.S. EPA, “Ambient air quality standards,
national—Fine particulate matter and ozone; interstate transport control measures,” 70 Federal Register 25162, May
12, 2005.
23 A separate regulation, the Clean Air Mercury Rule (CAMR), promulgated at the same time, established a Clear-
Skies-like cap-and-trade system for mercury emissions. It is described in a separate section below.
24 As compared to nationwide emissions from electric generating units in 2001. Some of the projected reduction would
be due to pre-existing regulations. See U.S. EPA, Office of Air and Radiation, Regulatory Impact Analysis for the Final
Clean Air Interstate Rule, March 2005, pp. 3-3 and 3-4, at http://www.epa.gov/cair/pdfs/finaltech08.pdf.
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failure to maintain standards in downwind states, as required by Section 110 of the Clean Air Act,
the agency’s methodology for establishing emission budgets for each state was unrelated to the
state’s contribution to the nonattainment and maintenance problems in specific downwind
states.25 The court also found that the choice of 2015 for a second phase compliance deadline,
based on technological and economic feasibility, ignored EPA’s statutory mandate. It found the
fuel adjustment factors in the rule (which set more stringent requirements for natural gas- and oil-
fired plants than for coal-fired ones) to be arbitrary and capricious. It concluded: “CAIR’s flaws
are deep. No amount of tinkering ... will transform CAIR, as written, into an acceptable rule.”26
Despite the seemingly high hurdle set by the language the court used, EPA, environmental
groups, and the utility and mining industries asked the court to review its decision. On December
23, 2008, the court modified its decision, allowing CAIR to remain in effect until a new rule is
promulgated by EPA. 27 The court was not specific about how long this process would be allowed
to take, but stated:
Though we do not impose a particular schedule by which EPA must alter CAIR, we remind
EPA that we do not intend to grant an indefinite stay of the effectiveness of this court’s
decision. Our opinion revealed CAIR’s fundamental flaws, which EPA must still remedy.28
Effects of the Decision
There was general agreement among the states, electric utilities, and environmental groups that
something like CAIR should be salvaged.
• Without CAIR, most eastern states would have had huge gaps in their emission
control programs, which would have to be filled by other regulatory measures if
the states are to attain the NAAQS by the statutory deadlines. The states could be
subject to Clean Air Act sanctions, including a suspension of federal highway
funding for new projects, if they fail to adopt such measures.
• For the utilities, CAIR was designed to build on the existing regulatory
framework of cap-and-trade programs under the acid rain program and the “NOx
SIP Call.”29 Anticipating the ability to bank and trade emission allowances under
CAIR, numerous utilities have already installed equipment to meet or exceed
CAIR’s requirements, the first phase of which are now being implemented.
• Environmental groups have argued for a stronger version of CAIR—particularly
its second phase, to be implemented in 2015—but they generally support the
basic approach.

25 North Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008).
26 Id. at 930.
27 North Carolina v. EPA, 550 F.3d 1176 (D.C. Cir. 2008).
28 Ibid.
29 The acid rain program, established by the Clean Air Act Amendments of 1990, established a cap-and-trade program
for sulfur dioxide emissions from electric generating units. Implementation began in 1995. The NOx SIP Call,
implemented in 2004, is a cap-and-trade program for control of nitrogen oxide emissions in the eastern half of the
country.
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EPA’s CAIR Replacement: The Cross-State Air Pollution Rule
On July 6, 2011, EPA finalized a replacement for CAIR, the Cross-State Air Pollution Rule.30 The
Cross-State rule would leave the CAIR Phase 1 limits in place and would set new limits replacing
CAIR’s second phase in 2012 and 2014, up to three years earlier than CAIR would have.
The CAIR Phase 1 rules already appear to be having substantial effects. In 2010, EPA reports,
SO2 emissions from fossil-fueled power plants in the lower 48 states (at 5.1 million tons) were
49% below 2005 levels. NOx emissions from the same sources declined to 2.1 million tons in
2010, 42% less than in 2005.31
The Cross-State Rule would build on these reductions. It would establish a second and third phase
of reductions in 2012 and 2014, with particular emphasis on SO2—emissions of which would
decline to 2.4 million tons in the covered states (73% below 2005 levels) in 2014. The rule will
cover 28 Eastern, Midwestern, and Southern states and the District of Columbia. It is a modified
cap-and-trade rule. It will allow unlimited trading of allowances within individual states.
Interstate trading will be allowed so long as a state remains within 18%-21% of its emissions
caps. Limiting interstate trading is intended to address the D.C. Circuit’s ruling, which found
CAIR’s unlimited interstate allowance trading program unlawful.
In order to insure that the rule is implemented quickly, EPA promulgated a Federal
Implementation Plan (FIP) for each of the states: the FIP specifies emission budgets for each state
based on controlling emissions from electric power plants. States may develop their own State
Implementation Plans and may choose to control other types of sources if they wish, but the
federal plan will take effect until the state acts to replace it.
EPA estimates that the rule will cost the power sector $2.4 billion annually in 2014, but it expects
the benefits to be 50 to 120 times as great—an estimated $120 billion to $280 billion annually.
The most important benefit would be 13,000 to 34,000 fewer premature deaths annually. Avoided
deaths and other benefits occur throughout the East, Midwest, and South, according to EPA, with
Ohio and Pennsylvania benefitting the most.32
Because the agency intended to finalize more stringent ambient air quality standards for ozone (as
discussed below in the Air Quality Standards section of this report), it discussed the possibility of
proposing another interstate air pollution rule in the summer of 2011 to address any additional
emission reductions needed to meet those new standards. It subsequently withdrew the ozone
proposal at the request of the President and has not proposed additional interstate SO2 or NOx
reductions. But it has stated an “ongoing commitment” to consider upwind contributions of
pollution to nonattainment when implementing any future NAAQS revisions.33 With revisions of
both the ozone and particulate matter (PM) standards expected in the next few years, additional
transport rules might be expected.

30 The final rule appeared in the Federal Register August 8. See U.S. EPA, Federal Implementation Plans: Interstate
Transport of Fine Particulate Matter and Ozone and Correction of SIP Approvals,76 Federal Register 48208, August 8,
2011. Background material can be found on EPA’s website at http://www.epa.gov/crossstaterule/actions.html.
31 Data are from EPA’s National Emissions Inventory, at http://www.epa.gov/ttn/chief/trends/.
32 U.S. EPA, Office of Air and Radiation, “Final Air Pollution Cross-State Air Pollution Rule,” Overview Presentation,
undated, pp. 12-14, at http://www.epa.gov/crossstaterule/pdfs/CSAPRPresentation.pdf.
33 U.S. EPA, “Proposed Air Pollution Transport Rule,” Overview Presentation, July 26, 2010, pp. 19-20, at
http://www.epa.gov/crossstaterule/pdfs/TRPresentationfinal_7-26_webversion.pdf.
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State air pollution control agencies, through the National Association of Clean Air Agencies
(NACAA), have argued that substantial further reductions will be necessary if the states are to
attain the ozone standards. Ozone forms through chemical reactions in the atmosphere between
volatile organic compounds and NOx; after decades of focus on VOC reductions, NOx reductions
are believed to be key to attaining a more stringent ozone standard. For NOx, the Phase 1 cap is
45% below baseline, with Phase 2 providing an additional 7% in 2012. The control technology is
clearly available to do more: EPA modeling projects 54% of coal-fired electric generating units in
the region covered by the Cross-State rule to be without the best available NOx control in 2014.34
Assuming that modeling shows that more reductions are needed for the states to attain the new
ozone NAAQS,35 the pressure will be on EPA to strengthen the regulations further.
Judicial and Legislative Options
The D.C. Circuit Court of Appeals will be one venue for further consideration of these issues. At
least 45 parties have filed suit asking the court to review the Cross-State Rule.36 Particular
controversy has surrounded the rule’s emissions budget for Texas, which was not included in the
proposed version of the rule. Since promulgation, EPA has reviewed information submitted by
Texas and increased the state’s SO2 emissions cap by 29%, but the state remains opposed to the
rule.
Congress has also shown interest in the rule. On September 23, the House passed H.R. 2401, 249-
169. Among its provisions, the bill would declare the Cross-State Rule “of no force and effect,”
reinstating the CAIR rule in its place. The bill would require a study of the cumulative impact of
the Cross-State Rule and about a dozen other regulatory actions, would prohibit EPA from
proposing a replacement until three years after completion of the study, would provide at least a
further three years before compliance could be required, and would require that any replacement
rule allow trading of emission allowances among entities in all affected states.
On November 10, the Senate considered S.J.Res. 27, a resolution of disapproval of the Cross-
State Rule under the Congressional Review Act (CRA). If a CRA resolution disapproving a rule is
enacted, the rule cannot take effect, and the agency may not reissue either that rule or any
substantially similar one, except under authority of a subsequently enacted law. S.J.Res. 27 was
rejected by the Senate, 41-56.

34 U.S. EPA, Office of Air and Radiation, Regulatory Impact Analysis (RIA) for the final Transport Rule, June 2011, p.
259, at http://www.epa.gov/crossstaterule/pdfs/FinalRIA.pdf. The technology referred to is selective catalytic reduction
(SCR).
35 This and other references to the new ozone NAAQS refer to the 2008 standard, which is now being implemented.
36 The cases were consolidated as EME Homer City Generation L.P. v. EPA, No. 11-1302 (D.C. Cir. filed Oct. 7,
2011).
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The Utility MACT: Addressing Mercury and Other Hazardous Air
Pollutants
Background
The Clean Air Act also provides authority for EPA to regulate emissions of mercury and other
hazardous air pollutants (HAPs, or “air toxics”) from electric generation units. Much of this
discussion has focused on mercury. Electric generating units account for about half of all mercury
emissions in the United States.
Mercury is a potent neurotoxin that can cause adverse health effects (principally delayed
development, neurological defects, and lower IQ in fetuses and children) at very low
concentrations.37 The principal route of exposure to mercury is through consumption of fish.
Mercury enters water bodies, often through air emissions, and is taken up through the food chain,
ultimately affecting humans as a result of fish consumption. As noted earlier, all 50 states have
issued fish consumption advisories due to mercury pollution, covering 16.8 million acres of lakes,
1.25 million river miles, and the coastal waters of 20 entire states.
Regulation of mercury emissions from coal-fired power plants has a complicated legislative and
regulatory history, dating back to the 1990 Clean Air Act Amendments. EPA was required by that
legislation and a 1998 consent agreement to determine whether regulation of mercury from power
plants under Section 112 of the Clean Air Act was appropriate and necessary. Section 112 is the
section that regulates emissions of hazardous air pollutants. In general, it requires EPA to set
standards based on the Maximum Achievable Control Technology (a term defined with great
precision in the act), and to impose the MACT standards at each individual emissions source. In a
December 2000 regulatory finding, EPA concluded that regulation of mercury from power plants
under Section 112 was appropriate and necessary. The finding added coal- and oil-fired electric
generating units to the list of sources of hazardous air pollutants, and triggered other provisions of
the 1998 consent agreement: the agency was to propose MACT standards for them by December
15, 2003, and finalize the standards by March 15, 2005.
Rather than promulgate MACT standards, however, EPA reversed its December 2000 finding in
March 2005, and established through regulations a national cap-and-trade system for power plant
emissions of mercury, the Clean Air Mercury Rule (CAMR). Under CAMR, the final cap would
have been 15 tons of emissions nationwide in 2018 (about a 70% reduction from 1999 levels,
when achieved). There would also have been an intermediate cap of 38 tons in 2010, well above
EPA’s projection of emissions in that year.38
Under the cap-and-trade system, utilities could either control the pollutant directly or purchase
excess allowances from other plants that instituted controls more stringently or sooner than
required. As with the acid rain and CAIR cap-and-trade programs, early reductions under CAMR
could have been banked for later use, which the agency itself said would result in utilities

37 For a discussion of mercury’s health effects, see CRS Report RL32420, Mercury in the Environment: Sources and
Health Risks, by Linda-Jo Schierow.
38 The agency projected emissions at 31 tons in 2010 even if 99% of the generating units installed no mercury control
equipment.
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delaying compliance with the full 70% reduction until after 2025.39 (For additional information
on the mercury rule, see CRS Report RL32868, Mercury Emissions from Electric Power Plants:
An Analysis of EPA’s Cap-and-Trade Regulations, by James E. McCarthy.)
New Jersey v. EPA
The CAMR rule was challenged in petitions for review filed by New Jersey and 16 other states as
well as other petitioners.40 The D.C. Circuit, in a 3-0 decision handed down February 8, 2008,41
vacated the rule. The court found that once the agency had listed electric generating units (EGUs)
as a source of hazardous air pollutants, it had to proceed with MACT regulations under Section
112 of the act unless it “delisted” the source category, under procedures the act sets forth in
Section 112(c)(9). Delisting would have required the agency to find that no EGU’s emissions
exceeded a level adequate to protect public health with an ample margin of safety, and that no
adverse environmental effect would result from any source—a difficult test to meet, given the
agency’s estimate that EGUs were responsible for 46% of mercury emissions from all U.S.
sources at the time. Rather than delist the EGU source category, the agency had maintained that it
could simply reverse its December 2000 “appropriate and necessary” finding, a decision that was
much simpler because there were no statutory criteria to meet. The court found this approach
unlawful. “This explanation deploys the logic of the Queen of Hearts, substituting EPA’s desires
for the plain text of Section 112(c)(9),” the court said in its opinion.42
Other Mercury / Air Toxics Issues
Besides the question of whether EPA complied with the law’s requirements, critics found other
reasons to oppose EPA’s cap-and-trade approach to controlling mercury. One of the main
criticisms has been that it would not address “hot spots,” areas where mercury emissions and/or
concentrations in water bodies are greater than elsewhere. In fact, under a cap-and-trade system,
nothing would prevent emissions from increasing at hot spots.
Many also argued that the mercury regulations should have been more stringent or implemented
more quickly than the cap-and-trade regulations would have required. These arguments found a
receptive audience in the states: about 20 states have promulgated requirements stricter than the
federal Clean Air Mercury Rule program, with several requiring 80% to 90% mercury reductions
before 2010. (For additional information, see archived CRS Report RL33535, Mercury Emissions
from Electric Power Plants: States Are Setting Stricter Limits, by James E. McCarthy.)
Another shortcoming of the 2005 Clean Air Mercury Rule was that it didn’t address emissions of
hazardous air pollutants other than mercury. In the analysis accompanying EPA’s current
proposal, the agency states that EGUs are sources of 12 other HAPs, including three acid gases
and nine toxic metals.

39 U.S. EPA, Mercury RIA, previously cited, Table 7-3, p. 7-5.
40 Seven other states joined EPA in defending the rule.
41 New Jersey v. EPA, 517 F.3d 574 (D.C. Cir. 2008).
42 Id. at 582.
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The Proposed Utility MACT / Mercury and Air Toxics Standards
On March 16, 2011, EPA responded to the New Jersey v. EPA court decision by proposing what is
referred to as the “Utility MACT” or, more recently, the Mercury and Air Toxics Standards
(MATS).43 The proposal appeared in the Federal Register on May 3, beginning a public comment
period that ran through August 4. Public hearings have been held in Atlanta, Chicago, and
Philadelphia, and the agency is reported to have received 960,000 public comments. Under a
consent agreement, the final MACT standards are to be promulgated by December 16, 2011.
The Utility MACT would require coal-fired power plants to achieve a 91% reduction from
uncontrolled emissions of mercury, nine other toxic metals, and three acid gases, all of which
were listed by Congress as hazardous air pollutants in the 1990 Clean Air Act Amendments.
Power plants are the largest emitters of many of these pollutants, accounting for about 50% of the
nation’s mercury emissions, 62% of its arsenic emissions, and 82% of its hydrochloric acid
emissions, for example.44 The Utility MACT will also reduce emissions of fine particulates
(PM2.5).
In proposing the standards, EPA noted that while the requirements are stringent for those facilities
lacking controls, 56% of existing coal-fired power plants already are equipped with controls that
allow them to meet the standards. Thus, the standards are expected to level the playing field,
bringing older, poorly controlled plants up to the standards being achieved by a majority of the
existing units.45 In this respect, the proposed standards reflect the statute’s requirement that
existing sources of HAPs should meet standards based on the current emissions of the best
performing similar sources.
EPA projects the annual cost of compliance with the proposed rule at $10.9 billion. The average
consumer would see an increase of $3-$4 per month in the cost of electricity due to the rule,
according to the agency. These costs will go largely to the installation of scrubbers and fabric
filters. As a result of the rule, 26 gigawatts (GW) of coal-fired units, about 9% of total coal-fired
capacity, are expected to install scrubbers. (EPA estimates that 203 GW will have installed
scrubbers anyway, as a result of other regulations.)
More than half of the coal-fired EGU capacity (166 GW) are expected to add fabric filters
because of the rule, while 77 GW would have them in the base case. In most cases, the fabric
filters will be coupled with activated carbon injection or dry sorbent injection. Mercury and other
HAPs become attached to the carbon or sorbent after it is injected into the flue gas, and the fabric
filter collects the particles, removing them from the plant’s emissions.
This is not complicated or new technology. Other types of facilities (notably solid waste
incinerators) have used this technology for the past 15 years to reduce their mercury emissions by
95% or more. As a result of state-level pollution control regulations, a growing percentage of
coal-fired plants do the same. EPA estimates that 62 GW of coal-fired capacity (about one-fifth of

43 For a link to the proposed rule as well as explanatory material, see U.S. EPA, “Reducing Toxic Air Emissions from
Power Plants,” at http://www.epa.gov/airquality/powerplanttoxics/actions.html.
44 See U.S. EPA, “Emissions Overview: Hazardous Air Pollutants in Support of the Proposed Toxics Rule,”
Memorandum from Madeleine Strum, Emission Inventory and Analysis Group, to Marc Houyoux, Group Leader,
Emission Inventory and Analysis Group, March 15, 2011, Tables 3 and 4.
45 The agency also concludes that some plants, representing less than 10 Gw of coal-fired capacity, would be retired by
2015, rather than invest in control technologies. In all, it says, coal-fired generation would decline about 2%.
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the U.S. total) would have either activated carbon or dry sorbent injection in 2015 without the
rule. The rule adds another 149 GW of carbon/sorbent installations.
The benefits of the rule are estimated by EPA at $59 billion to $140 billion annually—5 to 13
times as great as the costs—due primarily to the avoidance of 6,800 to 17,000 premature deaths
each year. Other benefits, only some of which were given dollar values, include the annual
avoidance of 11,000 nonfatal heart attacks, 120,000 cases of aggravated asthma, and
developmental effects on children, including effects on IQ, learning, and memory.
Cumulative Impacts of EPA Rules
As EPA has developed and proposed standards for electric generating units, utilities that rely
heavily on coal-fired power and the industry’s trade association, the Edison Electric Institute
(EEI), have raised concerns about the cumulative impacts of EPA rules. Besides the Cross-State
Rule and the Utility MACT, their attention has focused on proposed Clean Water Act rules for
cooling water intake structures, proposed Solid Waste Disposal Act standards for managing coal
combustion wastes, and soon-to-be-proposed Clean Air Act standards for emissions of
greenhouse gases. Cumulatively, many in the industry and other opponents of these regulations
have begun referring to the rules as an impending “train wreck” for coal-fired power plants. They
maintain that compliance will be difficult and costly within the mandated timeframes, and that, as
a result, sections of the country depending on coal-fired power could experience electricity
reliability problems as plants are retired or taken off-line for retrofit of pollution controls.
Others in the industry and in various think tanks have concluded that this is unlikely to be the
case. They note that the studies sponsored by EEI and by coal-reliant utilities were generally
written before EPA proposed or promulgated any of the actual regulations, and the studies often
assumed far more stringent requirements than EPA actually proposed. While it is true that many
coal-fired units would have to be taken out of service for pollution control equipment to be
installed, the next few years would be an opportune time to do so, as there is currently substantial
excess generating capacity in the electric power industry. This reserve margin will continue to be
available over the next 5-10 years: as a result of the recession and the slow pace of economic
recovery, demand for electricity is growing slowly.
Many observers note, too, that EPA regulation is only one element of the situation facing aging
coal-fired power plants, many of which are more than 40 years old and have few pollution
controls. Equally important is competition from more efficient natural gas combined cycle units,
which have taken over a larger share of the electric power market as the price of natural gas has
declined. Over the last two decades, more than 80% of new generating capacity has come from
these gas-fired units, which are relatively cheap to build and are cleaner and more efficient to
operate than many coal-fired units. Observing the inroads being made by gas-fired generation,
many industry observers conclude that portions of the electric power industry are simply
experiencing a transition to more efficient power generation sources. If the cost of making a coal-
fired plant more efficient and less polluting is higher than that of converting to natural gas, the
plant may well be retired. This can cause economic dislocation in specific communities, but it
might not cause a substantial increase in the price of electricity or threaten the reliability of
electricity supply. For additional information on this subject, see CRS Report R41914, EPA’s
Regulation of Coal-Fired Power: Is a “Train Wreck” Coming?, by James E. McCarthy and
Claudia Copeland.
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Legislation to address the cumulative impacts issue has been introduced in both the House and
Senate. H.R. 2401, the Transparency in Regulatory Analysis of Impacts on the Nation (TRAIN)
Act of 2011, which the House passed September 23, would establish a panel of representatives
from 11 federal agencies to report to Congress by August 2012 on the cumulative economic
impact of a number of listed EPA rules, guidelines, and actions concerning clean air and waste
management. It would render both the Cross-State rule and the Utility MACT “of no force and
effect”; it would reinstate the CAIR rule to replace the Cross-State rule for at least six years
following enactment, and require that any subsequent replacement allow trading of emission
allowances among entities irrespective of the states in which they are located; it would delay
promulgation of a replacement for the Utility MACT until at least one year after submission of
the cumulative impacts report and delay compliance for at least five years after that date; it would
require that the Utility MACT replacement impose the least burdensome regulatory alternative
from among the alternatives authorized under the Clean Air Act; and it would require EPA to take
into consideration feasibility and cost in setting health-based ambient air quality standards.
Language similar to an earlier version of H.R. 2401 was also included in Section 462 of the
reported version of H.R. 2584, the FY2012 Interior and EPA Appropriations bill that was
considered on the House floor during the last week of July. A Senate bill, S. 609, is similar to an
earlier version of H.R. 2401.
Air Quality Standards
Background
Air quality has improved substantially since the passage of the Clean Air Act in 1970: annual
emissions of the six most widespread (“criteria”) air pollutants46 have declined almost 195 million
tons (63%), despite major increases in population, motor vehicle miles traveled, and economic
activity.47 Nevertheless, the goal of clean air continues to elude many areas, in part because
scientific understanding of the health effects of air pollution has caused EPA to tighten standards
for most of the criteria pollutants. Congress anticipated that the understanding of air pollution’s
effects on public health and welfare would change with time, and it required, in Section 109(d) of
the act, that EPA review the standards at five-year intervals and revise them, as appropriate.
The most widespread problems involve ozone and fine particles. As of August 2011, 118 million
people lived in areas classified “nonattainment” for the ozone National Ambient Air Quality
Standard (NAAQS);48 70 million lived in areas that were nonattainment for the fine particle
(PM2.5) NAAQS.49 EPA attributes at least 33,000 premature deaths and millions of lost work days

46 The six criteria air pollutants are ozone, particulate matter, sulfur dioxide, carbon monoxide, nitrogen dioxide, and
lead. Criteria pollutants, identified by the EPA Administrator, are pollutants that (a) cause or contribute to air pollution
which may reasonably be anticipated to endanger public health or welfare, and (b) the presence of which in the ambient
air results from numerous or diverse mobile or stationary sources (Section 108(a)(1) of the Clean Air Act).
47 See U.S. EPA, “Air Emissions Summary Through 2005,” at http://www.epa.gov/air/airtrends/2006/
emissions_summary_2005.html, updated with data from 2009 in U.S. EPA, “Air Quality Trends,” at
http://www.epa.gov/airtrends/aqtrends.html#comparison.
48 Data for ozone nonattainment areas are from the U.S. EPA “Green Book,” at http://www.epa.gov/oar/oaqps/greenbk/
gntc.html.
49 Fine particles, as defined by EPA, consist of particulate matter 2.5 micrometers or less in diameter, abbreviated as
PM2.5. Data for PM2.5 nonattainment areas are also from the U.S. EPA “Green Book,” at http://www.epa.gov/oar/oaqps/
(continued...)
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annually to exceedances of the PM2.5 standard. Recent research has tied ozone pollution to
premature mortality as well.
Violations of the ambient air quality standards for the other four criteria pollutants are not as
widespread, but EPA is engaged in (or has recently completed) reviews indicating that health
effects of most of these pollutants are more serious than previously thought. At present, for
example, no areas exceed the NAAQS for sulfur dioxide (SO2), but in a recent review, EPA
determined that between 2,300 and 5,900 premature deaths can be avoided annually by
strengthening that standard. Thus, the agency has promulgated a new SO2 standard under which
as many as 59 counties could be designated nonattainment, based on the most recent monitoring
data.50
Table 1 summarizes EPA’s recent efforts to review the NAAQS and implement revisions,
including the next steps for each of the six criteria pollutants. Reviews of all six pollutants
(ozone, PM, lead, NO2, carbon monoxide, and SO2) have been completed since 2006, with the
standards being made more stringent for five of the six.51 The next round of reviews has begun
for ozone, PM, and lead.
Reviews don’t always lead to revision of the standards. On August 31, 2011, the EPA
Administrator completed a review of the carbon monoxide (CO) NAAQS without changing the
standard. The CO standard was promulgated in its present form in 1971.
Judicial Reviews
As the table indicates, court challenges have played a key role in bringing about the NAAQS
reviews, and in causing further review after the NAAQS have been promulgated. Reviews of
most of the standards were stimulated at least in part by court cases: because EPA is statutorily
required to review the NAAQS every five years, its failure to do so can be addressed by citizen
suits.
At the other end of the process, once the agency’s review of a NAAQS is completed, the
standards are almost invariably challenged in court. In the case of both particulate matter (PM)
and ozone, judicial review led to a remand of the standards that EPA promulgated in 2006 and
2008 respectively.

(...continued)
greenbk/rnsum.html.
50 http://www.epa.gov/air/sulfurdioxide/pdfs/20100602map0709.pdf. The 59 potential nonattainment counties were
identified using the most recent available monitoring data (2007-2009). EPA is likely to use 2009-2011 or later data
when it comes time to actually designate the areas. Additional monitors will also be sited.
51 Carbon monoxide is the only NAAQS that was left unchanged after review. Four of the six reviews were
subsequently challenged in court and the NAAQS for two of these four (ozone and particulates) were remanded to the
agency for further revisions. There are CRS reports on three of the NAAQS revisions: CRS Report R41062, Ozone Air
Quality Standards: EPA’s Proposed Revisions, CRS Report RL34762, The National Ambient Air Quality Standards
(NAAQS) for Particulate Matter (PM): EPA’s 2006 Revisions and Associated Issues, and CRS Report RL34479,
Revising the National Ambient Air Quality Standard for Lead.
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Table 1. Status of NAAQS Reviews
Monitoring
Pollutant
Last Revision
Court Action?
Next Steps
Issues?
Comments
ozone
Last revision was In response to
States submitted
Only 675 of the
The March 2008
March 27, 2008.
suits filed by 15
proposed
nation’s 3,000
primary (health-
(for additional
Revised
states (Mississippi nonattainment
counties have
based) standards
information, see
standards were
v. EPA), EPA
areas to EPA for
ozone monitors:
were set at a
CRS Report
proposed
agreed to
the 2008
At least 515 of
level less
R41062, Ozone
January 19, 2010, reconsider the
standards in
these counties
stringent than
Air Quality
but withdrawn
March 2008
2009. EPA will
exceeded the
recommended
Standards: EPA’s
September 2,
standards. Court proceed toward
standard
by EPA’s science
Proposed
2011.
review and
designation of
proposed in
advisers. The
Revisions, by
Implementation
areas based on
2010 based on
revision also did
James E.
of the 2008
more recent
the most recent
not act on
McCarthy)
NAAQS were
monitoring data,
monitoring data
proposed
stayed pending
with designations available at that
changes to the
review, but both
expected to be
time. Ozone is
form of the
have resumed
finalized in 2012.
increasingly seen
secondary
following the
as a regional
(welfare)
September 2011

pol utant that
standard that
decision.
EPA has begun
affects rural as
would have
its next five-year
wel as urban
more accurately
review of the
areas, so more
addressed
ozone NAAQS
counties may
impacts on crops
and expects to
need monitors.
and forests. The
propose any
On July 14, 2009, January 2010
changes in 2013.
EPA proposed to proposal would
require that
have addressed
states monitor
both of these
ozone
issues.
concentrations
in rural as well
as urban areas.
particulate
October 17,
The D.C. Circuit EPA expects to
Environmental
October 2006
matter (PM2.5
2006
remanded the
propose
groups would
primary
and PM10)
2006 PM2.5
standards for
like to see
standards for
standards to EPA both PM
additional
PM
(for additional
2.5 and
2.5 were set at
in February 2009 PM
monitoring in
levels less
information, see
10 by the end
(American Farm
of 2011.
areas with
stringent than
CRS Report
Bureau Federation
expected high
recommended
RL34762, The
v. EPA).
In an agency
concentrations
by EPA’s science
National Ambient
document
(e.g., along
advisers.
Air Quality
released April
highways, near
Standards
22, 2011, staff
ports, etc.).
(NAAQS) for
recommended
Particulate Matter
more stringent
(PM): EPA’s 2006
standards.
Revisions and
Associated Issues,
by Robert
Esworthy and
James E.
McCarthy)
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Monitoring
Pollutant
Last Revision
Court Action?
Next Steps
Issues? Comments
sulfur dioxide
On June 22,
The D.C. Circuit EPA intends to
The current SO2 Since 1971, EPA
(SO2)
2010, EPA
remanded the
designate
monitoring
had conducted
revised the
SO2 standard to
nonattainment
network is not
three reviews of
NAAQS,
EPA in 1998,
areas by June
primarily
the SO2 standard
focusing on
following an
2012.
configured to
without changing
shorter-term
agency review
monitor
it.
(1-hour)
that left the
A coalition of
locations of
exposures. The
standard
manufacturers
maximum short-
prior standards
unchanged. The
has sued EPA to
term
(for 24-hour and court found the
overturn the
concentrations.
annual
Administrator
new standards
The network
concentrations),
had failed
(National
needs 41 new
which were
adequately to
Environmental
monitoring sites,
revoked as part
explain her
Development
according to
of the revision,
conclusion that
Association’s
EPA. In a change
were set in
no public health
Clean Air Project
from the
1971. The new
threat existed
v. EPA).
agency’s
short-term
from short term
December 2009
standard is
exposures to
proposal, EPA
substantial y
SO2. (American
will rely
more stringent,
Lung Association
primarily on
replacing a 24-
v. EPA)
dispersion
hour standard of
modeling to
140 parts per
assess
billion (ppb) with
compliance with
a 1-hour
the standard.
maximum of 75
ppb.
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Monitoring
Pollutant
Last Revision
Court Action?
Next Steps
Issues? Comments
carbon
Current primary
The U.S. District EPA’s August
Although it did
Emissions of
monoxide (CO)
standard was set Court for the
2011 decision is
not change the
CO, largely from
in 1971. EPA
Northern
being challenged
standard in its
motor vehicles,
revoked a
District of
by
2011 review,
have declined
secondary
California
environmental
EPA did revise
68% since 1980,
standard in 1985. ordered EPA to
groups
the CO
and no areas
review the CO
(Communities for
monitoring
violate the
NAAQS by
a Better
requirements to
existing CO
August 12, 2011
Environment v.
establish a more
NAAQS, using
(Communities for
EPA).
focused
readings from
a Better
monitoring
the current
Environment v.
network, with
monitoring
EPA). At the
CO monitors to
network.
conclusion of
be placed near
that review, EPA
highly trafficked
Standards for
decided to retain
roads in urban
CO were
the 1971
areas with
retained without
standard.
populations of 1
change despite
million or more
EPA’s science
by 2015 or 2017. advisers having
stated, “There is
consensus in the
Panel that the
current
standards may
not protect
public health
with an adequate
margin of safety,
and therefore
revisions that
result in
lowering the
standards should
be considered.”
nitrogen dioxide
EPA completed a A suit filed in
EPA expects to
Under EPA’s
There are no
(NO2)
review and
2005 charged
identify
new monitoring
nonattainment
promulgated a
that EPA had
nonattainment
network, a
areas for the
new 1-hour
failed to review
areas by January
monitor will be
annual standard,
standard
the NO2
2012. However,
required near a
and only Cook
February 9,
standard in the
the agency
major road in
County, IL
2010. The new
last 5 years, as
believes most
any urban area
(Chicago)
standard is in
required by the
areas will be
with a
violates the new
addition to the
Clean Air Act
“unclassifiable,”
population of
1-hour standard
previous annual
(Center for
due to the lack
350,000 or
using current
average
Biological Diversity of adequate
more. (The
monitoring data.
standard, which
v. Johnson).
monitoring.
majority of NO2
NO2 emissions
was set in 1971. Under a 2007
Once an
emissions come
have been more
consent decree,
expanded
from motor
stringently
EPA proposed
network of NO2
vehicles.)
control ed even
revisions to the
monitors is fully
Community-
though there
primary standard deployed and
wide
have not been
July 15, 2009,
three years of air concentrations
recent violations
and promulgated quality data have
would also be
of the NO2
the revisions in
been col ected,
monitored in
standard,
February 2010.
the agency will
urban areas with
because nitrogen
redesignate
populations of
oxides
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Monitoring
Pollutant
Last Revision
Court Action?
Next Steps
Issues? Comments
areas (in 2016 or 1,000,000 or
contribute to the
2017) based on
more.
formation of
air quality data
ozone, the
from the new
standard for
monitoring
which has been
network.
reviewed and
strengthened
several times.
lead
November 12,
Both
Revised
In July 2009, EPA EPA’s November
2008
environmental
monitoring rules
agreed to review 2008 action
(for additional
groups (which
were proposed
the monitoring
reduced the
information, see
challenged the
December 23,
portions of its
standard by 90%,
archived CRS
adequacy of the
2009.
November 2008
from 1.5
Report RL34479,
monitoring
NAAQS. At
micrograms per
Revising the
requirements)
Sixteen
least 24 of the
cubic meter
National Ambient
and industry
nonattainment
50 states,
(μg/m3) to 0.15
Air Quality
(which
areas were
including some
μg/m3.
Standard for
challenged the
designated in
with major
Lead, by James E.
standard itself)
November 2010. sources of lead
McCarthy)
petitioned for
EPA has begun a
emissions, had
review (Missouri
review of the
no lead monitors
Coalition for the
2008 NAAQS
at all. Under the
Environment v.
and expects to
2008 regulations,
EPA and Coalition
complete it by
101 metro areas
of Battery
2014.
(those with
Recyclers
populations
Association v.
greater than
EPA). EPA
500,000) would
granted a
be required to
petition for
have monitors as
reconsideration
would an
of the
estimated 135
monitoring
areas that have
requirements in
sources of lead
July 2009. In the
emissions
industry case,
greater than or
the D.C. Circuit
equal to one ton
upheld the
per year.
standards, May
Proposed
14, 2010.
regulations
would lower the
source threshold
to 0.5 tons.
CASAC’s Role
In making his decisions regarding the 2008 ozone and 2006 particulate standards, then-EPA
Administrator Stephen Johnson did not follow the advice of the agency’s independent science
advisors, the Clean Air Scientific Advisory Committee (CASAC). The Administrator is not
required by statute to follow CASAC’s recommendations; the act requires only that he set forth in
the Federal Register notice in which he (or she) proposes a NAAQS any pertinent findings,
recommendations, and comments made by CASAC and, if the proposal differs in an important
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respect from any of the recommendations, provide an explanation of the reasons for such
differences.52 But the failure to follow CASAC recommendations almost inevitably raises the
question of whether the Administrator’s decision will be judged arbitrary and capricious in a
judicial review.
In the 2006 and 2008 revisions of the PM and ozone standards, CASAC made detailed objections
to the Administrator’s final decisions. The committee’s description of the process as having failed
to meet statutory and procedural requirements could still play a role during judicial review of the
ozone decision. This raises the question of whether Congress might reconsider CASAC’s
statutory role in the review process, or further specify the conditions under which the
Administrator may reject CASAC’s advice.
Adequacy of Monitoring
A feature common to many of the recent NAAQS reviews has been EPA’s finding that the current
monitoring network is inadequate to determine whether or not many areas of the country are in
attainment of the standards. In several cases, such as for lead and sulfur dioxide, more extensive
monitoring networks had been partly dismantled by the time the standards were reviewed, after
years of indicating compliance with older, less stringent standards.53 In other cases, such as PM
and NO2, the monitoring network was not designed to measure the kinds of exposure that current
research identifies as a cause of concern (e.g., exposure to fine particles near highways). As a
result, EPA and the states will need to devote resources in the next few years to expanding and
refocusing the monitoring networks in order to identify areas where air quality does not meet new
standards.
NAAQS Implementation
Although most of the NAAQS standards had been revised by late 2011—a process that ultimately
will stimulate billions of dollars in expenditures on pollution control—the impact of the new
standards will be gradual. A NAAQS does not directly limit emissions; rather, a primary NAAQS
represents the Administrator’s formal judgment regarding the level of ambient pollution below
which public health will be protected with an adequate margin of safety; a secondary standard
reflects her judgment as to the level of ambient pollution necessary to protect public welfare,
including protection of the environment, water quality, building materials, etc.
Promulgation of a NAAQS sets in motion a lengthy process under which states and the EPA first
identify nonattainment areas. Those areas then undertake a complicated implementation process.
The first step, designation of nonattainment areas, generally takes at least two years after a
standard is promulgated, and in many cases longer, if a new monitoring network needs to be
established. After nonattainment areas are formally designated, the states generally have three
years to submit State Implementation Plans (SIPs) that identify the specific regulations and
emission control requirements that will bring the area into attainment.

52 The requirement is found in Section 307(d)(3) of the act.
53 Also, reductions in EPA grants to the states in some years may have resulted in the elimination of some monitoring
stations. EPA has concluded in some cases that modeling using data from remaining monitors could fill in data gaps.
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Whether more stringent NAAQS will lead to stronger federal emission controls for the sources of
pollution—in addition to the controls contemplated by individual states or metropolitan areas—is
likely to be an important issue. Several of the criteria pollutants have impacts across state lines,
far from the source of emissions; others (notably ozone) form in the atmosphere as the result of
chemical reactions involving precursors that may have been emitted many miles upwind. Thus,
measures taken by individual states and nonattainment areas to control emissions within their
borders may be inadequate for the areas to attain a NAAQS. Federal standards for cars, trucks,
power plants, and other major pollution sources could need strengthening for many areas to be
able to attain the NAAQS.
Ozone and PM NAAQS Reviews
In the last two years, two NAAQS reviews, for ozone and for PM, have proven particularly
controversial. The next sections provide a brief discussion of the two reviews.
Ozone
On January 19, 2010, EPA proposed a revision to the NAAQS for ozone. 54 The proposal did not
follow the usual five-year (or longer) review process, but resulted from the EPA Administrator’s
decision to reconsider standards promulgated in March 2008 by the previous Administration. The
2008 review had made the standards more stringent; but the Obama Administration’s EPA
suspended implementation of the new standard in September 2009 in order to consider further
strengthening it.
As proposed, the January 2010 revision would have lowered the primary (health-based) standard
from 75 parts per billion (ppb) averaged over 8 hours (the standard set in 2008) to somewhere in
the range of 70 to 60 ppb averaged over the same time; it would also have set a new secondary
standard designed to protect crops and forests from ozone. The proposal followed the
recommendations of CASAC, which had concluded that the 2008 revision did not meet the Clean
Air Act’s statutory requirements.
Because of its wide reach and potential cost, the proposed revision was among the most
controversial rules under consideration at EPA over the last two years. Although EPA is
prohibited by the statute55 from considering costs in setting NAAQS, it does prepare cost and
benefit estimates for information purposes. When it proposed the 2010 revisions, the agency
estimated that the costs of implementing the revised ozone NAAQS would range from $19 billion
to $25 billion annually in 2020 if the standard chosen were 70 ppb, or $52 billion to $90 billion if
the standard chosen were 60 ppb,56 with benefits of roughly the same amount. EPA identified at
least 515 counties that would violate the NAAQS if the most recent three years of data available

54 U.S. Environmental Protection Agency, “National Ambient Air Quality Standards for Ozone; Proposed Rule,” 75
Federal Register 2938, January 19, 2010.
55 The Clean Air Act’s Section 108 and Section109 have been so interpreted since the NAAQS provisions were added
to the act in 1970; in 2001, this interpretation was affirmed in a unanimous Supreme Court decision, Whitman v.
American Trucking Associations, 121 S. Ct. 903 (2001).
56 U.S. EPA, “Fact Sheet: Supplement to the Regulatory Impact Analysis for Ozone,” January 7, 2010, at
http://www.epa.gov/air/ozonepollution/pdfs/fs20100106ria.pdf.
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at the time of proposal were used to determine attainment (compared to 85 counties that violated
the 1997 standard in effect at that time).
Initially, the agency said it would complete the ozone review by August 2010, but it announced
delays in the projected completion date four times, before sending a final decision to the Office of
Management and Budget for interagency review in July 2011. The agency’s final decision would
have set a 70 ppb primary standard and would have adopted the new form of the secondary
standard that the agency had proposed. The agency’s cost estimate was unchanged from the
proposal—$19 billion to $25 billion in 2020—and benefits were estimated to be roughly the same
amount.57
On September 2, 2011, the White House announced that the President had requested that EPA
Administrator Jackson withdraw the all-but-final ozone standards from further consideration at
this time. The President’s statement noted that “work is already underway to update a 2006
review of the science that will result in the reconsideration of the ozone standard in 2013,” and
stated that he did not “support asking state and local governments to begin implementing a new
standard that will soon be reconsidered.”58
State and local governments will be asked to begin implementing a new standard that will soon be
reconsidered, however: withdrawal of the decision left EPA and state and local governments to
implement the 2008 ozone standards, which had been stayed pending the agency’s
reconsideration. It also meant that legal challenges to the 2008 standard (Mississippi v. EPA59),
which had been stayed pending reconsideration, can proceed. (For additional information on the
ozone standards, see CRS Report R41062, Ozone Air Quality Standards: EPA’s Proposed
Revisions, by James E. McCarthy.)
Particulate Matter (including “Farm Dust”)
EPA last completed a review of the NAAQS for particulate matter in 2006. The agency is
required by the Clean Air Act to complete a review of the standards at five-year intervals; thus, a
review is due in 2011. In 2009, the D.C. Circuit Court of Appeals remanded the 2006 PM2.5
standards to EPA;60 as a result, EPA is both conducting the statutory five-year review of the
standard and responding to the D.C. Circuit decision.
The current NAAQS sets standards for both “fine” particulates (PM2.5) and larger, “coarse”
particles (PM10). EPA considers particulate matter to be among the most serious air pollutants,
responsible for tens of thousands of premature deaths annually.

57 See U.S. EPA, Regulatory Impact Analysis, Final National Ambient Air Quality Standard for Ozone, July 2011, p.6,
at http://www.epa.gov/airquality/ozonepollution/pdfs/201107_OMBdraft-OzoneRIA.pdf. The costs compared
implementation of a 70 ppb primary standard to the cost of compliance with the 1997 ozone standard. Implementing
the 2008 ozone standard, which the agency will now do, will cost $7.6 billion to $8.8 billion in 2020, according to the
same analysis.
58 The White House, Office of the Press Secretary, “Statement by the President on the Ozone National Ambient Air
Quality Standards,” September 2, 2011.
59 Misissippi v. EPA, No. 08-1200 (D.C. Cir. filed May 23, 2008).
60 American Farm Bureau Fed'n v. EPA, 559 F.3d 512 (D.C. Cir. 2009).
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Of the two types of particulates, the PM2.5 standards affect far more people and far more counties
than the standard for PM10, and both sets of standards have affected mostly industrial, urban
areas. Nevertheless, agricultural interests have made substantial efforts over the last year to assail
a supposed EPA plan to regulate emissions of farm dust through the PM10 NAAQS review, and
have urged Congress to prevent the agency from doing so.
At this time, there is no formal proposal to be evaluated. EPA staff have recommended a
strengthening of the PM NAAQS,61 but the EPA Administrator has not yet published a proposal in
the Federal Register. The Administrator has also stated that she does not intend to change the
PM10 standard as a result of the current review,62 but many Members of Congress from farm
states have been skeptical of EPA’s intentions, and legislation has been introduced to prevent EPA
from doing what it says it does not intend to do.
H.R. 1633, introduced by Representative Noem and cosponsored by 114 Members, would
prohibit EPA from proposing or promulgating revisions to the NAAQS for particulates larger than
2.5 micrometers in diameter for one year. Supporters of the bill describe it as preventing EPA
from promulgating standards that would affect farm dust. Opponents note that the language of the
bill would also prevent EPA from setting standards for particles that are generated by “other
activities typically conducted in rural areas,” a category broad enough that it might include
industrial sources that are located in rural areas, such as power plants. The bill was approved by
the Subcommittee on Energy and Power of the House Energy and Commerce Committee on
November 3. A similar prohibition is contained in Section 454 of the reported version of H.R.
2584. In the Senate, S. 1528 and S. 1803 would address the issue.
For additional information on the PM standards, see CRS Report RL34762, The National
Ambient Air Quality Standards (NAAQS) for Particulate Matter (PM): EPA’s 2006 Revisions and
Associated Issues, by Robert Esworthy and James E. McCarthy.
Other Issues
Over the past two years, EPA has proposed and promulgated numerous regulations implementing
the Clean Air Act (and other pollution control statutes that it administers). Critics of the
Administration, both within Congress and outside of it, have accused the agency of reaching
beyond the authority given it by Congress and ignoring or underestimating the costs and
economic impacts of these rules.At least six bills that would overturn specific regulations or limit
the agency’s authority (H.R. 1, H.R. 910, H.R. 1633, H.R. 2250, H.R. 2401, and H.R. 2681) have
already passed the House. Particular attention has been paid to the Clean Air Act, under which
EPA has moved forward with the first federal controls on emissions of greenhouse gases and has
proposed or promulgated regulations for several major industries.

61 On July 2, 2010, EPA released the Second External Review Draft of its Policy Assessment for the Review of the
Particulate Matter NAAQS. The draft represented EPA staff’s recommendations to the Administrator. It outlined
options for revising both the fine and coarse particulate standard, both of which would make the standards more
stringent. The draft is available at http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_2007_pa.html.
62 Letter of Lisa P. Jackson, EPA Administrator, to Senator Debbie Stabenow, October 14, 2011, at http://epa.gov/pm/
pdfs/20111014Stabenow.pdf. A similar letter was sent to Senator Amy Klobuchar.
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Two of the regulations that have attracted the most attention are the Maximum Achievable
Control Technology standards for boilers and cement kilns (referred to as the “Boiler MACT” and
the “Portland Cement MACT,” respectively). The Portland Cement MACT was promulgated in
September 2010, and compliance with its emission standards is required by November 2013.
Industry has challenged these standards in the D.C. Circuit Court of Appeals (Portland Cement
Association v. EPA), but meanwhile, cement kilns are already negotiating permits based on the
standards and designing and installing equipment needed to comply. A majority of the House
opposes the standards, however, echoing industry’s complaints that the standards are overly
stringent and that the industry needs more time to reduce emissions. On October 6, 2011, the
House passed H.R. 2681, by a vote of 262-161. The bill would revoke EPA’s September 2010
standards as well as standards for commercial and industrial incinerators (to the extent that they
apply to cement kilns), and would require their replacement with standards that represent the least
burdensome regulatory alternative. EPA would be required to set a compliance date no earlier
than six years and three months after the date of enactment.
The boiler standards were proposed June 4, 2010, and finalized February 21, 2011, but EPA itself
says it did not have sufficient time to review all available data submitted by commenters; so it
stayed implementation of the standards May 16 to allow for their reconsideration. The agency
expects to re-propose the standards shortly, and has said it will complete the reconsideration
process by April 30, 2012. Boilers are used as power sources throughout industry and for power
or heat by large commercial establishments and institutions. EPA estimates that the rule, as
promulgated, would provide $22 billion to $54 billion in benefits annually, including the
avoidance of 2,500 to 6,500 premature deaths; but it would also impose annualized costs of $1.4
billion, according to the agency. Opponents of the proposed standard maintain that it would cost
far more. As a result, there is widespread interest in the rule’s requirements and their potential
effects. (For a detailed discussion, see CRS Report R41459, EPA’s Boiler MACT: Controlling
Emissions of Hazardous Air Pollutants, by James E. McCarthy.) Bills have been introduced in
both the House and Senate (H.R. 2250 and S. 1392) to alter the rule’s requirements and delay its
implementation. H.R. 2250 passed the House October 13, 275-142.
Environmental groups disagree that the agency has overreached in setting these rules, and EPA
itself maintains that its pace of regulation under the Clean Air Act is actually slower than the pace
during the first years of the Clinton and George W. Bush Administrations. The agency states that
critics’ focus on the cost of controls obscures the benefits of new regulations, which, it estimates,
far exceed the costs; and it maintains that pollution control is an important source of economic
activity, exports, and American jobs.
For additional discussion of EPA’s regulatory actions, both under the Clean Air Act and under
other statutes, see CRS Report R41561, EPA Regulations: Too Much, Too Little, or On Track?
Author Contact Information

James E. McCarthy

Specialist in Environmental Policy
jmccarthy@crs.loc.gov, 7-7225


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