Order Code RL33776
Clean Air Issues in the 110th Congress:
Climate Change, Air Quality Standards,
and Oversight
Updated March 5, 2007
James E. McCarthy
Specialist in Environmental Policy
Resources, Science, and Industry Division

Clean Air Issues in the 110th Congress:
Climate Change, Air Quality Standards, and Oversight
Summary
Attention to environmental issues in the 110th Congress focused early and
heavily on climate change – the state of the science, and whether (and, if so, how) to
address greenhouse gas emissions. Five bills had been introduced to establish caps
on greenhouse gas emissions as of early March, and hearings on climate change have
been held by at least seven committees. The Speaker of the House set a June
deadline for House committee action on legislation, and established a Select
Committee on Energy Independence and Global Warming to highlight the issue.
Three of the five greenhouse gas bills introduced as of this writing would amend
the Clean Air Act, establishing a new Title VII to address the issue. More such
legislation, as well as free-standing legislation, is likely to be introduced as the
session continues. Whether or not climate change legislation would amend the Clean
Air Act, climate change hearings and markup are among the highest expressed
priorities in the coming months for the committees that have jurisdiction over air
issues (principally the Senate Environment and Public Works and House Energy and
Commerce Committees).
Other clean air issues are less likely to be the main focus of attention, but they
may be addressed, especially through oversight of Administration actions. In general,
EPA regulatory and procedural actions are likely to be more subject to scrutiny in this
Congress, given its intention to reinvigorate the oversight function. Potential
oversight issues include:
! whether EPA’s new standards for ambient concentrations of fine
particulates and its soon-to-be-proposed standards for ozone
adequately reflect the state of the science;
! whether EPA should continue to regulate lead as one of six
pollutants for which it sets national ambient air quality standards;
! whether the EPA’s recently announced changes in the process for
setting ambient air quality standards politicize what traditionally
have been scientific judgments; and
! how best to control emissions of mercury and other pollutants from
electric power plants.
State governments and the courts are also expected to take action on air issues
that may stir congressional interest. Major cases involving climate change, clean air
standards, and the regulation of power plants are pending at the Supreme Court and
the D.C. Circuit Court of Appeals. Decisions in these cases may prompt hearings or
legislation. In addition, states interested in setting more stringent environmental
standards are developing and implementing regulations that go well beyond the
requirements of federal law.

Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Are Greenhouse Gases Air Pollutants? . . . . . . . . . . . . . . . . . . . . . . . . . 3
Should Legislation Focus on Individual Sectors, the Economy as a
Whole, or Both? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Is Cap-and-Trade the Best Approach? . . . . . . . . . . . . . . . . . . . . . . . . . . 4
What Role for Carbon Taxes? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The Role of State Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Other Clean Air Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Revision of the Particulate Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
CASAC’s Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Impacts of the New Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Implementation of the NAAQS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
CASAC’s Role in the NAAQS-Setting Process . . . . . . . . . . . . . . . . . . . . . 13
Revision of the NAAQS for Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Multi-pollutant Legislation for Power Plants . . . . . . . . . . . . . . . . . . . . . . . 16
Mercury From Power Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
New Source Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
List of Figures
Figure 1. Counties Exceeding Revised PM Standards,
2.5
Based on 2003-2005 Monitoring Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
List of Tables
Table 1. Pre-existing, Recommended, and New NAAQS for PM
. . . . . . . . . . . 8
2.5
Table 2. Estimated Costs and Benefits of the EPA’s New PM Standards . . . . 11
2.5

Clean Air Issues in the 110th Congress:
Climate Change, Air Quality Standards, and
Oversight
Introduction
Attention to environmental issues in the 110th Congress focused early and
heavily on climate change. The shift of control from Republicans to Democrats in
the new Congress has altered the political dynamic concerning this issue. Hearings
had been held by at least seven committees as of late February, and five bills to
control greenhouse gases (GHGs) had been introduced, with more expected.
Congress has expressed an interest both in the state of the science and in specific
questions such as whether and, if so, how to reduce greenhouse gas emissions.1 The
Speaker of the House has set a June deadline for House committee action on
legislation, and established a Select Committee on Energy Independence and Global
Warming to highlight the issue.
Three of the five GHG bills introduced as of this writing would amend the Clean
Air Act, establishing a new Title VII to address the issue. (For additional
information on climate change legislation, see CRS Report RL33846, Climate
Change: Greenhouse Gas Reduction Bills in the 110th Congress
, by Larry Parker.)
Whether or not climate change legislation would amend the Clean Air Act, climate
change hearings and markup are among the highest expressed priorities in the coming
months for the committees that have jurisdiction over air issues (principally the
Senate Environment and Public Works and House Energy and Commerce
Committees). Other clean air issues are less likely to be the main focus of attention,
but they may be addressed, especially through oversight of Administration actions.
This report provides a brief overview of the climate change issue as well as
other Clean Air Act issues the 110th Congress may consider.
Climate Change
Climate change (often referred to as global warming) has been of interest to the
Congress on some level for more than 30 years. Hearings on the topic occurred as
early as 1975, with as many as 200 additional hearings since that time. In 1992, the
United States ratified the U.N. Framework Convention on Climate Change
(UNFCCC), which established a goal of reducing greenhouse gas emissions to 1990
levels by the year 2000. In 1997, the parties to the UNFCCC, in order to advance
stronger measures, negotiated binding emission reductions for developed countries
1 CRS has more than a dozen active reports on climate change issues. The reader is referred
to the CRS home page for additional information.

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in the Kyoto Protocol. The United States subsequently rejected the Protocol,
focusing instead on research and on voluntary emission reduction programs.2 Despite
these programs, U.S. emissions of greenhouse gases have continued to climb: in
2005, U.S. emissions were 16% higher than in 1990.3
In recent years, Congress has expressed renewed interest in climate issues for
several reasons. Perhaps the most important factor has been the continued
strengthening of the science supporting the connection between emissions of
greenhouse gases and climate changes, including mounting evidence that glaciers and
polar ice caps are shrinking, global average temperatures are rising, and other
climate-related phenomena are occurring. (For a summary of the science, see CRS
Report RL33849, Climate Change: Science and Policy Implications, by Jane A.
Leggett.) In response, about a dozen states have passed legislation to address the
issue, including California and at least eight Northeastern states. (For a summary of
state actions, see CRS Report RL33812, Climate Change: Action by States To
Address Greenhouse Gas Emissions
, by Jonathan L. Ramseur.) There has also been
a shift in attitude on the part of industry, prompted in part by the growing patchwork
of state-level and foreign requirements. New business coalitions have formed to urge
Congress to address the problem, or to influence any legislation that Congress might
consider.4
Congress was already beginning to respond to these changes before the 2006
elections. In the 109th Congress, the Senate passed a Sense of the Senate resolution
that acknowledged a “growing scientific consensus” that human activity is a
substantial cause of greenhouse gas accumulation in the atmosphere, causing average
temperatures to rise, and called for a mandatory, market-based program to limit
2 The Bush Administration has focused voluntary efforts on reducing the “greenhouse gas
intensity” of the economy, i.e., the amount of greenhouse gases emitted per unit of economic
activity. GHG intensity has consistently declined since the 1970s; but the rate of economic
growth has outpaced the intensity reductions, leading to a steady increase in emissions.
3 World emissions also grew in the period, although comprehensive data for world
greenhouse gas emissions are not available for the same time period. According to the
World Resources Institute, world emissions of CO (not including other greenhouse gases)
2
grew 21% from 1990 to 2003.
4 For example, see “Businesses Call on Congress to Act in 2007,” Daily Environment
Report
, January 23, 2007, p. A-1. The article reported that a coalition of 10 large U.S.
energy and manufacturing firms joined environmental organizations in calling on Congress
to approve legislation in 2007 that would create an economywide cap-and-trade system to
cut the nation's greenhouse gas emissions, saying they would support legislation that would
cap U.S. emissions at 2007 levels by 2012 and gradually reduce them by 60 percent to 80
percent by 2050. The companies included Alcoa, BP America, Caterpillar Inc., Duke
Energy, DuPont, General Electric, Florida Power & Light, the Lehman Brothers global
investment bank, PG&E, and PNM Resources. See also, “Exxon Mobil Greens Up Its Act,”
Fortune, January 26, 2007, which notes: “In its ubiquitous corporate advertising, the
company is talking about what actions should be taken to reduce greenhouse gas emissions,
instead of questioning the science of climate change. ... That's a turnabout from the late
1990s and early 2000s when Exxon led the opposition to the Kyoto Protocols and provided
funding for think tanks that challenged mainstream science.”

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greenhouse gas emissions.5 On a complicated issue such as greenhouse gas limits,
the devil is in the details: agreement on general principles does not necessarily
presage agreement on detailed legislative proposals. One detailed proposal has
reached the Senate floor: the McCain-Lieberman bill (S. 1151 in the 109th Congress,
S. 139 in the 108th) would have established a mandatory, market-based greenhouse
gas reduction program. It was debated in the 109th Congress as an amendment to the
Energy Policy Act of 2005 (S.Amdt. 826) and defeated by a 38-60 vote; as stand-
alone legislation, it was defeated 43-55 in the 108th Congress.6
In the 110th Congress, there appears to be new impetus. In the Senate, the
Chairs of both the Environment and Public Works Committee and the Energy and
Natural Resources Committee have announced their intention to move legislation;
in the House, the Speaker has set a June deadline for committee action. But a
significant number of questions, both procedural and substantive, may need to be
addressed as legislation is considered.
Are Greenhouse Gases Air Pollutants? The relationship of climate
change legislation to the more traditional air pollution programs of the
Environmental Protection Agency (EPA) is one such question. In brief, are
greenhouse gases (particularly carbon dioxide) air pollutants subject to regulation
under the Clean Air Act, or are they more properly considered a side-effect of the use
of fossil fuels to produce energy?
The answer to this question could affect jurisdiction over climate change
legislation (particularly in the Senate, where both the Energy and Natural Resources
Committee and the Environment and Public Works Committee have considered
greenhouse gas legislation). It could determine whether EPA, the Department of
Energy, or some other agency would administer an enacted climate change program.
And it might affect whether states have authority independent of the federal
government to control certain greenhouse gas emissions.
Over the years, EPA has taken both sides of this issue. Under the Clinton
Administration, the agency’s General Counsel argued that CO is an air pollutant, and
2
thus could be regulated under the existing authority of the Clean Air Act. The agency
did not actually propose such regulation; it simply maintained that it would have the
authority to do so if it chose. Under the Bush Administration, a new General
Counsel argued the opposite, maintaining that Congress had clearly distinguished
CO from other air pollutants and, while authorizing research and data collection, had
2
expressly decided not to regulate the pollutant under the existing Clean Air Act. (For
a further discussion of these issues, see CRS Report RL32764, Global Warming: The
Litigation Heats Up
, by Robert Meltz.) The Bush Administration has also intervened
in court to argue that controlling CO and other greenhouse gas emissions from
2
automobiles is equivalent to setting fuel economy standards (a regulatory authority
5 The resolution, which was Section 1612 of the Senate bill (H.R. 6, as amended by S.Amdt.
866), was not included in the enacted version of the bill, P.L. 109-58.
6 The bill that was defeated was S. 139, as amended by S.Amdt. 2028.

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that Congress reserved for the federal government), not controlling air pollution
(where states have a regulatory role).7
As noted, three of the five greenhouse gas reduction bills introduced as of early
March would amend the Clean Air Act. In order to sidestep the complexities of
treating GHGs as traditional pollutants, they establish a new Title VII to establish a
separate program for greenhouse gas emissions. In this respect, the bills emulate the
1990 Clean Air Act Amendments, which established separate titles to deal with acid
precipitation (Title IV) and stratospheric ozone depletion (Title VI).
Should Legislation Focus on Individual Sectors, the Economy as
a Whole, or Both? Most of the bills dubbed “climate change” bills would
establish economy-wide programs to reduce greenhouse gas emissions. But recent
Congresses have also seen dozens of bills aimed at the emissions of individual
sectors, notably electric utilities, cars and trucks, electrical appliances, and
commercial or government buildings. Together, these sectors account for the lion’s
share of energy use and GHG emissions. Electric utilities account for about 40% of
U.S. emissions of CO . Transportation (of which the dominant portion is cars and
2
trucks) accounts for about one-third. Appliances, other electrical equipment, and
buildings all play important roles as consumers of energy; thus, reducing their energy
use through efficiency standards, better insulation, etc., would be important means
of reducing GHG emissions.
If the focus is on individual sectors rather than the economy as a whole, the
likelihood is that legislation would not amend the Clean Air Act, and the resulting
regulatory programs would be implemented and administered by agencies other than
EPA. For example, the Corporate Average Fuel Economy (CAFÉ) standards, which
have regulated the fuel economy of automobiles and light trucks since the mid-1970s,
are set and administered by the National Highway Traffic Safety Administration of
the Department of Transportation. Appliance efficiency standards are set by the
Department of Energy. Other potential elements of a GHG reduction program, such
as building codes, are administered by state and local governments, with little input
from any department or agency of the federal government. Power plants represent
a particularly complicated sector, which, depending on the source of power, may be
regulated by the Nuclear Regulatory Commission, the Federal Energy Regulatory
Commission, or EPA, with a major role also for state governments.
Is Cap-and-Trade the Best Approach? The complexity and sheer number
of measures that might need to be taken in order to have a significant impact on GHG
emissions in sector-specific approaches leads many to suggest an economy-wide
approach, in which a decreasing annual emissions cap is established, and emission
allowances are distributed or sold to major emitters. As the cap (and hence, the
number of allowances) is gradually ratcheted down, markets would determine who
reduces emissions: companies that could do so at low cost would have incentives to
take action; companies with fewer or more costly options could buy allowances to
cover excess emissions. (For a more complete discussion of these issues see CRS
7 For a further discussion of these issues, see CRS Report RL32764, Global Warming: The
Litigation Heats Up
, by Robert Meltz, pp. 10-12.

CRS-5
Report RL33799, Climate Change: Design Approaches for a Greenhouse Gas
Reduction Program
, by Larry Parker.)

Such cap-and-trade programs have an enviable reputation, largely based on the
success of the Clean Air Act’s acid rain program. That program imposed a cap on
sulfur dioxide emissions for a limited number of electric power plants in 1995, and
in 2000 lowered the cap and expanded coverage to more plants. It met its emission
reduction goals at low cost, with virtually 100% compliance, and with minimal
administrative oversight. The success of the program was at least partly the result of
the favorable circumstances in which it was implemented: the reduction targets were
easily met because of an abundant supply of cheap low-sulfur coal; there were only
about 1,000 entities (power plants) covered by the trading program, making it simple
and inexpensive to monitor and administer; and most of the regulated entities were
allowed 10 years to achieve compliance, by which time, early reductions had
generated an enormous number of extra allowances that helped lubricate the trading
system.
Other trading programs have not been as successful. Southern California’s
Regional Clean Air Incentives Market (RECLAIM), for example, which was
implemented in 1994 to reduce emissions of nitrogen oxides (NOx) and sulfur
dioxide (SO ) in the Los Angeles area, saw a 50-fold increase in NOx allowance
2
prices during the 2000-2001 California energy crisis. To permit its continued
functioning and allow utilities to use backup power generators, electric utilities were
removed from the RECLAIM system, charged a flat fee of $15,000 per ton for excess
emissions, and subjected to new command and control requirements (i.e., the type of
regulation the trading system was designed to avoid). The European GHG trading
system, established to help European Union countries meet their Kyoto Protocol
targets, has also seen wild swings in allowance prices, making planning and decision-
making difficult for participating entities.8
A U.S. cap-and-trade system for GHG emissions would face a number of
challenges. First, with the exception of electric utilities, sources of GHGs are not
generally required to monitor or report their emissions; what we know about sources
is based, for the most part, on estimates. Thus, a monitoring requirement would need
to be established to serve as a basis for any future reduction scheme. Second,
decisions would need to be made regarding the comprehensiveness of any program:
what economic sectors to include, what to establish as a small emitter exemption, etc.
Third, there are a wide array of issues related to the distribution or sale of allowances,
including what year to choose as the base year against which to measure emission
reductions; whether to sell allowances to existing sources of emissions or give them
away; whether to establish reserves for new sources; etc. Fourth, in order to prevent
wild swings in allowance prices, some have suggested a “safety valve” – a price at
which the regulatory authority would sell additional allowances if the market cost
rose above predicted levels. Whether to do so and at what price would need to be
determined. Fifth, there are a number of issues related to the question of whether and
how to permit international trading of allowances. Many of the least cost GHG
8 For additional information on the EU trading system, see CRS Report RL33581, Climate
Change: The European Union's Emissions Trading System (EU-ETS)
, by Larry Parker.

CRS-6
reduction options may be in developing countries, but verification of the baseline
emissions and of the continued application of emission controls could pose
challenges to the regulatory authority in such cases. Similar questions are raised by
potential offsets to emissions, in the form of sequestration activities.9
What Role for Carbon Taxes? The complications of establishing a viable
cap-and-trade program suggest to some (especially to those trained in economics)
that the simplest approach to controlling emissions would simply be to impose a
carbon tax. From the point of view of economic efficiency, administrative ease, and
comprehensiveness, a carbon tax has many advantages, but Congress has found it
difficult to impose new taxes, limiting support for this option. It is worth noting that
the “safety valve” discussed in the cap-and-trade section above would function to
some extent like a carbon tax, and might represent a compromise between these two
options.
The Role of State Programs. Finally, as noted earlier, a number of states
have begun programs to reduce GHG emissions. Although the federal government
is challenging some of these, particularly those affecting mobile sources, states do
have clear authority to regulate emissions from power plants, landfills, residential and
commercial buildings, and other sources of GHGs. The extent to which such state
programs might serve as national models is one issue; another is the degree to which
a federal program might preempt state measures affecting similar sources.
Other Clean Air Issues
In addition to climate change, there are a number of clean air issues in which
Congress has expressed an interest. Several of these issues have already been the
subject of oversight hearings.
Despite steady improvements in air quality in many of the United States’ most
polluted cities, the goal of clean air continues to elude many areas. The most
widespread problems involve ozone and fine particles. As of March 2006, 158
million people lived in areas classified “nonattainment” for the ozone National
Ambient Air Quality Standard10; 88 million lived in areas that were nonattainment
for fine particles (PM ).11
2.5
Air quality has improved substantially since the passage of the Clean Air Act
in 1970: annual emissions of the six most widespread (“criteria”) air pollutants have
9 For a broader discussion of issues faced in designing a GHG reduction program, see CRS
Report RL33799, Climate Change: Design Approaches for a Greeenhouse Gas Reduction
Program
, by Larry Parker.
10 Data for ozone nonattainment areas are from the U.S. EPA “Green Book,” at
[http://www.epa.gov/oar/oaqps/greenbk/gntc.html].
11 Data for PM nonattainment areas are also from the U.S. EPA “Green Book,” at
2.5
[http://www.epa.gov/oar/oaqps/greenbk/qntc.html].

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declined 160 million tons (53%), despite major increases in population, motor
vehicle miles traveled, and economic activity.12
Meanwhile, however, scientific understanding of the health effects of air
pollution has caused the EPA to tighten standards for ozone and fine particles. (Fine
particles, as defined by the EPA, consist of particulate matter 2.5 micrometers or less
in diameter, abbreviated as PM .) The agency attributes at least 33,000 premature
2.5
deaths and millions of lost work days annually to exceedances of the PM standard.
2.5
Recent research has begun to tie ozone pollution to premature mortality as well.
Thus, there is continuing pressure to tighten air quality standards: a tightening of the
standard for fine particles was promulgated October 17, 2006. Ozone standards are
scheduled for review in 2007, with new standards to be proposed by May and a final
decision due by February 2008. In addition to the standards themselves, attention has
focused on the major sources of ozone and particulate pollution, such as coal-fired
power plants and mobile sources.
With this background in mind, the remainder of this report provides a discussion
of several interrelated air issues of interest in the 110th Congress, including revision
of the particulate standards, the role of independent scientific review in the setting
of air quality standards, multi-pollutant legislation for electric power plants, mercury
from power plants, and New Source Review. This report provides an overview of
these issues; CRS reports that contain additional information and detailed sources are
referenced in the appropriate sections.
Revision of the Particulate Standards
On September 21, 2006, EPA Administrator Stephen Johnson signed revisions
to the National Ambient Air Quality Standards (NAAQS) for particulate matter.
(The standards appeared in the Federal Register on October 17.13) In developing the
revisions, the EPA reviewed 2,000 scientific studies on particulates and found
associations between particulates and numerous significant health problems,
including aggravated asthma, chronic bronchitis, reduced lung function, irregular
heart beat, heart attacks, and premature death in people with heart or lung disease.
The revisions will strengthen the pre-existing standard for PM , but the
2.5
standard has not been strengthened to the degree recommended by the agency’s staff
or scientific advisors. As shown in Table 1, the new standard cuts the allowable
concentration of PM in the air averaged over 24-hour periods from 65 micrograms
2.5
per cubic meter (µg/m3) to 35 µg/m3; the annual standard, set at 15 µg/m3, does not
change.
12 See U.S. EPA, “Air Emission Trends — Continued Progress Through 2005,” at
[http://www.epa.gov/airtrends/econ-emissions.html].
13 71 Federal Register 61144. Extensive information related to the standards, including an
eight-page fact sheet explaining the standards, and maps and charts with background
material, is available at [http://epa.gov/pm/actions.html].

CRS-8
Table 1. Pre-existing, Recommended, and New NAAQS for PM2.5
Annual Standard
24-Hour Standard
Pre-existing Standardsa
15 µg/m3
65 µg/m3
15 µg/m3 and mid to lower end of 25-35 µg/m3
EPA Staff Recommendation
OR
12-14 µg/m3 and mid to lower end of 30-40 µg/m3
CASAC Recommendation
13 to 14 µg/m3
30 to 35 µg/m3
Administrator’s Decision
15 µg/m3
35 µg/m3
a. Although these standards were promulgated in 1997, they are only now coming into effect, because
of legal challenges, the need to establish a monitoring network, and various administrative
factors. For additional information on implementation of the current standard, see CRS Report
RL32431, Particulate Matter (PM2.5): National Ambient Air Quality Standards (NAAQS)
Implementation
, by Robert Esworthy.
___________________________________________________________________
EPA’s professional staff and the Clean Air Scientific Advisory Committee
(CASAC), a group established by the Clean Air Act to provide independent scientific
advice to the Administrator, had recommended more stringent standards. CASAC
endorsed a 24-hour standard in the range of 30 to 35 µg/m3 and an annual standard
in the range of 13 to 14 µg/m3. Of the 22 CASAC panel members, 20 concurred in
the recommendation.14
In the Administrator’s judgment, the science underlying this recommendation
was not sufficient, relying primarily on two studies, neither of which “provide[s] a
clear basis for selecting a level lower than the current standard....”15 The
Administrator agrees with CASAC that the science shows a relationship between
higher levels of PM and an array of adverse health effects, but he believes there is
2.5
too much uncertainty in the analysis to justify lowering the annual standard.16 He
also noted that the EPA is undertaking substantial research to clarify which aspects
of PM-related pollution are responsible for elevated risks of mortality and morbidity,
including a multi-million-dollar research program whose timeline should permit the
results to inform the Agency’s next periodic reevaluation of the PM standard,
2.5
required by statute within five years. Thus, he concluded, “...it would be wiser to
consider modification of the annual standard with a fuller body of information in
hand than initiate a change in the annual standard at this time.”17
14 By statute, CASAC consists of seven members chosen by the EPA Administrator. To
review the NAAQS for a specific pollutant, CASAC forms a panel that includes as many
subject experts as CASAC deems appropriate, in addition to the seven statutory CASAC
members. Thus, the PM panel had 22 members.
15 U.S. EPA, National Ambient Air Quality Standards for Particulate Matter, Proposed Rule,
Preamble, 71 Federal Register 2651, Jan. 17, 2006.
16 See discussion beginning at 71 Federal Register 61172, Oct. 17, 2006.
17 71 Federal Register 2652, Jan. 17, 2006.

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The PM NAAQS also addresses slightly larger, but still inhalable, particles in
the range of 10 to 2.5 micrometers. These are referred to as thoracic coarse
particles
, or PM
. In its last review of the particulate standards (in 1997), the EPA
10-2.5
had regulated these as particles 10 microns or smaller (PM ), a category that
10
overlapped the PM category. Challenged in the D.C. Circuit Court of Appeals, the
2.5
PM standard was remanded to the EPA, the court having concluded that PM is a
10
10
“poorly matched indicator” for thoracic coarse particles because it includes the
smaller PM category as well as the larger particles. In response, in January 2006,
2.5
the EPA proposed a 24-hour standard for PM
. The standard would have been set
10-2.5
at a level of 70 µg/m3, compared with the current 24-hour PM standard of 150
10
µg/m3. The final standards promulgated in October reversed course, leaving in place
the current form of the standard (PM ) and the current level (150 µg/m3). The only
10
change to the PM standard was the revocation of its annual component. The
10
agency argues that it has provided more thorough reasoning in support of the use of
PM as its coarse particle indicator, and believes that its explanation will satisfy the
10
court.
CASAC’s Views. The Administrator’s decisions represent the first time in
CASAC’s nearly 30-year history that the promulgated standards fall outside of the
range of the scientific panel’s recommendations. In a letter dated September 29,
2006, the seven members of CASAC objected to the Administrator’s actions, both
as regards PM and PM . With regard to PM , the letter stated: “CASAC is
10
2.5
2.5
concerned that EPA did not accept our finding that the annual PM standard was not
2.5
protective of human health and did not follow our recommendation for a change in
that standard.”18 The letter noted that “there is clear and convincing scientific
evidence that significant adverse human-health effects occur in response to short-
term and chronic particulate matter exposures at and below 15 µg/m3
,” and noted
that 20 of the 22 Particulate Matter Review Panel members, including all 7 members
of the statutory committee, were in “complete agreement” regarding the
recommended reduction: “It is the CASAC’s consensus scientific opinion that the
decision to retain without change the annual PM standard does not provide an

2.5
‘adequate margin of safety ... requisite to protect the public health’ (as required by
the Clean Air Act) ....
”19
With regard to PM , the letter stated that CASAC was “completely surprised”
10
at the decision to revert to the use of PM as the indicator for coarse particles, noting
10
that the option of retaining the existing daily PM standard was not discussed during
10
the advisory process and that CASAC views this decision as “highly problematic.”
The Administrator is not required by statute to follow CASAC’s
recommendations; the act (Section 307(d)(3)) requires only that the Administrator
set forth any pertinent findings, recommendations, and comments by CASAC (and
the National Academy of Sciences) and, if his proposal differs in an important
respect from any of their recommendations, provide an explanation of the reasons for
such differences. Courts, in reviewing EPA regulations, generally defer to the
18 Letter of Rogene Henderson et al. to Hon. Stephen L. Johnson, EPA Administrator, Sept.
29, 2006, available at [http://www.epa.gov/sab/pdf/casac-ltr-06-003.pdf].
19 Ibid. Italics in original.

CRS-10
Administrator’s judgment on scientific matters, focusing more on issues of
procedure, jurisdiction, and standing. Nevertheless, CASAC’s detailed objections
to the Administrator’s decisions and its description of the process as having failed to
meet statutory and procedural requirements could play a role if the standards are
challenged in court.
Impacts of the New Standard. The EPA is prohibited from taking cost into
account in setting NAAQS, but to comply with an executive order, the agency has
produced a Regulatory Impact Analysis (RIA) analyzing in detail the costs and
benefits of the new PM standards.20 The agency estimates that compliance with the
new PM standard will prevent 1,200 to 13,000 premature deaths annually, as well
2.5
as substantial numbers of hospital admissions and missed work or school days due
to illness.21 The agency actually produced three sets of benefit numbers, based on
three different studies. The study on which the agency seems to have placed the
greatest emphasis, conducted for the American Cancer Society, was used to estimate
that 2,500 premature deaths would be avoided. The other two studies would have
produced higher benefit numbers. The Harvard Six-City Study, for example, was
used to estimate a reduction of 5,700 premature deaths annually, and an “Expert
Elicitation”22 produced a mean estimate of 7,000 premature deaths reduced. Critics
of the rule argue that as many as 30,000 premature deaths could be avoided annually
if the Administrator had chosen the more stringent standards endorsed by CASAC.23
The higher estimate is based on the agency’s Expert Elicitation.
The agency’s RIA estimates the cost of meeting the new standards at $5.4
billion annually in 2020 and, as shown in Table 2, provides a range of benefit
estimates (from $8 billion to $76 billion annually, depending on the number of
avoided deaths, the choice of discount rate, and other factors). A more stringent
alternative (reducing the annual standard to 14 µg/m3) would increase the cost by
about 50%, to $7.9 billion annually, according to the agency, but would nearly double
the estimated benefits.24 Thus, the benefit-cost ratio would be more favorable,
20 [http://epa.gov/pm/actions.html].
21 See “Regulatory Impact Analysis of EPA’s Final Revisions to the National Ambient Air
Quality Standards for Particle Pollution (Particulate Matter),” Fact Sheet, p. 2, at Ibid.
22 In response to recommendations made in a 2002 National Academy of Sciences (NAS)
report, “Estimating the Public Health Benefits of Proposed Air Pollution Regulations,”the
EPA has been exploring ways to improve the characterization of uncertainty in its analyses
of the health benefits of regulations affecting air quality. One suggested method for doing
so was through the use of expert judgment. To solicit such judgment, the EPA used a wide
range of nomination methods to assemble a group of 12 leading experts (8 epidemiologists,
3 toxicologists/health scientists, and 1 clinician) to respond to a question regarding the
change in mortality associated with a defined change in PM concentration. For additional
2.5
information, see Industrial Economics, Incorporated (for U.S. EPA, Office of Air Quality
Planning and Standards), Expanded Expert Judgment Assessment of the Concentration-
Response Relationship Between PM Exposure and Mortality
, Sept. 21, 2006.
2.5
23 “Stronger Soot Rule Could Avert 30,000 Premature Deaths — EPA Report,” E&E News
PM
, Sept. 22, 2006.
24 U.S. EPA, Regulatory Impact Analysis of the 2006 National Ambient Air Quality
(continued...)

CRS-11
Table 2. Estimated Costs and Benefits of the
EPA’s New PM Standards
2.5
($ billion)
Basis of Benefit Estimate
Cost
Benefits
American Cancer Society Study
$5.4
$15 - $17
EPA Expert Elicitation
$5.4
$8 - $76
Source: EPA Regulatory Impact Analysis.
__________________________________________________________________
according to the agency’s analysis, had the Administrator chosen the more stringent
standard.
Using the most recent available monitoring data, the agency identified 143
counties where air quality is worse than allowed under the new standards. Observed
on a map (Figure 1), these areas can seem small compared with the approximately
3,000 counties in the United States, but two factors make the impact of the standards
far larger. First, the number of counties where emissions will need to be controlled
may be two or three times the number of those exceeding the standard, because
“nonattainment areas” include both counties where pollutant concentrations exceed
the standard and those that contribute to exceedance of the standard in adjoining
counties. Entire metropolitan areas tend to be designated nonattainment, even if only
one county in the area has readings worse than the standard. Second, the
nonattainment counties tend to have larger populations than those in attainment: 88
million people (about 30% of the U.S. population) live in the 208 counties designated
nonattainment for the current standard. The new standard may affect an even larger
percentage of the population.
Implementation of the NAAQS. A NAAQS does not directly limit
emissions; rather, it represents the EPA Administrator’s formal judgment regarding
the level of ambient pollution that will protect public health with an adequate margin
of safety. Promulgation of NAAQS sets in motion a process under which states and
the EPA first identify nonattainment areas. After these areas are formally designated
(a process the EPA estimates will take until April 2010 for the revised PM2.5
standard), the states have three years to submit State Implementation Plans (SIPs)
that identify specific regulations and emission control requirements that will bring
the area into attainment. Attainment of the revised standard is to be achieved by
2015, according to the EPA, with a possible extension to 2020.
Issues. A number of issues were raised during consideration of the proposed
standards, and most remain in the wake of the Administrator’s decision. Those who
would like to see stronger standards (including a number of states and environment
and health groups) have focused on the agency’s disregard of CASAC’s recommen-
24 (...continued)
Standards for Fine Particle Pollution (PM2.5), Table ES-1, available at [http://epa.gov/pm/
actions.html].


CRS-12
Figure 1. Counties Exceeding Revised PM Standards,
2.5
Based on 2003-2005 Monitoring Data
Source: U.S. EPA.

CRS-13
dation that the annual PM standard be strengthened. Some industrial and
2.5
agricultural interests, on the other hand, are questioning the agency’s strengthening
of the standard for all fine particles, without distinguishing their source or chemical
composition. The agency’s response to this is that “... studies suggest that many
different chemical components of fine particles and a variety of different types of
source categories are all associated with, and probably contribute to, mortality, either
independently or in combinations.”25 The Clean Air Subcommittee of the Senate
Environment and Public Works Committee held oversight hearings on the PM
proposal on July 13 and July 19, 2006. Thirteen states, the District of Columbia,
electric utilities and other industry groups, groups representing farmers and ranchers,
and several environmental groups have challenged the standards in court.
(For a more detailed discussion of the new NAAQS, see CRS Report RL33254,
Air Quality: EPA’s 2006 Changes to the Particulate Matter (PM) Standard, by
Robert Esworthy and James McCarthy.)
CASAC’s Role in the NAAQS-Setting Process
The completion of the PM NAAQS review was followed in short order by an
EPA announcement, on December 7, 2006, that it will modify the process for setting
and reviewing NAAQS. Sections 108 and 109 of the Clean Air Act establish
statutory requirements for the identification of NAAQS (or “criteria”) air pollutants26
and the setting and periodic review of the NAAQS standards. However, the process
used by the agency is as much the result of 36 years of agency practice as it is of
statutory requirements. In Section 109, for example, the statute establishes a Clean
Air Scientific Advisory Committee to make recommendations to the Administrator
regarding new NAAQS and, at five-year intervals, to make reviews of existing
NAAQS with recommendations for revisions. In practice, EPA staff, not CASAC,
have prepared these reviews, drafting “criteria documents,” which review the science
and health effects of criteria air pollutants, and “staff papers,” which make policy
recommendations. CASAC’s role has been to review and approve these EPA
documents before they went to the agency’s political appointees and the
Administrator for final decisions.
Under the new procedures, the EPA’s political appointees will have a role early
in the process, helping to choose the scientific studies to be reviewed, and CASAC
will no longer have a role in approving the policy staff paper with its
recommendations to the Administrator. CASAC will be relegated to commenting on
the policy paper after it appears in the Federal Register, during a public comment
period. The goal, according to agency officials, is to speed up the review process,
which has consistently taken longer than the five years allowed by statute. “These
improvements, will help the agency meet the goal of reviewing each NAAQS on a
25 EPA, Office of Research and Development, Air Quality Criteria for Particulate Matter,
p. 9-31, as cited in Section II.C. of the Preamble to the Final Particulate Rule. See 71
Federal Register 61162 et seq., Oct. 17, 2006, for additional discussion.
26 Criteria pollutants are pollutants that endanger public health or welfare, in the
Administrator’s judgment, and whose presence in ambient air results from numerous or
diverse sources.

CRS-14
five-year cycle as required by the Clean Air Act, without compromising the scientific
integrity of the process,”27 according to the memorandum that finalized the changes.
The changes concern environmental groups and some in the scientific community,
however, because they appear to give a larger role to the agency’s political appointees
and a smaller role to EPA staff and CASAC.
Although the new NAAQS review procedures will change the role that CASAC
has historically played, CASAC, at first, appeared less concerned with the changes
than some who have advocated on its behalf. When the December 7 decision
memorandum was released, the committee’s Chair said CASAC did not plan to issue
a formal response. In response to a draft of the changes, the committee had made a
number of suggestions, some of which, such as the convening of a science workshop
at the outset of the process to better focus the review, were incorporated into the
decision memorandum. The memorandum also addressed another of CASAC’s
major concerns, that the old process spent too much time compiling an encyclopedic
review of the literature, much of which had little relevance to the policy questions
that needed to be addressed. With respect to EPA taking comments from CASAC
at the same time that it considers comments from the public, CASAC’s Chair was
reported to say, “(S)ome of the members were concerned but most are not, because
it doesn’t change CASAC’s ability to comment.”28
In early February 2007, however, reports circulated that CASAC had changed
its mind. After its first experience with the new NAAQS review process (at a
meeting to consider the NAAQS for lead),29 it was reported that the committee would
compose a letter to the EPA Administrator critical of the new process:
Henderson [CASAC Chair Dr. Rogene Henderson] said that when EPA
first proposed the NAAQS process changes in response to a memo by
Deputy Administrator Marcus Peacock, CASAC had "misunderstood how
it would be implemented."
However, "the full consequences became apparent in the lead meeting,"
she said, with panel members concerned about not being able to review
staff recommendations. The new process "does not allow CASAC time for
appropriate input to evaluate the science," she said.30
27 “Process for Reviewing National Ambient Air Quality Standards,” Memorandum of
Marcus Peacock, Deputy EPA Administrator, to Dr. George Gray, Assistant Administrator,
Office of Research and Development, and Bill Wehrum, Acting Assistant Administrator,
Office of Air and Radiation, Dec. 7, 2006, p. 3, at [http://www.epa.gov/ttn/naaqs/memo_
process_for_reviewing_naaqs.pdf].
28 Comment of Dr. Rogene Henderson, CASAC Chair, in “EPA Adviser Plays Down
Democrats’ Criticism over New NAAQS Changes,” Inside EPA Clean Air Report,
December 14, 2006.
29 A CASAC Review Panel met to consider the Lead NAAQS on February 6-7, 2007.
30 “Advisory Panel to Recommend Stricter Limit for Agency’s Air Quality Standard for
Lead,” Daily Environment Report, February 9, 2007, p. A-1.

CRS-15
Reaction elsewhere has been stronger. Responding to the changes at the time
of their announcement, the incoming Chair of the Environment and Public Works
Committee, Senator Barbara Boxer, called them “unacceptable,” and said the
committee planned to make them a top priority for oversight in the 110th Congress.31
(The committee included them among the topics it considered February 6, 2007, in
a hearing on “Oversight of Recent EPA Decisions.”) Seven Democratic members of
the committee, including Senator Boxer, wrote EPA Administrator Johnson,
December 21, 2006, to express their strong opposition to the changes and to ask him
to “abandon” them.32 Thus, it would not be surprising if the role of CASAC in
NAAQS reviews were the subject of further scrutiny in the 110th Congress.
Revision of the NAAQS for Lead
As a result of a suit filed by the Missouri Coalition for the Environment and
others in May 2004,33 EPA is under court order to complete a review of the NAAQS
for lead by September 1, 2008. The lead NAAQS was promulgated in 1978. Despite
the Clean Air Act requirement that NAAQS be reviewed every five years, a review
of the standard has not been completed since that time.34
In 1978, when the lead standard was promulgated, lead was widely prevalent in
the air, largely because of exhaust from automobiles running on leaded gasoline.
EPA phased out leaded gasoline in the 1980s and early 1990s. As a result, average
concentrations of lead in ambient air have dropped 96%, according to EPA, and there
are now only two nonattainment areas for lead: East Helena, MT, and Herculaneum,
MO, with a combined population of 4,664 people. Both of these towns were sites of
lead smelters that operated for more than 100 years, contaminating air, water, and soil
nearby.
As part of the current lead NAAQS review, EPA completed a Criteria
Document for lead in October 2006 and a first draft of a Staff Paper or “Policy
Assessment” in December 2006. The Criteria Document concluded that lead-related
health effects occur at blood lead levels lower than previously reported, which might
argue for a more stringent NAAQS; but the Staff Paper, noting the dramatic
reductions in airborne lead emissions, the shift in types of sources, and the listing of
lead compounds as hazardous air pollutants (capable of being controlled under a
different section of the Clean Air Act), raised the possibility that EPA would revoke
31 Office of Senator Barbara Boxer, “Boxer Statement on EPA’s Politicization of Clean Air
H e a l t h S t a n d a r d s , ” P r e s s R e l e a s e , D e c e m b e r 8 , 2 0 0 6 , a t
[http://boxer.senate.gov/news/releases/record.cfm?id=266781].
32 Office of Senator Barbara Boxer, “Democratic Members of Senate EPW Committee Warn
EPA on Air Rollbacks,” Press Release, December 21, 2006, at
[http://boxer.senate.gov/news/releases/record.cfm?id=267092].
33 Missouri Coalition for the Environment v. U.S. EPA, 2005 WL 2234579 (E.D. Mo. Sept.
14, 2005).
34 EPA began a lead NAAQS review and issued a Criteria Document in 1986 and a Staff
Paper in 1990, but the agency never completed the review: i.e., there was no final decision
published in the Federal Register.

CRS-16
the lead NAAQS.35 This would leave lead emissions subject to Maximum
Achievable Control Technology and area source standards to be promulgated under
Section 112 of the act.
The possibility that EPA would revoke the lead NAAQS was among the
subjects reviewed by CASAC at a February 6-7, 2007 meeting. As of early March,
the committee has not posted any formal comments, but press reports indicate that
the panel opposed revocation and will recommend instead a strengthening of the
NAAQS.36 This subject was also discussed at a Senate Environment and Public
Works Committee hearing February 6. As noted earlier, the lead NAAQS review is
also the first review being undertaken under EPA’s new NAAQS review procedures,
the implementation of which appears to be generating controversy.
Multi-pollutant Legislation for Power Plants
Besides air quality standards, the major focus of interest among members of
Congress and other policy makers concerned with air quality in recent years has been
the regulation of electric power plants. Coal-fired power plants are among the largest
sources of air pollution in the United States; however, under the Clean Air Act, they
are not necessarily 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, these plants are large sources of pollution. In 2003, power plants
accounted for 10.2 million tons of sulfur dioxide (SO ) emissions (70% of the U.S.
2
total), about 45 tons of mercury emissions (more than 40% 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 (PM ), many of which form in the
2.5
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; these emissions are not subject to federal regulation
but have been the focus of much debate in recent years.
35 See U.S. EPA, “Fact Sheet: First Draft Staff Paper for Lead,” December 2006, p. 3 at
[http://www.epa.gov/ttn/naaqs/standards/pb/s_pb_cr_sp.html].
36 “Advisory Panel to Recommend Stricter Limit for Agency’s Air Quality Standard for
Lead,” Daily Environment Report, February 9, 2007, p. A-1.

CRS-17
With new ambient air quality standards for ozone and fine particles taking
effect, emissions of NOx (which contributes to the formation of ozone) and SO2
(which is among the sources of fine particles) would necessarily have to be reduced
to meet standards. Mercury emissions have also been a focus of concern: 44 states
have issued fish consumption advisories due to mercury pollution, covering 13
million acres of lakes, 765,000 river miles, and the coastal waters of 12 entire states.
The continuing controversy over the interpretation of New Source Review
requirements for existing power plants (discussed below) is also exerting pressure for
a more predictable regulatory structure.
Thus, many in industry, environmental groups, Congress, and the
Administration have said, for several years now, that the time is ripe for legislation
that addresses power plant pollution in a comprehensive (multi-pollutant) fashion.
Such legislation (the Administration version of which is entitled the Clear Skies
Act37) 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 tradeable
allowances. The key questions have been how stringent the caps should be and
whether carbon dioxide (CO ), the major gas of concern with regard to climate
2
change, will be among the emissions subject to a cap.
It is unclear what direction, if any, the 110th Congress will take regarding multi-
pollutant legislation, but bills introduced in previous Congresses have generally
fallen into three groups: (1) the Administration’s Clear Skies bill, which would
regulate three pollutants (SO , NOx, and mercury), give electric generators until 2018
2
to meet the bill’s final emission caps, allow trading of allowances for all three
pollutants, and remove or restrict numerous existing Clean Air Act requirements; (2)
Representative Waxman’s, Senator Leahy’s, and former Senator Jeffords’s bills,
which, although different from each other in many details, regulated four pollutants
(CO in addition to the other three), gave utilities less time (until 2009 or 2010) to
2
make reductions, set more stringent emission caps, did not allow trading of mercury
emission allowances, and generally left existing Clean Air Act requirements in place;
and (3) Senator Carper’s and former Representative Bass’s bills, which essentially
split the difference between the first two groups on the stringency and timing of SO ,
2
NOx, and mercury controls; established a CO control program (but less stringent
2
than the Waxman, Leahy, or Jeffords bills); and generally left existing Clean Air Act
requirements in place. (For additional information and a detailed comparison of
legislative proposals in the last Congress, see CRS Report RL32755, Air Quality:
Multi-Pollutant Legislation in the 109th Congress
, by Larry Parker and John
Blodgett.)
Because the deadlines are far in the future, the Administration’s analysis of
Clear Skies has shown that utilities would be likely to “overcomply” in the early
years of the program. The Administration uses this as a selling point for its approach,
arguing that it will achieve reductions sooner than would a traditional regulatory
37 The Administration first proposed the Clear Skies Act on Feb. 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 was introduced as S. 131.

CRS-18
approach with the same deadlines. However, overcompliance in the early years
would lead to “banked” emission allowances; these could be used in later years to
delay achievement of required reductions. In its analysis of the bill, the EPA does
not expect to see the full 70% emission reductions that it requires until 2026 or later,
a point seized upon by its opponents to support a more aggressive approach.
As noted, the Clear Skies bill includes no cap on CO emissions. The
2
Administration has rejected mandatory controls on CO , in keeping with its
2
opposition to the Kyoto Protocol to the United Nations Framework Convention on
Climate Change. It opposes Kyoto for a variety of reasons, principally the potential
economic impacts on U.S. industries.
The absence of CO from the mix leads to different strategies for achieving
2
compliance, preserving more of a market for coal, and lessening the degree to which
power producers might switch to natural gas or renewable fuels as a compliance
strategy. In its opposition to CO controls, the Administration is supported by most
2
in the utility and coal industries. Others, mostly outside these industries but
including some utilities, view CO controls as inevitable, and perhaps desirable, and
2
support simultaneous implementation of cap-and-trade programs for CO and the
2
other pollutants.
The Senate Environment and Public Works Committee has voted twice on a
multi-pollutant bill, but none of the bills has progressed to the House or Senate floor.
On March 10, 2005, however, EPA announced that it would use existing Clean Air
Act authority to promulgate final regulations similar to the Clear Skies bill for utility
emissions of SO and NOx in 28 eastern states and the District of Columbia.38 The
2
Clean Air Interstate Rule (CAIR) established cap-and-trade provisions that mimic
those of Clear Skies, but the regulations cover only the eastern half of the country,
and, as a regulation, CAIR has no authority to allow the EPA to remove existing
Clean Air Act requirements, as Clear Skies would. Under CAIR, the EPA projects
that nationwide emissions of SO will decline 53% by 2015 and NOx emissions will
2
decline 48%. The agency also projects that the rule will result in $85-$100 billion
in health benefits annually by 2015, including the prevention of 17,000 premature
deaths annually.39 CAIR’s health and environmental benefits are more than 25 times
greater than its costs, according to the EPA. Similarly, any of the multi-pollutant
bills are expected to have benefits far outweighing their costs. (For additional
information on the CAIR rule, see CRS Report RL32927, Clean Air Interstate Rule:
Review and Analysis
, by Larry Parker. For a discussion of the costs and benefits of
the principal multi-pollutant approaches, see CRS Report RL33165, Costs and
Benefits of Clear Skies: EPA’s Analysis of Multi-Pollutant Clean Air Bills
, by James
E. McCarthy and Larry B. Parker.)
38 The rule appeared in the Federal Register on May 12, 2005 (70 FR 25162).
39 U.S. EPA, Office of Air and Radiation, “Clean Air Interstate Rule — Basic Information,”
available at [http://www.epa.gov/interstateairquality/basic.html].

CRS-19
Mercury From Power Plants
On March 15, 2005, the EPA also finalized through regulation a cap-and-trade
program for mercury emissions from electric utilities.40 The mercury regulations
(which, like CAIR, are based on the Clear Skies approach) rely almost entirely on co-
benefits of regulating SO and NOx. The agency’s analysis of the mercury rule finds
2
that less than 1% of coal-fired power plant capacity would install pollution control
equipment specifically designed to control mercury within 10 years as a result of the
mercury rule. By 2020, only 4% of capacity would have such equipment.
The EPA was required by the terms of the 1990 Clean Air Act Amendments 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. It
concluded that it was, in a December 2000 regulatory finding. The finding triggered
other provisions of the consent agreement: that the agency propose Maximum
Achievable Control Technology (MACT) standards for electric power plants by
December 15, 2003, and finalize them by March 15, 2005.
The December 2003 proposal offered two alternatives. The first would have
met the agency’s requirement under the consent agreement by setting MACT
standards. The standards would have applied on a facility-by-facility basis and would
have resulted in emissions of 34 tons of mercury annually, a reduction of about 30%
from the 1999 level. The standards would have taken effect in 2008, three years after
promulgation, with possible one-year extensions.
The second alternative used Section 111(d) of the act. To avoid having to
promulgate MACT standards, which would set limits for each individual facility, the
agency proposed reversing its December 2000 regulatory finding, arguing that
although MACT standards were “appropriate,” they were not “necessary” because
the emissions could be controlled under Section 111(d) instead, a section that allows
a more flexible approach, such as a cap-and-trade program. Section 111(d) has rarely
been used before — and never for hazardous air pollutants.
The final regulations, promulgated March 15, 2005, chose the second approach,
establishing a national cap-and-trade system for power plant emissions of mercury.
The cap will be 15 tons of emissions nationwide in 2018 (about a 70% reduction
from 1999 levels, when achieved). There will also be an intermediate cap of 38 tons
in 2010. The caps will be implemented through an allowance system similar to that
used in the acid rain and CAIR programs, through which utilities can either control
the pollutant directly or purchase excess allowances from other plants that have
instituted controls more stringently or sooner than required. As with the acid rain and
CAIR programs, early reductions can be banked for later use, which the agency says
40 The mercury rule appeared in the Federal Register in two parts: in the first part, on
March 29, 2005 (as explained further in the text below), the agency revised its determination
that mercury emissions from electric generating units should be regulated as hazardous air
pollutants under Section 112 of the Clean Air Act (70 FR 15994); in the second part, on
May 18, 2005, the agency promulgated a cap-and-trade program under Section 111 of the
act (70 FR 28606).

CRS-20
will result in utilities delaying compliance with the full 70% reduction until well
beyond 2018, as they use up banked allowances rather than installing further controls.
The agency’s analysis projects actual emissions to be 24.3 tons (less than a 50%
reduction) as late as 2020. Full compliance with the 70% reduction would be delayed
until after 2025.41 (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.)
Besides the stretched out implementation schedule, one of the main criticisms
of the cap-and-trade proposal is that it would not address “hot spots,” areas where
mercury emissions and/or concentrations in water bodies are greater than elsewhere.
It would allow a facility to purchase allowances and avoid any emission controls, if
that compliance approach makes the most sense to the plant’s owners and operators.
If plants near hot spots do so, the cap-and-trade system may not reduce mercury
concentrations in the most contaminated areas. By contrast, a MACT standard would
have required reductions at all plants, and would therefore be expected to improve
conditions at hot spots.
Many argue that the mercury regulations should be more stringent or
implemented more quickly. To a large extent, these arguments, and EPA’s counter-
arguments, rest on assumptions concerning the availability of control technologies.
Controlling SO , NOx, and mercury simultaneously, as the agency prefers, would
2
allow utilities to maximize “co-benefits” of emission controls. Controls such as
scrubbers and fabric filters, both of which are widely used today to control SO and
2
particulates, have the side effect of reducing mercury emissions to some extent.
Under EPA’s cap-and-trade regulations, both the 2010 and 2018 mercury emission
standards are set to maximize use of these co-benefits. Thus, few controls would be
required to specifically address mercury emissions before the 2020s, the costs
specific to controlling mercury would be minimal, and emissions would decline to
about 50% of the 1999 level in 2020.
Besides citing the cost advantage of relying on co-benefits, the EPA has claimed
that technology specifically designed to control mercury emissions (such as activated
carbon injection, ACI) would not be generally available until after 2010. This
assertion is widely disputed. ACI and fabric filters have been in use on municipal
waste and medical waste incinerators for a decade, and have been successfully
demonstrated in at least 16 full-scale tests at coal-fired power plants, for periods as
long as a year. Manufacturers of pollution controls and many others maintain that
if the agency required the use of ACI and fabric filters at power plants, reductions in
mercury emissions as great as 90% could be achieved at reasonable cost in the near
future. Relying on these assertions, about 20 states have promulgated requirements
stricter than the federal program, with several requiring 80% to 90% mercury
reductions before 2010. (For additional information, see CRS Report RL33535,
Mercury Emissions from Electric Power Plants: States Are Setting Stricter Limits,
by James E. McCarthy.)
41 U.S. EPA, Office of Air Quality Planning and Standards, Regulatory Impact Analysis of
the Clean Air Mercury Rule
, March 2005, Table 7-3, p. 7-5, at [http://www.epa.
gov/ttn/atw/utility/ria_final.pdf].

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It is unclear whether the EPA has legislative authority to establish a cap-and-
trade program for mercury: many argue that the agency is required by the statute to
impose MACT standards on each individual plant once it has decided to control
mercury emissions. Questions also have arisen regarding the role of industry
lobbyists in crafting portions of the EPA proposal. For many of these reasons, 45
Senators wrote EPA Administrator Leavitt at the beginning of April 2004 to request
that he withdraw the mercury proposal and start over. In June, 2004, 178 House
members wrote Leavitt that they hoped further review “will lead to a stronger final
rule.” On February 3, 2005, the EPA Inspector General echoed these comments,
concluding that EPA senior management instructed the staff to develop a standard
that would result in emissions of 34 tons annually, instead of basing the standard on
unbiased analysis. Nevertheless, the agency acted to make the final rule less stringent
rather than strengthening it.42 The agency’s cost-benefit analysis also did not include
several peer-reviewed studies that indicated stricter utility mercury rules would have
yielded large benefits. Thus, opponents, including at least 15 states, have filed suit
to overturn the rule.43
In September 2005, the Senate considered, but narrowly defeated, a challenge
to the rule under the Congressional Review Act.44
New Source Review
A related issue that has driven some of the debate over the regulation of power
plant emissions is whether the EPA has adequately enforced existing regulations,
using a process called New Source Review (NSR). The New Source Review debate
has occurred largely in the courts. The EPA took a more aggressive stance on NSR
under the Clinton Administration, filing lawsuits against 13 utilities for violations at
51 plants in 13 states. The Bush Administration has taken action against an
additional half a dozen utilities but has made little headway in settling the original
suits or in bringing them to trial. In the meantime, it has proposed major changes in
the NSR regulations that critics argue will weaken or eliminate New Source Review
as it pertains to modifications of existing plants.
The controversy over the NSR process stems from the EPA’s application of
New Source Performance Standards to existing stationary sources of air pollution that
have been modified. The Clean Air Act requires that plants undergoing
modifications meet NSR requirements by installing best available pollution controls,
but industry has often avoided the NSR process by claiming that changes to existing
sources were “routine maintenance” rather than modifications. In the 1990s, the EPA
began reviewing records of electric utilities, petroleum refineries, and other industries
42 Office of the Inspector General, U.S. EPA, Additional Analyses of Mercury Emissions
Needed Before EPA Finalizes Rules for Coal-Fired Electric Utilities
, Feb. 3, 2005, p. 10,
available at [http://www.epa.gov/oig/reports/2005/20050203-2005-P-00003.pdf].
43 New Jersey v. EPA, No. 05-1097 (D.C. Cir.) Filed Mar. 29, 2005.
44 For discussion of the Congressional Review Act and how it applied to the mercury rule,
see CRS Report RS22207, Congressional Review of EPA’s Mercury Rule, by James
McCarthy and Richard Beth.

CRS-22
to determine whether the changes were, in fact, routine. As a result of these reviews,
since late 1999, the EPA and the Department of Justice have filed suit or
administrative actions against numerous large sources of pollution, alleging that they
made major modifications to their plants, extending plant life and increasing output,
without undergoing required New Source Reviews and without installing best
available pollution controls.
Of the utilities charged with NSR violations, 11 have settled with the EPA,
generally without going to trial. Under the settlements, they have agreed to spend
about $5 billion over the next decade on pollution controls or fuel switching to
reduce emissions at their affected units. Combined, these companies will reduce
pollution by about 775,000 tons annually. Since July 25, 2000, the agency has also
reached 17 agreements with petroleum refiners representing three-fourths of industry
capacity. The refiners agreed to settle potential charges of NSR violations by paying
fines and installing equipment to eliminate 315,000 tons of pollution.
About half the utilities charged with NSR violations have not settled with the
EPA. They and other critics of the agency’s enforcement actions claim that the EPA
reinvented the rules. They also contend that a strict interpretation of what constitutes
routine maintenance will prevent them from making changes that would have
previously been allowed without a commitment of time and money for permit
reviews and the installation of expensive pollution control equipment. This provides
disincentives for power producers, refiners, and others to expand output at existing
facilities, they maintain.
The first case involving one of the nonsettling utilities went to trial in February
2003. In an August 7, 2003, decision, the U.S. District Court for the Southern
District of Ohio found that Ohio Edison had violated the Clean Air Act 11 times in
modifying its W. H. Sammis power plant. The company subsequently settled the
case, agreeing to spend $1.1 billion to install controls that are expected to reduce
pollution by 212,000 tons annually.45 In a second case, decided in April 2004 and
currently on appeal to the U.S. Supreme Court, Duke Energy was found not to have
violated the act despite undertaking modifications that increased total emissions
without undergoing New Source Review. The U.S. District Court for the Middle
District of North Carolina, in a decision upheld by the Fourth Circuit Court of
Appeals, held that since the maximum hourly emissions rate did not increase as a
result of the modifications, even if annual emissions did increase, the company was
not required to undergo NSR and install more stringent pollution controls.46
While pursuing these enforcement actions, the Bush Administration has
promulgated a number of changes to the NSR regulations that would make future
enforcement of NSR less likely. In December 2002 and October 2003, the agency
promulgated five sets of changes to the NSR rules. The most controversial were new
45 United States v. Ohio Edison Co., No. C-2-99-1181, [S.D. Ohio].
46 United States v. Duke Energy Corp., 278 F.Supp. 2d 619 [M.D.N.C. 2003] affirmed, 411
F. 3d 539 [4th Cir., 2005], petition for cert. Filed [No. 05-848].

CRS-23
regulations defining what constitutes routine maintenance.47 The new regulations
would have exempted industrial facilities from undergoing NSR (and thus from
installing new emission controls) if they were replacing safety, reliability, and
efficiency-rated components with new, functionally equivalent equipment, and if the
cost of the replacement components was less than 20% of the replacement value of
the process unit. Using this benchmark, few, if any, plant modifications would
trigger new pollution controls.
These changes were highly controversial. The Administration and its supporters
characterized them as streamlining or improving the program; others saw them as
permanently “grandfathering” older, more polluting facilities from ever having to
meet the clean air standards required of newer plants. Fifteen states, three
municipalities, and several environmental groups filed suit to block the “equipment
replacement / routine maintenance” rule. The rule was stayed by the U.S. Court of
Appeals for the D.C. Circuit on December 24, 2003. On March 17, 2006, a three-
judge panel of the court unanimously struck the rule down. In its decision, the court
held that the EPA’s attempt to change the NSR regulations was “contrary to the plain
language” of the Clean Air Act.48
The EPA proposed further changes to the NSR regulations on October 20, 2005,
and September 8, 200649; these regulations have yet to be promulgated. Under the
October 2005 proposal, power plants could modify existing facilities without
triggering NSR, provided that the facility’s “maximum hourly emissions achievable”
after the changes were no greater than the same measure at any point during the past
five years. By focusing on the hourly rate, rather than the previous measure (annual
emissions), the new rule would effectively allow increases in annual emissions any
time a modification led to an increase in the hours of operation of a facility. The
agency’s proposal stated that this change would establish a uniform national
emissions test, in conformance with the Fourth Circuit’s decision in the Duke Energy
case, and it downplayed the significance of the change in light of “substantial
emissions reductions from other CAA [Clean Air Act] requirements that are more
efficient.” But internal EPA documents released by an environmental group indicate
that the proposed rule was strongly opposed by the Air Enforcement Division, whose
Director concluded that it would adversely affect the agency’s NSR enforcement
cases and is largely unenforceable as written.50
47 These changes appeared in the Federal Register on Oct. 27, 2003 (68 FR 61247).
48 State of New York v. EPA, No. 03-1380, 2006 Westlaw 662746 [D.C. Cir., Mar. 17,
2006].
49 70 FR 61081, Oct. 20, 2005. The September 2006 proposal had not yet appeared in the
Federal Register as of this writing, but it is available on the EPA’s website at
[http://www.epa.gov/nsr/documents/dapn_analysis_9-8-06.pdf]. It would limit application
of NSR by allowing plants to consider emissions only from the unit undergoing
modification, rather than the entire plant, in determining whether NSR applies.
50 Memorandum of Adam M. Kushner, Director, Air Enforcement Division, U.S. EPA, to
William Harnett, Director, Information Transfer and Program Integration Division, Office
of Air Quality Planning and Standards, Aug. 25, 2005, p. 1.

CRS-24
Thus, there appears to be a conflict between the EPA’s regulatory actions and
its enforcement stance. While the agency stated in promulgating the equipment
replacement rule that “we do not intend our actions today to create retroactive
applicability for today’s rule,” continued pursuit of the enforcement actions filed
during the Clinton Administration would create a double standard for utilities, with
one set of rules applicable to those utilities unlucky enough to have been cited for
violations prior to promulgation of the new rule, and a different standard applicable
afterward. Despite earlier agency denials that the rule would affect ongoing
investigations, in early November 2003, the EPA’s enforcement chief, J. P. Suarez,
and another EPA official were reported to have indicated that the agency would drop
enforcement actions against 47 facilities that had already received notices of
violation, and would drop investigations of possible violations at an additional 70
power companies. Agency staff who were involved in the enforcement actions note
that the prospect of an NSR rollback caused utilities already charged with violations
to withdraw from settlement negotiations over the pending lawsuits, delaying
emission reductions that could have been achieved in the near future.51 (For
additional information, see CRS Report RS21608, Clean Air and New Source
Review: Defining Routine Maintenance
, and CRS Report RL31757, Clean Air: New
Source Review Policies and Proposals
, both by Larry Parker.)
At Congress’s direction, the National Academy of Sciences began a review of
the NSR program in May 2004. An interim report, released in January 2005, said the
committee had not reached final conclusions, but it also said, “In general, NSR
provides more stringent emission limits for new and modified major sources than
EPA provides in other existing programs” and “It is ... unlikely that Clear Skies
would result in emission limits at individual sources that are tighter than those
achieved when NSR is triggered at the same sources.”52 The final report, issued July
21, 2006, found that
[m]ore than 60% of all coal-fired electricity-generation capacity in the United
States currently lacks the kinds of controls for SO and NO emissions that have
2
x
been required under NSR. Also, the older facilities are more likely than newer
facilities to undergo maintenance, repair, and replacement of key components,
so a substantial portion of emissions from the electricity-generating sector is
potentially affected by the NSR rule changes.53
Nevertheless, the report reached ambivalent conclusions. On the one hand, the report
stated, “It is reasonable to conclude that the implementation of the ERP [the proposed
51 See, for example, “Departing EPA Official Issues Broadside at Administration Air,
Enforcement Programs,” Daily Environment Report, Mar. 1, 2002, p. AA-1. Also, “Second
Former EPA Enforcement Official Raps Bush’s New Source Review Reforms,” Daily
Environment Report
, Oct. 22, 2002, p. A-9.
52 National Research Council of the National Academies, Interim Report of the Committee
on Changes in New Source Review Programs for Stationary Sources of Air Pollutants
(Washington, DC: The National Academies Press, 2005), p. 27.
53 National Research Council of the National Academies, New Source Review for Stationary
Sources of Air Pollutants
(Washington, DC: The National Academies Press, 2006),
Prepublication Copy, p. 3.

CRS-25
Equipment Replacement Provision] could lead to SO and NO emission increases
2
x
in some locations and decreases in others.”54 On the other hand,

the committee concluded overall that, because of a lack of data and the
limitations of current models, it is not possible at this time to quantify with a
reasonable degree of certainty the potential effects of the NSR rule changes on
emissions, human health, energy efficiency, or on other relevant activities at
facilities subject to the revised NSR program.55
Besides the NAS study, on April 21, 2003, the National Academy of Public
Administration released a report commissioned by Congress that made sweeping
recommendations to modify NSR. The study panel recommended that Congress end
the “grandfathering” of major air emission sources by requiring all major sources that
have not obtained an NSR permit since 1977 to install Best Available Control
Technology or Lowest Achievable Emissions Rate control equipment. In the interim,
the NAPA panel concluded, the EPA and the Department of Justice should continue
to enforce NSR vigorously, especially for changes at existing facilities.56
54 Ibid., p. 5.
55 Ibid., p. 2.
56 National Academy of Public Administration, A Breath of Fresh Air: Reviving the New
Source Review Program
, Summary Report, April 2003, p. 3.