Order Code RS21611
September 4, 2003
CRS Report for Congress
Received through the CRS Web
Ozone and Particulate Air Quality: Should
Deadlines for Attainment Be Extended?
name r edacted
Specialist in Environmental Policy
Resources, Science, and Industry Division
Over the next year, Congress and the Environmental Protection Agency (EPA) will
consider whether to maintain the Clean Air Act’s strict requirements for areas that have
not attained air quality standards. These “nonattainment” areas, many of which will be
so designated for the first time as EPA implements more stringent standards for ozone
and fine particles in 2004, must implement controls on pollution sources or face
sanctions, including a cutoff of federal highway funds and requirements that new
sources offset their emissions by reducing emissions at existing facilities. In its Clear
Skies bill (H.R. 999 / S. 485) and in regulatory guidance, the Administration has
proposed additional flexibility for nonattainment areas, beyond that provided in the
existing Clean Air Act. Whether the Agency has exceeded its authority by extending
deadlines for existing nonattainment areas, and whether the statutory requirements
should be made more flexible are questions Congress may consider. This report will
be updated as events warrant.
Despite steady improvements in air quality in many of the United States’ most
polluted cities, the goal of clean air continues to elude the nation. Of particular concern
are the two most widespread criteria pollutants: ozone and particulate matter. On hot
summer days, high levels of ozone (also referred to as “smog”) can blanket much of
California and the eastern half of the country, causing acute respiratory problems for some
people, worsening asthma, and increasing susceptibility to respiratory illnesses, including
bronchitis and pneumonia. Particulate matter, found in many of the same areas, causes
respiratory and cardiovascular problems, and thousands of premature deaths annually.1
There is a vast and growing literature on the health effects of particulates. For a brief summary
indicating some dimensions of the estimated premature mortality, see Statement of Jonathan
Levy, Harvard School of Public Health, at “Health Effects of PM-2.5 Emissions,” Hearing,
Senate Environment and Public Works Committee, October 2, 2002. Professor Levy concluded
that particulate emissions from power plants alone cause 30,000 premature deaths per year in the
United States. More recent research indicates a correlation between particulate concentrations
and infant mortality. See “Study Finds Drop in Infant Mortality Corresponds with Decrease in
Congressional Research Service ˜ The Library of Congress
Both pollutants affect urban, suburban, and rural areas. As of June 2003, 53 areas with
114 million people were classified as nonattainment for the ozone air quality standard,
and 62 areas with 29 million people had not attained the standard for particulate matter
The number of areas in nonattainment and the population affected are both expected
to increase in 2004, as EPA implements more stringent standards for the two pollutants.
The Clean Air Act requires that the Agency review its air quality standards every five
years, and either reaffirm or modify them, based on the latest science. In 1997, EPA
completed its most recent review and promulgated a strengthening of both the ozone and
PM standards. Due to legal challenges and other delays, the new standards have not yet
been implemented, but when they are implemented (now expected in 2004), they are
likely to double the number of areas in nonattainment.
Nonattainment of National Ambient Air Quality Standards drives many of the Clean
Air Act’s programs. Failure to attain the standards sets in motion State Implementation
Plans that establish detailed requirements for sources of air pollution, including the
imposition of Reasonably Available Control Technologies on stationary sources of
pollution; a requirement that new sources of pollution in nonattainment areas “offset”
their emissions by reductions in pollution from other sources; the operation of inspection
and maintenance programs for auto emission controls; requirements to use cleaner
burning reformulated gasoline as a means of reducing emissions; and the necessity of
demonstrating that new highway and transit projects “conform” to the State
Implementation Plan for the area in which they will be constructed. Any modification in
the implementation schedule for NAAQS, thus, would affect not only air quality, but also
many of the requirements imposed by the Clean Air Act on industry and other stationary
sources of air pollution, car and truck owners, and transportation construction projects.
This report explains the implementation schedules required by the Clean Air Act,
describes recent steps taken by EPA to modify the statutory requirements, and discusses
legislation that might alter the current implementation structure. We begin by discussing
the current standards.
Implementation of the Current NAAQS
Under the 1990 Clean Air Act Amendments (P.L. 101-549), ozone nonattainment
areas were classified in one of five categories: Marginal, Moderate, Serious, Severe, or
Extreme. The initial classification was determined by the fourth highest ozone concen-
Particulates,” Daily Environment Report, August 7, 2003, p. A-3.
The standards for these pollutants, known as National Ambient Air Quality Standards (NAAQS)
are set by EPA. The Clean Air Act requires that the Agency set NAAQS at levels necessary to
protect the public health with an adequate margin of safety, based on a review of the scientific
literature. In addition to the standards for ozone and PM, EPA has set NAAQS for sulfur dioxide,
nitrogen dioxide, carbon monoxide, and lead. Fewer areas are in nonattainment of these other
standards. For current information on the location of nonattainment areas, visit EPA’s website
Table 1. Ozone Nonattainment Classifications
0.121 ppm0.138 ppm
0.138 ppm0.160 ppm
0.160 ppm0.180 ppm
0.180 ppm0.280 ppm
Areas with a 1988 design value between 0.190 and 0.280 ppm have 17 years to attain; others have 15
Number of areas in each category as of the date of enactment.
tration recorded by air quality monitoring equipment in the 3 years preceding passage of
the amendments (a reading referred to as the area’s “design value”). As shown in Table
1, areas with higher concentrations of the pollutant (higher design values) were given
more time to reach attainment; in return for the additional time, they were required to
implement more stringent controls on emissions. Failure to reach attainment by the
specified deadline was to result in reclassification of an area to the next highest category
and the imposition of more stringent controls. Areas classified as Serious, for example,
were required to reach attainment by 1999. If they did not do so, the law required that
they be reclassified (or “bumped up”) to Severe, with a new deadline of 2005. Besides
additional time, the effect of bumping up the areas would be more stringent emission
controls, including the imposition of controls on smaller sources of air pollution, higher
offset requirements for new sources of pollution, and mandatory use of cleaner burning
(but more expensive) reformulated gasoline. (A more detailed explanation of the
categories, deadlines, and requirements is contained in CRS Report RL30853, Clean Air
Act: A Summary of the Act and Its Major Requirements.)
For a variety of reasons, EPA has generally not reclassified areas when they failed
to reach attainment by the statutory deadlines. As of June 23, 2003 (the latest available
data as this report was written), the Agency’s website listed 20 Marginal areas, 7
Moderate areas, and 12 Serious areas,3 many of which would be categorized as Severe if
the Agency had adhered to the statutory requirements.
In seven cases,4 the Agency granted additional time to reach attainment on the
grounds that a major cause of the area’s continued nonattainment was pollution generated
outside the area and transported into it by prevailing winds. EPA was sued over its failure
to bump up five of these seven areas; of the first three cases decided (Washington, D.C.,
For the list, see [http://www.epa.gov/oar/oaqps/greenbk/onc.html].
Metropolitan Washington, DC, St. Louis, Atlanta, Beaumont-Port Arthur (Texas), Baton Rouge,
Greater Connecticut, and Western Massachusetts.
St. Louis, and Beaumont-Port Arthur, Texas), the Agency lost all three.5 As a result, EPA
has taken steps to reclassify the three areas. It has also moved to reclassify the other two
areas for which it was sued (Atlanta and Baton Rouge).
While it might seem reasonable to give areas extra time to attain the standards if their
air quality is substantially affected by upwind sources, the Clean Air Act makes no
provision for such extensions. Lacking such authority, EPA will be under increased
pressure in the future to bump up additional areas. In response to such pressure, at a July
22, 2003 hearing, EPA Assistant Administrator for Air and Radiation, Jeffrey Holmstead,
said the Agency would support legislation to extend the attainment deadlines for areas not
meeting NAAQS because of emissions transported from upwind areas.6 As of August
2003, no such legislation had been introduced, but several members, including the Chair
of the House subcommittee of jurisdiction have expressed support for the concept.7
In the meantime, the Agency is not without power to deal with transported air
pollution. In Section 126, the Clean Air Act provides that areas or states affected by
upwind sources can petition the Agency to impose emission limits and compliance
schedules on such sources. If the Administrator determines that upwind facilities
significantly contribute to levels of air pollution in excess of the NAAQS in an area
outside the state in which they are located, he or she may impose emission limits. Until
recently, this section had been little used; in 2004, however, sources in 19 states and the
District of Columbia (mostly electric powerplants) will become subject to controls on
nitrogen oxides, in part because of petitions filed under Section 126.8
Implementation of the New NAAQS
A second set of deadline issues concerns implementation of the new standards for
ozone and fine particles that EPA promulgated in 1997. Due to legal challenges and other
delays, the new standards have not yet been implemented, but (as noted earlier) when they
are implemented (now expected in 2004), they are likely to double the number of areas
Early Action Compacts. In response to an initiative from the State of Texas, in
June 2002, EPA approved a protocol under which new areas can avoid designation as
nonattainment for ozone until December 31, 2007, if they voluntarily commit to
The three cases were Sierra Club v. EPA, 311 F.3d 853, 55 ERC 1385 (7th Cir. 2002); Sierra
Club v. EPA, 314 F.3d 735, 55 ERC 1577 (5th Cir. 2002);and Sierra Club v. EPA, 294 F.3d 155,
54 ERC 1641 (D.C. Cir. 2002).
“EPA Would Support Overturning Courts on Policy Extending Attainment Deadlines,” Daily
Environment Report, July 23, 2003, p. A-1. Holmstead spoke at a hearing of the Energy and Air
Quality Subcommittee of the House Energy and Commerce Committee.
For information, see “Regional Transport of Smog (Ozone) Section 126 Petitions,” at
[http://www.epa.gov/airlinks/airlinks2.html]. EPA later delayed implementation of the Section
126 actions to coincide with its NOx SIP Call. See “EPA Will Delay Compliance Deadline for
Ozone-Transport Rule, Whitman Says,” Daily Environment Report, January 18, 2002, p. A-1.
enforceable early action compacts with their state and EPA. The Early Action protocol
sets out a number of milestones that areas must meet in order to qualify.9 Thirty-five
areas met the first of these requirements by submitting signed compacts to EPA by
December 31, 2002.10
As with the earlier “bump-up” policy, the early action compacts do not appear to be
authorized by the existing statute. In explaining its rationale, the Agency states that the
compacts “will offer a more expeditious timeline for achieving emission reductions than
the EPA’s expected 8-hour implementation rulemaking, while providing ‘fail-safe’
provisions for the area to revert to the traditional State Implementation Plan process if
specific milestones are not met.”11
Whatever their legal authority, the compacts provide an interesting mix of voluntary
and mandatory elements, as well as a mix of expedited and deferred actions. The decision
to enter into a compact is voluntary, but once established, the elements of the plan must
be incorporated in the area’s State Implementation Plan, making them legally enforceable.
The plan requires earlier planning, implementation, and emission reductions than might
be achieved under the formal State Implementation Planning process, but in return defers
the Act’s formal requirements and potential sanctions for almost 4 years.
Clear Skies Proposal
Transitional Areas. The Administration has also proposed modifications of the
implementation schedule for nonattainment areas in its Clear Skies bill (H.R. 999 / S.
485). In Section 3, Clear Skies would allow EPA to avoid designating 8-hour ozone and
PM2.5 (fine particle)12 areas as nonattainment until 2016, provided that the area
demonstrates that it will attain the standards by December 31, 2015. (EPA is currently
required to issue final designations of 8-hour ozone nonattainment areas by April 15,
2004. PM2.5 areas are expected to be designated later in the same year.) The Agency
proposes to create a new category for such areas, labeling them “transitional.”
Areas fitting into the new transitional category could avoid additional regulatory
controls, if they could demonstrate that attainment will be achieved through the
imposition of federal controls on utilities, diesel engines, automobiles, and other sources.
The logic here is that most such areas will not need to undertake area-specific controls,
but will achieve attainment as the result of federal controls that have already been
proposed or promulgated, but not yet implemented. These federal controls include the
“NOx SIP call,” which will reduce emissions of nitrogen oxides from powerplants
The protocol is available on EPA’s website at
information on the implementation schedule for compact areas can be found at
A list of the areas is available on EPA’s website at
U.S. EPA, “Protocol for Early Action Compacts,” previously cited, p. 1.
Fine particles are those with a diameter less than 2.5 micrometers in size, generally designated
beginning in May 2004; the “Tier 2" auto emissions standards, that will reduce emissions
from new cars and light trucks more than 90% beginning in 2004, with full phase-in by
2009; a 97% reduction of sulfur in diesel fuel, which takes effect in 2006; a greater than
90% reduction in emissions from new on-road diesel engines, that will be phased in
between 2007 and 2010; and other measures, some of which are not yet final.
Under current law, there is no authority for such a transitional category. Rather, EPA
is required to designate nonattainment areas within 2 years of promulgating a NAAQS,
and upon designation set a date by which each area will achieve attainment. The date may
be 5 years or 10 years following designation. The 10-year date may also be extended for
two one-year periods. Within 3 years of their designation, nonattainment areas must
identify in a State Implementation Plan the measures that will achieve attainment. Failure
to identify and implement such measures can result in sanctions, including a cutoff of
federal transportation funding and a required 2 to 1 emissions offset for new sources of
pollution. Nonattainment areas must also demonstrate that any federally funded
transportation projects will “conform” to the area’s plan for attaining the NAAQS.
Nonconforming projects are not allowed to be funded. Under the Clear Skies approach,
these requirements would all be delayed for at least 12 years.
Section 126. Clear Skies would also limit the use of Section 126 petitions for
control of interstate sources of air pollution. Under Section 3 of the bill, there would be
an 8-year prohibition on the use of Section 126: no Section 126 requirements could be
imposed prior to January 1, 2012. When the moratorium is lifted, the Administrator’s
power to impose such requirements would be limited to those cases in which it is
determined that Section 126 controls would be at least as cost-effective as any other
emission reduction from a principal category of emission sources.
Outlook. In the debate over Clear Skies, the provisions dealing with nonattainment
areas have been little noticed. The debate’s focus has been on the impacts of the Clear
Skies cap and trade program for powerplant emissions, including whether those
provisions strengthen or weaken existing law, and whether the bill should include controls
on carbon dioxide emissions. These questions have been sufficiently controversial that
few observers expect to see the bill enacted in the short term. (For a discussion of Clear
Skies, see CRS Issue Brief IB10107, Clean Air Act Issues in the 108th Congress.)
Still, enactment of Clear Skies is considered a high priority by the Administration.
And providing additional flexibility in implementation of the Clean Air Act has been a
consistent theme under this and the previous Administration. Thus, some modification
of the statutory provisions for implementation of the new ozone and particulate standards,
through regulation or legislation, is likely to remain under consideration.
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