Ozone and Particulate Air Quality: Should Deadlines for Attainment Be Extended?
CRS Report for Congress
Received through the CRS W eb
Ozone and Particulate Air Quality: Should
Deadlines for Attainment Be Extended?
Specialist i n Environmental Policy
Resources, Science, and Industry Division
Over t h e n ex t year, C ongress and t he Envi ronm ent al P rot ect i o n Agency (EP A) wi l l
consi d er whet her t o m ai nt ai n t he C l ean Ai r A ct ’s st ri ct requi rem ent s for areas t h at have
not attained air quality standards. These “nonattainment” areas, m any o f which will be
so designat ed for t he first time as EPA implements m ore s tringent standards for ozone
a nd fine particles i n 2004, must implement controls on pollution s ource s o r f a c e
sanctions, i ncluding a cutoff o f federal high way funds and requirements t hat n ew
sources offset thei r emissions by reducing emissions at ex isting facilities. In its Clear
Skies b ill (H.R. 999 / S . 485) and i n r e g u l a t o ry guidance, the Administration h as
proposed additional flex i b ility for nonattainment areas, b eyond that prov i d ed i n the
ex i s t i n g C l ean Ai r A ct . W het h er t h e A gency h as ex ceeded i t s aut hori t y b y e x t e n d i ng
deadlines for ex i sting nonattainment areas, and whether t he statutory requ i r ements
should b e m ade m ore flex i ble are questions Congress may consider. This report will
be updated as events warrant.
Despite steady improvements i n air qualit y i n m any of t he United S tates’ most
polluted cities, the goal of clean ai r continues t o elude the nation. Of particular concern
are t h e two m ost wides pread criteria pollutants: ozone and particulat e m atter. On ho t
summer days, high levels of ozo n e (also referred t o as “smog”) can blanket m uch o f
California and the eastern half of the country, causing acute respiratory p roblems for some
people, worsening asthma, and i ncreas ing s usceptibility to respirat ory illnesses, incl uding
bronchitis and pneumonia. Par ticulate m atter, found in many of the s ame areas, causes
respiratory and cardiovascul a r problems, and t housands of premature d eaths annually.1
1 There i s a vast and growi ng literature on the hea lth effects of particulates. For a brief summary
indicati ng s ome dimensions of the estimated pr emature mortality, see St atement of J onathan
Levy, Harvard School of Public Health, a t “ Health Effects of PM-2.5 Emissions , ” Hearing,
Senate Envi ronment a nd Public Works Committee, October 2, 2002. Professor Levy c oncluded
that particulate emi ssions from power plants alone cause 30,000 premature deaths per year in the
United States. More recent r esearch indicates a correlation between particulate concentrations
and i nfant mortality. See “Study Finds Dr op in Infant Mortality Corresponds with Decrease i n
Congressional Research Service ˜ The Library of Congress
Bo th pollutants affect urban, suburban, and rural areas. As o f J une 2003, 53 areas with
and 62 areas with 29 million people had not attained the s tandard for particulat e m atter
(P M). 2
The number o f areas in nonattainment and t he population affected are both ex p ected
to increase i n 2004, as EPA implements m ore s tringent standards for the t wo pollutants.
The C lean Air Act requires t hat t he Agen cy review its ai r quality standards every five
years, and either reaffirm o r m odify them , b ased on the l atest s cience. In 1997, EPA
com p l et ed i t s m o st recent revi ew and prom ul gat ed a st rengt h eni n g o f bot h t he oz one and
P M st andards. Due t o l egal chal l enges and o ther delays , t he new s tandards h ave not yet
been implemented, b u t w h e n they are implemented (now ex pected in 2004), t hey are
likely t o double t he number o f areas in nonattainment.
Nonattainment of National Ambient Air Quality Standards drives m any of t he Clean
Air Act ’s programs. Failure to attain the s tandards s et s i n m otion S tate Im plem entation
P l ans t hat est abl i s h d et ai l ed requi rem ent s f o r s ources of air pollution, including the
imposition o f R easonably Available C ontro l T echnologies o n s tationary sources of
pollutio n ; a requirement that new s ources of pollution i n nonattainment areas “offset”
thei r emissions by reductions in pollution from o ther sources; t he operation o f i nspection
and m ai nt enance program s for aut o em i ssi on controls; requirements t o u se c l eaner
burni n g reformulated gasoline as a means o f reducing emissions; and the n ecessity of
demonstrating t hat new highway and transit project s “co n form” to the S tate
Im plem entation P lan for the area i n which they will be constructed. Any m odification i n
the implementation s chedule for NAAQS, t hus, would affect not only air quality, but also
many of the requirements imposed by the C l ean Air Act on industry and other s tationary
sources of air pollution, car and t ruck owners , and transportation construction project s.
This report e x p l a i n s t he implementation s chedul es requi red b y t he C l ean Ai r A ct ,
descri bes recent s t eps t aken b y E P A t o m odi fy t h e s t at u t o ry requi rem ent s, and d i s cusses
legi slation t hat might alter t he current implementation s tructure. W e begin by discussing
the current standards.
I m pl ementati on of the Cur r e nt NAAQ S
Under t he 1990 Clean Air Act Amendmen ts (P.L. 101-549), o z o n e nonattainment
areas were cl assi fi ed i n one of fi ve cat egori es: Margi n al , M oderat e, S eri ous, S evere, or
Ex trem e. The i nitial classification was determined by the fourth highes t ozone concen-
Particulates,” Daily Environment Report, August 7 , 2003, p. A-3.
2 T he s tandards f or these pollutants, known a s National Ambient Air Quality Standards ( NAAQS)
ar e s et by EPA. T h e Cl ean Ai r Act r e qui r e s t ha t t he Agency set NAAQS at l e ve l s necessar y t o
protect the public health with an adequate margin of safety, based on a r eview of t he scientific
literature. In addition t o t he standards f or ozone and PM, EPA h as set NAAQS for s ulfur dioxide,
nitrogen dioxide, carbon monoxide, a nd lead. F ew e r a r e a s are i n nonattainment of these other
standards. For current information on t he loca tion of nonattainment areas, visit EPA’s website
at [ ht t p: / / www.epa.gov/ oar / oaqps/ gr eenbk/ i ndex.ht ml ] .
Table 1. Ozone Nonattainment Classifications
Cl ass Margi n a l Mod erate S eri ou s S evere E x treme
Deadline 3 years 6 years 9 years 15-17 yrs.* 20 years
1990 42 areas 32 areas 14 areas 9 areas 1 area
2003 20 areas 7 areas 12 areas 12 areas 1 area
Design 0.121 ppm- 0.138 ppm- 0.160 ppm- 0.180 ppm- >0.280 ppm
Valu e 0.138 ppm 0.160 ppm 0.180 ppm 0.280 ppm
* Ar eas with a 1988 design value b etween 0.190 and 0 .280 ppm have 17 years to attain; o thers h a v e 1 5
Numb er of areas in each category as o f the date of enactment.
tration recorded by air quality monitoring e quipment i n t he 3 years p receding p assage of
t h e am endm ent s (a readi n g referred t o as t he area’s “desi gn val u e”). A s s hown i n T abl e
1, areas with high er concentrations of the po llutant (higher des ign val u e s ) were gi ven
more time to reach attainment; i n return for the addit i o n a l time, t hey were required t o
i m p l em e n t m o r e st ri ngent cont rol s on em i ssi ons. Fai l u re t o reach at t ai n m ent by t h e
speci fi ed deadl i n e w as t o resul t i n recl assi fi cat i o n o f an area t o t he nex t hi gh est cat egory
and t he imposition of m ore s tringent controls. Areas cl assified as Serious, for ex am ple,
were required t o reac h a t t a i n ment by 1999. If they did not do so, t he law required t hat
they be reclassified (or “bumped up”) t o S evere, with a n ew deadline o f 2005. Besides
additional time, t h e effect of bumping up the areas would be m ore stringent emission
controls, i ncluding the imposition of controls on smaller s ources of ai r pollution, higher
offset requirements for new s ources of pollu tion, and m andatory use o f cleaner burning
(but more ex pensive) reformulat ed gasoline. (A more detailed ex planation of t he
categories, deadlines, and requirements i s contained i n CRS Report R L30853, Clean Air
Act: A Summary of the Act and Its Major Requirements.)
For a vari et y o f reasons, E P A has general l y not recl assi fi ed areas when t h ey fai l ed
to reach attainment by the s tatutory deadlines. As o f J une 23, 2003 (the latest available
data as this report was written), t he Agency’s website listed 20 M argi n al areas , 7
Moderate areas, and 12 Serious areas,3 many of which would b e categoriz ed as Severe if
the Agency h ad adhered t o t he statutory requirements.
In seven cases,4 the Agency granted additional time to reach attainment on the
grounds that a m ajor cause of the area’s continued nonattainment was pollution generated
outside the area and transported i nto i t by prevailing winds. EPA was s ued over its failure
to bump u p five o f t hese seven areas; o f t he first t hree cases decided (W ashingt on, D.C.,
3 For t he l i s t , s e e [ ht t p : / / www.e p a . go v/ oa r / oa qps / gr e e nbk/ onc .ht ml ] .
4 Metropolitan Washington, DC, St. Louis, Atlant a, Beaumont-Port Arthur (Texas), Baton Rouge,
Gr eater Connecticut, and Western Massachusetts.
St. Louis, and Beaumont-Port Arthur, Tex as), t h e A gency l ost al l t h ree. 5 As a res ult, EPA
has t aken st eps t o recl assi fy t h e t hree areas. It h as al so m oved t o recl assi fy t h e o t h er t w o
areas for which it was s ued (Atlanta and Baton R ouge).
While it might seem reasonable t o give areas ex tra time to attain the standards i f t heir
air quality is substantially affect ed by upwind s ources , t he Clean Air Act m a k e s n o
provision for s uch ex t e n s i ons. Lacking s uch authority, EPA will be under i ncreased
pressure in the future t o bump u p additional areas. In response t o s uch p ressure, at a J u ly
said the Agency would s upport l egislation t o ex t end t he attainment deadlines for areas not
meeting NAAQS because of emissions transported from upwind areas.6 As of August
2003, no such legi slation h ad been introduced, but several m embers, i ncluding the C hair
of the House s ubcommittee of j urisdiction h ave ex p ressed s upport for the concept.7
In t h e m eantime, t he Agency is not without power to deal with transported a i r
pollution. In Section 126, the C lean Air Act provides t hat areas o r states affected by
upwind s ources can petition t he Agency to impose emission limit s and compliance
schedules on such sources . If t he Administrat or determines that upwind facilities
sign ificantly contribute t o l evels o f air pollut i o n i n ex cess o f t he NAAQS in an area
outside the state in which t hey are locat ed, he or she may impose emission limits. Until
recently, t his s ection h ad been little used; i n 2004, however, s ources in 19 states and t he
District of Columbia (mostly el ect ric powerpl an t s ) will become subject to controls on
nitrogen ox ides, i n p art b ecause of petitions filed under S ection 126. 8
I m pl ementati on of the New NAAQ S
A s econd set o f d eadl i n e i ssues concerns i m plemen t ation of t he new s tandards for
oz one and fine p articles t hat EPA promulgated i n 1997. Due t o l egal challenges and o ther
delays , t he new s tandards h ave not yet b een impl em ent ed, but (as not ed earl i er) when t h ey
are implemented (now ex pected in 2004), t hey are likely t o double t he number o f areas
Early Action Compacts. In response t o an i nitiative from t he State o f Tex as, i n
J une 2002, EPA approved a protocol under which new areas can avoid d esignation as
nonattainment for o z one until December 31, 2007, i f they voluntarily commit to
5 T he t hree 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 Ci r. 2002);and Sierra Club v. EPA, 294 F.3d 155,
6 “EPA Would Support Ove rturni ng Courts on Policy Extendi ng Attainme nt Deadlines,” Daily
Environment Report , J uly 23, 2003, p. A-1. Holmstead spoke a t a hearing of t he Energy and Air
Quality Subcommittee of t he House Energy and Commerce Committee.
7 Ib i d .
8 For i nformat i o n, see “ Re gi onal T ransport of Smog ( Ozone) Section 126 Pe titions,” at
[ ht t p: / / www.epa.gov/ ai r l i nks / a i r l i nks 2.ht ml ] . EPA l at er del a ye d i mpl e me nt at i on of t he Sect i on
126 actions to coincide with its NOx SIP Call. See “EPA Will Delay Compliance Deadline f or
Ozone-T ransport Rule, Whitman Says ,” Daily Environment Report, J anuary 18, 2002, p. A-1.
enforceabl e earl y act i o n com pact s w i t h t h ei r s t at e and E P A . T he Earl y A ct i o n p rot o col
sets out a number of milestones t hat areas must meet in o r d e r t o q u a lify.9 Thirty-five
areas met t he first of t hese requirements by s ubmitting s igned compact s t o EPA by
December 31, 2002.10
As with the earlier “bump-up” policy, the early action compact s do not appear to be
authorized by the ex i sting s tatute. In ex plaining its rationale, t he Agency stat es that the
compact s “will offer a more ex peditious timeline for achieving emission reductions than
the E P A ’ s ex pected 8-hour implementation r ulemaking, while providing ‘fail-safe’
provisions for t he area to rever t t o the t raditional S tate Im plem entation P lan process i f
speci fic milestones are not met.”11
W h at ever t h ei r l egal aut hori t y, t he com p act s p rovi de an i n t erest i n g m i x of vol unt ary
and m andat o ry el em ent s , as w el l as a m i x of ex pedited and deferred actions. The decision
to enter i nto a compact is voluntary, but once established, the elements of t he plan must
be incorporat ed in the area’s S tate Im plem entation P lan, making them legally enforceable.
The plan requires earlier planning, implementation, and emission reductions than might
be achieved under t he formal State Implement ation P lanning process, but in return defers
the Act’s formal requirements and pot ential s anctions for almost 4 years.
Clear Skies P roposal
Transitional Areas. The Administration h as also proposed modifications of the
implementation s chedule for nonattainment areas in its Clear Skies b ill (H.R. 999 / S .
485). In S ection 3 , C lear Skies would allow EPA to avoid designating 8-hour oz one and
PM2.5 (fine particle)12 areas as nonattainme n t until 2016, provided t hat t he area
demonstrates that i t w ill attain the s tandards b y December 31, 2015. (EP A is currently
required t o i ssue final design ations of 8-hour oz one nonattai n m e n t areas by April 15,
2004. PM2.5 areas are ex p ect ed t o b e d e s i gn a t ed l at er i n t he sam e year.) The A gency
proposes to create a n ew category for such ar eas, l abeling t hem “transitional.”
Areas fitti ng into the new transitional cat egory could avoid additional regulat ory
cont r o ls, i f t hey could d emonstrate t hat attainment will be achieved t hrough t he
imposition of federal controls on utilities, dies el engi nes, automobiles, and other sources .
The l ogic here is that most such areas will not need to undertake area-specific controls,
but wi l l achi eve at t ai n m ent as t h e resul t o f federal cont rol s t h at have al ready b een
proposed or promulgated, but not yet implemented. The s e federal controls include the
“ NOx SIP call,” which will reduce emissions of nitrogen ox ides from powerpla n t s
9 The protocol i s available on EPA’s website at
[ h t t p : / / www.epa.gov/ttn/naaqs/ozone/ o zonet ech/ 8hr o3pr ot ocol _061902.pdf ] . Additional
information on t he implemen t a t i o n s chedule f or compact areas can be found at
10 A list of t he areas is available on EPA’s website at
11 U.S. EPA, “Protocol f or Early Action Compacts,” previ ously cited, p. 1.
12 Fi ne particles are those with a diameter l ess t han 2.5 mi crometers i n size, generally designated
begi nning in May 2004; the “Tier 2" auto emissions standards, that will reduce emissions
from n ew cars and light trucks more than 90% begi nning in 2004, with full phase-in b y
2009; a 97% reduction o f s ulfur i n d iesel fuel, which t akes effect in 2006; a greater than
90% reduction i n emissions from n ew on - r o a d diesel engi nes, that will be phased i n
between 2007 and 2010; and o ther measures , s ome o f which are not yet final.
Under current law, there i s n o authority for such a t ransi t i onal cat egory. R at h er, E P A
is required t o d esignate nonattainment areas within 2 years o f p romulgating a NAAQS,
and upon design ation s et a d ate b y which each ar ea will achieve attainment. The date may
be 5 years o r 1 0 years following design ation. The 10-year date may also b e ex t ended for
two one-year periods. W ithin 3 years o f t he ir design ation, nonattainment areas must
identify i n a Stat e Implementation P lan t he measures that will achieve attainment. Failure
to identify and implement such meas ures can result in sanctions, i ncluding a cutoff of
federal t ransportation funding and a requi red 2 t o 1 emissions offset for n ew sources of
pollution. Nonattainment areas must al so demonstrate t hat any federally fu n d ed
transportation p rojects will “conform” to the area’s p lan for attaining t he NAAQS .
Nonconforming p rojects are not allowed t o b e funded. Under t he Clear Skies approach,
these requirements would all be delayed for at least 1 2 years.
Section 126. Clear Skies would also limit the use of Section 126 petitions for
control of i nterstat e s ources of ai r pollution. Under S ection 3 of t he bill, there would be
an 8-year prohibition on t he use of S ection 12 6 : n o S e ction 126 requirements could be
imposed prior t o J anuary 1, 2012. W h en the m oratorium i s lifted, the Admi n i s t r ator’s
power to impose s uch requirements would be limited t o t hose cas es in which i t i s
determined that Section 126 controls would b e at l east as cost-effective as any other
emission reduction from a principal cat egory o f em i ssi on sources.
Outlook. In the d ebate over C lear Skies, the p rovisions dealing with nonattainment
areas have been little noticed. The debate’s focus has been on the impact s of t he Clea r
Skies cap and t rade program for powerplant emissions, i ncluding whe t her t hose
provisions strengthen or weaken ex isting l aw, and whether t he bill should i nclude controls
on carbon diox ide emissions. These questions have been sufficiently controversial t hat
few observers ex pect t o see t he bi l l enact ed i n t h e s hort t erm . (For a d i s cussi on of C l ear
Skies, see CRS Issue Brief IB10107, Clean Air Act Issues in the 108 th Congress.)
Still, enactment of Clear Skies i s considered a high priority by the Administration.
And providing additional flex i bility in implementation of t he Clean Air Act has been a
consistent theme under t his and the p revious Administration. Thus, s ome m odification
of the s tatutory provisions for implementation o f t he new o z one and p articulate s tandards,
through regulation o r l egislation, is likely t o remain under consideration.