United States Court of Appeals, District of Columbia Circuit
December 18, 2018
Petitions for Review of Final Agency Action of the United
States Environmental Protection Agency
L. Johnson argued the cause for Public Health and
Environmental Petitioners. With him on the briefs were Joshua
Stebbins, Joshua Berman, David S. Baron, and Paul Cort.
Dominic E. Draye, Deputy Solicitor General, Office of the
Attorney General for the State of Arizona, argued the cause
for State Petitioners. With him on the briefs were Mark
Brnovich, Attorney General, John R. Lopez, IV, Solicitor
General, Keith Miller, Associate Solicitor, Joshua L. Kaul,
Attorney General, Office of the Attorney General for the
State of Wisconsin, Misha Tseytlin, Solicitor General, Daniel
P. Lennington, Assistant Attorney General, Leslie C.
Rutledge, Attorney General, Office of the Attorney General
for the State of Arkansas, Lee Rudofsky, Solicitor General,
Jamie L. Ewing, Assistant Attorney General, Jeff Landry,
Attorney General, Office of the Attorney General for the
State of Louisiana, Steven B. “Beaux” Jones,
Assistant Attorney General, Wayne Stenehjem, Attorney
General, Office of the Attorney General for the State of
North Dakota, Margaret I. Olson, Assistant Attorney General,
Peter S. Glaser, Carroll W. “Mack” McGuffey, Andy
Beshear, Attorney General, Office of the Attorney General for
the Commonwealth of Kentucky, Joseph A. Newberg, II,
Assistant Attorney General, Lara Katz, Assistant Attorney
General, Office of the Attorney General for the State of New
Mexico, Ken Paxton, Attorney General, Office of the Attorney
General for the State of Texas, Priscilla M. Hubenak, Chief,
Craig J. Pritzlaff, Assistant Attorney General, E. Scott
Pruitt, Attorney General at the time the brief was filed,
Office of the Attorney General for the State of Oklahoma, P.
Clayton Eubanks, Deputy Solicitor General, and Sean Reyes,
Attorney General, Office of the State of Utah. Mithun
Mansinghani, Attorney, Office of the Attorney General for the
State of Oklahoma, Lisa M. Mitchell, Assistant Attorney
General, Office of the Attorney General for the State of
Texas, Oramel H. Skinner, III, Solicitor, Office of the
Attorney General for the State of Arizona, Sarah Adkins and
Samuel R. Flynn, Assistant Attorneys General, and Gregory T.
Dutton, Counsel, Office of the Attorney General for the
Commonwealth of Kentucky, Steven C. Kilpatrick, Assistant
Attorney General, Office of the Attorney General for the
State of Wisconsin, Elizabeth B. Murrill and Harry J.
Vorhoff, Assistant Attorneys General, Office of the Attorney
General for the State of Louisiana, entered appearances.
R. Bieke argued the cause for Industry Petitioners. With him
on the briefs were Roger R. Martella, Joel F. Visser, Scott
C. Oostdyk, E. Duncan Getchell, Jr., Michael H. Brady, Thomas
A. Lorenzen, Robert J. Meyers, Linda E. Kelly, Quentin
Riegel, Leland P. Frost, Michael B. Schon, Elizabeth L.
Horner, Lucinda Minton Langworthy, Aaron M. Flynn, Steven P.
Lehotsky, Sheldon B. Gilbert, Stacy Linden, and Richard S.
Moskowitz. Peter C. Tolsdorf entered an appearance.
M. Babcock and Sarah J. Fox were on the brief for amici
curiae American Thoracic Society, et al. in support of
petitioners Sierra Club, et al.
J. Ward was on the brief for amicus curiae The National
Association of Home Builders in support of Industry and State
Heminger and Simi Bhat, Trial Attorneys, U.S. Department of
Justice, argued the causes for respondent. With them on the
brief were John C. Cruden, Assistant Attorney General at the
time the brief was filed, and David Orlin, Steven Silverman,
and Brian Doster, Attorneys, U.S. Environmental Protection
Agency. Jon M. Lipshultz, Attorney, U.S. Department of
Justice, entered an appearance.
R. Bieke argued the cause for Industry
Respondent-Intervenors. With him on the brief were Roger R.
Martella, Joel F. Visser, Lucinda Minton Langworthy, Aaron M.
Flynn, Thomas A. Lorenzen, Robert J. Meyers, Stacy Linden,
Richard S. Moskowitz, Steven P. Lehotsky, Sheldon B. Gilbert,
Linda E. Kelly, Quentin Riegel, Leland P. Frost, Michael B.
Schon, Elizabeth Horner, and Leslie A. Hulse. Peter C.
Tolsdorf entered an appearance.
L. Johnson argued the cause for Health and Environmental
Respondent-Intervenors. With him on the brief was David S.
Baron. Joshua A. Berman and Joshua R. Stebbins entered
Jonathan Weiner, Deputy Attorney General, Office of the
Attorney General for the State of California, argued the
cause for State Amici in support of respondent. With him on
the brief were Kamala D. Harris, Attorney General at the time
the brief was filed, Robert W. Byrne, Senior Assistant
Attorney General, and Gavin G. McCabe, Supervising Deputy
Attorney General. Melinda Pilling, Attorney, entered an
Richard L. Revesz, Denise A. Grab, Jack Lienke, Michael A.
Livermore, and Jason A. Schwartz were on the brief for amicus
curiae The Institute for Policy Integrity at New York
University School of Law in support of respondent.
Before: Griffith, Pillard and Wilkins, Circuit Judges.
opinion, we consider various challenges to the Environmental
Protection Agency's 2015 revisions to the primary and
secondary national ambient air quality standards for ozone.
For the reasons given below, we deny the petitions, except
with respect to the secondary ozone standard, which we remand
for reconsideration, and grandfathering provision, which we
Statutory and Procedural Background
enacted the modern version of the Clean Air Act (the
"Act"), codified at 42 U.S.C. § 7401 et
seq., in 1970 to control and reduce contaminants
responsible for air pollution with the overarching goal to
protect human health and the environment. Pursuant to Title
I, EPA must establish, publish, and periodically review
primary and secondary national ambient air quality standards
("NAAQS") for air pollutants that "may
reasonably be anticipated to endanger public health or
welfare." 42 U.S.C. § 7408(a)(1)(A). The primary
NAAQS are to be set at levels "the attainment and
maintenance of which in the judgment of the Administrator, .
. . allowing an adequate margin of safety, are requisite to
protect the public health." Id. §
7409(b)(1). The secondary NAAQS "shall specify a level
of air quality the attainment and maintenance of which in the
judgment of the Administrator, . . . is requisite to protect
the public welfare from any known or anticipated adverse
effects." Id. § 7409(b)(2). Thus, primary
NAAQS protect the public health, while the secondary NAAQS
protect the public welfare. "Public health"
includes adverse health effects for both the population at
large and sensitive populations such as children, older
adults, and people with asthma or other lung diseases. The
term "public welfare" encompasses a wide variety of
effects on soil, plants, wildlife and biota, property damage,
aesthetic concerns, and other non-health-related impacts such
as hazards to economic values and personal comfort.
Id. § 7602(h).
to section 109(d) of the Clean Air Act, EPA must complete a
"thorough" review of the NAAQS every five years.
Id. § 7409(d)(1). During this review, EPA must
revise the criteria and standards or promulgate new standards
as appropriate. Id. To assist in this process, the
Clean Air Scientific Advisory Committee ("CASAC")
undertakes an examination of the current air quality
criteria, primary NAAQS, and secondary NAAQS, and submits
recommendations to EPA for "any new [NAAQS] and
revisions of existing criteria and standards as may be
appropriate." Id. § 7409(d)(2)(A)-(B).
Congress required EPA to take CASAC's recommendations
into account when promulgating revised NAAQS and to fully
explain its reasons when it departs from CASAC's advice.
However, the ultimate decision to revise the NAAQS-and the
determination of the new level-rests with the Administrator.
Id. § 7407(d)(3).
petitions concern EPA's promulgation of revised NAAQS
related to ozone. Ozone is a colorless gas that occurs both
in the Earth's upper atmosphere and at ground level.
Although ozone is an "essential presence in the
atmosphere's stratospheric layer," ground-level
ozone is an air pollutant that is harmful to breathe and
damages crops, trees, and other vegetation. S. Coast Air
Quality Mgmt. Dist. v. EPA, 472 F.3d 882, 887 (D.C. Cir.
2006); see Allied Local & Reg'l Mfrs. Caucus v.
EPA, 215 F.3d 61, 66 (D.C. Cir. 2000). Ground-level
ozone is not a direct product of human activity, but instead
forms when atmospheric pollutants (including nitrogen oxides
and volatile organic compounds) react in the presence of
sunlight. See Mississippi v. EPA, 744 F.3d 1334,
1340 (D.C. Cir. 2013). These precursor atmospheric pollutants
are created primarily from emissions produced by cars, power
plants, and chemical solvents. NRDC v. EPA, 777 F.3d
456, 459 (D.C. Cir. 2014).
1979, EPA issued primary and secondary NAAQS for ozone with a
limit of 0.12 parts per millions (ppm), and a one-hour
averaging time. See id. This "one-hour
standard" measured average ozone levels over one-hour
periods, and EPA would deem an area in compliance with this
standard if it did not exceed the level for more than one day
per calendar year. Id. EPA next revised the ozone
NAAQS in 1997, having determined that no revisions to the
standards were necessary in 1993. National Ambient Air
Quality Standards for Ozone, 58 Fed. Reg. 13, 008 (Mar. 9,
1993). The agency replaced the one-hour, 0.12 ppm standard
with a 0.08 ppm standard measured over eight hours. National
Ambient Air Quality Standards for Ozone, 62 Fed. Reg. 38, 856
(July 18, 1997). EPA also altered the form of compliance to
the annual fourth-highest daily maximum 8-hour concentration,
averaged over three years. Id.
2008, EPA lowered the primary and secondary standards to
0.075 ppm but kept the same eight-hour averaging time and
form as in 1997. NRDC, 777 F.3d at 462-63; National
Ambient Air Quality Standards for Ozone, 73 Fed. Reg. 16, 436
(Mar. 27, 2008). In developing the 2008 standards, EPA relied
on scientific evidence showing that ozone causes health
effects at and above 0.08 ppm and examined two new clinical
studies that found negative health effects from ozone at
lower levels. See Mississippi, 744 F.3d at 1340.
While CASAC reviewed this same evidence and recommended a
primary level between 0.06 ppm and 0.07 ppm, EPA departed
from this advice and explained that the scientific data
regarding negative health effects at 0.06 ppm was too limited
and inconclusive to support a standard below 0.075 ppm.
See id. at 1340-41. We upheld EPA's primary
standard on this basis but found that EPA had not adequately
explained its revision of the secondary standard.
Id. at 1359-62. We noted that EPA had not properly
determined what level of air quality was requisite to protect
the public welfare. Id. Accordingly, we remanded for
further explanation and reconsideration of the secondary
the promulgation of the 2008 ozone NAAQS, EPA undertook
another comprehensive review of the ozone standards and
scientific data. EPA consolidated its review on remand of the
2008 secondary standard with its ongoing review for the 2015
ozone NAAQS. After conducting public hearings and receiving
approximately 430, 000 written comments on its proposed
revision of the primary and secondary ozone NAAQS, EPA
published its final 2015 ozone NAAQS on October 26, 2015.
National Ambient Air Quality Standards for Ozone ("2015
Rule"), 80 Fed. Reg. 65, 292 (Oct. 26, 2015). For both
the primary and secondary standards, EPA lowered the level
from 0.075 ppm to 0.07 ppm, while retaining the 2008
indicator (ozone), averaging time (8 hours), and form
(three-year average of the fourth-highest daily maximum
8-hour concentration). See id. at 65, 294, 65, 301,
65, 347, 65, 349-50, 65, 352.
on scientific data and CASAC's recommendation, the
Administrator concluded that the 2008 primary ozone standard
(0.075 ppm) was not at a level requisite to protect public
health while allowing an adequate margin of safety.
Id. at 65, 326, 65, 344, 65, 346. The Administrator
placed significant weight on new clinical studies linking
short-term ozone exposure with respiratory effects, including
lung inflammation. See id. at 65, 302-03, 65, 341,
65, 352, 65, 359. EPA conducted its own exposure study and
found that a revised primary NAAQS standard of 0.07 ppm would
"eliminate the occurrence of two or more exposures of
concern to [ozone] concentrations at and above [0.08
ppm]" and would "virtually eliminate the occurrence
of two or more exposures of concern to [ozone] concentrations
at and above [0.07 ppm], even in the worst-case urban study
area and year evaluated." Id. at 65, 353. The
Administrator additionally found that a level of 0.07 ppm
would "protect the large majority of children in the
urban study areas (i.e., about 96% to more than 99%
of children in individual urban study areas) from
experiencing two or more exposures of concern at or above the
[0.06 ppm] benchmark." Id. at 65, 353, 65,
360-64. EPA also evaluated hundreds of epidemiologic studies
that provided statistically relevant information about a
broader population of individuals who are exposed to
uncontrolled air pollution. See id. at 65, 304, 65,
the Administrator considered CASAC's advice on the new
primary ozone standard. See id. at 65, 346, 65, 361.
In advance of the 2015 Rule, CASAC stated that "there is
clear scientific support for the need to revise the
standard" in place since 2008 and recommended setting
the standard within a range of 0.06 ppm to 0.07 ppm, while
leaving the form, averaging time, and indicator unchanged.
Id. at 65, 322, 65, 361.
also assessed the secondary standard and concluded that the
2008 secondary standard (0.075 ppm) was not requisite to
protect public welfare. Id. at 65, 382, 65, 389-90.
Rather, EPA set the secondary standard at 0.07 ppm and kept
the indicator, averaging time, and form the same.
Id. at 65, 369, 65, 403, 65, 409-10. EPA noted that
more than four hundred new studies examining the interplay
between ozone and public welfare had been developed since the
promulgation of the 2008 ozone NAAQS. Id. at 65,
369. These studies strengthened and expanded the scientific
understanding of ozone's effects on plants. The
Administrator analyzed the causal relationship between ozone
exposure and vegetation effects, examining tree growth
impacts, crop yield loss, and visible leaf injury.
Id. at 65, 370; see id. at 65, 294, 65,
369-70. The Administrator gave "primary
consideration" to tree growth impacts, judging that it
was more difficult to assess the welfare significance of crop
yield loss (given that crops are heavily managed) and visible
leaf injury (citing the "lack of established criteria or
objectives"). Id. at 65, 407.
setting the secondary standard, EPA departed from CASAC's
recommendations as to the form and standard of the secondary
ozone NAAQS. CASAC recommended using a single-year averaging
approach, but EPA opted for a three-year average because
"the public welfare significance of effects associated
with multiple years of critical exposures are potentially
greater than those associated with a single year of such
exposure." Id. at 65, 404. The Administrator
also rejected CASAC's recommendation to use the W126
exposure index, a cumulative, seasonal ozone exposure metric,
as the form of the secondary standard, rather than the same
form as the primary standard (three-year average of the
fourth-highest daily level), finding that the latter form was
adequate to restrict cumulative ozone exposures that are
detrimental to vegetation. Id. at 65, 408.
addition to revising the ozone standards, the 2015 NAAQS also
updated the regulations for the Prevention of Significant
Deterioration ("PSD") permitting program. See
id. at 65, 431-34. Under the PSD program, no
construction on a major emitting facility may be commenced in
an area that has attained the air quality standards for any
criteria pollutant unless "the owner or operator of such
facility demonstrates . . . that emissions from construction
or operation of such facility will not cause, or contribute
to, air pollution in excess of any . . . [NAAQS]." 42
U.S.C. § 7475(a)(3)(B). The permitting authority (either
a state or EPA) must grant or deny a completed
preconstruction permit application under the PSD program
within one year of filing. Id. § 7475(c).
claimed that sections 7475(a)(3)(B) and 7475(c) have the
"potential for conflict," which it was authorized
under Chevron to resolve. EPA Br. 132; see
also 80 Fed. Reg. at 65, 433-34. EPA worried that, for a
limited subset of pending permit applications,
complying with section 7475(a)(3)(B)'s demonstration
requirement for the 2015 NAAQS "could hinder compliance
with the requirement under section (c) to issue a
permit within one year of the completeness
determination." 80 Fed. Reg. at 65, 434. In other words,
EPA was unsure how to handle completed permit applications
where sources would have complied with the NAAQS in existence
at the time the application was filed (the 2008 ozone
standards), but where the NAAQS were revised before the
permit was approved. See id. at 65, 433. EPA
resolved this apparent conflict by implementing a
grandfathering provision for pending permit applications that
satisfy one of two permitting criteria. See id. at
65, 431-34. These two applicable categories include: (1)
permit applications that are deemed complete on or before the
signature date of the final rule revising the ozone NAAQS;
and (2) permit applications "for which the reviewing
authority has first published a public notice of the draft
permit or preliminary determination before the effective date
of the revised NAAQS." Id. at 65, 431, 65, 433.
If a permit application satisfies either requirement, the
owner or operator must show compliance with the 2008 rather
than the 2015 NAAQS before initiating construction.
from the oil and gas industry ("Industry
Petitioners") and from several states ("State
Petitioners") claim that the primary and secondary NAAQS
are too protective. Conversely, petitioners from public
health and environmental groups ("Environmental
Petitioners") claim that these NAAQS are not protective
enough. Environmental Petitioners also contend that EPA's
decision to allow limited grandfathering of certain permit
applications was inconsistent with the Clean Air Act.
opinion proceeds in five parts. Part II considers the
challenges to the primary standard, and Part III the
challenges to the secondary standard. Part IV reviews the
cross-cutting challenges to EPA's promulgation of the
NAAQS, and Part V addresses the challenge to the
Jurisdiction and Standard of Review
court has jurisdiction to review EPA's 2015 Rule pursuant
to 42 U.S.C. § 7607(b)(1). Under section 7607, agency
action may be reversed if it is arbitrary, capricious, an
abuse of discretion, not in accordance with law, or in excess
of statutory authority. Id. § 7607(d)(9)(A),
(C); see Am. Petroleum Inst. v. EPA, 684 F.3d 1342,
1347 (D.C. Cir. 2012). To withstand review, an agency must
have examined all relevant facts and data, and articulated a
rational explanation for its decision, including a reasonable
connection between the facts and ultimate outcome. See
Allied Local, 215 F.3d at 68. We cannot look at
EPA's decision as would a scientist, but instead must
exercise our "narrowly defined duty of holding agencies
to certain minimal standards of rationality."
Mississippi, 744 F.3d at 1342 (quoting Nat'l
Envtl. Dev. Ass'n's Clean Air Project v. EPA,
686 F.3d 803, 810 (D.C. Cir. 2012)); see id. at 1348
("We repeat: it is not our job to referee battles among
experts; ours is only to evaluate the rationality of
EPA's decision . . . .").
questions of statutory interpretation, the court must review
EPA's actions in accordance with the standard set forth
in Chevron, U.S.A., Inc. v. Natural Resources Defense
Council, Inc., 467 U.S. 837, 842-44 (1984). See
Michigan v. EPA, 135 S.Ct. 2699, 2706-07 (2015);
NRDC, 777 F.3d at 463. Chevron deference
involves a two-step analysis. First, if a statute is clear,
the court must give effect to Congress's unambiguous
language and intent. Chevron, 467 U.S. at 842-43.
Where a statute that an agency administers is ambiguous, the
court must turn to the second Chevron principle and
give deference to the agency's reasonable interpretation
of the statute. Id. at 843; see also S. Coast
Air Quality Mgmt. Dist., 472 F.3d at 891.
Primary Standard Challenges
and State Petitioners contend that EPA's promulgation of
the 2015 Rule's primary standard was arbitrary and
capricious because, they say, EPA failed to provide a
reasoned explanation for departing from the 2008 NAAQS.
Environmental Petitioners argue that the primary ozone
standard is too lenient because it occasionally permits ozone
levels to exceed 0.07 ppm and will allegedly tolerate adverse
health effects. For the reasons below, we hold that these
arguments lack merit.
Industry and State Petitioners' Challenge
Clean Air Act requires EPA to set primary NAAQS that are
"requisite" to protect public health with an
adequate margin of safety. 42 U.S.C. § 7409(b)(1). The
term "requisite" means "sufficient, but not
more than necessary." See Whitman v. Am. Trucking
Ass'ns, 531 U.S. 457, 473 (2001). While the
determination of what is "requisite" may require a
contextual assessment of acceptable risk, our precedent is
clear that prior NAAQS are not sacrosanct and are not granted
presumptive validity. See Mississippi, 744 F.3d at
1343. Prior NAAQS need not remain the governing standard
until every aspect of those prior NAAQS is undermined.
Id. To hold otherwise "would bind EPA to
potential deficiencies in past reviews because discrepancies
between past and current judgments as easily reflect problems
in the past as in the present." Id. Thus, when
EPA reviews and revises the NAAQS, it does so against current
policy considerations and existing scientific knowledge.
Id. Accordingly, ...