Alaska Dept. of Environmental Conservation v. EPA

OPINION OF THE COURT ALASKA DEPT. OF ENVIRONMENTALCONSERVATION V. EPA 540 U. S. ____ (2004) SUPREME COURT OF THE UNITED STATES NO. 02-658 ALASKA DEPARTMENT OF ENVIRONMENTAL CONSERVATION,
PETITIONER v. ENVIRON- MENTAL PROTECTION AGENCY
et al.

															on writ of certiorari to the united states court of
appeals for the ninth circuit

															[January 21, 2004]

															   Justice Ginsburg delivered the
opinion of the Court.

															   This case concerns the authority
of the Environmental Protection Agency (EPA or Agency) to enforce
the provisions of the Clean Air Act’s (CAA or Act) Prevention
of Significant Deterioration (PSD) program. Under that program, no
major air pollutant emitting facility may be constructed unless the
facility is equipped with “the best available control
technology” (BACT). As added by §165, 91 Stat. 735, and
amended, 42 U. S. C. §7475(a)(4). BACT, as defined in the
CAA, means, for any major air pollutant emitting facility,
“an emission limitation based on the maximum degree of
[pollutant] reduction … which the permitting authority, on a
case-by-case basis, taking into account energy, environmental, and
economic impacts and other costs, determines is achievable for
[the] facility… .” §7479(3).

															   Regarding EPA oversight, the Act includes a
general instruction and one geared specifically to the PSD program.
The general prescription, §113(a)(5) of the Act, authorizes
EPA, when it finds that a State is not complying with a CAA
requirement governing construction of a pollutant source, to issue
an order prohibiting construction, to prescribe an administrative
penalty, or to commence a civil action for injunctive relief. 42 U.
S. C. §7413(a). Directed specifically to the PSD program,
CAA §167 instructs EPA to “take such measures, including
issuance of an order, or seeking injunctive relief, as necessary to
prevent the construction” of a major pollutant emitting
facility that does not conform to the PSD requirements of the Act.
42 U. S. C. §7477.

															   In the case before us, “the permitting
authority” under §7479(3) is the State of Alaska, acting
through Alaska’s Department of Environmental Conservation
(ADEC). The question presented is what role EPA has with respect to
ADEC’s BACT determinations. Specifically, may EPA act to
block construction of a new major pollutant emitting facility
permitted by ADEC when EPA finds ADEC’s BACT determination
unreasonable in light of the guides §7479(3) prescribes? We
hold that the Act confers that checking authority on EPA.

															I

															A

															   Congress enacted the Clean Air
Amendments of 1970, 84 Stat. 1676, 42 U. S. C. §7401 et seq. , in response to “dissatisfaction with the
progress of existing air pollution programs.” Union Elec.
Co. v. EPA, 427 U. S. 246 , 249
(1976). The amendments aimed “to guarantee the prompt
attainment and maintenance of specified air quality
standards.” Ibid.; D. Currie, Air Pollution
§1.13, p. 1–16 (1981) (summary of 1970 amendments).
Added by the 1970 amendments, §§108(a) and 109(a) of the
Act require EPA to publish lists of emissions that “cause or
contribute to air pollution which may reasonably be anticipated to
endanger public health or welfare,” and to promulgate primary
and secondary national ambient air quality standards (NAAQS) for
such pollutants. 42 U. S. C. §§7408(a) and 7409(a); Whitman v. American Trucking Assns., Inc., 531 U. S. 457 ,
462–463 (2001). NAAQS “define [the] levels of air
quality that must be achieved to protect public health and
welfare.” R. Belden, Clean Air Act 6 (2001). The Agency
published initial NAAQS in 1971, Union Elec., 427 U. S.,
at 251 (citing 40 CFR pt. 50 (1975)), and in 1985, NAAQS for the
pollutant at issue in this case, nitrogen dioxide. 40 CFR
§50.11 (2002).[ Footnote
1 ]

															   Under §110 of the Act, also
added in 1970, each State must submit for EPA approval “a
plan which provides for implementation, maintenance, and
enforcement of [NAAQS].” 42 U. S. C. §7410(a)(1);
cf. §7410(c)(1) (EPA shall promulgate an implementation plan
if the State’s plan is inadequate). Relevant to this case,
EPA has approved Alaska’s implementation plan. 48 Fed. Reg.
30626 (1983), as amended, 56 Fed. Reg. 19288 (1991); 40 CFR
§52.96(a) (2002). To gain EPA approval, a “state
implementation plan” (SIP) must “include enforceable
emission limitations and other control measures, means, or
techniques … as may be necessary or appropriate to meet the
applicable [CAA] requirements.” 42 U. S. C.
§7410(a)(2)(A). While States have “wide
discretion” in formulating their plans, Union Elec. ,
427 U. S., at 250, SIPs must include certain measures Congress
specified “to assure that national ambient air quality
standards are achieved,” 42 U. S. C.
§7410(a)(2)(C). Among those measures are permit provisions,
§7475, basic to the administration of the program involved in
this case, CAA’s “Prevention of Significant
Deterioration of Air Quality” (PSD) program.

															   The PSD requirements, enacted as part of 1977
amendments to the Act, Title I, §160 et seq. , 91
Stat. 731, “are designed to ensure that the air quality in
attainment areas or areas that are already ‘clean’ will
not degrade,” Belden, supra , p. 43. See 42 U.
S. C. §7470(1) (purpose of PSD program is to
“protect public health and welfare from any actual or
potential adverse effect which in [EPA’s] judgment may
reasonably be anticipate[d] to occur from air pollution …
notwithstanding attainment and maintenance of all national ambient
air quality standards”). Before 1977, no CAA provision
specifically addressed potential air quality deterioration in areas
where pollutant levels were lower than the NAAQS. Alabama Power
Co. v. Costle , 636 F. 2d 323, 346–347
(CADC 1979). Responding to litigation initiated by an environmental
group,[ Footnote 2 ] however, EPA
issued regulations in 1974 requiring that SIPs include a PSD
program. Id. , at 347, and n. 18 (citing 39 Fed. Reg.
42510 (1974)). Three years later, Congress adopted the current PSD
program. See S. Rep. No. 95–127, p. 11 (1977)
(Congress itself has “a responsibility to delineate a policy
for protecting clean air”).

															   The PSD program imposes on States a regime
governing areas “designated pursuant to [42 U. S. C.
§7407] as attainment or unclassifiable.”
§7471.[ Footnote 3 ] An
attainment area is one in which the air “meets the national
primary or secondary ambient air quality standard for [a regulated
pollutant].” §7407(d)(1)(A)(ii). Air in an
unclassifiable area “cannot be classified on the basis of
available information as meeting or not meeting the national
primary or secondary ambient air quality standard for the
pollutant.” §7407(d)(1)(A)(iii). Northwest Alaska, the
region this case concerns, is classified as an attainment or
unclassifiable area for nitrogen dioxide, 40 CFR §81.302
(2002), therefore, the PSD program applies to emissions of that
pollutant in the region. In 2002, the Agency reported that
“[a]ll areas of the country that once violated the NAAQS for
[nitrogen dioxide] now meet that standard.” EPA, Latest
Findings on National Air Quality 7 (Aug. 2003).

															   Section 165 of the Act, 42 U. S. C.
§7475, installs a permitting requirement for any “major
emitting facility,” defined to include any source emitting
more than 250 tons of nitrogen oxides per year, §7479(1). No
such facility may be constructed or modified unless a permit
prescribing emission limitations has been issued for the facility.
§7475(a)(1); see §7479(2)(C) (defining
“construction” to include “modification”).
Alaska’s SIP imposes an analogous requirement. 18 Alaska
Admin. Code §50.300(c)(1) (2003). Modifications to major
emitting facilities that increase nitrogen oxide emissions in
excess of 40 tons per year require a PSD permit. 40 CFR
§51.166(b)(23)(i) (2002); 18 Alaska Admin. Code
§50.300(h)(3)(B)(ii) (2003).

															   The Act sets out preconditions for the
issuance of PSD permits. Inter alia , no PSD permit may
issue unless “the proposed facility is subject to the best
available control technology for each pollutant subject to [CAA]
regulation … emitted from … [the] facility.” 42
U. S. C. §7475(a)(4). As described in the Act’s
definitional provisions, “best available control
technology” (BACT) means:

															“[A]n emission limitation based on the
maximum degree of reduction of each pollutant subject to regulation
under this chapter emitted from or which results from any major
emitting facility, which the permitting authority, on a
case-by-case basis, taking into account energy, environmental, and
economic impacts and other costs, determines is achievable for such
facility through application of production processes and available
methods, systems, and techniques … . In no event shall
application of ‘best available control technology’
result in emissions of any pollutants which will exceed the
emissions allowed by any applicable standard established pursuant
to section 7411 or 7412 of this title [emission standards for new
and existing stationary sources].” §7479(3).

															40 CFR §51.166(b)(12) (2002) (repeating
statutory definition). Alaska’s SIP contains provisions that
track the statutory BACT requirement and definition. 18 Alaska
Admin. Code §§50.310(d)(3) and 50.990(13) (2003). The
State, with slightly variant terminology, defines BACT as
“the emission limitation that represents the maximum
reduction achievable for each regulated air contaminant, taking
into account energy, environmental and economic impacts, and other
costs.” Ibid. Under the federal Act, a limited class
of sources must gain advance EPA approval for the BACT prescribed
in the permit. 42 U. S. C. §7475(a)(8).

															   CAA also provides that a PSD permit may issue
only if a source “will not cause, or contribute to, air
pollution in excess of any … maximum allowable increase or
maximum allowable concentration for any pollutant” or any
NAAQS. §7475(a)(3). Congress left to the Agency the
determination of most maximum allowable increases, or
“increments,” in pollutants. EPA regulations have
defined increments for nitrogen oxides. 40 CFR §51.166(c)
(2002). Typically, to demonstrate that increments will not be
exceeded, applicants use mathematical models of pollutant plumes,
their behavior, and their dispersion. Westbrook, Air Dispersion
Models: Tools to Assess Impacts from Pollution Sources, 13 Natural
Resources & Env. 546, 547–548 (1999).

															   Among measures EPA may take to ensure
compliance with the PSD program, two have special relevance here.
The first prescription, §113(a)(5) of the Act, provides that
“[w]henever, on the basis of any available information, [EPA]
finds that a State is not acting in compliance with any requirement
or prohibition of the chapter relating to the construction of new
sources or the modification of existing sources,” EPA may
“issue an order prohibiting the construction or modification
of any major stationary source in any area to which such
requirement applies.” 42 U. S. C.
§7413(a)(5)(A).[ Footnote
4 ] The second measure, §167 of the Act, trains on
enforcement of the PSD program; it requires EPA to “take such
measures, including issuance of an order, or seeking injunctive
relief, as necessary to prevent the construction or modification of
a major emitting facility which does not conform to the [PSD]
requirements.” §7477.

															B

															   Teck Cominco Alaska, Inc.
(Cominco), operates a zinc concentrate mine, the Red Dog Mine, in
northwest Alaska approximately 100 miles north of the Arctic Circle
and close to the native Alaskan villages of Kivalina and Noatak.
App. to Pet. for Cert. 3a; Brief for Petitioner 8; Brief for
Respondents 4. The mine is the region’s largest private
employer. Brief for Petitioner 9. It supplies a quarter of the
area’s wage base. Ibid. Cominco leases the land from
the NANA Regional Corporation, an Alaskan corporation formed
pursuant to the Alaska Native Claims Settlement Act, 85 Stat. 688,
as amended, 43 U. S. C. §1601 et seq. Brief for
NANA Regional Corporation, Inc., as Amicus Curiae 1–2, 4.

															   In 1988, Cominco obtained
authorization to operate the mine, a “major emitting
facility” under the Act and Alaska’s SIP. App. 106. The
mine’s PSD permit authorized five 5,000 kilowatt Wartsila
diesel electric generators, MG–1 through MG–5, subject
to operating restrictions; two of the five generators were
permitted to operate only in standby status. Ibid. Petitioner Alaska Department of Environmental Conservation (ADEC)
issued a second PSD permit in 1994 allowing addition of a sixth
full-time generator (MG–6), removing standby status from
MG–2, and imposing a new operational cap that allowed all but
one generator to run full time. Ibid. In 1996, Cominco initiated a project, with
funding from the State, to expand zinc production by 40%. Brief for
Petitioner 5; Reply Brief for Petitioner 11, n. 9.
Anticipating that the project would increase nitrogen oxide
emissions by more than 40 tons per year, see supra , at 5,
Cominco applied to ADEC for a PSD permit to allow, inter
alia , increased electricity generation by its standby
generator, MG–5. App. 107–108; App. to Pet. for Cert.
33a. On March 3, 1999, ADEC preliminarily proposed as BACT for
MG–5 the emission control technology known as selective
catalytic reduction (SCR),[ Footnote
5 ] which reduces nitrogen oxide emissions by 90%. App. 72, 108.
In response, Cominco amended its application to add a seventh
generator, MG–17, and to propose as BACT an alternative
control technology—Low NOx[ Footnote 6 ]—that achieves a 30% reduction in
nitrogen oxide pollutants. Brief for Respondents 5, and n. 1;
App. 84.

															   On May 4, 1999, ADEC, in conjunction with
Cominco’s representative, issued a first draft PSD permit and
preliminary technical analysis report that concluded Low NOx was
BACT for MG–5 and MG–17. Id., at 55–95.
To determine BACT, ADEC employed EPA’s recommended top-down
methodology, id. , at 61:

															“In brief, the top-down process provides that
all available control technologies be ranked in descending order of
control effectiveness. The PSD applicant first examines the most
stringent—or ‘top’—alternative. That
alternative is established as BACT unless the applicant
demonstrates, and the permitting authority in its informed judgment
agrees, that technical considerations, or energy, environmental, or
economic impacts justify a conclusion that the most stringent
technology is not ‘achievable’ in that case. If the
most stringent technology is eliminated in this fashion, then the
next most stringent alternative is considered, and so on.”
EPA, New Source Review Workshop Manual B2 (Draft Oct. 1990)
(hereinafter New Source Review Manual); App. 61–62.[ Footnote 7 ]

															   Applying top-down methodology,
ADEC first homed in on SCR as BACT for MG–5, and the new
generator, MG– 17. “[W]ith an estimated reduction of
90%,” ADEC stated, SCR “is the most stringent”
technology. Id., at 79. Finding SCR “technically and
economically feasible,” id. , at 65, ADEC
characterized as “overstated” Cominco’s cost
estimate of $5,643 per ton of nitrogen oxide removed by SCR. Id. , at 113. Using Cominco’s data, ADEC reached a
cost estimate running between $1,586 and $2,279 per ton. Id. , at 83. Costs in that range, ADEC observed, “are
well within what ADEC and EPA conside[r] economically
feasible.” Id. , at 84. Responding to Cominco’s
comments on the preliminary permit, engineering staff in
ADEC’s Air Permits Program pointed out that, according to
information Cominco provided to ADEC, “SCR has been installed
on similar diesel-fired engines throughout the world.” Id. , at 102.

															   Despite its staff’s clear view
“that SCR (the most effective individual technology) [was]
technologically, environmentally, and economically feasible for the
Red Dog power plant engines,” id. , at 103–104,
ADEC endorsed the alternative proffered by Cominco. To achieve
nitrogen oxide emission reductions commensurate with SCR’s
90% impact, Cominco proposed fitting the new generator MG–17
and the six existing generators with Low NOx. Ibid.[ Footnote 8 ] Cominco asserted that
it could lower net emissions by 396 tons per year if it fitted all
seven generators with Low NOx rather than fitting two (MG–5
and MG–17) with SCR and choosing one of them as the standby
unit. Id., at 87. Cominco’s proposal hinged on the
“assumption … that under typical operating conditions
one or more engines will not be running due to maintenance of
standby-generation capacity.” Ibid. If all seven
generators ran continuously, however, Cominco’s alternative
would increase emissions by 79 tons per year. Ibid. Accepting Cominco’s submission, ADEC stated that
Cominco’s Low NOx solution “achieve[d] a similar
maximum NOx reduction as the most stringent controls; [could]
potentially result in a greater NOx reduction; and is logistically
and economically less onerous to Cominco.” Id. , at
87–88.

															   On the final day of the public comment period,
July 2, 1999, the United States Department of the Interior,
National Parks Service (NPS), submitted comments to ADEC. App. to
Pet. for Cert. 33a; App. 97, 108. NPS objected to the projected
offset of new emissions from MG–5 and MG–17 against
emissions from other existing generators that were not subject to
BACT. Letter from John Notar, NPS Air Resources Division, to Jim
Baumgartner, ADEC (June 2, 1999). Such an offset, NPS commented,
“is neither allowed by BACT, nor achieves the degree of
reduction that would result if all the generators that are subject
to BACT were equipped with SCR.” Id. , at 3. NPS
further observed that the proposed production-increase project
would remove operating restrictions that the 1994 PSD permit had
placed on four of the existing generators—MG–1,
MG–3, MG–4, and MG–5. App. to Pet. for Cert. 34a.
Due to that alteration, NPS urged, those generators, too, became
part of the production-expansion project and would be subject to
the BACT requirement. Ibid. Following NPS’ lead, EPA wrote to ADEC
on July 29, 1999, commenting: “Although ADEC states in its
analysis that [SCR], the most stringent level of control, is
economically and technologically feasible, ADEC did not propose to
require SCR… . [O]nce it is determined that an emission
unit is subject to BACT, the PSD program does not allow the
imposition of a limit that is less stringent than BACT.” App.
96–97. A permitting authority, EPA agreed with NPS, could not
offset new emissions “by imposing new controls on other
emission units” that were not subject to BACT. Id. ,
at 97. New emissions could be offset only against reduced emissions
from sources covered by the same BACT authorization. Id. ,
at 285–286. EPA further agreed with NPS that, based on the
existing information, BACT would be required for MG–1,
MG–3, MG–4, and MG–5. Id. , at 97.

															   After receiving EPA comments, ADEC issued a
second draft PSD permit and technical analysis report on September
1, 1999, again finding Low NOx to be BACT for MG–17. Id., at 105–117. Abandoning the emissions-offsetting
justification advanced in the May 4 draft permit, ADEC agreed with
NPS and EPA that “emission reductions from sources that were
not part of the permit action,” here MG–1, MG–2,
MG–3, MG–4, MG–5, and MG–6, could not be
considered in determining BACT for MG–17. Id. , at
111; id. , at 199 (same).[ Footnote 9 ]

															   ADEC conceded that, lacking data from Cominco,
it had made “no judgment … as to the impact of
… [SCR] on the operation, profitability, and competitiveness
of the Red Dog Mine.” Id. , at 116. Contradicting its
May 1999 conclusion that SCR was “technically and
economically feasible,” see supra, at 10, ADEC found
in September 1999 that SCR imposed “a disproportionate
cost” on the mine. App. 116. ADEC concluded, on a
“cursory review,” that requiring SCR for a rural Alaska
utility would lead to a 20% price increase, and that in comparison
with other BACT technologies, SCR came at a “significantly
higher” cost. Ibid. No economic basis for a
comparison between the mine and a rural utility appeared in
ADEC’s technical analysis.

															   EPA protested the revised permit. In a
September 15, 1999, letter, the Agency stated: “Cominco has
not adequately demonstrated any site-specific factors to support
their claim that the installation of [SCR] is economically
infeasible at the Red Dog Mine. Therefore, elimination of SCR as
BACT based on cost-effectiveness grounds is not supported by the
record and is clearly erroneous.” Id. , at 127; see id. , at 138 (ADEC’s record does not support the
departure from ADEC’s initial view that the costs for SCR
were economically feasible).

															   To justify the September 1, 1999, permit, EPA
suggested, ADEC could “include an analysis of whether
requiring Cominco to install and operate [SCR] would have any
adverse economic impacts upon Cominco specifically.” Id. , at 127. Stating that such an inquiry was unnecessary
and expressing “concerns related to confidentiality,”
Cominco declined to submit financial data. Id. , at 134. In
this regard, Cominco simply asserted, without detail, that the
company’s “overall debt remains quite high”
despite continuing profits. Id. , at 134–135. Cominco
also invoked the need for “[i]ndustrial development in rural
Alaska.” Id. , at 135.

															   On December 10, 1999, ADEC issued the final
permit and technical analysis report. Once again, ADEC approved Low
NOx as BACT for MG–17 “[t]o support Cominco’s Red
Dog Mine Production Rate Increase Project, and its contributions to
the region.” Id. , at 208. ADEC did not include the
economic analysis EPA had suggested. Id. , at
152–246. Indeed, ADEC conceded again that it had made
“no judgment … as to the impact of …
[SCR’s] cost on the operation, profitability, and
competitiveness of the Red Dog Mine.” Id. , at 207.
Nonetheless, ADEC advanced, as cause for its decision, SCR’s
adverse effect on the mine’s “unique and continuing
impact on the economic diversity of th[e] region” and on the
venture’s “world competitiveness.” Id. ,
at 208. ADEC did not explain how its inferences of adverse effects
on the region’s economy or the mine’s “world
competitiveness” could be made without financial information
showing SCR’s impact on the “operation, profitability,
and competitiveness” of the mine. Id. , at 207, 299.
Instead, ADEC reiterated its rural Alaska utility analogy, and
again compared SCR’s cost to the costs of other, less
stringent, control technologies. Id. , at
205–207.

															   The same day, December 10, 1999, EPA issued an
order to ADEC, under §§113(a)(5) and 167 of the Act, 42
U. S. C. §§7413(a)(5) and 7477, prohibiting ADEC
from issuing a PSD permit to Cominco “unless ADEC
satisfactorily documents why SCR is not BACT for the Wartsila
diesel generator [MG–17].” App. to Pet. for Cert. 36a.
In the letter accompanying the order, the Agency stated that
“ADEC’s own analysis supports the determination that
BACT is [SCR], and that ADEC’s decision in the proposed
permit therefore is both arbitrary and erroneous.” App.
149.

															   On February 8, 2000, EPA, again invoking its
authority under §§113(a)(5) and 167 of the Act, issued a
second order, this time prohibiting Cominco from beginning
“construction or modification activities at the Red Dog
mine.” App. to Pet. for Cert. 49a. A third order, issued on
March 7, 2000, superseding and vacating the February 8 order,
generally prohibited Cominco from acting on ADEC’s December
10 PSD permit but allowed limited summer construction. Id. , at 62a–64a. On April 25, 2000, EPA withdrew its
December 10 order. App. 300; App. to Pet. for Cert. 6a. Once ADEC
issued the permit, EPA explained, that order lacked utility. On
July 16, 2003, ADEC granted Cominco a PSD permit to construct
MG–17 with SCR as BACT. Letter from Theodore B. Olson,
Solicitor General, to William K. Suter, Clerk of the Court (Aug.
21, 2003). Under the July 16, 2003, permit, SCR ceases to be BACT
“if and when the case currently pending before the Supreme
Court of the United States of America is decided in favor of the
State of Alaska.” ADEC, Air Quality Construction Permit,
Final Technical Analysis Report, Permit No. 9932–AC005,
Revision 2, p. 7.

															   The day EPA issued its first order against
Cominco, February 8, 2000, ADEC and Cominco petitioned the Court of
Appeals for the Ninth Circuit for review of EPA’s orders.
App. 11. The Agency initially moved to dismiss, urging that the
Court of Appeals lacked subject-matter jurisdiction. In an order
released March 27, 2001, the Ninth Circuit concluded that it had
adjudicatory authority pursuant to 42 U. S. C.
§7607(b)(1), which lodges jurisdiction over challenges to
“any … final [EPA] action” in the Courts of
Appeals. Alaska v. United States EPA , 244
F. 3d 748, 750–751.[ Footnote 10 ]

															   The Court of Appeals resolved the merits in a
judgment released July 30, 2002. 298 F. 3d 814 (CA9). It held
that EPA had authority under §§113(a)(5) and 167 to issue
the contested orders, and that the Agency had properly exercised
its discretion in doing so. Id., at 820–823.
Concerning EPA’s authority under §§113(a)(5) and
167, the Court of Appeals observed first that “the question
presented is what requirements the state must meet”
under the Act to issue a PSD permit, not what the correct BACT
might be. Id. , at 821 (emphasis in original). Concluding
that EPA had “authority to determine the reasonableness or
adequacy of the state’s justification for its
decision,” the Court of Appeals emphasized that the
“provision of a reasoned justification” by a permitting
authority is undeniably a “requirement” of the Act. Ibid. EPA had properly exercised its discretion in issuing
the three orders, the Ninth Circuit ultimately determined, because
(1) Cominco failed to “demonstrat[e] that SCR was
economically infeasible,” and (2) “ADEC failed to
provide a reasoned justification for its elimination of SCR as a
control option.” Id. , at 823. We granted certiorari, 537 U. S. 1186 (2003), to resolve an important question of federal law, i.e. , the scope of EPA’s authority under
§§113(a)(5) and 167, and now affirm the Ninth
Circuit’s judgment.

															II

															   ADEC contested EPA’s orders
under 42 U. S. C. §7607(b)(1), which renders reviewable
in the appropriate federal court of appeals any EPA “final
action.” Before the Ninth Circuit, EPA unsuccessfully urged
that its orders were “interlocutory,” and therefore
unreviewable in court unless and until EPA chose to commence an
enforcement action.[ Footnote
11 ] A pre-enforcement contest could be maintained in the Court
of Appeals under §7607(b)(1), the Ninth Circuit held, for in
the circumstances presented, EPA’s actions had the requisite
finality.

															   It was undisputed, the Court of
Appeals observed, that EPA had spoken its “ ‘last
word’ ” on whether ADEC had adequately justified
its conclusion that Low NOx was the best available control
technology for the MG–17 generator. 244 F. 3d, at 750.
Further, EPA’s orders effectively halted construction of the
MG–17 generator, for Cominco would risk civil and criminal
penalties if it defied a valid EPA directive.

															   In this Court, EPA agrees with the Ninth
Circuit’s finality determination. See Brief for Respondents
16–20; Tr. of Oral Arg. 43–44. We are satisfied that
the Court of Appeals correctly applied the guides we set out in Bennett v. Spear , 520 U. S. 154 ,
177–178 (1997) (to be “final,” agency action must
“mark the ‘consummation’ of the agency’s
decisionmaking process,” and must either determine
“rights or obligations” or occasion “legal
consequences” (internal quotation marks omitted)). As the
Court of Appeals stated, EPA had “asserted its final position
on the factual circumstances” underpinning the Agency’s
orders, 244 F. 3d, at 750, and if EPA’s orders survived
judicial review, Cominco could not escape the practical and legal
consequences (lost costs and vulnerability to penalties) of any
ADEC-permitted construction Cominco endeavored, ibid. No question has been raised here, we note,
about the adequacy of EPA’s preorder procedures under the Due
Process Clause or the Administrative Procedure Act. Cf. Vermont
Yankee Nuclear Power Corp. v. Natural Resources Defense
Council, Inc., 435 U. S. 519 , 544
(1978) (agencies have authority to “fashion their own rules
of procedure,” even when a statute does not specify what
process to use). Furthermore, in response to ADEC’s initial
contention that the record was incomplete, the Ninth Circuit gave
EPA an opportunity to supplement the record, and thereafter
obtained from all parties agreement “that the record as it
stood was adequate to resolve [ADEC’s review
petition].” 298 F. 3d, at 818.

															III

															A

															   Centrally at issue in this case
is the question whether EPA’s oversight role, described by
Congress in CAA §§113(a)(5) and 167, see supra ,
at 7, extends to ensuring that a state permitting authority’s
BACT determination is reasonable in light of the statutory guides.
Sections 113(a)(5) and 167 lodge in the Agency encompassing
supervisory responsibility over the construction and modification
of pollutant emitting facilities in areas covered by the PSD
program. 42 U. S. C. §§7413(a)(5) and 7477. In
notably capacious terms, Congress armed EPA with authority to issue
orders stopping construction when “a State is not acting in
compliance with any [CAA] requirement or prohibition …
relating to the construction of new sources or the modification of
existing sources,” §7413(a)(5), or when
“construction or modification of a major emitting facility
… does not conform to the requirements of [the PSD
program],” §7477.

															   The federal Act enumerates
several “[p]reconstruction requirements” for the PSD
program. §7475. Absent these, “[n]o major emitting
facility … may be constructed.” Ibid. One
express preconstruction requirement is inclusion of a BACT
determination in a facility’s PSD permit.
§§7475(a)(1) and (4). As earlier set out, see supra , at 5–6, the Act defines BACT as “an
emission limitation based on the maximum degree of reduction of [a]
pollutant … which the permitting authority, on a
case-by-case basis, taking into account energy, environmental, and
economic impacts and other costs, determines is achievable for [a]
facility.” §7479(3). Under this formulation, the
permitting authority, ADEC here, exercises primary or initial
responsibility for identifying BACT in line with the Act’s
definition of that term.

															   All parties agree that one of the “many
requirements in the PSD provisions that the EPA may enforce”
is “that a [PSD] permit contain a BACT limitation.”
Brief for Petitioner 34; see id. , at 22, 25 (same). See
also Brief for Respondents 23. It is therefore undisputed that the
Agency may issue an order to stop a facility’s construction
if a PSD permit contains no BACT designation.

															   EPA reads the Act’s definition of BACT,
together with CAA’s explicit listing of BACT as a
“[p]reconstruction requiremen[t],” to mandate not
simply a BACT designation, but a determination of BACT
faithful to the statute’s definition. In keeping with the
broad oversight role §§113(a)(5) and 167 vest in EPA, the
Agency maintains, it may review permits to ensure that a
State’s BACT determination is reasonably moored to the
Act’s provisions. See id., at 24. We hold, as
elaborated below, that the Agency has rationally construed the
Act’s text and that EPA’s construction warrants our
respect and approbation.

															   BACT’s statutory definition requires
selection of an emission control technology that results in the
“maximum” reduction of a pollutant “achievable
for [a] facility” in view of “energy, environmental,
and economic impacts, and other costs.” 42 U. S. C.
§7479(3). This instruction, EPA submits, cabins state
permitting authorities’ discretion by granting only
“authority to make reasonable BACT
determinations,” Brief for Respondents 27 (emphasis in
original), i.e. , decisions made with fidelity to the
Act’s purpose “to insure that economic growth will
occur in a manner consistent with the preservation of existing
clean air resources,” 42 U. S. C. §7470(3). Noting
that state permitting authorities’ statutory discretion is
constrained by CAA’s strong, normative terms
“maximum” and “achievable,”
§7479(3),[ Footnote 12 ]
EPA reads §§113(a)(5) and 167 to empower the federal
Agency to check a state agency’s unreasonably lax BACT
designation. See Brief for Respondents 27.

															   EPA stresses Congress’ reason for
enacting the PSD program—to prevent significant deterioration
of air quality in clean-air areas within a State and in neighboring
States. §§7470(3), (4); see id., at 33. That
aim, EPA urges, is unlikely to be realized absent an EPA
surveillance role that extends to BACT determinations. The Agency
notes in this regard a House Report observation:

															“Without national guidelines for the
prevention of significant deterioration a State deciding to protect
its clean air resources will face a double threat. The prospect is
very real that such a State would lose existing industrial plants
to more permissive States. But additionally the State will likely
become the target of “economic-environmental blackmail”
from new industrial plants that will play one State off against
another with threats to locate in whichever State adopts the most
permissive pollution controls.” H. R. Rep. No.
95–294, p. 134 (1977).

															The House Report further observed that “a
community that sets and enforces strict standards may still find
its air polluted from sources in another community or another
State.” Id. , at 135 (quoting 116 Cong. Rec. 32909
(1970)). Federal agency surveillance of a State’s BACT
designation is needed, EPA asserts, to restrain the
interjurisdictional pressures to which Congress was alert. See
Brief for Respondents 33–34, 43; Brief for Vermont
et al. as Amici Curiae 12 (“If EPA has
authority to ensure a reasonable level of consistency among BACT
determinations nationwide, then every State can feel more confident
about maintaining stringent standards without fear of losing its
current industry or alienating prospective industry.”).

															   The CAA construction EPA advances in this
litigation is reflected in interpretive guides the Agency has
several times published. See App. 268–269 (1983 EPA PSD
guidance memorandum noting the Agency’s “oversight
function”); id. , at 274 (1988 EPA guidance
memorandum stating EPA may find a BACT determination deficient if
it is “not based on a reasoned analysis”); id. , at 281–282 (1993 guidance memorandum stating
that “EPA acts to ensure that the state exercises its
discretion within the bounds of the law” (internal quotation
marks omitted); as to BACT, EPA will not intervene if the state
agency has given “a reasoned justification for the basis of
its decision” (internal quotation marks omitted)). See also
Approval and Promulgation of Air Quality Implementation Plans;
Commonwealth of Virginia—Prevention of Significant
Deterioration Program, 63 Fed. Reg. 13797 (1998) (EPA will
“review whether any determination by the permitting authority
was made on reasonable grounds properly supported on the record,
described in enforceable terms, and consistent with all applicable
requirements”). We “normally accord particular
deference to an agency interpretation of ‘longstanding’
duration,” Barnhart v. Walton, 535 U. S. 212 , 220
(2002) (quoting North Haven Bd. of Ed. v. Bell, 456 U. S. 512 ,
522, n. 12 (1982)), recognizing that “well-reasoned
views” of an expert administrator rest on
“ ‘a body of experience and informed judgment to
which courts and litigants may properly resort for
guidance,’ ” Bragdon v. Abbott, 524 U. S. 624 ,
642 (1998) (quoting Skidmore v. Swift & Co., 323 U. S. 134 ,
139–140 (1944)).

															   We have previously accorded dispositive effect
to EPA’s interpretation of an ambiguous CAA provision. See Chevron U. S. A. Inc. v. Natural Resources
Defense Council, Inc., 467 U. S. 837 , 865–866 (1984); Union Elec., 427 U. S., at 256. The Agency’s
interpretation in this case, presented in internal guidance
memoranda, however, does not qualify for the dispositive force
described in Chevron . See Christensen v. Harris County, 529 U. S. 576 , 587
(2000) (“Interpretations such as those in … policy
statements, agency manuals, and enforcement guidelines, all of
which lack the force of law—do not warrant Chevron -style deference.”); accord, United
States v. Mead Corp., 533 U. S. 218 , 234
(2001). Cogent “administrative interpretations … not
[the] products of formal rulemaking … nevertheless warrant
respect.” Washington State Dept. of Social and Health
Servs. v. Guardianship Estate of Keffeler, 537 U. S. 371 , 385
(2003). We accord EPA’s reading of the relevant statutory
provisions, §§7413(a)(5), 7470(3), 7470(4), 7475(a)(4),
7477, and 7479(3), that measure of respect.

															B

															   ADEC assails the Agency’s
construction of the Act on several grounds. Its arguments do not
persuade us to reject as impermissible EPA’s longstanding,
consistently maintained interpretation.

															   ADEC argues that the statutory
definition of BACT, §7479(3), unambiguously assigns to
“the permitting authority” alone determination of the
control technology qualifying as “best available.”
Brief for Petitioner 21–26. Because the Act places
responsibility for determining BACT with “the permitting
authority,” ADEC urges, CAA excludes federal Agency
surveillance reaching the substance of the BACT decision. Id. , at 22–25. EPA’s enforcement role, ADEC
maintains, is restricted to the requirement “that the permit
contain a BACT limitation.” Id. , at 34.

															   Understandably, Congress entrusted state
permitting authorities with initial responsibility to make BACT
determinations “case-by-case.” §7479(3). A state
agency, no doubt, is best positioned to adjust for local
differences in raw materials or plant configurations, differences
that might make a technology “unavailable” in a
particular area. But the fact that the relevant statutory
guides—“maximum” pollution reduction,
considerations of energy, environmental, and economic
impacts—may not yield a “single, objectively
‘correct’ BACT determination,” id., at
23, surely does not signify that there can be no unreasonable determinations. Nor does Congress’
sensitivity to site-specific factors necessarily imply a design to
preclude in this context meaningful EPA oversight under
§§113(a)(5) and 167. EPA claims no prerogative to
designate the correct BACT; the Agency asserts only the authority
to guard against unreasonable designations. See 298 F. 3d, at
821 (“the question presented is what requirements the state must meet,” not what final substantive
decision the State must make (emphasis in original)).[ Footnote 13 ]

															   Under ADEC’s interpretation, EPA
properly inquires whether a BACT determination appears in a PSD
permit, Brief for Petitioner 34, but not whether that BACT
determination “was made on reasonable grounds properly
supported on the record,” 63 Fed. Reg., at 13797. Congress,
however, vested EPA with explicit and sweeping authority to enforce
CAA “requirements” relating to the construction and
modification of sources under the PSD program, including BACT. We
fail to see why Congress, having expressly endorsed an expansive
surveillance role for EPA in two independent CAA provisions, would
then implicitly preclude the Agency from verifying substantive
compliance with the BACT provisions and, instead, limit EPA’s
superintendence to the insubstantial question whether the state
permitting authority had uttered the key words
“BACT.”

															   We emphasize, however, that EPA’s
rendition of the Act’s less than crystalline text leaves the
“permitting authority” considerable leeway. The Agency
acknowledges “the need to accord appropriate deference”
to States’ BACT designations, Brief for Respondents 43, and
disclaims any intention to “ ‘second guess’
state decisions,” 63 Fed. Reg., at 13797. Only when a state
agency’s BACT determination is “not based on a reasoned
analysis,” App. 274, may EPA step in to ensure that the
statutory requirements are honored.[ Footnote 14 ] EPA adhered to that limited role here,
explaining why ADEC’s BACT determination was
“arbitrary” and contrary to ADEC’s own findings. Id., at 149–150. EPA’s limited but vital role
in enforcing BACT is consistent with a scheme that “places
primary responsibilities and authority with the States, backed by
the Federal Government.” S. Rep. No. 95–127,
p. 29.

															   ADEC also points to 42 U. S. C.
§7475(a)(8), a provision of the Act expressly requiring, in a
limited category of cases, EPA approval of a state permitting
authority’s BACT determination before a facility may be
constructed. See Brief for Petitioner 25; Reply Brief for
Petitioner 6. Had Congress intended EPA superintendence of BACT
determinations, ADEC urges, Congress would have said so expressly
by mandating Agency approval of all, not merely some, BACT
determinations. Brief for Petitioner 25–26. ADEC’s
argument overlooks the obvious difference between a statutory requirement , e.g. , §7475(a)(8), and a
statutory authorization . Sections 113(a)(5) and 167
sensibly do not require EPA approval of all state BACT
determinations, they simply authorize EPA to act in the unusual
case in which a state permitting authority has determined BACT
arbitrarily. EPA recognizes that its authorization to issue a stop
order may be exercised only when a state permitting
authority’s decision is unreasonable; in contrast, a required
approval may be withheld if EPA would come to a different
determination on the merits. See, e.g. , 57 Fed. Reg. 28095
(1992) (“EPA acknowledges that states have the primary role
in administering and enforcing the various components of the PSD
program. States have been largely successful in this effort, and
EPA’s involvement in interpretative and enforcement issues is
limited to only a small number of cases.”).

															   Even if the Act imposes a requirement of
reasoned justification for a BACT determination, ADEC ultimately
argues, such a requirement may be enforced only through state
administrative and judicial processes. Brief for Petitioner
34–38.[ Footnote 15 ]
State review of BACT decisions, according to ADEC, allows
development of an adequate factual record, properly imposes the
burden of persuasion on EPA when it challenges a State’s BACT
determination, and promotes certainty. Id. , at
36–37. Unless EPA review of BACT determinations is channeled
into state administrative and judicial forums, ADEC suggests,
“there is nothing to prevent the EPA from invalidating a BACT
determination at any time—months, even years, after a permit
has been issued.” Id. , at 35.

															   It would be unusual, to say the least, for
Congress to remit a federal agency enforcing federal law solely to
state court. We decline to read such an uncommon regime into the
Act’s silence. EPA, the expert federal agency charged with
enforcing the Act, has interpreted the BACT provisions and its own
§§113(a)(5) and 167 enforcement powers not to require
recourse to state processes before stopping a facility’s
construction. See supra , at 17–21. That rational
interpretation, we agree, is surely permissible.[ Footnote 16 ]

															   Nor are we persuaded by ADEC’s practical
concerns. We see no reason to conclude that an appropriate record
generally cannot be developed to allow informed federal-court
review when EPA disputes a BACT decision’s reasonableness.
ADEC contends that, in this very case, “the State’s
BACT determination was reviewed by the Ninth Circuit on an
incomplete record.” Brief for Petitioner 37. ADEC, however,
offers no particulars to back up its assertion that the Court of
Appeals proceeded on an inadequate evidentiary record. We note
again that the Ninth Circuit ordered EPA to submit a complete
administrative record. 298 F. 3d, at 818. After the Agency declared
that the record was complete, “all the parties effectively
agreed that the record as it stood was adequate to resolve the
issues on appeal.” Ibid. As to the burdens of production and
persuasion, nothing in the Act suggests that EPA gains a
proof-related tactical advantage by issuing a stop-construction
order instead of seeking relief through a civil action. But cf. post , at 9 (EPA authority to issue stop-construction
orders creates “the anomaly of shifting the burden of
pleading and of initiating litigation from EPA to the
State”). Correspondingly, nothing in our decision today
invites or permits EPA to achieve an unfair advantage through its
choice of litigation forum. In granting EPA a choice between
initiating a civil action and exercising its
stop-construction-order authority, see supra , at 7, 26,
n. 15, Congress nowhere suggested that the allocation of proof
burdens would differ depending upon which enforcement route EPA
selected. The point ought not to be left in doubt. Accordingly, we
hold that in either an EPA-initiated civil action or a challenge to
an EPA stop-construction order filed in state or federal court, the
production and persuasion burdens remain with EPA and the
underlying question a reviewing court resolves remains the same:
Whether the state agency’s BACT determination was reasonable,
in light of the statutory guides and the state administrative
record. See supra , at 18–19, 24.[ Footnote 17 ]

															   The Ninth Circuit’s review of
EPA’s order is in keeping with our holding that EPA may not
reduce the burden it must carry by electing to invoke its
stop-construction-order authority. Specifically, the Court of
Appeals rested its judgment on what EPA showed from ADEC’s
own report: “(1) Cominco failed to meet its burden of
demonstrating [to ADEC] that SCR was economically infeasible; and
(2) ADEC failed to provide a reasoned justification for its
elimination of SCR as a control option.” 298 F. 3d, at 823.
EPA’s conclusions, and the basis for them, support the Court
of Appeals’ determination that the federal Agency’s
grounds for issuing the orders under review were not
“arbitrar[y] and capriciou[s].” Ibid. Our own
analysis, infra at 30–35, similarly hinges on the
question whether ADEC’s BACT determination was a reasonable
one. Our analysis would have taken the same path had EPA initiated
a civil action pursuant to §113(a)(5)(C), or if the suit under
consideration had been filed initially in state court.

															   Nor do we find compelling ADEC’s
suggestion, reiterated by the dissent, that, if state courts are
not the exclusive judicial arbiters, EPA would be free to
invalidate a BACT determination “months, even years, after a
permit has been issued.” Brief for Petitioner 35; post , at 11–13. This case threatens no such
development. It involves preconstruction orders issued by EPA, see supra , at 14, not postconstruction federal Agency
directives. EPA itself regards it as “imperative” to
act on a timely basis, recognizing that courts are “less
likely to require new sources to accept more stringent permit
conditions the farther planning and construction have
progressed.” App. 273 (July 15, 1988, EPA guidance
memorandum). In the one instance of untimely EPA action ADEC
identifies, the federal courts declined to permit enforcement to
proceed. See United States v. AM General Corp. ,
34 F. 3d 472, 475 (CA7 1994) (affirming District Court’s
dismissal of an EPA-initiated enforcement action where EPA did not
act until well after the facility received a PSD permit and
completed plant modifications). EPA, we are confident, could not
indulge in the inequitable conduct ADEC and the dissent hypothesize
while the federal courts sit to review EPA’s actions. Cf. Walz v. Tax Comm’n of City of New York, 397 U. S. 664 ,
678–679 (1970); Panhandle Oil Co. v. Mississippi
ex rel. Knox , 277 U. S. 218 , 223
(1928) (Holmes, J., dissenting), overruled in part by Alabama v. King & Boozer, 314 U. S. 1 , 8–9
(1941)).

															   In sum, EPA interprets the Act to allow
substantive federal Agency surveillance of state permitting
authorities’ BACT determinations subject to federal court
review. We credit EPA’s longstanding construction of the Act
and confirm EPA’s authority, pursuant to
§§113(a)(5) and 167, to rule on the reasonableness of
BACT decisions by state permitting authorities.

															IV

															A

															   We turn finally, and more
particularly, to the reasons why we conclude that EPA properly
exercised its statutory authority in this case. ADEC urges that,
even if the Act allows the Agency to issue stop-construction orders
when a state permitting authority unreasonably determines BACT, EPA
acted impermissibly in this instance. See Brief for Petitioner
39–48. We note, first, EPA’s threshold objection.
ADEC’s petition to this Court questioned whether the Act
accorded EPA oversight authority with respect to a State’s
BACT determination. Pet. for Cert. 13–22. ADEC did not
present, as a discrete issue, the question whether EPA, assuming it
had authority to review the substance of a state BACT
determination, nevertheless abused its authority by countermanding
ADEC’s permit for the Red Dog Mine expansion. See Brief for
Respondents 44–45; cf. Reply Brief for Petitioner
15–16, n. 12 (“EPA asserts authority to overturn
only ‘arbitrary or unreasoned’ state BACT
determinations… . Thus, whether the State issued a
reasoned justification is ‘fairly included’ within the
question presented[.]”). Treating the case-specific issue as
embraced within the sole question presented, we are satisfied that
EPA did not act arbitrarily in finding that ADEC furnished no
tenable accounting for its determination that Low NOx was BACT for
MG–17.

															   Because the Act itself does not
specify a standard for judicial review in this instance,[ Footnote 18 ] we apply the familiar
default standard of the Administrative Procedure Act, 5 U.
S. C. §706(2)(A), and ask whether the Agency’s
action was “arbitrary, capricious, an abuse of discretion, or
otherwise not in accordance with law.” Even when an agency
explains its decision with “less than ideal clarity,” a
reviewing court will not upset the decision on that account
“if the agency’s path may reasonably be
discerned.” Bowman Transp., Inc. v. Arkansas&nbhyph;Best Freight System, Inc., 419 U. S. 281 , 286
(1974). EPA’s three skeletal orders to ADEC and Cominco
surely are not composed with ideal clarity. These orders, however,
are properly read together with accompanying explanatory
correspondence from EPA; so read, the Agency’s comments and
orders adequately ground the determination that ADEC’s
acceptance of Low NOx for MG–17 was unreasonable given the
facts ADEC found.

															   In the two draft permits and the final permit,
ADEC formally followed the EPA-recommended top-down methodology to
determine BACT, as Cominco had done in its application. App. 61,
109, 175; see supra , at 9–10. Employing that
methodology in the May 1999 draft permit, ADEC first concluded that
SCR was the most stringent emission-control technology that was
both “technically and economically feasible.” App. 65;
see supra , at 9–10. That technology should have been
designated BACT absent “technical considerations, or energy,
environmental, or economic impacts justif[ying] a conclusion that
[SCR was] not ‘achievable’ in [this] case.” New
Source Review Manual, p . B2; App. 61–62. ADEC
nevertheless selected Low NOx as BACT; ADEC did so in May 1999
based on Cominco’s suggestion that fitting all Red Dog Mine
generators with Low NOx would reduce aggregate emissions. Id., at 87, 111–112; see supra , at
10–11.

															   In September and December 1999, ADEC again
rejected SCR as BACT but no longer relied on Cominco’s
suggestion that it could reduce aggregate emissions by equipping
all generators with Low NOx. See supra , at 12–14.
ADEC candidly stated that it aimed “[t]o support
Cominco’s Red Dog Mine Production Rate Increase Project, and
its contributions to the region.” App. 208. In these second
and third rounds, ADEC rested its selection of Low NOx squarely and
solely on SCR’s “disproportionate cost.” Id. , at 116; id. , at 112–117,
203–208; supra , at 12–14.

															   EPA concluded that ADEC’s switch from
finding SCR economically feasible in May 1999 to finding SCR
economically infeasible in September 1999 had no factual basis in
the record. See App. 138. In the September and December 1999
technical analyses, ADEC acknowledged that “no judgment
[could then] be made as to the impact of [SCR’s] cost on the
operation, profitability, and competitiveness of the Red Dog
Mine.” Id. , at 116, 207. ADEC nevertheless concluded
that SCR would threaten both the Red Dog Mine’s “unique
and continuing impact on the economic diversity” of northwest
Alaska and the mine’s “world competitiveness.” Id. , at 208. ADEC also stressed the mine’s role as
employer in an area with “historical high unemployment and
limited permanent year-round job opportunities.” Id. , at 207.

															   We do not see how ADEC, having acknowledged
that no determination “[could] be made as to the impact of
[SCR’s] cost on the operation … and competitiveness of
the [mine],” ibid. , could simultaneously proffer
threats to the mine’s operation or competitiveness as reasons
for declaring SCR economically infeasible. ADEC, indeed,
forthrightly explained why it was disarmed from reaching any
judgment on whether, or to what extent, implementation of SCR would
adversely affect the mine’s operation or profitability:
Cominco had declined to provide the relevant financial data,
disputing the need for such information and citing
“confidentiality” concerns, id. , at 134; see supra , at 13; 298 F. 3d, at 823 (“Cominco
failed to meet its burden of demonstrating that SCR was
economically infeasible.”). No record evidence suggests that
the mine, were it to use SCR for its new generator, would be
obliged to cut personnel, or raise zinc prices. Absent evidence of
that order, ADEC lacked cause for selecting Low NOx as BACT based
on the more stringent control’s impact on the mine’s
operation or competitiveness.

															   Nor has ADEC otherwise justified its choice of
Low NOx. To bolster its assertion that SCR was too expensive, ADEC
invoked four BACT determinations made in regard to diesel
generators used for primary power production; BACT’s cost, in
those instances, ranged from $0 to $936 per ton of nitrogen oxide
removed. App. 205–206; supra , at 14. ADEC itself,
however, had previously found SCR’s per-ton cost, then
estimated as $2,279, to be “well within what ADEC and EPA
considers economically feasible.” App. 84; cf. id. ,
at 204 (estimating SCR’s per ton cost to be $2,100). No
reasoned explanation for ADEC’s retreat from this position
appears in the final permit. See id. , at 138
(“[SCR’s cost falls] well within the range of costs EPA
has seen permitting authorities nationwide accept as economically
feasible for NOx control except where there are compelling site
specific factors that indicate otherwise.”). Tellingly, as to
examples of low-cost BACT urged by Cominco, ADEC acknowledged:
“The cited examples of engines permitted in Alaska without
requiring SCR are not valid examples as they either took place over
18 months ago or were not used for similar purposes.” Id. , at 233–234 (footnote omitted). ADEC added that
it has indeed “permitted [Alaska] projects requiring
SCR.” Id. , at 234. Further, EPA rejected
ADEC’s comparison between the mine and a rural utility, see supra , at 12–13, because “no facts exist to
suggest that the ‘economic impact’ of the incrementally
higher cost of SCR on the world’s largest producer of zinc
concentrates would be anything like its impact on a rural,
non-profit utility that must pass costs on to a small base of
individual consumers.” Brief for Respondents 49; App.
138–139 (similar observation in Nov. 10, 1999, EPA
letter).

															   ADEC’s basis for selecting Low NOx thus
reduces to a readiness “[t]o support Cominco’s Red Dog
Mine Production Rate Increase Project, and its contributions to the
region.” Id., at 208. This justification, however,
hardly meets ADEC’s own standard of a “source-specific
… economic impac[t] which demonstrate[s] [SCR] to be
inappropriate as BACT.” Id. , at 177. In short, as
the Ninth Circuit determined, EPA validly issued stop orders
because ADEC’s BACT designation simply did not qualify as
reasonable in light of the statutory guides.

															   In its briefs to this Court, ADEC nonetheless
justifies its selection of Low NOx as BACT for MG–17 on the
ground that lower aggregate emissions would result from
Cominco’s “agree[ment] to install Low NOx on all its generators.” Brief for Petitioner 42, and
n. 12 (emphasis added); id. , at 29; Reply Brief for
Petitioner 19, n. 16. We need not dwell on ADEC’s
attempt to resurrect Cominco’s emissions-offsetting
suggestion, see supra, at 10–11, adopted in the
initial May 1999 draft permit, but thereafter dropped. As ADEC
acknowledges, the final PSD permit did not offset
MG–17’s emissions against those of the mine’s six
existing generators, installations that were not subject to BACT.
Brief for Petitioner 42, n. 12; App. 149. ADEC recognized in
September and December 1999 that a State may treat emissions from
several pollutant sources as falling under one
“bubble”[ Footnote
19 ] for PSD permit purposes only if every pollutant source so
aggregated is “part of the permit action.” Id., at 111, 199. Offsetting new emissions against those
from any of the mine’s other generators, ADEC agreed,
“[was] not a consideration of the BACT review provided for by
the applicable law or guidelines,” for those generators
remained outside the permit’s compass. Id., at 112,
199. ADEC plainly did not, and could not, base its December 10,
1999 permit and technical analysis on an emissions-offsetting
rationale drawing in generators not subject to BACT. Id., at 111–112.[ Footnote
20 ] By that time, only MG–17 was “part of the
permit action.” Id. , at 111, 199.

															B

															   We emphasize that today’s
disposition does not impede ADEC from revisiting the BACT
determination in question. In letters and orders throughout the
permitting process, EPA repeatedly commented that it was open to
ADEC to prepare “an appropriate record” supporting its
selection of Low NOx as BACT. Tr. of Oral Arg. 35; see App. 127
(attachment to Sept. 28, 1999, EPA letter to ADEC, stating
“an analysis of whether requiring Cominco to install and
operate [SCR] would have any adverse economic impacts upon Cominco
specifically” might demonstrate SCR’s economic
infeasibility); id. , at 150 (letter accompanying
EPA’s Dec. 10, 1999, finding of noncompliance and order
reiterating the Agency’s willingness to “review and
consider any additional information or analyses provided by ADEC or
Cominco” on Low NOx as BACT); App. to Pet. for Cert. 36a (EPA
Dec. 10, 1999, order inviting ADEC to justify its choice of Low NOx
by “document[ing] why SCR is not BACT [for
MG–17]”); id. , at 49a (similar statement in
Feb. 8, 2000, order). At oral argument, counsel for EPA reaffirmed
that, “absolutely,” ADEC could reconsider the matter
and, on an “appropriate record,” endeavor to support
Low NOx as BACT. Tr. of Oral Arg. 35.[ Footnote 21 ] We see no reason not to take EPA at its
word.

															* * *

															   In sum, we conclude that EPA has
supervisory authority over the reasonableness of state permitting
authorities’ BACT determinations and may issue a stop
construction order, under §§113(a)(5) and 167, if a BACT
selection is not reasonable. We further conclude that, in
exercising that authority, the Agency did not act arbitrarily or
capriciously in finding that ADEC’s BACT decision in this
instance lacked evidentiary support. EPA’s orders, therefore,
were neither arbitrary nor capricious. The judgment of the Court of
Appeals is accordingly

															Affirmed. Footnote 1 Emissions levels for nitrogen dioxide, a
regulated pollutant under the Act, are defined in terms of
quantities of all oxides of nitrogen. R. Belden, Clean Air Act 47,
n. 11 (2001). “The term nitrogen oxides refers to a
family of compounds of nitrogen and oxygen. The principal nitrogen
oxides component present in the atmosphere at any time is nitrogen
dioxides. Combustion sources emit mostly nitric oxide, with some
nitrogen dioxide. Upon entering the atmosphere, the nitric oxide
changes rapidly, mostly to nitrogen dioxide.” EPA, Prevention
of Significant Deterioration for Nitrogen Oxides, 53 Fed. Reg.
40656 (1988). Nitrogen oxides are also termed
“NOx.” Footnote 2 Sierra Club v. Ruckelshaus ,
344 F. Supp. 253 (DC 1972), aff’d per curiam , 4
E. R. C. 1815, 2 Env. L. Rep. 20656 (CADC 1972),
aff’d by an equally divided court sub nom. Fri v. Sierra Club , 412 U. S. 541 (1973). Footnote 3 The PSD program also requires visibility
control measures, 42 U. S. C. §§7491–7492, not
at issue in this case. Footnote 4 As enacted in 1977, §113(a)(5) extended
only to solid waste combustion and sources in nonattainment areas.
See Title I, §111(a), 91 Stat. 685. Congress extended
§113(a)(5) in 1990 amendments to the Act to cover attainment
areas, and thus to encompass enforcement of PSD permitting
requirements. Title VII, 104 Stat. 2672. Footnote 5 SCR requires injections of “ammonia or
urea into the exhaust before the exhaust enters a catalyst bed made
with vanadium, titanium, or platinum. The reduction reaction occurs
when the flue gas passes over the catalyst bed where the NOx and
ammonia combine to become nitrogen, oxygen, and water
… .” App. 71. Footnote 6 In Low NOx, changes are made to a generator
to improve fuel atomization and modify the combustion space to
enhance the mixing of air and fuel. Id., at 75. Footnote 7 Nothing in the Act or its implementing
regulations mandates top-down analysis. See 42 U. S. C.
§7479(3); 40 CFR §52.21(j) (2002). EPA represents that
permitting authorities “commonly” use top-down
methodology. Brief for Respondents 3. Footnote 8 Two generators already were fitted with a
technology called Fuel Injection Timing Retard that results in a
20% to 30% reduction in nitrogen oxide emissions. App. 75–76,
86. Footnote 9 Rather than subject MG–1, MG–3,
MG–4, and MG–5 to BACT, ADEC and Cominco “agreed
to permit conditions that would require low NOx controls on
MG–1, MG–3, MG–4, and MG–5, and emission
limits that reflect the previous ‘bubbled’ limits.
Under this approach, the permit would result in no increase in
actual or allowable emissions from any of these engines and the
installation of BACT would not be necessary for these four
units.” Id., at 149. EPA found no cause to question
this ADEC-Cominco agreement. Ibid. Footnote 10 At oral argument, counsel for EPA
confirmed that the Agency no longer questions the Court of
Appeals’ adjudicatory authority, satisfied that the finality
requirement was met because the stop-construction order imposed
“new legal obligations on Cominco.” Tr. of Oral Arg.
43–44 (punctuation omitted). Footnote 11 Such an action would lie in district
court, under 42 U. S. C. §7413(b). Footnote 12 Formulations similar to the BACT
definition’s “maximum degree of [pollutant] reduction
… achievable” appear in the Act’s standards for
new sources in nonattainment areas, 42 U. S. C.
§§7501(3) and 7503(a)(2) (“lowest achievable
emission rate”) (internal quotation marks omitted), and its
technology-based standard for hazardous emissions, §7412(d)(2)
(“maximum degree of reduction …
achievable”). Footnote 13 The dissent admonishes that “a
statute is to be read as a whole.” Post , at 3 (quoting King v. St. Vincent’s Hospital, 502 U. S. 215 , 221
(1991)). We give that unexceptional principle effect by attending
both to the unequivocal grant of supervisory authority to EPA in
§§113(a)(5) and 167, and to the statutory control on
permitting authorities’ discretion contained in the BACT
definition, 42 U. S. C. §7479(3). It is, moreover,
“a cardinal principle of statutory construction’ that
‘a statute ought, upon the whole, to be so construed that, if
it can be prevented, no clause, sentence, or word shall be
superfluous, void, or insignificant.” TRW Inc. v. Andrews, 534
U. S. 19 , 31 (2001) (quoting Duncan v. Walker, 533
U. S. 167 , 174 (2001)). The Act instructs permitting
authorities to identify the “best,”
“maximum” emission reduction technique, taking account
of costs. 42 U. S. C. §7479(3). The dissent does not
explain how that instruction can be construed as something other
than a constraint on permitting authorities’ discretion.
Ultimately, the dissent recognizes the essential statutory
requirement: selection of “the technology that can best reduce pollution within practical constraints.” Post , at 4 (emphasis added).

															   Nor do we find enlightening Congress’
inclusion of the word “determines” in the BACT
definition. Post, at 2. Even under the dissent’s
view of the Act, state permitting authorities’ BACT
determinations are not “conclusiv[e] and
authoritativ[e].” Ibid. (internal quotation marks
and citation omitted). As the dissent develops at length, review of
such BACT determinations may be sought in state court. Post, at 7–11; Alaska Stat. §44.62.560 (2002).
And EPA actions, of course, are subject to “the process of
judicial review,” see post , at 1, Congress empowered
federal courts to provide, here in 42 U. S. C.
§7607(b)(1). See supra , at 16–17. Footnote 14 According to the Agency, “[i]t has
proven to be relatively rare that a state agency has put EPA in the
position of having to exercise [its] authority,” noting that
only two other reported judicial decisions concern EPA orders
occasioned by States’ faulty BACT determinations. Brief for
Respondents 30, and n. 9 (citing Allsteel, Inc. v. EPA , 25 F. 3d 312 (CA6 1994), and Solar Turbines
Inc. v. Seif , 879 F. 2d 1073 (CA3 1989)).
EPA’s restrained and moderate use of its authority hardly
supports the dissent’s speculation that the federal Agency
will “displac[e]” or “degrad[e]” state
agencies or relegate them to the performance of
“ministerial” functions. Post , at 14,
16–17. Nor has EPA ever asserted authority to override a
state-court judgment. Cf. post , at 10. Preclusion
principles, we note in this regard, unquestionably do apply against
the United States, its agencies and officers. See, e.g. , Montana v. United States, 440 U. S. 147 (1979). Footnote 15 From the availability of state-court judicial
review, the dissent concludes, it necessarily “follows that
EPA … must take the same procedural steps,” of filing
suit in state court, as any other person or entity seeking to
challenge the issuance of a PSD permit. Post , at 8.
Interpreted otherwise, the dissent asserts, the Act contains a
“loophole” that allows an EPA “end run around the
State’s process.” Post, at 10. In designing
the Act, however, Congress often gave EPA a choice of enforcement
measures. For example, EPA has three options to address a failure
to comply with new source requirements. Compare 42 U. S. C.
§7413(a)(5)(A) (EPA may “issue an order prohibiting the
construction or modification of any major stationary
source”), with §7413(a)(5)(B) (EPA may “issue an
administrative penalty order”), and §7413(a)(5)(C) (EPA
may “bring a civil action”). Other sections of the Act
provide EPA with similar options. See, e.g. ,
§§7413(a)(1)–(a)(3). Following the dissent’s
logic, EPA’s authority to bring a civil action would rule
out, as a “loophole,” its authority to issue a
stop-construction order.

															   Moreover, the existence of concurrent
authority is hardly at odds with the Act. As ADEC itself concedes,
EPA can issue a checking order if a PSD permit lacks a BACT
determination, Brief for Petitioner 34, even if state-court
jurisdiction could be invoked instead. Footnote 16 Experience, we have already noted, see supra , at 24–25, n. 14, affords no grounding for the
dissent’s predictions that EPA oversight, which is undeniably
subject to federal-court review, will “rewor[k] … the
balance between State and Federal Governments” and threaten
state courts’ independence. Post , at
10–12. Footnote 17 “[L]ooking for the burden of pleading
is not a foolproof guide to the allocation of the burdens of proof.
The latter burdens do not invariably follow the pleadings.” 2
J. Strong, McCormick on Evidence §337, pp. 411–412 (5th
ed. 1999). No “single principle or rule … solve[s] all
cases and afford[s] a general test for ascertaining the
incidence” of proof burdens. 9 J. Wigmore, Evidence
§2486, p. 288 (J. Chadbourn rev. ed. 1981) (emphasis deleted).
“[I]n a case of first impression,” which we address
today, “reference to which party has pleaded a fact is no
help at all.” McCormick, supra , at 412. Among other
considerations, allocations of burdens of production and persuasion
may depend on which party—plaintiff or defendant, petitioner
or respondent—has made the “affirmative
allegation” or “presumably has peculiar means of
knowledge.” Wigmore, supra , at 288, 290 (emphases
deleted); accord, Campbell v. United States, 365 U. S. 85 , 96
(1961). Footnote 18 The Court of Appeals referred to 42 U.
S. C. §7607(d)(9)(A) when it considered whether
EPA’s decision was “arbitrary, capricious, an abuse of
discretion, or otherwise not in accordance with law.” 298
F. 3d 814, 822 (CA9 2002). Section 7607(d)(9), however,
applies only to the “subsection” concerning rulemaking
in which it is embedded. Footnote 19 Cf. Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U. S. 837 , 853–859 (1984)
(upholding EPA regulations allowing States to treat all
pollutant-emitting devices within the same stationary source in a
nonattainment area as though encased in a single
“bubble”). Footnote 20 The May 4, 1999, draft permit considered
whether adding Low NOx to seven generators would result in lower
emissions than adding SCR to only two and choosing one of the
latter as a standby unit. App. 86–87. Before December 10,
1999, however, Cominco agreed to install Low NOx controls on four
of the mine’s six existing generators—MG–1,
MG–3, MG–4, and MG5—in order to increase use of
those generators without exceeding the 1994 PSD permit’s
operating restriction. Id., at 149. Having agreed to use
Low NOx on four generators, Cominco could propose in the December
10, 1999, permit only the addition of Low NOx to two
generators—MG–2 and MG–6—to offset
increases in emissions from MG–17. No facts in the record
support any suggestion that addition of Low NOx to three
generators, MG–2, MG–6, and MG–17, would result
in lower aggregate emissions than the addition of SCR to
MG–17 alone. Footnote 21 The dissent is daunted by the hypothesis that
“[b]ecause there can always be an additional procedure to
ensure that the preceding process was followed,” the State
“may never reach” the goal of issuing a permit. Post , at 14 (“The majority creates a sort of
Zeno’s paradox for state agencies.”). Again, the
dissent can point to no instance in which EPA has indulged in any
piling of process upon process. See supra , at 27,
n. 16. KENNEDY, J., DISSENTING ALASKA DEPT. OF ENVIRONMENTALCONSERVATION V. EPA 540 U. S. ____ (2004) SUPREME COURT OF THE UNITED STATES NO. 02-658 ALASKA DEPARTMENT OF ENVIRONMENTAL CONSERVATION,
PETITIONER v. ENVIRON- MENTAL PROTECTION AGENCY
et al.

															on writ of certiorari to the united states court of
appeals for the ninth circuit

															[January 21, 2004]

															   Justice Kennedy, with whom The
Chief Justice, Justice Scalia, and Justice Thomas join,
dissenting.

															   The majority, in my respectful
view, rests its holding on mistaken premises, for its reasoning
conflicts with the express language of the Clean Air Act (CAA or
Act), with sound rules of administrative law, and with principles
that preserve the integrity of States in our federal system. The
State of Alaska had in place procedures that were in full
compliance with the governing statute and accompanying regulations
promulgated by the Environmental Protection Agency (EPA). As I
understand the opinion of the Court and the parties’
submissions, there is no disagreement on this point. Alaska
followed these procedures to determine the best available control
technology (BACT). EPA, however, sought to overturn the
State’s decision, not by the process of judicial review, but
by administrative fiat. The Court errs, in my judgment, by failing
to hold that EPA, based on nothing more than its substantive
disagreement with the State’s discretionary judgment,
exceeded its powers in setting aside Alaska’s BACT
determination.

															I

															   As the majority explains, the
case begins with §§113(a)(5) and 167 of the Act. 42 U.
S. C. §§7413(a)(5), 7477. These provisions give EPA
authority to enforce “requirements” of the CAA. The
meaning of the word “requiremen[t],” though, is not
defined in these provisions. Other provisions of the Act must be
consulted. All parties agree that the requirement in this case is
the “preconstruction requiremen[t]” that a “major
emitting facility” be “subject to the best available
technology [BACT] for each pollutant subject to regulation under
this chapter emitted from, or which results from, such
facility.” §7475(a)(4). BACT, in turn, is defined as

															“an emission limitation based on the maximum
degree of reduction of each pollutant subject to regulation under
this chapter emitted from or which results from any major emitting
facility, which the permitting authority, on a case-by-case basis,
taking into account energy, environmental, and economic impacts and
other costs, determines is achievable for such facility through
application of production processes and available methods, systems,
and techniques … .” §7479(3).

															   The majority holds that, under
the CAA, state agencies are vested with “initial
responsibility for identifying BACT in line with the Act’s
definition of that term” and that EPA has a “broad
oversight role” to ensure that a State’s BACT
determination is “reasonably moored to the Act’s
provisions.” Ante , at 18–19. The statute,
however, contemplates no such arrangement. It directs the
“permitting authority”—here, the Alaska
Department of Environmental Conservation (ADEC)—to
“determine” what constitutes BACT. To
“determine” is not simply to make an initial
recommendation that can later be overturned. It is “[t]o
decide or settle … conclusively and authoritatively.”
American Heritage Dictionary 495 (4th ed. 2000). Cf. 5 U.
S. C. §554 (“to be determined on the record after
opportunity for an agency hearing”).

															   The BACT definition presumes that the
permitting authority will exercise discretion. It presumes, in
addition, that the BACT decision will accord full consideration to
the statutory factors and other relevant and necessary criteria.
Contrary to the majority’s holding, the statute does not
direct the State to find as BACT the technology that results in the
“maximum reduction of a pollutant achievable for [a]
facility” in the abstract. Ante, at 19 (internal
quotation marks omitted). Indeed, for a State to do so without
regard to the other mandatory criteria would be to ignore the words
of the statute. The Act requires a more comprehensive judgment. It
provides that the permitting authority must “tak[e] into
account” a set of contextual
considerations—“energy, environmental, and economic
impacts and other costs”—to identify the best control
technology “on a case-by-case basis.” 42 U. S. C.
§7479(3). The majority reaches its narrow view of the scope of
the State’s discretion only by wresting two adjectives,
“maximum” and “achievable,” out of context.
In doing so, it ignores “the cardinal rule that a statute is
to be read as a whole.” King v. St.
Vincent’s Hospital, 502 U. S. 215 , 221
(1991).

															   To be sure, §§113(a)(5) and 167
authorize EPA to enforce requirements of the Act. These provisions,
however, do not limit the States’ latitude and responsibility
to balance all the statutory factors in making their discretionary
judgments. If a State has complied with the Act’s
requirements, §§113(a)(5) and 167 are not implicated and
can supply no separate basis for EPA to exercise a supervisory role
over a State’s discretionary decision. The Court of Appeals
for the Ninth Circuit had it altogether backwards when it reasoned
that, “because neither Section 113(a)(5) nor Section 167
contains any exemption for requirements that involve the
state’s exercise of discretion,” EPA had the authority
to issue orders countermanding the State’s BACT
determination. 298 F. 3d 814, 820 (2002). The question is not
whether the two sections contain any exemption. Rather, it is about
the nature of the Act’s requirements and whether EPA has the
authority to set aside a BACT determination when no requirement of
the Act was violated in the first place. In affirming the judgment
of the Court of Appeals, the majority repeats the same analytical
error. See ante, at 24 (“We fail to see why
Congress, having expressly endorsed an expansive surveillance role
for EPA in two independent CAA provisions, would then implicitly
preclude the Agency from verifying substantive compliance with
[BACT] …”). When the statute is read as a whole, it is
clear that the CAA commits BACT determinations to the discretion of
the relevant permitting authorities. Unless an objecting party,
including EPA, prevails on judicial review, the determinations are
conclusive.

															   Here the state agency, ADEC, recognized it was
required to make a BACT determination. It issued two detailed
reports in response to comments by interested parties and concluded
that Low Nitrogen Oxide (NOx) was BACT. The requirement that the
agency weigh the list of statutory factors, study all other
relevant considerations, and decide the technology that can best
reduce pollution within practical constraints was met in full. As
even EPA acknowledged, ADEC “provid[ed] a detailed accounting
of the process.” App. 286. This is not a case, then, where
the state agency failed to have a BACT review procedure in place or
altogether refused to apply the statute’s formal
requirements. EPA’s only quarrel is with ADEC’s
substantive conclusion. In disagreeing with ADEC, EPA’s sole
contention, in the section of its order titled “Findings of Fact ,” is that “SCR is BACT.” App. to
Pet. for Cert. 30a, 34a (emphasis added). In addition, EPA does not
allege that using Low NOx would violate other CAA requirements,
such as the National Ambient Air Quality Standards, Alaska’s
Prevention of Significant Deterioration (PSD) increments, or other
applicable emission standards, see 42 U. S. C.
§7475(a)(3). On this state of the record there is no deviation
from any statutory “requirement.” As a result, EPA has
no statutory basis to invoke the enforcement authority of
§§113(a)(5) and 167.

															   When Congress intends to give EPA general
supervisory authority, it says so in clear terms. In addition to
requiring EPA’s advance approval of BACT determinations in
some instances, 42 U. S. C. §7475(a)(8), the statute
grants EPA powers to block the construction or operation of
polluting sources in circumstances not at issue here,
§§7426(b), (c)(1), 7410(a)(2)(D)(i). Outside the context
of the CAA, Congress likewise knows how to establish federal
oversight in unambiguous language. See, e.g. , 42 U.
S. C. §1396a(a)(13)(A) (1994 ed.) (requiring, under the
Medicaid Act, reimbursement according to rates that a “State
finds, and makes assurances satisfactory to the Secretary [of
Health and Human Services], are reasonable and adequate to meet the
costs which must be incurred by efficiently and economically
operated facilities”); Wilder v. Virginia
Hospital Assn., 496 U. S. 498 (1990). No
analogous language is used in the statutory definition of BACT.

															   EPA insists it needs oversight authority to
prevent a “race to the bottom,” where jurisdictions
compete with each other to lower environmental standards to attract
new industries and keep existing businesses within their borders.
Whatever the merits of these arguments as a general matter,
EPA’s distrust of state agencies is inconsistent with the
Act’s clear mandate that States bear the primary role in
controlling pollution and, here, the exclusive role in making BACT
determinations. In “cho[osing] not to dictate a Federal
response to balancing sometimes conflicting goals” at the
expense of “[m]aximum flexibility and State
discretion,” H. R. Rep. No. 95–294, p. 146
(1977), Congress made the overriding judgment that States are more
responsive to local conditions and can strike the right balance
between preserving environmental quality and advancing competing
objectives. By assigning certain functions to the States, Congress
assumed they would have a stake in implementing the environmental
objectives of the Act. At the same time, Congress charged EPA with
setting ambient standards and enforcing emission limits, 42 U.
S. C. §7475(a)(3), to ensure that the Nation takes the
necessary steps to reduce air pollution.

															   The presumption that state agencies are not to
be trusted to do their part is unwarranted in another respect: EPA
itself said so. As EPA concedes, States, by and large, take their
statutory responsibility seriously, and EPA sees no reason to
intervene in the vast majority of cases. Brief for Respondents 30,
n. 9; 57 Fed. Reg. 28095 (1992) (“States have been
largely successful in [‘administering and enforcing the
various components of the PSD program’], and EPA’s
involvement in interpretative and enforcement issues is limited
…”). In light of this concession, EPA and amici not only fail to overcome the established
presumption that States act in good faith, see Alden v. Maine, 527 U. S. 706 , 755 (1999) (“We
are unwilling to assume the States will refuse to honor … or
obey the binding laws of the United States”), but also admit
that their fears about a race to the bottom bear little relation to
the real-world experience under the statute. See ante , at
36 (“We see no reason not to take EPA at its
word”).

															II

															   The statute contains safeguards
to correct arbitrary and capricious BACT decisions when they do
occur. Before EPA approves a State’s PSD permit program that
allows a state agency to make BACT determinations, EPA must be
satisfied that the State provides “an opportunity for state
judicial review.” 61 Fed. Reg. 1882 (1996). Furthermore,
before an individual permit may issue, the State must allow all
“interested persons,” including “representatives
of the [EPA] Administrator,” to submit comments on, among
other things, “control technology requirements.” 42 U.
S. C. §7475(a)(2). To facilitate EPA’s
participation in the State’s public comment process, the
statute further provides that specific procedures be followed to
inform the EPA Administrator of “every action” taken in
the course of the permit approval process. §7475(d)
(“Each State shall transmit to the Administrator a copy of
each permit application relating to a major emitting facility
received by such State and provide notice to the Administrator of
every action related to the consideration of such permit”).
Any person who participated in the comment process can pursue an
administrative appeal of the State’s decision, followed, as
mentioned, by judicial review in state courts.

															   EPA followed none of the normal
procedures here. Only after the period for public comments expired
did it intervene and seek to overturn Alaska’s decision that
Low NOx was BACT. To justify its decision to opt out of the
State’s administrative and judicial review process and,
instead, to issue a unilateral order after everyone had spoken, EPA
complains that it has not before intervened in “any State
administrative review proceedings in State courts” and should
not now be forced to do so. Tr. of Oral Arg. 35. With scant
analysis, the majority agrees. Ante , at 26 (“It
would be unusual, to say the least, for Congress to remit a federal
agency enforcing federal law solely to state court. We decline to
read such an uncommon regime into the Act’s silence”).
The problem, of course, is that it is all the more unusual to allow
a federal agency to take unilateral action to set aside a
State’s administrative decision.

															   Despite EPA’s protestations, the statute
makes explicit provision for EPA to challenge a state
agency’s BACT determination in state proceedings. The statute
requires States to set up an administrative process for
“interested persons” to submit comments.
§7475(a)(2). “[I]nterested persons,” Congress took
care to note, include “representatives of the [EPA]
Administrator.” Ibid.; see also Alaska Stat.
§46.14.990(20) (2002) (defining “person” to
include “an agency of the United States”). Given that
EPA itself requires, as a condition of approving a State’s
PSD program, that this process culminate in judicial review in
state courts, 61 Fed. Reg., at 1882, it follows that EPA, a subset
of all “interested persons,” must take the same
procedural steps and cannot evade the more painstaking state
process by a mere stroke of the pen under the agency’s
letterhead.

															   On a more fundamental level, EPA and the
majority confuse a substantive environmental statute like the CAA
with a general administrative law statute like the Administrative
Procedure Act (APA). EPA, the federal agency charged only with the
CAA’s implementation, has no roving commission to ferret out
arbitrary and capricious conduct by state agencies under the state
equivalent of the APA. That task is left to state courts. See Idaho v. Coeur d’Alene Tribe of Idaho, 521 U. S. 261 ,
276 (1997) (“[T]he elaboration of administrative law …
is one of the primary responsibilities of the state
judiciary”).

															   Like federal courts, state courts are charged
with reviewing agency actions to ensure that they comport with
principles of rationality and due process. See, e.g. , 5 U.
S. C. §706(2)(A); Alaska Stat. §44.62.570(b)(3)
(2002). Counsel for respondents were unable to identify, either in
their briefs or at oral argument, a single State that “does
not have in its law the requirement that its own agencies …
act rationally.” Tr. of Oral Arg. 30. Although it remains an
open question whether EPA can bypass the state judiciary and go
directly into federal district court under 28 U. S. C.
§1345, the availability of state judicial review defeats the
Government’s argument that, absent EPA’s oversight,
there is a legal vacuum where BACT decisions are not subject to
review.

															   Requiring EPA to seek administrative and
judicial review of a State’s BACT determination, instead of
allowing it to be overturned by fiat, avoids the anomaly of
shifting the burden of pleading and of initiating litigation from
EPA to the State. Whether the BACT decision is reviewed in state
court, or in federal district court if that option is available,
see supra , at 8, EPA, as petitioner, bears the initial
burden and costs of filing a petition for review alleging that the
State acted arbitrarily. Under the scheme endorsed by the majority
today, the tables are turned. Once EPA has issued an enforcement
order, and the State seeks to invalidate that order, the State
bears the burden of alleging that EPA acted arbitrarily. EPA and
the majority concede that, because States enjoy substantial
discretion in making BACT determinations, courts reviewing
EPA’s order must ask not simply whether EPA acted arbitrarily
but the convoluted question whether EPA acted arbitrarily in
finding the State acted arbitrarily. Even under this unwieldy
standard of review, and even if the burdens of persuasion and
production remain with EPA, see ante , at 27–28, the
initial burden of pleading and litigation now belongs to the
State.

															   To make its decision more
palatable, the majority holds that EPA still bears the burdens of
production and persuasion, but there is little authority for this.
The Court purports to rely on McCormick on Evidence for the
proposition that “ ‘looking for the burden of
pleading is not a foolproof guide to the allocation of burdens of
proof.’ ” Ante , at 28, n. 17
(quoting 2 J. Strong, McCormick on Evidence §337, pp.
411–412 (5th ed. 1999)). The example—affirmative
defense—discussed in that passage of the treatise, however,
is far afield from the issues raised in this case. In fact, the
treatise instructs that “[i]n most cases, the party who has
the burden of pleading a fact will have the burdens of producing
evidence and of persuading the jury of its existence as
well.” Id., at 411. This is because “[t]he
burdens of pleading and proof with regard to most facts have been
and should be assigned to the plaintiff who generally seeks to
change the present state of affairs and who therefore naturally
should be expected to bear the risk of failure of proof or
persuasion.” Id., at 412. In this case, EPA changed
the status quo ante by issuing an order invalidating
ADEC’s decision. Without upsetting accepted evidentiary
principles, the majority cannot explain why EPA, as respondent in
federal court—as opposed to the State, as petitioner alleging
that EPA’s fait accompli was arbitrary—should
bear the burdens of persuasion and production, or how this unusual
reallocation of burdens should work in practice.

															   In any event, even the majority
accepts that, under its reading of the statute, the State now bears
the burden of pleading. With this burden-shifting benefit alone,
EPA is most unlikely to follow the procedure, prescribed by federal
law, of participating in the State’s administrative process
and seeking judicial review in state courts. Instead, EPA can
simply issue a unilateral order invalidating the State’s BACT
determination and put the burden on the State to challenge
EPA’s order. This end run around the State’s process is
sure to undermine it. Unless Congress was on a fool’s errand,
the loophole the majority finds goes only to demonstrate the
inconsistency between its approach and the statutory scheme.

															   There is a further, and serious, flaw in the
Court’s ruling. Suppose, before EPA issued its orders setting
aside the State’s BACT determination, an Alaska state court
had reviewed the matter and found no error of law or abuse of
discretion in ADEC’s determination. The majority’s
interpretation of the statute would allow EPA to intervene at this
point for the first time, announce that ADEC’s determination
is unreasoned under the CAA, and issue its own orders nullifying
the state court’s ruling. This reworking of the balance
between State and Federal Governments, not to mention the
reallocation of authority between the Executive and Judicial
Branches, shows the implausibility of the majority’s
reasoning.

															   If a federal agency were to exercise an
analogous power to review the decisions of federal courts, the
arrangement would violate the well-established rule that the
judgments of Article III courts cannot be revised by the Executive
or Legislative Branches. See Hayburn’s Case , 2 Dall.
409, 410, n. (1792) (“ ‘[B]y the Constitution,
neither the Secretary [of] War, nor any other Executive officer,
nor even the Legislature, are authorized to sit as a court of
errors on … judicial acts or opinions
…’ ”); see also Plaut v. Spendthrift Farm, Inc., 514 U. S. 211 (1995).
The principle that judicial decisions cannot be reopened at the
whim of the Executive or the Legislature is essential to preserving
separation of powers and judicial independence. Judges cannot,
without sacrificing the autonomy of their office, put onto the
scales of justice some predictive judgment about the probability
that an administrator might reverse their rulings.

															   The Court today denies state judicial systems
the same judicial independence it has long guarded for
itself—only that the injury here is worse. Under the
majority’s holding, decisions by state courts would be
subject to being overturned, not just by any agency, but by an
agency established by a different sovereign. We should be reluctant
to interpret a congressional statute to deny to States the judicial
independence guaranteed by their own constitutions. See Buckalew v. Holloway , 604 P. 2d 240, 245
(Alaska 1979) (“There is no doubt that judicial independence
was a paramount concern of the delegates [to the Alaska
Constitutional Convention]”); see also, e.g., Cal.
Const., Art. III, §3 (“The powers of state government
are legislative, executive, and judicial. Persons charged with the
exercise of one power may not exercise either of the others except
as permitted by this Constitution”); see also 7 B. Witkin,
Summary of California Law 159–160 (9th ed. 1988)
(“[Under] the principle of separation of powers
… , one [department] cannot exercise or interfere with
the functions of either of the others”). The Federal
Government is free, within its vast legislative authority, to
impose federal standards. For States to have a role, however, their
own governing processes must be respected. New York v. United States, 505 U. S. 144 (1992).
If, by some course of reasoning, state courts must live with the
insult that their judgments can be revised by a federal agency, the
Court should at least insist upon a clear instruction from
Congress. That directive cannot be found here. Cf. Gregory v. Ashcroft, 501 U. S. 452 , 460
(1991) (“[I]f Congress intends to alter the usual
constitutional balance between the States and the Federal
Government, it must make its intention to do so unmistakably clear
in the language of the statute” (internal quotation marks
omitted)).

															   There is a final deficiency in the scheme the
majority finds in the statute. Nothing in the Court’s
analysis prevents EPA from issuing an order setting aside a BACT
determination months, or even years, later. Congress cannot have
intended this result. After all, when Congress provides for
EPA’s involvement, it directs the agency to act sooner rather
than later by establishing a pre-authorization procedure. 42 U.
S. C. §7475(a)(8). The majority misses the point when it
faults ADEC for “overlook[ing] the obvious difference between
a statutory requirement … and a statutory
authorization.” Ante , at 25 (emphasis deleted). ADEC
does not overlook the difference between approval before the fact
and oversight after the fact. Rather, ADEC, unlike the majority,
recognizes that the Act’s explicit provision for a
preauthorization process underscores the need for finality in state
permitting decisions, making implausible an interpretation of the
statute that would allow a post hoc veto procedure that
upsets the same reliance and expectation interests.

															   The majority’s initial response that
“[t]his case threatens no such development [because] [i]t
involves preconstruction orders issued by EPA … , not
postconstruction federal Agency directives,” ante, at 29, provides no assurance that the logic of its reasoning would
not in the future allow EPA’s belated interventions. When the
majority confronts the problem, it concludes that “EPA, we
are confident, could not indulge in the inequitable conduct ADEC
and the dissent hypothesize while the federal courts sit to review
EPA’s actions.” Ibid. The authority it cites
for this proposition, however, consists of nothing more than a
religious exemption case that is far removed from the issues
presented here and a dissent from a case that has been overruled in
part. Ibid. State agencies rely on this dictum at their
own risk.

															   The majority’s reassurance to the States
will likely be to no avail. “The principle that the United
States are not bound by any statute of limitations, nor barred by
any laches of their officers, however gross, in a suit brought by
them as a sovereign Government to enforce a public right, or to
assert a public interest, is established past all controversy or
doubt.” United States v. Beebe, 127 U. S. 338 , 344
(1888); see also United States v. Summerlin, 310 U. S. 414 ,
416 (1940) (“It is well settled that the United States is not
bound by state statutes of limitation or subject to the defense of
laches in enforcing its rights”); Utah Power & Light
Co. v. United States, 243 U. S. 389 , 409
(1917) (“[L]aches or neglect of duty on the part of officers
of the Government is no defense to a suit by it to enforce a public
right or protect a public interest … . A suit
by the United States to enforce and maintain its policy …
stands upon a different plane in this and some other respects from
the ordinary private suit …”). Section 167, moreover,
is mandatory. Once a violation of a statutory
“requirement” is found, “[t]he Administrator
shall … take such measures, including issuance of an order,
or seeking injunctive relief, as necessary to prevent the
construction or modification of a major emitting facility which
does not conform to the requirements of this part
… .” 42 U. S. C. §7477. In short,
EPA’s enforcement authority can—indeed, must—be
exercised at any point. In light of our precedents a court would be
hard pressed to hold otherwise.

															   The majority seeks to limit the consequence of
its holding by quoting the response by respondents’ counsel
at oral argument that ADEC could “absolutely” arrive at
the same BACT determination if only it would pile on another layer
of procedure and justify its decision on an
“ ‘appropriate record.’ ” Ante, at 36 (quoting Tr. of Oral Arg. 35). As the Court of
Appeals recognized in a prior case, however, this option gives no
solace to the States:

															“ The hardship is the process itself.
Process costs money. If a federal licensee must spend years
attempting to satisfy an elaborate, shifting array of state
procedural requirements, then he must borrow a fortune to pay
lawyers, economists, accountants, archaeologists, historians,
engineers, recreational consultants, environmental consultants,
biologists and others, with no revenue, no near-term prospect of
revenue, and no certainty that there ever will be revenue.
Meanwhile, politics, laws, interest rates, construction costs, and
costs of alternatives change. Undue process may impose cost and
uncertainty sufficient to thwart the federal determination that a
power project should proceed.” Sayles Hydro
Associates v. Maughan , 985 F. 2d 451, 454 (CA9
1993).

															If there is to be a second look, notwithstanding
the 18 months ADEC spent analyzing BACT, a third or fourth look is
just as permissible. The majority creates a sort of Zeno’s
paradox for state agencies. Because there can always be an
additional procedure to ensure that the preceding process was
followed, no matter how many steps States take toward the
objective, they may never reach it.

															   This is a most regrettable result. In the
proper discharge of their responsibilities to implement the CAA in
different conditions and localities nationwide, the States maintain
permanent staffs within special agencies. These state employees,
who no doubt take pride in their own resourcefulness, expertise,
and commitment to the law, are the officials directed by Congress
to make case-by-case, site-specific, determinations under the Act.
Regulated persons and entities should be able to consult an agency
staff with certainty and confidence, giving due consideration to
agency recommendations and guidance. After today’s decision,
however, a state agency can no longer represent itself as the real
governing body. No matter how much time was spent in consultation
and negotiation, a single federal administrator can in the end set
all aside by a unilateral order. This is a great step backward in
Congress’ design to grant States a significant stake in
developing and enforcing national environmental objectives.

															   If EPA were to announce that permit
applications subject to BACT review must be submitted to it in the
first instance and can be forwarded to the State only with
EPA’s advance approval, I should assume even the majority
would find the basic structure of the BACT provisions undercut. In
practical terms, however, the majority displaces state agencies,
and degrades their role, in much the same way. In the case before
us the applicant made elaborate submissions to ADEC. For over a
year and a half, there ensued the constructive discourse that is
the very object of the agency process, with both the ADEC staff and
the applicant believing the State’s decision would be
dispositive. EPA did not participate in the administrative process,
but waited until after the record was closed to intervene by
issuing an order setting aside the BACT determination.

															   We are advised that an applicant sometimes
must spend up to $500,000 on the permit process and that, for a
complex project, the time for approval can take from five to seven
years. Brief for National Environmental Development Association
et al. as Amici Curiae 8. Under the new
multiple-tiered process, permit expenditures become less justified,
state officials less credible, reliance less certain. The Court
should be under no illusion that its decision respects the
State’s administrative process.

															   The federal balance is remitted, in many
instances, to Congress. Here the Court remits it to a single agency
official. This is inconsistent with the assurance Congress gave to
regulated entities when it allowed state agencies to decide upon
the grant or denial of a permit under the BACT provisions of the
CAA.

															III

															   In the end EPA appears to realize
the weakness of its arguments and asks us simply to defer to its
expertise in light of the purported statutory ambiguity. See Brief
for Respondents 41–43 (asking for deference under Chevron
U. S. A. Inc. v. Natural Resources Defense Council,
Inc., 467 U. S.
837 (1984)). To its credit, the majority holds Chevron deference inapplicable. Deference is inappropriate for all the
reasons the majority recites, ante , at 21–22, plus
one more: The statute is not in any way ambiguous. As a result, our
inquiry should proceed no further.

															   Actions, however, speak louder
than words, and the majority ends up giving EPA the very Chevron deference—and more—it says should be
denied. The Court’s opinion is chock full of Chevron -like language. Compare 467 U. S., at 843
(“whether the agency’s answer is based on a permissible
construction of the statute”); id. , at 845
(“whether the Administrator’s view … is a
reasonable one”), with ante , at 22
(“[EPA’s] arguments do not persuade us to reject [them]
as impermissible”); ante, at 27 (“ That
rational interpretation, we agree, is surely permissible”).
So deficient are its statutory arguments that the majority must
hide behind Chevron ’s vocabulary, despite its
explicit holding that Chevron does not apply. In applying Chevron de facto under these circumstances,
however, the majority undermines the well-established distinction
our precedents draw between Chevron and less deferential
forms of judicial review.

															   The broader implication of today’s
decision is more unfortunate still. The CAA is not the only statute
that relies on a close and equal partnership between federal and
state authorities to accomplish congressional objectives. See, e.g. , New York v. United States, 505 U.
S., at 167 (listing examples). Under the majority’s
reasoning, these other statutes, too, could be said to confer on
federal agencies ultimate decisionmaking authority, relegating
States to the role of mere provinces or political corporations,
instead of coequal sovereigns entitled to the same dignity and
respect. Cf. Alden v. Maine, 527 U. S. 706 (1999). If cooperative
federalism, Hodel v. Virginia Surface Mining &
Reclamation Assn., Inc., 452 U. S. 264 , 289
(1981), is to achieve Congress’ goal of allowing state
governments to be accountable to the democratic process in
implementing environmental policies, federal agencies cannot
consign States to the ministerial tasks of information gathering
and making initial recommendations, while reserving to themselves
the authority to make final judgments under the guise of
surveillance and oversight.

															   For these reasons, and with all respect, I
dissent from the opinion and the judgment of the Court.

Summary: The case concerns the authority of the Environmental Protection Agency (EPA) to enforce the provisions of the Clean Air Act's Prevention of Significant Deterioration (PSD) program, which requires major air pollutant-emitting facilities to be equipped with the best available control technology (BACT) to reduce emissions. The State of Alaska, through its Department of Environmental Conservation (ADEC), is the permitting authority responsible for making BACT determinations. The question is whether the EPA can block the construction of a new major pollutant-emitting facility permitted by ADEC if it finds ADEC's BACT determination unreasonable. The Court holds that the EPA has the authority to do so, ensuring that states comply with the CAA's requirements.