Utility Air Regulatory Group v. EPA

(Slip Opinion) OCTOBER TERM, 2013 1

Syllabus

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is

being done in connection with this case, at the time the opinion is issued.

The syllabus constitutes no part of the opinion of the Court but has been

prepared by the Reporter of Decisions for the convenience of the reader.

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.

SUPREME COURT OF THE UNITED STATES

Syllabus

UTILITY AIR REGULATORY GROUP v.

ENVIRONMENTAL PROTECTION AGENCY ET AL.

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR

THE DISTRICT OF COLUMBIA CIRCUIT

No. 12–1146. Argued February 24, 2014—Decided June 23, 2014 *

The Clean Air Act imposes permitting requirements on stationary

sources, such as factories and powerplants. The Act’s “Prevention of

Significant Deterioration” (PSD) provisions make it unlawful to con-

struct or modify a “major emitting facility” in “any area to which [the

PSD program] applies” without a permit. §§7475(a)(1), 7479(2)(C). A

“major emitting facility” is a stationary source with the potential to

emit 250 tons per year of “any air pollutant” (or 100 tons per year for

certain types of sources). §7479(1). Facilities seeking to qualify for a

PSD permit must, inter alia, comply with emissions limitations that

reflect the “best available control technology” (BACT) for “each pollu-

tant subject to regulation under” the Act. §7475(a)(4). In addition,

Title V of the Act makes it unlawful to operate any “major source,”

wherever located, without a permit. §7661a(a). A “major source” is a

stationary source with the potential to emit 100 tons per year of “any

air pollutant.” §§7661(2)(B), 7602(j).

In response to Massachusetts v. EPA, 549 U. S. 497, EPA promul-

gated greenhouse-gas emission standards for new motor vehicles, and

——————

* Together with No. 12–1248, American Chemistry Council et al. v.

Environmental Protection Agency et al., No. 12–1254, Energy-Intensive

Manufacturers Working Group on Greenhouse Gas Regulation et al. v.

Environmental Protection Agency et al., No. 12–1268, Southeastern Le-

gal Foundation, Inc., et al. v. Environmental Protection Agency et al.,

No. 12–1269, Texas et al. v. Environmental Protection Agency et al., and

No. 12–1272, Chamber of Commerce of United States States et al. v.

Environmental Protection Agency et al., also on certiorari to the same

court.

2 UTILITY AIR REGULATORY GROUP v. EPA

Syllabus

made stationary sources subject to the PSD program and Title V on

the basis of their potential to emit greenhouse gases. It recognized,

however, that requiring permits for all sources with greenhouse-gas

emissions above the statutory thresholds would radically expand

those programs and render them unadministrable. So EPA purport-

ed to “tailor” the programs to accommodate greenhouse gases by

providing, among other things, that sources would not become newly

subject to PSD or Title V permitting on the basis of their potential to

emit greenhouse gases in amounts less than 100,000 tons per year.

Numerous parties, including several States, challenged EPA’s ac-

tions in the D. C. Circuit, which dismissed some of the petitions for

lack of jurisdiction and denied the remainder.

Held: The judgment is affirmed in part and reversed in part.

684 F. 3d 102, affirmed in part and reversed in part.

JUSTICE SCALIA delivered the opinion of the Court with respect to

Parts I and II, concluding:

1. The Act neither compels nor permits EPA to adopt an interpre-

tation of the Act requiring a source to obtain a PSD or Title V permit

on the sole basis of its potential greenhouse-gas emissions. Pp. 10–

24.

(a) The Act does not compel EPA’s interpretation. Massachusetts

held that the Act-wide definition of “air pollutant” includes green-

house gases, 549 U. S., at 529, but where the term “air pollutant” ap-

pears in the Act’s operative provisions, including the PSD and Title V

permitting provisions, EPA has routinely given it a narrower, con-

text-appropriate meaning. Massachusetts did not invalidate those

longstanding constructions. The Act-wide definition is not a com-

mand to regulate, but a description of the universe of substances EPA

may consider regulating under the Act’s operative provisions.

Though Congress’s profligate use of “air pollutant” is not conducive to

clarity, the presumption of consistent usage “ ‘readily yields’ ” to con-

text, and a statutory term “may take on distinct characters from as-

sociation with distinct statutory objects calling for different imple-

mentation strategies.” Environmental Defense v. Duke Energy Corp.,

549 U. S. 561, 574. Pp. 10–16.

(b) Nor does the Act permit EPA’s interpretation. Agencies em-

powered to resolve statutory ambiguities must operate “within the

bounds of reasonable interpretation,” Arlington v. FCC, 569 U. S. ___,

___. EPA has repeatedly acknowledged that applying the PSD and

Title V permitting requirements to greenhouse gases would be incon-

sistent with the Act’s structure and design. A review of the relevant

statutory provisions leaves no doubt that the PSD program and Title

V are designed to apply to, and cannot rationally be extended beyond,

a relative handful of large sources capable of shouldering heavy sub-

Cite as: 573 U. S. ____ (2014) 3

Syllabus

stantive and procedural burdens. EPA’s interpretation would also

bring about an enormous and transformative expansion in EPA’s

regulatory authority without clear congressional authorization. FDA

v. Brown & Williamson Tobacco Corp., 529 U. S. 120, 160. Pp. 16–20.

(c) EPA lacked authority to “tailor” the Act’s unambiguous nu-

merical thresholds of 100 or 250 tons per year to accommodate its

greenhouse-gas-inclusive interpretation of the permitting triggers.

Agencies must always “ ‘give effect to the unambiguously expressed

intent of Congress.’ ” National Assn. of Home Builders v. Defenders

of Wildlife, 551 U. S. 644, 665. The power to execute the laws does

not include a power to revise clear statutory terms that turn out not

to work in practice. Pp. 20–24.

2. EPA reasonably interpreted the Act to require sources that

would need permits based on their emission of conventional pollu-

tants to comply with BACT for greenhouse gases. Pp. 24–29.

(a) Concerns that BACT, which has traditionally been about end-

of-stack controls, is fundamentally unsuited to greenhouse-gas regu-

lation, which is more about energy use, are not unfounded. But an

EPA guidance document states that BACT analysis should consider

options other than energy efficiency, including “carbon capture and

storage,” which EPA contends is reasonably comparable to more tra-

ditional, end-of-stack BACT technologies. Moreover, assuming that

BACT may be used to force improvements in energy efficiency, im-

portant limitations on BACT may work to mitigate concerns about

“unbounded” regulatory authority. Pp. 24–27.

(b) EPA’s decision to require BACT for greenhouse gases emitted

by sources otherwise subject to PSD review is, as a general matter, a

permissible interpretation of the statute under Chevron U. S. A. Inc.

v. Natural Resources Defense Council, Inc., 467 U. S. 837. The specif-

ic phrasing of the BACT provision—which requires BACT “for each

pollutant subject to regulation under” the Act, §7475(a)(4)—does not

suggest that the provision can bear a narrowing construction. And

even if the text were not clear, applying BACT to greenhouse gases is

not so disastrously unworkable, and need not result in such a dra-

matic expansion of agency authority, as to make EPA’s interpretation

unreasonable. Pp. 27–29.

SCALIA, J., announced the judgment of the Court and delivered an

opinion, Parts I and II of which were for the Court. ROBERTS, C. J., and

KENNEDY, J., joined that opinion in full; THOMAS and ALITO, JJ., joined

as to Parts I, II–A, and II–B–1; and GINSBURG, BREYER, SOTOMAYOR,

and KAGAN, JJ., joined as to Part II–B–2. BREYER J., filed an opinion

concurring in part and dissenting in part, in which GINSBURG, SO-

TOMAYOR, and KAGAN, JJ., joined. ALITO, J., filed an opinion concurring

in part and dissenting in part, in which THOMAS, J., joined.

Cite as: 573 U. S. ____ (2014) 1

Opinion of the Court

NOTICE: This opinion is subject to formal revision before publication in the

preliminary print of the United States Reports. Readers are requested to

notify the Reporter of Decisions, Supreme Court of the United States, Wash-

ington, D. C. 20543, of any typographical or other formal errors, in order

that corrections may be made before the preliminary print goes to press.

SUPREME COURT OF THE UNITED STATES

_________________

Nos. 12–1146, 12–1248, 12–1254, 12–1268, 12–1269, and 12–1272

_________________

UTILITY AIR REGULATORY GROUP,

PETITIONER

12–1146 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

AMERICAN CHEMISTRY COUNCIL, ET AL.,

PETITIONERS

12–1248 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

ENERGY-INTENSIVE MANUFACTURERS WORKING

GROUP ON GREENHOUSE GAS REGULATION,

ET AL., PETITIONERS

12–1254 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

SOUTHEASTERN LEGAL FOUNDATION, INC.,

ET AL., PETITIONERS

12–1268 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

TEXAS, ET AL., PETITIONERS

12–1269 v.

ENVIRONMENTAL PROTECTION AGENCY,

ET AL.; AND

2 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

CHAMBER OF COMMERCE OF THE UNITED

STATES, ET AL., PETITIONERS

12–1272 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

ON WRITS OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE DISTRICT OF COLUMBIA CIRCUIT

[June 23, 2014]

JUSTICE SCALIA announced the judgment of the Court

and delivered the opinion of the Court with respect to

Parts I and II.

Acting pursuant to the Clean Air Act, 69 Stat. 322, as

amended, 42 U. S. C. §§7401–7671q, the Environmental

Protection Agency recently set standards for emissions of

“greenhouse gases” (substances it believes contribute to

“global climate change”) from new motor vehicles. We

must decide whether it was permissible for EPA to deter-

mine that its motor-vehicle greenhouse-gas regulations

automatically triggered permitting requirements under

the Act for stationary sources that emit greenhouse gases.

I. Background

A. Stationary-Source Permitting

The Clean Air Act regulates pollution-generating emis-

sions from both stationary sources, such as factories and

powerplants, and moving sources, such as cars, trucks,

and aircraft. This litigation concerns permitting obliga-

tions imposed on stationary sources under Titles I and V

of the Act.

Title I charges EPA with formulating national ambient

air quality standards (NAAQS) for air pollutants. §§7408–

7409. To date, EPA has issued NAAQS for six pollutants:

sulfur dioxide, particulate matter, nitrogen dioxide, carbon

monoxide, ozone, and lead. Clean Air Act Handbook 125

(J. Domike & A. Zacaroli eds., 3d ed. 2011); see generally

40 CFR pt. 50 (2013). States have primary responsibility

Cite as: 573 U. S. ____ (2014) 3

Opinion of the Court

for implementing the NAAQS by developing “State imple-

mentation plans.” 42 U. S. C. §7410. A State must desig-

nate every area within its borders as “attainment,” “non-

attainment,” or “unclassifiable” with respect to each

NAAQS, §7407(d), and the State’s implementation plan

must include permitting programs for stationary sources

that vary according to the classification of the area where

the source is or is proposed to be located. §7410(a)(2)(C),

(I).

Stationary sources in areas designated attainment or

unclassifiable are subject to the Act’s provisions relating to

“Prevention of Significant Deterioration” (PSD). §§7470–

7492. EPA interprets the PSD provisions to apply to

sources located in areas that are designated attainment or

unclassifiable for any NAAQS pollutant, regardless of

whether the source emits that specific pollutant. Since the

inception of the PSD program, every area of the country

has been designated attainment or unclassifiable for at

least one NAAQS pollutant; thus, on EPA’s view, all sta-

tionary sources are potentially subject to PSD review.

It is unlawful to construct or modify a “major emitting

facility” in “any area to which [the PSD program] applies”

without first obtaining a permit. §§7475(a)(1), 7479(2)(C).

To qualify for a permit, the facility must not cause or

contribute to the violation of any applicable air-quality

standard, §7475(a)(3), and it must comply with emissions

limitations that reflect the “best available control technol-

ogy” (or BACT) for “each pollutant subject to regulation

under” the Act. §7475(a)(4). The Act defines a “major

emitting facility” as any stationary source with the poten-

tial to emit 250 tons per year of “any air pollutant” (or 100

tons per year for certain types of sources). §7479(1). It

defines “modification” as a physical or operational change

that causes the facility to emit more of “any air pollutant.”

4 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

§7411(a)(4).1

In addition to the PSD permitting requirements for

construction and modification, Title V of the Act makes it

unlawful to operate any “major source,” wherever located,

without a comprehensive operating permit. §7661a(a).

Unlike the PSD program, Title V generally does not im-

pose any substantive pollution-control requirements.

Instead, it is designed to facilitate compliance and en-

forcement by consolidating into a single document all of a

facility’s obligations under the Act. The permit must

include all “emissions limitations and standards” that

apply to the source, as well as associated inspection, moni-

toring, and reporting requirements. §7661c(a)–(c). Title V

defines a “major source” by reference to the Act-wide

definition of “major stationary source,” which in turn

means any stationary source with the potential to emit

100 tons per year of “any air pollutant.” §§7661(2)(B),

7602( j).

B. EPA’s Greenhouse-Gas Regulations

In 2007, the Court held that Title II of the Act “author-

ize[d] EPA to regulate greenhouse gas emissions from new

motor vehicles” if the Agency “form[ed] a ‘judgment’ that

——————

1 Although the statute sets numerical thresholds (100 or 250 tons per

year) for emissions that will make a facility “major,” it does not specify

by how much a physical or operational change must increase emissions

to constitute a permit-requiring “modification.” Nor does it say how

much of a given regulated pollutant a “major emitting facility” must

emit before it is subject to BACT for that pollutant. EPA, however, has

established pollutant-specific numerical thresholds below which a

facility’s emissions of a pollutant, and increases therein, are considered

de minimis for those purposes. See 40 CFR §§51.166(b)(2)(i), (23), (39),

(j)(2)–(3), 52.21(b)(2)(i), (23), (40), (j)(2)–(3); see also Alabama Power Co.

v. Costle, 636 F. 2d 323, 360–361, 400, 405 (CADC 1979) (recognizing

this authority in EPA); cf. Wisconsin Dept. of Revenue v. William

Wrigley, Jr., Co., 505 U. S. 214, 231 (1992) (“[D]e minimis non curat lex

. . . is part of the established background of legal principles against

which all enactments are adopted”).

Cite as: 573 U. S. ____ (2014) 5

Opinion of the Court

such emissions contribute to climate change.” Massachu­

setts v. EPA, 549 U. S. 497, 528 (quoting §7521(a)(1)). In

response to that decision, EPA embarked on a course of

regulation resulting in “the single largest expansion in the

scope of the [Act] in its history.” Clean Air Act Handbook,

at xxi.

EPA first asked the public, in a notice of proposed rule-

making, to comment on how the Agency should respond to

Massachusetts. In doing so, it explained that regulating

greenhouse-gas emissions from motor vehicles could have

far-reaching consequences for stationary sources. Under

EPA’s view, once greenhouse gases became regulated

under any part of the Act, the PSD and Title V permitting

requirements would apply to all stationary sources with

the potential to emit greenhouse gases in excess of the

statutory thresholds: 100 tons per year under Title V, and

100 or 250 tons per year under the PSD program depend-

ing on the type of source. 73 Fed. Reg. 44420, 44498,

44511 (2008). Because greenhouse-gas emissions tend to

be “orders of magnitude greater” than emissions of con-

ventional pollutants, EPA projected that numerous small

sources not previously regulated under the Act would be

swept into the PSD program and Title V, including “smaller

industrial sources,” “large office and residential build-

ings, hotels, large retail establishments, and similar facili-

ties.” Id., at 44498–44499. The Agency warned that this

would constitute an “unprecedented expansion of EPA

authority that would have a profound effect on virtually

every sector of the economy and touch every household in

the land,” yet still be “relatively ineffective at reducing

greenhouse gas concentrations.” Id., at 44355.2

——————

2 Comments from other Executive Branch agencies reprinted in the

notice echoed those concerns. See, e.g., 73 Fed. Reg. 44360 (Depart-

ments of Agriculture, Commerce, Transportation, and Energy noting

EPA would “exercis[e] de facto zoning authority through control over

thousands of what formerly were local or private decisions, impacting

6 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

In 2009, EPA announced its determination regarding

the danger posed by motor-vehicle greenhouse-gas emis-

sions. EPA found that greenhouse-gas emissions from

new motor vehicles contribute to elevated atmospheric

concentrations of greenhouse gases, which endanger pub-

lic health and welfare by fostering global “climate change.”

74 Fed. Reg. 66523, 66537 (hereinafter Endangerment

Finding). It denominated a “single air pollutant” the

“combined mix” of six greenhouse gases that it identified

as “the root cause of human-induced climate change”:

carbon dioxide, methane, nitrous oxide, hydrofluorocar-

bons, perfluorocarbons, and sulfur hexafluoride. Id., at

66516, 66537. A source’s greenhouse-gas emissions would

be measured in “carbon dioxide equivalent units” (CO2e),

which would be calculated based on each gas’s “global

warming potential.” Id., at 66499, n. 4.

Next, EPA issued its “final decision” regarding the

prospect that motor-vehicle greenhouse-gas standards

would trigger stationary-source permitting requirements.

75 Fed. Reg. 17004 (2010) (hereinafter Triggering Rule).

EPA announced that beginning on the effective date of its

greenhouse-gas standards for motor vehicles, stationary

sources would be subject to the PSD program and Title V

on the basis of their potential to emit greenhouse gases.

As expected, EPA in short order promulgated greenhouse-

gas emission standards for passenger cars, light-duty

——————

the construction of schools, hospitals, and commercial and residential

development”); id., at 44383 (Council of Economic Advisers and Office

of Science and Technology Policy stating that “[s]mall manufacturing

facilities, schools, and shopping centers” would be subject to “full major

source permitting”); id., at 44385 (Council on Environmental Quality

noting “the prospect of essentially automatic and immediate regulation

over a vast range of community and business activity”); id., at 44391

(Small Business Administration finding it “difficult to overemphasize

how potentially disruptive and burdensome such a new regulatory

regime would be to small entities” such as “office buildings, retail

establishments, hotels, . . . schools, prisons, and private hospitals”).

Cite as: 573 U. S. ____ (2014) 7

Opinion of the Court

trucks, and medium-duty passenger vehicles to take effect

on January 2, 2011. 75 Fed. Reg. 25324 (hereinafter

Tailpipe Rule).

EPA then announced steps it was taking to “tailor” the

PSD program and Title V to greenhouse gases. 75 Fed.

Reg. 31514 (hereinafter Tailoring Rule). Those steps were

necessary, it said, because the PSD program and Title V

were designed to regulate “a relatively small number of

large industrial sources,” and requiring permits for all

sources with greenhouse-gas emissions above the statu-

tory thresholds would radically expand those programs,

making them both unadministrable and “unrecognizable

to the Congress that designed” them. Id., at 31555, 31562.

EPA nonetheless rejected calls to exclude greenhouse

gases entirely from those programs, asserting that the Act

is not “ambiguous with respect to the need to cover

[greenhouse-gas] sources under either the PSD or title V

program.” Id., at 31548, n. 31. Instead, EPA adopted a

“phase-in approach” that it said would “appl[y] PSD and

title V at threshold levels that are as close to the statutory

levels as possible, and do so as quickly as possible, at least

to a certain point.” Id., at 31523.

The phase-in, EPA said, would consist of at least three

steps. During Step 1, from January 2 through June 30,

2011, no source would become newly subject to the PSD

program or Title V solely on the basis of its greenhouse-

gas emissions; however, sources required to obtain permits

anyway because of their emission of conventional pollu-

tants (so-called “anyway” sources) would need to comply

with BACT for greenhouse gases if they emitted those

gases in significant amounts, defined as at least 75,000

tons per year CO2e. Ibid. During Step 2, from July 1,

2011, through June 30, 2012, sources with the potential to

emit at least 100,000 tons per year CO2e of greenhouse

gases would be subject to PSD and Title V permitting for

their construction and operation and to PSD permitting

8 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

for modifications that would increase their greenhouse-gas

emissions by at least 75,000 tons per year CO2e. Id., at

31523–31524.3 At Step 3, beginning on July 1, 2013, EPA

said it might (or might not) further reduce the permitting

thresholds (though not below 50,000 tons per year CO2e),

and it might (or might not) establish permanent exemp-

tions for some sources. Id., at 31524. Beyond Step 3, EPA

promised to complete another round of rulemaking by

April 30, 2016, in which it would “take further action to

address small sources,” which might (or might not) include

establishing permanent exemptions. Id., at 31525.

EPA codified Steps 1 and 2 at 40 CFR §§51.166(b)(48)

and 52.21(b)(49) for PSD and at §§70.2 and 71.2 for Title

V, and it codified its commitments regarding Step 3 and

beyond at §§52.22, 70.12, and 71.13. See Tailoring Rule

31606–31608. After the decision below, EPA issued its

final Step 3 rule, in which it decided not to lower the

thresholds it had established at Step 2 until at least 2016.

77 Fed. Reg. 41051 (2012).

C. Decision Below

Numerous parties, including several States, filed peti-

tions for review in the D. C. Circuit under 42 U. S. C.

§7607(b), challenging EPA’s greenhouse-gas-related ac-

tions. The Court of Appeals dismissed some of the peti-

tions for lack of jurisdiction and denied the remainder.

Coalition for Responsible Regulation, Inc. v. EPA, 684

F. 3d 102 (2012) (per curiam). First, it upheld the Endan-

germent Finding and Tailpipe Rule. Id., at 119, 126.

Next, it held that EPA’s interpretation of the PSD permit-

ting requirement as applying to “any regulated air pollu-

——————

3 EPA stated that its adoption of a 75,000-tons-per-year threshold for

emissions requiring BACT and modifications requiring permits was not

an exercise of its authority to establish de minimis exceptions and that

a truly de minimis level might be “well below” 75,000 tons per year.

Tailoring Rule 31560; cf. n. 1, supra.

Cite as: 573 U. S. ____ (2014) 9

Opinion of the Court

tant,” including greenhouse gases, was “compelled by the

statute.” Id., at 133–134. The court also found it “crystal

clear that PSD permittees must install BACT for green-

house gases.” Id., at 137. Because it deemed petitioners’

arguments about the PSD program insufficiently applica-

ble to Title V, it held they had “forfeited any challenges to

EPA’s greenhouse gas-inclusive interpretation of Title V.”

Id., at 136. Finally, it held that petitioners were without

Article III standing to challenge EPA’s efforts to limit the

reach of the PSD program and Title V through the Trig-

gering and Tailoring Rules. Id., at 146. The court denied

rehearing en banc, with Judges Brown and Kavanaugh

each dissenting. No. 09–1322 etc. (Dec. 20, 2012), App.

139, 2012 WL 6621785.

We granted six petitions for certiorari but agreed to

decide only one question: “ ‘Whether EPA permissibly

determined that its regulation of greenhouse gas emis-

sions from new motor vehicles triggered permitting re-

quirements under the Clean Air Act for stationary sources

that emit greenhouse gases.’ ” 571 U. S. ____ (2013).

II. Analysis

This litigation presents two distinct challenges to EPA’s

stance on greenhouse-gas permitting for stationary

sources. First, we must decide whether EPA permissibly

determined that a source may be subject to the PSD and

Title V permitting requirements on the sole basis of the

source’s potential to emit greenhouse gases. Second, we

must decide whether EPA permissibly determined that a

source already subject to the PSD program because of its

emission of conventional pollutants (an “anyway” source)

may be required to limit its greenhouse-gas emissions by

employing the “best available control technology” for

greenhouse gases. The Solicitor General joins issue on

both points but evidently regards the second as more

important; he informs us that “anyway” sources account

10 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

for roughly 83% of American stationary-source greenhouse-

gas emissions, compared to just 3% for the additional, non-

“anyway” sources EPA sought to regulate at Steps 2 and 3

of the Tailoring Rule. Tr. of Oral Arg. 52.

We review EPA’s interpretations of the Clean Air Act

using the standard set forth in Chevron U. S. A. Inc. v.

Natural Resources Defense Council, Inc., 467 U. S. 837,

842–843 (1984). Under Chevron, we presume that when

an agency-administered statute is ambiguous with respect

to what it prescribes, Congress has empowered the agency

to resolve the ambiguity. The question for a reviewing

court is whether in doing so the agency has acted reasona-

bly and thus has “stayed within the bounds of its statutory

authority.” Arlington v. FCC, 569 U. S. ___, ___ (2013)

(slip op., at 5) (emphasis deleted).

A. The PSD and Title V Triggers

We first decide whether EPA permissibly interpreted

the statute to provide that a source may be required to

obtain a PSD or Title V permit on the sole basis of its

potential greenhouse-gas emissions.

1

EPA thought its conclusion that a source’s greenhouse-

gas emissions may necessitate a PSD or Title V permit

followed from the Act’s unambiguous language. The Court

of Appeals agreed and held that the statute “compelled”

EPA’s interpretation. 684 F. 3d, at 134. We disagree.

The statute compelled EPA’s greenhouse-gas-inclusive

interpretation with respect to neither the PSD program

nor Title V.4

——————

4 The Court of Appeals held that petitioners’ arguments applied only

to the PSD program and that petitioners had therefore “forfeited any

challenges to EPA’s greenhouse gas-inclusive interpretation of Title V.”

684 F. 3d, at 136. The Solicitor General does not defend the Court of

Appeals’ ruling on forfeiture, and he concedes that some of the argu-

Cite as: 573 U. S. ____ (2014) 11

Opinion of the Court

The Court of Appeals reasoned by way of a flawed syllo-

gism: Under Massachusetts, the general, Act-wide defini-

tion of “air pollutant” includes greenhouse gases; the Act

requires permits for major emitters of “any air pollutant”;

therefore, the Act requires permits for major emitters of

greenhouse gases. The conclusion follows from the prem-

ises only if the air pollutants referred to in the permit-

requiring provisions (the minor premise) are the same air

pollutants encompassed by the Act-wide definition as

interpreted in Massachusetts (the major premise). Yet no

one—least of all EPA—endorses that proposition, and it is

obviously untenable.

The Act-wide definition says that an air pollutant is

“any air pollution agent or combination of such agents,

including any physical, chemical, biological, [or] radioac-

tive . . . substance or matter which is emitted into or oth-

erwise enters the ambient air.” §7602(g). In Massachu­

setts, the Court held that the Act-wide definition includes

greenhouse gases because it is all-encompassing; it “em-

braces all airborne compounds of whatever stripe.” 549

U. S., at 529. But where the term “air pollutant” appears

in the Act’s operative provisions, EPA has routinely given

it a narrower, context-appropriate meaning.

That is certainly true of the provisions that require PSD

and Title V permitting for major emitters of “any air pollu-

tant.” Since 1978, EPA’s regulations have interpreted “air

pollutant” in the PSD permitting trigger as limited to

regulated air pollutants, 43 Fed. Reg. 26403, codified, as

amended, 40 CFR §52.21(b)(1)–(2), (50)—a class much

narrower than Massachusetts’ “all airborne compounds of

——————

ments petitioners have made before this Court apply to Title V as well

as the PSD program. See Brief for Federal Respondents 56. We agree,

and we are satisfied that those arguments were also made below. See,

e.g., Brief for State Petitioners et al. in No. 10–1073 etc. (CADC), pp.

59–73; Brief for Non-State Petitioners et al. in No. 10–1073 etc.

(CADC), pp. 46–47.

12 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

whatever stripe,” 549 U. S., at 529. And since 1993 EPA

has informally taken the same position with regard to the

Title V permitting trigger, a position the Agency ultimately

incorporated into some of the regulations at issue here.

See Memorandum from Lydia N. Wegman, Deputy Direc-

tor, Office of Air Quality Planning and Standards, to Air

Division Director, Regions I–X, pp. 4–5 (Apr. 26, 1993);

Tailoring Rule 31607–31608 (amending 40 CFR §§70.2,

71.2). Those interpretations were appropriate: It is plain

as day that the Act does not envision an elaborate, bur-

densome permitting process for major emitters of steam,

oxygen, or other harmless airborne substances. It takes

some cheek for EPA to insist that it cannot possibly give

“air pollutant” a reasonable, context-appropriate meaning

in the PSD and Title V contexts when it has been doing

precisely that for decades.

Nor are those the only places in the Act where EPA has

inferred from statutory context that a generic reference to

air pollutants does not encompass every substance falling

within the Act-wide definition. Other examples abound:

 The Act authorizes EPA to enforce new source per-

formance standards (NSPS) against a pre-existing

source if, after promulgation of the standards, the

source undergoes a physical or operational change

that increases its emission of “any air pollutant.”

§7411(a)(2), (4), (b)(1)(B). EPA interprets that pro-

vision as limited to air pollutants for which EPA

has promulgated new source performance stand­

ards. 36 Fed. Reg. 24877 (1971), codified, as

amended, 40 CFR §60.2; 40 Fed. Reg. 58419 (1975),

codified, as amended, 40 CFR §60.14(a).

 The Act requires a permit for the construction or

operation in a nonattainment area of a source with

the potential to emit 100 tons per year of “any air

Cite as: 573 U. S. ____ (2014) 13

Opinion of the Court

pollutant.” §§7502(c)(5), 7602(j). EPA interprets

that provision as limited to pollutants for which the

area is designated nonattainment. 45 Fed. Reg.

52745 (1980), promulgating 40 CFR §51.18(j)(2), as

amended, §51.165(a)(2).

 The Act directs EPA to require “enhanced monitor-

ing and submission of compliance certifications” for

any source with the potential to emit 100 tons per

year of “any air pollutant.” §§7414(a)(3), 7602(j).

EPA interprets that provision as limited to regulated

pollutants. 62 Fed. Reg. 54941 (1997), codified

at 40 CFR §§64.1, 64.2.

 The Act requires certain sources of air pollutants

that interfere with visibility to undergo retrofitting

if they have the potential to emit 250 tons per year

of “any pollutant.” §7491(b)(2)(A), (g)(7). EPA in-

terprets that provision as limited to visibility­

impairing air pollutants. 70 Fed. Reg. 39160

(2005), codified at 40 CFR pt. 51, App. Y, §II.A.3.

Although these limitations are nowhere to be found in the

Act-wide definition, in each instance EPA has concluded—

as it has in the PSD and Title V context—that the statute

is not using “air pollutant” in Massachusetts’ broad sense

to mean any airborne substance whatsoever.

Massachusetts did not invalidate all these longstanding

constructions. That case did not hold that EPA must

always regulate greenhouse gases as an “air pollutant”

everywhere that term appears in the statute, but only that

EPA must “ground its reasons for action or inaction in the

statute,” 549 U. S., at 535 (emphasis added), rather than

on “reasoning divorced from the statutory text,” id., at

532. EPA’s inaction with regard to Title II was not suffi-

ciently grounded in the statute, the Court said, in part

14 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

because nothing in the Act suggested that regulating

greenhouse gases under that Title would conflict with the

statutory design. Title II would not compel EPA to regu-

late in any way that would be “extreme,” “counterintui-

tive,” or contrary to “ ‘common sense.’ ” Id., at 531. At

most, it would require EPA to take the modest step of

adding greenhouse-gas standards to the roster of new-

motor-vehicle emission regulations. Ibid.

Massachusetts does not strip EPA of authority to ex-

clude greenhouse gases from the class of regulable air

pollutants under other parts of the Act where their inclu-

sion would be inconsistent with the statutory scheme. The

Act-wide definition to which the Court gave a “sweeping”

and “capacious” interpretation, id., at 528, 532, is not a

command to regulate, but a description of the universe of

substances EPA may consider regulating under the Act’s

operative provisions. Massachusetts does not foreclose the

Agency’s use of statutory context to infer that certain of

the Act’s provisions use “air pollutant” to denote not every

conceivable airborne substance, but only those that may

sensibly be encompassed within the particular regulatory

program. As certain amici felicitously put it, while Mas­

sachusetts “rejected EPA’s categorical contention that

greenhouse gases could not be ‘air pollutants’ for any

purposes of the Act,” it did not “embrace EPA’s current,

equally categorical position that greenhouse gases must be

air pollutants for all purposes” regardless of the statutory

context. Brief for Administrative Law Professors et al. as

Amici Curiae 17.5

——————

5 Our decision in American Elec. Power Co. v. Connecticut, 564 U. S.

___ (2011), does not suggest otherwise. We there held that the Act’s

authorization for EPA to establish performance standards for power-

plant greenhouse-gas emissions displaced any federal-common-law

right that might otherwise have existed to seek abatement of those

emissions. Id., at ___ (slip op., at 10). The authorization to which we

referred was that given in the NSPS program of §7411, a part of the Act

Cite as: 573 U. S. ____ (2014) 15

Opinion of the Court

To be sure, Congress’s profligate use of “air pollutant”

where what is meant is obviously narrower than the Act-

wide definition is not conducive to clarity. One ordinarily

assumes “ ‘that identical words used in different parts of

the same act are intended to have the same meaning.’ ”

Environmental Defense v. Duke Energy Corp., 549 U. S.

561, 574 (2007). In this respect (as in countless others),

the Act is far from a chef d’oeuvre of legislative draftsman-

ship. But we, and EPA, must do our best, bearing in mind

the “ ‘fundamental canon of statutory construction that the

words of a statute must be read in their context and with a

view to their place in the overall statutory scheme.’ ” FDA

v. Brown & Williamson Tobacco Corp., 529 U. S. 120, 133

(2000). As we reiterated the same day we decided Massa­

chusetts, the presumption of consistent usage “ ‘readily

yields’ ” to context, and a statutory term—even one defined

in the statute—“may take on distinct characters from

association with distinct statutory objects calling for dif-

ferent implementation strategies.” Duke Energy, supra, at

574.

We need not, and do not, pass on the validity of all the

limiting constructions EPA has given the term “air pollu-

tant” throughout the Act. We merely observe that taken

together, they belie EPA’s rigid insistence that when

interpreting the PSD and Title V permitting requirements

it is bound by the Act-wide definition’s inclusion of green-

house gases, no matter how incompatible that inclusion is

with those programs’ regulatory structure.

In sum, there is no insuperable textual barrier to EPA’s

interpreting “any air pollutant” in the permitting triggers

of PSD and Title V to encompass only pollutants emitted

in quantities that enable them to be sensibly regulated at

the statutory thresholds, and to exclude those atypical

——————

not at issue here and one that no party in American Electric Power

argued was ill suited to accommodating greenhouse gases.

16 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

pollutants that, like greenhouse gases, are emitted in such

vast quantities that their inclusion would radically trans-

form those programs and render them unworkable as

written.6

2

Having determined that EPA was mistaken in thinking

the Act compelled a greenhouse-gas-inclusive interpreta-

tion of the PSD and Title V triggers, we next consider the

Agency’s alternative position that its interpretation was

justified as an exercise of its “discretion” to adopt “a rea-

sonable construction of the statute.” Tailoring Rule 31517.

We conclude that EPA’s interpretation is not permissible.

Even under Chevron’s deferential framework, agencies

must operate “within the bounds of reasonable interpreta-

tion.” Arlington, 569 U. S., at ___ (slip op., at 5). And

reasonable statutory interpretation must account for both

“the specific context in which . . . language is used” and

“the broader context of the statute as a whole.” Robinson

v. Shell Oil Co., 519 U. S. 337, 341 (1997). A statutory

——————

6 During the course of this litigation, several possible limiting con-

structions for the PSD trigger have been proposed. Judge Kavanaugh

argued below that it would be plausible for EPA to read “any air pollu-

tant” in the PSD context as limited to the six NAAQS pollutants. See

Coalition for Responsible Regulation, Inc. v. EPA, No. 09–1322 etc.

(CADC, Dec. 20, 2012), App. 171–180, 2012 WL 6621785, *15–*18

(opinion dissenting from denial of rehearing en banc). Some petitioners

make a slightly different argument: that because PSD permitting is

required only for major emitting facilities “in any area to which [the

PSD program] applies,” §7475(a), the relevant pollutants are only those

NAAQS pollutants for which the area in question is designated attain-

ment or unclassifiable. That approach would bring EPA’s interpreta-

tion of the PSD trigger in line with its longstanding interpretation of

the permitting requirements for nonattainment areas. Others main-

tain that “any air pollutant” in the PSD provision should be limited to

air pollutants with localized effects on air quality. We do not foreclose

EPA or the courts from considering those constructions in the future,

but we need not do so today.

Cite as: 573 U. S. ____ (2014) 17

Opinion of the Court

“provision that may seem ambiguous in isolation is often

clarified by the remainder of the statutory scheme . . .

because only one of the permissible meanings produces a

substantive effect that is compatible with the rest of the

law.” United Sav. Assn. of Tex. v. Timbers of Inwood

Forest Associates, Ltd., 484 U. S. 365, 371 (1988). Thus,

an agency interpretation that is “inconsisten[t] with the

design and structure of the statute as a whole,” University

of Tex. Southwestern Medical Center v. Nassar, 570 U. S.

___, ___ (2013) (slip op., at 13), does not merit deference.

EPA itself has repeatedly acknowledged that applying

the PSD and Title V permitting requirements to green-

house gases would be inconsistent with—in fact, would

overthrow—the Act’s structure and design. In the Tailor-

ing Rule, EPA described the calamitous consequences of

interpreting the Act in that way. Under the PSD program,

annual permit applications would jump from about 800 to

nearly 82,000; annual administrative costs would swell

from $12 million to over $1.5 billion; and decade-long

delays in issuing permits would become common, causing

construction projects to grind to a halt nationwide. Tailor-

ing Rule 31557. The picture under Title V was equally

bleak: The number of sources required to have permits

would jump from fewer than 15,000 to about 6.1 million;

annual administrative costs would balloon from $62 mil-

lion to $21 billion; and collectively the newly covered

sources would face permitting costs of $147 billion. Id., at

31562–31563. Moreover, “the great majority of additional

sources brought into the PSD and title V programs would

be small sources that Congress did not expect would need

to undergo permitting.” Id., at 31533. EPA stated that

these results would be so “contrary to congressional in-

tent,” and would so “severely undermine what Congress

sought to accomplish,” that they necessitated as much as a

1,000-fold increase in the permitting thresholds set forth

in the statute. Id., at 31554, 31562.

18 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

Like EPA, we think it beyond reasonable debate that

requiring permits for sources based solely on their emis-

sion of greenhouse gases at the 100- and 250-tons-per-year

levels set forth in the statute would be “incompatible” with

“the substance of Congress’ regulatory scheme.” Brown &

Williamson, 529 U. S., at 156. A brief review of the rele-

vant statutory provisions leaves no doubt that the PSD

program and Title V are designed to apply to, and cannot

rationally be extended beyond, a relative handful of large

sources capable of shouldering heavy substantive and

procedural burdens.

Start with the PSD program, which imposes numerous

and costly requirements on those sources that are required

to apply for permits. Among other things, the applicant

must make available a detailed scientific analysis of the

source’s potential pollution-related impacts, demonstrate

that the source will not contribute to the violation of any

applicable pollution standard, and identify and use the

“best available control technology” for each regulated

pollutant it emits. §7475(a)(3), (4), (6), (e). The permitting

authority (the State, usually) also bears its share of the

burden: It must grant or deny a permit within a year,

during which time it must hold a public hearing on the

application. §7475(a)(2), (c). Not surprisingly, EPA

acknowledges that PSD review is a “complicated, resource-

intensive, time-consuming, and sometimes contentious

process” suitable for “hundreds of larger sources,” not

“tens of thousands of smaller sources.” 74 Fed. Reg.

55304, 55321–55322.

Title V contains no comparable substantive require-

ments but imposes elaborate procedural mandates. It

requires the applicant to submit, within a year of becom-

ing subject to Title V, a permit application and a “compli-

ance plan” describing how it will comply with “all applica-

ble requirements” under the Act; to certify its compliance

annually; and to submit to “inspection, entry, monitoring,

Cite as: 573 U. S. ____ (2014) 19

Opinion of the Court

. . . and reporting requirements.” §§7661b(b)–(c),

7661c(a)–(c). The procedural burdens on the permitting

authority and EPA are also significant. The permitting

authority must hold a public hearing on the application,

§7661a(b)(6), and it must forward the application and any

proposed permit to EPA and neighboring States and re-

spond in writing to their comments, §7661d(a), (b)(1). If it

fails to issue or deny the permit within 18 months, any

interested party can sue to require a decision “without

additional delay.” §§7661a(b)(7), 7661b(c). An interested

party also can petition EPA to block issuance of the per-

mit; EPA must grant or deny the petition within 60 days,

and its decision may be challenged in federal court.

§7661d(b)(2)–(3). As EPA wrote, Title V is “finely crafted

for thousands,” not millions, of sources. Tailoring Rule

31563.

The fact that EPA’s greenhouse-gas-inclusive interpre-

tation of the PSD and Title V triggers would place plainly

excessive demands on limited governmental resources is

alone a good reason for rejecting it; but that is not the only

reason. EPA’s interpretation is also unreasonable because

it would bring about an enormous and transformative

expansion in EPA’s regulatory authority without clear

congressional authorization. When an agency claims to

discover in a long-extant statute an unheralded power to

regulate “a significant portion of the American economy,”

Brown & Williamson, 529 U. S., at 159, we typically greet

its announcement with a measure of skepticism. We

expect Congress to speak clearly if it wishes to assign to

an agency decisions of vast “economic and political signifi-

cance.” Id., at 160; see also MCI Telecommunications

Corp. v. American Telephone & Telegraph Co., 512 U. S.

218, 231 (1994); Industrial Union Dept., AFL–CIO v.

American Petroleum Institute, 448 U. S. 607, 645–646

(1980) (plurality opinion). The power to require permits

for the construction and modification of tens of thousands,

20 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

and the operation of millions, of small sources nationwide

falls comfortably within the class of authorizations that we

have been reluctant to read into ambiguous statutory text.

Moreover, in EPA’s assertion of that authority, we con-

front a singular situation: an agency laying claim to ex-

travagant statutory power over the national economy

while at the same time strenuously asserting that the

authority claimed would render the statute “unrecogniza-

ble to the Congress that designed” it. Tailoring Rule

31555. Since, as we hold above, the statute does not com-

pel EPA’s interpretation, it would be patently unreason-

able—not to say outrageous—for EPA to insist on seizing

expansive power that it admits the statute is not designed

to grant.7

3

EPA thought that despite the foregoing problems, it

could make its interpretation reasonable by adjusting the

levels at which a source’s greenhouse-gas emissions would

——————

7 A few additional points bear mentioning. The Solicitor General

conjectures that EPA might eventually alter its longstanding interpre-

tation of “potential to emit” in order to reduce the number of sources

required to have permits at the statutory thresholds. But neither he

nor the Agency has given us any reason to believe that there exists a

plausible reading of “potential to emit” that EPA would willingly adopt

and that would eliminate the unreasonableness of EPA’s interpretation.

Nor have we been given any information about the ability of other

possible “streamlining” techniques alluded to by EPA—such as “gen-

eral” or “electronic” permitting—to reduce the administrability prob-

lems identified above; and in any event, none of those techniques would

address the more fundamental problem of EPA’s claiming regulatory

authority over millions of small entities that it acknowledges the Act

does not seek to regulate. Finally, the Solicitor General suggests that

the incompatibility of greenhouse gases with the PSD program and

Title V results chiefly from the inclusion of carbon dioxide in the

“aggregate pollutant” defined by EPA. We decide these cases on the

basis of the pollutant “greenhouse gases” as EPA has defined and

regulated it, and we express no view on how our analysis might change

were EPA to define it differently.

Cite as: 573 U. S. ____ (2014) 21

Opinion of the Court

oblige it to undergo PSD and Title V permitting. Although

the Act, in no uncertain terms, requires permits for

sources with the potential to emit more than 100 or 250

tons per year of a relevant pollutant, EPA in its Tailoring

Rule wrote a new threshold of 100,000 tons per year for

greenhouse gases. Since the Court of Appeals thought the

statute unambiguously made greenhouse gases capable of

triggering PSD and Title V, it held that petitioners lacked

Article III standing to challenge the Tailoring Rule be-

cause that rule did not injure petitioners but merely re-

laxed the pre-existing statutory requirements. Because

we, however, hold that EPA’s greenhouse-gas-inclusive

interpretation of the triggers was not compelled, and

because EPA has essentially admitted that its interpreta-

tion would be unreasonable without “tailoring,” we consider

the validity of the Tailoring Rule.

We conclude that EPA’s rewriting of the statutory

thresholds was impermissible and therefore could not

validate the Agency’s interpretation of the triggering

provisions. An agency has no power to “tailor” legislation

to bureaucratic policy goals by rewriting unambiguous

statutory terms. Agencies exercise discretion only in the

interstices created by statutory silence or ambiguity; they

must always “ ‘give effect to the unambiguously expressed

intent of Congress.’ ” National Assn. of Home Builders v.

Defenders of Wildlife, 551 U. S. 644, 665 (2007) (quoting

Chevron, 467 U. S., at 843). It is hard to imagine a statu-

tory term less ambiguous than the precise numerical

thresholds at which the Act requires PSD and Title V

permitting. When EPA replaced those numbers with

others of its own choosing, it went well beyond the “bounds

of its statutory authority.” Arlington, 569 U. S., at ___

(slip op., at 5) (emphasis deleted).

The Solicitor General does not, and cannot, defend the

Tailoring Rule as an exercise of EPA’s enforcement discre-

tion. The Tailoring Rule is not just an announcement of

22 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

EPA’s refusal to enforce the statutory permitting require-

ments; it purports to alter those requirements and to

establish with the force of law that otherwise-prohibited

conduct will not violate the Act. This alteration of the

statutory requirements was crucial to EPA’s “tailoring”

efforts. Without it, small entities with the potential to

emit greenhouse gases in amounts exceeding the statutory

thresholds would have remained subject to citizen suits—

authorized by the Act—to enjoin their construction, modi-

fication, or operation and to impose civil penalties of up to

$37,500 per day of violation. §§7413(b), 7604(a), (f)(4); 40

CFR §19.4. EPA itself has recently affirmed that the

“independent enforcement authority” furnished by the

citizen-suit provision cannot be displaced by a permitting

authority’s decision not to pursue enforcement. 78 Fed.

Reg. 12477, 12486–12487 (2013). The Solicitor General is

therefore quite right to acknowledge that the availability

of citizen suits made it necessary for EPA, in seeking

to mitigate the unreasonableness of its greenhouse-gas-

inclusive interpretation, to go beyond merely exercising its

enforcement discretion. See Tr. of Oral Arg. 87–88.

For similar reasons, Morton v. Ruiz, 415 U. S. 199

(1974)—to which the Solicitor General points as the best

case supporting the Tailoring Rule, see Tr. of Oral Arg. 71,

80–81—is irrelevant. In Ruiz, Congress had appropriated

funds for the Bureau of Indian Affairs to spend on provid-

ing assistance to “ ‘Indians throughout the United States’ ”

and had not “impose[d] any geographical limitation on the

availability of general assistance benefits.” Id., at 206–

207, and n. 7. Although we held the Bureau could not

deny benefits to off-reservation Indians because it had not

published its eligibility criteria, we stated in dictum that

the Bureau could, if it followed proper administrative

procedures, “create reasonable classifications and eligibil-

ity requirements in order to allocate the limited funds

available.” Id., at 230–231. That dictum stands only for

Cite as: 573 U. S. ____ (2014) 23

Opinion of the Court

the unremarkable proposition that an agency may adopt

policies to prioritize its expenditures within the bounds

established by Congress. See also Lincoln v. Vigil, 508

U. S. 182, 192–193 (1993). Nothing in Ruiz remotely

authorizes an agency to modify unambiguous require-

ments imposed by a federal statute. An agency confront-

ing resource constraints may change its own conduct, but

it cannot change the law.

Were we to recognize the authority claimed by EPA in

the Tailoring Rule, we would deal a severe blow to the

Constitution’s separation of powers. Under our system of

government, Congress makes laws and the President,

acting at times through agencies like EPA, “faithfully

execute[s]” them. U. S. Const., Art. II, §3; see Medellín v.

Texas, 552 U. S. 491, 526–527 (2008). The power of exe-

cuting the laws necessarily includes both authority and

responsibility to resolve some questions left open by Con-

gress that arise during the law’s administration. But it

does not include a power to revise clear statutory terms

that turn out not to work in practice. See, e.g., Barnhart

v. Sigmon Coal Co., 534 U. S. 438, 462 (2002) (agency

lacked authority “to develop new guidelines or to assign

liability in a manner inconsistent with” an “unambiguous

statute”).

In the Tailoring Rule, EPA asserts newfound authority

to regulate millions of small sources—including retail

stores, offices, apartment buildings, shopping centers,

schools, and churches—and to decide, on an ongoing basis

and without regard for the thresholds prescribed by Con-

gress, how many of those sources to regulate. We are not

willing to stand on the dock and wave goodbye as EPA

embarks on this multiyear voyage of discovery. We reaf-

firm the core administrative-law principle that an agency

may not rewrite clear statutory terms to suit its own sense

of how the statute should operate. EPA therefore lacked

authority to “tailor” the Act’s unambiguous numerical

24 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

thresholds to accommodate its greenhouse-gas-inclusive

interpretation of the permitting triggers. Instead, the

need to rewrite clear provisions of the statute should have

alerted EPA that it had taken a wrong interpretive turn.

Agencies are not free to “adopt . . . unreasonable interpre-

tations of statutory provisions and then edit other statu-

tory provisions to mitigate the unreasonableness.” App. 175,

2012 WL 6621785, *16 (Kavanaugh, J., dissenting from

denial of rehearing en banc). Because the Tailoring Rule

cannot save EPA’s interpretation of the triggers, that

interpretation was impermissible under Chevron.8

B. BACT for “Anyway” Sources

For the reasons we have given, EPA overstepped its

statutory authority when it decided that a source could

——————

8 JUSTICE BREYER argues, post, at 10 (opinion concurring in part and

dissenting in part), that when the statutory permitting thresholds of

100 or 250 tons per year do not provide a “sensible regulatory line,”

EPA is entitled to “read an unwritten exception” into “the particular

number used by the statute”—by which he apparently means that the

Agency is entitled to substitute a dramatically higher number, such as

100,000. We are aware of no principle of administrative law that would

allow an agency to rewrite such a clear statutory term, and we shudder

to contemplate the effect that such a principle would have on demo-

cratic governance.

JUSTICE BREYER, however, claims to perceive no difference between

(a) reading the statute to exclude greenhouse gases from the term “any

air pollutant” in the permitting triggers, and (b) reading the statute to

exclude sources emitting less than 100,000 tons per year from the

statutory phrase “any . . . source with the potential to emit two hundred

and fifty tons per year or more.” See post, at 7. The two could scarcely

be further apart. As we have explained (and as EPA agrees), statutory

context makes plain that the Act’s operative provisions use “air pollu-

tant” to denote less than the full range of pollutants covered by the Act-

wide definition. See Part II–A–1, supra. It is therefore incumbent on

EPA to specify the pollutants encompassed by that term in the context

of a particular program, and to do so reasonably in light of that pro-

gram’s overall regulatory scheme. But there is no ambiguity whatso-

ever in the specific, numerical permitting thresholds, and thus no room

for EPA to exercise discretion in selecting a different threshold.

Cite as: 573 U. S. ____ (2014) 25

Opinion of the Court

become subject to PSD or Title V permitting by reason of

its greenhouse-gas emissions. But what about “anyway”

sources, those that would need permits based on their

emissions of more conventional pollutants (such as partic-

ulate matter)? We now consider whether EPA reasonably

interpreted the Act to require those sources to comply with

“best available control technology” emission standards for

greenhouse gases.

1

To obtain a PSD permit, a source must be “subject to the

best available control technology” for “each pollutant

subject to regulation under [the Act]” that it emits.

§7475(a)(4). The Act defines BACT as “an emission limita-

tion based on the maximum degree of reduction of each

pollutant subject to regulation” that is “achievable . . .

through application of production processes and available

methods, systems, and techniques, including fuel cleaning,

clean fuels, or treatment or innovative fuel combustion

techniques.” §7479(3). BACT is determined “on a case-by-

case basis, taking into account energy, environmental, and

economic impacts and other costs.” Ibid.

Some petitioners urge us to hold that EPA may never

require BACT for greenhouse gases—even when a source

must undergo PSD review based on its emissions of con-

ventional pollutants—because BACT is fundamentally

unsuited to greenhouse-gas regulation. BACT, they say,

has traditionally been about end-of-stack controls “such as

catalytic converters or particle collectors”; but applying it

to greenhouse gases will make it more about regulating

energy use, which will enable regulators to control “every

aspect of a facility’s operation and design,” right down to

the “light bulbs in the factory cafeteria.” Brief for Peti-

tioner Energy-Intensive Manufacturers Working Group on

Greenhouse Gas Regulation et al. in No. 12–1254, p. 7; see

Joint Reply Brief for Petitioners in No. 12–1248 etc., pp.

26 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

14–15 (“BACT for [greenhouse gases] becomes an un-

bounded exercise in command-and-control regulation” of

everything from “efficient light bulbs” to “basic industrial

processes”). But see Brief for Calpine Corp. as Amicus

Curiae 10 (“[I]n Calpine’s experience with ‘anyway’

sources, the [greenhouse-gas] analysis was only a small

part of the overall permitting process”).

EPA has published a guidance document that lends

some credence to petitioners’ fears. It states that at least

initially, compulsory improvements in energy efficiency

will be the “foundation” of greenhouse-gas BACT, with

more traditional end-of-stack controls either not used or

“added as they become more available.” PSD and Title V

Permitting Guidance for Greenhouse Gases 29 (Mar. 2011)

(hereinafter Guidance); see Peloso & Dobbins, Greenhouse

Gas PSD Permitting: The Year in Review, 42 Tex. Env.

L. J. 233, 247 (2012) (“Because [other controls] tend to

prove infeasible, energy efficiency measures dominate the

[greenhouse-gas] BACT controls approved by the states

and EPA”). But EPA’s guidance also states that BACT

analysis should consider options other than energy effi-

ciency, such as “carbon capture and storage.” Guidance

29, 32, 35–36, 42–43. EPA argues that carbon capture is

reasonably comparable to more traditional, end-of-stack

BACT technologies, id., at 32, n. 86, and petitioners do not

dispute that.

Moreover, assuming without deciding that BACT may

be used to force some improvements in energy efficiency,

there are important limitations on BACT that may work

to mitigate petitioners’ concerns about “unbounded” regu-

latory authority. For one, BACT is based on “control

technology” for the applicant’s “proposed facility,”

§7475(a)(4); therefore, it has long been held that BACT

cannot be used to order a fundamental redesign of the

facility. See, e.g., Sierra Club v. EPA, 499 F. 3d 653, 654–

655 (CA7 2007); In re Pennsauken Cty., N. J., Resource

Cite as: 573 U. S. ____ (2014) 27

Opinion of the Court

Recovery Facility, 2 E. A. D. 667, 673 (EAB 1988). For

another, EPA has long interpreted BACT as required only

for pollutants that the source itself emits, see 44 Fed. Reg.

51947 (1979); accordingly, EPA acknowledges that BACT

may not be used to require “reductions in a facility’s de-

mand for energy from the electric grid.” Guidance 24.

Finally, EPA’s guidance suggests that BACT should not

require every conceivable change that could result in

minor improvements in energy efficiency, such as the

aforementioned light bulbs. Id., at 31. The guidance

explains that permitting authorities should instead con-

sider whether a proposed regulatory burden outweighs

any reduction in emissions to be achieved, and should

concentrate on the facility’s equipment that uses the

largest amounts of energy. Ibid.

2

The question before us is whether EPA’s decision to

require BACT for greenhouse gases emitted by sources

otherwise subject to PSD review is, as a general matter, a

permissible interpretation of the statute under Chevron.

We conclude that it is.

The text of the BACT provision is far less open-ended

than the text of the PSD and Title V permitting triggers.

It states that BACT is required “for each pollutant subject

to regulation under this chapter” (i.e., the entire Act),

§7475(a)(4), a phrase that—as the D. C. Circuit wrote 35

years ago—“would not seem readily susceptible [of] misin-

terpretation.” Alabama Power Co. v. Costle, 636 F. 2d 323,

404 (1979). Whereas the dubious breadth of “any air

pollutant” in the permitting triggers suggests a role for

agency judgment in identifying the subset of pollutants

covered by the particular regulatory program at issue, the

more specific phrasing of the BACT provision suggests

that the necessary judgment has already been made by

Congress. The wider statutory context likewise does not

28 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of the Court

suggest that the BACT provision can bear a narrowing

construction: There is no indication that the Act elsewhere

uses, or that EPA has interpreted, “each pollutant subject

to regulation under this chapter” to mean anything other

than what it says.

Even if the text were not clear, applying BACT to

greenhouse gases is not so disastrously unworkable, and

need not result in such a dramatic expansion of agency

authority, as to convince us that EPA’s interpretation is

unreasonable. We are not talking about extending EPA

jurisdiction over millions of previously unregulated enti-

ties, but about moderately increasing the demands EPA

(or a state permitting authority) can make of entities

already subject to its regulation. And it is not yet clear

that EPA’s demands will be of a significantly different

character from those traditionally associated with PSD

review. In short, the record before us does not establish

that the BACT provision as written is incapable of being

sensibly applied to greenhouse gases.

We acknowledge the potential for greenhouse-gas BACT

to lead to an unreasonable and unanticipated degree of

regulation, and our decision should not be taken as an

endorsement of all aspects of EPA’s current approach, nor

as a free rein for any future regulatory application of

BACT in this distinct context. Our narrow holding is that

nothing in the statute categorically prohibits EPA from

interpreting the BACT provision to apply to greenhouse

gases emitted by “anyway” sources.

However, EPA may require an “anyway” source to com-

ply with greenhouse-gas BACT only if the source emits

more than a de minimis amount of greenhouse gases. As

noted above, the Tailoring Rule applies BACT only if a

source emits greenhouse gases in excess of 75,000 tons per

year CO2e, but the Rule makes clear that EPA did not

arrive at that number by identifying the de minimis level.

See nn. 1, 3, supra. EPA may establish an appropriate de

Cite as: 573 U. S. ____ (2014) 29

Opinion of SCALIA, J.

minimis threshold below which BACT is not required for a

source’s greenhouse-gas emissions. We do not hold that

75,000 tons per year CO2e necessarily exceeds a true de

minimis level, only that EPA must justify its selection on

proper grounds. Cf. Alabama Power, supra, at 405.9

* * *

To sum up: We hold that EPA exceeded its statutory

authority when it interpreted the Clean Air Act to require

PSD and Title V permitting for stationary sources based

on their greenhouse-gas emissions. Specifically, the Agency

may not treat greenhouse gases as a pollutant for pur-

poses of defining a “major emitting facility” (or a “modifi-

cation” thereof) in the PSD context or a “major source” in

the Title V context. To the extent its regulations purport

to do so, they are invalid. EPA may, however, continue to

treat greenhouse gases as a “pollutant subject to regula-

tion under this chapter” for purposes of requiring BACT

for “anyway” sources. The judgment of the Court of Ap-

peals is affirmed in part and reversed in part.

It is so ordered.

——————

9 JUSTICE ALITO argues that BACT is “fundamentally incompatible”

with greenhouse gases for two reasons. Post, at 4 (opinion concurring

in part and dissenting in part). First, BACT requires consideration of

“ambient air quality at the proposed site and in areas which may be

affected by emissions from [the proposed] facility for each pollutant

subject to regulation under this chapter,” §7475(e)(1); see also

§7475(e)(3)(B); and it is not obvious how that requirement should apply,

or even whether it can apply, to greenhouse gases. Post, at 4–5. But

the possibility that that requirement may be inoperative as to green-

house gases does not convince us that they must be categorically

excluded from BACT even though they are indisputably a “pollutant

subject to regulation.” Second, JUSTICE ALITO argues that EPA’s

guidance on how to implement greenhouse-gas BACT is a recipe for

“arbitrary and inconsistent decisionmaking.” Post, at 8. But we are not

reviewing EPA’s guidance in these cases, and we cannot say that it is

impossible for EPA and state permitting authorities to devise rational

ways of complying with the statute’s directive to determine BACT for

greenhouse gases “on a case-by-case basis, taking into account energy,

environmental, and economic impacts and other costs.” §7479(3).

Cite as: 573 U. S. ____ (2014) 1

Opinion of BREYER, J.

SUPREME COURT OF THE UNITED STATES

_________________

Nos. 12–1146, 12–1248, 12–1254, 12–1268, 12–1269, and 12–1272

_________________

UTILITY AIR REGULATORY GROUP,

PETITIONER

12–1146 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

AMERICAN CHEMISTRY COUNCIL, ET AL.,

PETITIONERS

12–1248 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

ENERGY-INTENSIVE MANUFACTURERS WORKING

GROUP ON GREENHOUSE GAS REGULATION,

ET AL., PETITIONERS

12–1254 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

SOUTHEASTERN LEGAL FOUNDATION, INC.,

ET AL., PETITIONERS

12–1268 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

TEXAS, ET AL., PETITIONERS

12–1269 v.

ENVIRONMENTAL PROTECTION AGENCY,

ET AL.; AND

CHAMBER OF COMMERCE OF THE UNITED

STATES, ET AL., PETITIONERS

12–1272 v.

2 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of BREYER, J.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

ON WRITS OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE DISTRICT OF COLUMBIA CIRCUIT

[June 23, 2014]

JUSTICE BREYER, with whom JUSTICE GINSBURG,

JUSTICE SOTOMAYOR, and JUSTICE KAGAN join, concurring

in part and dissenting in part.

In Massachusetts v. EPA, 549 U. S. 497 (2007), we held

that greenhouse gases fall within the Clean Air Act’s

general definition of the term “air pollutant,” 42 U. S. C.

§7602(g). 549 U. S., at 528–529. We also held, conse-

quently, that the Environmental Protection Agency is

empowered and required by Title II of the Act to regulate

greenhouse gas emissions from mobile sources (such as

cars and trucks) if it decides that greenhouse gases “con-

tribute to . . . air pollution which may reasonably be antic-

ipated to endanger public health or welfare,” §7521(a)(1).

549 U. S., at 532–533. The EPA determined that green-

house gases endanger human health and welfare, 74 Fed.

Reg. 66496 (2009) (Endangerment Finding), and so it

issued regulations for mobile emissions, 75 Fed. Reg.

25324 (2010) (Tailpipe Rule).

These cases take as a given our decision in Massachu-

setts that the Act’s general definition of “air pollutant”

includes greenhouse gases. One of the questions posed by

these cases is whether those gases fall within the scope of

the phrase “any air pollutant” as that phrase is used in the

more specific provisions of the Act here at issue. The

Court’s answer is “no.” Ante, at 10–24. I disagree.

The Clean Air Act provisions at issue here are Title I’s

Prevention of Significant Deterioration (PSD) program,

§7470 et seq., and Title V’s permitting regime, §7661 et

seq. By contrast to Title II, Titles I and V apply to sta-

tionary sources, such as power plants and factories. Un-

Cite as: 573 U. S. ____ (2014) 3

Opinion of BREYER, J.

der the PSD program, “major emitting facilities” con-

structed in the United States must meet certain require-

ments, including obtaining a permit that imposes emis-

sions limitations, §7475(a)(1), and using “the best

available control technology for each pollutant subject to

regulation under [the Act] emitted from” the facility,

§7475(a)(4). Title V requires each “major source” to obtain

an operating permit. §7661a(a).

These cases concern the definitions of “major emitting

facility” and “major source,” each of which is defined to

mean any stationary source that emits more than a

threshold quantity of “any air pollutant.” See §7479(1)

(“major emitting facility”); §§7602(j), 7661(2)(B) (“major

source”). To simplify the exposition, I will refer only to the

PSD program and its definition of “major emitting facility”;

a parallel analysis applies to Title V.

As it is used in the PSD provisions,

“[t]he term ‘major emitting facility’ means any of [a

list of specific categories of] stationary sources of air

pollutants which emit, or have the potential to emit,

one hundred tons per year or more of any air pollutant

. . . . Such term also includes any other source with

the potential to emit two hundred and fifty tons per

year or more of any air pollutant.” §7479(1).

To simplify further, I will ignore the reference to specific

types of source that emit at least 100 tons per year (tpy) of

any air pollutant. In effect, we are dealing with a statute

that says that the PSD program’s regulatory requirements

must be applied to

“any stationary source that has the potential to emit

two hundred fifty tons per year or more of any air

pollutant.”

The interpretive difficulty in these cases arises out of

the definition’s use of the phrase “two hundred fifty tons

4 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of BREYER, J.

per year or more,” which I will call the “250 tpy threshold.”

When applied to greenhouse gases, 250 tpy is far too low a

threshold. As the Court explains, tens of thousands of

stationary sources emit large quantities of one greenhouse

gas, carbon dioxide. See ante, at 17–20, and n. 7. To

apply the programs at issue here to all those sources

would be extremely expensive and burdensome, counter-

productive, and perhaps impossible; it would also contra-

vene Congress’s intent that the programs’ coverage be

limited to those large sources whose emissions are sub-

stantial enough to justify the regulatory burdens. Ibid.

The EPA recognized as much, and it addressed the prob-

lem by issuing a regulation—the Tailoring Rule—that

purports to raise the coverage threshold for greenhouse

gases from the statutory figure of 250 tpy to 100,000 tpy

in order to keep the programs’ coverage limited to “a rela-

tively small number of large industrial sources.” 75 Fed.

Reg. 31514, 31555 (2010); see id., at 31523–31524.

The Tailoring Rule solves the practical problems that

would have been caused by the 250 tpy threshold. But

what are we to do about the statute’s language? The

statute specifies a definite number—250, not 100,000—

and it says that facilities that are covered by that number

must meet the program’s requirements. The statute says

nothing about agency discretion to change that number.

What is to be done? How, given the statute’s language,

can the EPA exempt from regulation sources that emit

more than 250 but less than 100,000 tpy of greenhouse

gases (and that also do not emit other regulated pollutants

at threshold levels)?

The Court answers by (1) pointing out that regulation at

the 250 tpy threshold would produce absurd results, (2)

refusing to read the statute as compelling such results,

and (3) consequently interpreting the phrase “any air

pollutant” as containing an implicit exception for green-

house gases. (Emphasis added.) Put differently, the

Cite as: 573 U. S. ____ (2014) 5

Opinion of BREYER, J.

Court reads the statute as defining “major emitting facility”

to mean “stationary sources that have the potential to

emit two hundred fifty tons per year or more of any air

pollutant except for those air pollutants, such as carbon

dioxide, with respect to which regulation at that threshold

would be impractical or absurd or would sweep in smaller

sources that Congress did not mean to cover.” See ante, at

15–16 (“[T]here is no insuperable textual barrier to EPA’s

interpreting ‘any air pollutant’ in the permitting triggers

of PSD and Title V to encompass only pollutants emitted

in quantities that enable them to be sensibly regulated at

the statutory thresholds, and to exclude those atypical

pollutants that, like greenhouse gases, are emitted in such

vast quantities that their inclusion would radically trans-

form those programs and render them unworkable as

written”).

I agree with the Court that the word “any,” when used

in a statute, does not normally mean “any in the uni-

verse.” Cf. FCC v. NextWave Personal Communications

Inc., 537 U. S. 293, 311 (2003) (BREYER, J., dissenting)

(“ ‘Tell all customers that . . .’ does not refer to every cus-

tomer of every business in the world”). Rather, “[g]eneral

terms as used on particular occasions often carry with

them implied restrictions as to scope,” ibid., and so courts

must interpret the word “any,” like all other words, in

context. As Judge Learned Hand pointed out when inter-

preting another statute many years ago, “[w]e can best

reach the meaning here, as always, by recourse to the

underlying purpose, and, with that as a guide, by trying to

project upon the specific occasion how we think persons,

actuated by such a purpose, would have dealt with it, if it

had been presented to them at the time.” Borella v. Bor-

den Co., 145 F. 2d 63, 64 (CA2 1944). The pursuit of that

underlying purpose may sometimes require us to “aban-

don” a “literal interpretation” of a word like “any.” Id., at

64–65.

6 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of BREYER, J.

The law has long recognized that terms such as “any”

admit of unwritten limitations and exceptions. Legal

philosophers like to point out that a statute providing that

“ ‘[w]hoever shall willfully take the life of another shall be

punished by death’ ” need not encompass a man who kills

in self-defense; nor must an ordinance imposing fines upon

those who occupy a public parking spot for more than two

hours penalize a driver who is unable to move because of a

parade. See Fuller, The Case of the Speluncean Explorers,

62 Harv. L. Rev. 616, 619, 624 (1949); see also United

States v. Kirby, 7 Wall. 482, 485–487 (1869) (holding that

a statute forbidding knowing and willful obstruction of the

mail contains an implicit exception permitting a local

sheriff to arrest a mail carrier). The maxim cessante

ratione legis cessat ipse lex—where a law’s rationale ceases

to apply, so does the law itself—is not of recent origin.

See, e.g., Zadvydas v. Davis, 533 U. S. 678, 699 (2001)

(citing 1 E. Coke, Institutes *70b); Green v. Liter, 8 Cranch

229, 249 (1814) (Story, J.) (“cessante ratione, cessat ipsa

lex”).

I also agree with the Court’s point that “a generic refer-

ence to air pollutants” in the Clean Air Act need not “en-

compass every substance falling within the Act-wide

definition” that we construed in Massachusetts, §7602(g).

See ante, at 12–13. As the Court notes, the EPA has

interpreted the phrase “any air pollutant,” which is used

several times in the Act, as limited to “air pollutants for

which EPA has promulgated [new source performance

standards]” in the portion of the Act dealing with those

standards, as limited to “visibility-impairing air pollu-

tants” in the part of the Act concerned with deleterious

effects on visibility, and as limited to “pollutants for which

the area is designated nonattainment” in the part of the

Act aimed at regions that fail to attain air quality stand-

ards. Ibid.

But I do not agree with the Court that the only way to

Cite as: 573 U. S. ____ (2014) 7

Opinion of BREYER, J.

avoid an absurd or otherwise impermissible result in these

cases is to create an atextual greenhouse gas exception to

the phrase “any air pollutant.” After all, the word “any”

makes an earlier appearance in the definitional provision,

which defines “major emitting facility” to mean “any . . .

source with the potential to emit two hundred and fifty

tons per year or more of any air pollutant.” §7479(1)

(emphasis added). As a linguistic matter, one can just as

easily read an implicit exception for small-scale green-

house gas emissions into the phrase “any source” as into

the phrase “any air pollutant.” And given the purposes of

the PSD program and the Act as a whole, as well as the

specific roles of the different parts of the statutory defini-

tion, finding flexibility in “any source” is far more sensible

than the Court’s route of finding it in “any air pollutant.”

The implicit exception I propose reads almost word for

word the same as the Court’s, except that the location of

the exception has shifted. To repeat, the Court reads the

definition of “major emitting facility” as if it referred to

“any source with the potential to emit two hundred fifty

tons per year or more of any air pollutant except for those

air pollutants, such as carbon dioxide, with respect to

which regulation at that threshold would be impractical or

absurd or would sweep in smaller sources that Congress

did not mean to cover.” I would simply move the implicit

exception, which I’ve italicized, so that it applies to

“source” rather than “air pollutant”: “any source with the

potential to emit two hundred fifty tons per year or more

of any air pollutant except for those sources, such as those

emitting unmanageably small amounts of greenhouse

gases, with respect to which regulation at that threshold

would be impractical or absurd or would sweep in smaller

sources that Congress did not mean to cover.”

From a legal, administrative, and functional perspec-

tive—that is, from a perspective that assumes that Con-

gress was not merely trying to arrange words on paper but

8 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of BREYER, J.

was seeking to achieve a real-world purpose—my way of

reading the statute is the more sensible one. For one

thing, my reading is consistent with the specific purpose

underlying the 250 tpy threshold specified by the statute.

The purpose of that number was not to prevent the regula-

tion of dangerous air pollutants that cannot be sensibly

regulated at that particular threshold, though that is the

effect that the Court’s reading gives the threshold. Ra-

ther, the purpose was to limit the PSD program’s obliga-

tions to larger sources while exempting the many small

sources whose emissions are low enough that imposing

burdensome regulatory requirements on them would be

senseless.

Thus, the accompanying Senate Report explains that

the PSD program “is reasonable and necessary for very

large sources, such as new electrical generating plants or

new steel mills. But the procedure would prove costly and

potentially unreasonable if imposed on construction of

storage facilities for a small gasoline jobber or on the

construction of a new heating plant at a junior college.”

S. Rep. No. 95–127, p. 96 (1977). And the principal spon-

sor of the Clean Air Act amendments at issue here, Sena-

tor Edmund Muskie, told the Senate that the program

would not cover “houses, dairies, farms, highways, hospi-

tals, schools, grocery stores, and other such sources.” 123

Cong. Rec. 18013, 18021 (1977).

The EPA, exercising the legal authority to which it is

entitled under Chevron U. S. A. Inc. v. Natural Resources

Defense Council, Inc., 467 U. S. 837 (1984), understood the

threshold’s purpose in the same light. It explained that

Congress’s objective was

“to limit the PSD program to large industrial sources

because it was those sources that were the primary

cause of the pollution problems in question and be-

cause those sources would have the resources to com-

Cite as: 573 U. S. ____ (2014) 9

Opinion of BREYER, J.

ply with the PSD requirements. Congress’s mecha-

nism for limiting PSD was the 100/250 tpy threshold

limitations. Focused as it was primarily on NAAQS

pollutants [that is, those air pollutants for which the

EPA has issued a national ambient air quality stand-

ard under Title I of the Act, see EPA v. EME Homer

City Generation, L. P., 572 U. S. ___, ___ (2014) (slip

op., at 4)], Congress considered sources that emit

NAAQS pollutants in those quantities generally to be

the large industrial sources to which it intended PSD

to be limited.” Tailoring Rule, 75 Fed. Reg. 31555.

The Court similarly acknowledges that “the PSD pro-

gram and Title V are designed to apply to, and cannot

rationally be extended beyond, a relative handful of large

sources capable of shouldering heavy substantive and

procedural burdens.” Ante, at 18; see also Alabama Power

Co. v. Costle, 636 F. 2d 323, 353 (CADC 1979) (“Congress’s

intention was to identify facilities which, due to their size,

are financially able to bear the substantial regulatory

costs imposed by the PSD provisions and which, as a

group, are primarily responsible for emission of the delete-

rious pollutants that befoul our nation’s air”).

An implicit source-related exception would serve this

statutory purpose while going no further. The implicit

exception that the Court reads into the phrase “any air

pollutant,” by contrast, goes well beyond the limited con-

gressional objective. Nothing in the statutory text, the

legislative history, or common sense suggests that Con-

gress, when it imposed the 250 tpy threshold, was trying

to undermine its own deliberate decision to use the broad

language “any air pollutant” by removing some substances

(rather than some facilities) from the PSD program’s

coverage.

For another thing, a source-related exception serves the

flexible nature of the Clean Air Act. We observed in Mas-

10 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of BREYER, J.

sachusetts that “[w]hile the Congresses that drafted” the

Act “might not have appreciated the possibility that burn-

ing fossil fuels could lead to global warming, they did

understand that without regulatory flexibility, changing

circumstances and scientific developments would soon

render the Clean Air Act obsolete.” 549 U. S., at 532. We

recognized that “[t]he broad language of ” the Act-wide

definition of “air pollutant” “reflects an intentional effort

to confer the flexibility necessary to forestall such obsoles-

cence.” Ibid.

The Court’s decision to read greenhouse gases out of the

PSD program drains the Act of its flexibility and chips

away at our decision in Massachusetts. What sense does it

make to read the Act as generally granting the EPA the

authority to regulate greenhouse gas emissions and then

to read it as denying that power with respect to the pro-

grams for large stationary sources at issue here? It is

anomalous to read the Act to require the EPA to regulate

air pollutants that pose previously unforeseen threats to

human health and welfare where “250 tons per year” is a

sensible regulatory line but not where, by chemical or

regulatory happenstance, a higher line must be drawn.

And it is anomalous to read an unwritten exception into

the more important phrase of the statutory definition

(“any air pollutant”) when a similar unwritten exception to

less important language (the particular number used by

the statute) will do just as well. The implicit exception

preferred by the Court produces all of these anomalies,

while the source-related exception I propose creates none

of them.

In addition, the interpretation I propose leaves the EPA

with the sort of discretion as to interstitial matters that

Congress likely intended it to retain. My interpretation

gives the EPA nothing more than the authority to exempt

sources from regulation insofar as the Agency reasonably

determines that applying the PSD program to them would

Cite as: 573 U. S. ____ (2014) 11

Opinion of BREYER, J.

expand the program so much as to contravene Congress’s

intent. That sort of decision, which involves the Agency’s

technical expertise and administrative experience, is the

kind of decision that Congress typically leaves to the

agencies to make. Cf. Barnhart v. Walton, 535 U. S. 212,

222 (2002) (enumerating factors that we take to indicate

that Congress intends the agency to exercise the discre-

tion provided by Chevron). To read the Act to grant that

discretion here is to read it as furthering Congress’s (and

the public’s) interest in more effective, less wasteful

regulation.

Last, but by no means least, a source-related exception

advances the Act’s overall purpose. That broad purpose,

as set forth at the beginning of the statute, is “to protect

and enhance the quality of the Nation’s air resources so as

to promote the public health and welfare and the produc-

tive capacity of its population.” §7401(b)(1); see also

§7470(1) (A purpose of the PSD program in particular

is “to protect public health and welfare from any actual

or potential adverse effect which in the Administra-

tor’s judgment may reasonably be anticipate[d] to occur

from air pollution”); §7602(h) (“All language [in the Act]

referring to effects on welfare includes . . . effects on . . .

weather . . . and climate”). The expert agency charged

with administering the Act has determined in its En-

dangerment Finding that greenhouse gases endanger

human health and welfare, and so sensible regulation of

industrial emissions of those pollutants is at the core of

the purpose behind the Act. The broad “no greenhouse

gases” exception that the Court reads into the statute

unnecessarily undercuts that purpose, while my narrow

source-related exception would leave the Agency with the

tools it needs to further it.

* * *

I agree with the Court’s holding that stationary sources

12 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of BREYER, J.

that are subject to the PSD program because they emit

other (non-greenhouse-gas) pollutants in quantities above

the statutory threshold—those facilities that the Court

refers to as “anyway” sources—must meet the “best avail-

able control technology” requirement of §7475(a)(4) with

respect to greenhouse gas emissions. I therefore join Part

II–B–2 of the Court’s opinion. But as for the Court’s hold-

ing that the EPA cannot interpret the language at issue

here to cover facilities that emit more than 100,000 tpy of

greenhouse gases by virtue of those emissions, I respect-

fully dissent.

Cite as: 573 U. S. ____ (2014) 1

Opinion of ALITO, J.

SUPREME COURT OF THE UNITED STATES

_________________

Nos. 12–1146, 12–1248, 12–1254, 12–1268, 12–1269, and 12–1272

_________________

UTILITY AIR REGULATORY GROUP,

PETITIONER

12–1146 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

AMERICAN CHEMISTRY COUNCIL, ET AL.,

PETITIONERS

12–1248 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

ENERGY-INTENSIVE MANUFACTURERS WORKING

GROUP ON GREENHOUSE GAS REGULATION,

ET AL., PETITIONERS

12–1254 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

SOUTHEASTERN LEGAL FOUNDATION, INC.,

ET AL., PETITIONERS

12–1268 v.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

TEXAS, ET AL., PETITIONERS

12–1269 v.

ENVIRONMENTAL PROTECTION AGENCY,

ET AL.; AND

CHAMBER OF COMMERCE OF THE UNITED

STATES, ET AL., PETITIONERS

12–1272 v.

2 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of ALITO, J.

ENVIRONMENTAL PROTECTION AGENCY, ET AL.;

ON WRITS OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE DISTRICT OF COLUMBIA CIRCUIT

[June 23, 2014]

JUSTICE ALITO, with whom JUSTICE THOMAS joins,

concurring in part and dissenting in part.

In Massachusetts v. EPA, 549 U. S. 497 (2007), this

Court considered whether greenhouse gases fall within the

Clean Air Act’s general definition of an air “pollutant.”

Id., at 528–529. The Environmental Protection Agency

cautioned us that “key provisions of the [Act] cannot co-

gently be applied to [greenhouse gas] emissions,” Brief for

Federal Respondent in Massachusetts v. EPA, O. T. 2006,

No. 05–1120, p. 22, but the Court brushed the warning

aside and had “little trouble” concluding that the Act’s

“sweeping definition” of a pollutant encompasses green-

house gases. 549 U. S., at 528–529. I believed Massachu-

setts v. EPA was wrongly decided at the time, and these

cases further expose the flaws with that decision.

I

As the present cases now show, trying to fit greenhouse

gases into “key provisions” of the Clean Air Act involves

more than a “little trouble.” These cases concern the

provisions of the Act relating to the “Prevention of Signifi-

cant Deterioration” (PSD), 42 U. S. C. §§7470–7492, as

well as Title V of the Act, §7661. And in order to make

those provisions apply to greenhouse gases in a way that

does not produce absurd results, the EPA effectively

amended the Act. The Act contains specific emissions

thresholds that trigger PSD and Title V coverage, but the

EPA crossed out the figures enacted by Congress and

substituted figures of its own.

I agree with the Court that the EPA is neither required

nor permitted to take this extraordinary step, and I there-

Cite as: 573 U. S. ____ (2014) 3

Opinion of ALITO, J.

fore join Parts I and II–A of the Court’s opinion.

II

I do not agree, however, with the Court’s conclusion that

what it terms “anyway sources,” i.e., sources that are

subject to PSD and Title V permitting as the result of the

emission of conventional pollutants, must install “best

available control technology” (BACT) for greenhouse gases.

As is the case with the PSD and Title V thresholds,

trying to fit greenhouse gases into the BACT analysis

badly distorts the scheme that Congress adopted.

The Court gives two main reasons for concluding that

BACT applies to “anyway” sources, one based on text

and one based on practical considerations. Neither is

convincing.

A

With respect to the text, it is curious that the Court,

having departed from a literal interpretation of the term

“pollutant” in Part II–A, turns on its heels and adopts a

literal interpretation in Part II–B. The coverage thresh-

olds at issue in Part II–A apply to any “pollutant.” The

Act’s general definition of this term is broad, and in Mas-

sachusetts v. EPA, supra, the Court held that this defini-

tion covers greenhouse gases. The Court does not disturb

that holding, but it nevertheless concludes that, as used in

the provision triggering PSD coverage, the term “pollu-

tant” actually means “pollutant, other than a greenhouse

gas.”

In Part II–B, the relevant statutory provision says

that BACT must be installed for any “pollutant subject

to regulation under [the Act].” §7475(a)(4). If the term

“pollutant” means “pollutant, other than a greenhouse

gas,” as the Court effectively concludes in Part II–A, the

term “pollutant subject to regulation under [the Act]” in

§7475(a)(4) should mean “pollutant, other than a green-

4 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of ALITO, J.

house gas, subject to regulation under [the Act], and that

is subject to regulation under [the Act].” The Court’s

literalism is selective, and it results in a strange and

disjointed regulatory scheme.

Under the Court’s interpretation, a source can emit an

unlimited quantity of greenhouse gases without triggering

the need for a PSD permit. Why might Congress have

wanted to allow this? The most likely explanation is that

the PSD permitting process is simply not suited for use in

regulating this particular pollutant. And if that is so, it

makes little sense to require the installation of BACT for

greenhouse gases in those instances in which a source

happens to be required to obtain a permit due to the emis-

sion of a qualifying quantity of some other pollutant that

is regulated under the Act.

B

The Court’s second reason for holding that BACT ap-

plies to “anyway” sources is its belief that this can be done

without disastrous consequences. Only time will tell

whether this hope is well founded, but it seems clear that

BACT analysis is fundamentally incompatible with the

regulation of greenhouse-gas emissions for at least two

important reasons.

1

First, BACT looks to the effects of covered pollutants in

the area in which a source is located. The PSD program is

implemented through “emission limitations and such

other measures” as are “necessary . . . to prevent signifi-

cant deterioration of air quality in each region.” §7471

(emphasis added). The Clean Air Act provides that BACT

must be identified “on a case-by-case basis,” §7479(3), and

this necessarily means that local conditions must be taken

into account. For this reason, the Act instructs the EPA to

issue regulations requiring an analysis of “the ambient air

Cite as: 573 U. S. ____ (2014) 5

Opinion of ALITO, J.

quality . . . at the site of the proposed major emitting facil-

ity and in the area potentially affected by the emissions

from such facility for each pollutant regulated under [the

Act].” §7475(e)(3)(B) (emphasis added). The Act also

requires a public hearing on “the air quality at the pro-

posed site and in areas which may be affected by emissions

from such facility for each pollutant subject to regulation

under [the Act] which will be emitted from such facility.”

§§7475(a)(2), (e)(1) (emphasis added). Accordingly, if

BACT is required for greenhouse gases, the Act demands

that the impact of these gases in the area surrounding a

site must be monitored, explored at a public hearing, and

considered as part of the permitting process. The effects of

greenhouse gases, however, are global, not local. See PSD

and Title V Permitting Guidance for Greenhouse Gases

41–42 (Mar. 2011) (hereinafter Guidance). As a result, the

EPA has declared that PSD permit applicants and permit-

ting officials may disregard these provisions of the Act. 75

Fed. Reg. 31520 (2010).

2

Second, as part of the case-by-case analysis required by

BACT, a permitting authority must balance the environ-

mental benefit expected to result from the installation of

an available control measure against adverse consequences

that may result, including any negative impact on the

environment, energy conservation, and the economy. And

the EPA itself has admitted that this cannot be done on a

case-by-case basis with respect to greenhouse gases.

The Clean Air Act makes it clear that BACT must be

determined on a “case-by-case basis, taking into account

energy, environmental, and economic impacts and other

costs.” §7479(3). To implement this directive, the EPA

adopted a five-step framework for making a BACT deter-

mination. See New Source Review Workshop Manual:

Prevention of Significant Deterioration and Nonattain-

6 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of ALITO, J.

ment Area Permitting (Oct. 1990).1 Under the fourth step

of this analysis, potentially applicable and feasible control

technologies that are candidates for selection as BACT for

a particular source are eliminated from consideration

based on their “collateral impacts,” such as any adverse

environmental effects or adverse effects on energy con-

sumption or the economy.

More recently, the EPA provided guidance to permitting

authorities regarding the treatment of greenhouse-gas

emissions under this framework, and the EPA’s guidance

demonstrates the insuperable problem that results when

an attempt is made to apply this framework to greenhouse

gas emissions. As noted above, at step 4 of the framework,

a permitting authority must balance the positive effect

likely to result from requiring a particular source to install

a particular technology against a variety of negative ef-

fects that are likely to occur if that step is taken. But

in the case of greenhouse gases, how can a permit-

ting authority make this individualized, source-specific

determination?

The EPA instructs permitting authorities to take into

——————

1 The

EPA describes these steps as follows:

(1) The applicant must identify all available control options that are

potentially applicable by consulting EPA’s BACT clearinghouse along

with other reliable sources.

(2) The technical feasibility of the control options identified in step 1

are eliminated based on technical infeasibility.

(3) The control technologies are ranked based on control effective-

ness, by considering: the percentage of the pollutant removed; expected

emission rate for each new source review (NSR) pollutant; expected

emission reduction for each regulated NSR pollutant; and output based

emissions limit.

(4) Control technologies are eliminated based on collateral impacts,

such as: energy impacts; other environmental impacts; solid or hazard-

ous waste; water discharge from control device; emissions of air toxics

and other non-NSR regulated pollutants; and economic impacts.

(5) The most effective control option not eliminated in step 4 is

proposed as BACT for the pollutant and emission unit under review.

Cite as: 573 U. S. ____ (2014) 7

Opinion of ALITO, J.

consideration all the adverse effects that the EPA has

found to result from the overall increase in greenhouse

gases in the atmosphere. These include an increased risk

of dangerous heat waves, hurricanes, floods, wildfires, and

drought, as well as risks to agriculture, forestry, and

water resources. Guidance 40–41. But the EPA admits

that it is simply not possible for a permitting authority to

calculate in any meaningful way the degree to which any

potential reduction in greenhouse gas emissions from any

individual source might reduce these risks. And without

making such a calculation in even a very rough way, a

permitting authority cannot do what the Clean Air Act

and the EPA’s framework demand—compare the benefits

of some specified reduction in the emission of greenhouse

gases from a particular source with any adverse environ-

mental or economic effects that might result from mandat-

ing such a reduction.

Suppose, for example, that a permitting authority must

decide whether to mandate a change that both decreases a

source’s emission of greenhouse gases and increases its

emission of a conventional pollutant that has a negative

effect on public health. How should a permitting authority

decide whether to require this change? Here is the EPA’s

advice:

“[W]hen considering the trade-offs between the envi-

ronmental impacts of a particular level of GHG

[greenhouse gas] reduction and a collateral increase in

another regulated NSR pollutant,[2] rather than at-

tempting to determine or characterize specific envi-

ronmental impacts from GHGs emitted at particular

locations, EPA recommends that permitting authori-

ties focus on the amount of GHG emission reductions

——————

2 “New source review pollutants” are those pollutants for which a

National Ambient Air Quality standard has been set and a few others,

such as sulphur dioxide. See 40 CFR 51.165(a)(1)(xxxvii) (2013).

8 UTILITY AIR REGULATORY GROUP v. EPA

Opinion of ALITO, J.

that may be gained or lost by employing a particular

control strategy and how that compares to the envi-

ronmental or other impacts resulting from the collat-

eral emissions increase of other regulated NSR pollu-

tants.” Guidance 42.

As best I can make out, what this means is that permit-

ting authorities should not even try to assess the net

impact on public health. Instead of comparing the positive

and negative public health effects of a particular option,

permitting authorities are instructed to compare the

adverse public health effects of increasing the emissions of

the conventional pollutants with the amount of the reduc-

tion of the source’s emissions of greenhouse gases. But

without knowing the positive effects of the latter, this is a

meaningless comparison.

The EPA tries to ameliorate this problem by noting that

permitting authorities are entitled to “a great deal of

discretion,” Guidance 41, but without a comprehensible

standard, what this will mean is arbitrary and incon-

sistent decisionmaking. That is not what the Clean Air

Act contemplates.3

* * *

BACT analysis, like the rest of the Clean Air Act, was

developed for use in regulating the emission of conven-

tional pollutants and is simply not suited for use with

respect to greenhouse gases. I therefore respectfully

dissent from Part II–B–2 of the opinion of the Court.

——————

3 WhileI do not think that BACT applies at all to “anyway sources,” if

it is to apply, the limitations suggested in Part II–B–1 might lessen the

inconsistencies highlighted in Part II of this opinion, and on that

understanding I join Part II–B–1.