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SUPREME COURT OF THE UNITED STATES
_________________
Nos. 12–1182 and 12–1183
_________________
ENVIRONMENTAL PROTECTION AGENCY
et al.,PETITIONERS
12–1182 v.
EME HOMER CITY GENERATION, L. P.,
et al.; and
AMERICAN LUNG ASSOCIATION
et al.,PETITIONERS
12–1183 v.
EME HOMER CITY GENERATION, L. P.,
et al.
on writs of certiorari to the united states
court of appeals for the district of columbia circuit
[April 29, 2014]
Justice Ginsburg
delivered the opinion of the Court.
These cases concern the
efforts of Congress and the Environmental Protection Agency (EPA or
Agency) to cope with a complex problem: air pollution emitted in
one State, but causing harm in other States. Left unregulated, the
emitting or upwind State reaps the benefits of the economic
activity causing the pollution without bearing all the costs. See
Revesz, Federalism and Interstate Environmental Externalities, 144
U. Pa. L. Rev. 2341, 2343 (1996). Conversely, downwind
States to which the pollution travels are unable to achieve clean
air because of the influx of out-of-state pollution they lack
authority to control. See S. Rep. No. 101–228, p. 49
(1989). To tackle the problem, Congress included a Good Neighbor
Provision in the Clean Air Act (Act or CAA). That provision, in its
current phrasing, instructs States to prohibit in-state sources
“from emitting any air pollutant in amounts which will
. . . contribute significantly” to downwind
States’ “nonattainment . . . , or interfere
with maintenance,” of any EPA-promulgated national air
quality standard. 42 U. S. C. §7410(a)(2)(D)(i).
Interpreting the Good
Neighbor Provision, EPA adopted the Cross-State Air Pollution Rule
(commonly and hereinafter called the Transport Rule). The rule
calls for consideration of costs, among other factors, when
determining the emission reductions an upwind State must make to
improve air quality in polluted downwind areas. The Court of
Appeals for the D. C. Circuit vacated the rule in its
entirety. It held, 2 to 1, that the Good Neighbor Provision
requires EPA to consider only each upwind State’s physically
proportionate responsibility for each downwind State’s air
quality problem. That reading is demanded, according to the
D. C. Circuit, so that no State will be required to decrease
its emissions by more than its ratable share of downwind-state
pollution.
In Chevron
U. S. A. Inc. v. Natural Resources Defense Council, Inc.,
467 U. S. 837 (1984) , we reversed a D. C. Circuit
decision that failed to accord deference to EPA’s reasonable
interpretation of an ambiguous Clean Air Act provision. Satisfied
that the Good Neighbor Provision does not command the Court of
Appeals’ cost-blind construction, and that EPA reasonably
interpreted the provision, we reverse the D. C.
Circuit’s judgment.
I
A
Air pollution is
transient, heedless of state boundaries. Pollutants generated by
upwind sources are often transported by air currents, sometimes
over hundreds of miles, to downwind States. As the pollution
travels out of state, upwind States are relieved of the associated
costs. Those costs are borne instead by the downwind States, whose
ability to achieve and maintain satisfactory air quality is
hampered by the steady stream of infiltrating pollution.
For several reasons,
curtailing interstate air pollution poses a complex challenge for
environmental regulators. First, identifying the upwind origin of
downwind air pollution is no easy endeavor. Most upwind States
propel pollutants to more than one downwind State, many downwind
States receive pollution from multiple upwind States, and some
States qualify as both upwind and downwind. See Brief for Federal
Petitioners 6. The overlapping and interwoven linkages between
upwind and downwind States with which EPA had to contend number in
the thousands.[
1]
Further complicating
the problem, pollutants do not emerge from the smokestacks of an
upwind State and uniformly migrate downwind. Some pollutants stay
within upwind States’ borders, the wind carries others to
downwind States, and some subset of that group drifts to States
without air quality problems. “The wind bloweth where it
listeth, and thou hearest the sound thereof, but canst not tell
whence it cometh, and whither it goeth.” The Holy Bible, John
3:8 (King James Version). In crafting a solution to the problem of
interstate air pollution, regulators must account for the vagaries
of the wind.
Finally, upwind
pollutants that find their way downwind are not left unaltered by
the journey. Rather, as the gases emitted by upwind polluters are
carried downwind, they are transformed, through various chemical
processes, into altogether different pollutants. The offending
gases at issue in these cases—nitrogen oxide (NOX) and sulfur
dioxide (SO2)—often develop into ozone and fine particulate
matter (PM2.5) by the time they reach the atmospheres of downwind
States. See 76 Fed. Reg. 48222–48223 (2011). See also 69 Fed.
Reg. 4575–4576 (2004) (describing the components of ozone and
PM2.5). Downwind air quality must therefore be measured for ozone
and PM2.5 concentrations. EPA’s chore is to quantify the
amount of upwind gases (NOX and SO2) that must be reduced to enable
downwind States to keep their levels of ozone and PM2.5 in
check.
B
Over the past 50
years, Congress has addressed interstate air pollution several
times and with increasing rigor. In 1963, Congress directed federal
authorities to “encourage cooperative activities by the
States and local governments for the prevention and control of air
pollution.” 77Stat. 393, 42 U. S. C. §1857a
(1964 ed.). In 1970, Congress made this instruction more concrete,
introducing features still key to the Act. For the first time,
Congress directed EPA to establish national ambient air quality
standards (NAAQS) for pollutants at levels that will protect public
health. See 84Stat. 1679–1680, as amended, 42
U. S. C. §§7408, 7409 (2006 ed.). Once EPA
settles on a NAAQS, the Act requires the Agency to designate
“nonattainment” areas, i.e., locations where the
concentration of a regulated pollutant exceeds the NAAQS.
§7407(d).
The Act then shifts the
burden to States to propose plans adequate for compliance with the
NAAQS. Each State must submit a State Implementation Plan, or SIP,
to EPA within three years of any new or revised NAAQS.
§7410(a)(1). If EPA determines that a State has failed to
submit an adequate SIP, either in whole or in part, the Act
requires the Agency to promulgate a Federal Implementation Plan, or
FIP, within two years of EPA’s determina-tion, “unless
the State corrects the deficiency” before a FIP is issued.
§7410(c)(1).[
2]
The Act lists the
matters a SIP must cover. Among SIP components, the 1970 version of
the Act required SIPs to include “adequate provisions for
intergovernmental cooperation” concerning interstate air
pollution. §110(a)(2)(E), 84Stat. 1681, 42 U. S. C.
§1857c–5(a)(2)(E). This statutory requirement, with its
text altered over time, has cometo be called the Good Neighbor
Provision.
In 1977, Congress
amended the Good Neighbor Provision to require more than
“cooperation.” It directed States to submit SIPs that
included provisions “adequate” to “prohibi[t] any
stationary source within the State from emitting any air pollutant
in amounts which will . . . prevent attainment or
maintenance [of air quality standards] by any other State.”
§108(a)(4), 91Stat. 693, 42 U. S. C.
§7410(a)(2)(E) (1976 ed., Supp. II). The amended provision
thus explicitly instructed upwind States to reduce emissions to
account for pollution exported beyond their borders. As then
written, however, the provision regulated only individual sources
that, considered alone, emitted enough pollution to cause
nonattainment in a downwind State. Because it is often
“impossible to say that any single source or group of sources
is the one which actually prevents attainment” downwind,
S. Rep. No. 101–228, p. 21 (1989), the 1977 version
of the Good Neighbor Provision proved ineffective, see ibid.
(noting the provision’s inability to curb the collective
“emissions [of] multiple sources”).
Congress most recently
amended the Good Neighbor Provision in 1990. The statute, in its
current form, requires SIPs to “contain adequate provisions
. . . prohibiting . . . any source or other
type of emissions activity within the State from emitting any air
pollutant in amounts which will . . . contribute
significantly to nonattainment in, or interfere with maintenance
by, any other State with respect to any . . .
[NAAQS].” 42 U. S. C. §7410(a)(2)(D)(i) (2006
ed.). The controversy before us centers on EPA’s most recent
attempt to construe this provision.
C
Three times over the
past two decades, EPA has attempted to delineate the Good Neighbor
Provision’s scope by identifying when upwind States
“contribute significantly” to nonattainment downwind.
In 1998, EPA issued arule known as the “NOX SIP Call.”
That regulation limited NOX emissions in 23 upwind States to the
extent such emissions contributed to nonattainment of ozone
standards in downwind States. See 63 Fed. Reg. 57356, 57358. In
Michigan v. EPA, 213 F. 3d 663 (2000), the D. C. Circuit
upheld the NOX SIP Call, specifically affirming EPA’s use of
costs to determine when an upwind State’s contribution was
“significan[t]” within the meaning of the statute. Id.,
at 674–679.
In 2005, EPA issued the
Clean Air Interstate Rule, or CAIR. 70 Fed. Reg. 25162. CAIR
regulated both NOX and SO2 emissions, insofar as such emissions
contributed to downwind nonattainment of two NAAQS, both set in
1997, one concerning the permissible annual measure of PM2.5, and
another capping the average ozone level gauged over an 8-hour
period. See id., at 25171. The D. C. Circuit initially vacated
CAIR as arbitrary and capricious. See North Carolina v. EPA, 531
F. 3d 896, 921 (2008) (per curiam). On rehearing, the court
decided to leave the rule in place, while encouraging EPA to act
with dispatch in dealing with problems the court had identified.
See North Carolina v. EPA, 550 F. 3d 1176, 1178 (2008) (per
curiam).
The rule challenged
here—the Transport Rule—is EPA’s response to the
D. C. Circuit’s North Carolina decision. Finalized in
August 2011, the Transport Rule curtails NOX and SO2 emissions of
27 upwind States to achieve downwind attainment of three different
NAAQS: the two 1997 NAAQS previously addressed by CAIR, and the
2006 NAAQS for PM2.5 levels measured on a daily basis. See 76 Fed.
Reg. 48208–48209.
Under the Transport
Rule, EPA employed a “two-step approach” to determine
when upwind States “contribute[d] significantly to
nonattainment,” id., at 48254, and therefore in
“amounts” that had to be eliminated. At step one,
called the “screening” analysis, the Agency excluded as
de minimis any upwind State that contributed less than one percent
of the three NAAQS[
3] to any
downwind State “receptor,” a location at which EPA
measures air quality. See id., at 48236–48237.[
4] If all of an upwind State’s
contributions fell below the one-percent threshold, that State
would be considered not to have “contribute[d]
signifi-cantly” to the nonattainment of any downwind State.
Id., at 48236. States in that category were screened out and
exempted from regulation under the rule.
The remaining States
were subjected to a second inquiry, which EPA called the
“control” analysis. At this stage, the Agency sought to
generate a cost-effective allocation of emission reductions among
those upwind States “screened in” at step one.
The control analysis
proceeded this way. EPA first calculated, for each upwind State,
the quantity of emissions the State could eliminate at each of
several cost thresholds. See id., at 48248–48249. Cost for
these purposes is measured as cost per ton of emissions prevented,
for instance, by installing scrubbers on powerplant
smokestacks.[
5] EPA estimated,
for example, the amount each upwind State’s NOX emissions
would fall if all pollution sources within each State employed
every control measure available at a cost of $500 per ton or less.
See id., at 48249–48251. The Agency then repeated that
analysis at ascending cost thresholds. See ibid.[
6]
Armed with this
information, EPA conducted complex modeling to establish the
combined effect the upwind reductions projected at each cost
threshold would have on air quality in downwind States. See id., at
48249. The Agency then identified “significant cost
threshold[s],” points in its model where a “noticeable
change occurred in downwind air quality, such as . . .
where large upwind emission reductions become available because a
certain type of emissions control strategy becomes
cost-effective.” Ibid. For example, reductions of NOX
sufficient to resolve or significantly curb downwind air quality
problems could be achieved, EPA determined, at a cost threshold of
$500 per ton (applied uniformly to all regulated upwind States).
“Moving beyond the $500 cost threshold,” EPA concluded,
“would result in only minimal additional . . .
reductions [in emissions].” Id., at 48256.[
7]
Finally, EPA translated
the cost thresholds it had se-lected into amounts of emissions
upwind States would be required to eliminate. For each regulated
upwind State, EPA created an annual emissions “budget.”
These budgets represented the quantity of pollution an upwind State
would produce in a given year if its in-state sources implemented
all pollution controls available at the chosen cost thresholds. See
id., at 48249.[
8] If
EPA’s projected improvements to downwind air quality were to
be realized, an upwind State’s emissions could not exceed the
level this budget allocated to it, subject to certain adjustments
not relevant here.
Taken together, the
screening and control inquiries defined EPA’s understanding
of which upwind emissions were within the Good Neighbor
Provision’s ambit. In short, under the Transport Rule, an
upwind State “contribute[d] significantly” to downwind
nonattainment to the extent its exported pollution both (1)
produced one percent or more of a NAAQS in at least one downwind
State (step one) and (2) could be eliminated cost-effectively, as
determined by EPA (step two). See id., at 48254. Upwind States
would be obliged to eliminate all and only emissions meeting both
of these criteria.[
9]
For each State
regulated by the Transport Rule, EPA contemporaneously promulgated
a FIP allocating that State’s emission budget among its
in-state sources. See id., at 48271, 48284–48287.[
10] For each of these States, EPA
had determined that the State had failed to submita SIP adequate
for compliance with the Good Neighbor Provision. These
determinations regarding SIPs became final after 60 days, see 42
U. S. C. §7607(b)(1)(2006 ed., Supp. V ), and
many went unchallenged.[
11]
EPA views the SIP determinations as having triggered its statutory
obligation to promulgate a FIP within two years, see §7410(c),
a view contested by respondents, see Part II, infra.
D
A group of state and
local governments (State respondents), joined by industry and labor
groups (Industry respondents), petitioned for review of the
Transport Rule in the U. S. Court of Appeals for the
D. C. Circuit. Over the dissent of Judge Rogers, the Court of
Appeals vacated the rule in its entirety. See 696 F. 3d 7, 37
(2012).
EPA’s actions,
the appeals court held, exceeded the Agency’s statutory
authority in two respects. By promulgating FIPs before giving
States a meaningful opportunity to adopt their own implementation
plans, EPA had, in the court’s view, upset the CAA’s
division of responsibility between the States and the Federal
Government. In the main, the Court of Appeals acknowledged,
EPA’s FIP authority is triggered at the moment the Agency
disapproves a SIP. See id., at 30. Thus, when a State proposes a
SIP inadequate to achieve a NAAQS, EPA could promulgate a FIP
immediately after disapproving that SIP. See id., at 32.
But the Court of
Appeals ruled that a different regime applies to a State’s
failure to meet its obligations under the Good Neighbor Provision.
While a NAAQS was a “clear numerical target,” a
State’s good neighbor obligation remained “nebulous and
unknown,” the court observed, until EPA calculated the
State’s emission budget. Ibid. Without these budgets, the
Court of Appeals said, upwind States would be compelled to take a
“stab in the dark” at calculating their own significant
contribution to interstate air pollution. Id., at 35. The
D. C. Circuit read the Act to avoid putting States in this
position: EPA had an implicit statutory duty, the court held, to
give upwind States a reasonable opportunity to allocate their
emission budgets among in-state sources before the Agency’s
authority to issue FIPs could be triggered. Id., at 37.
The D. C. Circuit
also held that the Agency’s two-part interpretation of the
Good Neighbor Provision ignored three “red lines
. . . cabin[ing the] EPA’s authority.” Id.,
at 19. First, the D. C. Circuit interpreted the Good Neighbor
Provision to require upwind States to reduce emissions in “a
manner proportional to their contributio[n]” to pollution in
downwind States. Id., at 21. The Transport Rule, however, treated
all regulated upwind States alike, regardless of their relative
contribution to the overall problem. See id., at 23. It required
all upwind States “screened in” at step one to reduce
emissions in accord with the uniform cost thresholds set during the
step two control analysis. Imposing these uniform cost thresholds,
the Court of Appeals observed, could force some upwind States to
reduce emissions by more than their “fair share.” Id.,
at 27.
According to the Court
of Appeals, EPA had also failed to ensure that the Transport Rule
did not mandate up-wind States to reduce pollution unnecessarily.
The Good Neighbor Provision, the D. C. Circuit noted,
“targets [only] those emissions from upwind States that
‘contribute significantly to
nonattainment’ ” of a NAAQS in downwind States.
Id., at 22. Pollution reduction beyond that goal was
“unnecessary over-control,” outside the purview of the
Agency’s statutory mandate. Ibid. Because the emission
budgets were calculated by reference to cost alone, the court
concluded that EPA had done nothing to guard against, or even
measure, the “over-control” potentially imposed by the
Transport Rule. See ibid.
Finally, by deciding,
at the screening analysis, that upwind contributions below the
one-percent threshold were insignificant, EPA had established a
“floor” on the Agency’s authority to act. See
id., at 20, and n. 13. Again pointing to the rule’s
reliance on costs, the Court of Appeals held that EPA had failed to
ensure that upwind States were not being forced to reduce emissions
below the one-percent threshold. See ibid.
In dissent, Judge
Rogers criticized the majority for deciding two questions that were
not, in her view, properly before the court. See id., at
40–46, 51–58. First, she addressed the majority’s
insistence that FIPs abide a State’s opportunity to allocate
its emission budget among in-state sources. She regarded the
respondents’ plea to that effect as an untimely attack on
EPA’s previous SIP disapprovals. See id., at 40–46.
Second, in Judge Rogers’ assessment, the respondents had
failed to raise their substantive objections to the Transport Rule
with the specificity necessary to preserve them for review. See
id., at 51–58. On the merits, Judge Rogers found nothing in
the Act to require, or even suggest, that EPA must quan-tify a
State’s good neighbor obligations before it promulgated a
FIP. See id., at 46–51. She also disagreed with the
court’s conclusion that the Transport Rule unreasonably
interpreted the Act. See id., at 58–60.
We granted certiorari
to decide whether the D. C. Circuit had accurately construed
the limits the CAA places on EPA’s authority. See 570
U. S. ___ (2013).
II
A
Once EPA has
calculated emission budgets, the D. C. Circuit held, the
Agency must give upwind States the opportunity to propose SIPs
allocating those budgets among in-state sources before issuing a
FIP. 696 F. 3d, at 37. As the State respondents put it, a FIP
allocating a State’s emission budget “must issue after
EPA has quantified the States’ good-neighbor obligations [in
an emission budget] and given the States a reasonable opportunity
to meet those obligations in SIPs.” Brief for State
Respondents 20.
Before reaching the
merits of this argument, we first reject EPA’s threshold
objection that the claim is untimely. According to the Agency, this
argument—and the D. C. Circuit’s opinion accepting
it—rank as improper collateral attacks on EPA’s prior
SIP disapprovals. As earlier recounted, see supra, at 9–10,
EPA, by the time it issued the Transport Rule, had determined that
each regulated upwind State had failed to submit a SIP adequate to
satisfy the Good Neighbor Provision. Many of those determinations,
because unchallenged, became final after 60 days, see 42
U. S. C. §7607(b)(1), and did so before the
petitions here at issue were filed. EPA argues that the Court
cannot question exercise of the Agency’s FIP authority
without subjecting these final SIP disapprovals to untimely
review.
We disagree. The
gravamen of the State respondents’ challenge is not that
EPA’s disapproval of any particular SIP was erroneous.
Rather, respondents urge that, notwithstanding these disapprovals,
the Agency was obliged to grant an upwind State a second
opportunity to promul-gate adequate SIPs once EPA set the
State’s emission budget. This claim does not depend on the
validity of the prior SIP disapprovals. Even assuming the
legitimacy of those disapprovals, the question remains whether EPA
was required to do more than disapprove a SIP, as the State
respondents urge, to trigger the Agency’s statutory authority
to issue a FIP.[
12]
B
Turning to the
merits, we hold that the text of the statute supports EPA’s
position. As earlier noted, see supra, at 4–5, the CAA sets a
series of precise deadlines to which the States and EPA must
adhere. Once EPA issues any new or revised NAAQS, a State has three
years to adopt a SIP adequate for compliance with the Act’s
requirements. See 42 U. S. C. §7410(a)(1). Among
those requirements is the Act’s mandate that SIPs
“shall” include provisions sufficient to satisfy the
Good Neighbor Provision. §7410(a)(2).
If EPA determines a SIP
to be inadequate, the Agency’s mandate to replace it with a
FIP is no less absolute:
“[EPA] shall
promulgate a [FIP] at any time within 2 years after the
[Agency]
“(A) finds that
a State has failed to make a required submission or finds that the
plan or plan revision submitted by the State does not satisfy the
minimum [relevant] criteria . . . , or
“(B) disapproves
a [SIP] in whole or in part,
“unless the State corrects the deficiency,
and [EPA] approves the plan or plan revision, before the [Agency]
promulgates such [FIP].” §7410(c)(1).
In other words, once EPA has found a SIP
inadequate, the Agency has a statutory duty to issue a FIP
“at any time” within two years (unless the State first
“corrects the deficiency,” which no one contends
occurred here).
The D. C. Circuit,
however, found an unwritten exception to this strict time
prescription for SIPs aimed at implementing the Good Neighbor
Provision. Expecting any one State to develop a
“comprehensive solution” to the “collective
problem” of interstate air pollution without first receiving
EPA’s guidance was, in the Court of Appeals’
assessment, “set[ting] the States up to fail.” 696
F. 3d, at 36–37. The D. C. Circuit therefore
required EPA, after promulgating each State’s emission
budget, to give the State a “reasonable” period of time
to propose SIPs implementing its budget. See id., at 37.
However sensible (or
not) the Court of Appeals’ position,[
13] a reviewing court’s “task is to
apply the text [of the statute], not to improve upon it.”
Pavelic & LeFlore v. Marvel Entertainment Group, Div. of
Cadence Industries Corp., 493 U. S. 120, 126 (1989) . Nothing
in the Act dif-ferentiates the Good Neighbor Provision from the
several other matters a State must address in its SIP. Rather, the
statute speaks without reservation: Once a NAAQS has been issued, a
State “shall” propose a SIP within three years,
§7410(a)(1), and that SIP “shall” include, among
other components, provisions adequate to satisfy the Good Neighbor
Provision, §7410(a)(2).
Nor does the Act
condition the duty to promulgate a FIP on EPA’s having first
quantified an upwind State’s good neighbor obligations. As
Judge Rogers observed in her dissent from the D. C.
Circuit’s decision, the Act does not require EPA to furnish
upwind States with information of any kind about their good
neighbor obligations before a FIP issues. See 696 F. 3d, at
47. Instead, a SIP’s failure to satisfy the Good Neighbor
Provision, without more, triggers EPA’s obligation to issue a
federal plan within two years. §7410(c). After EPA has
disapproved a SIP, the Agency can wait up to two years to issue a
FIP, during which time the State can “correc[t] the
deficiency” on its own. Ibid. But EPA is not obliged to wait
two years or postpone its action even a single day: The Act
empowers the Agency to promulgate a FIP “at any time”
within the two-year limit. Ibid. Carving out an exception to the
Act’s precise deadlines, as the D. C. Circuit did,
“rewrites a decades-old statute whose plain text and
structure establish a clear chronology of federal and State
responsibilities.” 696 F. 3d, at 47 (Rogers, J.,
dissenting).
The practical
difficulties cited by the Court of Appeals do not justify departure
from the Act’s plain text. See Barnhart v. Sigmon Coal Co.,
534 U. S. 438 –462 (2002) (We “must presume that a
legislature says in a statute what it means and means in a statute
what it says there.” (internal quotation marks omitted)).
When Congress elected to make EPA’s input a prerequisite to
state action under the Act, it did so expressly. States developing
vehicle inspection and maintenance programs under the CAA, for
example, must await EPA guidance before issuing SIPs. 42
U. S. C. §7511a(c)(3)(B). A State’s obligation
to adopt a SIP, moreover, arises only after EPA has first set the
NAAQS the State must meet. §7410(a)(1). Had Congress intended
similarly to defer States’ discharge of their obligations
under the Good Neighbor Provision, Congress, we take it, would have
included a similar direction in that section. See Jama v.
Immigration and Customs Enforcement, 543 U. S. 335, 341 (2005)
(“We do not lightly assume that Congress has omitted from its
adopted text requirements that it nonetheless intends to apply, and
our reluctance is even greater when Congress has shown elsewhere in
the same statute that it knows how to make such a requirement
manifest.”).
In short, nothing in
the statute places EPA under an obligation to provide specific
metrics to States before they undertake to fulfill their good
neighbor obligations. By altering the schedule Congress provided
for SIPs and FIPs, the D. C. Circuit stretched out the
process. It allowed a delay Congress did not order and placed an
information submission obligation on EPA Congress did not impose.
The D. C. Circuit, we hold, had no warrant thus to revise the
CAA’s action-ordering prescriptions.
C
At oral argument, the
State respondents emphasized EPA’s previous decisions, in the
NOX SIP Call and CAIR, to quantify the emission reductions required
of upwind States before the window to propose a SIP closed. See Tr.
of Oral Arg. 37–39, 42–43, 45–46. In their view,
by failing to accord States a similar grace period after issuing
States’ emission budgets, EPA acted arbitrarily. See
ibid.
Whatever pattern the
Agency followed in its NOX SIP call and CAIR proceedings, EPA
retained discretion to alter its course provided it gave a
reasonable explanation for doing so. Motor Vehicle Mfrs. Assn. of
United States, Inc. v. State Farm Mut. Automobile Ins. Co., 463
U. S. 29, 42 (1983) . The Agency presented such an explanation
in the Transport Rule. As noted, see supra, at 6, the D. C.
Circuit’s North Carolina decision admonished EPA to act with
dispatch in amending or replacing CAIR, the Transport Rule’s
predecessor. See 550 F. 3d, at 1178 (warning EPA that the stay
of the court’s decision to vacate CAIR would not persist
“indefinite[ly]”). Given North Carolina’s stress
on expeditious action to cure the infir-mities the court identified
in CAIR, EPA thoughtit “[in]appropriate to establish [the]
lengthy transition period” entailed in allowing States time
to propose new or amended SIPs implementing the Transport Rule
emission budgets. See 76 Fed. Reg. 48220 (citing North Carolina,
550 F. 3d 1176). Endeavoring to satisfy the D. C.
Circuit’s directive, EPA acted speedily, issuing FIPs
contemporaneously with the Transport Rule. In light of the firm
deadlines imposed by the Act, which we hold the D. C. Circuit
lacked authority to alter, we cannot condemn EPA’s decision
as arbitrary or capricious.[
14]
III
A
The D. C.
Circuit also held that the Transport Rule’s two-step
interpretation of the Good Neighbor Provision conflicts with the
Act. Before addressing this holding, we take up a jurisdictional
objection raised by EPA.
The CAA directs that
“[o]nly an objection to a rule . . . raised with
reasonable specificity during the period for public comment
. . . may be raised during judicial review.” 42
U. S. C. §7607(d)(7)(B). Respondents failed to state
their objections to the Transport Rule during the comment period
with the “specificity” required for preservation, EPA
argues. See Brief for Federal Petitioners 34–42. This failure
at the administrative level, EPA urges, forecloses judicial review.
Id., at 34.
Assuming, without
deciding, that respondents did not meet the Act’s
“reasonable specificity” requirement during the comment
period, we do not regard that lapse as
“jurisdictional.” This Court has cautioned against
“profligate use” of the label
“jurisdictional.” Sebelius v. Auburn Regional Medical
Center, 568 U. S. ___, ___ (2013) (slip op., at 6). A rule may
be “mandatory,” yet not “jurisdictional,”
we have explained. See Arbaugh v. Y & H Corp., 546 U. S.
500, 510 (2006) . Section 7607(d)(7)(B), we hold, is of that
character. It does not speak to a court’s authority, but only
to a party’s procedural obligations. See Kontrick v. Ryan,
540 U. S. 443, 455 (2004) . Had EPA pursued the
“reasonable specificity” argument vigorously before the
D. C. Circuit, we would be obligated to address the merits of
the argument. See Gonzalez v. Thaler, 565 U. S. ___, ___
(2012) (slip op., at 10). But EPA did not press the argument
unequivocally. Before the D. C. Circuit, it indicated only
that the “reasonable specificity” prescription might
bar judicial review. Brief for Respondent EPA et al. in No.
11–1302 (CADC), p. 30. See also id., at 32. We therefore
do not count the prescription an impassable hindrance to our
adjudication of the respondents’ attack on EPA’s
interpretation of the Transport Rule. We turn to that attack
mindful of the importance of the issues respondents raise to the
ongoing implementation of the Good Neighbor Provision.
B
We routinely accord
dispositive effect to an agency’s reasonable interpretation
of ambiguous statutory language. Chevron U. S. A. Inc. v.
Natural Resources Defense Council, Inc., 467 U. S. 837 (1984)
, is the pathmarking decision, and it bears a notable resemblance
to the cases before us. Chevron concerned EPA’s definition of
the term “source,” as used in the 1977 Amendments to
the CAA. Id., at 840, n. 1. Those amendments placed additional
restrictions on companies’ liberty to add new pollution
“sources” to their factories. See id., at 840. Although
“source” might have been interpreted to refer to an
individual smokestack, EPA construed the term to refer to an entire
plant, thereby “treat[ing] all of the pollution-emitting
devices within the [plant] as though they were encased within a
single ‘bubble.’ ” Ibid. Under the
Agency’s interpretation, a new pollution-emitting device
would not subject a plant to the additional restrictions if the
“alteration [did] not increase the total emissions [produced
by] the plant.” Ibid.
This Court held
EPA’s interpretation of “source” a reasonable
construction of an ambiguous statutory term. When “Congress
has not directly addressed the precise [interpretative] question at
issue,” we cautioned, a reviewing court cannot “simply
impose its own construction o[f] the statute.” Id., at 843.
Rather, the agency is charged with filling the “gap left
open” by the ambiguity. Id., at 866. Because
“ ‘a full understanding of the force of the
statutory policy . . . depend[s] upon more than ordinary
knowledge’ ” of the situation, the administering
agency’s construction is to be accorded “controlling
weight unless . . . arbitrary, capricious, or manifestly
contrary to the statute.” Id., at 844 (quoting United States
v. Shimer, 367 U. S. 374, 382 (1961) ). Determining that none
of those terms fit EPA’s interpretation of
“source,” the Court deferred to the Agency’s
judgment.
We conclude that the
Good Neighbor Provision delegates authority to EPA at least as
certainly as the CAA provisions involved in Chevron. The statute
requires States to eliminate those “amounts” of
pollution that “contribute significantly to
nonattainment” in downwind States. 42 U. S. C.
§7410(a)(2)(D)(i) (emphasis added). Thus, EPA’s
task[
15] is to reduce upwind
pollution, but only in “amounts” that push a downwind
State’s pollution concentrations above the relevant NAAQS. As
noted earlier, however, the nonattainment of downwind States
results from the collective and interwoven contributions of
multiple upwind States. See supra, at 3. The statute therefore
callsupon the Agency to address a thorny causation problem: How
should EPA allocate among multiple contributing up-wind States
responsibility for a downwind State’s excess pollution?
A simplified example
illustrates the puzzle EPA faced. Suppose the Agency sets a NAAQS,
with respect to a particular pollutant, at 100 parts per billion
(ppb), and that the level of the pollutant in the atmosphere of
downwind State A is 130 ppb. Suppose further that EPA has
determined that each of three upwind States—X, Y, and
Z—contributes the equivalent of 30 ppb of the relevant
pollutant to State A’s airspace. The Good Neighbor Provision,
as just observed, prohibits only upwind emissions that contribute
significantly to downwind nonattainment. EPA’s authority
under the provision is therefore limited to eliminating a total of
30 ppb,[
16] i.e., the
overage caused by the collective contribution of States X, Y, and
Z.[
17]
How is EPA to divide
responsibility among the three States? Should the Agency allocate
reductions proportionally (10 ppb each), on a per capita basis, on
the basis of the cost of abatement, or by some other metric? See
Brief for Federal Petitioners 50 (noting EPA’s consideration
of different approaches). The Good Neighbor Provision does not
answer that question for EPA. Cf. Chevron, 467 U. S., at 860
(“[T]he language of [the CAA] simply does not compel any
given interpretation of the term
‘source.’ ”). Under Chevron, we read
Congress’ silence as a delegation of authority to EPA to
select from among reasonable options. See United States v. Mead
Corp., 533 U. S. 218, 229 (2001) .[
18]
Yet the Court of
Appeals believed that the Act speaks clearly, requiring EPA to
allocate responsibility for reducing emissions in “a manner
proportional to” each State’s
“contributio[n]” to the problem. 696 F. 3d, at 21.
Nothing in the text of the Good Neighbor Provision propels EPA down
this path. Understandably so, for as EPA notes, the D. C.
Circuit’s proportionality approach could scarcely be
satisfied in practice. See App. in No. 11–1302 etc. (CADC),
p. 2312 (“[W]hile it is possible to determine an
emission reduction percentage if there is a single downwind
[receptor], most upwind states contribute to multiple downwind
[receptors] (in multiple states) and would have a different
reduction percentage for each one.”).
To illustrate, consider
a variation on the example set out above. Imagine that States X and
Y now contribute air pollution to State A in a ratio of one to
five, i.e., State Y contributes five times the amount of pollution
to State A than does State X. If State A were the only downwind
State to which the two upwind States contributed, the D. C.
Circuit’s proportionality requirement would be easy to meet:
EPA could require State Y to reduce its emissions by five times the
amount demanded of State X.
The realities of
interstate air pollution, however, are not so simple. Most upwind
States contribute pollution to multiple downwind States in varying
amounts. See 76 Fed. Reg. 48239–48246. See also Brief for
Respondent Calpine Corp. et al. in Support of Petitioners
48–49 (offering examples). Suppose then that States X and Y
also contribute pollutants to a second downwind State (State B),
this time in a ratio of seven to one. Though State Y contributed a
relatively larger share of pollution to State A, with respect to
State B, State X is the greater offender. Following the
proportionality approach with respect to State B would demand that
State X reduce its emissions by seven times as much as State Y.
Recall, however, that State Y, as just hypothesized, had to effect
five times as large a reduction with respect to State A. The Court
of Appeals’ proportionality edict with respect to both State
A and State B appears to work neither mathematically nor in
practical application. Proportionality as to one down-wind State
will not achieve proportionality as to others. Quite the opposite.
And where, as is generally true, upwind States contribute pollution
to more than two downwind receptors, proportionality becomes all
the more elusive.
Neither the D. C.
Circuit nor respondents face up to this problem. The dissent, for
its part, strains to give meaning to the D. C. Circuit’s
proportionality constraint as applied to a world in which multiple
upwind States contribute emissions to multiple downwind locations.
In the dissent’s view, upwind States must eliminate emissions
by “whatever minimum amount reduces” their share of the
overage in each and every one of the downwind States to which they
are linked. See post, at 8. In practical terms, this means each
upwind State will be required to reduce emissions by the amount
necessary to eliminate that State’s largest downwind
contribution. The dissent’s formulation, however, does not
account for the combined and cumu-lative effect of each upwind
State’s reductions on attainment in multiple downwind
locations. See ibid. (“Under a proportional-reduction
approach, State X would be required to eliminate emissions of that
pollutant by whatever minimum amount reduces both State A’s
level by 0.2 unit and State B’s by 0.7 unit.” (emphasis
added)). The result would be costly overregulation unnecessary to,
indeedin conflict with, the Good Neighbor Provision’s goal of
attainment.[
19]
In response, the
dissent asserts that EPA will “simply be required to make
allowance for” the overregulation caused by its
“proportional-reduction” approach. Post, at 11. What
criterion should EPA employ to determine which States will have to
make those “allowance[s]” and by how much? The dissent
admits there are “multiple ways” EPA might answer those
questions. Ibid. But proportionality cannot be one of those ways,
for theproportional-reduction approach is what led to the
overregulation in the first place. And if a nonproportional
approach can play a role in setting the final allocation of
reduction obligations, then it is hardly apparent why EPA, free to
depart from proportionality at the back end, cannot do so at the
outset.
Persuaded that the Good
Neighbor Provision does not dictate the particular allocation of
emissions among contributing States advanced by the D. C.
Circuit, we must next decide whether the allocation method chosen
by EPA is a “permissible construction of the statute.”
Chevron, 467 U. S., at 843. As EPA interprets the statute,
upwind emissions rank as “amounts [that] . . .
contribute significantly to nonattainment” if they (1)
constitute one percent or more of a relevant NAAQS in a
nonattaining downwind State and (2) can be eliminated under the
cost threshold set by the Agency. See 76 Fed. Reg. 48254. In other
words, to identify which emissions were to be eliminated, EPA
considered both the magnitude of upwind States’ contributions
and the cost associated with eliminating them.
The Industry
respondents argue that, however EPA ultimately divides
responsibility among upwind States, the final calculation cannot
rely on costs. The Good Neighbor Provision, respondents and the
dissent emphasize, “requires each State to prohibit only
those ‘amounts’ of air pollution emitted within the
State that ‘contribute significantly’ to another
State’s nonattaintment.” Brief for Industry Respondents
23 (emphasis added). See also post, at 6. The cost of preventing
emissions, they urge, iswholly unrelated to the actual
“amoun[t]” of air pollution an upwind State
contributes. Brief for Industry Respondents 23. Because the
Transport Rule considers costs, respondents argue, “States
that contribute identical ‘amounts’ . . . may
be deemed [by EPA] to have [made] substantially different”
contributions. Id., at 30.
But, as just explained,
see supra, at 21–22, the Agency cannot avoid the task of
choosing which among equal “amounts” to eliminate. The
Agency has chosen, sensibly in our view, to reduce the amount
easier, i.e., less costly, to eradicate, and nothing in the text of
the Good Neighbor Provision precludes that choice.
Using costs in the
Transport Rule calculus, we agree with EPA, also makes good sense.
Eliminating those amounts that can cost-effectively be reduced is
an efficient and equitable solution to the allocation problem the
Good Neighbor Provision requires the Agency to address. Efficient
because EPA can achieve the levels of attainment, i.e., of emission
reductions, the proportional approach aims to achieve, but at a
much lower overall cost. Equita-ble because, by imposing uniform
cost thresholds on regulated States, EPA’s rule subjects to
stricter regulation those States that have done relatively less in
the past to control their pollution. Upwind States that have not
yet implemented pollution controls of the same stringency as their
neighbors will be stopped from free riding on their
neighbors’ efforts to reduce pollution. They will have to
bring down their emissions by installing devices of the kind in
which neighboring States have already invested.
Suppose, for example,
that the industries of upwind State A have expended considerable
resources installing modern pollution-control devices on their
plants. Factories in upwind State B, by contrast, continue to run
old, dirty plants. Yet, perhaps because State A is more populous
and therefore generates a larger sum of pollution overall, the two
States’ emissions have equal effects on downwind attainment.
If State A and State B are required to eliminate emissions
proportionally (i.e., equally), sources in State A will be
compelled to spend far more per ton of reductions because they have
already utilized lower cost pollution controls. State A’s
sources will also have to achieve greater reductions than would
have been required had they not made the cost-effective reductions
in the first place. State A, in other words, will be tolled for
having done more to reduce pollution in the past.[
20] EPA’s cost-based allocation
avoids these anomalies.
Obligated to require
the elimination of only those “amounts” of pollutants
that contribute to the nonattainment of NAAQS in downwind States,
EPA must decide how to differentiate among the otherwise like
contributions of multiple upwind States. EPA found decisive the
difficulty of eliminating each “amount,” i.e., the cost
incurred in doing so. Lacking a dispositive statutory instruction
to guide it, EPA’s decision, we conclude, is a
“reasonable” way of filling the “gap left open by
Congress.” Chevron, 467 U. S., at 866.[
21]
C
The D. C.
Circuit stated two further objections to EPA’s cost-based
method of defining an upwind State’s contribution. Once a
State was screened in at step one of EPA’s analysis, its
emission budget was calculated solely with reference to the uniform
cost thresholds the Agency selected at step two. The Transport Rule
thus left open thepossibility that a State might be compelled to
reduce emissions beyond the point at which every affected downwind
State is in attainment, a phenomenon the Court of Appeals termed
“over-control.” 696 F. 3d, at 22; see supra, at
12. Second, EPA’s focus on costs did not foreclose, as the
D. C. Circuit accurately observed, the possibility that an
upwind State would be required to reduce its emissions by so much
that the State no longer contributed one per-cent or more of a
relevant NAAQS to any downwind State. This would place the State
below the mark EPA had set, during the screening phase, as the
initial threshold of “significan[ce].” See id., at 20,
and n. 13.
We agree with the Court
of Appeals to this extent: EPA cannot require a State to reduce its
output of pollution by more than is necessary to achieve attainment
in every downwind State or at odds with the one-percent threshold
the Agency has set. If EPA requires an upwind State to reduce
emissions by more than the amount necessary to achieve attainment
in every downwind State to which it is linked, the Agency will have
overstepped its authority, under the Good Neighbor Provision, to
eliminate those “amounts [that] contribute . . . to
nonattainment.” Nor can EPA demand reductions that would
drive an upwind State’s contribution to every downwind State
to which it is linked below one percent of the relevant NAAQS.
Doing so would be counter to step one of the Agency’s
interpretation of the Good Neighbor Provision. See 76 Fed. Reg.
48236 (“[S]tates whose contributions are below th[e]
thresholds do not significantly contribute to nonattainment
. . . of the relevant NAAQS.”).
Neither possibility,
however, justifies wholesale invalidation of the Transport Rule.
First, instances of “over-control” in particular
downwind locations, the D. C. Circuit acknowledged, see 696
F. 3d, at 22, may be incidental to reductions necessary to
ensure attainment elsewhere. Because individual upwind States often
“contribute significantly” to nonattainment in multiple
downwind locations, the emissions reduction required to bring one
linked downwind State into attainment may well be large enough to
push other linked downwind States over the attainment
line.[
22] As the Good
Neighbor Provision seeks attainment in every downwind State,
however, exceeding attainment in one State cannot rank as
“over-control” unless unnecessary to achieving
attainment in any downwind State. Only reductions unnecessary to
downwind attainment anywhere fall outside the Agency’s
statutory authority.[
23]
Second, while EPA has a
statutory duty to avoid over-control, the Agency also has a
statutory obligation to avoid “under-control,” i.e., to
maximize achievement of attainment downwind. For reasons earlier
explained, see supra, at 3–4, a degree of imprecision is
inevitable in tackling the problem of interstate air pollution.
Slight changes in wind patterns or energy consumption, for example,
may vary downwind air quality in ways EPA might not have
anticipated. The Good Neighbor Provision requires EPA to seek
downwind attainment of NAAQS notwithstanding the uncertainties.
Hence, some amount of over-control, i.e., emission budgets that
turn out to be more demanding than necessary, would not be
surprising. Required to balance the possibilities of under-control
and over-control, EPA must have leeway in fulfilling its statutory
mandate.
Finally, in a
voluminous record, involving thousands of upwind-to-downwind
linkages, respondents point to only a few instances of
“unnecessary” emission reductions, and even those are
contested by EPA. Compare Brief for Industry Respondents 19 with
Reply Brief for Federal Petitioners 21–22. EPA, for its part,
offers data, contested by respondents, purporting to show that few
(if any) upwind States have been required to limit emissions below
the one-percent threshold of significance. Compare Brief for
Federal Petitioners 37, 54–55, with Brief for Industry
Respondents 40.
If any upwind State
concludes it has been forced to regulate emissions below the
one-percent threshold or beyond the point necessary to bring all
downwind States into attainment, that State may bring a
particularized, as-applied challenge to the Transport Rule, along
with any other as-applied challenges it may have. Cf. Babbitt v.
Sweet Home Chapter, Communities for Great Ore., 515 U. S. 687
–700 (1995) (approving agency’s reasonable
interpretation of statute despite possibility of improper
applications); American Hospital Assn. v. NLRB, 499 U. S. 606,
619 (1991) (rejecting facial challenge to National Labor Relations
Board rule despite possible arbitrary applications). Satisfied that
EPA’s cost-based methodol-ogy, on its face, is not
“arbitrary, capricious, or manifestly contrary to the
statute,” Chevron, 467 U. S., at 844, we uphold the
Transport Rule. The possibility that the rule, in uncommon
particular applications, might exceed EPA’s statutory
authority does not warrant judicial condemnation of the rule in its
entirety.
In sum, we hold that
the CAA does not command that States be given a second opportunity
to file a SIP after EPA has quantified the State’s interstate
pollution obligations. We further conclude that the Good Neighbor
Provision does not require EPA to disregard costs and consider
exclusively each upwind State’s physically proportionate
responsibility for each downwind air quality problem. EPA’s
cost-effective allocation of emission reductions among upwind
States, we hold, is a permissible, work-able, and equitable
interpretation of the Good Neighbor Provision.
* * *
For the reasons
stated, the judgment of the United States Court of Appeals for the
D. C. Circuit is reversed, and the cases are remanded for
further proceedings consistent with this opinion.
It is so ordered.
Justice Alito took no
part in the consideration or decision of these cases.