American Electric Power Co. v. Connecticut

OPINION OF THE COURT AMERICAN ELEC. POWER CO. V. CONNECTICUT 564 U. S. ____ (2011) SUPREME COURT OF THE UNITED STATES NO. 10-174 AMERICAN ELECTRIC POWER COMPANY, INC., et al.,
PETITIONERS v. CONNECTICUT et al.

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

															[June 20, 2011]

															   Justice Ginsburg delivered the
opinion of the Court.

															   We address in this opinion the
question whether the plaintiffs (several States, the city of New
York, and three private land trusts) can maintain federal common
law public nuisance claims against carbon-dioxide emitters (four
private power companies and the federal Tennessee Valley
Authority). As relief, the plaintiffs ask for a decree setting
carbon-dioxide emissions for each defendant at an initial cap, to
be further reduced annually. The Clean Air Act and the
Environmental Protection Agency action the Act authorizes, we hold,
displace the claims the plaintiffs seek to pursue.

															I

															   In Massachusetts v. EPA , 549 U.
S. 497 (2007), this Court held that the Clean Air Act, 42 U. S.
C. §7401 et seq. , authorizes federal regulation of
emissions of carbon dioxide and other greenhouse gases.
“[N]aturally present in the atmosphere and … also emitted by human
activities,” greenhouse gases are so named because they “trap …
heat that would otherwise escape from the [Earth’s] atmosphere, and
thus form the greenhouse effect that helps keep the Earth warm
enough for life.” 74 Fed. Reg. 66499 (2009).[ Footnote 1 ] Massachusetts held that the
Environmental Protection Agency (EPA) had misread the Clean Air Act
when it denied a rulemaking petition seeking controls on greenhouse
gas emissions from new motor vehicles. 549 U. S., at 510–511.
Greenhouse gases, we determined, qualify as “air pollutant[s]”
within the meaning of the governing Clean Air Act provision, id. , at 528–529 (quoting §7602(g)); they are therefore
within EPA’s regulatory ken. Because EPA had authority to set
greenhouse gas emission standards and had offered no “reasoned
explanation” for failing to do so, we concluded that the agency had
not acted “in accordance with law” when it denied the requested
rulemaking. Id. , at 534–535 (quoting §7607(d)(9)(A)).

															   Responding to our decision in Massachusetts , EPA un-dertook greenhouse gas regulation.
In December 2009, the agency concluded that greenhouse gas
emissions from motor vehicles “cause, or contribute to, air
pollution which may reasonably be anticipated to endanger public
health or welfare,” the Act’s regulatory trigger. §7521(a)(1); 74
Fed. Reg. 66496. The agency observed that “atmospheric greenhouse
gas concentrations are now at elevated and essentially
unprecedented levels,” almost entirely “due to anthropogenic
emissions,” id. , at 66517; mean global temperatures, the
agency continued, demonstrate an “unambiguous warming trend over
the last 100 years,” and particularly “over the past 30 years,” ibid . Acknowledging that not all scientists agreed on the
causes and consequences of the rise in global temperatures, id. , at 66506, 66518, 66523–66524, EPA concluded that
“compelling” evidence supported the “attribution of observed
climate change to anthropogenic” emissions of greenhouse gases, id ., at 66518. Consequent dangers of greenhouse gas
emissions, EPA determined, included increases in heat-related
deaths; coastal inundation and erosion caused by melting icecaps
and rising sea levels; more frequent and intense hurricanes,
floods, and other “extreme weather events” that cause death and
destroy infrastructure; drought due to reductions in mountain
snowpack and shifting precipitation patterns; destruction of
ecosystems supporting animals and plants; and potentially
“significant disruptions” of food production. Id. , at
66524–66535.[ Footnote 2 ]

															   EPA and the Department of Transportation
subsequently issued a joint final rule regulating emissions from
light-duty vehicles, see 75 Fed. Reg. 25324 (2010), and initiated a
joint rulemaking covering medium- and heavy-duty vehicles, see id. , at 74152. EPA also began phasing in requirements that
new or modified “[m]ajor [greenhouse gas] emitting facilities” use
the “best available control technology.” §7475(a)(4); 75 Fed. Reg.
31520–31521. Fin-ally, EPA commenced a rulemaking under §111 of the
Act, 42 U. S. C. §7411, to set limits on greenhouse gas
emissions from new, modified, and existing fossil-fuel fired power
plants. Pursuant to a settlement finalized in March 2011, EPA has
committed to issuing a proposed rule by July 2011, and a final rule
by May 2012. See 75 Fed. Reg. 82392; Reply Brief for Tennessee
Valley Authority 18.

															II

															   The lawsuits we consider here
began well before EPA initiated the efforts to regulate greenhouse
gases just described. In July 2004, two groups of plaintiffs filed
separate complaints in the Southern District of New York against
the same five major electric power companies. The first group of
plaintiffs included eight States[ Footnote 3 ] and New York City, the second joined three
nonprofit land trusts[ Footnote
4 ]; both groups are respondents here. The defendants, now
petitioners, are four private companies[ Footnote 5 ] and the Tennessee Valley Authority, a
federally owned corporation that operates fossil-fuel fired power
plants in several States. According to the complaints, the
defendants “are the five largest emitters of carbon dioxide in the
United States.” App. 57, 118. Their collective annual emissions of
650 million tons constitute 25 percent of emissions from the
domestic electric power sector, 10 percent of emissions from all
domestic human activities, ibid. , and 2.5 percent of all
anthropogenic emissions worldwide, App. to Pet. for Cert. 72a.

															   By contributing to global
warming, the plaintiffs asserted, the defendants’ carbon-dioxide
emissions created a “substantial and unreasonable interference with
public rights,” in violation of the federal common law of
interstate nuisance, or, in the alternative, of state tort law.
App. 103–105, 145–147. The States and New York City alleged that
public lands, infrastructure, and health were at risk from climate
change. App. 88–93. The trusts urged that climate change would
destroy habitats for animals and rare species of trees and plants
on land the trusts owned and conserved. App. 139–145. All
plaintiffs sought injunctive relief requiring each defendant “to
cap

															its carbon dioxide emissions and then reduce them by a specified
percentage each year for at least a decade.” App. 110, 153.

															   The District Court dismissed both suits as
presenting non-justiciable political questions, citing Baker v. Carr , 369 U. S. 186 (1962),
but the Second Circuit reversed, 582 F. 3d 309 (2009). On the
threshold questions, the Court of Appeals held that the suits were
not barred by the political question doctrine, id. , at
332, and that the plaintiffs had adequately alleged Article III
standing, id. , at 349.

															   Turning to the merits, the Second Circuit held
that all plaintiffs had stated a claim under the “federal common
law of nuisance.” Id. , at 358, 371. For this
determination, the court relied dominantly on a series of this
Court’s decisions holding that States may maintain suits to abate
air and water pollution produced by other States or by out-of-state
industry. Id. , at 350–351; see, e.g. , Illinois v. Milwaukee , 406 U. S. 91 , 93, (1972)
( Milwaukee I ) (recognizing right of Illinois to sue in
federal district court to abate discharge of sewage into Lake
Michigan).

															   The Court of Appeals further determined that
the Clean Air Act did not “displace” federal common law. In Milwaukee v. Illinois , 451 U. S. 304 , 316–319
(1981) ( Milwaukee II ), this Court held that Congress had
displaced the federal common law right of action recognized in Milwaukee I by adopting amendments to the Clean Water Act,
33 U. S. C. §1251 et seq. That legislation installed
an all-encompassing regulatory program, supervised by an expert
administrative agency, to deal comprehensively with interstate
water pollution. The legislation itself prohibited the discharge of
pollutants into the waters of the United States without a permit
from a proper permitting authority. Milwaukee II , 451 U.
S., at 310–311 (citing §1311). At the time of the Second Circuit’s
decision, by contrast, EPA had not yet promulgated any rule
regulating greenhouse gases, a fact the court thought dispositive.
582 F. 3d, at 379–381. “Until EPA completes the rulemaking
process,” the court reasoned, “we cannot speculate as to whether
the hypothetical regulation of greenhouse gases under the Clean Air
Act would in fact ‘spea[k] directly’ to the ‘particular issue’
raised here by Plaintiffs.” Id. , at 380.

															   We granted certiorari. 562 U. S. ___
(2010).

															III

															   The petitioners contend that the
federal courts lack au-thority to adjudicate this case. Four
members of the Court would hold that at least some plaintiffs have
Article III standing under Massachusetts , which permitted
a State to challenge EPA’s refusal to regulate greenhouse gas
emissions, 549 U. S., at 520–526; and, further, that no other
threshold obstacle bars review.[ Footnote 6 ] Four members of the Court, adhering to a
dissenting opinion in Massachusetts , 549 U. S., at 535, or
regarding that decision as distinguishable, would hold that none of
the plaintiffs have Article III standing. We therefore affirm, by
an equally divided Court, the Second Circuit’s exercise of
jurisdiction and proceed to the merits. See Nye v. United States , 313 U. S. 33 , 44
(1941).

															IV

															A

															   “There is no federal general
common law,” Erie R. Co. v. Tompkins , 304 U. S. 64 , 78 (1938),
famously recognized. In the wake of Erie , however, a
keener understanding developed. See generally Friendly, In Praise
of Erie —And of the New Federal Common Law, 39 N. Y.
U. L. Rev. 383 (1964). Erie “le[ft] to the states
what ought be left to them,” id. , at 405, and thus
required “federal courts [to] follow state decisions on matters of
substantive law appropriately cognizable by the states,” id. , at 422. Erie also sparked “the emergence of
a federal decisional law in areas of national concern.” Id. , at 405. The “new” federal common law addresses
“subjects within national legislative power where Congress has so
directed” or where the basic scheme of the Constitution so demands. Id. , at 408, n. 119, 421–422. Environmental protection is
undoubtedly an area “within national legislative power,” one in
which federal courts may fill in “statutory interstices,” and, if
necessary, even “fashion federal law.” Id. , at 421–422. As
the Court stated in Milwaukee I : “When we deal with air
and water in their ambient or interstate aspects, there is a
federal common law.” 406 U. S., at 103.

															   Decisions of this Court predating Erie , but compatible with the distinction emerging from
that decision between “general common law” and “specialized federal
common law,” Friendly, supra , at 405, have approved
federal common law suits brought by one State to abate pollution
emanating from another State. See, e.g. , Missouri v. Illinois , 180 U. S. 208 , 241–243
(1901) (permitting suit by Missouri to enjoin Chicago from
discharging untreated sewage into interstate waters); New
Jersey v. City of New York , 283 U. S. 473 , 477,
481–483 (1931) (ordering New York City to stop dumping garbage off
New Jersey coast); Georgia v. Tennessee Copper
Co. , 240 U. S.
650 (1916) (ordering private copper companies to curtail
sulfur-dioxide discharges in Tennessee that caused harm in
Georgia). See also Milwaukee I , 406 U. S., at 107
(post- Erie decision upholding suit by Illinois to abate
sewage discharges into Lake Michigan). The plaintiffs contend that
their right to maintain this suit follows inexorably from that line
of decisions.

															   Recognition that a subject is meet for federal
law governance, however, does not necessarily mean that federal
courts should create the controlling law. Absent a demonstrated
need for a federal rule of decision, the Court has taken “the
prudent course” of “adopt[ing] the readymade body of state law as
the federal rule of decision until Congress strikes a different
accommodation.” United States v. Kimbell Foods,
Inc. , 440 U. S.
715 , 740 (1979); see Bank of America Nat. Trust & Sav.
Assn. v. Parnell , 352 U. S. 29 , 32–34
(1956). And where, as here, borrowing the law of a particular State
would be inappropriate, the Court remains mindful that it does not
have creative power akin to that vested in Congress. See Missouri v. Illinois , 200 U. S. 496 , 519
(1906) (“fact that this court must decide does not mean, of course,
that it takes the place of a legislature”); cf. United
States v. Standard Oil Co. of Cal. , 332 U. S. 301 , 308, 314
(1947) (holding that federal law determines whether Government
could secure indemnity from a company whose truck injured a United
States soldier, but declining to impose such an indemnity absent
action by Congress, “the primary and most often the exclusive
arbiter of federal fiscal affairs”).

															   In the cases on which the plaintiffs heavily
rely, States were permitted to sue to challenge activity harmful to
their citizens’ health and welfare. We have not yet decided whether
private citizens (here, the land trusts) or political subdivisions
(New York City) of a State may invoke the federal common law of
nuisance to abate out-of-state pollution. Nor have we ever held
that a State may sue to abate any and all manner of pollution
originating outside its borders.

															   The defendants argue that considerations of
scale and complexity distinguish global warming from the more
bounded pollution giving rise to past federal nuisance suits.
Greenhouse gases once emitted “become well mixed in the
atmosphere,” 74 Fed. Reg. 66514; emissions in New Jersey may
contribute no more to flooding in New York than emissions in China.
Cf. Brief for Petitioners 18–19. The plaintiffs, on the other hand,
contend that an equitable remedy against the largest emitters of
carbon dioxide in the United States is in order and not beyond
judicial competence. See Brief for Respondents Open Space
In-stitute et al. 32–35. And we have recognized that public
nuisance law, like common law generally, adapts to changing
scientific and factual circumstances. Missouri , 200 U. S.,
at 522 (adjudicating claim though it did not concern “nuisance of
the simple kind that was known to the older common law”); see also D’Oench, Duhme & Co. v. FDIC , 315 U. S. 447 , 472
(1942) (Jackson, J., concurring) (“federal courts are free to apply
the traditional common-law technique of decision” when fashioning
federal common law).

															   We need not address the parties’ dispute in
this regard. For it is an academic question whether, in the absence
of the Clean Air Act and the EPA actions the Act authorizes, the
plaintiffs could state a federal common law claim for curtailment
of greenhouse gas emissions because of their contribution to global
warming. Any such claim would be displaced by the federal
legislation authorizing EPA to regulate carbon-dioxide
emissions.

															B

															   “[W]hen Congress addresses a
question previously governed by a decision rested on federal common
law,” the Court has explained, “the need for such an unusual
exercise of law-making by federal courts disappears.” Milwaukee
II , 451 U. S., at 314 (holding that amendments to the Clean
Water Act displaced the nuisance claim recognized in Milwaukee
I ). Legislative displacement of federal common law does not
require the “same sort of evidence of a clear and manifest
[congressional] purpose” demanded for preemption of state law. Id. , at 317. “ ‘[D]ue regard for the presuppositions
of our embracing federal system … as a promoter of
democracy,’ ” id. , at 316 (quoting San Diego
Building Trades Council v. Garmon , 359 U. S. 236 , 243
(1959)), does not enter the calculus, for it is primarily the
office of Congress, not the federal courts, to prescribe national
policy in areas of special federal interest. TVA v. Hill , 437
U. S. 153 , 194 (1978). The test for whether congressional
legislation excludes the declaration of federal common law is
simply whether the statute “speak[s] directly to [the] question” at
issue. Mobil Oil Corp. v. Higginbotham , 436 U. S. 618 , 625
(1978); see Milwaukee II , 451 U. S., at 315; County of
Oneida v. Oneida Indian Nation of N. Y. , 470 U. S. 226 , 236–237
(1985).

															   We hold that the Clean Air Act
and the EPA actions it authorizes displace any federal common law
right to seek abatement of carbon-dioxide emissions from
fossil-fuel fired power plants. Massachusetts made plain
that emissions of carbon dioxide qualify as air pollution subject
to regulation under the Act. 549 U. S., at 528–529. And we think it
equally plain that the Act “speaks directly” to emissions of carbon
dioxide from the defendants’ plants.

															   Section 111 of the Act directs the EPA
Administrator to list “categories of stationary sources” that “in
[her] judgment … caus[e], or contribut[e] significantly to, air
pol-lution which may reasonably be anticipated to endanger public
health or welfare.” §7411(b)(1)(A). Once EPA lists a category, the
agency must establish standards of performance for emission of
pollutants from new or modified sources within that category.
§7411(b)(1)(B); see also §7411(a)(2). And, most relevant here,
§7411(d) then requires regulation of existing sources within the
same category.[ Footnote 7 ] For
existing sources, EPA issues emissions guidelines, see 40 C. F. R.
§60.22, .23 (2009); in compliance with those guidelines and subject
to federal oversight, the States then issue performance standards
for stationary sources within their jurisdiction, §7411(d)(1).

															   The Act provides multiple avenues for
enforcement. See County of Oneida , 470 U. S., at 237–239
(reach of remedial provisions is important to determination whether
statute displaces federal common law). EPA may delegate
im-plementation and enforcement authority to the States,
§7411(c)(1), (d)(1), but the agency retains the power to in-spect
and monitor regulated sources, to impose administrative penalties
for noncompliance, and to commence civil actions against polluters
in federal court. §§7411(c)(2), (d)(2), 7413, 7414. In specified
circumstances, the Act im-poses criminal penalties on any person
who knowingly violates emissions standards issued under §7411. See
§7413(c). And the Act provides for private enforcement. If States
(or EPA) fail to enforce emissions limits against regulated
sources, the Act permits “any person” to bring a civil enforcement
action in federal court. §7604(a).

															   If EPA does not set emissions limits
for a particular pol-lutant or source of pollution, States and
private parties may petition for a rulemaking on the matter, and
EPA’s response will be reviewable in federal court. See
§7607(b)(1); Massachusetts , 549 U. S., at 516–517, 529. As
earlier noted, see supra , at 3, EPA is currently engaged
in a §7411 rulemaking to set standards for greenhouse gas emissions
from fossil-fuel fired power plants. To settle litigation brought
under §7607(b) by a group that included the majority of the
plaintiffs in this very case, the agency agreed to complete that
rulemaking by May 2012. 75 Fed. Reg. 82392. The Act itself thus
provides a means to seek limits on emissions of carbon dioxide from
domestic power plants—the same relief the plaintiffs seek by
invoking federal common law. We see no room for a parallel
track.

															C

															   The plaintiffs argue, as the
Second Circuit held, that federal common law is not displaced until
EPA actually exercises its regulatory authority, i.e. ,
until it sets standards governing emissions from the defendants’
plants. We disagree.

															   The sewage discharges at issue in Milwaukee II , we do not overlook, were subject to effluent
limits set by EPA; under the displacing statute, “[e]very point
source discharge” of water pollution was “prohibited unless covered
by a permit.” 451 U. S., at 318–320 (emphasis deleted). As Milwaukee II made clear, however, the relevant question
for purposes of displacement is “whether the field has been
occupied, not whether it has been occupied in a particular manner.” Id. , at 324. Of necessity, Congress se-lects different
regulatory regimes to address different problems. Congress could
hardly preemptively prohibit every discharge of carbon dioxide
unless covered by a permit. After all, we each emit carbon dioxide
merely by breathing.

															   The Clean Air Act is no less an exercise of
the legislature’s “considered judgment” concerning the regulation
of air pollution because it permits emissions until EPA
acts. See Middlesex County Sewerage Authority v. National Sea Clammers Assn. , 453 U. S. 1 , 22, n. 32
(1981) (finding displacement although Congress “allowed some
continued dumping of sludge” prior to a certain date). The critical
point is that Congress delegated to EPA the decision whether and
how to regulate carbon-dioxide emissions from power plants; the
delegation is what displaces federal common law. Indeed, were EPA
to decline to regulate carbon-dioxide emissions altogether at the
conclusion of its ongoing §7411 rulemaking, the federal courts
would have no warrant to employ the federal common law of nuisance
to upset the agency’s expert determination.

															   EPA’s judgment, we hasten to add, would not
escape judicial review. Federal courts, we earlier observed, see supra , at 11, can review agency action (or a final rule
declining to take action) to ensure compliance with the statute
Congress enacted. As we have noted, see supra , at 10, the
Clean Air Act directs EPA to establish emis- sions standards for
categories of stationary sources that, “in [the Administrator’s]
judgment,” “caus[e], or contri-but[e] significantly to, air
pollution which may reasonably be anticipated to endanger public
health or welfare.” §7411(b)(1)(A). “[T]he use of the word
‘judgment,’ ” we explained in Massachusetts , “is not
a roving license to ignore the statutory text.” 549 U. S., at 533.
“It is but a direction to exercise discretion within defined
statutory limits.” Ibid. EPA may not decline to regulate
carbon-dioxide emissions from power plants if refusal to act would
be “arbitrary, capricious, an abuse of discretion, or otherwise not
in accordance with law.” §7607(d)(9)(A). If the plaintiffs in this
case are dissatisfied with the outcome of EPA’s forthcoming
rulemaking, their recourse under federal law is to seek Court of
Appeals review, and, ultimately, to petition for certiorari in this
Court.

															   Indeed, this prescribed order of
decisionmaking—the first decider under the Act is the expert
administrative agency, the second, federal judges—is yet another
reason to resist setting emissions standards by judicial decree
under federal tort law. The appropriate amount of regulation in any
particular greenhouse gas-producing sector cannot be prescribed in
a vacuum: as with other questions of national or international
policy, informed assessment of competing interests is required.
Along with the environmental benefit potentially achievable, our
Nation’s energy needs and the possibility of economic disruption
must weigh in the balance.

															   The Clean Air Act entrusts such complex
balancing to EPA in the first instance, in combination with state
regulators. Each “standard of performance” EPA sets must “tak[e]
into account the cost of achieving [emissions] reduction and any
nonair quality health and environmental impact and energy
requirements.” §7411(a)(1), (b)(1)(B), (d)(1); see also 40 C.
F. R. §60.24(f) (EPA may permit state plans to deviate from
generally applicable emissions standards upon demonstration that
costs are “[u]n-reasonable”). EPA may “distinguish among classes,
types, and sizes” of stationary sources in apportioning
responsibility for emissions reductions. §7411(b)(2), (d); see also
40 C. F. R. §60.22(b)(5). And the agency may waive compliance with
emission limits to permit a facility to test drive an “innovative
technological system” that has “not [yet] been adequately
demonstrated.” §7411(j)(1)(A). The Act envisions extensive
cooperation between federal and state authorities, see §7401(a),
(b), generally permitting each State to take the first cut at
determining how best to achieve EPA emissions standards within its
domain, see §7411(c)(1), (d)(1)–(2).

															   It is altogether fitting that Congress
designated an ex-pert agency, here, EPA, as best suited to serve as
pri- mary regulator of greenhouse gas emissions. The expert agency
is surely better equipped to do the job than individual district
judges issuing ad hoc, case-by-case injunctions. Federal
judges lack the scientific, economic, and technological resources
an agency can utilize in coping with issues of this order. See
generally Chevron U. S. A. Inc. v. Natural
Resources Defense Council, Inc. , 467 U. S. 837 , 865–866
(1984). Judges may not commission scientific studies or convene
groups of experts for advice, or issue rules under
notice-and-comment procedures inviting input by any interested
person, or seek the counsel of regulators in the States where the
defendants are located. Rather, judges are confined by a record
comprising the evidence the parties present. Moreover, federal
district judges, sitting as sole adjudicators, lack authority to
render precedential decisions binding other judges, even members of
the same court.

															   Notwithstanding these disabilities, the
plaintiffs propose that individual federal judges determine, in the
first instance, what amount of carbon-dioxide emissions is
“unreasonable,” App. 103, 145, and then decide what level of
reduction is “practical, feasible and economically viable,” App.
58, 119. These determinations would be made for the defendants
named in the two lawsuits launched by the plaintiffs. Similar suits
could be mounted, counsel for the States and New York City
estimated, against “thousands or hundreds or tens” of other
defendants fitting the description “large contributors” to
carbon-dioxide emissions. Tr. of Oral Arg. 57.

															   The judgments the plaintiffs would commit to
federal judges, in suits that could be filed in any federal
district, cannot be reconciled with the decisionmaking scheme
Congress enacted. The Second Circuit erred, we hold, in ruling that
federal judges may set limits on greenhouse gas emissions in face
of a law empowering EPA to set the same limits, subject to judicial
review only to ensure against action “arbitrary, capricious, … or
otherwise not in accordance with law.” §7607(d)(9).

															V

															   The plaintiffs also sought relief
under state law, in particular, the law of each State where the
defendants operate power plants. See App. 105, 147. The Second
Circuit did not reach the state law claims because it held that
federal common law governed. 582 F. 3d, at 392; see International Paper Co. v. Ouellette , 479 U. S. 481 , 488
(1987) (if a case “should be resolved by reference to federal
common law[,] … state common law [is] preempted”). In light of our
holding that the Clean Air Act displaces federal common law, the
availability vel non of a state lawsuit depends, inter
alia , on the preemptive effect of the federal Act. Id. , at 489, 491, 497 (holding that the Clean Water Act
does not preclude aggrieved individuals from bringing a “nuisance
claim pursuant to the law of the source State”). None of
the parties have briefed preemption or otherwise addressed the
availability of a claim under state nuisance law. We therefore
leave the matter open for consideration on remand.

															*  *  *

															   For the reasons stated, we
reverse the judgment of the Second Circuit and remand the case for
further proceedings consistent with this opinion.

															It is so ordered.

															   Justice Sotomayor took no part in
the consideration or decision of this case. Footnote 1 In addition to carbon dioxide, the primary
greenhouse gases emitted by human activities include methane,
nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur
hexafluoride. 74 Fed. Reg. 66499. Footnote 2 For views opposing EPA’s, see, e.g. ,
Dawidoff, The Civil Heretic, N. Y. Times Magazine 32 (March
29, 2009). The Court, we caution, endorses no particular view of
the complicated issues related to carbon-dioxide emissions and
climate change. Footnote 3 California, Connecticut, Iowa, New Jersey,
New York, Rhode Island, Vermont, and Wisconsin, although New Jersey
and Wisconsin are no longer participating. Brief for Respondents
Connecticut et al. 3, n. 1. Footnote 4 Open Space Institute, Inc., Open Space
Conservancy, Inc., and Audubon Society of New Hampshire. Footnote 5 American Electric Power Company, Inc. (and a
wholly owned subsidiary), Southern Company, Xcel Energy Inc., and
Cinergy Corporation. Footnote 6 In addition to renewing the political
question argument made below, the petitioners now assert an
additional threshold obstacle: They seek dismissal because of a
“prudential” bar to the adjudication of generalized grievances,
purportedly distinct from Article III’s bar. See Brief for
Tennessee Valley Authority 14–24; Brief for Petitioners 30–31. Footnote 7 There is an exception: EPA may not employ
§7411(d) if existing stationary sources of the pollutant in
question are regulated under the national ambient air quality
standard program, §§7408–7410, or the “hazardous air pollutants”
program, §7412. See §7411(d)(1). 564 U. S. ____ (2011) 564 U. S. ____ (2011) 564 U. S. ____ (2011) SUPREME COURT OF THE UNITED STATES NO. 10-174 AMERICAN ELECTRIC POWER COMPANY, INC., et al.,
PETITIONERS v. CONNECTICUT et al.

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

															[June 20, 2011]

															   Justice Alito, with whom Justice
Thomas joins, concurring in part and concurring in the
judgment.

															   I concur in the judgment, and I
agree with the Court’s displacement analysis on the assumption
(which I make for the sake of argument because no party contends
otherwise) that the interpretation of the Clean Air Act, 42 U.
S. C. §7401 et seq ., adopted by the majority in Massachusetts v. EPA , 549 U. S. 497 (2007), is
correct.


Los Angeles County Flood Control Dist. v. NRDC

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, Washington,
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

															_________________

															No. 11–460

															_________________

															LOS ANGELES COUNTY FLOOD CONTROL DISTRICT
PETITIONER v. NATURAL RESOURCES DEFENSE COUNCIL, INC.,
et al.

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

															[January 8, 2013]

															Justice Ginsburg delivered the opinion of the
Court.

															The Court granted review in this case limited to
a single question: Under the Clean Water Act (CWA), 86 Stat. 816,
as amended, 33 U. S. C. §1251 et seq. , does
the flow of water out of a concrete channel within a river rank as
a “discharge of a pollutant”? In this Court, the parties and the
United States as amicus curiae agree that the answer to this
question is “no.” They base this accord on South Fla. Water
Management Dist. v. Miccosukee Tribe , 541 U.S.
95 , 109–112 (2004), in which we accepted that pumping polluted
water from one part of a water body into another part of the same
body is not a discharge of pol- lutants under the CWA. Adhering to
the view we took in Miccosukee , we hold that the parties
correctly answered the sole question presented in the negative. The
decision in this suit rendered by the Court of Appeals for the
Ninth Circuit is inconsistent with our determination. We therefore
reverse that court’s judgment.

															Petitioner Los Angeles County Flood Control
District (District) operates a “municipal separate storm sewer
system” (MS4)—a drainage system that collects, transports, and
discharges storm water. See 40 CFR §122.26(b)(8) (2012). See also
§122.26(b)(13) (“ Storm water means storm water runoff, snow
melt runoff, and surface runoff and drainage.”). Because storm
water is often heavily polluted, see 64 Fed. Reg. 68724–68727
(1999), the CWA and its implementing regulations require the
operator of an MS4 serving a population of at least 100,000 to
obtain a National Pollutant Discharge Elimination System (NPDES)
permit before discharging storm water into navigable waters. See 33
U. S. C. §§1311(a), 1342(p)(2)(C), and (D); 40 CFR
§§122.26(a)(3), (b)(4), (b)(7). The District first obtained a NPDES
permit for its MS4 in 1990; thereafter, the permit was several
times renewed. Natural Resources Defense Council, Inc. v. County of Los Angeles , 673 F.3d 880, 886 (CA9 2011).

															Respondents Natural Resources Defense Council,
Inc. (NRDC) and Santa Monica Baykeeper (Baykeeper) filed a citizen
suit against the District and several other defendants under §505
of the CWA, 33 U. S. C. §1365. They alleged, among other
things, that water-quality measurements from monitoring stations
located within the Los Angeles and San Gabriel Rivers demonstrated
that the District was violating the terms of its permit.

															The District Court granted summary judgment to
the District on these claims. It was undisputed, the District Court
acknowledged, that “data from the Los Angeles River and San Gabriel
River [monitoring] stations indicate[d] that water quality
standards ha[d] repeatedly been exceeded for a number of
pollutants, including aluminum, copper, cyanide, fecal coliform
bacteria, and zinc.” App. to Pet. for Cert. 108. But numerous
entities other than the District, the court added, discharge into
the rivers upstream of the monitoring stations. See id. , at
115–116. See also 673 F. 3d, at 889 (observing that the
pollutants of “thousands of permitted dischargers” reach the
rivers). The record was insufficient, the District Court concluded,
to warrant a finding that the District’s MS4 had discharged storm
water containing the standards-exceeding pollutants detected at the
downstream monitoring stations.

															The Ninth Circuit reversed in relevant part. The
monitoring stations for the Los Angeles and San Gabriel Rivers, the
Court of Appeals said, are located in “concrete channels”
constructed for flood-control purposes. Id. , at 900. See
also id. , at 889 (describing the monitoring stations’
location). Based on this impression, the Court of Appeals held that
a discharge of pollutants occurred under the CWA when the polluted
water detected at the monitoring stations “flowed out of the
concrete channels” and entered downstream portions of the waterways
lacking concrete linings. Id. , at 900. Because the District
exer- cises control over the concrete-lined portions of the rivers,
the Court of Appeals held, the District is liable for the
discharges that, in the appellate court’s view, occur when water
exits those concrete channels. See id. , at 899–901.

															We granted certiorari on the following question:
Under the CWA, does a “discharge of pollutants” occur when polluted
water “flows from one portion of a river that is navigable water of
the United States, through a concrete channel or other engineered
improvement in the river,” and then “into a lower portion of the
same river”? Pet. for Cert. i. See 567 U. S. ___ (2012). As
noted above, see supra , at 1, the parties, as well as the
United States as amicus curiae , agree that the answer to
this question is “no.”

															That agreement is hardly surprising, for we held
in Miccosukee that the transfer of polluted water between
“two parts of the same water body” does not constitute a discharge
of pollutants under the CWA. 541 U. S., at 109–112. We derived
that determination from the CWA’s text, which defines the term
“discharge of a pollutant” to mean “any addition of any
pollutant to navigable waters from any point source.” 33
U. S. C. §1362(12) (emphasis added). Under a common
understanding of the meaning of the word “add,” no pollutants are
“added” to a water body when water is merely transferred between
different portions of that water body. See Webster’s Third New
International Dictionary 24 (2002) (“add” means “to join, annex, or
unite (as one thing to another) so as to bring about an increase
(as in number, size, or importance) or so as to form one
aggregate”). “As the Second Circuit [aptly] put it . . .
, ‘[i]f one takes a ladle of soup from a pot, lifts it above the
pot, and pours it back into the pot, one has not “added” soup or
anything else to the pot.’ ” Miccosukee , 541
U. S., at 109–110 (quoting Catskill Mountains Chapter of
Trout Unlimited, Inc. v. New York , 273 F.3d 481 , 492 (CA2 2001)).

															In Miccosukee , polluted water was removed
from a ca- nal, transported through a pump station, and then de-
posited into a nearby reservoir. 541 U. S., at 100. We held
that this water transfer would count as a discharge of pollutants
under the CWA only if the canal and the reservoir were
“meaningfully distinct water bodies.” Id. , at 112. It
follows, a fortiori , from Miccosukee that no
discharge of pollutants occurs when water, rather than being
removed and then returned to a water body, simply flows from one
portion of the water body to another. We hold, therefore, that the
flow of water from an improved portion of a navigable waterway into
an unimproved portion of the very same waterway does not qualify as
a discharge of pollutants under the CWA. Because the decision below
cannot be squared with that holding, the Court of Appeals’ judgment
must be reversed.[ 1 ]

															The NRDC and Baykeeper urge that the Court of
Appeals reached the right result, albeit for the wrong reason. The
monitoring system proposed by the District and written into its
permit showed numerous instances in which water-quality standards
were exceeded. Under the permit’s terms, the NRDC and Baykeeper
maintain, the ex- ceedances detected at the instream monitoring
stations are by themselves sufficient to establish the District’s
liability under the CWA for its upstream discharges. See Brief for
Respondents 33–62.[ 2 ] This
argument failed below. See 673 F. 3d, at 898, 901; App. to
Pet. for Cert. 100–102. It is not embraced within, or even touched
by, the narrow question on which we granted certiorari. We
therefore do not address, and indicate no opinion on, the issue the
NRDC and Baykeeper seek to substitute for the question we took up
for review.

															*  *  *

															For the reasons stated, the judgment of the
Court of Appeals for the Ninth Circuit is reversed, and the case is
remanded.

															It is so ordered.

															Justice Alito concurs in the judgment. Notes 1 The NRDC, Baykeeper, and
the United States contend—contrary to the District—that the Court
of Appeals understood that no discharge of pollutants occurs when
water flows from an improved into an unimproved portion of a
navigable waterway. They suggest that the Court of Appeals
misperceived the facts, erroneously believing that the monitoring
stations for the Los Angeles and San Gabriel Rivers “were sampling
water from a portion of the MS4 that was distinct from the rivers
themselves and from which discharges through an outfall to the
rivers subsequently occurred.” Brief for United States as Amicus
Curiae 18. See also Brief for Respondents 30–31 (“The court of
appeals’ statements suggest it believed the monitoring stations
sampled polluted stormwater from the District’s MS4 before, not
after, discharge to the Los Angeles and San Gabriel Rivers.”).
Whatever the source of the Court of Appeals’ error, all parties
agree that the court’s analysis was erroneous. 2 Shortly before oral
argument in this case, a renewed permit was approved for the
District’s MS4. Unlike the District’s prior permit, which required
only instream monitoring, the renewed permit requires end-of-pipe
monitoring at individual MS4 discharge points. See id. , at
20–21; Reply Brief 5, n. 2.