FRIENDS OF THE EARTH, INC., et al. v. LAIDLAW ENVIRONMENTAL SERVICES (TOC), INC.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
167 OCTOBER TERM, 1999
Syllabus
FRIENDS OF THE EARTH, INC., et al. v. LAIDLAW
ENVIRONMENTAL SERVICES (TOC), INC.
certiorari to the united states court of appeals for
the fourth circuit
No. 98–822. Argued October 12, 1999—Decided January 12, 2000
Defendant-respondent Laidlaw Environmental Services (TOC), Inc.,
bought a facility in Roebuck, South Carolina, that included a wastewater
treatment plant. Shortly thereafter, the South Carolina Department of
Health and Environmental Control (DHEC), acting under the Clean
Water Act (Act), 33 U. S. C. § 1342(a)(1), granted Laidlaw a National Pol-
lutant Discharge Elimination System (NPDES) permit. The permit
authorized Laidlaw to discharge treated water into the North Tyger
River, but limited, among other things, the discharge of pollutants into
the waterway. Laidlaw began to discharge various pollutants into the
waterway; these discharges, particularly of mercury, an extremely toxic
pollutant, repeatedly exceeded the limits set by the permit.
On April 10, 1992, plaintiff-petitioners Friends of the Earth and Citi-
zens Local Environmental Action Network, Inc. (referred to collectively
here, along with later joined plaintiff-petitioner Sierra Club, as “FOE”),
notified Laidlaw of their intention to file a citizen suit against it under
the Act, 33 U. S. C. § 1365(a), after the expiration of the requisite 60-day
notice period. DHEC acceded to Laidlaw’s request to file a lawsuit
against the company. On the last day before FOE’s 60-day notice pe-
riod expired, DHEC and Laidlaw reached a settlement requiring Laid-
law to pay $100,000 in civil penalties and to make “every effort” to com-
ply with its permit obligations.
On June 12, 1992, FOE filed this citizen suit against Laidlaw, alleging
noncompliance with the NPDES permit and seeking declaratory and
injunctive relief and an award of civil penalties. Laidlaw moved for
summary judgment on the ground that FOE lacked Article III standing
to bring the lawsuit. After examining affidavits and deposition testi-
mony from members of the plaintiff organizations, the District Court
denied the motion, finding that the plaintiffs had standing. The Dis-
trict Court also denied Laidlaw’s motion to dismiss on the ground that
the citizen suit was barred under § 1365(b)(1)(B) by DHEC’s prior action
against the company. After FOE initiated this suit, but before the Dis-
trict Court rendered judgment on January 22, 1997, Laidlaw violated
the mercury discharge limitation in its permit 13 times and committed
13 monitoring and 10 reporting violations. In issuing its judgment, the

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
168 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Syllabus
District Court found that Laidlaw had gained a total economic benefit
of $1,092,581 as a result of its extended period of noncompliance with
the permit’s mercury discharge limit; nevertheless, the court concluded
that a civil penalty of $405,800 was appropriate. In particular, the Dis-
trict Court found that the judgment’s “total deterrent effect” would be
adequate to forestall future violations, given that Laidlaw would have
to reimburse the plaintiffs for a significant amount of legal fees and had
itself incurred significant legal expenses. The court declined to order
injunctive relief because Laidlaw, after the lawsuit began, had achieved
substantial compliance with the terms of its permit.
FOE appealed as to the amount of the District Court’s civil penalty
judgment, but did not appeal the denial of declaratory or injunctive
relief. The Fourth Circuit vacated the District Court’s order and re-
manded with instructions to dismiss the action. Assuming, arguendo,
that FOE initially had standing, the appellate court held that the case
had become moot once Laidlaw complied with the terms of its permit
and the plaintiffs failed to appeal the denial of equitable relief. Citing
Steel Co. v. Citizens for Better Environment, 523 U. S. 83, the court
reasoned that the only remedy currently available to FOE, civil penal-
ties payable to the Government, would not redress any injury FOE had
suffered. The court added that FOE’s failure to obtain relief on the
merits precluded recovery of attorneys’ fees or costs because such an
award is available only to a “prevailing or substantially prevailing
party” under § 1365(d). According to Laidlaw, the entire Roebuck facil-
ity has since been permanently closed, dismantled, and put up for sale,
and all discharges from the facility have permanently ceased.
Held: The Fourth Circuit erred in concluding that a citizen suitor’s claim
for civil penalties must be dismissed as moot when the defendant, after
commencement of the litigation, has come into compliance with its
NPDES permit. Pp. 180–195.
(a) The Constitution’s case-or-controversy limitation on federal judi-
cial authority, Art. III, § 2, underpins both standing and mootness doc-
trine, but the two inquiries differ in crucial respects. Because the
Fourth Circuit was persuaded that the case had become moot, it simply
assumed that FOE had initial standing. See Arizonans for Official
English v. Arizona, 520 U. S. 43, 66–67. But because this Court con-
cludes that the Court of Appeals erred as to mootness, this Court has
an obligation to assure itself that FOE had Article III standing at the
outset of the litigation. P. 180.
(b) FOE had Article III standing to bring this action. This Court
has held that to satisfy Article III’s standing requirements, a plaintiff
must show “injury in fact,” causation, and redressability. Lujan v. De-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
169 Cite as: 528 U. S. 167 (2000)
Syllabus
fenders of Wildlife, 504 U. S. 555, 560–561. An association has standing
to bring suit on behalf of its members when its members would have
standing to sue in their own right, the interests at stake are germane
to the organization’s purpose, and neither the claim asserted nor the
relief requested requires individual members’ participation in the law-
suit. Hunt v. Washington State Apple Advertising Comm’n, 432 U. S.
333, 343. The relevant showing for Article III standing is not injury to
the environment but injury to the plaintiff. To insist on the former
rather than the latter is to raise the standing hurdle higher than the
necessary showing for success on the merits in a citizen’s NPDES per-
mit enforcement suit. Here, injury in fact was adequately documented
by the affidavits and testimony of FOE members asserting that Laid-
law’s pollutant discharges, and the affiants’ reasonable concerns about
the effects of those discharges, directly affected those affiants’ recre-
ational, aesthetic, and economic interests. See, e. g., Sierra Club v.
Morton, 405 U. S. 727, 735. These submissions present dispositively
more than the mere “general averments” and “conclusory allegations”
found inadequate in Lujan v. National Wildlife Federation, 497 U. S.
871, 888, or the “ ‘some day’ intentions” to visit endangered species half-
way around the world held insufficient in Defenders of Wildlife. 504
U. S., at 564. Pp. 180–185.
(c) Laidlaw argues that FOE lacked standing to seek civil penalties
payable to the Government, because such penalties offer no redress to
citizen plaintiffs. For a plaintiff who is injured or threatened with in-
jury due to illegal conduct ongoing at the time of suit, a sanction that
effectively abates that conduct and prevents its recurrence provides a
form of redress. Civil penalties can fit that description. Insofar as
they encourage defendants to discontinue current violations and deter
future ones, they afford redress to citizen plaintiffs injured or threat-
ened with injury as a result of ongoing unlawful conduct. The Court
need not explore the outer limits of the principle that civil penalties
provide sufficient deterrence to support redressability, because the civil
penalties sought here carried a deterrent effect that made it likely, as
opposed to merely speculative, that the penalties would redress FOE’s
injuries—as the District Court reasonably found when it assessed a pen-
alty of $405,800. Steel Co. is not to the contrary. That case held that
private plaintiffs may not sue to assess penalties for wholly past viola-
tions, 523 U. S., at 106–107, but did not address standing to seek penal-
ties for violations ongoing at the time of the complaint that could con-
tinue into the future if undeterred, see id., at 108. Pp. 185–188.
(d) FOE’s civil penalties claim did not automatically become moot
once the company came into substantial compliance with its permit. A
defendant’s voluntary cessation of a challenged practice ordinarily does

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
170 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Syllabus
not deprive a federal court of its power to determine the legality of the
practice. City of Mesquite v. Aladdin’s Castle, Inc., 455 U. S. 283, 289.
If it did, courts would be compelled to leave the defendant free to return
to its old ways. Thus, the standard for determining whether a case has
been mooted by the defendant’s voluntary conduct is stringent: A case
might become moot if subsequent events make it absolutely clear that
the allegedly wrongful behavior could not reasonably be expected to
recur. United States v. Concentrated Phosphate Export Assn., Inc.,
393 U. S. 199, 203. The heavy burden of persuading the court that the
challenged conduct cannot reasonably be expected to recur lies with
the party asserting mootness. Ibid. The Court of Appeals incorrectly
conflated this Court’s case law on initial standing, see, e. g., Steel Co.,
with its case law on mootness, see, e. g., City of Mesquite. Such confu-
sion is understandable, given this Court’s repeated description of moot-
ness as “the doctrine of standing set in a time frame: The requisite
personal interest that must exist at the commencement of the litigation
(standing) must continue throughout its existence (mootness).” E. g.,
Arizonans, 520 U. S., at 68, n. 22. Careful reflection, however, reveals
that this description of mootness is not comprehensive. For example,
a defendant claiming that its voluntary compliance moots a case bears a
formidable burden. By contrast, it is the plaintiff ’s burden, in a lawsuit
brought to force compliance, to establish standing by demonstrating
that, if unchecked by the litigation, the defendant’s allegedly wrongful
behavior will likely occur or continue and that the threatened injury is
certainly impending. Whitmore v. Arkansas, 495 U. S. 149, 158. The
plain lesson is that there are circumstances in which the prospect that
a defendant will engage in (or resume) harmful conduct may be too
speculative to support standing, but not too speculative to overcome
mootness. Further, if mootness were simply “standing set in a time
frame,” the exception to mootness for acts that are “capable of repeti-
tion, yet evading review” could not exist. See, e. g., Olmstead v. L. C.,
527 U. S. 581, 594, n. 6. Standing admits of no similar exception; if a
plaintiff lacks standing at the time the action commences, the fact that
the dispute is capable of repetition yet evading review will not entitle
the complainant to a federal judicial forum. See, e. g., Steel Co., 523
U. S., at 109. Standing doctrine ensures, among other things, that the
resources of the federal courts are devoted to disputes in which the
parties have a concrete stake. Yet by the time mootness is an issue,
abandonment of the case may prove more wasteful than frugal. Courts
have no license to retain jurisdiction over cases in which one or both of
the parties plainly lacks a continuing interest, see, e. g., Arizonans, 520
U. S., at 67, but the foregoing examples highlight an important differ-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
171 Cite as: 528 U. S. 167 (2000)
Syllabus
fence between the two doctrines, see generally Honig v. Doe, 484 U. S.
305, 329–332 (Rehnquist, C. J., concurring).
Laidlaw’s argument that FOE doomed its own civil penalty claim to
mootness by failing to appeal the denial of injunctive relief misconceives
the statutory scheme. Under § 1365(a), the district court has discretion
to determine which form of relief is best suited to abate current viola-
tions and deter future ones. See Weinberger v. Romero-Barcelo, 456
U. S. 305, 313. Denial of injunctive relief does not necessarily mean
that the district court has concluded there is no prospect of future viola-
tions to deter. Indeed, it meant no such thing in this case; the District
Court denied injunctive relief, but expressly based its award of civil
penalties on the need for deterrence. A district court properly may
conclude that an injunction would be too intrusive, because it could en-
tail continuing and burdensome superintendence of the permit holder’s
activities by a federal court. See City of Mesquite, 455 U. S., at 289.
Both Laidlaw’s permit compliance and the facility closure might moot
this case, but only if one or the other event made it absolutely clear that
violations could not reasonably be expected to recur. Concentrated
Phosphate Export Assn., 393 U. S., at 203. These are disputed factual
matters that have not been aired in the lower courts; they remain open
for consideration on remand. Pp. 189–194.
(e) This Court does not resolve FOE’s argument that it is entitled to
attorneys’ fees on the theory that a plaintiff can be a “prevailing party”
under § 1365(d) if it was the “catalyst” that triggered a favorable out-
come. Although the Circuits have divided as to the continuing validity
of the catalyst theory following Farrar v. Hobby, 506 U. S. 103, it would
be premature for this Court to address the question here. The District
Court stayed the time for a petition for attorneys’ fees until the time
for appeal had expired or until any appeal was resolved. Thus, when
the Fourth Circuit addressed the availability of counsel fees, no order
was before it either denying or awarding fees. It is for the District
Court, not this Court, to address in the first instance any request for
reimbursement of costs, including fees. Pp. 194–195.
149 F. 3d 303, reversed and remanded.
Ginsburg, J., delivered the opinion of the Court, in which Rehnquist,
C. J., and Stevens, O’Connor, Kennedy, Souter, and Breyer, JJ.,
joined. Stevens, J., post, p. 195, and Kennedy, J., post, p. 197, filed con-
curring opinions. Scalia, J., filed a dissenting opinion, in which Thomas,
J., joined, post, p. 198.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
172 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Counsel
Bruce J. Terris argued the cause for petitioners. With
him on the briefs were Carolyn Smith Pravlik and James
S. Chandler, Jr.
Jeffrey P. Minear argued the cause for the United States
as amicus curiae in support of petitioners. With him on the
brief were Solicitor General Waxman, Assistant Attorney
General Schiffer, Deputy Solicitor General Wallace, and
David C. Shilton.
Donald A. Cockrill argued the cause for respondent.
With him on the briefs were Stuart H. Newberger, Clifton
S. Elgarten, Scott E. Gant, Henry H. Taylor, and Barbara
J. Hamilton.*
*Briefs of amici curiae urging reversal were filed for the State of Cali-
fornia et al. by Jeremiah W. (Jay) Nixon, Attorney General of Missouri,
James R. Layton, State Solicitor, Joseph P. Bindbeutel and William
J. Bryan, Assistant Attorneys General, Bill Lockyer, Attorney General
of California, Roderick E. Walston, Chief Assistant Attorney General,
Richard M. Frank, Assistant Attorney General, and Linus Masouredis,
Deputy Attorney General, and by the Attorneys General for their respec-
tive States as follows: Mark Pryor of Arkansas, M. Jane Brady of Dela-
ware, James E. Ryan of Illinois, Jennifer M. Granholm of Michigan, Mike
Moore of Mississippi, Patricia A. Madrid of New Mexico, Eliot Spitzer of
New York, Michael F. Easley of North Carolina, Sheldon Whitehouse of
Rhode Island, Paul G. Summers of Tennessee, and Christine O. Gregoire
of Washington; for Americans for the Environment by John D. Echeverria;
and for Public Citizen et al. by Colette G. Matzzie, Brian Wolfman, and
Steven R. Shapiro.
Briefs of amici curiae urging affirmance were filed for the State
of South Carolina by Charles M. Condon, Attorney General, and Kenneth
P. Woodington, Senior Assistant Attorney General; for the Alliance of
Automobile Manufacturers et al. by Scott M. DuBoff, Kenneth S. Kauf-
man, Robin S. Conrad, David R. Case, J. Walker Henry, Jan Amundson,
and Deborah Ann Hottel; for the California Association of Sanitation
Agencies by Louis F. Claiborne and John Briscoe; for Hercules Inc., by
Joel Schneider and Peter L. Frattarelli; and for the Washington Legal
Foundation et al. by Daniel J. Popeo and Paul D. Kamenar.
Briefs of amici curiae were filed for 40 California Cities et al. by
Rick W. Jarvis; for the Natural Resources Defense Council, Inc., et al.
by Michael Axline and David A. Nicholas; and for the Pacific Legal Foun-
dation et al. by Robin L. Rivett and M. Reed Hopper.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
173 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
Justice Ginsburg delivered the opinion of the Court.
This case presents an important question concerning the
operation of the citizen-suit provisions of the Clean Water
Act. Congress authorized the federal district courts to
entertain Clean Water Act suits initiated by “a person or
persons having an interest which is or may be adversely
affected.” 33 U. S. C. §§ 1365(a), (g). To impel future com-
pliance with the Act, a district court may prescribe injunc-
tive relief in such a suit; additionally or alternatively, the
court may impose civil penalties payable to the United States
Treasury. § 1365(a). In the Clean Water Act citizen suit
now before us, the District Court determined that injunctive
relief was inappropriate because the defendant, after the in-
stitution of the litigation, achieved substantial compliance
with the terms of its discharge permit. 956 F. Supp. 588,
611 (SC 1997). The court did, however, assess a civil pen-
alty of $405,800. Id., at 610. The “total deterrent effect”
of the penalty would be adequate to forestall future vio-
lations, the court reasoned, taking into account that the
defendant “will be required to reimburse plaintiffs for a
significant amount of legal fees and has, itself, incurred
significant legal expenses.” Id., at 610–611.
The Court of Appeals vacated the District Court’s order.
149 F. 3d 303 (CA4 1998). The case became moot, the appel-
late court declared, once the defendant fully complied with
the terms of its permit and the plaintiff failed to appeal the
denial of equitable relief. “[C]ivil penalties payable to the
government,” the Court of Appeals stated, “would not re-
dress any injury Plaintiffs have suffered.” Id., at 307. Nor
were attorneys’ fees in order, the Court of Appeals noted,
because absent relief on the merits, plaintiffs could not qual-
ify as prevailing parties. Id., at 307, n. 5.
We reverse the judgment of the Court of Appeals. The
appellate court erred in concluding that a citizen suitor’s
claim for civil penalties must be dismissed as moot when the

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
174 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
defendant, albeit after commencement of the litigation, has
come into compliance. In directing dismissal of the suit on
grounds of mootness, the Court of Appeals incorrectly con-
flated our case law on initial standing to bring suit, see, e. g.,
Steel Co. v. Citizens for Better Environment, 523 U. S. 83
(1998), with our case law on postcommencement mootness,
see, e. g., City of Mesquite v. Aladdin’s Castle, Inc., 455 U. S.
283 (1982). A defendant’s voluntary cessation of allegedly
unlawful conduct ordinarily does not suffice to moot a case.
The Court of Appeals also misperceived the remedial poten-
tial of civil penalties. Such penalties may serve, as an al-
ternative to an injunction, to deter future violations and
thereby redress the injuries that prompted a citizen suitor
to commence litigation.
I
A
In 1972, Congress enacted the Clean Water Act (Act), also
known as the Federal Water Pollution Control Act, 86 Stat.
816, as amended, 33 U. S. C. § 1251 et seq. Section 402 of
the Act, 33 U. S. C. § 1342, provides for the issuance, by the
Administrator of the Environmental Protection Agency
(EPA) or by authorized States, of National Pollutant Dis-
charge Elimination System (NPDES) permits. NPDES
permits impose limitations on the discharge of pollutants,
and establish related monitoring and reporting require-
ments, in order to improve the cleanliness and safety of the
Nation’s waters. Noncompliance with a permit constitutes
a violation of the Act. § 1342(h).
Under § 505(a) of the Act, a suit to enforce any limitation
in an NPDES permit may be brought by any “citizen,” de-
fined as “a person or persons having an interest which is
or may be adversely affected.” 33 U. S. C. §§ 1365(a), (g).
Sixty days before initiating a citizen suit, however, the
would-be plaintiff must give notice of the alleged violation
to the EPA, the State in which the alleged violation oc-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
175 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
curred, and the alleged violator. § 1365(b)(1)(A). “[T]he
purpose of notice to the alleged violator is to give it an op-
portunity to bring itself into complete compliance with the
Act and thus . . . render unnecessary a citizen suit.” Gwalt-
ney of Smithfield, Ltd. v. Chesapeake Bay Foundation,
Inc., 484 U. S. 49, 60 (1987). Accordingly, we have held
that citizens lack statutory standing under § 505(a) to sue
for violations that have ceased by the time the complaint
is filed. Id., at 56–63. The Act also bars a citizen from
suing if the EPA or the State has already commenced,
and is “diligently prosecuting,” an enforcement action. 33
U. S. C. § 1365(b)(1)(B).
The Act authorizes district courts in citizen-suit proceed-
ings to enter injunctions and to assess civil penalties, which
are payable to the United States Treasury. § 1365(a). In
determining the amount of any civil penalty, the district
court must take into account “the seriousness of the violation
or violations, the economic benefit (if any) resulting from
the violation, any history of such violations, any good-faith
efforts to comply with the applicable requirements, the eco-
nomic impact of the penalty on the violator, and such other
matters as justice may require.” § 1319(d). In addition, the
court “may award costs of litigation (including reasonable
attorney and expert witness fees) to any prevailing or sub-
stantially prevailing party, whenever the court determines
such award is appropriate.” § 1365(d).
B
In 1986, defendant-respondent Laidlaw Environmental
Services (TOC), Inc., bought a hazardous waste incinerator
facility in Roebuck, South Carolina, that included a waste-
water treatment plant. (The company has since changed
its name to Safety-Kleen (Roebuck), Inc., but for simplicity
we will refer to it as “Laidlaw” throughout.) Shortly after
Laidlaw acquired the facility, the South Carolina Department

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
176 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
of Health and Environmental Control (DHEC), acting under
33 U. S. C. § 1342(a)(1), granted Laidlaw an NPDES permit
authorizing the company to discharge treated water into the
North Tyger River. The permit, which became effective on
January 1, 1987, placed limits on Laidlaw’s discharge of sev-
eral pollutants into the river, including—of particular rele-
vance to this case—mercury, an extremely toxic pollutant.
The permit also regulated the flow, temperature, toxicity,
and pH of the effluent from the facility, and imposed monitor-
ing and reporting obligations.
Once it received its permit, Laidlaw began to discharge
various pollutants into the waterway; repeatedly, Laidlaw’s
discharges exceeded the limits set by the permit. In partic-
ular, despite experimenting with several technological fixes,
Laidlaw consistently failed to meet the permit’s stringent 1.3
ppb (parts per billion) daily average limit on mercury dis-
charges. The District Court later found that Laidlaw had
violated the mercury limits on 489 occasions between 1987
and 1995. 956 F. Supp., at 613–621.
On April 10, 1992, plaintiff-petitioners Friends of the
Earth (FOE) and Citizens Local Environmental Action Net-
work, Inc. (CLEAN) (referred to collectively in this opinion,
together with later joined plaintiff-petitioner Sierra Club, as
“FOE”) took the preliminary step necessary to the institu-
tion of litigation. They sent a letter to Laidlaw notifying
the company of their intention to file a citizen suit against it
under § 505(a) of the Act after the expiration of the requisite
60-day notice period, i. e., on or after June 10, 1992. Laid-
law’s lawyer then contacted DHEC to ask whether DHEC
would consider filing a lawsuit against Laidlaw. The Dis-
trict Court later found that Laidlaw’s reason for request-
ing that DHEC file a lawsuit against it was to bar FOE’s
proposed citizen suit through the operation of 33 U. S. C.
§ 1365(b)(1)(B). 890 F. Supp. 470, 478 (SC 1995). DHEC
agreed to file a lawsuit against Laidlaw; the company’s law-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
177 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
yer then drafted the complaint for DHEC and paid the filing
fee. On June 9, 1992, the last day before FOE’s 60-day no-
tice period expired, DHEC and Laidlaw reached a settle-
ment requiring Laidlaw to pay $100,000 in civil penalties and
to make “ ‘every effort’ ” to comply with its permit obliga-
tions. Id., at 479–481.
On June 12, 1992, FOE filed this citizen suit against Laid-
law under § 505(a) of the Act, alleging noncompliance with
the NPDES permit and seeking declaratory and injunctive
relief and an award of civil penalties. Laidlaw moved for
summary judgment on the ground that FOE had failed to
present evidence demonstrating injury in fact, and therefore
lacked Article III standing to bring the lawsuit. Record,
Doc. No. 43. In opposition to this motion, FOE submitted
affidavits and deposition testimony from members of the
plaintiff organizations. Record, Doc. No. 71 (Exhs. 41–51).
The record before the District Court also included affidavits
from the organizations’ members submitted by FOE in sup-
port of an earlier motion for preliminary injunctive relief.
Record, Doc. No. 21 (Exhs. 5–10). After examining this evi-
dence, the District Court denied Laidlaw’s summary judg-
ment motion, finding—albeit “by the very slimmest of mar-
gins”—that FOE had standing to bring the suit. App. in
No. 97–1246 (CA4), pp. 207–208 (Tr. of Hearing 39–40 (June
30, 1993)).
Laidlaw also moved to dismiss the action on the ground
that the citizen suit was barred under 33 U. S. C.
§ 1365(b)(1)(B) by DHEC’s prior action against the company.
The United States, appearing as amicus curiae, joined FOE
in opposing the motion. After an extensive analysis of the
Laidlaw-DHEC settlement and the circumstances under
which it was reached, the District Court held that DHEC’s
action against Laidlaw had not been “diligently prosecuted”;
consequently, the court allowed FOE’s citizen suit to pro-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
178 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
ceed. 890 F. Supp., at 499.1 The record indicates that after
FOE initiated the suit, but before the District Court ren-
dered judgment, Laidlaw violated the mercury discharge
limitation in its permit 13 times. 956 F. Supp., at 621. The
District Court also found that Laidlaw had committed 13
monitoring and 10 reporting violations during this period.
Id., at 601. The last recorded mercury discharge violation
occurred in January 1995, long after the complaint was filed
but about two years before judgment was rendered. Id.,
at 621.
On January 22, 1997, the District Court issued its judg-
ment. 956 F. Supp. 588 (SC). It found that Laidlaw had
gained a total economic benefit of $1,092,581 as a result of its
extended period of noncompliance with the mercury dis-
charge limit in its permit. Id., at 603. The court concluded,
however, that a civil penalty of $405,800 was adequate in
light of the guiding factors listed in 33 U. S. C. § 1319(d). 956
F. Supp., at 610. In particular, the District Court stated
that the lesser penalty was appropriate taking into account
the judgment’s “total deterrent effect.” In reaching this
determination, the court “considered that Laidlaw will be
required to reimburse plaintiffs for a significant amount of
legal fees.” Id., at 610–611. The court declined to grant
FOE’s request for injunctive relief, stating that an injunction
was inappropriate because “Laidlaw has been in substantial
compliance with all parameters in its NPDES permit since
at least August 1992.” Id., at 611.
1 The District Court noted that “Laidlaw drafted the state-court com-
plaint and settlement agreement, filed the lawsuit against itself, and paid
the filing fee.” 890 F. Supp., at 489. Further, “the settlement agreement
between DHEC and Laidlaw was entered into with unusual haste, without
giving the Plaintiffs the opportunity to intervene.” Ibid. The court
found “most persuasive” the fact that “in imposing the civil penalty of
$100,000 against Laidlaw, DHEC failed to recover, or even to calculate,
the economic benefit that Laidlaw received by not complying with its per-
mit.” Id., at 491.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
179 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
FOE appealed the District Court’s civil penalty judg-
ment, arguing that the penalty was inadequate, but did not
appeal the denial of declaratory or injunctive relief. Laid-
law cross-appealed, arguing, among other things, that FOE
lacked standing to bring the suit and that DHEC’s action
qualified as a diligent prosecution precluding FOE’s litiga-
tion. The United States continued to participate as amicus
curiae in support of FOE.
On July 16, 1998, the Court of Appeals for the Fourth Cir-
cuit issued its judgment. 149 F. 3d 303. The Court of Ap-
peals assumed without deciding that FOE initially had
standing to bring the action, id., at 306, n. 3, but went on to
hold that the case had become moot. The appellate court
stated, first, that the elements of Article III standing—in-
jury, causation, and redressability—must persist at every
stage of review, or else the action becomes moot. Id., at
306. Citing our decision in Steel Co., the Court of Appeals
reasoned that the case had become moot because “the only
remedy currently available to [FOE]—civil penalties payable
to the government—would not redress any injury [FOE has]
suffered.” 149 F. 3d, at 306–307. The court therefore va-
cated the District Court’s order and remanded with instruc-
tions to dismiss the action. In a footnote, the Court of Ap-
peals added that FOE’s “failure to obtain relief on the merits
of [its] claims precludes any recovery of attorneys’ fees or
other litigation costs because such an award is available only
to a ‘prevailing or substantially prevailing party.’ ” Id., at
307, n. 5 (quoting 33 U. S. C. § 1365(d)).
According to Laidlaw, after the Court of Appeals issued
its decision but before this Court granted certiorari, the en-
tire incinerator facility in Roebuck was permanently closed,
dismantled, and put up for sale, and all discharges from
the facility permanently ceased. Respondent’s Suggestion of
Mootness 3.
We granted certiorari, 525 U. S. 1176 (1999), to resolve the
inconsistency between the Fourth Circuit’s decision in this

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
180 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
case and the decisions of several other Courts of Appeals,
which have held that a defendant’s compliance with its per-
mit after the commencement of litigation does not moot
claims for civil penalties under the Act. See, e. g., Atlantic
States Legal Foundation, Inc. v. Stroh Die Casting Co., 116
F. 3d 814, 820 (CA7), cert. denied, 522 U. S. 981 (1997); Natu-
ral Resources Defense Council, Inc. v. Texaco Rfg. and
Mktg., Inc., 2 F. 3d 493, 503–504 (CA3 1993); Atlantic States
Legal Foundation, Inc. v. Pan American Tanning Corp., 993
F. 2d 1017, 1020–1021 (CA2 1993); Atlantic States Legal
Foundation, Inc. v. Tyson Foods, Inc., 897 F. 2d 1128, 1135–
1136 (CA11 1990).
II
A
The Constitution’s case-or-controversy limitation on fed-
eral judicial authority, Art. III, § 2, underpins both our
standing and our mootness jurisprudence, but the two in-
quiries differ in respects critical to the proper resolution of
this case, so we address them separately. Because the
Court of Appeals was persuaded that the case had become
moot and so held, it simply assumed without deciding that
FOE had initial standing. See Arizonans for Official Eng-
lish v. Arizona, 520 U. S. 43, 66–67 (1997) (court may assume
without deciding that standing exists in order to analyze
mootness). But because we hold that the Court of Appeals
erred in declaring the case moot, we have an obligation to
assure ourselves that FOE had Article III standing at the
outset of the litigation. We therefore address the question
of standing before turning to mootness.
In Lujan v. Defenders of Wildlife, 504 U. S. 555, 560–561
(1992), we held that, to satisfy Article III’s standing require-
ments, a plaintiff must show (1) it has suffered an “injury in
fact” that is (a) concrete and particularized and (b) actual or
imminent, not conjectural or hypothetical; (2) the injury is
fairly traceable to the challenged action of the defendant; and

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
181 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
(3) it is likely, as opposed to merely speculative, that the
injury will be redressed by a favorable decision. An associ-
ation has standing to bring suit on behalf of its members
when its members would otherwise have standing to sue in
their own right, the interests at stake are germane to the
organization’s purpose, and neither the claim asserted nor
the relief requested requires the participation of individual
members in the lawsuit. Hunt v. Washington State Apple
Advertising Comm’n, 432 U. S. 333, 343 (1977).
Laidlaw contends first that FOE lacked standing from the
outset even to seek injunctive relief, because the plaintiff
organizations failed to show that any of their members had
sustained or faced the threat of any “injury in fact” from
Laidlaw’s activities. In support of this contention Laidlaw
points to the District Court’s finding, made in the course of
setting the penalty amount, that there had been “no demon-
strated proof of harm to the environment” from Laidlaw’s
mercury discharge violations. 956 F. Supp., at 602; see also
ibid. (“[T]he NPDES permit violations at issue in this citizen
suit did not result in any health risk or environmental
harm.”).
The relevant showing for purposes of Article III standing,
however, is not injury to the environment but injury to the
plaintiff. To insist upon the former rather than the latter
as part of the standing inquiry (as the dissent in essence
does, post, at 199–200) is to raise the standing hurdle higher
than the necessary showing for success on the merits in an
action alleging noncompliance with an NPDES permit. Fo-
cusing properly on injury to the plaintiff, the District Court
found that FOE had demonstrated sufficient injury to estab-
lish standing. App. in No. 97–1246 (CA4), at 207–208 (Tr. of
Hearing 39–40). For example, FOE member Kenneth Lee
Curtis averred in affidavits that he lived a half-mile from
Laidlaw’s facility; that he occasionally drove over the North
Tyger River, and that it looked and smelled polluted; and
that he would like to fish, camp, swim, and picnic in and near

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
182 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
the river between 3 and 15 miles downstream from the facil-
ity, as he did when he was a teenager, but would not do so
because he was concerned that the water was polluted by
Laidlaw’s discharges. Record, Doc. No. 71 (Exhs. 41, 42).
Curtis reaffirmed these statements in extensive deposition
testimony. For example, he testified that he would like to
fish in the river at a specific spot he used as a boy, but that he
would not do so now because of his concerns about Laidlaw’s
discharges. Ibid. (Exh. 43, at 52–53; Exh. 44, at 33).
Other members presented evidence to similar effect.
CLEAN member Angela Patterson attested that she lived
two miles from the facility; that before Laidlaw operated the
facility, she picnicked, walked, birdwatched, and waded in
and along the North Tyger River because of the natural
beauty of the area; that she no longer engaged in these activ-
ities in or near the river because she was concerned about
harmful effects from discharged pollutants; and that she and
her husband would like to purchase a home near the river
but did not intend to do so, in part because of Laidlaw’s dis-
charges. Record, Doc. No. 21 (Exh. 10). CLEAN member
Judy Pruitt averred that she lived one-quarter mile from
Laidlaw’s facility and would like to fish, hike, and picnic along
the North Tyger River, but has refrained from those ac-
tivities because of the discharges. Ibid. (Exh. 7). FOE
member Linda Moore attested that she lived 20 miles from
Roebuck, and would use the North Tyger River south of
Roebuck and the land surrounding it for recreational pur-
poses were she not concerned that the water contained
harmful pollutants. Record, Doc. No. 71 (Exhs. 45, 46). In
her deposition, Moore testified at length that she would hike,
picnic, camp, swim, boat, and drive near or in the river were
it not for her concerns about illegal discharges. Ibid. (Exh.
48, at 29, 36–37, 62–63, 72). CLEAN member Gail Lee at-
tested that her home, which is near Laidlaw’s facility, had a
lower value than similar homes located farther from the facil-
ity, and that she believed the pollutant discharges accounted

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
183 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
for some of the discrepancy. Record, Doc. No. 21 (Exh. 9).
Sierra Club member Norman Sharp averred that he had
canoed approximately 40 miles downstream of the Laidlaw
facility and would like to canoe in the North Tyger River
closer to Laidlaw’s discharge point, but did not do so because
he was concerned that the water contained harmful pollut-
ants. Ibid. (Exh. 8).
These sworn statements, as the District Court deter-
mined, adequately documented injury in fact. We have held
that environmental plaintiffs adequately allege injury in fact
when they aver that they use the affected area and are per-
sons “for whom the aesthetic and recreational values of the
area will be lessened” by the challenged activity. Sierra
Club v. Morton, 405 U. S. 727, 735 (1972). See also Defend-
ers of Wildlife, 504 U. S., at 562–563 (“Of course, the desire
to use or observe an animal species, even for purely esthetic
purposes, is undeniably a cognizable interest for purposes
of standing.”).
Our decision in Lujan v. National Wildlife Federation,
497 U. S. 871 (1990), is not to the contrary. In that case an
environmental organization assailed the Bureau of Land
Management’s “land withdrawal review program,” a pro-
gram covering millions of acres, alleging that the program
illegally opened up public lands to mining activities. The
defendants moved for summary judgment, challenging the
plaintiff organization’s standing to initiate the action under
the Administrative Procedure Act, 5 U. S. C. § 702. We held
that the plaintiff could not survive the summary judgment
motion merely by offering “averments which state only that
one of [the organization’s] members uses unspecified portions
of an immense tract of territory, on some portions of which
mining activity has occurred or probably will occur by virtue
of the governmental action.” 497 U. S., at 889.
In contrast, the affidavits and testimony presented by
FOE in this case assert that Laidlaw’s discharges, and the
affiant members’ reasonable concerns about the effects of

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
184 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
those discharges, directly affected those affiants’ recre-
ational, aesthetic, and economic interests. These submis-
sions present dispositively more than the mere “general
averments” and “conclusory allegations” found inadequate
in National Wildlife Federation. Id., at 888. Nor can the
affiants’ conditional statements—that they would use the
nearby North Tyger River for recreation if Laidlaw were not
discharging pollutants into it—be equated with the specula-
tive “ ‘some day’ intentions” to visit endangered species half-
way around the world that we held insufficient to show in-
jury in fact in Defenders of Wildlife. 504 U. S., at 564.
Los Angeles v. Lyons, 461 U. S. 95 (1983), relied on by the
dissent, post, at 199, does not weigh against standing in this
case. In Lyons, we held that a plaintiff lacked standing to
seek an injunction against the enforcement of a police choke-
hold policy because he could not credibly allege that he faced
a realistic threat from the policy. 461 U. S., at 107, n. 7. In
the footnote from Lyons cited by the dissent, we noted that
“[t]he reasonableness of Lyons’ fear is dependent upon the
likelihood of a recurrence of the allegedly unlawful conduct,”
and that his “subjective apprehensions” that such a recur-
rence would even take place were not enough to support
standing. Id., at 108, n. 8. Here, in contrast, it is undis-
puted that Laidlaw’s unlawful conduct—discharging pollut-
ants in excess of permit limits—was occurring at the time
the complaint was filed. Under Lyons, then, the only “sub-
jective” issue here is “[t]he reasonableness of [the] fear” that
led the affiants to respond to that concededly ongoing con-
duct by refraining from use of the North Tyger River and
surrounding areas. Unlike the dissent, post, at 200, we see
nothing “improbable” about the proposition that a company’s
continuous and pervasive illegal discharges of pollutants into
a river would cause nearby residents to curtail their recre-
ational use of that waterway and would subject them to
other economic and aesthetic harms. The proposition is en-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
185 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
tirely reasonable, the District Court found it was true in this
case, and that is enough for injury in fact.
Laidlaw argues next that even if FOE had standing to
seek injunctive relief, it lacked standing to seek civil penal-
ties. Here the asserted defect is not injury but redressabil-
ity. Civil penalties offer no redress to private plaintiffs,
Laidlaw argues, because they are paid to the Government,
and therefore a citizen plaintiff can never have standing to
seek them.
Laidlaw is right to insist that a plaintiff must demonstrate
standing separately for each form of relief sought. See, e. g.,
Lyons, 461 U. S., at 109 (notwithstanding the fact that plain-
tiff had standing to pursue damages, he lacked standing to
pursue injunctive relief); see also Lewis v. Casey, 518 U. S.
343, 358, n. 6 (1996) (“[S]tanding is not dispensed in gross.”).
But it is wrong to maintain that citizen plaintiffs facing ongo-
ing violations never have standing to seek civil penalties.
We have recognized on numerous occasions that “all civil
penalties have some deterrent effect.” Hudson v. United
States, 522 U. S. 93, 102 (1997); see also, e. g., Department of
Revenue of Mont. v. Kurth Ranch, 511 U. S. 767, 778 (1994).
More specifically, Congress has found that civil penalties in
Clean Water Act cases do more than promote immediate
compliance by limiting the defendant’s economic incentive to
delay its attainment of permit limits; they also deter future
violations. This congressional determination warrants judi-
cial attention and respect. “The legislative history of the
Act reveals that Congress wanted the district court to con-
sider the need for retribution and deterrence, in addition to
restitution, when it imposed civil penalties. . . . [The district
court may] seek to deter future violations by basing the pen-
alty on its economic impact.” Tull v. United States, 481
U. S. 412, 422–423 (1987).
It can scarcely be doubted that, for a plaintiff who is in-
jured or faces the threat of future injury due to illegal con-
duct ongoing at the time of suit, a sanction that effectively

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
186 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
abates that conduct and prevents its recurrence provides a
form of redress. Civil penalties can fit that description. To
the extent that they encourage defendants to discontinue
current violations and deter them from committing future
ones, they afford redress to citizen plaintiffs who are injured
or threatened with injury as a consequence of ongoing un-
lawful conduct.
The dissent argues that it is the availability rather than
the imposition of civil penalties that deters any particular
polluter from continuing to pollute. Post, at 207–208. This
argument misses the mark in two ways. First, it overlooks
the interdependence of the availability and the imposition; a
threat has no deterrent value unless it is credible that it will
be carried out. Second, it is reasonable for Congress to con-
clude that an actual award of civil penalties does in fact bring
with it a significant quantum of deterrence over and above
what is achieved by the mere prospect of such penalties. A
would-be polluter may or may not be dissuaded by the exist-
ence of a remedy on the books, but a defendant once hit in
its pocketbook will surely think twice before polluting again.2
We recognize that there may be a point at which the deter-
rent effect of a claim for civil penalties becomes so insubstan-
tial or so remote that it cannot support citizen standing.
The fact that this vanishing point is not easy to ascertain
does not detract from the deterrent power of such penalties
in the ordinary case. Justice Frankfurter’s observations for
2 The dissent suggests that there was little deterrent work for civil pen-
alties to do in this case because the lawsuit brought against Laidlaw by
DHEC had already pushed the level of deterrence to “near the top of the
graph.” Post, at 208. This suggestion ignores the District Court’s spe-
cific finding that the penalty agreed to by Laidlaw and DHEC was far too
low to remove Laidlaw’s economic benefit from noncompliance, and thus
was inadequate to deter future violations. 890 F. Supp. 470, 491–494, 497–
498 (SC 1995). And it begins to look especially farfetched when one re-
calls that Laidlaw itself prompted the DHEC lawsuit, paid the filing fee,
and drafted the complaint. See supra, at 176–177, 178, n. 1.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
187 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
the Court, made in a different context nearly 60 years ago,
hold true here as well:
“How to effectuate policy—the adaptation of means to
legitimately sought ends—is one of the most intractable
of legislative problems. Whether proscribed conduct is
to be deterred by qui tam action or triple damages or
injunction, or by criminal prosecution, or merely by de-
fense to actions in contract, or by some, or all, of these
remedies in combination, is a matter within the legisla-
ture’s range of choice. Judgment on the deterrent ef-
fect of the various weapons in the armory of the law can
lay little claim to scientific basis.” Tigner v. Texas, 310
U. S. 141, 148 (1940).3
In this case we need not explore the outer limits of the prin-
ciple that civil penalties provide sufficient deterrence to sup-
port redressability. Here, the civil penalties sought by FOE
carried with them a deterrent effect that made it likely, as
opposed to merely speculative, that the penalties would re-
dress FOE’s injuries by abating current violations and pre-
venting future ones—as the District Court reasonably found
when it assessed a penalty of $405,800. 956 F. Supp., at
610–611.
Laidlaw contends that the reasoning of our decision in
Steel Co. directs the conclusion that citizen plaintiffs have no
standing to seek civil penalties under the Act. We disagree.
Steel Co. established that citizen suitors lack standing to seek
civil penalties for violations that have abated by the time of
suit. 523 U. S., at 106–107. We specifically noted in that
case that there was no allegation in the complaint of any
continuing or imminent violation, and that no basis for such
an allegation appeared to exist. Id., at 108; see also Gwalt-
ney, 484 U. S., at 59 (“the harm sought to be addressed by
3 In Tigner the Court rejected an equal protection challenge to a statu-
tory provision exempting agricultural producers from the reach of the
Texas antitrust laws.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
188 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
the citizen suit lies in the present or the future, not in the
past”). In short, Steel Co. held that private plaintiffs, unlike
the Federal Government, may not sue to assess penalties for
wholly past violations, but our decision in that case did not
reach the issue of standing to seek penalties for violations
that are ongoing at the time of the complaint and that could
continue into the future if undeterred.4
4 In insisting that the redressability requirement is not met, the dissent
relies heavily on Linda R. S. v. Richard D., 410 U. S. 614 (1973). That
reliance is sorely misplaced. In Linda R. S., the mother of an out-of-
wedlock child filed suit to force a district attorney to bring a criminal
prosecution against the absentee father for failure to pay child support.
Id., at 616. In finding that the mother lacked standing to seek this ex-
traordinary remedy, the Court drew attention to “the special status of
criminal prosecutions in our system,” id., at 619, and carefully limited its
holding to the “unique context of a challenge to [the nonenforcement of] a
criminal statute,” id., at 617. Furthermore, as to redressability, the relief
sought in Linda R. S.—a prosecution which, if successful, would automati-
cally land the delinquent father in jail for a fixed term, id., at 618, with
predictably negative effects on his earning power—would scarcely remedy
the plaintiff ’s lack of child support payments. In this regard, the Court
contrasted “the civil contempt model whereby the defendant ‘keeps the
keys to the jail in his own pocket’ and may be released whenever he com-
plies with his legal obligations.” Ibid. The dissent’s contention, post, at
204, that “precisely the same situation exists here” as in Linda R. S. is, to
say the least, extravagant.
Putting aside its mistaken reliance on Linda R. S., the dissent’s broader
charge that citizen suits for civil penalties under the Act carry “grave
implications for democratic governance,” post, at 202, seems to us over-
drawn. Certainly the Federal Executive Branch does not share the dis-
sent’s view that such suits dissipate its authority to enforce the law. In
fact, the Department of Justice has endorsed this citizen suit from the
outset, submitting amicus briefs in support of FOE in the District Court,
the Court of Appeals, and this Court. See supra, at 177, 179. As we
have already noted, supra, at 175, the Federal Government retains the
power to foreclose a citizen suit by undertaking its own action. 33
U. S. C. § 1365(b)(1)(B). And if the Executive Branch opposes a particular
citizen suit, the statute allows the Administrator of the EPA to “intervene
as a matter of right” and bring the Government’s views to the attention
of the court. § 1365(c)(2).

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
189 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
B
Satisfied that FOE had standing under Article III to bring
this action, we turn to the question of mootness.
The only conceivable basis for a finding of mootness in this
case is Laidlaw’s voluntary conduct—either its achievement
by August 1992 of substantial compliance with its NPDES
permit or its more recent shutdown of the Roebuck facility.
It is well settled that “a defendant’s voluntary cessation of a
challenged practice does not deprive a federal court of its
power to determine the legality of the practice.” City of
Mesquite, 455 U. S., at 289. “[I]f it did, the courts would
be compelled to leave ‘[t]he defendant . . . free to return to
his old ways.’ ” Id., at 289, n. 10 (citing United States v.
W. T. Grant Co., 345 U. S. 629, 632 (1953)). In accordance
with this principle, the standard we have announced for de-
termining whether a case has been mooted by the defend-
ant’s voluntary conduct is stringent: “A case might become
moot if subsequent events made it absolutely clear that the
allegedly wrongful behavior could not reasonably be ex-
pected to recur.” United States v. Concentrated Phosphate
Export Assn., Inc., 393 U. S. 199, 203 (1968). The “heavy
burden of persua[ding]” the court that the challenged con-
duct cannot reasonably be expected to start up again lies
with the party asserting mootness. Ibid.
The Court of Appeals justified its mootness disposition by
reference to Steel Co., which held that citizen plaintiffs lack
standing to seek civil penalties for wholly past violations.
In relying on Steel Co., the Court of Appeals confused moot-
ness with standing. The confusion is understandable, given
this Court’s repeated statements that the doctrine of moot-
ness can be described as “the doctrine of standing set in a
time frame: The requisite personal interest that must exist
at the commencement of the litigation (standing) must con-
tinue throughout its existence (mootness).” Arizonans for
Official English, 520 U. S., at 68, n. 22 (quoting United States
Parole Comm’n v. Geraghty, 445 U. S. 388, 397 (1980), in turn

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
190 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
quoting Monaghan, Constitutional Adjudication: The Who
and When, 82 Yale L. J. 1363, 1384 (1973)) (internal quotation
marks omitted).
Careful reflection on the long-recognized exceptions to
mootness, however, reveals that the description of mootness
as “standing set in a time frame” is not comprehensive. As
just noted, a defendant claiming that its voluntary compli-
ance moots a case bears the formidable burden of showing
that it is absolutely clear the allegedly wrongful behavior
could not reasonably be expected to recur. Concentrated
Phosphate Export Assn., 393 U. S., at 203. By contrast, in
a lawsuit brought to force compliance, it is the plaintiff ’s
burden to establish standing by demonstrating that, if un-
checked by the litigation, the defendant’s allegedly wrongful
behavior will likely occur or continue, and that the “threat-
ened injury [is] certainly impending.” Whitmore v. Arkan-
sas, 495 U. S. 149, 158 (1990) (citations and internal quotation
marks omitted). Thus, in Lyons, as already noted, we held
that a plaintiff lacked initial standing to seek an injunction
against the enforcement of a police chokehold policy because
he could not credibly allege that he faced a realistic threat
arising from the policy. 461 U. S., at 105–110. Elsewhere
in the opinion, however, we noted that a citywide morato-
rium on police chokeholds—an action that surely diminished
the already slim likelihood that any particular individual
would be choked by police—would not have mooted an other-
wise valid claim for injunctive relief, because the moratorium
by its terms was not permanent. Id., at 101. The plain les-
son of these cases is that there are circumstances in which
the prospect that a defendant will engage in (or resume)
harmful conduct may be too speculative to support standing,
but not too speculative to overcome mootness.
Furthermore, if mootness were simply “standing set in a
time frame,” the exception to mootness that arises when the
defendant’s allegedly unlawful activity is “capable of repeti-
tion, yet evading review,” could not exist. When, for exam-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
191 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
ple, a mentally disabled patient files a lawsuit challenging
her confinement in a segregated institution, her postcom-
plaint transfer to a community-based program will not moot
the action, Olmstead v. L. C., 527 U. S. 581, 594, n. 6 (1999),
despite the fact that she would have lacked initial standing
had she filed the complaint after the transfer. Standing ad-
mits of no similar exception; if a plaintiff lacks standing at
the time the action commences, the fact that the dispute is
capable of repetition yet evading review will not entitle the
complainant to a federal judicial forum. See Steel Co., 523
U. S., at 109 (“ ‘the mootness exception for disputes capable
of repetition yet evading review . . . will not revive a dispute
which became moot before the action commenced’ ”) (quoting
Renne v. Geary, 501 U. S. 312, 320 (1991)).
We acknowledged the distinction between mootness and
standing most recently in Steel Co.:
“The United States . . . argues that the injunctive
relief does constitute remediation because ‘there is a
presumption of [future] injury when the defendant
has voluntarily ceased its illegal activity in response
to litigation,’ even if that occurs before a complaint is
filed. . . . This makes a sword out of a shield. The ‘pre-
sumption’ the Government refers to has been applied to
refute the assertion of mootness by a defendant who,
when sued in a complaint that alleges present or threat-
ened injury, ceases the complained-of activity. . . . It is
an immense and unacceptable stretch to call the pre-
sumption into service as a substitute for the allegation of
present or threatened injury upon which initial standing
must be based.” 523 U. S., at 109.
Standing doctrine functions to ensure, among other things,
that the scarce resources of the federal courts are devoted
to those disputes in which the parties have a concrete stake.
In contrast, by the time mootness is an issue, the case has
been brought and litigated, often (as here) for years. To

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
192 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
abandon the case at an advanced stage may prove more
wasteful than frugal. This argument from sunk costs 5 does
not license courts to retain jurisdiction over cases in which
one or both of the parties plainly lack a continuing interest,
as when the parties have settled or a plaintiff pursuing a
nonsurviving claim has died. See, e. g., DeFunis v. Ode-
gaard, 416 U. S. 312 (1974) (per curiam) (non-class-action
challenge to constitutionality of law school admissions proc-
ess mooted when plaintiff, admitted pursuant to preliminary
injunction, neared graduation and defendant law school con-
ceded that, as a matter of ordinary school policy, plaintiff
would be allowed to finish his final term); Arizonans, 520
U. S., at 67 (non-class-action challenge to state constitutional
amendment declaring English the official language of the
State became moot when plaintiff, a state employee who
sought to use her bilingual skills, left state employment).
But the argument surely highlights an important difference
between the two doctrines. See generally Honig v. Doe, 484
U. S. 305, 329–332 (1988) (Rehnquist, C. J., concurring).
In its brief, Laidlaw appears to argue that, regardless of
the effect of Laidlaw’s compliance, FOE doomed its own civil
penalty claim to mootness by failing to appeal the District
Court’s denial of injunctive relief. Brief for Respondent 14–
17. This argument misconceives the statutory scheme.
Under § 1365(a), the district court has discretion to deter-
mine which form of relief is best suited, in the particular
case, to abate current violations and deter future ones. “[A]
federal judge sitting as chancellor is not mechanically obli-
gated to grant an injunction for every violation of law.”
5 Of course we mean sunk costs to the judicial system, not to the liti-
gants. Lewis v. Continental Bank Corp., 494 U. S. 472 (1990) (cited by
the dissent, post, at 213), dealt with the latter, noting that courts should
use caution to avoid carrying forward a moot case solely to vindicate a
plaintiff ’s interest in recovering attorneys’ fees.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
193 Cite as: 528 U. S. 167 (2000)
Opinion of the Court
Weinberger v. Romero-Barcelo, 456 U. S. 305, 313 (1982).
Denial of injunctive relief does not necessarily mean that the
district court has concluded there is no prospect of future
violations for civil penalties to deter. Indeed, it meant no
such thing in this case. The District Court denied injunc-
tive relief, but expressly based its award of civil penalties on
the need for deterrence. See 956 F. Supp., at 610–611. As
the dissent notes, post, at 205, federal courts should aim to
ensure “ ‘the framing of relief no broader than required by
the precise facts.’ ” Schlesinger v. Reservists Comm. to
Stop the War, 418 U. S. 208, 222 (1974). In accordance with
this aim, a district court in a Clean Water Act citizen suit
properly may conclude that an injunction would be an exces-
sively intrusive remedy, because it could entail continuing
superintendence of the permit holder’s activities by a federal
court—a process burdensome to court and permit holder
alike. See City of Mesquite, 455 U. S., at 289 (although the
defendant’s voluntary cessation of the challenged practice
does not moot the case, “[s]uch abandonment is an important
factor bearing on the question whether a court should exer-
cise its power to enjoin the defendant from renewing the
practice”).
Laidlaw also asserts, in a supplemental suggestion of
mootness, that the closure of its Roebuck facility, which took
place after the Court of Appeals issued its decision, mooted
the case. The facility closure, like Laidlaw’s earlier achieve-
ment of substantial compliance with its permit requirements,
might moot the case, but—we once more reiterate—only if
one or the other of these events made it absolutely clear that
Laidlaw’s permit violations could not reasonably be expected
to recur. Concentrated Phosphate Export Assn., 393 U. S.,
at 203. The effect of both Laidlaw’s compliance and the fa-
cility closure on the prospect of future violations is a dis-
puted factual matter. FOE points out, for example—and
Laidlaw does not appear to contest—that Laidlaw retains its

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
194 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Opinion of the Court
NPDES permit. These issues have not been aired in the
lower courts; they remain open for consideration on remand.6
C
FOE argues that it is entitled to attorneys’ fees on the
theory that a plaintiff can be a “prevailing party” for pur-
poses of 33 U. S. C. § 1365(d) if it was the “catalyst” that trig-
gered a favorable outcome. In the decision under review,
the Court of Appeals noted that its Circuit precedent con-
strued our decision in Farrar v. Hobby, 506 U. S. 103 (1992),
to require rejection of that theory. 149 F. 3d, at 307, n. 5
(citing S–1 & S–2 v. State Bd. of Ed. of N. C., 21 F. 3d 49, 51
(CA4 1994) (en banc)). Cf. Foreman v. Dallas County, 193
F. 3d 314, 320 (CA5 1999) (stating, in dicta, that “[a]fter
Farrar . . . the continuing validity of the catalyst theory is
in serious doubt”).
Farrar acknowledged that a civil rights plaintiff awarded
nominal damages may be a “prevailing party” under 42
U. S. C. § 1988. 506 U. S., at 112. The case involved no cat-
alytic effect. Recognizing that the issue was not presented
for this Court’s decision in Farrar, several Courts of Appeals
have expressly concluded that Farrar did not repudiate the
catalyst theory. See Marbley v. Bane, 57 F. 3d 224, 234
(CA2 1995); Baumgartner v. Harrisburg Housing Authority,
21 F. 3d 541, 546–550 (CA3 1994); Zinn v. Shalala, 35 F. 3d
273, 276 (CA7 1994); Little Rock School Dist. v. Pulaski
County Special Sch. Dist., #1, 17 F. 3d 260, 263, n. 2 (CA8
1994); Kilgour v. Pasadena, 53 F. 3d 1007, 1010 (CA9 1995);
6 We note that it is far from clear that vacatur of the District Court’s
judgment would be the appropriate response to a finding of mootness on
appeal brought about by the voluntary conduct of the party that lost
in the District Court. See U. S. Bancorp Mortgage Co. v. Bonner Mall
Partnership, 513 U. S. 18 (1994) (mootness attributable to a voluntary act
of a nonprevailing party ordinarily does not justify vacatur of a judgment
under review); see also Walling v. James V. Reuter, Inc., 321 U. S. 671
(1944).

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
195 Cite as: 528 U. S. 167 (2000)
Stevens, J., concurring
Beard v. Teska, 31 F. 3d 942, 951–952 (CA10 1994); Morris v.
West Palm Beach, 194 F. 3d 1203, 1207 (CA11 1999). Other
Courts of Appeals have likewise continued to apply the cata-
lyst theory notwithstanding Farrar. Paris v. United States
Dept. of Housing and Urban Development, 988 F. 2d 236,
238 (CA1 1993); Citizens Against Tax Waste v. Westerville
City School, 985 F. 2d 255, 257 (CA6 1993).
It would be premature, however, for us to address the con-
tinuing validity of the catalyst theory in the context of this
case. The District Court, in an order separate from the one
in which it imposed civil penalties against Laidlaw, stayed
the time for a petition for attorneys’ fees until the time for
appeal had expired or, if either party appealed, until the ap-
peal was resolved. See 149 F. 3d, at 305 (describing order
staying time for attorneys’ fees petition). In the opinion ac-
companying its order on penalties, the District Court stated
only that “this court has considered that Laidlaw will be re-
quired to reimburse plaintiffs for a significant amount of
legal fees,” and referred to “potential fee awards.” 956
F. Supp., at 610–611. Thus, when the Court of Appeals ad-
dressed the availability of counsel fees in this case, no order
was before it either denying or awarding fees. It is for the
District Court, not this Court, to address in the first instance
any request for reimbursement of costs, including fees.
* * *
For the reasons stated, the judgment of the United States
Court of Appeals for the Fourth Circuit is reversed, and the
case is remanded for further proceedings consistent with
this opinion.
It is so ordered.
Justice Stevens, concurring.
Although the Court has identified a sufficient reason for
rejecting the Court of Appeals’ mootness determination, it
is important also to note that the case would not be moot

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
196 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Stevens, J., concurring
even if it were absolutely clear that respondent had gone out
of business and posed no threat of future permit violations.
The District Court entered a valid judgment requiring re-
spondent to pay a civil penalty of $405,800 to the United
States. No postjudgment conduct of respondent could ret-
roactively invalidate that judgment. A record of voluntary
postjudgment compliance that would justify a decision that
injunctive relief is unnecessary, or even a decision that any
claim for injunctive relief is now moot, would not warrant
vacation of the valid money judgment.
Furthermore, petitioners’ claim for civil penalties would
not be moot even if it were absolutely clear that respondent’s
violations could not reasonably be expected to recur because
respondent achieved substantial compliance with its permit
requirements after petitioners filed their complaint but be-
fore the District Court entered judgment. As the Courts of
Appeals (other than the court below) have uniformly con-
cluded, a polluter’s voluntary postcomplaint cessation of an
alleged violation will not moot a citizen-suit claim for civil
penalties even if it is sufficient to moot a related claim for
injunctive or declaratory relief.* This conclusion is consist-
ent with the structure of the Clean Water Act, which at-
taches liability for civil penalties at the time a permit viola-
tion occurs. 33 U. S. C. § 1319(d) (“Any person who violates
*Comfort Lake Assn. v. Dresel Contracting, Inc., 138 F. 3d 351, 356
(CA8 1998); Atlantic States Legal Foundation, Inc. v. Stroh Die Casting
Co., 116 F. 3d 814, 820 (CA7), cert. denied, 522 U. S. 981 (1997); Natural
Resources Defense Council v. Texaco Refining & Mktg., Inc., 2 F. 3d 493,
502–503 (CA3 1993); Atlantic States Legal Foundation, Inc. v. Pan Am.
Tanning Corp., 993 F. 2d 1017, 1020–1021 (CA2 1993); Atlantic States
Legal Foundation, Inc. v. Tyson Foods, Inc., 897 F. 2d 1128, 1134–1137
(CA11 1990); Chesapeake Bay Foundation, Inc. v. Gwaltney of Smithfield,
Ltd., 890 F. 2d 690, 696–697 (CA4 1989). Cf. Powell v. McCormack, 395
U. S. 486, 496, n. 8 (1969) (“Where several forms of relief are requested
and one of these requests subsequently becomes moot, the Court has still
considered the remaining requests”).

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
197 Cite as: 528 U. S. 167 (2000)
Kennedy, J., concurring
[certain provisions of the Act or certain permit conditions
and limitations] shall be subject to a civil penalty . . .”). It
is also consistent with the character of civil penalties, which,
for purposes of mootness analysis, should be equated with
punitive damages rather than with injunctive or declaratory
relief. See Tull v. United States, 481 U. S. 412, 422–423
(1987). No one contends that a defendant’s postcomplaint
conduct could moot a claim for punitive damages; civil penal-
ties should be treated the same way.
The cases cited by the Court in its discussion of the moot-
ness issue all involved requests for injunctive or declaratory
relief. In only one, Los Angeles v. Lyons, 461 U. S. 95
(1983), did the plaintiff seek damages, and in that case the
opinion makes it clear that the inability to obtain injunctive
relief would have no impact on the damages claim. Id., at
105, n. 6, 109. There is no precedent, either in our jurispru-
dence, or in any other of which I am aware, that provides
any support for the suggestion that postcomplaint factual de-
velopments that might moot a claim for injunctive or declara-
tory relief could either moot a claim for monetary relief or
retroactively invalidate a valid money judgment.
Justice Kennedy, concurring.
Difficult and fundamental questions are raised when we
ask whether exactions of public fines by private litigants, and
the delegation of Executive power which might be inferable
from the authorization, are permissible in view of the respon-
sibilities committed to the Executive by Article II of the
Constitution of the United States. The questions presented
in the petition for certiorari did not identify these issues
with particularity; and neither the Court of Appeals in de-
ciding the case nor the parties in their briefing before this
Court devoted specific attention to the subject. In my view
these matters are best reserved for a later case. With this
observation, I join the opinion of the Court.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
198 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
Justice Scalia, with whom Justice Thomas joins,
dissenting.
The Court begins its analysis by finding injury in fact
on the basis of vague affidavits that are undermined by the
District Court’s express finding that Laidlaw’s discharges
caused no demonstrable harm to the environment. It then
proceeds to marry private wrong with public remedy in a
union that violates traditional principles of federal stand-
ing—thereby permitting law enforcement to be placed in the
hands of private individuals. Finally, the Court suggests
that to avoid mootness one needs even less of a stake in the
outcome than the Court’s watered-down requirements for
initial standing. I dissent from all of this.
I
Plaintiffs, as the parties invoking federal jurisdiction, have
the burden of proof and persuasion as to the existence of
standing. Lujan v. Defenders of Wildlife, 504 U. S. 555, 561
(1992) (hereinafter Lujan); FW/PBS, Inc. v. Dallas, 493 U. S.
215, 231 (1990). The plaintiffs in this case fell far short of
carrying their burden of demonstrating injury in fact. The
Court cites affiants’ testimony asserting that their enjoy-
ment of the North Tyger River has been diminished due to
“concern” that the water was polluted, and that they “be-
lieved” that Laidlaw’s mercury exceedances had reduced the
value of their homes. Ante, at 181–183. These averments
alone cannot carry the plaintiffs’ burden of demonstrating
that they have suffered a “concrete and particularized” in-
jury, Lujan, 504 U. S., at 560. General allegations of injury
may suffice at the pleading stage, but at summary judgment
plaintiffs must set forth “specific facts” to support their
claims. Id., at 561. And where, as here, the case has pro-
ceeded to judgment, those specific facts must be “ ‘supported
adequately by the evidence adduced at trial,’ ” ibid. (quoting
Gladstone, Realtors v. Village of Bellwood, 441 U. S. 91, 115,
n. 31 (1979)). In this case, the affidavits themselves are

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
199 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
woefully short on “specific facts,” and the vague allegations
of injury they do make are undermined by the evidence ad-
duced at trial.
Typically, an environmental plaintiff claiming injury due
to discharges in violation of the Clean Water Act argues that
the discharges harm the environment, and that the harm to
the environment injures him. This route to injury is barred
in the present case, however, since the District Court con-
cluded after considering all the evidence that there had been
“no demonstrated proof of harm to the environment,” 956
F. Supp. 588, 602 (SC 1997), that the “permit violations at
issue in this citizen suit did not result in any health risk or
environmental harm,” ibid., that “[a]ll available data . . . fail
to show that Laidlaw’s actual discharges have resulted in
harm to the North Tyger River,” id., at 602–603, and that
“the overall quality of the river exceeds levels necessary to
support . . . recreation in and on the water,” id., at 600.
The Court finds these conclusions unproblematic for stand-
ing, because “[t]he relevant showing for purposes of Article
III standing . . . is not injury to the environment but injury
to the plaintiff.” Ante, at 181. This statement is correct,
as far as it goes. We have certainly held that a demonstra-
tion of harm to the environment is not enough to satisfy the
injury-in-fact requirement unless the plaintiff can demon-
strate how he personally was harmed. E. g., Lujan, supra,
at 563. In the normal course, however, a lack of demonstra-
ble harm to the environment will translate, as it plainly does
here, into a lack of demonstrable harm to citizen plaintiffs.
While it is perhaps possible that a plaintiff could be harmed
even though the environment was not, such a plaintiff would
have the burden of articulating and demonstrating the na-
ture of that injury. Ongoing “concerns” about the environ-
ment are not enough, for “[i]t is the reality of the threat of
repeated injury that is relevant to the standing inquiry, not
the plaintiff ’s subjective apprehensions,” Los Angeles v.
Lyons, 461 U. S. 95, 107, n. 8 (1983). At the very least, in

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
200 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
the present case, one would expect to see evidence support-
ing the affidavits’ bald assertions regarding decreasing
recreational usage and declining home values, as well as
evidence for the improbable proposition that Laidlaw’s
violations, even though harmless to the environment, are
somehow responsible for these effects. Cf. Gladstone,
supra, at 115 (noting that standing could be established by
“convincing evidence” that a decline in real estate values was
attributable to the defendant’s conduct). Plaintiffs here
have made no attempt at such a showing, but rely entirely
upon unsupported and unexplained affidavit allegations of
“concern.”
Indeed, every one of the affiants deposed by Laidlaw
cast into doubt the (in any event inadequate) proposition
that subjective “concerns” actually affected their conduct.
Linda Moore, for example, said in her affidavit that she
would use the affected waterways for recreation if it were
not for her concern about pollution. Record, Doc. No. 71
(Exhs. 45, 46). Yet she testified in her deposition that she
had been to the river only twice, once in 1980 (when she
visited someone who lived by the river) and once after this
suit was filed. Record, Doc. No. 62 (Moore Deposition 23–
24). Similarly, Kenneth Lee Curtis, who claimed he was in-
jured by being deprived of recreational activity at the river,
admitted that he had not been to the river since he was “a
kid,” ibid. (Curtis Deposition, pt. 2, p. 38), and when asked
whether the reason he stopped visiting the river was because
of pollution, answered “no,” id., at 39. As to Curtis’s claim
that the river “looke[d] and smell[ed] polluted,” this condi-
tion, if present, was surely not caused by Laidlaw’s dis-
charges, which according to the District Court “did not
result in any health risk or environmental harm.” 956
F. Supp., at 602. The other affiants cited by the Court were
not deposed, but their affidavits state either that they would
use the river if it were not polluted or harmful (as the court
subsequently found it is not), Record, Doc. No. 21 (Exhs. 7,

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
201 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
8, and 9), or said that the river looks polluted (which is also
incompatible with the court’s findings), ibid. (Exh. 10).
These affiants have established nothing but “subjective
apprehensions.”
The Court is correct that the District Court explicitly
found standing—albeit “by the very slimmest of margins,”
and as “an awfully close call.” App. in No. 97–1246 (CA4),
pp. 207–208 (Tr. of Hearing 39–40 (June 30, 1993)). That
cautious finding, however, was made in 1993, long before the
court’s 1997 conclusion that Laidlaw’s discharges did not
harm the environment. As we have previously recognized,
an initial conclusion that plaintiffs have standing is subject
to reexamination, particularly if later evidence proves incon-
sistent with that conclusion. Gladstone, 441 U. S., at 115,
and n. 31; Wyoming v. Oklahoma, 502 U. S. 437, 446 (1992).
Laidlaw challenged the existence of injury in fact on appeal
to the Fourth Circuit, but that court did not reach the ques-
tion. Thus no lower court has reviewed the injury-in-fact
issue in light of the extensive studies that led the District
Court to conclude that the environment was not harmed by
Laidlaw’s discharges.
Inexplicably, the Court is untroubled by this, but proceeds
to find injury in fact in the most casual fashion, as though it
is merely confirming a careful analysis made below. Al-
though we have previously refused to find standing based on
the “conclusory allegations of an affidavit,” Lujan v. Na-
tional Wildlife Federation, 497 U. S. 871, 888 (1990), the
Court is content to do just that today. By accepting plain-
tiffs’ vague, contradictory, and unsubstantiated allegations of
“concern” about the environment as adequate to prove injury
in fact, and accepting them even in the face of a finding that
the environment was not demonstrably harmed, the Court
makes the injury-in-fact requirement a sham. If there are
permit violations, and a member of a plaintiff environmental
organization lives near the offending plant, it would be diffi-
cult not to satisfy today’s lenient standard.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
202 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
II
The Court’s treatment of the redressability requirement—
which would have been unnecessary if it resolved the
injury-in-fact question correctly—is equally cavalier. As
discussed above, petitioners allege ongoing injury consisting
of diminished enjoyment of the affected waterways and de-
creased property values. They allege that these injuries
are caused by Laidlaw’s continuing permit violations. But
the remedy petitioners seek is neither recompense for their
injuries nor an injunction against future violations. In-
stead, the remedy is a statutorily specified “penalty” for past
violations, payable entirely to the United States Treasury.
Only last Term, we held that such penalties do not redress
any injury a citizen plaintiff has suffered from past viola-
tions. Steel Co. v. Citizens for Better Environment, 523
U. S. 83, 106–107 (1998). The Court nonetheless finds the
redressability requirement satisfied here, distinguishing
Steel Co. on the ground that in this case petitioners allege
ongoing violations; payment of the penalties, it says, will
remedy petitioners’ injury by deterring future violations by
Laidlaw. Ante, at 185–186. It holds that a penalty payable
to the public “remedies” a threatened private harm, and suf-
fices to sustain a private suit.
That holding has no precedent in our jurisprudence, and
takes this Court beyond the “cases and controversies” that
Article III of the Constitution has entrusted to its resolution.
Even if it were appropriate, moreover, to allow Article III’s
remediation requirement to be satisfied by the indirect pri-
vate consequences of a public penalty, those consequences
are entirely too speculative in the present case. The new
standing law that the Court makes—like all expansions of
standing beyond the traditional constitutional limits—has
grave implications for democratic governance. I shall dis-
cuss these three points in turn.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
203 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
A
In Linda R. S. v. Richard D., 410 U. S. 614 (1973), the plain-
tiff, mother of an illegitimate child, sought, on behalf of her-
self, her child, and all others similarly situated, an injunction
against discriminatory application of Art. 602 of the Texas
Penal Code. Although that provision made it a misde-
meanor for “any parent” to refuse to support his or her minor
children under 18 years of age, it was enforced only against
married parents. That refusal, the plaintiff contended, de-
prived her and her child of the equal protection of the law
by denying them the deterrent effect of the statute upon the
father’s failure to fulfill his support obligation. The Court
held that there was no Article III standing. There was no
“ ‘direct’ relationship,” it said, “between the alleged injury
and the claim sought to be adjudicated,” since “[t]he prospect
that prosecution will, at least in the future, result in payment
of support can, at best, be termed only speculative.” Id., at
618. “[Our cases] demonstrate that, in American jurispru-
dence at least, a private citizen lacks a judicially cognizable
interest in the prosecution or nonprosecution of another.”
Id., at 619.
Although the Court in Linda R. S. recited the “logical
nexus” analysis of Flast v. Cohen, 392 U. S. 83 (1968), which
has since fallen into desuetude, “it is clear that standing was
denied . . . because of the unlikelihood that the relief re-
quested would redress appellant’s claimed injury.” Duke
Power Co. v. Carolina Environmental Study Group, Inc.,
438 U. S. 59, 79, n. 24 (1978). There was no “logical nexus”
between nonenforcement of the statute and Linda R. S.’s fail-
ure to receive support payments because “[t]he prospect that
prosecution will . . . result in payment of support” was “spec-
ulative,” Linda R. S., supra, at 618—that is to say, it was
uncertain whether the relief would prevent the injury.1 Of
1 The decision in Linda R. S. did not turn, as today’s opinion imagina-
tively suggests, on the father’s short-term inability to pay support if im-
prisoned. Ante, at 188, n. 4. The Court’s only comment upon the impris-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
204 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
course precisely the same situation exists here. The princi-
ple that “in American jurisprudence . . . a private citizen
lacks a judicially cognizable interest in the prosecution or
nonprosecution of another” applies no less to prosecution for
civil penalties payable to the State than to prosecution for
criminal penalties owing to the State.
The Court’s opinion reads as though the only purpose and
effect of the redressability requirement is to assure that the
plaintiff receive some of the benefit of the relief that a court
orders. That is not so. If it were, a federal tort plaintiff
fearing repetition of the injury could ask for tort damages to
be paid not only to himself but to other victims as well, on
the theory that those damages would have at least some de-
terrent effect beneficial to him. Such a suit is preposterous
because the “remediation” that is the traditional business
of Anglo-American courts is relief specifically tailored to the
plaintiff ’s injury, and not any sort of relief that has some
incidental benefit to the plaintiff. Just as a “generalized
grievance” that affects the entire citizenry cannot satisfy the
injury-in-fact requirement even though it aggrieves the
plaintiff along with everyone else, see Lujan, 504 U. S., at
573–574, so also a generalized remedy that deters all future
unlawful activity against all persons cannot satisfy the re-
mediation requirement, even though it deters (among other
things) repetition of this particular unlawful activity against
these particular plaintiffs.
Thus, relief against prospective harm is traditionally af-
forded by way of an injunction, the scope of which is limited
by the scope of the threatened injury. Lewis v. Casey, 518
U. S. 343, 357–360 (1996); Lyons, 461 U. S, at 105–107, and
n. 7. In seeking to overturn that tradition by giving an indi-
onment was that, unlike imprisonment for civil contempt, it would not
condition the father’s release upon payment. The Court then continued:
“The prospect that prosecution will, at least in the future”—i. e., upon
completion of the imprisonment—“result in payment of support can, at
best, be termed only speculative.” Linda R. S., 410 U. S., at 618.

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
205 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
vidual plaintiff the power to invoke a public remedy, Con-
gress has done precisely what we have said it cannot do:
convert an “undifferentiated public interest” into an “indi-
vidual right” vindicable in the courts. Lujan, supra, at 577;
Steel Co., 523 U. S., at 106. The sort of scattershot redress
approved today makes nonsense of our statement in Schles-
inger v. Reservists Comm. to Stop the War, 418 U. S. 208,
222 (1974), that the requirement of injury in fact “insures
the framing of relief no broader than required by the precise
facts.” A claim of particularized future injury has today
been made the vehicle for pursuing generalized penalties for
past violations, and a threshold showing of injury in fact has
become a lever that will move the world.
B
As I have just discussed, it is my view that a plaintiff ’s
desire to benefit from the deterrent effect of a public penalty
for past conduct can never suffice to establish a case or con-
troversy of the sort known to our law. Such deterrent effect
is, so to speak, “speculative as a matter of law.” Even if
that were not so, however, the deterrent effect in the present
case would surely be speculative as a matter of fact.
The Court recognizes, of course, that to satisfy Article III,
it must be “likely,” as opposed to “merely speculative,” that
a favorable decision will redress plaintiffs’ injury, Lujan,
supra, at 561. See ante, at 180–181. Further, the Court
recognizes that not all deterrent effects of all civil penalties
will meet this standard—though it declines to “explore the
outer limits” of adequate deterrence, ante, at 187. It con-
cludes, however, that in the present case “the civil penalties
sought by FOE carried with them a deterrent effect” that
satisfied the “likely [rather than] speculative” standard.
Ibid. There is little in the Court’s opinion to explain why it
believes this is so.
The Court cites the District Court’s conclusion that the
penalties imposed, along with anticipated fee awards, pro-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
206 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
vided “adequate deterrence.” Ante, at 178, 187; 956 F.
Supp., at 611. There is absolutely no reason to believe, how-
ever, that this meant “deterrence adequate to prevent an in-
jury to these plaintiffs that would otherwise occur.” The
statute does not even mention deterrence in general (much
less deterrence of future harm to the particular plaintiff) as
one of the elements that the court should consider in fixing
the amount of the penalty. (That element can come in, if at
all, under the last, residual category of “such other matters
as justice may require.” 33 U. S. C. § 1319(d).) The statute
does require the court to consider “the seriousness of the
violation or violations, the economic benefit (if any) resulting
from the violation, any history of such violations, any good-
faith efforts to comply with the applicable requirements,
[and] the economic impact of the penalty on the violator . . . .”
Ibid.; see 956 F. Supp., at 601. The District Court meticu-
lously discussed, in subsections (a) through (e) of the portion
of its opinion entitled “Civil Penalty,” each one of those spec-
ified factors, and then—under subsection (f) entitled “Other
Matters As Justice May Require,” it discussed “1. Laidlaw’s
Failure to Avail Itself of the Reopener Clause,” “2. Recent
Compliance History,” and “3. The Ever-Changing Mercury
Limit.” There is no mention whatever—in this portion of
the opinion or anywhere else—of the degree of deterrence
necessary to prevent future harm to these particular plain-
tiffs. Indeed, neither the District Court’s final opinion
(which contains the “adequate deterrence” statement) nor
its earlier opinion dealing with the preliminary question
whether South Carolina’s previous lawsuit against Laidlaw
constituted “diligent prosecution” that would bar citizen suit,
see 33 U. S. C. § 1365(b)(1)(B), displayed any awareness that
deterrence of future injury to the plaintiffs was necessary
to support standing.
The District Court’s earlier opinion did, however, quote
with approval the passage from a District Court case which
began: “ ‘Civil penalties seek to deter pollution by discourag-

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
207 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
ing future violations. To serve this function, the amount of
the civil penalty must be high enough to insure that polluters
cannot simply absorb the penalty as a cost of doing busi-
ness.’ ” App. 122, quoting PIRG v. Powell Duffryn Termi-
nals, Inc., 720 F. Supp. 1158, 1166 (NJ 1989). When the Dis-
trict Court concluded the “Civil Penalty” section of its
opinion with the statement that “[t]aken together, this court
believes the above penalty, potential fee awards, and Laid-
law’s own direct and indirect litigation expenses provide ade-
quate deterrence under the circumstances of this case,” 956
F. Supp., at 611, it was obviously harking back to this general
statement of what the statutorily prescribed factors (and the
“as justice may require” factors, which in this case did not
include particularized or even generalized deterrence) were
designed to achieve. It meant no more than that the court
believed the civil penalty it had prescribed met the statu-
tory standards.
The Court points out that we have previously said “ ‘all
civil penalties have some deterrent effect,’ ” ante, at 185
(quoting Hudson v. United States, 522 U. S. 93, 102 (1997)).
That is unquestionably true: As a general matter, polluters
as a class are deterred from violating discharge limits by the
availability of civil penalties. However, none of the cases
the Court cites focused on the deterrent effect of a single
imposition of penalties on a particular lawbreaker. Even
less did they focus on the question whether that particular-
ized deterrent effect (if any) was enough to redress the in-
jury of a citizen plaintiff in the sense required by Article III.
They all involved penalties pursued by the government, not
by citizens. See id., at 96; Department of Revenue of Mont.
v. Kurth Ranch, 511 U. S. 767, 773 (1994); Tull v. United
States, 481 U. S. 412, 414 (1987).
If the Court had undertaken the necessary inquiry into
whether significant deterrence of the plaintiffs’ feared injury
was “likely,” it would have had to reason something like this:
Strictly speaking, no polluter is deterred by a penalty for

528US1 Unit: $U17 [06-15-01 20:45:42] PAGES PGT: OPIN
208 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
past pollution; he is deterred by the fear of a penalty for
future pollution. That fear will be virtually nonexistent if
the prospective polluter knows that all emissions violators
are given a free pass; it will be substantial under an emis-
sions program such as the federal scheme here, which is reg-
ularly and notoriously enforced; it will be even higher when
a prospective polluter subject to such a regularly enforced
program has, as here, been the object of public charges of
pollution and a suit for injunction; and it will surely be near
the top of the graph when, as here, the prospective polluter
has already been subjected to state penalties for the past
pollution. The deterrence on which the plaintiffs must rely
for standing in the present case is the marginal increase in
Laidlaw’s fear of future penalties that will be achieved by
adding federal penalties for Laidlaw’s past conduct.
I cannot say for certain that this marginal increase is zero;
but I can say for certain that it is entirely speculative
whether it will make the difference between these plaintiffs’
suffering injury in the future and these plaintiffs’ going un-
harmed. In fact, the assertion that it will “likely” do so is
entirely farfetched. The speculativeness of that result is
much greater than the speculativeness we found excessive in
Simon v. Eastern Ky. Welfare Rights Organization, 426
U. S. 26, 43 (1976), where we held that denying § 501(c)(3)
charitable-deduction tax status to hospitals that refused to
treat indigents was not sufficiently likely to assure future
treatment of the indigent plaintiffs to support standing.
And it is much greater than the speculativeness we found
excessive in Linda R. S. v. Richard D., discussed supra, at
203–204, where we said that “[t]he prospect that prosecution
[for nonsupport] will . . . result in payment of support can,
at best, be termed only speculative,” 410 U. S., at 618.
In sum, if this case is, as the Court suggests, within the
central core of “deterrence” standing, it is impossible to
imagine what the “outer limits” could possibly be. The
Court’s expressed reluctance to define those “outer limits”

528US1 Unit: $U17 [06-15-01 20:45:43] PAGES PGT: OPIN
209 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
serves only to disguise the fact that it has promulgated a
revolutionary new doctrine of standing that will permit the
entire body of public civil penalties to be handed over to
enforcement by private interests.
C
Article II of the Constitution commits it to the President
to “take Care that the Laws be faithfully executed,” Art. II,
§ 3, and provides specific methods by which all persons ex-
ercising significant executive power are to be appointed,
Art. II, § 2. As Justice Kennedy’s concurrence correctly
observes, the question of the conformity of this legislation
with Article II has not been argued—and I, like the Court,
do not address it. But Article III, no less than Article II,
has consequences for the structure of our government, see
Schlesinger, 418 U. S., at 222, and it is worth noting the
changes in that structure which today’s decision allows.
By permitting citizens to pursue civil penalties payable to
the Federal Treasury, the Act does not provide a mechanism
for individual relief in any traditional sense, but turns over
to private citizens the function of enforcing the law. A
Clean Water Act plaintiff pursuing civil penalties acts as a
self-appointed mini-EPA. Where, as is often the case, the
plaintiff is a national association, it has significant discretion
in choosing enforcement targets. Once the association is
aware of a reported violation, it need not look long for an
injured member, at least under the theory of injury the
Court applies today. See supra, at 198–201. And once the
target is chosen, the suit goes forward without meaningful
public control.2 The availability of civil penalties vastly dis-
2 The Court points out that the Government is allowed to intervene in a
citizen suit, see ante, at 188, n. 4; 33 U. S. C. § 1365(c)(2), but this power
to “bring the Government’s views to the attention of the court,” ante, at
188, n. 4, is meager substitute for the power to decide whether prosecution
will occur. Indeed, according the Chief Executive of the United States
the ability to intervene does no more than place him on a par with John

528US1 Unit: $U17 [06-15-01 20:45:43] PAGES PGT: OPIN
210 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
proportionate to the individual injury gives citizen plaintiffs
massive bargaining power—which is often used to achieve
settlements requiring the defendant to support environmen-
tal projects of the plaintiffs’ choosing. See Greve, The Pri-
vate Enforcement of Environmental Law, 65 Tulane L. Rev.
339, 355–359 (1990). Thus is a public fine diverted to a pri-
vate interest.
To be sure, the EPA may foreclose the citizen suit by itself
bringing suit. 33 U. S. C. § 1365(b)(1)(B). This allows pub-
lic authorities to avoid private enforcement only by accepting
private direction as to when enforcement should be under-
taken—which is no less constitutionally bizarre. Elected of-
ficials are entirely deprived of their discretion to decide that
a given violation should not be the object of suit at all, or
that the enforcement decision should be postponed.3 See
§ 1365(b)(1)(A) (providing that citizen plaintiff need only wait
60 days after giving notice of the violation to the government
before proceeding with action). This is the predictable and
inevitable consequence of the Court’s allowing the use of
public remedies for private wrongs.
III
Finally, I offer a few comments regarding the Court’s dis-
cussion of whether FOE’s claims became moot by reason of
Laidlaw’s substantial compliance with the permit limits.
I do not disagree with the conclusion that the Court reaches.
Assuming that the plaintiffs had standing to pursue civil pen-
alties in the first instance (which they did not), their claim
Q. Public, who can intervene—whether the Government likes it or not—
when the United States files suit. § 1365(b)(1)(B).
3 The Court observes that “the Federal Executive Branch does not share
the dissent’s view that such suits dissipate its authority to enforce the
law,” since it has “endorsed this citizen suit from the outset.” Ante, at
188, n. 4. Of course, in doubtful cases a long and uninterrupted history
of Presidential acquiescence and approval can shed light upon the constitu-
tional understanding. What we have here—acquiescence and approval by
a single administration—does not deserve passing mention.

528US1 Unit: $U17 [06-15-01 20:45:43] PAGES PGT: OPIN
211 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
might well not have been mooted by Laidlaw’s voluntary
compliance with the permit, and leaving this fact-intensive
question open for consideration on remand, as the Court
does, ante, at 193–194, seems sensible.4 In reaching this dis-
position, however, the Court engages in a troubling discus-
sion of the purported distinctions between the doctrines of
standing and mootness. I am frankly puzzled as to why this
discussion appears at all. Laidlaw’s claimed compliance is
squarely within the bounds of our “voluntary cessation” doc-
trine, which is the basis for the remand. Ante, at 193. 5
4 In addition to the compliance and plant-closure issues, there also re-
mains open on remand the question whether the current suit was fore-
closed because the earlier suit by the State was “diligently prosecuted.”
See 33 U. S. C. § 1365(b)(1)(B). Nothing in the Court’s opinion disposes of
the issue. The opinion notes the District Court’s finding that Laidlaw
itself played a significant role in facilitating the State’s action. Ante, at
178, n. 1, 186, n. 2. But there is no incompatibility whatever between
a defendant’s facilitation of suit and the State’s diligent prosecution—as
prosecutions of felons who confess their crimes and turn themselves in
regularly demonstrate. Laidlaw was entirely within its rights to prefer
state suit to this private enforcement action; and if it had such a prefer-
ence it would have been prudent—given that a State must act within 60
days of receiving notice of a citizen suit, see § 1365(b)(1)(A), and given the
number of cases state agencies handle—for Laidlaw to make sure its case
did not fall through the cracks. South Carolina’s interest in the action
was not a feigned last minute contrivance. It had worked with Laidlaw
in resolving the problem for many years, and had previously undertaken
an administrative enforcement action resulting in a consent order. 890
F. Supp. 470, 476 (SC 1995). South Carolina has filed an amicus brief
arguing that allowing citizen suits to proceed despite ongoing state en-
forcement efforts “will provide citizens and federal judges the opportunity
to relitigate and second-guess the enforcement and permitting actions of
South Carolina and other States.” Brief for South Carolina as Amicus
Curiae 6.
5 Unlike Justice Stevens’ concurrence, the opinion for the Court ap-
pears to recognize that a claim for civil penalties is moot when it is clear
that no future injury to the plaintiff at the hands of the defendant can
occur. The concurrence suggests that civil penalties, like traditional dam-
ages remedies, cannot be mooted by absence of threatened injury. The
analogy is inapt. Traditional money damages are payable to compensate

528US1 Unit: $U17 [06-15-01 20:45:43] PAGES PGT: OPIN
212 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
There is no reason to engage in an interesting academic ex-
cursus upon the differences between mootness and standing
in order to invoke this obviously applicable rule.6
Because the discussion is not essential—indeed, not even
relevant—to the Court’s decision, it is of limited significance.
Nonetheless, I am troubled by the Court’s too-hasty retreat
from our characterization of mootness as “the doctrine of
standing set in a time frame.” Arizonans for Official Eng-
lish v. Arizona, 520 U. S. 43, 68, n. 22 (1997). We have re-
peatedly recognized that what is required for litigation to
continue is essentially identical to what is required for litiga-
tion to begin: There must be a justiciable case or controversy
as required by Article III. “Simply stated, a case is moot
when the issues presented are no longer ‘live’ or the parties
lack a legally cognizable interest in the outcome.” Powell
v. McCormack, 395 U. S. 486, 496 (1969). A court may not
for the harm of past conduct, which subsists whether future harm is
threatened or not; civil penalties are privately assessable (according to the
Court) to deter threatened future harm to the plaintiff. Where there is
no threat to the plaintiff, he has no claim to deterrence. The proposition
that impossibility of future violation does not moot the case holds true, of
course, for civil-penalty suits by the government, which do not rest upon
the theory that some particular future harm is being prevented.
6 The Court attempts to frame its exposition as a corrective to the
Fourth Circuit, which it claims “confused mootness with standing.” Ante,
at 189. The Fourth Circuit’s conclusion of nonjusticiability rested upon
the belief (entirely correct, in my view) that the only remedy being pur-
sued on appeal, civil penalties, would not redress FOE’s claimed injury.
149 F. 3d 303, 306 (1998). While this might be characterized as a conclu-
sion that FOE had no standing to pursue civil penalties from the outset,
it can also be characterized, as it was by the Fourth Circuit, as a conclusion
that, when FOE declined to appeal denial of the declaratory judgment and
injunction, and appealed only the inadequacy of the civil penalties (which
it had no standing to pursue) the case as a whole became moot. Given
the Court’s erroneous conclusion that civil penalties can redress private
injury, it of course rejects both formulations—but neither of them necessi-
tates the Court’s academic discourse comparing the mootness and stand-
ing doctrines.

528US1 Unit: $U17 [06-15-01 20:45:43] PAGES PGT: OPIN
213 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
proceed to hear an action if, subsequent to its initiation, the
dispute loses “its character as a present, live controversy of
the kind that must exist if [the court is] to avoid advisory
opinions on abstract propositions of law.” Hall v. Beals, 396
U. S. 45, 48 (1969) (per curiam). See also Preiser v. New-
kirk, 422 U. S. 395, 401 (1975); Steffel v. Thompson, 415 U. S.
452, 459, n. 10 (1974). Because the requirement of a continu-
ing case or controversy derives from the Constitution, Liner
v. Jafco, Inc., 375 U. S. 301, 306, n. 3 (1964), it may not be
ignored when inconvenient, United States v. Alaska S. S. Co.,
253 U. S. 113, 116 (1920) (moot question cannot be decided,
“[h]owever convenient it might be”), or, as the Court sug-
gests, to save “sunk costs,” compare ante, at 192, with Lewis
v. Continental Bank Corp., 494 U. S. 472, 480 (1990) (“[R]ea-
sonable caution is needed to be sure that mooted litigation is
not pressed forward . . . solely in order to obtain reimburse-
ment of sunk costs”).
It is true that mootness has some added wrinkles that
standing lacks. One is the “voluntary cessation” doctrine to
which the Court refers. Ante, at 189. But it is inaccurate
to regard this as a reduction of the basic requirement for
standing that obtained at the beginning of the suit. A genu-
ine controversy must exist at both stages. And just as the
initial suit could be brought (by way of suit for declaratory
judgment) before the defendant actually violated the plain-
tiff ’s alleged rights, so also the initial suit can be continued
even though the defendant has stopped violating the plain-
tiff ’s alleged rights. The “voluntary cessation” doctrine is
nothing more than an evidentiary presumption that the con-
troversy reflected by the violation of alleged rights continues
to exist. Steel Co., 523 U. S., at 109. Similarly, the fact that
we do not find cases moot when the challenged conduct is
“capable of repetition, yet evading review” does not demon-
strate that the requirements for mootness and for standing
differ. “Where the conduct has ceased for the time being

528US1 Unit: $U17 [06-15-01 20:45:43] PAGES PGT: OPIN
214 FRIENDS OF EARTH, INC. v. LAIDLAW ENVI-
RONMENTAL SERVICES (TOC), INC.
Scalia, J., dissenting
but there is a demonstrated probability that it will recur, a
real-life controversy between parties with a personal stake
in the outcome continues to exist.” Honig v. Doe, 484 U. S.
305, 341 (1988) (Scalia, J., dissenting) (emphasis deleted).
Part of the confusion in the Court’s discussion is engen-
dered by the fact that it compares standing, on the one hand,
with mootness based on voluntary cessation, on the other
hand. Ante, at 190. The required showing that it is “abso-
lutely clear” that the conduct “could not reasonably be ex-
pected to recur” is not the threshold showing required for
mootness, but the heightened showing required in a particu-
lar category of cases where we have sensibly concluded that
there is reason to be skeptical that cessation of violation
means cessation of live controversy. For claims of mootness
based on changes in circumstances other than voluntary ces-
sation, the showing we have required is less taxing, and the
inquiry is indeed properly characterized as one of “ ‘standing
set in a time frame.’ ” See Arizonans, supra, at 67, 68, n. 22
(case mooted where plaintiff ’s change in jobs deprived case
of “still vital claim for prospective relief ”); Spencer v.
Kemna, 523 U. S. 1, 7 (1998) (case mooted by petitioner’s
completion of his sentence, since “throughout the litigation,
the plaintiff must have suffered, or be threatened with, an
actual injury traceable to the defendant and likely to be re-
dressed by a favorable judicial decision” (internal quotation
marks omitted)); Lewis, supra, at 478–480 (case against State
mooted by change in federal law that eliminated parties’
“personal stake” in the outcome).
In sum, while the Court may be correct that the parallel
between standing and mootness is imperfect due to realistic
evidentiary presumptions that are by their nature applicable
only in the mootness context, this does not change the under-
lying principle that “ ‘[t]he requisite personal interest that
must exist at the commencement of the litigation . . . must
continue throughout its existence . . . .’ ” Arizonans, supra,

528US1 Unit: $U17 [06-15-01 20:45:43] PAGES PGT: OPIN
215 Cite as: 528 U. S. 167 (2000)
Scalia, J., dissenting
at 68, n. 22 (quoting United States Parole Comm’n v.
Geraghty, 445 U. S. 388, 397 (1980)).
* * *
By uncritically accepting vague claims of injury, the Court
has turned the Article III requirement of injury in fact into
a “mere pleading requirement,” Lujan, 504 U. S., at 561;
and by approving the novel theory that public penalties can
redress anticipated private wrongs, it has come close to
“mak[ing] the redressability requirement vanish,” Steel Co.,
supra, at 107. The undesirable and unconstitutional conse-
quence of today’s decision is to place the immense power of
suing to enforce the public laws in private hands. I respect-
fully dissent.