CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE FOURTH CIRCUIT.
Marshall, J., delivered the opinion of the Court, in which Rehnquist, C. J., and Brennan, White, and Blackmun, JJ., joined, and in Parts I and II of which Stevens, O'connor, and Scalia, JJ., joined. Scalia, J., filed an opinion concurring in part and concurring in the judgment, in which Stevens and O'connor, JJ., joined, post, p. 67.
JUSTICE MARSHALL delivered the opinion of the Court.
In this case, we must decide whether § 505(a) of the Clean Water Act, also known as the Federal Water Pollution Control Act, 33 U. S. C. § 1365(a), confers federal jurisdiction over citizen suits for wholly past violations.
The Clean Water Act (Act), 86 Stat. 816, 33 U. S. C. § 1251 et seq. (1982 ed. and Supp. III), was enacted in 1972 "to restore and maintain the chemical, physical, and biological integrity of the Nation's waters." § 1251(a). In order to achieve these goals, § 301(a) of the Act makes unlawful the discharge of any pollutant into navigable waters except as authorized by specified sections of the Act. 33 U. S. C. § 1311(a).
One of these specified sections is § 402, which establishes the National Pollutant Discharge Elimination System (NPDES). 33 U. S. C. § 1342. Pursuant to § 402(a), the Administrator of the Environmental Protection Agency (EPA) may issue permits authorizing the discharge of pollutants in accordance with specified conditions. § 1342(a). Pursuant to § 402(b), each State may establish and administer its own permit program if the program conforms to federal guidelines and is approved by the Administrator. § 1342(b). The Act calls for the Administrator to suspend the issuance of federal permits as to waters subject to an approved state program. § 1342(c)(1).
The holder of a federal NPDES permit is subject to enforcement action by the Administrator for failure to comply
with the conditions of the permit. The Administrator's enforcement arsenal includes administrative, civil, and criminal sanctions. § 1319. The holder of a state NPDES permit is subject to both federal and state enforcement action for failure to comply. §§ 1319, 1342(b)(7). In the absence of federal or state enforcement, private citizens may commence civil actions against any person "alleged to be in violation of" the conditions of either a federal or state NPDES permit. § 1365(a)(1). If the citizen prevails in such an action, the court may order injunctive relief and/or impose civil penalties payable to the United States Treasury. § 1365(a).
The Commonwealth of Virginia established a federally approved state NPDES program administered by the Virginia State Water Control Board (Board). Va. Code § 62.1-44.2 et seq. (1950). In 1974, the Board issued a NPDES permit to ITT-Gwaltney authorizing the discharge of seven pollutants from the company's meatpacking plant on the Pagan River in Smithfield, Virginia. The permit, which was reissued in 1979 and modified in 1980, established effluent limitations, monitoring requirements, and other conditions of discharge. In 1981, petitioner Gwaltney of Smithfield acquired the assets of ITT-Gwaltney and assumed obligations under the permit.
Between 1981 and 1984, petitioner repeatedly violated the conditions of the permit by exceeding effluent limitations on five of the seven pollutants covered. These violations are chronicled in the Discharge Monitoring Reports that the permit required petitioner to maintain. See 9 Record, Exh. 10. The most substantial of the violations concerned the pollutants fecal coliform, chlorine, and total Kjeldahl nitrogen (TKN). Between October 27, 1981, and August 30, 1984, petitioner violated its TKN limitation 87 times, its chlorine limitation 34 times, and its fecal coliform limitation 31 times. 9 Record, Stipulation, p. 3. Petitioner installed new equipment to improve its chlorination system in March 1982, and its last reported chlorine violation occurred in October 1982.
the time of suit. Gwaltney urged the District Court to adopt the analysis of the Fifth Circuit in Hamker v. Diamond Shamrock Chemical Co., 756 F.2d 392 (1985), which held that "a complaint brought under [§ 505] must allege a violation occurring at the time the complaint is filed." Id., at 395. Gwaltney contended that because its last recorded violation occurred several weeks before respondents filed their complaint, the District Court lacked subject-matter jurisdiction over respondents' action. See 4 Record, Doc. No. 44.
The District Court rejected Gwaltney's argument, concluding that § 505 authorizes citizens to bring enforcement actions on the basis of wholly past violations. The District Court found that "[t]he words 'to be in violation' may reasonably be read as comprehending unlawful conduct that occurred solely prior to the filing of the lawsuit as well as unlawful conduct that continues into the present." 611 F. Supp. 1542, 1547 (ED Va. 1985). In the District Court's view, this construction of the statutory language was supported by the legislative history and the underlying policy goals of the Act. Id., at 1550. The District Court held in the alternative that respondents satisfied the jurisdictional requirements of § 505 because their complaint alleged in good faith that Gwaltney was continuing to violate its permit at the time the suit was filed. Id., at 1549, n. 8.
The Court of Appeals affirmed, expressly rejecting the Fifth Circuit's approach in Hamker and holding that § 505 "can be read to comprehend unlawful conduct that occurred only prior to the filing of a lawsuit as well as unlawful conduct that continues into the present." 791 F.2d 304, 309 (CA4 1986). The Court of Appeals concluded that its reading of § 505 was consistent with the Act's structure, legislative history, and purpose. Although it observed that "[a] very sound argument can be made that [respondents'] allegations of continuing violations were made in good faith," the Court of Appeals declined to rule on the District Court's alternative holding, finding it unnecessary to the disposition of the case. Id., at 308, n. 9.
Subsequent to the issuance of the Fourth Circuit's opinion, the First Circuit also had occasion to construe § 505. It took a position different from that of either the Fourth or the Fifth Circuit, holding that jurisdiction lies under § 505 when "the citizen-plaintiff fairly alleges a continuing likelihood that the defendant, if not enjoined, will again proceed to violate the Act." Pawtuxet Cove Marina, Inc. v. Ciba-Geigy Corp., 807 F.2d 1089, 1094 (1986). The First Circuit's approach precludes suit based on wholly past violations, but permits suit when there is a pattern of intermittent violations, even if there is no violation at the moment suit is filed. We granted certiorari to resolve this three-way conflict in the Circuits. 479 U.S. 1029 (1987). We now vacate the Fourth Circuit's opinion and remand the case.
It is well settled that "the starting point for interpreting a statute is the language of the statute itself." Consumer Product Safety Comm'n v. GTE Sylvania, Inc., 447 U.S. 102, 108 (1980). The Court of Appeals concluded that the "to be in violation" language of § 505 is ambiguous, whereas petitioner asserts that it plainly precludes the construction
adopted below. We must agree with the Court of Appeals that § 505 is not a provision in which Congress' limpid prose puts an end to all dispute. But to acknowledge ambiguity is not to conclude that all interpretations are equally plausible. The most natural reading of "to be in violation" is a requirement that citizen-plaintiffs allege a state of either continuous or intermittent violation -- that is, a reasonable likelihood that a past polluter will continue to pollute in the future. Congress could have phrased its requirement in language that looked to the past ("to have violated"), but it did not choose this readily available option.
Respondents urge that the choice of the phrase "to be in violation," rather than phrasing more clearly directed to the past, is a "careless accident," the result of a "debatable lapse of syntactical precision." Brief for Respondents 8. But the prospective orientation of that phrase could not have escaped Congress' attention. Congress used identical language in the citizen suit provisions of several other environmental statutes that authorize only prospective relief. See, e. g., Clean Air Act, 42 U. S. C. § 7604; Resource Conservation and Recovery Act of 1976, 42 U. S. C. § 6972 (1982 ed. and Supp. III); Toxic Substances Control Act, 15 U. S. C. § 2619 (1982 ed. and Supp. IV). Moreover, Congress ...