with whom Justice Marshall and Justice Stevens join, dissenting.
Nine years ago, in Illinois v. Milwaukee, 406 U. S. 91 (1972), this Court unanimously determined that Illinois could bring a federal common-law action against the city of *333Milwaukee, three other Wisconsin cities, and two sewerage commissions. At that time, Illinois alleged that the discharge of raw and untreated sewage by these Wisconsin entities into Lake Michigan created a public nuisance for the citizens of Illinois. The Court remitted the parties to an appropriate federal district court, “whose powers are adequate to resolve the issues.” Id., at 108.
Illinois promptly initiated the present litigation,1 and pursued it through more than three years of pretrial discovery, a 6-month trial that entailed hundreds of exhibits and scores of witnesses, extensive factual findings by the District Court, App. F to Pet. for Cert., and an exhaustive review of the evidence by the Court of Appeals. 599 F. 2d 151, 167-177 (CA7 1979). Today, the Court decides that this 9-year judicial exercise has been just a meaningless charade, cf. Hughes Tool Co. v. Trans World Airlines, Inc., 409 U. S. 363, 389, 390 (1973) (dissenting opinion), inasmuch as, it says, the federal common-law remedy approved in Illinois v. Milwaukee was implicitly extinguished by Congress just six months after the 1972 decision. Because I believe that Congress intended no such extinction, and surely did not contemplate the result reached by the Court today, I respectfully dissent.
I
The Courtis analysis of federal common-law displacement rests, I am convinced, on a faulty assumption. In contrasting congressional displacement of the common law with federal pre-emption of state law,2 the Court assumes that as *334soon as Congress “addresses a question previously governed” by federal common law, “the need for such an unusual exercise of lawmaking by federal courts disappears.” Ante, at 314. This “automatic displacement” approach is inadequate in two respects. It fails to reflect the unique role federal common law plays in resolving disputes between one State and the citizens or government of another. In addition, it ignores this Court’s frequent recognition that federal common law may complement congressional action in the fulfillment of federal policies.
It is well settled that a body of federal common law has survived the decision in Erie R. Co. v. Tompkins, 304 U. S. 64 (1938). Erie made clear that federal courts, as courts of limited jurisdiction, lack general power to formulate and impose their own rules of decision. Id., at 78. The Court, however, did not there upset, nor has it since disturbed, a deeply rooted, more specialized federal common law that has arisen to effectuate federal interests embodied either in the Constitution or an Act of Congress.3 Chief among the fed*335eral interests served by this common law are the resolution of interstate disputes and the implementation of national statutory or regulatory policies.
Both before and after Erie, the Court has fashioned federal law where the interstate nature of a controversy renders inappropriate the law of either State. See, e. g., Nebraska v. Wyoming, 325 U. S. 589 (1945); Hinderlider v. La Plata Co., 304 U. S. 92, 110 (1938); Kansas v. Colorado, 206 U. S. 46, 95, 97-98 (1907) (apportioning waters of interstate stream). See also Cissna v. Tennessee, 246 U. S. 289, 296 (1918); Howard v. Ingersoll, 13 How. 381 (1852) (resolving interstate boundary conflict). When such disputes arise, it is clear under our federal system that laws of one State cannot impose upon the sovereign rights and interests of another. The Constitution, by Art. III, § 2, explicitly extends the judicial power of the United States to controversies between a State and another State or its citizens, and this Court, in equitably resolving such disputes, has developed a body of “what may not improperly be called interstate common law.” Kansas v. Colorado, 206 U. S., at 98.
Long before the 1972 decision in Illinois v. Milwaukee, federal common law enunicated by this Court assured each State the right to be free from unreasonable interference with its natural environment and resources when the interference stems from another State or its citizens. Georgia v. Tennessee Copper Co., 206 U. S. 230, 237-239 (1907); Missouri v. Illinois, 200 U. S. 496, 520, 526 (1906). See New Jersey v. City of New York, 283 U. S. 473 (1931); New York v. New Jersey, 256 U. S. 296 (1921). The right to such federal protection is a consequence of each State's entry into the Union and its commitment to the Constitution. In the words of Justice Holmes, speaking for the Court:
“When the States by their union made the forcible *336abatement of outside nuisances impossible to each, they did not thereby agree to submit to whatever might be done. They did not renounce the possibility of making reasonable demands on the ground of their still remaining gwcm-sovereign interests; and the alternative to force is a suit in this court.” Georgia v. Tennessee Copper Co., 206 U. S., at 237.
This Court also has applied federal common law where federally created substantive rights and obligations are at stake. Thus, the Court has been called upon to pronounce common law that will fill the interstices of a pervasively federal framework, or avoid subjecting relevant federal interests to the inconsistencies in the laws of several States. Textile Workers v. Lincoln Mills, 353 U. S. 448, 456-457 (1957); United States v. Standard Oil Co., 332 U. S. 301, 305 (1947); Clearfield Trust Co. v. United States, 318 U. S. 363, 366-367 (1943); D’Oench, Duhme & Co. v. Federal Deposit Ins. Corp., 315 U. S. 447 (1942). If the federal interest is sufficiently strong, federal common law may be drawn upon in settling disputes even though the statute or Constitution alone provides no precise answer to the question posed. See, e. g., Textile Workers v. Lincoln Mills, 353 U. S., at 458; Clearfield Trust Co. v. United States, 318 U. S., at 368-370. See generally United States v. Little Lake Misere Land Co., 412 U. S. 580, 593 (1973) (“the inevitable incompleteness presented by all legislation means that interstitial federal lawmaking is a basic responsibility of the federal courts”).
Each of these sources of federal common law was recognized in Illinois v. Milwaukee. The Court there concluded that the common law of interstate nuisance supplied the requisite federal-question jurisdiction to bring an action in District Court. In so deciding, the Court reasoned that it was appropriate for federal courts to fashion federal common law “where there is an overriding federal interest in the need for a uniform rule of decision or where the controversy *337touches basic interests of federalism.” 406 U. S., at 105, n. 6. The Court relied heavily upon interstate air pollution and water allocation cases where the complaining party was a State invoking the Court’s original jurisdiction. Id., at 1CMH06. In addition, it recounted the history of federal interstate water quality legislation and suggested that the abiding federal interest in the purity of interstate waters justified application of federal common law. Id., at 101-103. Significantly, the Court found no barrier to federal common law despite the number of federal statutes and regulations that already provided remedies to abate pollution in interstate waters. Id., at 103.
Thus, quite contrary to the statements and intimations of the Court today, ante, at 323, 325, 327, n. 19, Illinois v. Milwaukee did not create the federal common law of nuisance. Well before this Court and Congress acted in 1972, there was ample recognition of and foundation for a federal common law of nuisance applicable to Illinois’ situation.4 Congress cannot be presumed to have been unaware of the relevant common-law history, any more than it can be deemed to have been oblivious to the decision in Illinois v. *338Milwaukee, announced six months prior to the passage of the Federal Water Pollution Control Act Amendments of 1972 (Act or Amendments), 86 Stat. 816. The central question is whether, given its presumed awareness, Congress, in passing these Amendments, intended to prevent recourse to the federal common law of nuisance.
The answer to this question, it seems to me, requires a more thorough exploration of congressional intent than is offered by the Court. Congress had “spoken to” the particular problem of interstate water pollution as far back as 1888,5 and in 1948 did so in a broad and systematic fashion with the enactment of the Water Pollution Control Act (also known as the Clean Water Act).6 In Illinois v. Milwaukee, the Court properly regarded such expressions of congressional intent as not an obstacle but an incentive to application of the federal common law. 406 U. S., at 102-103. The fact that Congress in 1972 once again addressed the complicated and difficult problem of purifying our Nation’s waters should not be taken as presumptive evidence, let alone conclusive proof, that Congress meant to foreclose pre-existing approaches to controlling interstate water pollution.7 Where the possi*339ble extinction of federal common law is at issue, a reviewing court is obligated to look not only to the magnitude of the legislative action but also with some care to the evidence of specific congressional intent.8
II
In my view, the language and structure of the Clean Water Act leave no doubt that Congress intended to preserve the federal common law of nuisance. Section 505 (e) of the Act reads:
“Nothing in this section shall restrict any right which any person (or class of persons) may have under any statute or common law to seek enforcement of any effluent standard or limitation or to seek any other relief (including relief against the Administrator or a State agency).” 33 U. S. C. § 1365 (e) (emphasis added).
The Act specifically defines “person” to include States, and thus embraces respondents Illinois and Michigan. § 502 (5), *34033 U. S. C. § 1362 (5). It preserves their right to bring an action against the governmental entities who are charged with enforcing the statute. Most important, as succinctly-stated by the Court of Appeals in this case: “There is nothing in the phrase 'any statute or common law’ that suggests that this provision is limited to state common law.” 599 F. 2d, at 163. To the best of my knowledge, every federal court that has considered the issue has concluded that, in enacting § 505 (e), Congress meant to preserve federal as well as state common law.9
Other sections of the Clean Water Act also support the conclusion that Congress in 1972 had no intention of extinguishing the federal common law of nuisance. Although the Act established a detailed and comprehensive regulatory system aimed at eliminating the discharge of pollutants into all navigable waters, it did not purport to impose a unitary enforcement structure for abating water pollution. In par*341ticular, Congress expressly provided that the effluent limitations promulgated under the Act do not preclude any State from establishing more stringent limitations. § 510, 33 U. S. C. § 1370. It also made clear that federal officers or agencies are not foreclosed from adopting or enforcing stricter pollution controls and standards than those required by the Act. § 511 (a), 33 U. S. C. § 1371 (a).
Thus, under the statutory scheme, any permit issued by the EPA or a qualifying state agency does not insulate a dis-charger from liability under other federal or state law.10 To the contrary, the permit granted pursuant to § 402 (k), 33 U. S. C. § 1342 (k), confers assurances with respect to certain specified sections of the Act, but the requirements under other provisions as well as separate legal obligations remain unaffected. See EPA v. State Water Resources Control Board, 426 U. S. 200, 205 (1976). Congress plainly anticipated that dischargers might be required to meet standards more stringent than the minimum effluent levels approved by the EPA. Those more stringent standards would necessarily be established by other statutes or by common law. Because the Act contemplates a shared authority between the Federal Government and the individual States, see, e. g., § 101 (b), 33 U. S. C. § 1251 (b) (1976 ed., Supp. Ill), it is entirely understandable that Congress thought it neither imperative nor desirable to insist upon an exclusive approach to the improvement of water quality.11
The Court offers three responses to this view of congressional intent. With regard to the language of § 505 (e), it attributes critical significance to the words “this section,” *342and concludes that Congress meant only to assure that the citizen-suit provision did not extinguish formerly available federal common-law actions. Ante, at 328-330. The Court thus reads § 505 (e) as though Congress had said that “ This section’ does not take away any pre-existing remedies, but the remainder of the statute does.” This is an extremely strained reading of the statutory language,12 and one that is at odds with the manifest intent of Congress to permit more stringent remedies under both federal and state law. See §§ 510, 511, 33 U. S. C. §§ 1370, 1371. If § 505 (e) is to be construed as the Court suggests, then it authorizes the abrogation of all pre-existing rights, both statutory and common law, in the area of water pollution control. The Court’s construction therefore, would render suspect, if not meaningless, the Act’s other provisions. Rather than interpreting § 505 (e) as a license to supplant all legal remedies outside the Act itself, I would construe the reference to “this section” as simply preventing pre-existing rights of action from being subjected to the procedural and jurisdictional limitations imposed by § 505 on persons who would sue under the Act.
The Court also relies on certain language contained in the legislative history of the 1972 Amendments. Ante, at 317-319. Based on the remarks of several of the Act’s proponents that this was the most comprehensive water pollution bill prepared to date, the Court finds a strong congressional suggestion that there is no room for improvement through the federal common law. But there is nothing talismanic about such generalized references. The fact that legislators may characterize their efforts as more “comprehensive” than prior legislation hardly prevents them from authorizing the continued existence of supplemental legal and equitable solutions to the broad and serious problem addressed.13 More*343over, the Court ignores express statements of legislative intent that contradict its position. The Senate Report accompanying the 1972 legislation explicitly describes the congressional intent informing § 505 (e):
“It should be noted, however, that the section would specifically preserve any rights or remedies under any other law. Thus, if damages could be shown, other remedies would remain available. Compliance with requirements under this Act would not be a defense to a common law action for pollution damages.” S. Rep. No. 92-414, p. 81 (1971), reprinted in 2 Legislative History of the Water Pollution Control Act Amendments of 1972 (Committee Print compiled for the Senate Committee on Public Works by the Library of Congress), Ser. No. 93-1, p. 1499 (1973) (Leg. Hist.).14
This deliberate preservation of all remedies previously available at common law makes no distinction between the common law of individual States and federal common law. Indeed, the legislative debates indicate that Congress was specifically aware of the presence of federal common law, and intended that it would survive passage of the 1972 Amendments. In one particularly revealing colloquy on the Senate floor, Senator Griffin noted the pendency of a suit challenging the dumping of iron ore pollutants into Lake *344Superior. 1 Leg. Hist. 191. See Reserve Mining Co. v. EPA, 514 F. 2d 492 (CA8 1975) (en banc). The Senator inquired whether the suit, which was based in part on the federal common law of nuisance,15 would be affected by passage of the 1972 Amendments. Senators Muskie16 and Hart each responded that the new legislation would not affect or hinder “the suit now pending against the Reserve Mining Co., under the Refuse Act of 1899 ...[,] the existing Federal Water Pollution Control Act or other law.” 1 Leg. Hist. 211 (Sen. Hart) (emphasis added).17
*345Finally, the Court attaches significance to the fact that the 1972 Amendments provided a more rigorous administrative mechanism for addressing interstate controversies. Ante, at 325-326. The Court evidently regards the provision of a new administrative abatement process as a type of jurisdictional requirement, for it criticizes Illinois’ failure to invoke the mechanism before seeking any form of judicial relief. Ante, at 326. Even if this were the case, the new notice and hearing procedure became available only two years after Illinois commenced this action. There is no suggestion that Illinois failed to pursue administrative abatement under the then-applicable federal statute. Indeed, it is undisputed that Illinois made prolonged and diligent efforts to secure administrative relief.18 Nonetheless, the Court in effect concludes that it is not enough to exhaust administrative remedies that existed at the time a common-law action was initiated; a complainant must also be prepared to pursue new and wholly unforeseen administrative avenues even as it seeks a final judgment in federal court. I am aware of no ease that adopts so harsh an approach to the pursuit of administrative remedies, and I see no basis for imposing such a requirement in this context.
Moreover, contrary to what the Court implies, Congress never intended that failure to participate in the § 402 administrative process would serve as a jurisdictional bar. Nothing in the language of § 402 suggests that a neighboring State’s participation in the permit-granting process is anything other than voluntary and optional.19 Indeed, the Con-*346ferenee Committee considering the 1977 amendments to the Act was presented with a proposal that would have made such participation a jurisdictional prerequisite.20 This proposal was not adopted by the Conference Committee, and among its opponents was the Department of Justice. In a letter sent to all conferees, the Department made clear its understanding that, absent such an amendment, the federal common law would continue to be relied upon in the national effort to control water pollution.21
*347The Justice Department’s position on the survival of federal common law is consistent with the stance taken by the EPA both in this litigation and throughout the period since the 1972 Amendments were enacted. The EPA in fact has relied upon the federal common law of nuisance in addition to the remedies available under the statute in seeking to protect water quality.22 As the agency charged with enforcing and implementing the Act, EPA’s interpretation of the scope and limits of that statute is entitled to considerable deference. See Udall v. Tallman, 380 U. S. 1, 16 (1965). Where, as here, the agency has publicly and consistently acted upon its interpretation, congressional silence is not without significance, particularly since this area has been a subject of frequent and intense legislative attention. And where, as here, the agency’s continued reliance on federal common law is firmly grounded in the language and structure of the statute, I fail to see how the Court can so lightly disregard its interpretation.
*348Ill
Assuming that Congress did preserve a federal common law of nuisance, and that respondents properly stated federal common-law claims for relief, there remains the question whether the particular common law applied here was reasonable. Because of its ruling, the Court does not explicitly address this question. Nonetheless, in its detailed review of respondents’ claims, the Court in effect concludes that the federal common law applied by the District Court and the Court of Appeals was defective. In particular, the Court asserts that federal courts may not exceed the statutory minimum approach sanctioned by Congress, see ante, at 323, and may not use federal power to impose a State’s more stringent pollution limitation standards upon out-of-state polluters. See ante, at 327-328. In contrast, I believe the courts below acted correctly in both respects.
As the Court of Appeals properly recognized, 599 F. 2d, at 164, the determination by Congress to preserve rights of action at federal common law did not grant federal courts the freedom to disregard the statutory and regulatory structure approved by Congress. We noted in Illinois v. Milwaukee that “the various federal environmental protection statutes will not necessarily mark the outer bounds of the federal common law, [but] they may provide useful guidelines in fashioning such rules of decision.” 406 U. S., at 103, n. 5. These guidelines, however, bear primarily on the problems of proof faced by the parties; they do not determine the exclusive source of the law to be applied.
In this instance, problems of proof arise under a familiar form of common-law action. A public nuisance involves unreasonable interference with a right common to the general public.23 Drawing on the Court’s decision in Georgia v. Ten*349nessee Copper Co., 206 U. S., at 238-239, the Court of Appeals concluded that nuisance is established at federal common law only if “the defendant is carrying on an activity that is causing an injury or significant threat of injury to some cognizable interest of the complainant.” 599 F. 2d, at 165. Whether a particular interference qualifies as unreasonable, whether the injury is sufficiently substantial to warrant injunctive relief, and what form that relief should take are questions to be decided on the basis of particular facts and circumstances.24 The judgments at times are difficult, but they do not require courts to perform functions beyond their traditional capacities or experience.25
When choosing the precise legal principles to apply, common-law courts draw upon relevant standards of conduct available in their communities. Where federal common law is concerned, “th[is] choice-of-law task is a federal task for federal courts.” United States v. Little Lake Misere Land Co., 412 U. S., at 592. At the same time, while federal law *350controls a particular question or problem, state law may furnish an appropriate measure of the content of this federal law. See, e. g., Board of Comm’rs v. United States, 308 U. S. 343, 349-352 (1939). See also Textile Workers v. Lincoln Mills, 353 U. S., at 457; Clearfield Trust Co. v. United States, 318 U. S., at 367. What the Court today characterizes as the inappropriate application of more stringent standards from Illinois state law in fact reflects a federal common-law court’s proper exercise of choice-of-law discretion.26
The Act sets forth certain effluent limitations. As did the Court of Appeals,27 a court applying federal common law in a given instance may well decline to impose effluent limitations more stringent than those required by Congress, because the complainant has failed to show that stricter standards will abate the nuisance or appreciably diminish the threat of injury. But it is a far different proposition to pronounce, as does the Court today, that federal courts “lack authority to impose more stringent effluent limitations under federal common law than those imposed” under the statutory scheme. Ante, at 320 (emphasis added). The authority of the federal courts in this area was firmly established by the decision in Illinois v. Milwaukee. In delineating the legitimate scope of the federal common law, the Court there expressly noted the relevance of state standards, adding that “a State with high water-quality standards may well ask that its strict standards be honored and that it not be compelled to lower itself to the more degrading standards of a neighbor.” (Emphasis added.) 406 U. S., at 107. The Act attributes comparable respect to the stricter effluent limita*351tion levels imposed by individual States. § 510, 33 U. S. C. § 1370. Since both the Court and Congress fully expected that neighboring States might differ in their approaches to the regulation of the discharge of pollutants into their navigable waters, it is odd, to say the least, that federal courts should now be deprived of the common-law power to effect a reconciliation of these differences.
The problem of controlling overflows is particularly amenable to application of this common-law authority. As the courts below found, see 599 F. 2d, at 167-168, the sewer systems operated by petitioners include some 239 bypass or overflow points from which raw sewage is. discharged directly into Lake Michigan or into rivers that flow into the lake. In a single month in 1976, discharge from 11 of the 239 discrete overflow points amounted to some 646 million gallons of untreated sewage. Ibid. The trial court determined that these untreated fecal wastes, containing billions of pathogenic bacteria and viruses, are periodically transported by prevailing currents into the Illinois waters of Lake Michigan. The court further found that the presence of these pathogens in Illinois waters poses a significant risk of injury to Illinois residents, threatening to contaminate drinking water supplies and infect swimmers.28
Pursuant to the Act, publicly owned treatment works then in existence must apply “secondary treatment as defined by the Administrator” as of July 1, 1977. §§ 301 (b)(1)(B), 304(d)(1), 33 U. S. C. §§1311 (b)(1)(B), 1314(d)(1).29 *352No provision of the Act explicitly addresses the discharge of raw sewage into public waters from overflow points. Indeed, Congress in 1977 expressed concern that combined sewer overflows were a significant source of untreated sewage polluting the Nation’s waters, and it commissioned a study of the problem with a view toward possible further legislation.30 While the Administrator has issued regulations that define secondary treatment in terms of certain minimum levels of effluent quality, he also has acknowledged that combined sewer overflows raise special concerns that must be resolved on a case-by-case basis.31 This record demonstrates that both Congress and the Administrator recognized the inadequacy of the statutory scheme. It surely does not show that these responsible parties intended no role for the federal common law.
The lower courts in this case carefully evaluated the regulatory systems developed by each State to deal with the overflow problem. It was determined that the standards promulgated under the Illinois regulatory scheme were more stringent than those developed by the Wisconsin agency or imposed on petitioners under the Wisconsin state-court judgment. See 599 F. 2d, at 171-173. The District Court’s order imposed standards that reflected the more rigorous approach adopted in Illinois to restore and protect Illinois *353waters.32 The Court of Appeals noted that Wisconsin had allowed petitioners more time in which to eliminate or “correct” the overflow problem, but that petitioners conceded the feasibility of complying with the District Court’s deadlines. Id., at 172, 177. In my view, the Court of Appeals acted responsibly and in a manner wholly consistent with the common-law jurisdiction envisioned by the Court in Illinois v. Milwaukee.
IV
There is one final disturbing aspect to the Court’s decision. By eliminating the federal common law of nuisance in this area, the Court in effect is encouraging recourse to state law wherever the federal statutory scheme is perceived to offer inadequate protection against pollution from outside the State, either in its enforcement standards or in the remedies afforded. This recourse is now inevitable under a statutory scheme that accords a significant role to state as well as federal law. But in the present context it is also unfortunate, since it undermines the Court’s prior conclusion that it is federal rather than state law that should govern the regulation of interstate water pollution. Illinois v. Milwaukee, 406 U. S., at 102. Instead of promoting a more uniform federal approach to the problem of alleviating interstate pollution, I fear that today’s decision will lead States to turn to their *354own courts for statutory or common-law assistance in filling the interstices of the federal statute. Rather than encourage such a prospect, I would adhere to the principles clearly enunciated in Illinois v. Milwaukee, and affirm the judgment of the Court of Appeals.
This Court’s decision was issued April 24, 1972. The complaint was filed in the United States District Court for the Northern District of Illinois on May 19, 1972.
I have no quarrel with the Court’s distinction between the issues of federalism at stake in assessing congressional pre-emption of state law and the separation-of-powers concerns that are implicated here. But there is more to this distinction than the Court suggests. In deciding whether federal law pre-empts state law, the Court must be sensitive to the *334potential frustration of national purposes if the States are permitted to control conduct that is the subject of federal regulation. San Diego Building Trades Council v. Garmon, 359 U. S. 236, 244 (1959). See Florida Lime & Avocado Growers, Inc. v. Paul, 373 U. S. 132, 142 (1963). For this reason, in pre-emption analysis the role of federal law is often determined on an “all or nothing” basis. On the other hand, where federal interests alone are at stake, participation by the federal courts is often desirable, and indeed necessary, if federal policies developed by Congress are to be fully effectuated. See, e. g., Miree v. DeKalb County, 433 U. S. 25, 35 (1977) (opinion concurring in judgment); United States v. Little Lake Misere Land Co., 412 U. S. 580, 592-593 (1973). The whole concept of interstitial federal lawmaking suggests a cooperative interaction between courts and Congress that is less attainable where federal-state questions are involved.
See generally Hill, The Law-Making Power of the Federal Courts: Constitutional Preemption, 67 Colum. L. Rev. 1024, 1026-1042 (1967); Friendly, In Praise of Erie — and of the New Federal Common Law, 39 N. Y. U. L. Rev. 383, 405-422 (1964). See also Leybold, Federal Com*335mon Law: Judicially Established Effluent Standards as a Remedy in Federal Nuisance Actions, 7 B. C. Env. Aff. L. Rev. 293 (1978).
This Court had not previously indicated that the federal common law of nuisance provided a basis for federal-question jurisdiction under 28 U. S. C. § 1331. But see Texas v. Pankey, 441 F. 2d 236 (CA10 1971). As recently as 1971, however, the Court had confirmed the existence of its original jurisdiction to consider a nuisance action brought by one State to vindicate its own sovereign interests or the interests of its citizens as a whole. See Ohio v. Wyandotte Chemicals Corp., 401 U. ,S. 493, 496 (citing cases discussed supra, at 335). The significance of Wyandotte was the Court's refusal for prudential reasons to exercise the original jurisdiction that concededly obtained. 401 U. S., at 499-505. The additional observation that “[s]o far as it appears from the present record, an action such as this, if otherwise cognizable in federal district court, would have to be adjudicated under state law,” id., at 498-499, n. 3 (emphasis added), was explained by the Court one year later as “based on the preoccupation of that litigation with public nuisance under Ohio law.” Illinois v. Milwaukee, 406 U. S., at 102, n. 3.
See Act of June 29, 1888, 25 Stat. 209. See also Rivers and Harbors Appropriation Act of 1899, 30 Stat. 1121.
Ch. 758, 62 Stat. 1155.
The Court at this point, ante, at 314^315, would rely on Arizona v. California, 373 U. S. 546 (1963), and Mobil Oil Corp. v. Higginbotham, 436 U. S. 618 (1978). But those cases do not stand for the broad proposition announced today. In Arizona v. California, Congress had developed a formula for apportioning the limited waters of the Colorado River and directed the federal agency to implement the formula. In the face of this express congressional allocation, the Court declined to substitute its own notions of an equitable apportionment. 373 U. S., at 565. In Mobil Oil Corp. v. Higginbotham, the Court confronted a statute that had created a precise federal remedy where before there had been none. Since federal law, when the statute was passed, did not address wrongful death on the high seas, and the statute itself expressed no intent to preserve or create federal remedies, the Court acceded to the particularized judgment of Congress. 436 U. S., at 625. Unlike the statutes at issue in *339those two cases, the 1972 Act addressed a broad and complex subject to which state and federal law had previously spoken, and in doing so recognized and encouraged many different approaches to controlling water pollution. See discussion in Part II, infra.
Inevitably, a federal court must acknowledge the tension between its obligation to apply the federal common law in implementing an important federal interest, and its need to exercise judicial self-restraint and defer to the will of Congress. Congress, of course, may resolve this tension by making it known that flexible and creative judicial response on a case-by-ease basis must yield to an interest in certainty under a comprehensive legislative scheme. At the same time, the fact that Congress can properly cheek the courts’ exercise of federal common law does not mean that it has done so in a specific case. This Court is no more free to disregard expressions of legislative desire to preserve federal common law than it is to overlook congressional intent to curtail it. Indeed, the Court has admonished that statutes will not be construed in derogation of the common law unless such an intent is clear. Isbrandtsen Co. v. Johnson, 343 U. S. 779, 783 (1952) (citing cases). To say that Congress “has spoken,” ante, at 316, n. 8, is only to begin the inquiry; the critical question is what Congress has said.
E. g., National Sea Clammers Assn. v. City of New York, 616 F. 2d 1222, 1233, n. 31 (CA3), cert. granted, 449 U. S. 917 (1980); California Tahoe Regional Planning Agency v. Jennings, 594 F. 2d 181, 193 (CA9), cert. denied, 444 U. S. 864 (1979). See also Illinois v. Outboard Marine Corp., 619 F. 2d 623, 626 (CA7 1980), cert. pending, No. 80-126; United States v. Atlantic-Richfield Co., 478 F. Supp. 1215, 1218-1220 (Mont. 1979); United States ex rel. Scott v. United States Steel Corp., 356 F. Supp. 556, 559 (ND III. 1973); United States v. Ira S. Bushey & Sons, Inc., 346 F. Supp. 145, 149 (Vt. 1972), aff’d, 487 F. 2d 1393 (CA2 1973), cert. denied, 417 U. S. 976 (1974).
The Court relies on Committee for Consideration of Jones Falls Sewage System v. Train, 539 F. 2d 1006, 1009, n. 9 (CA4 1976), in criticizing the “unlikely assumption” that § 505 (e) preserved anything other than “the more routine state common law.” Ante, at 329. Jones Falls offers no support for this criticism, since it concerned only intrastate pollution of navigable waters. Indeed, the court there assumed the continued applicability of federal common law where a State sought to vindicate its rights in an interstate controversy, 539 F. 2d, at 1010, but concluded that because the controversy was entirely local, the state common law of nuisance preserved by § 505 (e) furnished the relevant common-law remedy.
Cf. New Jersey v. City of New York, 283 U. S. 473, 477, 482-483 (1931) (compliance with permit requirements of federal statute does not bar injunctive relief in federal nuisance action).
It is significant that elsewhere in the statute, Congress expressly manifested an intention to foreclose the applicability of other laws. See § 312 (f)(1), 33 U. S. C. §1322 (f)(1). Congress thus demonstrated that it was capable of pre-empting a particular area when it chose to do so.
The Court points to no other judicial decision that has construed the language of § 505 (e) in this fashion. See n. 9, supra.
There is nothing new about federal law in this area being characterized by its proponents as comprehensive. Similar claims were made in *343advancing the legislation in place when Illinois v. Milwaukee was decided. See, e. g., S. Rep. No. 462, 80th Cong., 1st Sess., 1 (1947) (“The purpose of the bill (S. 418) is to provide a comprehensive program for preventing, abating, and controlling water pollution . . .”); 94 Cong. Rec. 8195 (1948) (“The bill provides that the Surgeon General shall encourage a comprehensive program for the control of stream pollution between the States and to secure their cooperation in combating this evil.” (Rep. Auchincloss)). That a different Congress, 24 years later, deemed this legislation inadequate (see ante, at 318, n. 10), carries no more significance than the postmortems one may expect from the 104th Congress concerning the 1972 Act.
See also H. R. Rep. No. 92-911, pp. 132, 134 (1972), reprinted in 1 Leg. Hist. 819, 821.
Id., at 191. See Reserve Mining Co. v. EPA, 514 F. 2d, at 501.
The Court previously has observed that Senator Muskie was perhaps the Act’s primary author, and has credited his views accordingly. See E. I. du Pont de Nemours & Co. v. Train, 430 U. S. 112, 129 (1977) ; EPA v. National Crushed Stone Assn., 449 IJ. S. 64, 71, n. 10 (1980).
See 1 Leg. Hist. 191-194. See also id., at 248 (colloquy between Reps. Dingell and Wright); id., at 252 (Rep. Dingell). The Court, ante, at 329-332, elaborately attempts to minimize the fact, recognized by all participants in the Senate colloquy, that the Reserve Mining case involved a common-law nuisance count. In seeking assurances that the pending litigation would not be "adversely affect[ed],” Senator Griffin stated explicitly that the lawsuit was based on two pre-existing federal statutes and the common law of public nuisance. 1 Leg. Hist. 190-191. Senator Muskie’s final response to Senator Griffin indicated his understanding that the suit as a whole would not be affected by the Act. Id., at 194. Moreover, Senator Hart’s reference to “other law” in the Reserve Mining case could have pertained only to the common-law counts he had not already mentioned.
This entire discussion of the Reserve Mining case was initiated due to Senator Griffin’s concern over the possible retroactive effect of § 402 (k) on litigation already commenced. Senators Muskie and Hart, as well as the EPA, took the position that there would be no disruption of the pending action, which had been commenced in February 1972, three months prior to this action. In his letter to Senator Griffin, the EPA General Counsel added a caveat that has obvious significance here:
“[I]t is reasonable to conclude that the courts will not interpret any legislation to deprive them of jurisdiction of pending litigation in the absence of clear and explicit language. There is no such clear and explicit language to this effect in the pending bill.” 1 Leg. Hist. 193.
Brief for Respondent Illinois 8-9 (describing unsuccessful pursuit of administrative remedies); see 599 F. 2d 151, 158 (CA7 1979) (describing administrative processes under statute before 1972).
As the Court observes, the scheme established by § 402 “provides a jorum for the pursuit” of a neighboring State’s claim that the controls to be imposed are not sufficiently stringent. Ante, at 326 (emphasis added). There is nothing inconsistent about making this forum available, and encouraging its use, while at the same time permitting the pursuit of other *346remedies. If there are problems with the efficiency of such an approach, Congress of course is free to modify the statutory scheme.
Following the District Court’s ruling in this case, Congressman Aspin of Wisconsin proposed an amendment to § 402:
“Sec. (a) Section 402 of the Federal Water Pollution Control Act is amended by adding at the end thereof the following new subsection:
“ ‘(1) In any case where a State whose waters may be affected by the issuance of a permit under this section fails to submit any recommendations to the permitting State as authorized in subsection (b) (5) of this section, the State failing to make such a submission (and its persons) shall not have standing to bring any action to abate (in whole or in part) as a nuisance under common law in any court of the United States any discharge which would have been the subject of such recommendations.’
“(b) The amendment made by subsection (a) of this section shall be applicable to any action brought to abate (in whole or in part) as á nuisance under common law in any court of the United States any discharge of pollutants, unless a final decision has been rendered prior to the effective date of this amendment.” App. to Brief for Respondent Illinois 98a.
The proposal was made after both Houses had debated and passed the 1977 amendments to the Act but before the Conference Committee had met. In his testimony before a House Committee considering the pending bill, Congressman Aspin voiced concern over the recent District Court decision, and suggested that Congress “explicitly express its belief that federal common law has been pre-empted.” Hearings before the House Committee on Public Works and Transportation on H. R. 3199, 95th Cong., 1st Sess., 328 (1977).
Letter to Senator Muskie from James Moorman, Assistant Attorney General, Land and Natural Resources Division, Oct. 18, 1977:
“The common law serves to give an injured party who may have been neglected by the statute or by an overburdened enforcing agency a form *347of redress. There is no good argument for removing this opportunity for remedy. The basic principle of the common law of public nuisance is that one is liable for damages caused to another where the benefit of one’s action does not outweigh the harm. This is a sound principle. Where it can be shown that pollution has injured someone it should not be a sufficient defense to claim that the generalized standards of a statute have been complied with. Polluters should properly be held to a standard that holds them liable for unnecessarily injuring others and not simply for violating the statutory law. The number of cases under the common law will inevitably be small but where they are meritorious there is no basis for abolishing this cause of action.” (Emphasis added.) App. to Brief for Respondent Illinois 101a-103a.
See, e. g., Illinois v. Outboard Marine Corp., 619 F. 2d 623 (CA7 1980), cert. pending, No. 80-126; United States v. Hooker Chemicals & Plastic Corp., (WDNY No. 79-990, filed Dec. 20, 1979). Several courts have held that the United States can state a claim for relief under the federal common law of nuisance. See, e. g., United States v. Ira S. Bushey & Sons, Inc., 346 F. Supp. 145 (Vt. 1972), aff’d, 487 F. 2d 1393 (CA2 1973), cert. denied, 417 U. S. 976 (1974); United States v. Solvents Recovery Serv., 496 F. Supp. 1127 (Conn. 1980).
Restatement (Second) of Torts §821B (Tent. Draft No. 16, 1970). See generally W. Prosser, Law of Torts 583-591 (4th ed. 1971); W. Rodgers, Environmental Law 102-107 (1977).
See Restatement (Second) of Torts §821B; Prosser, at 602-606; Note, Federal Common Law in Interstate Water Pollution Disputes, 1973 U. Ill. Law Forum 141, 154-158.
See, e. g., Reserve Mining Co. v. EPA, 514 F. 2d 492, 506-540 (CA8 1975) (en banc); United States v. Armco Steel Corp., 333 F. Supp. 1073, 1079-1084 (SD Tex. 1971); Commonwealth v. Barnes & Tucker Co., 455 Pa. 392, 319 A. 2d 871 (1974); Boomer v. Atlantic Cement Co., 26 N. Y. 2d 219, 257 N. E. 2d 870 (1970); People ex rel. Stream Control Comm’n v. Port Huron, 305 Mich. 153, 9 N. W. 2d 41 (1943); Board of Comm’rs v. Elm Grove Mining Co., 122 W. Va. 442, 9 S. E. 2d 813 (1940); Fink v. Board of Trustees, 71 Ill. App. 2d 276, 218 N. E. 2d 240 (1966); Murphysboro v. Sanitary Water Board, 10 Ill. App. 2d 111, 134 N. E. 2d 522 (1956). Thus, there can be no merit to the Court’s suggestion, ante, at 325, that the technical difficulty of the subject matter renders inappropriate any recourse to the common law. The complexity of a properly presented federal question is hardly a suitable basis for denying federal courts the power to adjudicate. Indeed, the expert agency charged with administering the Act has not hesitated to invoke this common-law jurisdiction where appropriate.
Moreover, that the District Court may have abused its discretion is no basis for concluding that state-law standards are irrelevant to the federal common law.
5 99 F. 2d, at 167-168. See also unpublished order of the Court of Appeals, App. to Pet. for Cert. B-2 to B-4; unpublished findings of fact and conclusions of law of the District Court, id., at F-l to F-30.
There is little to be gained by undertaking an extensive review of the record evidence on these points. The Court of Appeals did this and concluded that the findings at trial were not clearly erroneous. I see no reason to disturb the Court of Appeals’ view of the evidence.
Congress in 1977 amended the Act to permit the Administrator to grant extensions of the 1977 deadline under certain conditions. See Pub. L. 95-217, §§ 44, 45, 91 Stat. 1584, 33 U. S. C. §§ 1311 (h) and (i) (1976 ed., Supp. III).
Pub. L. 95-217, §70, 91 Stat. 1608. See S. Rep. No. 95-370, p. 81 (1977). The study was issued in October 1978. See EPA, Report to Congress on Control of Combined Sewer Overflow in the United States (MCD-50, 1978).
See 40 CFR §§ 133.102 and 133.103 (1980). In addition, sewers and pipes that do not lead to a treatment facility are not considered “publicly owned treatment works” for purposes of §301,. 33 U. S. C. § 1311. See 40 CFR § 122.3, p. 70 (1980). In the absence of technology-based treatment requirements for combined sewer overflows, the Administrator mandates an individualized analysis by each system that seeks federal assistance. See EPA, Benefit Analysis for Combined Sewer Overflow Control 3 (1979).
While the Wisconsin permit-granting agency and the Wisconsin state courts devised one approach to regulating combined sewer overflows in the Milwaukee system, this alone does not establish that the applicable legal standard under federal common law is the one adopted by Wisconsin. To hold otherwise would in effect nullify a neighboring State’s more stringent pollution control standards even in circumstances where, as here, a significant risk of harm to the neighboring State’s citizenry has been established; if a polluting State is not violating its own approved standards, a neighboring State with higher standards then has no recourse under the Act. It is in precisely this context that the Court recognized the significance of federal common law. Illinois v. Milwaukee, 406 U. S., at 107-108.