Master Sixth Circuit decision limiting federal avenues for a foreign sovereign's cross-border water-pollution suit while preserving a source-state common-law nuisance claim. with this comprehensive case brief.
Her Majesty the Queen in Right of Ontario v. City of Detroit sits at the intersection of environmental law, federal courts, and international relations. The case arises from alleged cross-border pollution in the Great Lakes system and asks which legal tools—federal common law, federal statutes, treaties, or state common law—a foreign sovereign may use in U.S. courts to enjoin pollution originating in the United States but harming interests in Canada.
The decision is especially significant because it synthesizes three landmark legal threads: (1) the Supreme Court's displacement of federal common-law nuisance claims by the Clean Water Act (CWA), (2) rigorous statutory limits on who may bring CWA citizen suits, and (3) the Supreme Court's "source-state law" approach to state common-law nuisance claims for interstate (and, by extension, international) water pollution. It also underscores that treaties like the Boundary Waters Treaty of 1909 do not, without clear textual direction, create privately enforceable rights in domestic courts. For law students, the case is a compact study in preemption, jurisdiction, treaty enforcement, and the residual role of state law after sweeping federal regulatory schemes.
874 F.2d 332 (6th Cir. 1989) (U.S. Court of Appeals for the Sixth Circuit)
The Province of Ontario (suing in the name of Her Majesty the Queen in Right of Ontario) brought suit against the City of Detroit, a Michigan municipal corporation that owns and operates wastewater and sewer systems discharging into the Detroit River and Lake St. Clair—navigable waters of the United States forming part of the international boundary. Ontario alleged that Detroit's treatment plant discharges and combined sewer overflows released inadequately treated effluent, causing bacterial contamination and other pollution that drifted into Canadian waters and shorelines, resulting in beach closures, health risks, and environmental harms in Ontario. Ontario sought injunctive relief and other remedies under several legal theories: (1) federal common-law public nuisance; (2) the Clean Water Act's citizen-suit provision to enforce alleged violations of Detroit's National Pollutant Discharge Elimination System (NPDES) permit; (3) the Boundary Waters Treaty of 1909; and (4) state-law public nuisance. The district court dismissed Ontario's federal claims, concluding that the CWA displaced federal common law, that Ontario was not a proper 'citizen' under the CWA's citizen-suit statute, and that the Treaty provided no private right of action. The court declined to proceed on state-law claims. Ontario appealed.
Can a foreign sovereign maintain federal common-law, Clean Water Act citizen-suit, or treaty-based claims in U.S. court to abate cross-border water pollution from a U.S. source, and, if not, may it nevertheless pursue a state common-law public nuisance claim under the source state's law?
1) When Congress has spoken directly and comprehensively to an issue, federal common law is displaced. The Clean Water Act's comprehensive scheme for regulating discharges into navigable waters displaces federal common-law nuisance for water pollution. See City of Milwaukee v. Illinois (Milwaukee II), 451 U.S. 304 (1981). 2) The CWA citizen-suit provision, 33 U.S.C. § 1365, authorizes suit by a 'citizen'—defined in § 1365(g) as a 'person or persons having an interest which is or may be adversely affected.' 'Person' is separately defined in 33 U.S.C. § 1362(5) and does not include foreign sovereigns. Thus, a foreign sovereign is not a 'citizen' for § 1365 purposes. 3) Treaties do not create privately enforceable rights in domestic courts absent clear textual indication or implementing legislation conferring such a right. The Boundary Waters Treaty of 1909 channels disputes to governmental and International Joint Commission processes and contains no private right of action. 4) The CWA does not preempt state common-law nuisance claims brought under the law of the source state of the pollution; plaintiffs must proceed, if at all, under the source state's law. See International Paper Co. v. Ouellette, 479 U.S. 481 (1987). 5) A foreign state may invoke alienage jurisdiction under 28 U.S.C. § 1332(a)(4) to sue a citizen of a U.S. state if other jurisdictional prerequisites are met.
The Sixth Circuit affirmed dismissal of Ontario's federal claims: (a) the CWA displaces federal common-law nuisance for water pollution; (b) Ontario, as a foreign sovereign, is not a 'citizen' under the CWA and thus cannot bring a § 1365 citizen suit; and (c) the Boundary Waters Treaty of 1909 creates no private right of action. However, consistent with Ouellette and the CWA's savings clauses, the court recognized that Ontario may pursue a state-law public nuisance claim under Michigan (the source state's) law; such a claim is not preempted by the CWA. The matter was remanded to allow consideration of the source-state common-law claim, with jurisdictional footing available via alienage jurisdiction if properly alleged.
Federal common law: Relying on Milwaukee II, the court explained that once Congress enacted a comprehensive statutory and regulatory scheme governing a field—in this case, the CWA's permitting, effluent limitations, and enforcement architecture—federal common-law nuisance is displaced. The international character of the alleged injury did not alter Congress's intent to centralize water-pollution control within the CWA framework. Permitting (NPDES), administrative oversight, and specified enforcement mechanisms are exclusive federal tools for managing discharges to U.S. navigable waters; courts may not revive federal common law simply because a foreign sovereign is the complainant. CWA citizen suit: The court turned to statutory text. Section 505 authorizes suit by a 'citizen,' defined as a 'person' with a cognizable interest. The CWA's definition of 'person' does not include foreign sovereigns; it lists individuals, corporations, associations, states, municipalities, and certain intergovernmental bodies, but not foreign governments. Congress knows how to include sovereigns when it wishes to do so (as evidenced elsewhere in federal law), and its omission here was dispositive. Accordingly, Ontario could not proceed via the citizen-suit route to enforce Detroit's permit. Treaty claim: The Boundary Waters Treaty provides an intergovernmental framework for addressing cross-border water issues and assigns roles to the International Joint Commission. It says nothing about private or subnational governmental enforcement in domestic courts. Under established principles of treaty interpretation and federal common law regarding private rights, courts will not infer a private cause of action absent clear textual indication or implementing legislation. Finding none, the court rejected Ontario's treaty-based claim. State common-law claim and preemption: The court emphasized that the CWA preserves an important role for state law. Under Ouellette, a plaintiff affected by out-of-state (or foreign-border) pollution may bring a nuisance action under the law of the source state, not the affected state. That approach preserves uniformity around the source's NPDES permitting while leaving room for common-law remedies that do not conflict with federal standards. Michigan is the source state here, so Ontario may press a Michigan common-law nuisance claim. The court noted that federal jurisdiction over that claim could rest on alienage jurisdiction under 28 U.S.C. § 1332(a)(4), provided the jurisdictional allegations and amount-in-controversy requirements are satisfied or amended consistent with 28 U.S.C. § 1653. The case was therefore remanded for further proceedings on the source-state claim.
For environmental and federal courts doctrine, the case crystallizes three lessons. First, the CWA's comprehensive scheme forecloses federal common-law nuisance claims for water pollution, even in international contexts. Second, the CWA's citizen-suit provision is strictly construed—foreign sovereigns are not 'citizens' and cannot use § 505 to enforce U.S. permits. Third, consistent with Ouellette, plaintiffs harmed by cross-border pollution retain a pathway through state common-law nuisance under the source state's law, preserving a limited but meaningful role for state tort remedies alongside the federal regulatory regime. For law students, the case is a model of statutory displacement, treaty non-self-execution in practice, and the nuanced coexistence of federal regulation and state tort law.
The Supreme Court in Milwaukee II held that when Congress provides a comprehensive regulatory framework governing a field—in this case, water pollution via the CWA's permitting, effluent limitations, and enforcement mechanisms—federal common law is displaced. The Sixth Circuit applied that principle, reasoning that allowing federal common-law nuisance would undermine Congress's chosen scheme and create parallel, potentially conflicting standards for water quality and enforcement.
No. The CWA's citizen-suit provision, 33 U.S.C. § 1365, authorizes suit by a 'citizen,' defined as a 'person' adversely affected. The Act's definition of 'person' does not include foreign sovereigns. Because Ontario is a foreign state, it does not qualify as a 'citizen' and cannot sue under § 505. Congress's deliberate omission controls, and courts will not expand the definition beyond the statute's text.
No. The Treaty establishes intergovernmental mechanisms and the International Joint Commission to address cross-border water issues. It does not contain language granting private parties or subnational governments a right to sue in domestic courts, nor is there implementing legislation creating such a cause of action. Under U.S. law, treaties are not privately enforceable absent clear text or legislation creating a private right, so the treaty claim was dismissed.
They may bring a state common-law nuisance claim under the law of the source state (here, Michigan), consistent with International Paper Co. v. Ouellette. The CWA's savings clauses and Ouellette preserve such claims because they do not inherently conflict with the federal permitting regime. Federal subject-matter jurisdiction over that state-law claim can be based on alienage jurisdiction under 28 U.S.C. § 1332(a)(4), assuming the jurisdictional prerequisites are satisfied.
No. It bars certain federal claims: federal common-law nuisance (displaced by the CWA), CWA citizen suits (§ 505) by foreign sovereigns, and private treaty enforcement. But foreign sovereigns can still pursue source-state common-law nuisance and may also prompt enforcement through diplomatic channels, the International Joint Commission, or by engaging U.S. federal and state regulators with primary enforcement authority under the CWA.
Ouellette holds that common-law nuisance claims arising from out-of-state pollution are not preempted if brought under the source state's law; they are preempted if brought under the affected state's law. Applying that rule, the Sixth Circuit recognized that Ontario could sue under Michigan nuisance law (the source state), harmonizing state tort remedies with the CWA's uniform permitting structure.
Her Majesty the Queen in Right of Ontario v. City of Detroit illustrates how the Clean Water Act both centralizes federal control over water-pollution regulation and limits federal-court pathways for private and foreign sovereign plaintiffs. The court applied Milwaukee II to foreclose federal common-law nuisance, adhered strictly to the statute's citizen-suit definitions, and rejected a private right under the Boundary Waters Treaty—all to protect the integrity of Congress's chosen regulatory scheme.
At the same time, the decision preserves a crucial role for state tort law. Consistent with Ouellette, cross-border plaintiffs may proceed under the source state's common law, ensuring there is still a judicial remedy compatible with the CWA. For practitioners and students, the case underscores the importance of carefully selecting the legal theory, forum, and governing law in environmental disputes—especially where international borders and comprehensive federal statutes converge.
Need to cite this case?
Generate a perfectly formatted Bluebook citation in seconds.
Use our Bluebook Citation Generator →