Note from the Editor: The Federalist Society takes no positions on particular legal and public policy matters. Any expressions of opinion are those of the author. We welcome responses to the views presented here. To join the debate, please email us at [email protected].

On May 27, 2025, the United States filed an amicus brief in a case testing the limits on citizen suits under the Clean Water Act (CWA), likely signaling the administration’s skepticism toward the breadth of such actions. Such skepticism is justified, although environmental advocates have argued that this petition may present vehicle problems.

The question presented in Port of Tacoma v. Puget Soundkeeper Alliance is whether a private group, suing under the citizen-suit provision of the CWA may sue in federal court to enforce the terms of a state-issued permit that go beyond the requirements of the federal statute.

States administer certain components of the CWA under delegation from the federal government once they receive clearance from the Environmental Protection Agency. In this case, an administrative agency of the State of Washington issued a permit to the owners and operators of the port under the auspices of the CWA National Pollutant Discharge Elimination System (NPDES) program. According to petitioners, this permit included terms that go beyond the requirements of that legislation. In other words, they contend, it included terms that owe their origin to state rather than federal law. Per the statute, federal authorities lack authority to enforce such non-federal terms. Petitioners therefore argue, with support from the United States as amicus curiae, that allowing private groups to undertake such enforcement would create the anomaly that they would have greater enforcement authority under the statute in federal court than the federal government. Petitioners also argue, again with support from the United States and other amici, that given a natural reading, the CWA only authorizes private groups to sue in federal court to enforce the federal components of an NPDES permit.

Applying circuit precedent, the Ninth Circuit held that the “plain language” of the Clean Water Act allows private groups to sue to enforce any provision of an NPDES permit, even one that owes its origins to state law. As the Ninth Circuit viewed it, the CWA allows a private party to sue in federal court to enforce “all” conditions of a permit issued under the NPDES program, not just those that derive from federal law. The Ninth Circuit acknowledged that its approach to this issue differs from that of the Second Circuit, which previously held that state-based conditions in NPDES permits are not enforceable in federal court via a citizen suit.

In addition to defending the decision below, respondents also argue that the case is a poor vehicle for resolution of the issue presented. Among other things, they argue that the decision below rests on multiple grounds. They reiterate and elaborate on this point in a supplemental brief filed in response to the United States’ brief. They therefore contend that the Supreme Court could not alter the outcome of the case, even if it held in petitioners’ favor. It is not clear, however, that the Ninth Circuit actually rested its decision on any alternative grounds.

Assuming the vehicle issues can be navigated, this case would enable the Court not only to resolve an apparent circuit split, but also to take up the general subject of citizen suits, which cohere awkwardly with the unitary executive and which often push the boundaries of standing. This case also presents interesting questions about states’ ability to control enforcement of their own substantive law.

As Justice Kennedy wrote in his concurrence in Friends of the Earth, Inc. v. Laidlaw Environmental Services (TOC), Inc., “[d]ifficult and fundamental questions” arise when private parties exercise a power that the Constitution commits to the executive. Dissenting in the same case, Justice Scalia, joined by Justice Thomas, noted that the Clean Water Act “turns over to private citizens the function of enforcing the law.” This is problematic. If Congress’s purpose in authorizing private citizens to enforce federal statutes is to enable private citizens to look over the shoulder of the executive with an eye toward correcting for under-enforcement, citizen suits are in tension with the unitary executive. We elect a president, who is accountable to the entire electorate, precisely to exercise discretion in enforcing federal laws. Authorizing private parties, who are accountable to only a margin of the population, to second-guess the president goes against the grain of the unitary executive and therefore may be constitutionally suspect.

To be sure, citizen suits can enable people with a legitimate injury-in-fact, but also some impediment to suing for nuisance, to seek redress for past injuries or to forestall future injuries. But many parties who bring actions under citizen-suit provisions of federal law lack injury in such a deep and abiding sense. This gives rise to a couple of pathologies. For one thing, true plaintiffs with real injuries can assert damages that are relatively amenable to measurement. Plaintiffs whose injuries are fundamentally ideological cannot. In addition, true plaintiffs with real injuries have an incentive to hold their attorneys accountable for the proceeds of judgment. But if damages are merely nominal, as is often the case with citizen suits, then the proceeds of litigation become a form of “Monopoly money.” They are thus amenable to private appropriation, with money flowing to charitable causes identified by the plaintiffs and agreed to by the defendants outside the protocols ordained by the Constitution.

Whether this case is a good vehicle for addressing these issues is an interesting question, but these issues do merit the Court’s attention.