With that out of the way: not every environmental enforcement action starts with a government inspector. Sometimes it begins with a private citizen group, a 60-day notice letter, and a threat to sue. That mechanism, the citizen suit, is back in the news, with courts and the administration fighting over how far it reaches. But the legal fight isn’t really the story here. The key takeaway: regardless of how these cases resolve, the data that fuels citizen suits is public today, and that’s where EHS leaders’ attention should stay focused.

What Is a Citizen Suit?

A citizen suit is a private lawsuit brought by an individual, an NGO, or in some cases even a local government, to enforce an environmental statute directly against a regulated entity rather than waiting on an agency to act. Congress built these provisions into major environmental laws starting in the 1970s, so citizens could bring lawsuits to stop violations, typically where the federal government should have been acting but wasn’t.

Most people associate citizen suits with the Clean Water Act (CWA), but the mechanism also sits in the Clean Air Act, CERCLA (Superfund), the Safe Drinking Water Act, RCRA, and the Toxic Substances Control Act. RCRA’s version is worth flagging, since it lets plaintiffs seek injunctive relief against an “imminent and substantial endangerment,” even absent a permit violation. Still, most citizen suits I’ve seen target persistent CWA noncompliance.

A plaintiff generally must send a 60-day notice letter before filing (90 days under RCRA). Plaintiffs also need standing, such as a riverkeeper whose waterway is impacted. If a government enforcement action is already underway, the suit is precluded.

The Supreme Court Recently Had Its Chance to Limit Citizen Suits

On June 30, 2025, the Supreme Court declined to hear two cases industry had hoped would narrow citizen suit standing. In Port of Tacoma v. Puget Soundkeeper Alliance, the Ninth Circuit had ruled that citizen groups can enforce the full terms of a state-issued CWA permit in federal court, even where the state’s requirements exceed the federal minimum. DOJ’s Solicitor General urged the Court to grant review, but it denied cert without explanation. The Court also let stand the Fifth Circuit’s ruling in ExxonMobil v. Environment Texas Citizen Lobby, closing out long-running litigation over a broad Clean Air Act standing theory. Leaving both rulings intact means citizen groups keep these enforcement tools.

Then the Fight Moved to a Different Argument

A newer challenge argues something more structural: that citizen suits improperly hand executive power to private parties. The Pacific Legal Foundation, representing Springfield, Tennessee, in a CWA suit brought by the Tennessee Riverkeeper, argues that the citizen suit provision is itself an unconstitutional delegation. DOJ has since raised the same delegation theory in a separate Mississippi case, moving to intervene on national-security grounds.

But the Administration Recently Signed Off on Joining a Citizen Suit

Months earlier, DOJ’s own actions seemed to cut against that argument. In November 2025, DOJ and EPA announced a proposed consent decree with Hanover Foods over more than 600 permit exceedances at its Pennsylvania wastewater plant. NGOs had reviewed Hanover’s public discharge monitoring reports, spotted the pattern, and filed a citizen suit; EPA, DOJ, and Pennsylvania’s environmental agency eventually joined it, settling for a $1.15 million penalty and a mandated treatment overhaul.

That’s not necessarily hypocrisy – a litigation position in one case and a broader enforcement posture in another can move independently. But it’s a reminder that, whatever happens to the constitutional argument, the government hasn’t stepped back from citizen-suit-driven settlements in practice.

Why This Matters Regardless of How the Cases Resolve

The constitutional challenges target the citizen suit mechanism itself, but they don’t touch the data that fuels it. The CWA’s permitting system requires facilities to self-report effluent data, that is publicly accessible through EPA’s ECHO database and state portals. The Hanover case shows how little it takes to start one – an outside group reading a facility’s numbers against its permit limits. That capability keeps growing regardless of how the executive-power challenges in Tennessee and Mississippi are resolved.

What This Means for EHS Leaders

Given how much of this issue has focused on the constitutional fight, it’s tempting to treat that as the headline and wait to see how it resolves – probably a multi-year process. But that’s the wrong signal. The mechanism generating real exposure right now isn’t sitting in a courtroom; it’s sitting in your discharge monitoring reports, permit files, and ECHO record, all fully public today.

Citizen suits are alive and functioning today, and compliance data is readily available to any private party that wants to look. So, the practical question isn’t whether citizen suits survive this fight. It’s this: if an outside entity reviewed your last three years of self-reported data today, what would they find?

Until next week,

Doug Parker

CEO, Ecolumix

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Coming in future issues:

Inside a Critical Incident: Regulators build a timeline: pre-incident decisions, technical failure, post-incident conduct. Each phase can signal different culpability. That’s the sequence EHS leaders need to understand.

EPA’s National Compliance Initiatives: The EPA lays out its compliance and enforcement priorities. Here is what you need to understand about them as an EHS leader.

Questions or topics worth covering? Reach out: doug@ecolumix.com