In March 2025, the Supreme Court handed industrial dischargers what looked like a landmark victory. In City and County of San Francisco v. EPA, the Court held that “end-result” provisions in NPDES permits (provisions that make a permittee responsible for the quality of its receiving waters rather than spelling out what the permittee must do) exceed EPA’s authority under the Clean Water Act. The decision reversed the Ninth Circuit, rejected decades of EPA permitting practice, and appeared to pull the rug out from under one of the most commonly alleged categories of permit violations in citizen suits: receiving water limitations.
If you operate an industrial facility in California, you might reasonably have concluded that CCSF eliminated your exposure to receiving water violation claims. But plaintiffs’ attorneys have moved quickly to limit the decision’s reach, and they have had some early success at the trial-court level.
What CCSF Actually Held
The Court’s holding was narrow and specific. Section 1311(b)(1)(C) of the CWA authorizes permit writers to impose “any more stringent limitation” necessary to meet water quality standards, but the Court concluded that a “limitation” must be a restriction “imposed from without” that tells a permittee what it must do. On the Court’s reading, provisions that simply make a permittee responsible for ambient water quality outcomes without specifying concrete steps are not “limitations” under the statute. The Court emphasized that determining what steps a permittee must take is EPA’s responsibility, not the permittee’s.
Notably, the Court affirmed that narrative permit provisions requiring compliance with “best-management practices” and “operational requirements and prohibitions” remain valid. The decision appears to have invalidated only the open-ended, end-result variety, the kind that could expose a fully compliant permittee to penalties if receiving water quality drops for reasons beyond the permittee’s control.
Why Plaintiffs Say It Hasn’t Shut Down Citizen Suits
The gap for facility operators is that CCSF addressed what EPA can lawfully put into a permit. It did not directly address what happens to end-result provisions that are already in permits, including California’s Industrial General Permit, when a citizen suit plaintiff seeks to enforce them. Plaintiffs have seized on that gap, and at least one trial court has so far agreed with them.
Plaintiffs rely on a different line of authority. In Northwest Environmental Advocates v. City of Portland (“NWEA II”), the Ninth Circuit held in 1995 that “the plain language of CWA § 505 authorizes citizens to enforce all permit conditions,” including water quality standards that have not been translated into numeric effluent limitations. Plaintiffs contend that NWEA II remains binding circuit precedent and that CCSF did not displace it. Plaintiffs also invoke Puget Soundkeeper Alliance v. Port of Tacoma, in which the Ninth Circuit held that federal courts “will not consider collateral attacks on the validity of permit conditions in the course of an enforcement action or citizen suit.” As plaintiffs frame it, the practical effect is that any attempt to use CCSF as a defense in an enforcement case is a barred collateral attack on permit validity.
The first major test came in San Francisco Baykeeper v. City of Sunnyvale, where the defendants argued that CCSF rendered every end-result provision in their NPDES permits null and void. Judge Davila sided with the plaintiffs and rejected the defendants’ argument. He found that CCSF and NWEA II are in “tension” but “not clearly inconsistent,” because, in his view, they address different questions: CCSF concerns permit validity, while NWEA II governs citizen-suit enforceability. Under Ninth Circuit rules, a district court must follow circuit precedent unless the intervening Supreme Court decision is “clearly inconsistent,” and Judge Davila concluded it is not.
The result, at least for now: under the Sunnyvale approach, receiving water provisions remain enforceable in citizen suits “in the interim,” unless and until the permitting agency removes them or the Ninth Circuit revisits NWEA II.
The Bigger Question: Has CCSF Been Read Out of Existence?
It is worth stepping back and considering what this line of argument does to CCSF as a practical matter. The Supreme Court held that end-result provisions are not “limitations” under the CWA, concluding that they exceed EPA’s authority and expose permittees to liability for ambient conditions they may not control. But the approach plaintiffs have advanced, and that Judge Davila adopted, appears to interpret CCSF so narrowly that its holding has little operative effect in the enforcement context where it matters most to facility operators. If end-result provisions remain enforceable in citizen suits despite the Supreme Court’s conclusion that they are not valid “limitations,” one could fairly ask whether CCSF has been given any meaningful force at all, or whether it has been largely read out of the picture at the district court level.
We suspect this issue is far from settled. Judge Davila’s order is a district court ruling on a motion for reconsideration, not a published Ninth Circuit opinion. The tension he acknowledged between CCSF and NWEA II is real, and it is the kind of tension that typically gets resolved on appeal. There are also arguments that defendants may be able to deploy going forward (including narrow § 1365(f) “tethering” theories challenging whether ambient-only allegations state a claim under the citizen suit provision as CCSF defines it) that have not yet been fully tested. Whether the Ninth Circuit ultimately concludes that CCSF displaced NWEA II, or that some version of the Sunnyvale approach should hold, remains an open question. This is an area where the law is actively developing, and facility operators should expect further litigation.
In the meantime, the most productive path is to ensure that your compliance posture is strong enough that plaintiffs cannot build a viable case from SMARTS data in the first place. That means current SWPPPs, documented BMPs, timely sampling, and complete reporting, regardless of how the courts ultimately resolve CCSF’s effect on receiving water claims.
Sunnyvale also points to where this issue may be most effectively addressed: the permit itself. Because the Sunnyvale approach leaves end-result provisions enforceable only so long as they remain in the permit, permittees should consider end-result limitations carefully in the context of permit renewals and amendments. CCSF provides strong support for objecting to, and seeking the removal or revision of, open-ended receiving water provisions during the permitting process, which may prove a more reliable way to limit exposure than raising CCSF as a defense after a citizen suit is filed.
If you have questions about how CCSF may affect your facility’s exposure or have received a 60-Day Notice citing receiving water violations, contact the Allen Matkins environmental team.
California Stormwater Defense is published by Allen Matkins Leck Gamble Mallory & Natsis LLP. Nothing in this post constitutes legal advice. Contact us for a consultation specific to your facility.