Key Contacts
Practice Areas
Supreme Court Invalidates Use of “End-Result” NPDES Requirements that Condition Compliance on Receiving Water Quality
The U.S. Supreme Court has ruled that pollutant discharge permits issued under the Clean Water Act (CWA) National Pollutant Discharge Elimination (NPDES) program cannot condition compliance on the receiving waterbody achieving a certain “end-result” such as meeting water quality standards, but instead must specifically set forth what a permittee must do or refrain from doing to comply with the permit. The City and County of San Francisco (“San Francisco”) had challenged two such end-result requirements that were added to the NPDES discharge permit for its Oceanside facility by the U.S. Environmental Protection Agency (EPA) and state permitting agency during the permit renewal process. One provision prohibited any discharge that contributes to a violation of any applicable water quality standard for the receiving water and the other restricted any discharge that creates pollution, contamination or nuisance as defined by the California Water Code. San Francisco appealed to the Supreme Court after having its challenge rejected by both EPA’s Environmental Appeals Board and the Ninth Circuit Court of Appeals.
In a March 4, 2025, majority opinion, authored by Justice Alito, in the City and County of San Francisco v. EPA, the Supreme Court held that the two challenged provisions exceed EPA’s authority under the CWA and are not necessary to protect water quality. Rather than making a permittee responsible for the overall water quality of a waterbody into which it discharges pollutants, the Court ruled that EPA must determine what is necessary to protect water quality in the waterbody and then establish appropriate specific and direct requirements and restrictions in the NPDES permit. The Court ruled that it is EPA’s responsibility to determine the necessary steps for ensuring water quality and that Congress has given it the necessary tools to make such determination.
The Court noted that a permittee with an end-result requirement in its permit could face crushing penalties under the CWA if the water quality in the receiving waterbody falls below the established standards, even though the permittee otherwise followed to-the-letter all the specific requirements of its permit. The Court ruled that Congress could not have intended this result. Looking back at the history of the CWA, the Court observed that the 1972 amendments to the predecessor statute were intended to abolish a backward-looking framework that allowed for enforcement actions against dischargers that caused an exceedance of water quality standards, with a forward-looking framework that established direct restrictions in the form of permit requirements applicable to each discharger. Permittees who fail to comply with permit requirements can face significant penalties, however, those who abide by their permit terms are deemed to be in compliance with the CWA under what is known as the “permit shield.” The Court ruled that an end-result requirement is not a type of permit limitation authorized under the CWA.
Justice Barrett, joined by Justices Sotomayor, Kagan and Jackson, filed a dissent in the case arguing that the challenged permit conditions are indeed limitations authorized under the CWA and rejecting the characterization of the statutory history as set forth in the majority position. The dissent argued that the 1972 amendments creating the modern CWA rendered all discharges presumptively unlawful unless authorized under the new permitting regime. Those permits, it argued, can impose a prospective requirement on permittees to comply with water quality standards.
Both the majority opinion and the dissent were on common ground in terms of rejecting San Francisco’s leading argument that all “limitations” under the CWA must qualify as “effluent limitations.” Effluent limitations, as defined in the CWA, refer to restrictions on “quantities, rates, and concentrations of chemical, physical, biological, and other constituents” in a regulated discharge. Both agreed that the CWA authorizes EPA to impose effluent limitations as well as other limitations, including non-numerical operational practices.
The majority opinion stated explicitly that this case is not about whether narrative limits are authorized under the CWA but instead involves the question of end-result requirements. The Court noted that it is common for NPDES permits to contain narrative limitations and requirements, such as best management practices and other requirements “that do not set numerical limitations on allowed discharges” and this decision allows such requirements.
If you have questions about this article or NPDES permit requirements, please contact Brenda Gotanda at bgotanda@mankogold.com.
