Ari Blemur, Senior Staff Member, 3L

The Supreme Court of the United States (SCOTUS) reached a 5-4 decision in City and County of San Francisco, California v. Environmental Protection Agency on March 4th, 2025 to effectively limit the Environmental Protection Agency’s (EPA) ability to regulate water pollutant standards under the Clean Water Act (CWA). Under the CWA, the EPA and authorized state agencies can impose requirements on entities that want to discharge pollutants, such as sewage, garbage, and chemical waste, into U.S. water. The EPA and authorized state agencies imposed these requirements through the National Pollutant Discharge Elimination System (NPDES), which makes it unlawful to discharge pollutants into American waters unless authorized by permit.

Historically, the city of San Francisco had their permit renewed under this system without issue. Then, in 2019, the EPA added two new “end-result” requirements conditioning compliance on receiving water quality to San Francisco’s permit: (1) San Francisco may not make any discharge that contributes to a violation of water quality standards for the receiving waters, and (2) San Francisco may not create “pollution, contamination, or nuisance” under California Water Code § 13050. The receiving waters the EPA referred to are those that receive the regulated discharge. The EPA measures whether a discharge was permissible by the effect on the water receiving the discharge, rather than the discharge itself, and references any discharge receiving waters as “receiving waters.” 

Violating these standards would result in significant civil fines and potentially criminal penalties. However, these ordinances don’t tell the city what to do. This was problematic for San Francisco because natural events beyond the city’s control, such as heavy rainfall, cause excess flow from the stormwater and wastewater treatment facilities, resulting in untreated sewage and stormwater being discharged into the Bay and the Pacific Ocean.

For this reason, the city of San Francisco petitioned the Ninth Circuit for review of the end-result requirement decree, stating that the new impositions were outside the scope of what the EPA is allowed to do in regulating water pollution. The Ninth Circuit ruled in favor of the EPA, stating that it authorizes the EPA to impose “any” limitations ensuring applicable water quality standards are satisfied in a receiving body of water. San Francisco then appealed to SCOTUS, which granted certiorari.

Justice Alito, joined by Justices Roberts, Kavanaugh, and Thomas, and, in part, Justice Gorsuch, reversed the Ninth Circuit and held that the CWA and NPDES do not allow the EPA to impose end-result requirements that condition compliance on receiving water quality. All limitations must state the concrete actions a permittee must take to meet the requirements imposed by the regulating authority. Accordingly, end-result requirements are not limitations because they do not restrict conduct; rather, they only require a result. If the EPA could use end-result clauses, permittees would face massive penalties for factors beyond their control, because the CWA imposes strict liability. Moreover, the CWA is designed to control sources of pollution, not hold dischargers strictly liable for ambient water quality they cannot fully control. The longstanding NPDES framework relies on technology-based and water quality-based effluent limits–limits that specify the quantity of enumerated pollutants that may be discharged. The majority clarified that narrative limits on efforts to keep receiving waters clean, such as requiring best management practices, remain valid, but tying legal compliance to whether the water actually meets the standards is not.

Justice Barrett, joined by Justices Sotomayor, Kagan, and Jackson, dissented in part, deferring to the EPA by arguing that the CWA’s broad language permits the requirements the EPA tried to implement and that the EPA must have the authority to regulate ambient water quality. The majority ruling exhibits the new regime of judicial discretion under Loper Bright Enterprises v. Raimondo. With agency power now limited to judicial review (and, ultimately, judicial discretion), we will likely continue to see rulings that limit the EPA’s power.