​The Supreme Court today ruled in favor of San Francisco in the case City and County of San Francisco v. Environmental Protection Agency, impacting the enforcement of the Clean Water Act (CWA). In a 5-4 decision, the Court determined that the Environmental Protection Agency (EPA) exceeded its authority by imposing vague, narrative-based limitations on water quality in National Pollutant Discharge Elimination System (NPDES) permits.

San Francisco operates a combined sewer system that collects both sewage and stormwater runoff. During heavy rains, this system can overflow, discharging pollutants into the Pacific Ocean. To regulate such discharges, the EPA issued NPDES permits containing general prohibitions against violating water quality standards. The city challenged these provisions, arguing they were too vague and lacked specific discharge limits, making compliance and enforcement challenging. ​

The Supreme Court agreed with San Francisco, stating that the EPA must set specific, measurable limits on discharges rather than relying on broad, narrative standards. Justice Samuel Alito, writing for the majority, emphasized that the EPA has the tools to obtain necessary information from permit holders without resorting to such vague requirements. ​

This ruling signifies a shift in how the EPA can enforce water quality standards, requiring more precise and quantifiable limitations in permits. The decision has broader implications for municipalities and industries nationwide, potentially easing regulatory burdens while raising concerns about maintaining water quality standards.

CITY AND COUNTY OF SAN FRANCISCO, CALIFORNIA v. ENVIRONMENTAL PROTECTION AGENCY – March 4, 2025