EPA Loses Supreme Court Battle Over San Francisco Wastewater Pollution Limits

The U.S. Supreme Court has issued a 5-4 ruling that significantly limits the Environmental Protection Agency’s (EPA) authority under the Clean Water Act (CWA). On March 4, 2025, the Court overturned a 9th Circuit decision that upheld the EPA’s National Pollutant Discharge Elimination System (NPDES) permit for the City and County of San Francisco's combined sewer overflow (CSO). This ruling narrows the EPA’s ability to enforce broad water pollution standards, forcing the agency to be more specific in its regulatory approach.

 The case, City and County of San Francisco v. EPA, centered around San Francisco’s wastewater treatment facilities' discharge into the Pacific Ocean. Under the previous EPA permits, the city was required to meet general water quality standards, with local officials responsible for determining the exact measures to ensure compliance. However, the Court's conservative majority disagreed with this model. Justice Samuel Alito, writing for the Court, argued that the EPA overstepped its authority by placing the burden of compliance measures on local governments and entities, while also holding them accountable for the overall water quality. According to Alito, the EPA’s role is to set clear, enforceable pollution limits, not to leave interpretation up to cities and businesses.

 This decision has sparked considerable debate. Industry groups and local governments have lauded the ruling, claiming it offers much-needed clarity and prevents unpredictable enforcement actions. They argue that the previous system led to legal uncertainty, exposing permit holders to potential penalties without clear guidance. On the other hand, environmental advocates see the ruling as a setback for pollution control. They warn that limiting the EPA’s flexibility will make it harder to address pollution and protect public health. In her dissent, Justice Barrett expressed concern that this decision weakens the EPA’s ability to safeguard water quality and could reverse decades of progress in pollution control.

 The ruling extends beyond San Francisco and poses broader implications for NPDES permittees nationwide. Many predict that it will create significant uncertainty for wastewater discharge regulations, as the EPA's adaptive, science-driven approach to water quality standards is now in question. Many municipalities and industries rely on flexible permitting systems, which are now at risk of legal challenges.

 In the aftermath of the ruling, the EPA will need to adjust its regulatory framework, and state agencies may face pressure to fill the gaps left by the Court’s decision, especially with the changes facing EPA under the Trump administration. The ruling sets the stage for more legal battles over the scope of federal environmental oversight. While this marks a setback for those advocating for stricter environmental controls, it is a significant win for industries and local governments seeking more stability and clarity in their regulatory environment.