The Supreme Court's decision is the latest in which conservative justices have reined in pollution control efforts.

But over the past 50 years, some places have occasionally run afoul of the act. In San Francisco, the wastewater system discharges a mix of sewage and stormwater into the bay during major storms, often causing bacteria levels to exceed EPA regulatory standards .

On March 4, 2025, the U.S. Supreme Court issued a 5-4 decision in City and County of San Francisco v. Environmental Protection Agency, narrowing the Environmental Protection Agency’s (EPA) authority under the Clean Water Act (CWA) to impose outcome-based permit conditions—termed “end-result” requirements by the Court—on entities discharging pollutants into U.