The Supreme Court has issued a preliminary ruling in *City and County of San Francisco v. Environmental Protection Agency*, a case that addresses critical questions about Clean Water Act permit requirements and federal environmental oversight. The case, numbered 23-753, was argued before the high court on Oct. 16, 2024, and represents a significant dispute between municipal authorities and federal regulators over water pollution control.

The case centers on the National Pollutant Discharge Elimination System (NPDES), a cornerstone of the Clean Water Act's regulatory framework that governs how pollutants can be discharged into U.S. waters. Under the Clean Water Act, the Environmental Protection Agency and authorized state agencies issue permits that impose requirements on entities seeking to discharge pollutants into waters of the United States.

The NPDES system makes it unlawful to discharge pollutants into covered bodies of water unless authorized by a permit. The preliminary ruling addresses key questions about federal oversight of these permits and the permit shield provision that protects entities complying with permit terms.

This preliminary decision could have significant implications for municipal wastewater management and federal environmental enforcement practices nationwide, though the final impact will depend on the Court's final published opinion. Non-compliance with permit limitations can result in civil penalties and criminal prosecution under the Clean Water Act.

*Note: This report is based on a preliminary print of the Supreme Court decision that is marked 'Proof Pending Publication' and remains subject to revision before final publication.*