Katelyn McGruder

Associate Editor

Loyola University Chicago School of Law, JD 2026

 

In a landmark decision issued on March 4, 2025, the U.S. Supreme Court ruled in City and County of San Francisco v. Environmental Protection Agency that the U.S. Environmental Protection Agency (EPA) cannot impose certain types of permit requirements on entities discharging pollutants into U.S. waters. The case, which centered on the Clean Water Act (CWA), has significant implications for how the federal government regulates water pollution and protects water quality. The decision, which saw a 5-4 vote, limits the EPA’s ability to enforce “end-result” requirements in permits, raising concerns about the future of water quality standards and environmental protection.

Facts of the case

The case arose from a dispute over the National Pollutant Discharge Elimination System (NPDES) permit issued to San Francisco for its Oceanside wastewater treatment facility. The facility processes both wastewater and stormwater, and during heavy rainfall, it can discharge untreated water, including raw sewage, into the Pacific Ocean. In 2019, the EPA renewed San Francisco’s permit but added two “end-result” requirements. The first prohibited the facility from discharging any pollutants that contribute to a violation of water quality standards in the receiving waters. The second required that the facility not create pollution, contamination, or a nuisance as defined by California law.

San Francisco challenged these requirements, arguing that they exceeded the EPA’s authority under the Clean Water Act. The city contended that the CWA does not allow the EPA to impose permit conditions that hold permittees responsible for the quality of the receiving waters, rather than specifying what actions the permittee must take to prevent pollution. The Ninth Circuit Court of Appeals upheld the EPA’s authority to include these requirements, but the Supreme Court reversed that decision, siding with San Francisco.

The Supreme Court’s decision

San Francisco argued that the CWA does not authorize the EPA to impose end-result requirements, which condition compliance on the quality of the receiving waters rather than specifying what actions the permittee must take. The city contended that such requirements would undermine the permit shield, exposing permittees to liability even if they followed all specific permit conditions. San Francisco also argued that end-result requirements would create unfairness in cases where multiple dischargers contribute to water quality violations, making it difficult to allocate responsibility.

The EPA, on the other hand, maintained that Section 1311(b)(1)(C) of the CWA authorizes it to impose “any more stringent limitation” necessary to meet water quality standards, including end-result requirements. The agency argued that end-result requirements are necessary in situations where it lacks the information to develop more specific limitations, such as in cases involving complex combined sewer systems. The EPA also contended that end-result requirements are consistent with the CWA’s goal of protecting water quality and ensuring that discharges do not harm the environment.

In a majority opinion written by Justice Samuel Alito, the Court held that Section 1311(b)(1)(C) of the Clean Water Act does not authorize the EPA to impose “end-result” requirements in NPDES permits. The Court reasoned that the CWA requires the EPA to set specific rules and limitations that permittees must follow to achieve water quality goals, rather than simply mandating that permittees ensure the end result of meeting water quality standards.

The Court emphasized that the CWA’s permit shield provision, which protects permittees from liability if they comply with their permit terms, would be undermined if the EPA could impose end-result requirements. Such requirements would leave permittees vulnerable to penalties even if they followed all specific permit conditions, simply because the receiving waters failed to meet quality standards.

Justice Amy Coney Barrett, joined by Justices Sonia Sotomayor, Elena Kagan, and Ketanji Brown Jackson, dissented in part. Barrett argued that the majority’s interpretation of the CWA was too narrow and that the EPA’s end-result requirements were consistent with the statute’s text and purpose.

A brief history of the Clean Water Act

The Clean Water Act, enacted in 1972 by President Nixon, is the primary federal law governing water pollution in the United States. It aims to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. The CWA established the NPDES permit system, which regulates discharges of pollutants into U.S. waters. Under the CWA, entities must obtain permits that set limits on the types and amounts of pollutants they can discharge.

The CWA marked a significant shift from the previous approach to water pollution regulation, which relied on abatement actions after pollution occurred. Instead, the CWA focuses on preventing pollution by imposing direct restrictions on dischargers. The Act also requires states to set water quality standards and provides for federal oversight to ensure those standards are met.

The dangers of this decision

The Supreme Court’s decision in San Francisco v. EPA poses several risks to water quality and environmental protection. By limiting the EPA’s ability to impose end-result requirements, the decision may make it harder to enforce water quality standards. Without these requirements, permittees could discharge pollutants that contribute to water quality violations, as long as they comply with specific permit conditions.

Additionally, the decision may hinder the EPA’s ability to regulate complex pollution sources, such as combined sewer systems, where it is difficult to predict the impact of discharges on water quality. Without end-result requirements, the EPA may struggle to ensure that these systems do not harm the environment.

The decision also highlights the broader dangers of the Trump administration’s deregulatory agenda. By rolling back environmental protections and limiting the EPA’s authority, the administration is undermining the federal government’s ability to address pressing environmental challenges. This trend poses significant risks to the environment and public health, and it underscores the need for continued vigilance and advocacy to protect the nation’s natural resources.

Conclusion

The Supreme Court’s decision in San Francisco v. EPA represents a significant shift in the interpretation of the Clean Water Act and could have far-reaching consequences for water quality and environmental protection. By limiting the EPA’s ability to impose end-result requirements, the decision may weaken the enforcement of water quality standards and create challenges for regulating complex pollution sources. As the implications of the decision unfold, it will be crucial for policymakers, environmental advocates, and regulated entities to navigate the changing regulatory landscape and work toward solutions that protect the nation’s waters.