SCOTUS Agrees to Review EPA’s Authority to Issue Narrative Effluent Limitations under the Clean Water Act

Mon Jul 1st, On Environmental Law, by

SCOTUS Grants City and County of San Francisco’s Petition for Writ of Mandate

On May 28, 2024 the U.S. Supreme Court agreed to take up the issue of whether the United States Environmental Protection Agency (“EPA”) has authority to establish narrative effluent limitations under the Clean Water Act (“CWA”). After the Ninth Circuit answered this question affirmatively in favor of the EPA, the City and County of San Francisco (“San Francisco”) submitted a Petition for Writ of Certiorari (“Petition”) to the Supreme Court, seeking reversal.

San Francisco’s NPDES Permit

The legal issue arises from certain requirements within a permit the EPA issued to San Francisco under the National Pollution Discharge Elimination System (“NPDES”), a federal program authorized by the CWA to regulate point source pollution into U.S. waters. NPDES permits allow permit-holders like San Francisco to legally discharge specified amounts of a pollutant into waters of the United States. When a permit-holder exceeds its permitted effluent discharge limits, that permittee is subject to a CWA enforcement action.

San Francisco needs an NPDES permit to discharge pollutants into U.S. waters because it uses a combined sewer system to treat the city’s wastewater (which includes both domestic and industrial sewage as well as rainwater runoff). Combined sewer systems are designed to collect and treat all wastewater before it gets released into an adjacent water body (which, in San Francisco’s case, is the Pacific Ocean). During normal weather conditions, the city’s system is able to treat all collected wastewater prior to ocean release. However, because rainwater runoff is also directed to the treatment system to remove pollutants and oils that are picked up from city surfaces, during heavy rainfall periods the amount of rainwater runoff entering the system can exceed the system’s treatment capacity. To avoid sewage backups within the city, the system releases “combined sewer overflows” (i.e., the wastewater mix of raw sewage and polluted rainwater runoff) directly into the ocean without treating it. San Francisco is authorized by its NPDES permit to legally discharge limited amounts of combined sewer overflows from its combined sewer system into the Pacific Ocean during heavy rainfall periods.  

San Francisco Disputes its NPDES Permit Limitations

In the recent Ninth Circuit case, San Francisco argued that two specific discharge limitations in its NDPES permit are too “generic” under the CWA for the city to comply with. It contended these limitations, which are expressed as narrative effluent limitations measured by the receiving water’s overall quality rather than as numeric limits on the amount of pollution San Francisco can discharge, unfairly judge San Francisco’s compliance based on the Pacific Ocean’s water quality over which the city has virtually no control. It also argues that narrative limitations make it impossible for the city to ensure its discharges comply with the applicable water quality standards.

The first narrative prohibition challenged by San Francisco states in Section V of the permit that “[d]ischarge shall not cause or contribute to a violation of any applicable water quality standard . . . for receiving waters adopted by the Regional Water Board, State Water Resources Control Board (State Water Board), or U.S. EPA.” The second challenged limitation states in Attachment G of the permit that  “[n]either the treatment nor the discharge of pollutants shall create pollution, contamination, or nuisance as defined by California Water Code section 13050.”

San Francisco argues that a determination of whether the legal standards in these two provisions (Section V’s water quality standards and Attachment G’s “pollution,” “contamination,” and “nuisance” standards) are met is based on the Pacific Ocean’s overall water quality and such an evaluation is only conducted after the city has already discharged pollutants and thus after it is too late for the city to bring itself into compliance. For example, California Water Code section 13050 provides that a finding of “pollution,” “contamination,” or “nuisance” depends on the overall condition of the receiving waters rather than on the amount of pollutants an individual party has contributed. San Francisco requested that the EPA instead either set specific limits on the quantities of pollutants San Francisco is allowed to discharge and/or prescribe management practices the city must implement. It argued that only concrete directives can assure San Francisco that as long as it complies with the directives in its permit it will not be vulnerable to government enforcement. San Francisco also contends that it needs specific limitations to budget and plan for future improvements to its stormwater treatment system that ensure adequate system reliability and capacity. 

The Ninth Circuit disagreed with San Francisco, finding that the narrative provisions operated as a critical “backstop” to ensure the Pacific Ocean’s water quality was protected if the other effluent limitations in San Francisco’s NPDES permit did not by themselves achieve the water quality standards. It agreed with the EPA that San Francisco’s challenged NPDES permit limitations are adequately defined by statutory law and federal agency plans and orders.

The Ninth Circuit also rejected San Francisco’s argument that finding in favor of the EPA would contradict opinions from the Second Circuit and U.S. Supreme Court which both held the EPA was required under the CWA to establish specific discharge limitations. Petitioners in those cases were concerned that the water bodies receiving discharges were not meeting the narrative water quality standards and thus urged the EPA to issue specific effluent limitations to improve the receiving water quality. San Francisco argued the cases equally support its position that the EPA must issue specific numeric discharge limitations. The Ninth Circuit explained that the Second Circuit and Supreme Court opinions were inapposite to San Francisco’s case in part because they each required specific effluent limitations to assure water quality standards were met, rather than to allow parties like San Francisco to shield themselves from liability when water quality standards are not met.

Supreme Court Review

In its briefing submitted to the U.S. Supreme Court, San Francisco renewed the arguments it made before the Ninth Circuit. As it stated in its Reply to EPA’s Opposition, “[t]he Generic Prohibitions make compliance with the CWA elusive, because a waterbody’s ability to meet water quality standards at any time depends on pollutants that all sources—not just San Francisco—contribute. San Francisco consequently lacks advanced notice of how much it must control its discharges without violating the Generic Prohibitions.” The specific legal question presented for the Supreme Court’s review, which the Court has agreed to decide, is whether the CWA authorizes the EPA to set the narrative effluent limitations with which San Francisco takes issue.

Given the Supreme Court’s recent majority opinion in Sackett v. EPA which narrowed the EPA’s regulatory authority under the CWA, the Court majority will most likely rule similarly in this case. Last year’s Sackett majority opinion took a textualist approach in interpreting the meaning of “wetlands” under the CWA and crafted a narrower definition that will exclude nearly half of the wetland areas that were previously protected under the CWA in favor of a private landowner seeking to develop on sensitive wetlands habitat. The Court majority described the CWA as “a potent weapon” that imposes “‘crushing’ consequences ‘even for inadvertent violations,” signaling that if again faced with the decision to either curtail local property rights or regulatory authority to protect waters of the United States, it will choose the latter.

The Court may also agree with San Francisco that the Ninth Circuit opinion has created a circuit split from the Second Circuit and deviates from a U.S. Supreme Court opinion.  Although the Ninth Circuit found these opinions inapposite to San Francisco’s case because they required specific discharge limitations in permits to help ensure compliance with water quality standards (rather than escape liability for them), the Supreme Court may adopt San Francisco’s interpretation of these cases as holding that the EPA may only prescribe specific effluent limitations regardless of environmental motivations or consequences. Such an interpretation would align with the Supreme Court majority’s intolerance for environmental regulatory ambiguity in Sackett.

If the Supreme Court overturns the Ninth Circuit holding and finds the challenged permit provisions are indeed unlawful, this will affect all municipalities in the country holding NPDES permits with similar provisions, which are many. As the Ninth Circuit opinion explained, the EPA frequently includes permit terms similar to those of Section V in other NPDES permits for municipalities operating combined sewer systems, and the Regional Water Board has also included a provision identical to that of Attachment G in nearly all individual NPDES permits issued since 1993. Removing assurances from all NPDES permits that water quality standards for U.S. waters are met, which the EPA warns serve as a backstop if other numeric permit terms do not alone achieve acceptable water quality, could result in further-degraded quality of U.S. waters.

Amicus Briefing

This legal dispute reflects a broader debate on the need for precise regulatory requirements to protect water quality. The National Association of Clean Water Agencies, which represents public wastewater and stormwater agencies nationwide, has joined an amici curiae brief in support of San Francisco’s position, advocating for specific effluent discharge requirements to avoid ambiguity in permit compliance. It emphasizes San Francisco’s point that permittees need a clear understanding of their compliance obligations in order to efficiently use public funds needed to plan and pay for maintaining and upgrading the nation’s wastewater and stormwater infrastructure. In addition, fifteen industry-centered associations that together represent nearly every business sector in the U.S., including the National Mining Association, the American Petroleum Institute, and the National Pork Producers Council, have jointly submitted an amici curiae brief in support of San Francisco’s arguments for overturning the Ninth Circuit holding.


The Supreme Court’s decision in this case is one more case the Court will use to shape the interpretation and enforcement of the Clean Water Act and the establishment of enforceable pollution standards, and, potentially, environmental regulations across the United States.

The case is City and County of San Francisco v. U.S. Environmental Protection Agency, case number 23-753, in the Supreme Court of the United States.

The California environmental lawyers at Bick Law LLP will continue to monitor this case and will post updates as they arise.

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