In the closely watched case, City and County of San Francisco v. Environmental Protection Agency, the Supreme Court held in a 5-4 decision that Section 1311(b)(1)(C) of the Clean Water Act (CWA) does not authorize the Environmental Protection Agency (EPA) to condition compliance with its National Pollutant Discharge Elimination System (NPDES) permits on the quality of the receiving waters. The ruling is expected to significantly impact wastewater treatment facilities nationwide by narrowing the scope of EPA enforcement authority.
As reported in our November 2024 edition, the CWA is a comprehensive water quality statute intended to protect the "integrity of the Nation's waters." 33 U.S.C. § 1251(a). While the Act generally prohibits the discharge of pollutants, it provides a permitting mechanism under the NPDES program, allowing discharges when they conform to specific limitations set forth in the permit. 33 U.S.C. § 1342(a)(1).
At issue was San Francisco's challenge to a 2019 NPDES, which included two contested provisions: (1) a prohibition on discharges that "contribute[s] to a violation of any applicable water quality standard," and (2) a ban on any discharge that "create[s] pollution, contamination, or nuisance" as defined under the statute. The city argued that these provisions improperly tethered compliance to the overall condition of the receiving waters—something potentially outside a permittee's control—rather than to the specific characteristics of the effluent (discharge) itself.
The Ninth Circuit upheld the EPA's position, interpreting the CWA as permitting broad regulatory authority, including the ability to enforce narrative water quality standards beyond numeric effluent limits. The Supreme Court granted review to resolve the tension between the EPA's interpretation and the statutory text.
Justice Alito delivered the Court's opinion. In Part II, joined by all except Justice Gorsuch, the Court acknowledged that § 1311(b)(1)(C) permits the EPA to impose "more stringent limitations" to meet water quality standards, and that such limitations need not always take the form of quantitative effluent restrictions. The Court recognized the legitimacy of narrative conditions, such as best practices, which may fall outside traditional "effluent limitation" definitions. However, in Part III of the opinion—joined only by Chief Justice Roberts and Justices Thomas, Kavanaugh, and Gorsuch—the majority held that § 1311(b)(1)(C) does not authorize the EPA to make compliance contingent upon the actual condition of the receiving waters. The majority reasoned:
- The statute authorizes limitations aimed at achieving certain water quality outcomes but does not allow the EPA to penalize permittees based on ambient water conditions.
- Earlier legislative frameworks did impose liability based on receiving water quality, and the absence of similar provisions in the current CWA reflects a conscious legislative choice.
- The "permit shield" provision, 33 U.S.C. § 1342(k), and the lack of statutory guidance on shared water bodies with multiple dischargers, further supported limiting EPA's authority in this context.
Justice Barrett, dissenting from Part III and joined by Justices Sotomayor, Kagan, and Jackson, criticized the majority's conclusion as inconsistent with the purpose of § 1311(b)(1)(C). She emphasized that the provision's express function is to ensure discharges comply with state water quality standards. Barrett warned that removing this tool from the EPA's regulatory and enforcement toolbox could undermine its ability to issue enforceable permits that satisfy statutory requirements, ultimately complicating compliance for municipalities and businesses alike.
This ruling substantially curtails the EPA's ability to use receiving water quality as a direct basis for enforcement under the NPDES program. While the agency retains authority to include narrative and best-practice conditions in permits, it may no longer condition permit compliance on downstream water quality—particularly when influenced by multiple dischargers or other environmental factors.
For wastewater treatment operators and other permittees, the decision reduces exposure to civil and criminal liability based on factors beyond their control. At the same time, the ruling raises questions about how federal and state regulators can ensure attainment of water quality standards in complex, multi-source watersheds.
Takeaways:
- Narrowing of EPA Enforcement Authority: The Court limits the EPA's ability to condition permit compliance on receiving water quality under § 1311(b)(1)(C) of the CWA.
- Increased Certainty for Permittees: Facilities may face reduced legal risk for water quality outcomes not solely attributable to their own discharges.
- Enforcement Shift Likely: The EPA may need to revise its permitting practices and enforcement strategies in light of the Court's interpretation.
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