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U.S. Supreme Court Narrows Scope of EPA Authority Under the Clean Water Act in Sackett v. Environmental Protection Agency

By Kerry Shapiro and Daniel Quinley

On May 25, 2023, the United States Supreme Court issued its ruling in Sackett v. Environmental Protection Agency, narrowing the scope of the Environmental Protection Agency’s (EPA) regulatory authority under the Clean Water Act (CWA). The court held that the EPA’s authority under the CWA extends only to wetlands and permanent bodies of water with a “continuous surface connection” to “traditional interstate navigable waters.”

Sackett addressed the scope of EPA’s authority to regulate wetlands under the CWA, which generally prohibits discharging pollutants into “the waters of the United States.” 33 U.S.C. §1362(7). The Sacketts petitioned the Supreme Court for review of the Ninth Circuit’s decision upholding the scope of EPA’s authority. The Sacketts had purchased a lot upon which they planned to build a home and began backfilling this lot with dirt in preparation. However, the EPA sought to exercise jurisdiction, based on the assertion that the lot contained wetlands and backfilling it violated the CWA. At issue for the Court was whether these wetlands were, in fact, “waters of the United States” subject to regulation under the CWA.

The Supreme Court’s decision resolves ambiguity in the CWA over the meaning of “waters of the United States” within the context of the statute. Justice Alito, in his opinion, described the current confusion stemming from the ambiguity of the CWA’s language: “[W]hat does that phrase mean? Does the term encompass any backyard that is soggy enough for some minimum period of time? Does it reach ‘mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, [or] playa lakes?’ How about ditches, swimming pools, and puddles?”

This jurisdictional ambiguity has existed, in part, since the plurality split in the Court’s decision in Rapanos v. United States (2006) 547 U.S. 715, which articulated two tests for lower courts to use in determining whether the CWA applies: Justice Scalia’s bright-line rule, covering only wetlands next to “relatively permanent, standing or continuously flowing bodies of water”; and Justice Kennedy’s broader interpretation, protecting wetlands that were part of a “significant nexus” with a navigable body of water.

In the present case, the Idaho District Court applied Justice Kennedy’s “significant nexus” test to the Sacketts’ property in upholding the EPA’s finding that the property was a wetland regulated by the CWA, a decision affirmed by the Ninth Circuit.

Relying heavily on Justice Scalia’s bright-line rule articulated in Rapanos, the Supreme Court reversed the Ninth Circuit’s decision and concluded that the only waters which are “waters of the United States” and thus protected by the CWA are those with a continuous surface connection to “navigable waters,” like key lakes and rivers that affect interstate commerce. Critically, only those wetlands or waters with surface connections, not underground connections, or wetlands or waterways segregated by man-made barrier, are regulated by the CWA under the Supreme Court’s interpretation.

The Court’s decision provides important guidance regarding future federal regulation of land use, as it is now significantly more difficult for the EPA to assert jurisdiction over private land under the CWA. Moreover, the clear standard established by this decision resolves long-standing ambiguities resulting from the previously dueling regulatory definitions and decisions regarding proper consideration of “waters of the United States.”

It remains to be seen how the Biden administration and the EPA will respond to the ruling, as the EPA likely will have to rewrite some of its regulations as to “waters of the United States” now that Justice Kennedy’s “significant nexus” test has been rejected.

For California, the ruling does not change the State Water Resources Control Board’s attempts to fill the regulatory gap under its “Waters of the State” definition, and related “Procedures for Discharges of Dredged or Fill Material to Waters of the State,” as discussed in prior posts here and here.

Additionally, the Supreme Court’s interpretation of “waters of the United States,” may significantly limit certain uses of jurisdictional waters to initiate Section 7 Consultation under the federal Endangered Species Act (the “small federal handle”). Accordingly, some project proponents may be forced to obtain incidental take coverage under the more onerous – and expensive – Section 10 “incidental take permit” process.

If you have any questions regarding the impact of the Sackett decision on your project, please contact JMBM’s Natural Resource and Mining Group.

Click here for a copy of the Supreme Court’s decision. Sackett v. Environmental Protection Agency

Kerry Shapiro
Kerry Shapiro chairs the Natural Resources & Mining Practice Group at Jeffer Mangels Butler & Mitchell LLP. He has represented the mining, building materials, and other resource industries on mineral extraction and land development projects for more than 25 years. Kerry also serves as General Counsel to the California Construction and Industrial Materials Association (CalCIMA). Contact Kerry at

Daniel Quinley
Daniel Quinley is an environmental and land use lawyer at Jeffer Mangels Butler & Mitchell LLP. He represents clients in complex regulatory, permitting, policy, and litigation arenas. Contact Dan at

JMBM’s Natural Resources & Mining Law Group
Jeffer Mangels Butler & Mitchell LLP has one of California’s leading natural resources and mining law practice groups. The group is comprised of lawyers with over 25 years of practice in law firms, government, and consulting, and provides companies and trade associations with unparalleled counseling, compliance, and litigation services in nearly every area of federal and California natural resources and mining law.