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Clean Water Act

Biden Administration Finalizes New WOTUS Definition for the New Year

The EPA and Army Corps have finalized a revised definition of "waters of the United States," which defines the scope of federal regulatory jurisdiction under the Clean Water Act.


Today the U.S. Environmental Protection Agency and U.S. Army Corps of Engineers released their released a final rule revising the federal definition of "waters of the United States"(aka "WOTUS"), which defines the scope of federal regulation under the Clean Water Act. This rule is less expansive than the WOTUS definition promulgated by the Obama Administration, but more expansive than adopted by the Trump Administration.

The CWA prohibits the discharge of pollutants in the navigable waters of the United States. The CWA further defines "navigable waters" as "the waters of the United States." This new rule, in turn, adopts a regulatory definition of "waters of the United States."

The new rule covers all waters and wetlands with a continuous surface connections with navigable waters, as well as those waters and wetlands which, "either alone or in combination with similarly situated waters in the region, significantly affect the chemical, physical, or biological integrity" of navigable waters. The legal question is whether this definition extends the agencies' authority beyond that which is auhtorized by the CWA, or extends beyond the scope of Congress' power under the Commerce Clause, which (combined with the Necessary and Proper Clause) allows the federal government to regulate that which "subtantially affects" interstate commerce.

The EPA and Army Corps will argue that those waters and wetlands which "significantly affect the chemical, physical, or biological integrity" have a significant affect on interstate commerce. At least as applied to some lands, I expect this assertion to be challenged in federal court. However much it make sense to the agencies to regulate all waters with a significant hydrological connection to navigable waters, the federal governent's regulatory authority is not defined in such terms.

This is the third WOTUS definition issued in the past eight years, and the third attempt to adopt a definition that is consistent with the Surpeme Court's SWANCC and Rapanos decisions, each of which concluded the two agencies had adopted unduly expansive interpretations of their own jurisdiction. The rule also purports to provide additional guidance as to the extent to which (in view of the two agencies) wetlands near or adjacent to navigable waters are subject to regulation as part of the "waters of the United States," a question currently before the Court in Sackett v. EPA.

The rule will take effect 60 days after it is published in the Federal Register.