EPA & U.S. Army Corps of Engineers revise Waters of the United States (WOTUS) definition

Key Takeaways

On March 12, the U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (Corps) issued a joint memorandum outlining the next steps to revise the “waters of the United States” (WOTUS) definition under the Clean Water Act (CWA). This follows the Supreme Court’s 2023 decision in Sackett v. EPA, which limits the EPA’s regulatory authority over wetlands without a “continuous surface connection” to traditional navigable waters.

The memorandum clarifies that wetlands must have a direct, unbroken surface water connection to qualify as WOTUS. It aims to resolve inconsistencies in previous guidance, ensuring a uniform national approach for jurisdictional determinations and permitting. Additionally, the EPA and Corps will collaborate to reduce red tape, lower permitting costs, and balance environmental protection with economic development.

To engage stakeholders, the agencies released a Federal Register Notice and will host listening sessions to gather input on challenges to implementing the rule.

What is WOTUS?

“Waters of the United States” is a term in the Clean Water Act used to determine which waters fall under federal jurisdiction. The CWA prohibits the discharge of pollutants into “navigable waters,” defined as “waters of the United States, including the territorial seas.” However, the Act does not further specify the definition of WOTUS, leaving the EPA and the Corps responsible for interpreting it through regulations.

Since the 1980s, the agencies have periodically updated the definition, with major revisions in 2015, 2020, and 2023 through the Clean Water Rule, the Navigable Waters Protection Rule (NWPR), and the January 2023 Rule. The most recent rule used both the “relatively permanent” and “significant nexus” tests to determine jurisdiction, but the Sackett decision invalidated the significant nexus test.

In Sackett v. EPA, the Court ruled that the CWA covers only “relatively permanent, standing or continuously flowing bodies of water” and wetlands that are “indistinguishable” from jurisdictional waters. This significantly narrowed federal jurisdiction under the CWA.

How does this impact counties?

Counties are responsible for essential infrastructure, including public safety water conveyances, municipal separate stormwater sewer systems (MS4s), green infrastructure projects, water reuse systems, and emergency management systems. Whether a body of water is classified as WOTUS can determine whether counties must obtain federal permits for maintenance or construction projects. Counties will have the opportunity to share input on the implementation of the rule.

Counties urge federal agencies to maintain clear and consistent definitions to avoid unnecessary confusion and costly delays. NACo will continue working with federal partners to promote pragmatic WOTUS definitions that protect water quality while supporting counties' health, safety, and infrastructure responsibilities.

Resources

• NACo Regulatory Analysis – The Conforming Rule: The Waters of the United States
• EPA Waters of the United States website
• EPA and Corps Joint Memo
• EPA Administrator WOTUS Rule Press Release