Waters of the United States: EPA and Corps Issue Guidance and Preview Revisions to Rule

Originally published in the May/June 2025 issue of Bench & Bar of Minnesota Environmental Law Update, Minnesota State Bar Association.

On March 12, 2025, the U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers (Corps) announced that the agencies would “move quickly” to revise their matching regulatory definitions of “Waters of the United States” (or, WOTUS). EPA cited the Supreme Court’s decision in Sackett v. EPA, 598 U.S. 651 (2023), as the reason for its action and stated that a revised definition would “follow[] the law, reduce[] red-tape, cut[] overall permitting costs, and lower[] the cost of doing business. . . .” On the same day, EPA released a memorandum “concerning the proper implementation of ‘continuous surface connection’ under the definition of ‘Waters of the United States’ under the Clean Water Act” (Guidance). EPA also issued a pre-publication notice concerning public input on WOTUS issues: “WOTUS Notice: The Final Response to SCOTUS; Establishment of a Public Docket; Request for Recommendations.”

The Guidance is effective immediately and directs agencies to apply a narrow interpretation of the Supreme Court’s Sackett test for determining which wetlands are subject to federal jurisdiction under the Clean Water Act (CWA). EPA and the Corps plan to engage in rule-making regarding the WOTUS definition.

Background: The CWA, including the Section 404 and NPDES permitting programs, only apply to discharges to “navigable waters,” which the CWA defines simply as “Waters of the United States” (i.e., WOTUS). The federal agencies charged with administering the Section 404 and NPDES program – the Corps and EPA, respectively – have adopted numerous regulatory definitions of WOTUS over the last 50 years, varying in scope to reflect Supreme Court decisions and the priorities of new federal administrations. While there has been relatively little debate about whether WOTUS includes oceans, rivers and most lakes, the reach of the CWA over wetlands has been highly controversial.

In Rapanos v. United States, 547 U.S. 715 (2006), Justice Scalia, in a plurality opinion, held that WOTUS includes only those wetlands with a “continuous surface connection” to traditional WOTUS, such as rivers and lakes. Meanwhile, Justice Kennedy, in a partially concurring opinion, opined that the CWA more broadly covers any wetland where there is a “significant nexus” between the wetland and a traditional WOTUS. Based on these dueling interpretations, EPA and the Corps, in January 2023, published a definition of WOTUS that incorporated aspects of both the “continuous surface connection” and “significant nexus” tests from Rapanos. 88 Fed. Reg. 3004 (1-18-2023). Notably, in the preamble to this rule, the agencies wrote that a “continuous surface connection” between a wetland and a traditional WOTUS could be found if the two are connected “by a discrete feature like a non-jurisdictional ditch, swale, pipe, or culvert.”

Five months later, in May 2023, the Supreme Court in Sackett rejected the “significant nexus” test, establishing a two-part jurisdictional for finding a wetland jurisdictional, directly based on Justice Scalia’s plurality decision in Rapanos:

• The adjacent body of water must constitute a WOTUS (i.e., “a relatively permanent body of water connected to traditional interstate navigable waters”); and
• The wetland must have a “continuous surface connection” with that water, “making it difficult to determine where the water ends and the wetland begins.”

In response, EPA and the Corps published a final conforming rule – which, due to litigation, only applies in 24 states – revising their WOTUS definition to remove references to “significant nexus.” 88 Fed. Reg. 61964 (9-8-2023). The agencies did not amend their guidance on using “discrete features” to find a “continuous surface connection.” 

Guidance: The Guidance is “effective immediately” and discusses how EPA and Corps staff should implement the definition of WOTUS. In addition to affirming the two-part “continuous surface connection” test from Sackett, the guidance states that staff may not use a “discrete feature” as the basis for the “continuous surface connection” necessary to assert jurisdiction over the wetland. This former interpretation, the guidance explains, was “in tension with the pre-2015 regime and Sackett.” However, recognizing that there may be circumstances where drawing the line on what is and is not a “continuous surface connection” may be tricky, the guidance indicates that the agencies will “work to resolve these scenarios on a case-by-case basis and provide further clarity when appropriate to guide future implementation.”

Notice: The Notice outlines a process to gather stakeholder input to inform future rule-making and administrative actions regarding WOTUS. Specifically, the agencies are seeking feedback on the following topics:

• The scope of “relatively permanent” waters and to what features this phrase applies;
• The scope of “continuous surface connection” and to which features this phrase applies; and,
• The scope of jurisdictional ditches.

The Notice does not identify an estimated timeframe for rule-making.

For more information, contact Haley Waller Pitts and Jeremy Greenhouse.