EPA and the Corps Issue Revised Definition of “Waters of the US,” Incorporating Both Jurisdictional Tests from Rapanos

Originally published in the January/February 2023 issue of Bench & Bar of Minnesota Environmental Law Update, Minnesota State Bar Association.

On December 30, 2022, the U.S. Environmental Protection Agency (EPA) and the Army Corps of Engineers issued a final rule defining “waters of the United States” (WOTUS). Revised Definition of “Waters of the United States” (33 CFR Pt. 328 & 40 CFR Pt. 120), ___ Fed, Reg. ___ (2022). The definition of WOTUS is significant because it prescribes the reach of federal jurisdiction under the Clean Water Act (CWA), including the NPDES and 404 permit programs. Recall that a set of 1986 rules defining WOTUS had been subject to numerous fractured interpretations by the Supreme Court of the United States, including the court’s decision in Rapanos v. United States, 547 U.S. 715 (2006). In that case Justice Scalia, in a plurality opinion, articulated a jurisdictional test that the CWA extends only to waters that are “relatively permanent, standing or continuously flowing” or to wetlands that are immediately adjacent to such waters. But Justice Kennedy, in a partially concurring opinion, said federal “jurisdiction over wetlands depends upon the existence of a significant nexus between the wetlands in question and navigable waters in the traditional sense.”

EPA during the Obama era adopted a new definition of WOTUS, incorporating the more broad “significant nexus” approach of Justice Kennedy in Rapanos. That definition was repealed by the Trump EPA and replaced by the Navigable Waters Protection Rule (NWPR), which found CWA jurisdiction primarily under Justice Scalia’s more narrow “relatively permanent” standard. In 2021, federal district courts in both Arizona and New Mexico vacated the NWPR. Subsequently, EPA and the Corps announced that they would stop implementing NWPR and rely on the 1986 rule, and, in December 2021, the agencies issued an interim rule defining WOTUS. 86 Fed. Reg. 69372 (Dec. 7, 2021).

The agencies describe the final rule issued on December 30th as a return to a “reasonable and familiar framework founded on the pre-2015 definition [of WOTUS] with updates to reflect existing Supreme Court decisions, the latest science, and the agencies’ technical expertise.” Notably the rule codifies aspects of both the “relatively permanent” and “significant nexus” tests from Rapanos.

 In short, the rule defines WOTUS to include:

• Traditional navigable waters, interstate waters, the territorial seas, and their adjacent wetlands;
• Most impoundments of WOTUS;
• Tributaries to traditional navigable waters, interstate waters, the territorial seas, and impoundments that meet either the relatively permanent standard or the significant nexus standard;
• Wetlands adjacent to impoundments and tributaries, that meet either the relatively permanent standard or the significant nexus standard; and
• Other intrastate lakes and ponds, streams, or wetlands that meet either the relatively permanent standard or the significant nexus standard.

The new rule includes eight exceptions to the WOTUS definition, including the two exceptions codified in the 1986 rule (waste treatment systems and prior converted cropland) and six other exceptions that the agencies have applied by practice: ditches, artificially irrigated areas, artificial lakes or ponds created by excavating or diking dry land to collect and retain water, artificial reflecting or swimming pools or other small ornamental bodies of water, waterfilled depressions created in dry land incidental to construction activity, and swales and erosional features (e.g., gullies, small washes) characterized by low volume, infrequent, or short duration flow.

Notably, the agencies issued the new rule as the U.S. Supreme Court is set to issue a decision in Sackett v. EPA, which is likely to address the CWA jurisdictional standard for wetlands.