Last week, the U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers announced a proposed rule to modify the definition of “Waters of the United States” (WOTUS) under the Clean Water Act. This definition has been a topic of debate for decades, and determines the ways in which wetlands and waterways are monitored and regulated.
After a comment period including nine public listening sessions, the Administration’s latest definition of WOTUS includes revisions that define and add certain terms, narrow the scope of jurisdictional wetlands, and reinforce state and tribal decision-making authority. The update redefines the terms “relatively permanent,” “continuous surface connection,” and “tributary;” articulates exclusions for ditches, converted cropland, and waste treatment systems; adds an additional exclusion for groundwater; and adds local terminology such as “wet season” to define WOTUS for respective locations.
Importantly, the rule exempts from the definition of WOTUS “all components of a waste treatment system designed to meet the requirements of the Clean Water Act, including lagoons and treatment ponds (such as settling or cooling ponds), designed to either convey or retain, concentrate, settle, reduce, or remove pollutants, either actively or passively, from wastewater prior to discharge (or eliminating any such discharge).”
The WateReuse Association will continue assessing the rule in full and developing a comment to submit for the public record. All public comments can be submitted here until January 5, 2026. | 
