"Waters of the United States" Reset to Pre-2015 Definition

Water cascading over a very short wall in a dam

October 11, 2021

U.S. District Court vacates Trump administration rule, EPA & USACE return to pre-2015 WOTUS policies

In June, the U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers (USACE) announced their intention to revise the definition of "waters of the United States" (WOTUS), which determines the federal jurisdiction of the Clean Water Act (CWA) to regulate pollutant discharges. The purview of the CWA was expanded by the Obama administration in 2015 and subsequently narrowed by the Trump administration's Navigable Waters Protection Rule (NWPR) in 2020. The Biden administration announced its commitment "to establishing a durable definition of 'waters of the United States'" but would need to rescind the Trump administration's rule before publishing its own.

Then, on August 30th, the U.S. District Court for Arizona vacated and remanded the NWPR as part of its decision in the case of Pascua Yaqui Tribe v. U.S. Environmental Protection Agency. While a legal question remains on whether or not a district court can vacate a federal rule, EPA has responded that "in light of this order, the agencies have halted implementation of the [NWPR] and are interpreting 'waters of the United States' consistent with the pre-2015 regulatory regime until further notice." Reverting to the pre-2015 Obama-era rules means returning to policies from the 1980s and 1990s that have been subject to decades of legal battles, including a series of U.S. Supreme Court decisions from the 2000s (e.g., Rapanos v. United States and Solid Waste Agency of Northern Cook County v. United States).

The Biden administration still intends to develop their own definition of WOTUS, with the EPA statement reiterating their commitment to "move forward with the rulemakings announced on June 9, 2021, in order to better protect our nation's vital water resources," and craft a "durable definition of 'waters of the United States' that is informed by diverse perspectives and based on an inclusive foundation." EPA held a series of public meetings in August with written recommendations accepted by September 3, 2021, on how best to create and implement the new definition of WOTUS.

How Exponent Can Help

Exponent's environmental scientists and engineers have extensive experience with the CWA and its jurisdiction. We use this experience to assist our clients whose permits and operations are expected to be affected by changes to the definition of WOTUS. With our regulatory experience and interdisciplinary expertise, in wetland ecology, botany, aquatic and terrestrial biology, hydrology, chemistry, ecotoxicology, soil science, environmental and civil engineering, we can evaluate the connections between navigable waters and adjacent waterbodies; assess interactions between groundwater and surface water (an issue in the Co of Maui v. Hawaii Wildlife Fund case); evaluate data characterizing water and sediment quality; prepare permit applications and assist in the negotiation of permit limits and conditions; and develop monitoring plans and implementation strategies.