On June 27, 2017, the U.S. Environmental Protection Agency and U.S. Army Corps of Engineers released a proposed rule for publication in the Federal Register
that would rescind the current definition of “waters of the United States” under the Clean Water Act and re-codify the pre-2015 definition utilized by the agencies. The agencies moreover announced that the proposed rule is the first step in a “comprehensive, two-step process intended to review and revise the definition of ‘waters of the United States’ consistent with” President Trump’s February 28, 2017 Executive Order “Restoring the Rule of Law, Federalism, and Economic Growth by Reviewing the ‘Waters of the United States’ Rule.” Once the pre-2015 definition is re-codified, the agencies state that they will pursue a notice and comment rulemaking to conduct a substantive re-evaluation of the definition.
During the second-step re-evaluation, the agencies state that they will develop a new definition that takes “into consideration the principles that Justice Scalia outlined in the Rapanos plurality opinion.” In Rapanos, Justice Scalia authored a plurality opinion that concluded that “waters of the United States” – and therefore the jurisdiction of federal agencies under the Clean Water Act – include only those relatively permanent, standing, or continuously flowing bodies of water. Conversely, Justice Scalia’s plurality opinion stated that water bodies that flow intermittently or ephemerally are not “Waters of the United States.” Moreover, Justice Scalia’s opinion stated that wetlands are not jurisdictional based on a mere hydrologic connection to “waters of the United States.” Instead, for a wetland to be considered jurisdictional, there must be an inherent ambiguity concerning where the jurisdictional water ends and the wetland begins.