On February 14, 2019, the U.S. Environmental Protection Agency (EPA) and the Department of the Army (Army) published for public comment a proposed rule revising the definition of “waters of the United States,” which would establish the scope of federal regulatory authority under the Clean Water Act (CWA). The proposed rule is intended to satisfy the requirements of Executive Order (EO) 13778 that directed the EPA and the Army to review and rescind or replace the 2015 Clean Water Rule (80 FR 37053) and consider interpreting the scope of “waters of the United States” consistent with the Justice Scalia opinion (plurality standard) from Rapanos v. United States (2006). The EO instructed that any new proposed rule shall ensure that the Nation’s navigable waters are kept free from pollution, while at the same time promoting economic growth, minimizing regulatory uncertainty, and showing due regard for the roles of the Congress and the States under the Constitution.
The proposed revised definition outlines six categories of waters that would be considered “waters of the United States” in section (a), including: traditional navigable waters, including the territorial seas; tributaries that contribute perennial or intermittent flow to such waters; certain ditches; certain lakes and ponds; impoundments of otherwise jurisdictional waters; and wetlands adjacent to other jurisdictional waters.
The proposed revised definition also outlines what would not be considered “waters of the United States” in section (b), including: waters not identified in section (a); groundwater; ephemeral features; ditches not included in section (a); prior converted cropland, as defined; certain artificially irrigated areas; certain artificial lakes and ponds; certain water-filled depressions; certain stormwater control features; certain wastewater recycling structures; and waste treatment systems, as defined.
Additionally, the proposed rule provides definitions for key terms used in the regulation in section (c). Some of these are unchanged from the current regulations, including the definitions for “wetlands”, “ordinary high water mark”, and “high tide line”. Some of these have been redefined, including definitions for “tributary” and “ditch”. The rule also defines several key terms, that while used colloquially, are added to the regulation for the first time, including definitions for “ephemeral”, “intermittent”, “perennial”, “prior converted cropland”, “snowpack”, “typical year”, “upland”, and “waste treatment system”.