The definition of “waters of the United States” is a critical component of the Clean Water Act (CWA) and one that has a long history of litigation and interpretation. On June 29, 2015, this history gained another chapter when the U.S. Environmental Protection Agency (EPA) and the Army Corps of Engineers published their latest interpretation of that definition in theFederal Register, the Clean Water Rule. The Clean Water Rule attempted to clarify what are jurisdictional “waters of the United States” under the CWA, drawing from a wealth of legal decisions, scientific studies, and public comments while trying to stay true to the legislative intentions of the act. Not surprisingly, shortly after the Clean Water Rule was published, a swell of lawsuits were filed challenging the new rule.
In response to the Clean Water Rule, numerous petitions were filed by interested parties in district and circuit courts around the country. In one of those cases, Ohio et al. v. EPA et al., No. 2:15-cv-2467 (S.D. Ohio filed June 29, 2015), Ohio and Michigan, later joined by Tennessee, alleged that, through the Clean Water Rule, the EPA and the Army Corps were attempting to expand their regulatory scope beyond what was allowed under federal law and claim authority over waters that were rightly within the jurisdiction of the states.