On May 27, 2015, the U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers issued a final rule regarding the definition of “waters of the United States” protected under the Clean Water Act (CWA). By clarifying the definitions of jurisdictional waters, the rule has implications for entities applying for permits under the CWA that hinge on the meaning of “waters of the United States,” particularly section 404 permits for discharge of dredged or fill material and wetlands impacts.

The rule is intended to clarify CWA jurisdiction under the significant nexus standard developed by the Supreme Court, under which only water bodies with a “significant nexus” to navigable waterways fall under the CWA’s regulatory authority. See United States v. Riverside Bayview Homes, 474 U.S. 121 (1985); Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers, 531 U.S. 159 (2001); Rapanos v. United States, 547 U.S. 715 (2006). But what “significant nexus” means has been debated and litigated for years, and EPA officials conceded that regulatory revisions were needed to provide greater clarity.

While some view the new rule as broadening the scope of CWA jurisdiction, EPA claims that the rule does not protect any types of waters that are not already covered by the CWA or add any new permitting requirements. Instead, EPA maintains that the rule attempts to ameliorate “confusion and uncertainty” that has resulted from the existing case-specific approach to identifying jurisdictional waters by adding specific definitions and bright-line limits to aid in identifying waters subject to CWA permitting requirements. EPA Notice of Proposed Rule, 79 Fed. Reg. 22188 (April 21, 2014). In fact, the preamble to the rule states that “[f]ewer waters will be defined as ‘waters of the United States’ under the rule than under the existing regulations.” The preamble states that the rule narrows the scope of jurisdictional waters, in part by adding exclusions for waters that reflect the current regulatory practice and by adding a specific definition for jurisdictional tributaries. The rule designates certain categories of waters as jurisdictional or non-jurisdictional in all instances, while others are subject to the case-specific significant nexus test.

The new rule has been controversial since it was proposed last year, with opposition voiced by farmers, industry groups and some local governments. Several bills aimed at stopping the rule from taking effect were introduced in Congress, including one sponsored by Sens. Jeff Flake and John McCain from Arizona. In a letter to EPA Administrator Gina McCarthy in May of 2014, the senators wrote that EPA’s then-proposed rule “dramatically expands federal jurisdiction and will likely yield only the next step in an unnecessarily iterative process and create significant regulatory uncertainty.”

EPA engaged in a significant media campaign regarding the rulemaking, emphasizing the importance of protecting the nation’s waters while also countering attacks that the new rule was an expansion of CWA jurisdiction. It is clear that there will continue to be significant litigation regarding this issue, including likely legal challenges to the final rule itself.