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On December 11, 2018, the U.S. Environmental Protection Agency (EPA) and the Department of the Army (Army) proposed a revised definition of “Waters of the United States” (WOTUS) that clarifies federal authority under the Clean Water Act (CWA). The term WOTUS can be traced back to the 1972 Federal Water Pollution Control Act Amendments, which defined “waters of the U.S.” as waters regulated under the CWA.

Water of US_3 pics

WOTUS Redefined

There have been numerous court cases and rulings affecting the definition of WOTUS. Highlights of the most significant cases and resulting actions are summarized below.

  • 2006: The Supreme Court case Rapanos v. United States introduced the concept that waters with a significant nexus to navigable waters are covered under the CWA. It also stated that waters of the U.S. include only those relatively permanent, standing, or continuously flowing bodies of water forming geographic features that are described in ordinary parlance such as streams, oceans, rivers, and lakes. This caused considerable confusion and uncertainty regarding the jurisdiction of the CWA.
  • 2015: EPA and Army finalized the Clean Water Rule, which broadened the definition of WOTUS by expanding the categories of regulated waters.
  • 2017: President Trump issued Executive Order 13778, instructing the agencies to review the 2015 Clean Water Rule and then rescind or revise it as appropriate.
  • 2018: EPA and Army published a new rule, referred to as the Suspension Rule, delaying the effective date of the 2015 rule until 2020.
  • 2018: The U.S. District Court for the District of South Carolina vacated the Suspension Rule on the basis that the agencies did not provide a "meaningful opportunity" for comment on the rule and therefore did not comply with the Administrative Procedure Act.

The District Court ruling effectively reinstates the 2015 Clean Water Rule in 22 states and the District of Columbia; in the other 28 states, the pre-2015 regulations and guidance are currently in effect due to other court cases and injunctions.

Current Rulemaking

The proposed definition announced on December 11, 2018, would replace the 2015 Rule and the pre-2015 regulations. The proposed rule rolls back the inclusion of certain waters that were added in the 2015 WOTUS definition, thereby limiting CWA authority. It also limits the definition of WOTUS to those waters that are physically and meaningfully connected to traditional navigable waters, which essentially eliminates the significant nexus determination established in 2006.

The major changes in the proposed definition compared to that in the 2015 rule and pre-2015 regulation are summarized in Table 1.

Waters of US chart

Listed below are highlights of the proposed exclusions under the WOTUS definition.

  • Ephemeral streams that flow only after heavy rains or during snow melt
  • Groundwater
  • Ditches that do not meet the proposed definitions to be regulated
  • Prior converted cropland
  • Storm water control features excavated or constructed upland to convey, treat, infiltrate, or store storm water run-off
  • Wastewater recycling structures
  • Waste treatment systems
  • Waters not included in the proposed categories in the table above

EPA and Army are requesting comments on the proposed rule, including those aspects listed below that pertain to the definition of WOTUS.

  • Whether existing guidance regarding the scope of traditional navigable waters should be updated to help improve the clarity of the proposed rule
  • The proposed removal of interstate waters as a separate regulated category in the rule
  • Whether certain categories of impoundments should not be jurisdictional, such as certain types of impoundments that release water downstream infrequently or impede flow downstream such that the flow is less than intermittent
  • Whether the definition of tributary should be limited to perennial waters only
  • How effluent-dependent streams should be treated under the proposed tributary definition
  • Whether streams that contribute less than intermittent flow to a traditional navigable water or territorial sea should be included in the tributary definition
  • The proposed definitions of ditch, perennial, intermittent, typical year, and ephemeral, among others
  • The proposed interpretations of adjacency in regard to the wetlands category
  • Tools that may be helpful in the implementation of the proposed wetlands category (NRCS, soil surveys, tidal gauge data, site-specific modeling, etc.)

On December 28, 2018, EPA and Army issued notice that a public hearing would be held on January 23, 2019, and comments on the proposed rule would be accepted for 60 days after publication of the rule in the Federal Register. As of this article going to print, the federal government shutdown has caused this meeting, and the start of the public comment period to be postponed; the updated hearing details will be posted on EPA's website at .

Comments can be emailed to , using the subject line "Docket ID No. EPA-HQ-OW-2018-0149."

For assistance on how this proposed rule may affect water permitting at your facility, please contact Trinity at (800) 229-6655.