Legal Alert: U.S. EPA and U.S. Army Corps of Engineers Propose Rule Narrowing Definition of Waters of the United States and Federal Authority

Brian M. Babb

On December 11, 2018, the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Army (Army) jointly signed a 253 page proposed rule (Proposed Rule), to revise and narrow the definition of “Waters of the United States” (WOTUS) under the federal Clean Water Act (CWA). Both the Army and EPA are statutorily charged with administering critical water pollution control programs under the CWA, and the scope of all such programs is determined by the term WOTUS. Because the term WOTUS plays such a pivotal role in defining the scope and reach of critical federal water pollution control programs, that singular term has been the target of several prior EPA and Army rulemaking efforts and numerous lawsuits challenging prior rules. The Proposed Rule reduces the scope of the 2015 WOTUS rule, which is subject to significant ongoing litigation.

The Proposed Rule would narrow the definition of WOTUS, thereby eliminating both agencies’ authority to impose CWA permit and other water pollution control requirements on entities whose activities impact waterbodies or wetlands no longer considered to be WOTUS. Water features no longer considered to be WOTUS would not be subject to CWA restrictions. Such activities would include industrial wastewater discharges, the development or alteration of wetland properties, storm water runoff impacted by exposure to industrial activities, unprotected  outdoor materials handling, and construction activities. These and other CWA programs (e.g., oil spill prevention) impact a significant number of commercial activities, including manufacturing operations, commercial and residential real estate developments, construction activities, mining, and farming.

The Proposed Rule, if promulgated, would potentially put an end to years of uncertainty and controversy as to what constitutes WOTUS. It would supersede the definition of WOTUS adopted by the EPA and Army in 2015, which is subject to vociferous legal challenges and subsequent EPA and Army rulemakings. EPA and the Army will inevitably take months, if not a year or longer, to consider public comments and devise a final rule.  Upon publication, the final rule will most certainly become the target of numerous legal challenges. So at best, clarity as to what constitutes a CWA-regulated WOTUS likely will not be available until late this year if not later.  

In mid-2017, the EPA and the Army jointly issued a proposed rule to repeal the 2015 WOTUS rule, which repeal has not yet been finalized. In early 2018, the EPA and the Army then proposed to change the effective date of the 2015 WOTUS rule to 2020, which lead to numerous legal challenges. Due to various court decisions, the 2015 WOTUS rule is reportedly effective in 22 states and not effective in the other 28 states. States where the 2015 WOTUS rule are not effective rely on a 1986 rule and guidance.

Overview of Proposed Rule
Most importantly, the Proposed Rule would scale back the type of wetlands regulated under the CWA. The 2015 WOTUS rule regulates all wetlands with any “significant nexus” to traditionally navigable waters, while the Proposed Rule would limit federal jurisdiction to wetlands that “abut” or have a “direct hydrologic connection” with navigable waters.  

The 2015 WOTUS rule followed Justice Kennedy’s concurring opinion in the 2006 U.S. Supreme Court case of Rapanos v United States (Rapanos); he found that a navigable water regulated under the CWA as a water or wetland must possess a “significant nexus” to a navigable water, particularly if the wetland “significantly affects the chemical, physical, and biological integrity of other covered waters more readily understood as ‘navigable.’” In contrast, the Proposed Rule follows Justice Scalia’s narrower plurality opinion in Rapanos that (1) “only relatively permanent, standing or continuously flowing bodies of water forming geographic features” such as streams, oceans, rivers and lakes, and (2) “wetlands with a continuous surface connection” to a relatively permanent water qualify as WOTUS and are subject to regulation under the CWA.

Jurisdictional Waters
The Proposed Rule is intended to provide “clarity, predictability, and consistency” as to where the CWA applies.  The Proposed Rule creates six categories of waterways subject to CWA jurisdiction, which are:

  • traditional navigable waters;
  • tributaries to navigable waters, meaning perennial or intermittent rivers and streams that contribute flow to traditional navigable waters in a typical year;
  • certain ditches, such as those used for navigation, or those affected by the tide;
  • certain lakes and ponds that are similar to traditional navigable water or that provide perennial or intermittent flow in a typical year to a navigable water;
  • impoundments such as check dams and perennial rivers that form lakes or ponds behind them; and
  • wetlands that abut or have a direct hydrologic surface connection to another water of the U.S.

Under the Proposed Rule, traditional navigable waters, tributaries to those waters, certain ditches, lakes and ponds, impoundments of jurisdictional waters, and wetlands adjacent to jurisdictional waters would be federally regulated. Wetlands would only be subject to CWA jurisdiction if they abut navigable waters or have a direct, hydrological surface connection to jurisdictional waters in a typical year.

Non-jurisdictional Waters
Under the Proposed Rule, WOTUS would exclude: features that only contain water during or in response to rainfall such as dry washes or streams that only contain flow in response to a rain event; groundwater; agricultural ditches; prior converted farmland; artificially irrigated areas; storm water control features; and waste treatment systems.

Under the Proposed Rule, ‘interstate waters’ would no longer be considered an independent category of jurisdictional waters. No ephemeral streams and fewer ditches, lakes, ponds and isolated wetlands would be subject to the CWA jurisdiction, and wetlands would be considered adjacent to navigable waters in fewer situations. Some sources estimate that 60% of all waters in the U.S. and 80% of waters in the Southwest are ephemeral or flow seasonally, and would not be WOTUS.

The Proposed Rule redefines and narrows the scope of federal authority over WOTUS under the CWA. The Proposed Rule would continue to exert federal jurisdiction over traditional navigable waters, perennial and intermittent tributaries to such waters, lakes and ponds that are similar to traditional navigable waters, and wetlands the abut or have a direct hydrologic surface connection to traditional navigable waters. Waters outside the scope of the Proposed Rule would not be WOTUS, and would be subject to whatever protection or regulation is imposed by the states where they are located.

Comments on the Proposed Rule need to be made within 60 days of publication of the Proposed Rule, which has not yet been published in the Federal Register. A public hearing on the Proposed Rule has been postponed due to the partial federal government shutdown. Persons or companies potentially affected by the Proposed Rule should consider submitting comments within the comment period, which has not yet commenced.

A pre-publication version of the Federal Register notice is available at

On February 7, 2019, the U.S. Department of Defense and U.S. EPA issued a notice of public hearing in the Federal Register regarding the proposed rule revising the definition of “Waters of the United States” (WOTUS). The public hearing on the proposed rule has been scheduled for February 27 and 28, 2019, in Kansas City, Kansas. The proposed rule on WOTUS has not yet been published in the Federal Register. 

The Federal Register notice on the public hearing is available at:


On February 14, 2019, the U.S. Department of Defense and the U.S. Environmental Protection Agency issued a notice in the Federal Register regarding the proposed rule revising the definition of “Waters of the United States” (WOTUS). The public comment period on this proposed rule is 60 days, and closes on April 15, 2019.

The Federal Register notice on the proposed rule is available at:

Should you have any questions please contact Brian Babb at 513.579.6963.

KMK Law articles and blog posts are intended to bring attention to developments in the law and are not intended as legal advice for any particular client or any particular situation. The laws/regulations and interpretations thereof are evolving and subject to change. Although we will attempt to update articles/blog posts for material changes, the article/post may not reflect changes in laws/regulations or guidance issued after the date the article/post was published. Please consult with counsel of your choice regarding any specific questions you may have.


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