Final Revised WOTUS Definition Released

Revised WOTUS Definition Released

On January 23, 2020 the US EPA and the US Army Corps of Engineers (ACOE) signed off on the revised definition of Waters of the United States (WOTUS) under the Clean Water Act.  The revised definition is being referred to as the “Navigable Waters Protection Rule.”A pre-publication copy of the “Navigable Waters Protection Rule” has been released (navigable_waters_protection_rule_prepbulication).  Sixty days after publication in the Federal Register the revised WOTUS definition will go into effect.

The revised WOTUS definition describes the following four categories of waters to be regulated under the Clean Water Act.

  • The territorial seas and traditional navigable waters,
  • Perennial and intermittent tributaries to those waters,
  • Certain lakes, ponds, and impoundments, and
  • Wetlands adjacent to jurisdictional waters.

The revised WOTUS definition excludes the following categories from regulation under the Clean Water Act:

  • groundwater, including groundwater drained through subsurface drainage systems;
  • ephemeral features that flow only in direct response to precipitation, including ephemeral streams, swales, gullies, rills, and pools;
  • diffuse stormwater runoff and directional sheet flow over upland;
  • ditches that are not traditional navigable waters, tributaries, or that are not constructed in adjacent wetlands, subject to certain limitations;
  • prior converted cropland;
  • artificially irrigated areas that would revert to upland if artificial irrigation ceases;
  • artificial lakes and ponds that are not jurisdictional impoundments and that are constructed or excavated in upland or non-jurisdictional waters;
  • water-filled depressions constructed or excavated in upland or in non-jurisdictional waters incidental to mining or construction activity, and pits excavated in upland or in non-jurisdictional waters for the purpose of obtaining fill, sand, or gravel;
  • stormwater control features constructed or excavated in upland or in non-jurisdictional waters to convey, treat, infiltrate, or store stormwater run-off;
  • groundwater recharge, water reuse, and wastewater recycling structures constructed or excavated in upland or in non-jurisdictional waters; and
  • waste treatment systems.

EPA and the ACOE will hold a 1-hour webcast on February 13, 2020 to present the revised definition of WOTUS.  Link to register for the webinar:


In 2015 EPA and the Army adopted revisions to the definition of WOTUS under the Clean Water Act (the revisions were referred to as the Clean Water Rule).  Almost immediately, the Rule was challenged in court and implementation was halted in a number of States. In March 2017 EPA and the ACOE indicated their intent to rescind or revise the Clean Water Rule.  In October 2019  the EPA and the ACOE published “…a final rule to repeal the 2015 Clean Water Rule definition of Waters of the United States….and to restore the regulatory text that existed prior to the 2015 Rule.”  The repeal went into effect on December 23, 2019.  On February 14, 2019 EPA and the ACOE proposed for public comment a revised WOTUS definition.  The public comment period closed April 15, 2019; there were approximately 620,000 public comments submitted.

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About Dan Askenaizer

Dr. Askenaizer leads WQTS’ work on regulatory compliance support for many of our water agencies clients. Dr. Askenaizer tracks water quality and treatment regulations at the Federal and State levels and provides regulatory updates to our clients. Dr. Askenaizer has strong expertise in the development of Regulatory Monitoring and Compliance Plans (RMCPs), which he has completed for a number of water agencies. He has also been working on a number of projects dealing with the development of distribution system monitoring plans and review of nitrification control strategies. Prior to joining WQTS, Dr. Askenaizer was the Water Quality Manager for the Glendale Water and Power. Under his leadership, the Water Quality Group conducted a demonstration-scale study of chlorite for nitrification control and a pilot-scale study of biological treatment for removal of nitrate. Dan has 30 years of experience working on projects dealing with regulatory, water quality and public health issues. Dan has given numerous presentations at workshops and round-tables across the country for water utilities. Dan was instrumental in developing and implementing a Mentoring Program for water staff and was involved in a Sustainable Development team.