On January 18, 2023, the Environmental Protection Agency (EPA) and Army released the final rule on a revised definition of “Waters of the US (WOTUS). The final rule becomes effective on March 20, 2023. The rule re-establishes the pre-2015 WOTUS definition, with a few modifications. Under the new rule, there are five categories of jurisdictional waters, and eight exemptions. In addition, further clarity is provided on two key concepts in defining jurisdictional waters – the “relatively permanent standard” and the “significant nexus standard”.
The 5 categories of jurisdictional water considered to be WOTUS are:
- Traditionally navigable waters, which includes the territorial seas and interstate waters
- Impoundments of the traditionally navigable waters
- Tributaries of the traditionally navigable waters
- Adjacent wetlands to traditionally navigable waters, and
- Non-traditionally navigable waters such as intrastate lakes, ponds, streams, and wetlands that do not fall within the above categories.
A new definition was added in the final rule for “significantly affect”. To significantly affect a traditionally navigable water means having a material influence on the chemical, physical or biological integrity of that water.
The function and factors to be considered when making a WOTUS determination include:
- Contribution of flow
- Trapping, transformation, filtering and transport of nutrients and other pollutants
- Retention and attenuation of floodwaters and runoff
- Modulation of temperature, or provision of habitat and food resources for aquatic species
- The distance from the traditional navigable water
- Hydrological characteristics, such as frequency, duration, magnitude, timing, and rate of hydrologic connections, including shallow subsurface flow
- The size, density, or number of similarly situated waters
- Landscape position and geomorphology
- Climatological variables such as temperature, rainfall, and snowpack
When the U.S. Army Corps of Engineers is determining jurisdictional status and regulatory implications of the Federal Clean Water Act for intrastate lakes, ponds, streams, wetlands, and non-traditional navigable waters, the “relatively permanent” or “significant nexus” test is applied. The relatively permanent standard means the water body is relatively permanent, standing or continuously flowing, with a continuous surface connection to a traditionally navigable water, or to a relatively permanent tributary. The significant nexus standard means that the water body, either alone, or in combination with similarly situated waters in the region, significantly affect the chemical, physical or biological integrity of a traditionally navigable water, as defined above.
The final rule excludes the following waters from jurisdiction and definition of WOTUS:
- Groundwater (unless it emerges at the surface and reaches a jurisdictional surface water)
- Waste treatment systems
- Prior converted cropland
- Certain ditches
- Artificially irrigated areas, lakes, ponds, swimming pools or small ornamental water bodies
- Certain water-filled depressions
- Swales and erosional features
Why does this new definition matter? The new rule provides a federal definition that may reduce regulatory interpretation uncertainty. The new definition may impact several critical federal regulatory programs, such as Section 401/404 of the Clean Water Act, wastewater discharge permitting, development of water quality standards and management of dredged and/or fill material. Litigation is pending and injunctions and/or appeals have been the norm for implementation of new definitions of WOTUS in recent years.
Our natural resource and compliance and permitting experts continually monitor regulatory changes and litigation that affects the regulatory processes with the goal of providing our clients with up-to-date expertise for existing and future permitting needs. To find out more, please contact us using the form to the right and visit the EPA’s page on WOTUS.