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January 30, 2023

EPA Finalizes Waters of the United States Rule

On January 18, 2023, the US Environmental Protection Agency (EPA) and the US Army Corps of Engineers (USACE) announced a final rule (Final Rule) defining “waters of the United States” (WOTUS) that are protected under the Clean Water Act. The Final Rule repeals the 2020 Navigable Waters Protection Rule (2020 Rule), reverts to a definition that is consistent with the pre-2015 definition of WOTUS, and accounts for recent Supreme Court interpretations. 

WOTUS refers to several types of surface waters regulated by the EPA and USACE:

1.    Traditional navigable waters, the territorial seas, and interstate waters 
2.    Impoundments of other jurisdictional WOTUS 
3.    Tributaries to either of the above waters, or when the tributaries meet the “relatively permanent” standard or the “significant nexus” standard, (collectively, “jurisdictional tributaries”)
4.    Wetlands adjacent to traditional waters, wetlands adjacent and with a continuous surface connection to relatively permanent tributaries and impoundments, and wetlands adjacent to other jurisdictional tributaries when those wetlands meet the “significant nexus” standard
5.    Intrastate lakes and ponds, streams, or wetlands as defined in 1–4 above that meet either the “relatively permanent” standard or the “significant nexus” standard

The Final Rule focuses on the “relatively permanent” and “significant nexus” standards, which are key terms for determining whether a water body is jurisdictional. “Relatively permanent” refers to standing or continuously flowing waters and waters connected to traditional navigable waters as well as waters with a continuous surface connection to traditionally navigable waters or other waters that meet the relatively permanent standard. A “significant nexus” refers to waters that “significantly affect the chemical, physical, or biological integrity of traditional navigable waters.” 

The Final Rule expands upon the “significant nexus” standard by listing factors to evaluate whether hydrologic features meet the standard: 

(i)    The distance from traditional navigable waters 
(ii)    Hydrologic aspects (such as the frequency, duration, magnitude, timing, and rate of hydrologic connections, including shallow subsurface flow) 
(iii)    The size, density, or number of waters that have been determined to be similarly situated 
(iv)    Landscape position and geomorphology 
(v)    Climate variables (such as temperature, precipitation and snowpack) 

A wetland or tributary that is not adjacent to a traditional navigable water must meet one of the standards to fall under the definition of WOTUS. The 2020 Rule eliminated the significant nexus test as a ground for asserting jurisdiction. The Final Rule reinstates it.

As a result of the changes from the 2020 Rule, the Final Rule may impact Approved Jurisdictional Determinations (AJDs) issued by USACE depending on when the AJD was issued and its status.  An AJD is a determination by USACE of whether WOTUS are present. A positive AJD may trigger permitting requirements or a need to change the design of a project to avoid WOTUS. USACE states in the Final Rule that it will not rely on AJDs issued under the 2020 Rule for any pending or future permit actions. A “standalone” AJD, which refers to an AJD not associated with a permit action, remains valid, but USACE cautions that a “recipient of a standalone [2020 Rule] AJD should nonetheless be aware of the reliability considerations….”  

The Final Rule is expected to become effective in March 2023. However, in fall 2022, the US Supreme Court held oral arguments in Sackett v. EPA, a case challenging the EPA and USACE’s regulatory jurisdiction over remote wetlands, based on the “significant nexus” test. A future ruling in Sackett v. EPA may once again affect the EPA and USACE’s WOTUS interpretation. 

If you have any questions regarding the content of this alert, please contact Emma Marshall, associate, at; Dan Krzykowski, associate, at; Tom Paul, counsel, at; or another member of the firm’s Regulatory or Environmental Practice Areas or Energy Team.

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