On January 18, 2023, the Biden administration published its Final Rule revising the definition of “Waters of the United States” (WOTUS) under the Clean Water Act (CWA). Wetlands and waterways that meet the definition of WOTUS are protected by the CWA and subject to the U.S. Environmental Protection Agency’s and Army Corps of Engineers’ jurisdiction. However, the term is not defined in the statute. As such, the federal agencies’ interpretation of WOTUS determines which waters are subject to the CWA permitting requirements.
The extent of the federal government’s authority under the CWA has been controversial since the passage of the CWA in 1972. The Final Rule marks the federal agencies’ third attempt to redefine WOTUS since 2015. The latest definition under the Final Rule replaces the Trump-era rule that narrowly interpreted WOTUS.
The new definition extends CWA jurisdiction to “interstate waters” and their adjacent wetlands. Under the Final Rule, wetlands are considered “adjacent” if they have a “relatively permanent,” continuous surface connection to interstate waters or if they significantly affect the chemical, physical, or biological integrity of those protected waters (i.e., there is a “significant nexus” between the wetlands and federally protected waters). Unlike previous definitions established under both the Obama and Trump administrations, the definition in the Final Rule does not impose a distance-based limitation on which wetlands may be considered “adjacent” and thus federally protected.
The Final Rule will become effective on March 20, 2023. However, a pending case before the Supreme Court could affect the viability of the Final Rule. In Sackett v. Environmental Protection Agency, the Supreme Court is considering a challenge to the “significant nexus” standard. The Court’s decision, which is expected in the coming months, could require the Biden administration to further revise and refine definition of WOTUS. Furthermore, lawsuits challenging the Final Rule have already been filed, with two suits filed the day the Final Rule was published.
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