The Environmental Protection Agency (EPA) issued a clear warning to states and authorized tribes that their authority under Section 401 of the Clean Water Act (CWA) to deny or set conditions for projects requiring federal approvals is limited to protecting state water quality standards. On May 21, 2025, Acting EPA Assistant Administrator Peggy S. Browne issued a memorandum, “Clarification Regarding the Application of Clean Water Act Section 401 Certification,” to “reiterate the EPA’s longstanding position” that the CWA cannot be used as a “weapon to shut down projects for reasons with no basis in the statute or applicable regulations.” The memorandum further explains that the states’ or authorized tribes’ certifying authority is “limited to considering adverse impacts to water quality, and only such impacts insofar as they prevent compliance with applicable water quality requirements.”
Under the CWA, states and authorized tribes must decide within a “reasonable period of time,” not to exceed one year, whether to certify that a proposed project seeking a federal license or permit will comply with their water quality standards. In September 2023, the EPA promulgated revised regulations of CWA Section 401 (2023 Rule). As discussed in our previous legal alert, the 2023 Rule allowed states and authorized tribal authorities to review a project “as a whole,” seemingly broadening their authority over activities that may not typically be viewed as related to water quality issues. This memorandum was issued due to stakeholders’ concerns over the 2023 Rule and the use of it by states and authorized tribes to deny projects based on “potential impacts to air quality, traffic, noise, project preference, or economic impacts.” The memorandum reinforces that “CWA Section 401 is limited to addressing only water quality-related impacts” connected to a specific water quality requirement and that the 2023 Rule does not authorize states or tribes to deny or condition a 401 Water Quality Certificate based on generalized concerns about water quality or potential impacts not connected to water quality.
The memorandum goes on to say that the EPA will use “future Federal Register notice and recommendations docket to identify additional areas of implementation challenges and regulatory uncertainty” related to the 2023 Rule. The 2023 Rule is also currently being challenged by Republican-led states and energy industry groups in Louisiana et al. v. U.S. Environmental Protection Agency et al., Index No. 2:23-cv-01714, in the US District Court for the Western District of Louisiana, arguing it exceeds the EPA’s statutory authority.
Notably, this memorandum supports developers of critical energy and infrastructure projects and is key to the Trump administration’s “Powering the Great American Comeback” initiative. It is another clear signal that this administration intends to limit states’ ability to block energy projects.
If you have any questions regarding the content of this alert, please contact Emma Marshall, associate, at emarshall@barclaydamon.com, or another member of the firm’s Environmental, Regulatory, Energy, or Project Development Practice Areas.