The Environmental Protection Agency has proposed revisions to the Clean Water Act that would restrict tribes' and states' ability to review federal projects for water quality impacts. Experts warn this could undermine treaty rights and sovereignty for Native American nations. The changes revert to narrower oversight established before 2023.
Earlier this month, the Environmental Protection Agency announced a proposal to modify Section 401 of the Clean Water Act, which governs water quality certifications for federal projects like dams, mines, and pipelines. Under current rules, set in 2023 during the Biden administration, tribes and states perform comprehensive "activity as a whole" reviews, assessing pollution discharges alongside risks to cultural resources, wildlife, and spill prevention.
The proposed rule shifts to "discharge only" evaluations, focusing solely on pollution releases and limiting broader oversight. This affects the Treatment in a Similar Manner as a State (TAS) program, through which only 84 tribal nations currently hold authority to regulate water quality near their lands. The change would confine such powers to TAS tribes via a stricter authorization process, excluding others despite demonstrated capacity.
"What the Trump administration is proposing to modify here is a really important tool for states and tribes, because it gets at their ability to put conditions on or, in extreme cases, block projects," said Miles Johnson, legal director at Columbia Riverkeeper.
Legal experts like Heather Tanana, a law professor at the University of Colorado, highlight the reliance on treaty rights for enforcement, noting the challenges of litigation. "Treaty rights are one of the strongest mechanisms to enforce against the federal government," she said. Tanana pointed to resource disparities among tribes, with some lacking dedicated environmental staff.
The Biden-era rule, which allowed baseline input for all tribes, was withdrawn in December 2024 amid industry opposition and the presidential election outcome. During that period, fewer than 1 percent of 7,500 projects were denied certification, with most approved under conditions like mitigation measures, according to Patrick Hunter of the Southern Environmental Law Center.
Tribes voiced strong opposition in the EPA's 2025 consultation report. "The clear feedback from the tribes was, 'Don’t change it.' You’re going to make it harder for us to exercise our sovereignty," Tanana relayed. A 30-day public comment period is ongoing, with litigation anticipated post-finalization.
"Tribes have an obligation to care for the rivers and waterways that have sustained their communities," said Gussie Lord of Earthjustice.
