The Environmental Protection Agency (EPA) has put forward a proposal to significantly alter a crucial section of the Clean Water Act, a move that legal experts and tribal advocates warn could severely diminish the ability of Indigenous nations to safeguard their water resources and uphold ancestral treaty rights. The proposed revisions to Section 401 of the Clean Water Act aim to streamline the permitting process for federal projects but, in doing so, would curtail the oversight powers that states and tribes currently possess. This regulatory shift strikes at the heart of tribal sovereignty, limiting their capacity to enforce environmental standards and protect the health of their citizens and ancestral lands.

At issue is the authority granted under Section 401, which requires developers seeking federal permits for projects impacting waterways—such as dams, mines, data centers, or pipelines—to obtain certification from the relevant state or tribe. This certification confirms that the project will comply with federal water quality standards. Historically, and particularly following a 2023 regulatory update under the Biden administration, this review process has allowed tribes and states to conduct comprehensive assessments, often referred to as evaluating the "activity as a whole." This holistic approach considers a wide spectrum of potential environmental harms, including the risk of spills, impacts on culturally significant sites, and threats to aquatic ecosystems and wildlife.

The EPA’s new proposal, however, seeks to narrow the scope of these reviews to focus solely on "discharge only." This means that both states and tribes would be restricted to evaluating projects based primarily on the quantity of pollutants they are projected to release, effectively sidelining broader concerns about water contamination, habitat destruction, and the cumulative effects of development on vital water bodies. This narrower focus represents a significant departure from the more expansive, ecosystem-based review that tribal nations have relied upon to protect their environments.

Furthermore, the proposed rule introduces substantial changes to how tribes can acquire the authority to regulate water quality under the "Treatment in a Similar Manner as a State" (TAS) program. The TAS program is one of the few avenues through which tribes can exercise regulatory power comparable to states, enabling them to set conditions and enforce standards to prevent pollution of waters within or near their territories. To date, only 84 tribal nations have achieved TAS status, a testament to the rigorous requirements and resource commitments necessary to gain this authority. The current framework under Section 401 allows tribes that can demonstrate sufficient capacity and resources to conduct water quality reviews, thereby extending regulatory powers beyond those with the largest governmental structures. The proposed change, however, would restrict this authority, reserving evaluation powers for TAS tribes through a separate and more demanding authorization process, potentially excluding many tribes from meaningful participation in federal project reviews.

Legal experts emphasize the critical role of these regulatory tools in protecting tribal interests. "Treaty rights are one of the strongest mechanisms to enforce against the federal government, against the state, against third-party actors, and in litigation," explained Heather Tanana, a law professor at the University of Denver. "It takes years, it takes money, it’s complicated to do, and so you want these other mechanisms." The proposed rule, by undermining these established mechanisms, could force tribes to rely more heavily on costly and time-consuming legal battles to defend their water rights and environmental integrity.

The challenges in securing TAS status highlight the disparities in resources among tribal nations. As Tanana pointed out, "There’s such a wide variance in tribes of what resources are available to them. Do they have other sources of revenue, right? How many staff do they have? Do they have their own environmental departments? Is it one person, or is it 10?" The proposed rule risks exacerbating these inequalities, creating a tiered system of regulatory authority that favors tribes with greater financial and human capital, while diminishing the voice and influence of those with fewer resources.

During the Biden administration, tribal governments actively advocated for a baseline rule that would grant all tribes some level of input on federal projects, even if they had not yet achieved TAS status. This effort aimed to ensure that every tribe had a voice in decisions affecting their waters. However, industry opposition during the public comment period and the subsequent political shift in 2024 led to the withdrawal of that proposed rule by the EPA in December. The current proposal appears to be a response to those pressures, prioritizing industry concerns over tribal environmental sovereignty.

The impact of tribal review on project approvals has been demonstrably limited, according to data. Patrick Hunter, a senior attorney at the Southern Environmental Law Center, noted that out of approximately 7,500 projects submitted during the Biden administration, fewer than 1% were denied. The vast majority were approved with conditions, such as the implementation of mitigation measures or the installation of sediment traps to prevent water pollution during construction. Tribal reviews have yielded similar outcomes, with a strong emphasis on ensuring projects proceed with minimal environmental damage.

The EPA’s own 2025 report on tribal consultations underscored widespread opposition to the proposed changes. "The clear feedback from the tribes was, ‘Don’t change it,’" Tanana stated, relaying the consistent message from tribal leaders. "You’re going to make it harder for us to exercise our sovereignty to protect our waters and protect our community." This strong consensus among tribal nations indicates a deep concern about the potential consequences of the proposed rule.

A 30-day public comment period on the proposed rule is currently underway, allowing stakeholders to voice their opinions. However, given the strong opposition from tribal governments and environmental advocates, the rule is widely expected to face significant legal challenges once it is finalized.

"Tribes have an obligation to care for the rivers and waterways that have sustained their communities since before the existence of the United States and are weighing every option to protect their way of life," said Gussie Lord, head of tribal partnerships at Earthjustice. This sentiment reflects the profound historical and spiritual connection Indigenous peoples have with their lands and waters, and their determination to defend these vital resources against perceived threats. The proposed EPA rule represents a critical juncture in the ongoing struggle for environmental justice and tribal sovereignty, with far-reaching implications for the health of the nation’s waterways and the well-being of its Indigenous communities.