Montana, a state renowned for its pristine natural beauty and abundant waterways, including the mighty Missouri River and the vast Flathead Lake, is now facing a significant rollback of environmental protections for its aquatic ecosystems. Following legislative action, and with recent backing from the Environmental Protection Agency (EPA) as of October, the state is moving away from its previously established numeric water-quality standards, a shift that environmental advocates and experts warn could jeopardize the health of its cherished rivers and lakes.

Historically, Montana was at the forefront of water pollution regulation in the United States. In 2014, it became the first state to implement numeric water-quality standards for dissolved nitrogen and phosphorus in wadable streams and certain river segments. These nutrients, commonly originating from sources such as mining operations, municipal wastewater treatment, and agricultural runoff, can have devastating effects when present in excess. Their proliferation triggers rapid algal growth, known as algal blooms, which not only mar the visual appeal of waterways but also critically deplete dissolved oxygen levels. This oxygen depletion can lead to widespread fish die-offs, block sunlight from reaching deeper aquatic life, and, in severe cases, release toxins harmful to human health if consumed through contaminated water.

Water-quality standards, approved by the EPA, serve as the benchmarks states and tribes set to ensure their waters remain safe for both human consumption and the survival of aquatic life. These standards inform a state’s environmental policy, guiding cleanup initiatives and the permitting process for "point-source polluters"—entities that discharge wastewater through pipes or ditches. Standards can be established numerically, setting specific maximum allowable levels for pollutants before detrimental effects like algal blooms occur, or narratively, by describing the ideal conditions of clean waterways based on various degradation parameters.

Earlier this year, Montana’s legislature passed a series of bills that effectively repealed the state’s numeric nutrient standards, reverting to the existing narrative standards. Environmental organizations and water-quality specialists widely regard narrative standards as less protective than their numeric counterparts. Numeric standards act as a proactive safeguard, compelling polluters to treat wastewater before significant environmental degradation becomes apparent. In contrast, narrative standards are typically invoked only after problems have already manifested, making them reactive rather than preventive. The quantifiable nature of numeric standards makes them a more robust and enforceable benchmark, whereas narrative standards allow for greater subjectivity and discretion for both regulated entities and environmental agencies.

The current transition to narrative standards has created considerable uncertainty, according to Scott Bosse, Northern Rockies regional director for the nonprofit American Rivers. The precise implementation strategy of Montana’s Department of Environmental Quality (DEQ) remains unclear. The DEQ, however, contends that narrative standards offer a more efficient approach to preventing excessive pollution. The department intends to assess each water body individually, tailoring anti-pollution strategies to the unique hydrological and ecological characteristics of each location. Andy Ulven, chief of the DEQ’s Water Quality Planning Bureau, stated that the department is focused on developing the most effective site-specific controls. Under the new framework, the DEQ will monitor factors such as the health of aquatic indicator species like mayflies, the prevalence of algal growth, and dissolved oxygen content to inform water policy. While dissolved nitrogen and phosphorus levels will still be considered, Ulven emphasized the need to examine the broader ecological context.

Despite these assurances, critics express skepticism, deeming the 2025 legislation vague and overly permissive. Nine watchdog groups have formally requested a moratorium on wastewater permits until a more concrete plan for implementing the narrative standards is established. This is not the first instance of Montana attempting to roll back its numerical nutrient standards. Previous attempts in 2020 and 2022 were rejected by the EPA, which cited potential violations of the Clean Water Act. This year’s reversal marks a significant departure, with the EPA approving the new rules on October 3, during a period of government shutdown.

Although Montana first introduced numerical criteria for nutrient pollution in 2014, the state’s enforcement of these standards has been notably lax. Instead of revising permits to meet the new requirements, the DEQ frequently extended existing ones. Now, over two dozen permit renewals are pending, affecting major urban centers like Billings and Missoula, as well as smaller towns such as Kalispell and Whitefish, whose waters flow into Flathead Lake. Adhering to the previous numeric standards would have necessitated substantial investments in upgrading the state’s generally outdated wastewater treatment infrastructure. Guy Alsentzer, executive director of Upper Missouri Waterkeepers, argued that modernizing wastewater treatment technology is a necessary long-term investment for the health of Montana’s waterways and its residents, acknowledging that funding such upgrades is a challenge.

More than 35% of Montana’s river miles and 22% of its lakes are currently classified as impaired due to pollution from sewage, industrial waste, and agricultural fertilizers. Environmental organizations are concerned that issuing a surge of new permits under the relaxed narrative standards could exacerbate existing pollution problems and open the door to further contamination.

The recent approval of Montana’s revised water-quality standards comes amid a broader trend of weakening environmental regulations nationwide. The implications of this shift extend beyond Montana, potentially signaling a more permissive stance from the EPA towards similar rollbacks in other states. Andrew Hawley, a staff attorney at the Western Environmental Law Center, noted that this development suggests states may perceive the EPA as receptive to weakening Clean Water Act protections.

In the interim, Montana’s vital water resources face increased vulnerability. The decision by both the state and the EPA to transition to narrative standards is viewed by environmental advocates as a significant risk to the state’s clean water, potentially undermining years of progress. The Sibanye-Stillwater platinum and palladium mine, situated along the East Boulder River, has been granted a new permit that allows for a more than fifty-fold increase in nitrogen discharge compared to its previous permit, which had established stricter numeric limits to be met over a decade. This permit renewal is being closely watched as an early indicator of how waterways will be managed under the new narrative standards regime.

This story was made possible with support from the Institute for Journalism & Natural Resources.