UPDATE: Montana Court Dismisses Case to Protect Big Hole River
(Bozeman, Montana) – The show cause hearing for Upper Missouri Waterkeeper v. Montana Department of Environmental Quality is rescheduled for June 12, 2025, at 9 a.m., before Judge Menahan. DEQ will be required to explain why it is not following its clear legal duty to apply numeric nutrient water quality standards when considering the impairment petition submitted for the Big Hole River.
“We are disappointed by DEQ’s failure to apply best available science and chart a path forward for restoring the Big Hole River and protecting wild trout,” said Upper Missouri Waterkeeper Executive Director Guy Alsentzer. “Numeric nutrient pollution standards are still the law of the land, and the Big Hole River needs formal recognition of challenges on the ground so that meaningful restoration planning can get underway. This is particularly true as continued drought is predicted this season, exacerbating challenges already facing the world-class river and wild trout. Both our wildlife and jobs and local businesses are on the line if the Big Hole loses its health.”
An impairment designation on the Big Hole River would bring formal focus and resources to solve documented nutrient pollution problems. It would also open up pass-through funding and in-kind cost-sharing for communities, federal and state agencies, and landowners, enabling shovel-ready projects capable of restoring the river’s health and protecting wild trout and other sensitive aquatic life.
In the latest development in this case, on June 2, Upper Missouri Waterkeeper submitted a response opposing efforts by the Montana Department of Environmental Quality (DEQ) to dismiss the case.
In the motion, UMW Executive Guy Alsentzer notes, “The very essence of mandamus is the necessity of a speedy remedy if, in this case, water quality in the Big Hole is to be protected. This Court, much less Defendant the Montana Department of Environmental Quality, have constitutional obligations to “maintain and improve a clean and healthy environment for this and future generations,” yet “to the contrary, Defendant urges delay, delay, delay.”
Waterkeeper filed the lawsuit on May 9, 2025, after DEQ denied their February 13, 2025, petition. The necessity of this lawsuit was a problem of DEQ’s own making: DEQ’s denial letter did not find issues in data quality, or a lack of data, instead explicitly refusing to apply numeric nutrient criteria based on the passage of Senate Bill 358 from the 2021 Legislative Session. Numeric nutrient criteria represent best-available science reflecting an anticipatory and preventative approach to river pollution control. Senate Bill 358 sought to eliminate numeric nutrient standards, but was rejected and disapproved by the Environmental Protection Agency (EPA) in 2022 as contrary to federal law.
Therefore, when DEQ made a decision on the Big Hole Petition, it had a mandatory duty to apply numeric nutrient criteria as required by federal law under the Clean Water Act. Waterkeeper’s Response to DEQ’s motion to dismiss concludes that “The Court should deny DEQ’s Motion to Dismiss on all counts, issue a writ of mandate requiring DEQ to reconsider Waterkeeper’s Petition in light of and after application of numeric nutrient criteria ….and declare that DEQ must apply numeric nutrient criteria in all CWA decision-making unless and until EPA approves a revision of water quality standards.”