Upper Missouri Waterkeeper Files Constitutional Challenge to Montana’s New Septic Pollution Exemptions & Approval of Big Sky’s Quarry Subdivision
BOZEMAN, MT – On Friday, Upper Missouri Waterkeeper filed a lawsuit against the Montana Department of Environmental Quality (DEQ) challenging the constitutionality of new state law that exempts subdivisions using septic systems from pollution control review. The lawsuit challenges DEQ’s use of those new septic exemptions to approve Phase 2 of the Quarry Subdivision, a 45-unit residential and commercial subdivision in Big Sky, located just a quarter mile from the Gallatin River, despite hundreds of public comments in opposition. The lawsuit was served to DEQ yesterday.
“There’s no reasonable dispute that each additional contribution of nutrient pollution into Montana’s rivers, including the Gallatin, exacerbates harm to the environment. The State has a duty to make science-based decisions that address and adequately control the impacts of development on waterway health, and not to undermine waterway protections by the passage of industry-friendly exemptions that create death-by-a-thousand-cuts for Montana’s waterways,” said Guy Alsentzer, Director of Upper Missouri Waterkeeper. “Best-available science is clear that new state laws reflect the insatiable demand to develop and don’t protect local waterways from harm. We have no choice but to act and vindicate our members and the public’s right to a clean and healthful environment, including rivers free from subdivision pollution. The future of the Gallatin and countless other Montana rivers, along with the businesses, communities, and downstream users they support, depends upon it.”
Upper Missouri Waterkeeper submitted technical comments opposing approval of the Quarry Subdivision Phase 2, including three expert scientific reports pinpointing how the addition of more septic wastes to the Gallatin River will harm local water quality and contribute to the continued contamination of that river. On April 29, 2025 DEQ issued an approval of Phase 2 of the Quarry Subdivision, but failed to meaningfully respond to expert evidence pinpointing how the subdivision’s new pollution discharges will, in combination with other nutrient pollution sources, cause more harm in the Gallatin River.
Two river-based businesses joined the organization as member-supporters willing to share how nutrient pollution negatively affects their businesses and values, and to speak up for Montanans’ constitutional right to a clean and healthful environment.
Founder and owner of Montana Whitewater, Bill Zell, a longtime member of Upper Missouri Waterkeeper with 33 years of guiding experience throughout Montana, is concerned about the impact on his river business and on other businesses. Montana’s outdoors generate an estimated $7 billion per year and support over 71,000 jobs.
“The health of the Gallatin River is integral to our business, livelihoods, and well being. If the river continues to be damaged by adding more pollution to an already sensitive river, it will deter visitors from coming to our area, costing jobs and revenue for our community. Development at the expense of our outdoor economy, businesses, jobs, and way of life violates our state constitutional rights. Algal blooms and increased water temperatures already threaten the river’s ecosystem,” says Bill Zell of Montana Whitewater. “I’ve guided on the Gallatin for 33 years, and I’ll never forget having to explain to guests why the water was suddenly an unnatural color, why the rocks were slimy, and why one of Montana’s most iconic and pristine rivers is now sick with pollution. That was in 2018, and what should have been a clear warning has been ignored as development has continued to boom. I’ve seen the changes over the years. This isn’t just about what I love, it’s about what my family, our employees, and our guests love. This is harming everyone, and for no good reason.”
Fellow Upper Missouri Waterkeeper supporter and owner of Montana Troutchasers, Jason Fleury, who’s guided on Southwestern Montana rivers for over a dozen years, also spoke up for the importance of science-based river protections. Fleury’s family business, employees, and livelihood depend on healthy waterways and fisheries. According to Montana Fish, Wildlife, and Parks, fishing in Montana generates over $900 million in economic impact annually.
“As a fly fishing guide, small business owner, and Montanan who’s spent my life on these rivers, I’ve seen firsthand how pollution is changing our waterways—from worsening algal blooms on the Gallatin to creeping impacts on the Madison, Big Hole, and beyond. Using outdated septic systems for new development along already stressed rivers is reckless and short-sighted. It’s not just a problem here in the Canyon; it’s a statewide failure to protect our fisheries and the communities that depend on them. One-size-fits-all septic exemptions ignore science and the reality on the ground. They’re a surefire way to turn some of the best trout rivers in the world into cautionary tales. We need pollution controls that protect clean water, not exemptions that greenlight more harm in violation of everyone’s constitutional rights to a clean and healthful environment,” said Jason Fleury, guide and owner of Montana TroutChasers.
Waterkeeper’s key concerns with Quarry Phase 2, many of which are currently being litigated for Phase 1 of the development, include:
- No analysis of wastewater impacts: The Environmental Assessment (EA) fails to show how wastewater from new septic system pollution will affect groundwater and the mainstem Gallatin River, despite clear hydrologic connections, which were recently reiterated in a groundwater study by the Montana Bureau of Mines and Geology.
- The Gallatin River is already impaired: The river already has a federal Clean Water Act impairment designation due to recurrent algal blooms linked to nutrient pollution. The approval of any additional pollution inputs that cause and contribute to those algal blooms is wrong, harmful, and unlawful.
- Unlawful and inadequate review: DEQ ignored its legal duty to consider the cumulative impacts of wastewater on nearby water resources, despite a court order requiring the agency to do so on another Big Sky subdivision in 2022. The recent rules instituted by DEQ create exceptions for pollution by ignoring the cumulative, total impact of pollution from the entirety of the project by splitting it into phases.
A timeline of the Quarry development with additional background is available here. Upper Missouri Waterkeeper brings this legal action on behalf of every Montanan who values clean water, healthy rivers, our outdoor economy, and a future where public trust resources are protected, not sacrificed. The Montana Constitution is clear: the right to a clean and healthful environment belongs to all of us and must be safeguarded for present and future generations.
Additional Information:
Upper Missouri Waterkeeper’s lawsuit challenges the constitutionality of Montana’s Senate Bill 285, passed in 2023, the subsequent administrative rules adopted in 2024, and now DEQ’s first application of these rules in approving the Quarry Subdivision Phase II. The Lawsuit Notes that:
Quarry Subdivision, Phase 2, an agency decision that explicitly relies on Montana’s new statutory and regulatory nonsignificance exemptions for a class of subdivision nutrient pollution discharges, Mont. Code Ann. § 75-5-301(5)(e), ARM 17.30.715(4), 17.30.1022(1)(d), and to challenge the constitutionality of those exemptions from Nondegradation Policy under the Water Quality Act, Mont. Code Ann. § 75-5-303. A live controversy lies in the Department’s ongoing implementation of these new exemptions to Nondegradation Policy review and pollution permitting under the Water Quality Act (WQA), and in DEQ’s application of those laws to exempt new subdivision nutrient pollution discharges of the Quarry Phase 2 from Nondegradation Policy, both of which are harming Plaintiff and infringing on its constitutional rights.
The sweeping exemption used to approve the subdivision allows up to 15,900 gallons of wastewater and 1 pound of nitrogen pollution per day—more than a tanker truck’s worth of wastewater—without review nor scientific basis. The exemptions grant flawed, generic engineering assumptions that ignore a river’s unique hydrology, pollution load, and ecological limits. It does not account for existing impairment or additional development phases, setting a precedent for more water pollution across Montana.
DEQ’s authorization of four new community septic systems in Phase 2 of the Quarry Subdivision sanctions the discharge of 11,500 gallons-per-day of nutrient laden pollution into groundwater that is hydrologically connected to, and conveys nutrient pollutants discharging into the Gallatin River, which is already impaired for nuisance algal blooms. The Quarry Phase 2 is one of the first times DEQ has applied new nonsignificance rules to exempt subsurface wastewater disposal for new a class of subdivision development from otherwise mandatory Nondegradation Policy review under the WQA.
The state is skirting its constitutional duty to safeguard Montanans’ right to a clean and healthful environment by presuming these systems are universally protective. In the case of the Gallatin River—already officially impaired by nutrient pollution—DEQ’s piecemeal approval strategy represents a race to the bottom, undermining both the Clean Water Act and the Montana Water Quality Act by failing to evaluate cumulative harm or require proof that pollution won’t reach the river.
The addition of wastewater-based nutrient pollutants into the middle segment Gallatin River causes and contributes to nuisance algal blooms, including the growth of the macroalga type cladophora, which thrives in nutrient-contaminated waters under conducive conditions, has been documented repeatedly in the middle segment Gallatin River, and was a basis for that river’s impairment determination by DEQ and the Environmental Protection Agency (EPA). The cumulative impacts and synergistic effects of nutrient pollutants in freshwater river systems mean the Quarry Phase 2’s wastewater discharges, in conjunction with other sources of nutrient pollution, cause or contribute to nuisance algal growth, lowered water quality, and diminishment of constitutionally protected and societally important uses of the Gallatin River such as aquatic life and recreational uses.
This lawsuit is fundamentally about accountability: it seeks to restore the constitutional guardrails around pollution control, prevent further degradation of iconic rivers like the Gallatin, and uphold the principle that development must prove it won’t harm Montana’s waters. It challenges an illegal and dangerous policy shift prioritizing unchecked development over science, water quality, and the public interest. At stake is more than one subdivision or one stretch of river, but whether Montana will honor its constitutional promise to protect our shared waters and landscapes, or allow pollution-by-exemption to become the new normal.