Missoula County can’t simply ban large data centers, and it probably shouldn’t try. That is the core conclusion of a draft zoning study the county released on Oct. 21, three and a half months into a one-year pause on new and expanded data centers outside Missoula’s city limits.
The study, prepared by the county’s Planning, Development and Sustainability Department, is the homework commissioners assigned themselves when they adopted the emergency moratorium. That pause took effect July 9 and runs through July 8, 2027. It followed months of public worry over a proposed 7-megawatt AI data center in Bonner, east of Missoula.
“First and foremost, the study finds that data centers can have very real impacts on health, safety, and the environment, and that as a county, we need to take that seriously,” Svein Newman, the county’s Climate Action Program manager, told Montana Public Radio.
A long list of impacts
County staff catalogued the ways a large computing facility can affect its neighbors. The list runs from the obvious to the less discussed: heavy electricity demand and the risk that grid costs get shifted onto other ratepayers, water use for cooling, air emissions from diesel backup generators, constant fan and equipment noise, waste heat, hazardous materials stored on site, night lighting and disruption to wildlife.
“We have determined that there are potential threats to public health and safety in the natural environment associated with these types of developments,” county planner Patrick Swart said, according to reporting from Missoula television stations.
Commissioner Josh Slotnick has pointed out that the county’s existing rules were written for a different industry. “Back then, data center meant something very different then what it means right now,” he told NBC Montana. A server room in an office park and a multi-megawatt AI campus can fall under the same land-use label.
Why not a ban
Many residents who spoke during the moratorium debate wanted the county to keep data centers out entirely. The study says that route is likely closed. Montana’s Right to Compute Act, passed by the Legislature in 2025, limits how far state and local governments can restrict the use of computing resources, and county staff concluded an outright prohibition probably would not survive.
“I think it’s sort of the elephant in the room,” Newman told MTPR. “A lot of people will say ‘why not just ban them,’ but one of our findings is that it’s likely not permissible under Montana’s Right to Compute Act.”
Instead, the study recommends what Swart described as “comprehensive zoning that’s tailored to address the specific data center impacts that we’ve identified.” In practice that means rules on where such facilities can be sited, setbacks from homes, noise and lighting limits, how waste heat is handled, and controls on backup generation.
The county’s other recommendations reach beyond its own code. Staff suggest Missoula County intervene in NorthWestern Energy’s large new load tariff case before the Montana Public Service Commission, the proceeding that will help decide who pays when a single customer adds enormous demand to the grid. The study also suggests working with the 2027 Legislature on state-level protections, and it anticipates that commissioners may extend the moratorium into a second year to give zoning work time to finish. An extension would require another public hearing.
Bonner and beyond
The Bonner proposal is what pulled the issue into public view, but the study is written for the whole unincorporated county. Residents organized as Montanans Against Data Centers have followed the process closely since the moratorium debate.
Newman has said some issues, noise in particular, may be worth addressing sooner than a full zoning overhaul, according to the Missoula Current.
Montana’s debate over energy demand is not limited to Missoula. The PSC’s decision on the NorthWestern and Black Hills merger and the coming tariff case both bear on how large new customers are served and billed.
The draft is open for public review. County staff were scheduled to present it at a public meeting on the evening of Oct. 27 at the Home Arts Building at the Missoula County Fairgrounds. The Consolidated Land Use Board will get an overview on Nov. 4 at 6 p.m., and the Board of County Commissioners has set a hearing for Nov. 12 at 2 p.m., where the next steps, including any extension of the moratorium, are expected to come up.