Water watchdogs warn about state septic system program
Laura Lundquist
(Missoula Current) The state is proposing a program to give blanket approval to subdivision septic systems, but like many things in Montana, one size doesn’t fit all, according to some environmental watchdogs.
On Monday, three Montana environmental groups sponsored a webinar presenting their concerns about a draft programmatic environmental assessment that would allow the Department of Environmental Quality to approve septic systems statewide with a minimum of oversight. The DEQ is accepting public comment on the assessment until Friday, and the three organizations are asking Montanans to weigh in if they value clean lakes and streams.
The organizations are Upper Missouri Waterkeeper, Clark Fork Coalition and Montana Environmental Information Center.
“This is a mechanism for streamlining development, and it prioritizes a streamlined approach of subdivision review by DEQ as opposed to that necessary site-specific environmental scrutiny,” said Guy Alsentzer of Upper Missouri Waterkeeper. “That is, of course, a political choice that’s being made. DEQ is seeking to implement that political choice, but there are consequences of that choice. We’re not going to have a defensible level of rigor at a site-specific level that can prevent harm in the first place.”
DEQ released the draft programmatic assessment in early April. In its release, DEQ said the programmatic EA would take the place of preparing separate, project-specific environmental assessments for each septic system proposal because “potential impacts resulting from qualifying subsurface wastewater treatment systems are similar across Montana.” To qualify, subdivisions would have fewer than 300 drainfields and disturb less than 10 acres.
William Kleindl, Montana State University aquatic system ecology professor, said that didn’t take into account that different materials - clay, cobble, sand - make up the drain fields in various parts of the state and the type of material affects how quickly the groundwater flows and mixes with the wastewater.
One septic system might not add much pollution, but the combined effect of up to 300 drain fields can lead to excess nutrients - nitrogen and phosphorus - remaining in the groundwater that enters lakes and streams. Excess nutrients can impair streams, leading to algae blooms that rob the water of oxygen and threaten fish and other organisms.
Kleindl showed a map of the Gallatin River watershed where yellow dots representing septic systems blot out large areas of the map. Unsurprisingly, DEQ has found, adjacent to all those dots, many of the streams are impaired for nutrients. DEQ assumes that rivers can dilute a limited amount of nutrients, but many Montana rivers - about one-third of river miles assessed, according to DEQ - are past the point where they can dilute all the nutrients that development and industries, such as agriculture and mining, are releasing. And drought is only worsening the situation.
“As our rivers are drying, over time, our pollutants could remain the same, but our (diluting ability) goes down, which means our pollutant load goes up. That will lead to eutrophication. That’s what’s going on in the Gallatin River and other rivers in the state,” Kleindl said.
Missoula attorney Graham Coppes said DEQ’s programmatic plan was prompted by Senate Bill 285, passed by the Republican majority in the 2025 Legislature to say that the Montana Environmental Policy Act can be used to assess but not regulate environmental impacts. So if this programmatic plan is passed, DEQ couldn’t limit future 300-unit subdivisions.
However, Coppes said, the Montana Constitution’s right to a clean and healthful environment requires DEQ to investigate environmental impacts and enforce limits on projects that would foul the environment. The vast difference in Montana’s geology means some sites handle septic wastewater better than others, so each project should be looked at on a case-by-case basis, Coppes said. Instead of passing programmatic rules that could reduce water quality, DEQ should tell the Legislature it can’t legally adhere to SB 285.
A district judge recently ruled that’s what DEQ should have done instead of using a cookie-cutter environmental assessment to approve certain gravel pit permits. The 2021 Legislature had changed the law to reduce DEQ’s approval time and responsibilities, but the judge said that didn’t absolve the department of its diligence.
Wastewater treatment plants do the best job of protecting Montana’s water quality so the state should figure out how to incentivize their use instead of greenlighting septic systems, Coppes said. He pointed to Missoula County, which he said is doing a good job at extending the reach of municipal services to new developments, while in Bozeman, developers were allowed to build exempt subdivisions across the street from where municipal services were available.
“That’s the problem we’re seeking to address. One of the purposes of MEPA is to not only inform citizens of impacts but also to inform the government when the laws we have are insufficient to meet their obligations,” Coppes said.
Alsentzer rattled off several statistics illustrating Montana’s recent population surge and the fact that, since 2010, many homes have been built in rural areas where it can be “done on the cheap.” For example, in the Kalispell area, the population grew by 39% but only 8% of that occurred within the city limits. The development outside the city equates to a bigger burden of septic pollution in the groundwater and potentially the Flathead River.
“So when we have a programmatic approach that has potential flaws in terms of saying we’re not going to take a hard look at the receiving water; we’re not going to look at whether it’s impaired; whether it already has nasty biological effects - these are part and parcel of the concerns that our organizations are expressing,” Alsentzer said. “Our waterways are not healthy today. We’re already seeing the health of our waterways slip through our fingers, and a primary cause of that is related to widespread nutrient loading from a variety of sources.”
Send comments by May 1 to DEQ Engineering Bureau, P.O. Box 200901, Helena, MT 59620. Or email: DEQENGPubComment@mt.gov
Contact reporter Laura Lundquist at lundquist@missoulacurrent.com.