Bolthole Index county-legal census · checked 2026-08-08
Septic permitting in Montana is handled at the county level — county health departments approve systems in 49 of 56 counties.Every entry below names the approving authority for that county, cited to the authority’s own page.
Septic rules change and some cities run their own programs — treat this as a verified starting point, not legal advice. All states → Montana water rights & wells → Full Montana profile →
56 counties · county health departments · permit status scouted for 5
Beaverhead County (Wastewater regulations, under Montana DEQ)
Beaverhead County Wastewater System Regulations ↗Big Horn County Public Health Department (County Sanitarian), under MT DEQ rules
Big Horn County Public Health Department - Septic Permitting ↗Blaine County Environmental Health / Registered Sanitarian (Septic System Program)
Blaine County Environmental Health Sanitarian ↗Broadwater County Environmental Health
Broadwater County Environmental Health Septic Permit Application ↗Carbon County Environmental Health Department (with Montana DEQ review for subdivisions under 20 acres)
Carbon County Environmental Health ↗Carter County Sanitarian
Carter County, MT official website (Sanitarian) ↗Cascade City-County Health Department (CCHD)
Cascade County Septic Systems ↗Chouteau County Sanitarian / Chouteau County Public Health
Chouteau County Public Health ↗Custer County Environmental Health / Sanitarian (with Montana DEQ liaison)
Custer County Environmental Health ↗Montana DEQ (Sanitation in Subdivisions Act; local Septic Construction Authorization)
Montana DEQ - Engineering, Infrastructure & Subdivisions ↗Dawson County Sanitarian / Environmental Health
Dawson County Environmental Health (Sanitarian) ↗Anaconda-Deer Lodge County Environmental Health Department (Tri-County)
Anaconda-Deer Lodge County - Septic Systems / Wells (official site) ↗Fallon County Sanitation / Environmental Health
Fallon County MT - Sanitation/Environmental Health ↗Fergus County Health Department (Environmental Health)
Fergus County Regulations for Subsurface Wastewater Treatment Systems ↗Flathead City-County Health Department - Environmental Health (Sewage & Septic)
Flathead County - Sewage & Septic ↗Gallatin City-County Health Department (Environmental Health)
Gallatin City-County Health Department - Wastewater (Septic) Treatment ↗Glacier County Sanitarian / Health Department
Glacier County - Department Directory (Sanitarian) ↗Golden Valley County Sanitarian (Central Montana Health District)
Golden Valley County Sanitarian Services / Environmental Health ↗Tri-County Sanitarian (Tri-County Health Department serving Deer Lodge, Granite, and Powell counties)
Granite County Planning Department (Tri-County Sanitarian) ↗Hill County Health Department - Environmental Health
Hill County Health Department - Environmental Health ↗Jefferson County Environmental Health / Sanitarian
Jefferson County Montana Environmental Health | Sanitarian ↗Central Montana Health District (Central MT Environmental Health)
Judith Basin County - Central MT Environmental Health ↗Lake County Board of Health / Environmental Health
Lake County Wastewater Treatment ↗Lewis and Clark Public Health, Environmental Services Division
Lewis and Clark County - Septic Systems ↗Liberty County Health Department (County Sanitarian)
Montana DEQ - Homeowner's Guide to Septic Systems ↗Lincoln County Health Department (Environmental Health)
Lincoln County Health Department Environmental Health - Septic Application ↗Madison County Sanitarian / Environmental Health
Madison County - Septic System Information ↗McCone County Sanitarian / McCone County Health Department
McCone County On-Site Wastewater Treatment Regulations ↗Meagher County Sanitarian (contracted to Southwest Montana Consulting, Inc.)
Meagher County - Sanitarian Services ↗Mineral County Environmental Health and Planning
Mineral County Environmental Health and Planning ↗Missoula City-County Health Department (Missoula Public Health), Environmental Health
Missoula Public Health - Septic ↗Musselshell County Sanitation Services (County Sanitarian)
Musselshell County - Sanitation ↗Park County Environmental Health Department
Park County Environmental Health Department ↗Montana Department of Environmental Quality
Montana DEQ - Engineering, Infrastructure & Subdivisions ↗Phillips County Health Department
Phillips County Resource Guide (lists Phillips County Health Department) ↗Pondera County Sanitarian (delegated under Montana DEQ)
Pondera County - Sanitarian ↗Powder River County Sanitarian
Powder River County Sanitarian ↗Tri-County Environmental Health (Anaconda-Deer Lodge, Granite, Powell)
Powell County Tri-County Environmental Health ↗Prairie County Sanitarian / Health Department (shared with Dawson County, under Montana DEQ)
Prairie County Sanitarian ↗Ravalli County Environmental Health (RCEH)
Ravalli County Septic Permits ↗Richland County Health Department, Environmental Health Office
Richland County Environmental Health - Septic Systems ↗Roosevelt County Sanitarian
Roosevelt County Sanitarian ↗Rosebud County Sanitarian
Rosebud County - County Planner ↗Sanders County Environmental Health
Sanders County Environmental Health ↗Sheridan County Sanitarian / Environmental Health (DEQ-delegated)
Montana DEQ - Engineering, Infrastructure & Subdivisions ↗Butte-Silver Bow Environmental Health Division
Butte-Silver Bow Septic Permits and Information ↗Stillwater County Environmental Health Department
Stillwater County, MT Environmental Health ↗Sweet Grass County Environmental Health
Sweet Grass County Forms/Permits ↗Teton County Sanitarian
Teton County Montana - Septic System Permitting ↗Toole County Environmental Health / County Sanitarian
Toole County - Environmental Health and Sanitarian ↗Treasure County Sanitarian / Environmental Health (DEQ-delegated)
Montana DEQ - Engineering, Infrastructure & Subdivisions ↗Valley County Sanitation Department (County Sanitarian)
Valley County - Sanitarian ↗Wheatland County Environmental Health (County Sanitarian)
Wheatland County Environmental Health ↗Montana Department of Environmental Quality (DEQ)
Montana DEQ, Engineering Infrastructure & Subdivisions ↗RiverStone Health, Environmental Health Services (Yellowstone County local health department)
RiverStone Health - Septic Permits & Subdivision Review ↗Every county here has a full profile — its index score, water, land prices, and the rest of its building rules. See the Montana state page for all counties ranked, or the national septic guide.
General guidance, not legal advice. Off-grid, building, and land-use rules are often set at the county level and change often. Verify with your county and state before acting. Data reviewed 2026-06-26.
