Bolthole Index county-legal census · checked 2026-10-09
Septic permitting in Montana is handled at the county level — county health departments approve systems in 47 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 56
Beaverhead County (Wastewater regulations, under Montana DEQ)
Beaverhead County Wastewater System Regulations ↗Big Horn County Public Health Department (County Sanitarian), under MT DEQ rules
Septic Permitting ↗Blaine County Environmental Health / Registered Sanitarian (Septic System Program)
Blaine County Environmental Health Sanitarian ↗Broadwater County Environmental Health
Environmental Health & Sanitarian ↗Carbon County Environmental Health Department (with Montana DEQ review for subdivisions under 20 acres)
Environmental Health - Carbon County ↗Carter County Sanitarian
Carter County, MT official website (Sanitarian) ↗Cascade City-County Health Department (CCHD)
Septic Systems & My Health Department Portal ↗Chouteau County Sanitarian / Chouteau County Public Health
Chouteau County Growth Policy 2017 ↗Custer County Environmental Health / Sanitarian (with Montana DEQ liaison)
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
Sanitation/Environmental Health – Fallon County ↗Fergus County Health Department (Environmental Health)
Health Department - Environmental Health ↗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
Environmental Health - Hill County Health Department ↗Jefferson County Environmental Health / Sanitarian
Environmental Health | Sanitarian - Jefferson County Montana ↗Central Montana Health District (Central MT Environmental Health)
Judith Basin County - Central MT Environmental Health ↗Lake County Board of Health / Environmental Health
Wastewater Treatment | Lake County, MT ↗Lewis and Clark Public Health, Environmental Services Division
Septic System Programs ↗Liberty County Health Department (County Sanitarian)
Public Notices | Liberty County MT ↗Lincoln County Health Department (Environmental Health)
Septic Permitting ↗Madison County Sanitarian / Environmental Health
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.)
Sanitarian Services ↗Mineral County Environmental Health and Planning
Environmental Health and Planning - Mineral County MT ↗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 Onsite Wastewater Treatment Regulations ↗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)
Sanitarian | Pondera County, Montana ↗Powder River County Sanitarian
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)
Sanitarian – County Of Prairie ↗Ravalli County Environmental Health (RCEH)
Environmental Health ↗Richland County Health Department, Environmental Health Office
Septic Systems in Richland County ↗Roosevelt County Sanitarian
Sanitarian ↗Rosebud County Sanitarian
County Planner - Rosebud County ↗Sanders County Environmental Health
Sanders County Wastewater Treatment Regulations ↗Sheridan County Sanitarian / Environmental Health (DEQ-delegated)
Montana DEQ - Engineering, Infrastructure & Subdivisions ↗Butte-Silver Bow Environmental Health Division
Septic Permits and Information ↗Stillwater County Environmental Health Department
How to Obtain a Septic Permit in Stillwater County ↗Sweet Grass County Environmental Health
Sweet Grass County Forms/Permits ↗Teton County Sanitarian
Sanitarian | Teton County Montana ↗Toole County Environmental Health / County Sanitarian
Environmental health and/sanitarian - Toole County ↗Treasure County Sanitarian / Environmental Health (DEQ-delegated)
Engineering Infrastructure & Subdivisions ↗Valley County Sanitation Department (County Sanitarian)
Sanitarian | Valley County, MT ↗Wheatland County Environmental Health (County Sanitarian)
Wheatland County Environmental Health ↗Montana Department of Environmental Quality (DEQ)
Engineering Infrastructure & Subdivisions | Montana DEQ ↗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.
Off-grid gear
Before the Montana septic office sees a parcel, you can test it yourself. What we'd bring:
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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.