Septic Systems in Treasure County, MT

Regulations, costs, soil data & local providers

Pop. 762 ~40% on septic ~122 septic homes Well drained soil

Septic pumping in Treasure County, Montana costs $300-$650 (avg $450). A new septic system installation costs $6,050-$12,100. USDA soil data rates 0.6% of county soils as suitable for septic absorption fields. Approximately 122 homes in this county use septic systems.

Septic System Costs in Treasure County

ServiceLowAverageHigh
Pumping / Cleaning$300$450$650
Routine Inspection$200$300$400
Real Estate Inspection$400$600$850
Minor Repair$750$1,100$5,300
Conventional Installation$6,050$8,650$12,100
Aerobic System Installation$11,350$16,200$22,700
Drainfield Replacement$6,050$8,650$12,100
Perc Test$900$1,300$1,800

Cost estimates based on regional market data for Treasure County, Montana. Actual costs depend on system type, site conditions, and provider.

Soil & Septic Suitability in Treasure County

Drainage Class
Well drained
Hydrologic Group
C
Unique Soil Types
71
Avg Bedrock Depth
2 ft

Dominant Soil Types

Soil SeriesCoverageDrainageHydro Group
Havre 1341 Somewhat poorly drained B
Lohmiller 1009 Well drained C
Cherry 996 Well drained C
Glendive 789 Somewhat excessively drained A
Nunn 665 Well drained C

Septic Tank Absorption Field Suitability

USDA NRCS rates soil suitability for septic absorption fields across this county:

Not Limited (Good)0.6%
Somewhat Limited21%
Very Limited78.3%

Overall rating: Very limited

Source: USDA NRCS Soil Survey Geographic Database (SSURGO)

Septic Regulations & Permits in Treasure County

State Regulatory Body
Montana Department of Health/Environment
Inspection Required for Home Sale
No / Varies
Nitrogen Reduction Areas
No
Advanced Treatment Required
No

Contact county health department for specific requirements.

Contact the Treasure County health department for current permit requirements, fees, and approved system types.

Septic System FAQ for Treasure County

How much does septic pumping cost in Treasure County?
Septic pumping in Treasure County, Montana typically costs between $300 and $650, with an average of $450. Costs vary by tank size (1,000-1,500 gallons is typical), ease of access, distance from the pumping company, and how full the tank is. Most homeowners should pump their tank every 3-5 years.
How much does a new septic system cost in Treasure County?
A conventional septic system installation in Treasure County typically costs $6,050-$12,100. An aerobic treatment unit (ATU) costs $11,350-$22,700. Given the predominantly well drained soils in this area, some sites may require alternative system types. Costs include the tank, drainfield, permits, and labor.
Do I need a permit for a septic system in Treasure County?
Yes. Virtually all counties in Montana require a permit before installing, repairing, or replacing a septic system. The permit process typically involves a soil evaluation or percolation test, system design by a licensed professional, application to the county health department, and one or more inspections during installation. Contact the Treasure County health department for current requirements and fees.
What soil types are in Treasure County and how do they affect septic systems?
Treasure County has predominantly Havre, Lohmiller, Cherry soils. The dominant drainage class is Well drained with hydrologic group C. The USDA rates 0.6% of surveyed soils as "Not Limited" for septic absorption fields, 21% as "Somewhat Limited", and 78.3% as "Very Limited".
How often should I pump my septic tank in Treasure County?
The EPA recommends pumping your septic tank every 3-5 years for a typical household. The exact frequency depends on tank size, household size, and water usage. A 1,000-gallon tank serving a family of 4 should generally be pumped every 3 years. Some counties in Montana have mandatory pumping schedules — check with your local health department.
Can I install a conventional septic system in Treasure County?
It depends on your specific site. USDA soil data shows that 78.3% of soils in Treasure County are rated "Very Limited" for septic absorption fields, while only 0.6% are "Not Limited." This means many properties will require alternative systems such as mound systems, pressure distribution systems, or aerobic treatment units. A percolation test ($900-$1800) and soil evaluation are required before the county will approve a system design.
How long does a septic system last in Treasure County?
A well-maintained septic system in Treasure County typically lasts 25-30 years, though some components may need attention sooner. The concrete septic tank itself can last 40+ years, while the drainfield — the most critical and expensive component — usually lasts 15-25 years depending on soil conditions (Treasure County has predominantly well drained soils). Regular pumping every 3-5 years and avoiding excess water usage are the two most effective ways to extend system life.

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Quick Facts

Population762
Est. Septic Homes122
Avg Pumping Cost$450
Drainage ClassWell drained
Septic SuitabilityVery limited

Common Septic Services

Pumping: $300-$650
Inspection: $200-$400
Repair: $750-$5,300
Installation: $6,050-$12,100

Data last updated: 2026-04-13