Septic pumping in Missoula County, Montana costs $350-$700 (avg $500). A new septic system installation costs $6,700-$13,450. Approximately 8,868 homes in this county use septic systems.
Septic System Costs in Missoula County
| Service | Low | Average | High |
|---|---|---|---|
| Pumping / Cleaning | $350 | $500 | $700 |
| Routine Inspection | $250 | $350 | $500 |
| Real Estate Inspection | $450 | $650 | $900 |
| Minor Repair | $850 | $1,200 | $5,900 |
| Conventional Installation | $6,700 | $9,600 | $13,450 |
| Aerobic System Installation | $12,600 | $18,000 | $25,200 |
| Drainfield Replacement | $6,700 | $9,600 | $13,450 |
| Perc Test | $1,000 | $1,450 | $2,050 |
Cost estimates based on regional market data for Missoula County, Montana. Actual costs depend on system type, site conditions, and provider.
Groundwater & Water Table in Missoula County
Monitoring Wells
6
Avg Depth to Water
9.1 ft
Median Depth
10.5 ft
Shallowest Recorded
4.4 ft
Moderate water table depth. Some sites may require modified systems or mound systems.
Source: USGS National Water Information System. Based on 229 measurements from monitoring wells.
Septic Regulations & Permits in Missoula 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 Missoula County health department for current permit requirements, fees, and approved system types.
Septic System FAQ for Missoula County
How much does septic pumping cost in Missoula County?
Septic pumping in Missoula County, Montana typically costs between $350 and $700, with an average of $500. 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 Missoula County?
A conventional septic system installation in Missoula County typically costs $6,700-$13,450. An aerobic treatment unit (ATU) costs $12,600-$25,200. Costs include the tank, drainfield, permits, and labor.
Do I need a permit for a septic system in Missoula 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 Missoula County health department for current requirements and fees.
What soil types are in Missoula County and how do they affect septic systems?
Contact the county health department for soil evaluation requirements.
How often should I pump my septic tank in Missoula 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. With approximately 8,868 septic systems in Missoula County, there are many local providers offering regular pumping services.
Does the water table in Missoula County affect septic systems?
Yes. The average groundwater depth in Missoula County is approximately 9.1 feet, based on USGS monitoring data from 6 wells. While this is sufficient for many conventional systems, sites with lower elevations or seasonal water table fluctuations may require alternative system designs. A site-specific evaluation is always recommended.
How long does a septic system last in Missoula County?
A well-maintained septic system in Missoula 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. Regular pumping every 3-5 years and avoiding excess water usage are the two most effective ways to extend system life.
Data last updated: 2026-04-13