Septic Systems in Silver Bow County, MT

Regulations, costs, soil data & local providers

Pop. 35,133 ~30% on septic ~4,216 septic homes

Septic pumping in Silver Bow County, Montana costs $300-$650 (avg $450). A new septic system installation costs $6,350-$12,750. Approximately 4,216 homes in this county use septic systems.

Septic System Costs in Silver Bow County

ServiceLowAverageHigh
Pumping / Cleaning$300$450$650
Routine Inspection$250$350$500
Real Estate Inspection$450$650$900
Minor Repair$800$1,150$5,600
Conventional Installation$6,350$9,100$12,750
Aerobic System Installation$11,950$17,100$23,950
Drainfield Replacement$6,350$9,100$12,750
Perc Test$950$1,350$1,900

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

Groundwater & Water Table in Silver Bow County

Monitoring Wells
2
Avg Depth to Water
4.6 ft
Median Depth
4.7 ft
Shallowest Recorded
0.6 ft Shallow Risk

Moderate water table depth. Some sites may require modified systems or mound systems.

Source: USGS National Water Information System. Based on 111 measurements from monitoring wells.

Septic Regulations & Permits in Silver Bow 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 Silver Bow County health department for current permit requirements, fees, and approved system types.

Septic System FAQ for Silver Bow County

How much does septic pumping cost in Silver Bow County?
Septic pumping in Silver Bow 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 Silver Bow County?
A conventional septic system installation in Silver Bow County typically costs $6,350-$12,750. An aerobic treatment unit (ATU) costs $11,950-$23,950. Costs include the tank, drainfield, permits, and labor.
Do I need a permit for a septic system in Silver Bow 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 Silver Bow County health department for current requirements and fees.
What soil types are in Silver Bow 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 Silver Bow 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.
Does the water table in Silver Bow County affect septic systems?
Yes. The average groundwater depth in Silver Bow County is approximately 4.6 feet, based on USGS monitoring data from 2 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 Silver Bow County?
A well-maintained septic system in Silver Bow 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.

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Quick Facts

Population35,133
Est. Septic Homes4,216
Avg Pumping Cost$450

Common Septic Services

Pumping: $300-$650
Inspection: $250-$500
Repair: $800-$5,600
Installation: $6,350-$12,750

Data last updated: 2026-04-13