Septic Systems in Cascade County, MT

Regulations, costs, soil data & local providers

Pop. 84,414 ~25% on septic ~8,441 septic homes

Septic pumping in Cascade County, Montana costs $350-$700 (avg $500). A new septic system installation costs $6,700-$13,450. Approximately 8,441 homes in this county use septic systems.

Septic System Costs in Cascade County

ServiceLowAverageHigh
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 Cascade County, Montana. Actual costs depend on system type, site conditions, and provider.

Groundwater & Water Table in Cascade County

Monitoring Wells
1
Avg Depth to Water
137.6 ft
Median Depth
137.5 ft
Shallowest Recorded
137.4 ft

Water table depths in this county are generally favorable for conventional septic systems.

Source: USGS National Water Information System. Based on 10 measurements from monitoring wells.

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

Septic System FAQ for Cascade County

How much does septic pumping cost in Cascade County?
Septic pumping in Cascade 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 Cascade County?
A conventional septic system installation in Cascade 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 Cascade 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 Cascade County health department for current requirements and fees.
What soil types are in Cascade 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 Cascade 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 8,441 septic systems in Cascade County, there are many local providers offering regular pumping services.
How long does a septic system last in Cascade County?
A well-maintained septic system in Cascade 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

Population84,414
Est. Septic Homes8,441
Avg Pumping Cost$500

Common Septic Services

Pumping: $350-$700
Inspection: $250-$500
Repair: $850-$5,900
Installation: $6,700-$13,450

Data last updated: 2026-04-13