Septic Systems in Jefferson County, MT

Regulations, costs, soil data & local providers

Pop. 12,085 ~35% on septic ~1,692 septic homes

Septic pumping in Jefferson County, Montana costs $300-$650 (avg $450). A new septic system installation costs $6,350-$12,750. Approximately 1,692 homes in this county use septic systems.

Septic System Costs in Jefferson 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 Jefferson County, Montana. Actual costs depend on system type, site conditions, and provider.

Groundwater & Water Table in Jefferson County

Monitoring Wells
4
Avg Depth to Water
33.7 ft
Median Depth
27.5 ft
Shallowest Recorded
15.3 ft

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

Source: USGS National Water Information System. Based on 24 measurements from monitoring wells.

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

Septic System FAQ for Jefferson County

How much does septic pumping cost in Jefferson County?
Septic pumping in Jefferson 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 Jefferson County?
A conventional septic system installation in Jefferson 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 Jefferson 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 Jefferson County health department for current requirements and fees.
What soil types are in Jefferson 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 Jefferson 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.
How long does a septic system last in Jefferson County?
A well-maintained septic system in Jefferson 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

Population12,085
Est. Septic Homes1,692
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