Septic Systems in Cassia County, ID

Regulations, costs, soil data & local providers

Pop. 24,655 ~26.4% on septic ~2,604 septic homes

Septic pumping in Cassia County, Idaho costs $300-$650 (avg $450). A new septic system installation costs $6,100-$12,200. Approximately 2,604 homes in this county use septic systems.

Septic System Costs in Cassia County

ServiceLowAverageHigh
Pumping / Cleaning$300$450$650
Routine Inspection$250$350$500
Real Estate Inspection$400$600$850
Minor Repair$750$1,100$5,300
Conventional Installation$6,100$8,700$12,200
Aerobic System Installation$11,450$16,350$22,900
Drainfield Replacement$6,100$8,700$12,200
Perc Test$900$1,300$1,800

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

Groundwater & Water Table in Cassia County

Monitoring Wells
94
Avg Depth to Water
197.3 ft
Median Depth
163.6 ft
Shallowest Recorded
4.2 ft

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

Source: USGS National Water Information System. Based on 173 measurements from monitoring wells.

Septic Regulations & Permits in Cassia County

State Regulatory Body
Idaho 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 Cassia County health department for current permit requirements, fees, and approved system types.

Septic System FAQ for Cassia County

How much does septic pumping cost in Cassia County?
Septic pumping in Cassia County, Idaho 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 Cassia County?
A conventional septic system installation in Cassia County typically costs $6,100-$12,200. An aerobic treatment unit (ATU) costs $11,450-$22,900. Costs include the tank, drainfield, permits, and labor.
Do I need a permit for a septic system in Cassia County?
Yes. Virtually all counties in Idaho 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 Cassia County health department for current requirements and fees.
What soil types are in Cassia 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 Cassia 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 Idaho have mandatory pumping schedules — check with your local health department.
How long does a septic system last in Cassia County?
A well-maintained septic system in Cassia 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

Population24,655
Est. Septic Homes2,604
Avg Pumping Cost$450

Common Septic Services

Pumping: $300-$650
Inspection: $250-$500
Repair: $750-$5,300
Installation: $6,100-$12,200

Data last updated: 2026-04-13