Septic Systems in Stevens County, WA

Regulations, costs, soil data & local providers

Pop. 46,445 ~24% on septic ~4,459 septic homes Well drained soil

Septic pumping in Stevens County, Washington costs $350-$700 (avg $500). A new septic system installation costs $6,900-$13,800. USDA soil data rates 0.3% of county soils as suitable for septic absorption fields. Approximately 4,459 homes in this county use septic systems.

Septic System Costs in Stevens County

ServiceLowAverageHigh
Pumping / Cleaning$350$500$700
Routine Inspection$250$350$500
Real Estate Inspection$500$700$1000
Minor Repair$900$1,250$6,000
Conventional Installation$6,900$9,850$13,800
Aerobic System Installation$12,900$18,450$25,850
Drainfield Replacement$6,900$9,850$13,800
Perc Test$1,050$1,500$2,100

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

Soil & Septic Suitability in Stevens County

Drainage Class
Well drained
Hydrologic Group
C
Unique Soil Types
131
Avg Bedrock Depth
2.4 ft

Dominant Soil Types

Soil SeriesCoverageDrainageHydro Group
Spokane 790 Well drained C
Aits 766 Well drained B
Donavan 699 Well drained B
Stevens 680 Well drained D
Bernhill 635 Well drained B

Septic Tank Absorption Field Suitability

USDA NRCS rates soil suitability for septic absorption fields across this county:

Not Limited (Good)0.3%
Somewhat Limited4.9%
Very Limited94.7%

Overall rating: Very limited

Source: USDA NRCS Soil Survey Geographic Database (SSURGO)

Septic Regulations & Permits in Stevens County

State Regulatory Body
Washington State Department of Health
Inspection Required for Home Sale
Yes
Nitrogen Reduction Areas
Yes
Advanced Treatment Required
In designated areas

Mandatory time-of-sale inspection since 2008.

Contact the Stevens County health department for current permit requirements, fees, and approved system types.

Septic System FAQ for Stevens County

How much does septic pumping cost in Stevens County?
Septic pumping in Stevens County, Washington 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 Stevens County?
A conventional septic system installation in Stevens County typically costs $6,900-$13,800. An aerobic treatment unit (ATU) costs $12,900-$25,850. Given the predominantly well drained soils in this area, some sites may require alternative system types. Costs include the tank, drainfield, permits, and labor.
Do I need a permit for a septic system in Stevens County?
Yes. Virtually all counties in Washington 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 Stevens County health department for current requirements and fees.
What soil types are in Stevens County and how do they affect septic systems?
Stevens County has predominantly Spokane, Aits, Donavan soils. The dominant drainage class is Well drained with hydrologic group C. The USDA rates 0.3% of surveyed soils as "Not Limited" for septic absorption fields, 4.9% as "Somewhat Limited", and 94.7% as "Very Limited".
Is a septic inspection required when selling a home in Stevens County?
Yes. Washington requires a septic system inspection as part of the property transfer process. This typically involves a certified inspector evaluating the tank, drainfield, and all system components. The inspection cost in this area averages $700. If the system fails inspection, repairs or replacement may be required before the sale can proceed.
How often should I pump my septic tank in Stevens 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 Washington have mandatory pumping schedules — check with your local health department.
Can I install a conventional septic system in Stevens County?
It depends on your specific site. USDA soil data shows that 94.7% of soils in Stevens County are rated "Very Limited" for septic absorption fields, while only 0.3% are "Not Limited." This means many properties will require alternative systems such as mound systems, pressure distribution systems, or aerobic treatment units. A percolation test ($1050-$2100) and soil evaluation are required before the county will approve a system design.
How long does a septic system last in Stevens County?
A well-maintained septic system in Stevens 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 (Stevens County has predominantly well drained soils). 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

Population46,445
Est. Septic Homes4,459
Avg Pumping Cost$500
Drainage ClassWell drained
Septic SuitabilityVery limited

Common Septic Services

Pumping: $350-$700
Inspection: $250-$500
Repair: $900-$6,000
Installation: $6,900-$13,800

Data last updated: 2026-04-13