Septic Systems in Yakima County, WA

Regulations, costs, soil data & local providers

Pop. 256,728 ~15% on septic ~15,404 septic homes

Septic pumping in Yakima County, Washington costs $400-$750 (avg $550). A new septic system installation costs $7,650-$15,350. Approximately 15,404 homes in this county use septic systems.

Septic System Costs in Yakima County

ServiceLowAverageHigh
Pumping / Cleaning$400$550$750
Routine Inspection$300$400$550
Real Estate Inspection$500$750$1050
Minor Repair$950$1,350$6,700
Conventional Installation$7,650$10,950$15,350
Aerobic System Installation$14,400$20,550$28,750
Drainfield Replacement$7,650$10,950$15,350
Perc Test$1,150$1,650$2,300

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

Groundwater & Water Table in Yakima County

Monitoring Wells
117
Avg Depth to Water
85.4 ft
Median Depth
62.3 ft
Shallowest Recorded
3 ft Shallow Risk

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

Source: USGS National Water Information System. Based on 588 measurements from monitoring wells.

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

Septic System FAQ for Yakima County

How much does septic pumping cost in Yakima County?
Septic pumping in Yakima County, Washington typically costs between $400 and $750, with an average of $550. 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 Yakima County?
A conventional septic system installation in Yakima County typically costs $7,650-$15,350. An aerobic treatment unit (ATU) costs $14,400-$28,750. Costs include the tank, drainfield, permits, and labor.
Do I need a permit for a septic system in Yakima 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 Yakima County health department for current requirements and fees.
What soil types are in Yakima County and how do they affect septic systems?
Contact the county health department for soil evaluation requirements.
Is a septic inspection required when selling a home in Yakima 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 $750. 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 Yakima 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 15,404 septic systems in Yakima County, there are many local providers offering regular pumping services.
How long does a septic system last in Yakima County?
A well-maintained septic system in Yakima 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

Population256,728
Est. Septic Homes15,404
Avg Pumping Cost$550

Common Septic Services

Pumping: $400-$750
Inspection: $300-$550
Repair: $950-$6,700
Installation: $7,650-$15,350

Data last updated: 2026-04-13