On-Site Sewage Systems

Septic systems, also known as On-site Sewage Systems (OSS), treat sewage so it does not contaminate local rivers, lakes, and groundwater. Just like your home or car, your septic system needs to be monitored and maintained regularly. Routine maintenance can reduce the chance of having to do major, costly repairs to your system, because small issues will be caught before they become larger problems.

The OSS program at the Walla Walla County Department of Community Health exists to ensure that on-site sewage disposal systems are properly designed and installed to prevent public exposure to sewage and to protect ground and surface water from contamination.

We have regulatory oversight for all domestic on-site sewage systems that are under 3500 gallons in Walla Walla County. We perform a wide variety of activities to carry out this oversight that include:

  • Site and Soil Evaluations
  • Application review for new, repaired or expanded On-Site Sewage Systems
  • Permit Issuance
  • Final construction inspections
  • Homeowner education and notification regarding proper Operation and Maintenance of their OSS
  • Enforcement of OSS Codes, including the Walla Walla County Ordinance Chapter 8.16 and   Washington Administrative Code, WAC 246-272A
  • Complaint investigations
  • Subdivision, Boundary Line Adjustment and Conditional Use review