Onsite Permitting Process

Before an On-site Sewage System (OSS) permit can be issued, there are several items that need to be done. To ensure this process goes quick and smooth we recommend the following steps:

  • Contact the Walla Walla Department of Community Health (WWCDCH) at (509) 524-2650 to schedule a site visit and test hole evaluation. Please note before any site visit can be done, the Site Evaluation Application and fee will need to be paid.  The site evaluation will determine if, where, and what type of OSS can be installed on the property.  To have a test hole evaluation done, the property owner or installer will have to schedule a site evaluation with an Environmental Health Specialist from the WWCDCH and coordinate with a backhoe operator to dig at least one hole that is 6-7 feet deep. If test holes are dug prior to our arrival than they must be dug and constructed in accordance to the Washington State Department of Health’s Guidelines for Test Pit Construction.  More test holes may be required per Environmental Health Specialist discretion.
  • When building in the Lewis Peak area, monitoring ports will be required during the wet season to monitor the seasonal high-water table. If building in this area a permit will not be issued until wet season monitoring is completed.  A $500 monitoring port fee will be required for this process.
  • Note: Effective July 1, 2023, All onsite sewage systems must be designed by a licensed On-Site Sewage System Designer or Professional Engineer, a list of these professionals operating within Walla Walla County can be obtained by clicking here Please note your permit application will not be approved until the design is approved by WWCDCH.
  • Fill out and submit the On-Site Sewage Application and pay the appropriate fee. 
  • Contact an On-site Sewage Licensed Installer for cost and installation information.