The purpose of On-site Septic System (OSS) program is to ensure proper treatment and disposal of wastewater to protect our drinking water and the environment. We issue septic permits, inspect final septic installations, and investigate complaints associated with on-site sewage systems
Anyone who installs, alters, or repairs an on-site septic system is required to first obtain a permit from Chelan-Douglas Health District. Installation of a system requires site and soil evaluations to ensure an appropriate and adequate system is installed.
To apply for any for the following:
- New Construction – Septic System
- New Construction – Intermediate (>1000 gpd)
- Tank Replacement Only
- Project Review
- Permit Extension
- Soil Evaluation
- Private Water Review
- Septic Re-design
Please complete the Onsite Septic and Water Master Permit Application and return to the Chelan-Douglas Health District with the appropriate fees.
A step-by-step overview of the permitting process and design guidelines for conventional septic tank and drainfield systems is available.
Designing and Installing an On-Site Septic System
Private home owners are limited to designing and installing one conventional gravity onsite septic system for their own personal single family residence within a 12 month period. All other work related to the design, installation, maintenance, operation, and repair of all conforming and non-conforming onsite septic systems shall only be completed by an appropriately licensed and/or certified professional.
Operation and Maintenance
The Washington Administration Code, Chapter 246-272A-0270 details homeowner maintenance responsibilities for septic systems. Operation and maintenance (O&M) is about OSS functioning properly and being cared for correctly. In order for an OSS to continue to function properly, care must be taken by those responsible for it. Proper monitoring, correct operation and maintenance are the responsibility of the OSS owner.
OSS evaluations must be done by a licensed O&M Specialist. See the list of licensed qualified O&M providers to perform Operation and Maintenance on your septic system.
A Report is completed at the time of the evaluation by the O&M Specialist.
OSS evaluations should be performed once every three years for conventional gravity systems (systems consisting of only septic tank and drainfield) and annually for all other systems unless specified by the manufacturer.
More information on septic system operation and maintenance
- Caring for your Septic System
- Operation and Maintenance of Onsite Sewage Systems
- O&M General Information
- Service Provider Application
- O&M Study Guide
For Operation and Maintenance Providers: On-Site Sewage System Inspection Form
Requesting an As-Built
We also maintain As-Built records of existing on-site sewage systems. An As-Built is a drawing of a septic system as it was installed. If you would like to request a copy of an As-Built, please fill out our online Asbuilt Request Form.
Record Drawing (As-Built) form to be used after installation is completed. Please complete this form and return to the Chelan-Douglas Health District: Asbuilt Record Drawing Form