On-Site Sewage System Design Professionals

On-Site Sewage Systems

Designers of on-site sewage systems must have an On-site Wastewater Treatment System Designers license from the Department of Licensing to operate in Washington state.

View the process for license and subsequent inclusion on Designers List by clicking here.


To ease in understanding, the health district developed this process for potential designers.

Below is a higher-level description of this process.

In accordance with WAC 246-272A-0230, on-site sewage systems may only be designed by professional engineers, licensed under chapter 18.43 RCW, or on-site sewage treatment system designers, licensed under chapter 18.210 RCW. 

The health district does not license on-site sewage system design professionals or engineers, and does not verify license status on a continuous basis. To check the license status of a designer or engineer, visit the Washington State Department of Licensing website.

The health district maintains a list of licensed designers for convenience. It consists of individuals and companies that requested inclusion after being licensed. Spokane Regional Health District does not endorse, recommend, or warrant the work of any design professional or engineer.

Current Designers List (PDF)

Public Records
Public Records

Contact us to request a record

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