Codes and Regulations
The activities of the On-Site Sewage Program are governed by the Washington State and Mason County Codes and Regulations. For more information, click on the following links.
Mason County On-Site Regulations & Standards
- Mason County On-site Regulations (Effective Jan. 1st, 2022)
- Mason County On-Site Standards (Effective Jan. 1st, 2022)
- Mason County Environmental Health Building Permit Policies (Effective Jan. 24th, 2023)
Washington Administrative Code (WAC)
- Chapter 246-272A WAC, On-site Sewage Systems
- Chapter 246-272C WAC, On-site Sewage System Tanks
- Chapter 246-273 WAC, On-site Sewage System Additives
Revised Code of Washington (RCW)
- Chapter 43.20.050 RCW, State Board of Health-Delegation of Authority
- Chapter 43.70.310 RCW, Cooperation with Department of Ecology
- Chapter 70.118 RCW, On-site Sewage Disposal Systems
- Chapter 70.118A RCW, On-site Sewage Disposal Systems - Marine Recovery