On-Site Sewage Systems Setbacks

Summary

Chapter 246-272A WAC discusses how to handle on-site sewage systems (OSS). It sets rules for where to put them and how to design, install, use, maintain, and manage them. The Washington State Board of Health filed a CR-101 on March 6, 2026. This statement explores changing the rules.

For More Information

Statutory Authority: RCW 43.20.050, RCW 70A.105, RCW 70A.110, RCW 43.20.065
State Board of Health Contact: Shay Bauman, shay.bauman@sboh.wa.gov
Department of Health Contact: Kseniya Efremova, kseniya.efremova@doh.wa.gov or Heather Watts-Goodfellow, heather.watts-goodfellow@doh.wa.gov

The Board will use an interested parties list for this rulemaking to provide updates and share information about opportunities to be engaged in the rule change. To join the interested parties list, fill out the OSS Setbacks interest form online.  

For more information on these rulemakings visit the Department of Health's rulemaking webpage.

Additional Background

In 2024, the State Board of Health (Board) adopted revisions to Chapter 246-272A WAC, which included changes to the minimum horizontal separation distances (setbacks) in Table IV of WAC 246-272A-0210. Specifically, the setback between on-site sewage system components and surface water used as a public drinking water source increased from 100 feet to 200 feet to proactively protect source water near drinking water intakes.

Following implementation, local health jurisdictions identified unintended consequences. The rule, as written, applies the increased setback along entire river systems, regardless of where the drinking water intake is located. This was not the intent of the rule change.

In November 2025, the Board received a formal petition for rulemaking from the Vice Chair of the Northeast Tri County Board of Health, requesting that the setbacks for surface water used as a public drinking water source be reverted to the prior requirements. The petitioners noted that the rule was impacting the ability to develop existing lots along the Pend Oreille River system, where properties may be miles upstream from any drinking water intake but are still subject to the new setback distances.

The Board accepted the petition at its January 14, 2026, meeting and agreed to initiate rulemaking. This rulemaking will explore clarifying the setback requirements in WAC 246-272A-0210 as they relate to both public and nonpublic drinking water sources. The Board will also consider a limited number of technical corrections to address drafting errors identified in several sections of Chapter 246-272A WAC following the 2024 implementation.

Tentative Rulemaking Timeline

  • March 2026 – Start rulemaking
  • May 2026 – Informal comment period
  • September-November 2026 – Formal comment period
  • November 2026 - Public hearing
  • December 2026 – Rulemaking complete

Below are Code Reviser filings for this rulemaking.

Related Links

January 14, 2026, Board Meeting