On-Site Sewage Systems Setbacks

What’s Happening?

On March 6, 2026, the State Board of Health (board) initiated rulemaking to consider amending WAC 246-272A-0210 to clarify the minimum horizontal separations for surface water used as a public and nonpublic drinking water source. 

Why?

The board has the authority under RCW 43.20.050(3) to adopt rules for the design, construction, installation, operation, and maintenance of on-site sewage systems (OSS) with flows of less than 3,500 gallons per day. Chapter 246-272A WAC establishes the standards for these systems, and the Department of Health (department) implements the OSS program.

In March 2024, the board adopted the most recent revisions to chapter 246-272A WAC. Under this rulemaking, the minimum horizontal separations, or setbacks, in Table IV of WAC 246-272A-0210, were amended. The setback requirement for surface water used as a public drinking water source measured from the ordinary high-water mark was increased to proactively protect source water around surface water intakes.

In November 2025, the board received a petition for rulemaking. The petition described unintended consequences of the rule change, including limiting or prohibiting development along river systems regardless of where water is withdrawn for drinking water, and requested that the board change the setback for surface water used as a public drinking water source back to what it was in the previous version of the rule. The board accepted the petition.

This rulemaking project will explore changes to WAC 246-272A-0210 to clarify the minimum horizontal separations for surface water used as a public and nonpublic drinking water source. The board will also consider making a limited number of technical edits to correct errors discovered after implementation of the revised rule.

Get Involved

Informal Public Comment Period Deadline May 20, 2026

The board, in collaboration with the department, is requesting informal feedback on draft revisions to chapter 246-272A, On-site Sewage Systems.

The board held a workshop on April 9, 2026, with interested parties, including local health jurisdictions, the department, county officials, and others, to gather feedback on potential solutions to clarify the minimum horizontal separations for surface water used as a public and nonpublic drinking water source. The board is now gathering additional feedback from interested parties to continue to refine the draft rule language before developing a formal proposal.

Document to Review

Chapter 246-272A WAC Draft Changes (Word)
Please download the Word document to see the tracked changes.

Provide Feedback on Draft Changes

We are requesting feedback during this informal comment period on potential approaches to revising the setback requirements by May 20, 2026, at 11:59 p.m. An informal comment period is an opportunity to provide feedback before a formal proposal for rule language, and your participation is critical.

Written comments will be accepted until May 20, 2026, at 11:59 p.m., using the following options:

  1. Send to the State Board of Health email address: wsboh@sboh.wa.gov
  2. Send via U.S. Mail to:

Washington State Board of Health
PO Box 47990
Olympia, WA 98504-7990

Additional Comment Methods – The Washington State Board of Health is committed to providing access to all individuals who want to participate in our work. Alternative commenting options include verbal comment, support for interpretation and translation, and other accessible options. If you would like to take advantage of these methods of providing comment, please contact us at (360) 236-4110 or email wsboh@sboh.wa.gov.

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

Rulemaking Files

Document What's This? Date Filed
CR-101 – Preproposal Statement of Inquiry (PDF)  Announces intent of rulemaking March 6, 2026
Chapter 246-272A WAC Draft Changes (Word) Draft changes for informal public comment period. Comments are due by May 20, 2026. N/A

Contacts