On-site Sewage System Rule Revision

Chapter 246-272A WAC On-site Sewage Systems

Washington State Board of Health adopted proposed changes to chapter 246-272A, On-site Sewage Systems, on January 10, 2024. The adopted revisions incorporate recommendations from the Onsite Rule Revision Committee and other issues raised by interested parties. 

Based on input from interested parties, the On-site Sewage System rule becomes effective with a staggered timeline. 

  • Effective April 1, 2024: Changes to WAC 246-272A-0110
  • Effective February 1, 2025: Maintenance Service Provider approval requirement
  • Effective March 1, 2025: All provisions of the rule excluding changes to WAC 246-272A-0110, the Maintenance Service Provider approval requirement, and Property Transfer Inspection requirement
  • Effective February 1, 2027: Property Transfer Inspection requirement

Key changes to the rule include:

  • Local Management Plans 
  • Field Verification of Proprietary Products 
  • Property Transfer Inspection 
  • Remediation
  • Repairs
  • Minimum Lot Sizes
  • Approval of Maintenance Service Providers 

Supporting Documents

Chapter 246-272A WAC

CR-103P Final Rule (PDF)

Concise Explanatory Statement (PDF)

Key Draft Rule Changes (PDF)

Summary of Rule Changes (PDF)

Summary of Public Comments and Staff Responses and Recommendations (PDF)

Significant Analysis (PDF)

Small Business Economic Impact Statement (PDF)


March 2018, CR-101 Filed

May 2018, Formed Rule Revision Committee

June 2018 - August 2019, Rule Revision Committee Meetings 

August - October 2019, Informal Comment Period 

November 2019, State Board of Health Update 

October 2023, CR-102 Filed 

January 2024, State Board of Health Hearing & Public Hearing 

March 1, 2024, CR-103 Filed 

Rule Effective Dates, See staggered timeline above.

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Rule Revision Contacts

Peter Beaton, Rule Coordinator, 360-236-4031

Jeremy Simmons, Wastewater Program Manager, 360-236-3346