On-site Sewage System Technical Correction Rulemaking

WAC 246-272A-0110, Table I, Category 2, On-site Sewage Systems

Affected and Interested Parties

Companies that manufacture proprietary treatment products and other interested parties.

What’s Happening?

The Department of Health (Department) adopted a proposed change to WAC 246-272A-0110, Table 1, Category 2, on February 26, 2025. The adopted change adds NSF/ANSI 40 -Residential Wastewater Treatment Systems (versions dated between January 2009 and May 31, 2021) testing for Category 2 productsThe rule becomes effective on April 1, 2025.

Why?

Category 2 products treat high-strength sewage from restaurants and other facilities that generate high levels of oil and grease. Prior to the recent rule revision, the rule required testing for Category 2 products under the EPA/NSF Protocol for the Verification of Wastewater Treatment Technologies/EPA Environmental Technology Verification (April 2001). This protocol tested for biochemical oxygen demand (BOD5), total suspended solids (TSS), and oil and grease. EPA archived this testing protocol in 2013. During the recent rule revision of chapter 246-272A WAC, the EPA Method 1664, Revision B (February 2010) testing was adopted for Category 2 systems to treat oil and grease. This recommendation, however, neglected to assure that Category 2 products are also tested for carbonaceous biochemical oxygen should be tested by both EPA Method 1664, Revision B (February 2010) and NSF/ANSI 40 -Residential Wastewater Treatment Systems (versions dated between January demand (CBOD5) and TSS. The Department determined Category 2 products 2009 and May 31, 2021).  

Rulemaking Timeline 

May 2024 – Start rulemaking

July 2024 – Informal comment period

December 2024 – Formal comment period

December 18, 2024 - Public hearing

March 2025 – Rulemaking complete

Rulemaking Resources

Documents What's This Date Filed/Released
Documents CR-101 Preproposal Statement of Inquiry (PDF) What's This Announces intent of rulemaking. Date Filed/Released May 13, 2024
Documents CR-102 Proposed Rule (PDF) What's This Proposed Rulemaking Date Filed/Released November 6, 2024
Documents Significant Analysis (PDF) What's This Describes why the rule is needed Date Filed/Released  
Documents Small Business Economic Impact Statement (PDF) What's This Describes what a small business is likely to need in order to comply with the proposed rule. Date Filed/Released  
Documents CR-103 Adopted Rule (PDF) What's This Adopted Rule Date Filed/Released February 26, 2025
Documents Concise Explanatory Statement (PDF) What's This Summary of comments received during formal comment period Date Filed/Released  

Rule Revision Contacts

Katitza Holthaus, Regulatory Affairs Manager

Jeremy Simmons, Wastewater Section Manager