What's Happening?
We are considering a request for the 2026 legislative session to revise the definitions of a “public drinking water system” in RCW 70A.125.010 and WAC 246-290-020 and 246-291-010(51).
Why?
The current definitions of a public drinking water system in state law (RCW) and state rules (WAC) exclude systems “with four or fewer connections all of which serve residences on the same farm” without clarification between a Group A or Group B system.
This change is motivated by a formal request from the EPA to revise the definition of “public water system” to align with the EPA’s definition under the Safe Drinking Water Act 40 CFR Part 142. The definition in RCW and WAC needs to be as stringent as the Safe Drinking Water Act 40 CFR Part 142 to ensure all water systems that meet the threshold of 15 service connections or regularly serve an average of at least twenty-five individuals daily at least 60 days out of the year are regulated as Group A public water systems, without exception.
We need a change in legislation (RCW) to allow clarification in state rules (WAC). WAC 246.290.020(5)(c) and RCW 70.A.125(5) define a Group B public water system as a public water system that does not meet the definition of a Group A public water system. This rule revision will:
- Align state and federal definition of a public water system.
- Further clarify the difference between a Group A public water system and a Group B public water system.
- Provide exclusions only from a Group B public water system for four or fewer residential connections on the same farm.
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Environmental Justice Assessment
Proposing legislation changes is a significant agency action that requires the completion of an environmental justice assessment.
Proposed Timeline and Opportunities for Input!
Winter 2025
- Initiate environmental justice assessment.
- Identify communities and populations most impacted by this change.
Spring 2025
- Receive community input on the agency’s proposed changes.
Summer 2025
- Analyze community engagement and input. Identify additional outreach needs and opportunities.
- Develop proposed legislation changes and environmental justice assessment based on community engagement and input.
August 2025
- Submit proposed legislation changes to the Office of the Governor and Office of Financial Management for their consideration and approval.
If accepted: January 2026 – Provide input to the legislature on the agency’s proposed changes.
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