PFAS in Drinking Water—Monitoring and Analysis

The State Board of Health recently revised the Group A drinking water rules to require water systems to monitor for select per- and polyfluoroalkyl substances (PFAS) compounds using specific analytical methods. The new rule establishes state action levels (SALs) for five PFAS compounds.

For general information on PFAS, visit the DOH PFAS Contaminant webpage.

PFAS FAQ 331-681 (PDF)

State Monitoring Requirements for PFAS

Group-A Community and non-transient non-community (NTNC) water systems are required to monitor for PFAS beginning January 2023 through December 2025. Each water system's Water Quality Monitoring Schedule lists the PFAS monitoring requirement starting in 2023. PFAS Monitoring and Follow Up Actions 331-668 outlines the monitoring requirements in the revised rule.

Systems must collect samples at the entry point to the distribution system and have them analyzed by EPA Method 537.1 or 533 by a lab accredited for these analytes in Washington State.

Transient non-community (TNCs) systems may be required to monitor if their source of supply is near a known PFAS contaminated site. ODW will notify affected TNCs when more information is known.

Free PFAS Analysis Offered

DOH has a free-PFAS sample program for Community and NTNC systems that will continue through early in 2022. Results count toward the state-required monitoring that would otherwise be scheduled in 2023-2025.

For water systems not currently signed up to participate in this sampling program, you can still sign up by submitting you information via our online form at Department of Health, Office of Drinking Water PFAS Free Sampling Enrollment Form. 

Systems with detections must collect follow-up samples and comply with the rule requirements.

Funding is limited and we may prioritize systems based on risk if volunteers exceed available funding.

State Action Levels

The SALs represent the maximum level in tap water that DOH considers to be without health concern for long-term consumption in daily drinking water, including by sensitive groups.

Specific PFAS Contaminant State Action Level (parts per trillion)
PFHxS 65
PFBS 345

Exceeding a State Action Level (SAL) for PFAS

Systems with a PFAS sample result that exceeds a SAL should collect a confirmation sample. If the average results of the initial and confirmation samples exceed the SAL, or if the system doesn't collect a confirmation sample, the system must notify its customers of the SAL exceedance event. Use the public notification templates below.

Public Notice PFAS Detection 331-683 (Word)

More Resources

Regional Office Contacts for Monitoring Requirements

Eastern Region, Anna Duron, 509-329-2145

Northwest Region, Vacant,, 253-395-6750

Southwest Region, Sophia Petro, 564-669-0856

Funding for PFAS Mitigation

The federal Bipartisan Infrastructure Law make additional funding available in grants and loans to public water systems for PFAS treatment, new source, or another preferred option for mitigating PFAS contamination. If interested, email