Does a detection mean the water is unsafe or out of compliance?

No. UCMR 5 is monitoring data and does not indicate compliance or noncompliance with any drinking-water standard. It reports the highest single detected result at the entry point, which is information you can act on by testing your own tap and choosing a certified filter.

PFAS detected in Washington water systems

Q: Which Washington water systems had PFAS detected in EPA UCMR 5?

EPA UCMR 5 detected PFOA or PFOS at or above 6 parts per trillion in 15 large Washington public water systems (each serving more than 10,000 people). Select a system to see the specific PFAS and highest levels detected.

EPA UCMR 5 monitoring (2023–2025) detected PFOA or PFOS at or above 6 parts per trillion in these 15 large Washington public water systems, each serving more than 10,000 people. Select a system to see exactly what was detected and the certified filters that reduce it.

Washington systems, highest detections first

Water system	PFOA (ppt)	PFOS (ppt)	vs. 4 ppt reference
Moses Lake City of	—	52.2	13.1×
Vancouver City of	11.5	18.6	4.7×
Richland City of	10.1	17	4.3×
Parkland Light & Water Company	6.2	13.8	3.5×
Camas Municipal Water Sewer System	4.4	12	3×
Kennewick City of	4.6	11.5	2.9×
JBLM Lewis	6.8	11.1	2.8×
Sammamish Plateau Water & Sewer	—	11.1	2.8×
Southwood Water System	6.2	8.9	2.2×
Covington Water District	—	8.6	2.1×
Firgrove Mutual Inc	4.4	8.6	2.1×
Clark Public Utilities	8	8.4	2.1×
Spanaway Water Company	6.2	8.3	2.1×
Washougal City of	—	7.9	2×
Spokane City of	—	6.1	1.5×

Highest single EPA UCMR 5 detections (2023–2025), in parts per trillion. The last column is the multiple of the 4 ppt federal reference level for PFOA/PFOS — shown as context only, not a compliance or health determination. — means the compound was not detected at or above 6 ppt.

Not sure what's in your own water? Test it first, then run the selector for a recommendation matched to your home, or read what PFAS is and how it's removed.