Issaquah continues to use a filtration system to address polyfluoroalkyl substances, or PFAS, detected in some of its well water.
Based on the latest science, the Environmental Protection Agency’s (EPA) recently released drinking water health advisories on two PFAS, called PFOA and PFOS. Issaquah water at the tap is below these advisories.
Issaquah participates in EPA’s unregulated contaminant monitoring program by performing additional tests on our drinking water. During that testing, detections of PFAS, were found in Well 4. In the winter of 2016, the City took proactive action and stopped running Well 4 until the filtration system was installed and tested.
Meanwhile, more stringent testing has been conducted to better understand the potential sources of PFAS in Issaquah.
Except for Well 4 (before treatment), all of Issaquah’s wells have tested below EPA’s detection thresholds for PFAS (.04 parts per billion for PFOS and .02 parts per billion for PFOA). Trace amounts have been detected in nearby Well 5 that are even below levels defined by EPA as an actual detection.**
Following a recent story published by Consumer Reports, Issaquah is inquiring about where their test was performed (as there are several water providers/systems in this area), and how. As their story states: “We can’t draw conclusions about any specific water system, because results from one location on a single day don’t necessarily reflect a system’s overall quality…”
We are consistently testing to ensure our water quality. Safety is our top priority – and Issaquah meets all standards set for safe drinking water. Learn more about Issaquah's water in our water quality report.
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** Updated April 29, 2021: Trace amounts have been detected in nearby Well 5 that are above levels defined by EPA as an actual detection, but remain below EPA's health advisories.