Map of Arsenic Detections in Washington Public Water Supplies (PDF)
The public water system sources shown on the map have exceeded an arsenic level of 10 ppb (black dots) or 50 ppb (red dots) at least once over the sampling history for that source. This does not necessarily mean that an MCL (maximum contaminant level) was exceeded for the source since the current 10 ppb standard did not come into effect until January 2006. The data contained in the above map covers the time period from 1/1/1993 - 07/31/2007.
Contacts
For drinking water and statewide source monitoring questions, call your regional office.
Eastern Region, Spokane: 509-329-2100
Northwest Region, Kent: 253-395-6750
Southwest Region, Tumwater: 360-236-3030
Health effects of arsenic-contaminated water: Office of Environmental Public Health Sciences, 360-236-3385
Viable treatment technology options: Sophia Petro, Chemical Water Quality Monitoring Program, 564-669-0856