The Thurston County water lab is part of Thurston County Public Health and Social Services, at 412 Lilly Road NE in Olympia. Its page covers drinking water testing and well disinfection and does not limit testing to public systems.
Tests. Total coliform and E. coli presence/absence and nitrate for drinking water. Bacteria counts (total coliform and E. coli, fecal coliform or enterococci) are also available.
Prices. Fees published on the county’s water lab page (viewed 2026-10-24): coliform/E. coli presence/absence $32, nitrate $32, bacteria count $40.
Bottles and drop-off.
- Pick up bottles at 412 Lilly Road NE, Monday to Friday 9am to 4pm, at The Atrium (3000 Pacific Ave SE, Suite 225), or at satellite sites in Mason County, Rainier, Tenino, Rochester and Yelm.
- Drop off coliform samples Monday to Wednesday 9am to 4pm or Thursday 8am to 12:30pm, and nitrate samples on Tuesdays, at the Lilly Road front counter. An outside mailbox there takes samples during set hours.
- The Atrium stopped accepting sample drop-off in January 2026.
- The county lists closures in November and December 2026, so check the page before sampling.
Accreditation. Ecology accreditation H518 (current certificate H518-26), covering coliform and E. coli and nitrate in drinking water. The Department of Health lists the lab for nitrate and coliform testing of private wells.