Grays Harbor County Water Testing Lab
310 West Spruce Street
Montesano, WA 98563-2614
- Coliform bacteria
- Nitrate
Call to confirm the lab accepts private well samples, and ask about price and turnaround.
Well water testing in Grays Harbor County, Washington
Labs copied from the official Washington certified lab list (last verified 2026-10-29). All Washington labs
The official Washington list shows 1 certified lab in Grays Harbor County. Call before you sample to confirm the lab accepts private well water and to ask about bottles, prices and drop-off times.
Certified labs in Grays Harbor County
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What to test for
- Every year, test for total coliform bacteria, nitrate, total dissolved solids and pH, as EPA recommends for private wells. Source
- Nitrate: USGS finds higher nitrate in shallow groundwater under farmland. Parts of Washington are intensively farmed, so test nitrate every year, and before using the water for infant formula. Source
- Arsenic: USGS maps show naturally occurring arsenic in groundwater in parts of Washington and its region. Test at least once, then as your lab or health department advises. Source
- PFAS: test if you live near an airport, military base, landfill, or industrial or firefighting-foam site. EPA explains private well PFAS testing. Source
- After flooding, test for bacteria before drinking the water again, as EPA advises. Source
After a flood in Grays Harbor County
EPA says to test a private well for bacteria after flooding before drinking the water again. Check current flood alerts and Flood Watch, and read flood season testing. EPA: your well after a flood
Local help
Your Grays Harbor County or local health department can tell you about local well testing, including any free or low-cost programs. State contact: Washington State Department of Ecology (lab certification).
Questions
Where can I test well water in Grays Harbor County, WA?
The official Washington certified lab list shows 1 lab in Grays Harbor County; they are listed on this page with phone numbers. Call first to confirm they accept private well samples.
How often should I test my well?
EPA recommends testing every year for total coliform bacteria, nitrates, total dissolved solids and pH, and testing right away after flooding, well repairs, or a change in taste, color or smell.
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