Free testing, with limits
Free nitrate and bacteria testing in Washington is limited to parts of the Lower Yakima Valley and western Benton County. Check which tests it includes before you count on it for lead.
Washington's private well pageLead in Washington well water, by county
Lead is widespread, over the limit in 15% or more of tested wells, in 1 of the 15 Washington counties with 10 or more tested wells. A county's share tells you how likely a problem is nearby. Only a test of your own well tells you what's in it.
These tests sample the groundwater, and lead rarely comes from the ground. In a home it mostly comes from plumbing: old solder, brass fittings and some older pumps. So a county's share can't tell you about your pipes. Test a first-draw sample, water that sat in the pipes overnight, from the tap you drink from.
How Washington compares with the rest of the country
Across Washington, about 1 in 37 tested wells had lead over the EPA action level of 15 µg/L (13 of 483). Across all tested wells in the US it's under 1 in 50. So lead turns up in Washington wells about twice as often as in the country as a whole, and a test is worth adding even if your county isn't on the list below.
Why it matters: It harms children's growing brains. The CDC says no amount in a child's blood is known to be safe.
Lead in tested wells, county by county
Share of each county's tested wells with at least one result over the EPA action level of 15 µg/L. Counties need 10 or more tested wells to be listed. Widespread means 15% or more, worth checking 5 to 15%, rare under 5%.
| County | Wells tested | Wells over the limit | Level |
|---|---|---|---|
| Whatcom County | 29 | Widespread | |
| Stevens County | 115 | Worth checking | |
| Okanogan County | 44 | Rare | |
| Grant County | 38 | Rare | |
| Clark County | 35 | Rare | |
| Thurston County | 35 | Rare | |
| Franklin County | 28 | Rare | |
| King County | 26 | Rare | |
| Spokane County | 24 | Rare | |
| Kitsap County | 20 | Rare | |
| Kittitas County | 20 | Rare | |
| Pierce County | 16 | Rare | |
| Whitman County | 11 | Rare | |
| Adams County | 10 | Rare | |
| Ferry County | 10 | Rare |
10 more Washington counties have 1 to 9 tested wells for lead, too few to rate.
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Where to get your well tested for lead in Washington
A lab Washington certifies
Ask for lead by name. Results from a certified lab count for a home sale or a loan.
Labs certified by WashingtonA mail-in kit
Fill the bottles at your kitchen tap and mail them back. We mark the kits that include lead.
Compare kitsKeep reading about wells in Washington
- Well water testing in Washington: how to get tested and what turns up statewide
- Lead in well water: where it comes from, what it does and how to remove it
- Nitrate in Washington wells, by county
- Arsenic in Washington wells, by county
- Uranium in Washington wells, by county
- Manganese in Washington wells, by county
- Radon in Washington wells, by county
Questions people ask about lead in Washington
Is there lead in Washington well water?
Lead is widespread, over the limit in 15% or more of tested wells, in 1 of the 15 Washington counties with 10 or more tested wells. Across Washington, about 1 in 37 tested wells had lead over the EPA action level of 15 µg/L (13 of 483). Across all tested wells in the US it's under 1 in 50. So lead turns up in Washington wells about twice as often as in the country as a whole, and a test is worth adding even if your county isn't on the list below.
Where can I get my well tested for lead in Washington?
Free nitrate and bacteria testing in Washington is limited to parts of the Lower Yakima Valley and western Benton County. If that doesn't cover you, use a lab certified by Washington for drinking water, or a mail-in kit that includes lead from a certified lab.
See Washington's list of certified labs, or compare mail-in kits.
Where these numbers come from
- Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000. A well counts as over if any of its tests was over the EPA action level of 15 µg/L. Wells tested for studies and monitoring, not a random sample of homes.
- Likely overstated: our own check of who tested the wells, when and where. How we check.
- State programs and links: Department of Health (DOH); Department of Ecology for well records and lab accreditation.