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 uranium.
Washington's private well pageUranium in Washington well water, by county
Uranium is widespread, over the limit in 15% or more of tested wells, in 1 of the 9 Washington counties with 10 or more tested wells. 1 more look high, but those results likely overstate it. 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.
How Washington compares with the rest of the country
Across Washington, about 1 in 7 tested wells had uranium over the EPA limit of 30 µg/L (36 of 245). Across all tested wells in the US it's about 1 in 22. So uranium turns up in Washington wells about 3 times 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: Drinking it for years can harm your kidneys and raises the risk of cancer.
Uranium comes out of the rock and sediment the wells draw from.
Uranium in tested wells, county by county
Share of each county's tested wells with at least one result over the EPA limit of 30 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 |
|---|---|---|---|
| Stevens County | 44 | Widespread | |
| Franklin County | 28 | Widespread | |
| Grant County | 38 | Worth checking | |
| Spokane County | 24 | Rare | |
| Kittitas County | 20 | Rare | |
| Whatcom County | 18 | Rare | |
| Pierce County | 16 | Rare | |
| Whitman County | 11 | Rare | |
| Adams County | 10 | Rare |
* Likely overstated. These shares come from a narrow set of wells, so they probably run high for the county as a whole:
- Stevens County: Almost all of these tests come from a single agency in one small part of the county, so this likely overstates it.
14 more Washington counties have 1 to 9 tested wells for uranium, too few to rate.
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Where to get your well tested for uranium in Washington
A lab Washington certifies
Ask for uranium 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 uranium.
Compare kitsKeep reading about wells in Washington
- Well water testing in Washington: how to get tested and what turns up statewide
- Uranium 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
- Manganese in Washington wells, by county
- Lead in Washington wells, by county
- Radon in Washington wells, by county
Questions people ask about uranium in Washington
Is there uranium in Washington well water?
Uranium is widespread, over the limit in 15% or more of tested wells, in 1 of the 9 Washington counties with 10 or more tested wells. 1 more look high, but those results likely overstate it. Across Washington, about 1 in 7 tested wells had uranium over the EPA limit of 30 µg/L (36 of 245). Across all tested wells in the US it's about 1 in 22. So uranium turns up in Washington wells about 3 times 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 uranium 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 uranium 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 limit of 30 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.