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Getting your well water tested in Oregon

Use a lab Oregon certifies, or a mail-in kit. Across the state, the ones worth testing for are manganese, arsenic and nitrate, plus bacteria every year.

Compare lab tests Find my county

About 816,000 people in Oregon get their water from a private well, about 2 in 10 residents.

Three ways to get tested, cheapest first.

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A lab Oregon certifies

The state's list of labs certified for drinking water. Many sell bottles you pick up or get by mail, and their results count for a home sale or loan.

Labs certified by Oregon
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A mail-in kit

Order online, fill the bottles at your kitchen tap and get results by email in about a week. Full well tests run about $210 to $220.

Compare kits for Oregon
Buying a house or drilling a new well in Oregon?

Under the Domestic Well Testing Act, sellers must test the well for arsenic, nitrate and total coliform bacteria during a real estate transaction and send the results to the buyer and OHA within 90 days.

Look up a well's drilling report

What turns up in Oregon wells.

Share of tested wells over the limit, from lab tests the USGS, EPA and state agencies collected since 2000. Your own well needs its own test.

Tested wells over the limit, statewide
Manganese19%337 of 1,741Arsenic13%227 of 1,767Nitrate11%341 of 3,072Radon4%1 of 23Lead2%34 of 1,488Uranium2%20 of 1,281Fluoride1%4 of 405
GermsTest every year, whatever the chart says
Coliform bacteria27%268 of 993
StainsNot a health risk
Iron stains38%689 of 1,829

Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+

Lab results: Water Quality Portal (USGS and EPA)

Where it shows up most

  • Nitrate shows up most in Morrow County (about 5 in 10 wells), Umatilla County (about 1 in 4 wells), Lane County (about 2 in 10 wells).
  • Arsenic shows up most in Washington County (about 1 in 3 wells), Harney County (about 3 in 10 wells), Benton County (about 2 in 10 wells).
  • Uranium shows up most in Morrow County (about 1 in 11 wells), Multnomah County (about 1 in 19 wells).

Find your county.

8 counties have a full report with local test results and well depths.

ClackamasDeschutesJacksonJosephineLaneLinnMarionWashington
Every county in Oregon: people on wells and typical depth
CountyPeople on private wellsShare of residentsTypical well depth
Clackamas County97,08723%218 ft
Marion County85,56225%133 ft
Lane County77,04420%120 ft
Jackson County61,86328%180 ft
Washington County54,2699%190 ft
Josephine County52,39659%126 ft
Linn County51,43640%100 ft
Deschutes County37,54719%120 ft
Douglas County33,53830%140 ft
Yamhill County23,54622%175 ft
Benton County23,13524%160 ft
Umatilla County22,34428%185 ft
Klamath County21,60631%160 ft
Columbia County19,06036%200 ft
Coos County19,00329%112 ft
Polk County16,31219%145 ft
Multnomah County15,3342%200 ft
Crook County13,74956%390 ft
Malheur County13,66243%85 ft
Lincoln County8,74217%110 ft
Curry County7,90734%104 ft
Union County7,58429%160 ft
Jefferson County6,68627%330 ft
Wasco County6,28224%309 ft
Tillamook County5,90422%116 ft
Baker County5,42633%180 ft
Clatsop County5,38413%80 ft
Morrow County4,31735%145 ft
Lake County3,99349%130 ft
Hood River County3,38814%190 ft
Wallowa County3,34945%139 ft
Harney County3,18843%123 ft
Grant County3,01442%165 ft
Wheeler County80956%160 ft
Sherman County76241%266 ft
Gilliam County62531%330 ft

Questions people ask about well water in Oregon

Does Oregon require private wells to be tested?

Under the Domestic Well Testing Act, sellers must test the well for arsenic, nitrate and total coliform bacteria during a real estate transaction and send the results to the buyer and OHA within 90 days.

Where can I get my well water tested in Oregon?

Otherwise, use a lab certified by Oregon for drinking water. The state's list is linked on this page.

Where these numbers come from

  • How many people use wells: EPA estimates from the 2020 Census.
  • Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000.
  • State programs and links: Oregon Health Authority.