Private well guide

Well Water in Oregon: Testing, Rules, Labs and Licensed Contractors

252,612 households in Oregon get their water from a private well. Here is what the state requires, where to get it tested, and who is licensed to work on it.

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162Licensed contractorschecked against state records
20Certified labsfrom the state certified list
36Counties covered
252,612Households on wells16% of households (est.)

About 250,000 Oregon households, one in six, drink from a private well, and outside the Willamette Valley’s cities and the coast it is a third to half of homes. Oregon keeps one of the best well log archives in the country, tests every domestic well when a house is sold, and has more naturally occurring arsenic and farm-country nitrate in its groundwater than most owners realize.

Who is in charge of an Oregon well

The Water Resources Department licenses and bonds water supply well constructors, writes the construction standards in OAR 690-210, collects a start card and fee before every well is drilled and a well report within 30 days after, and publishes every report since the 1950s in its online well log query, searchable by township, county or owner. A landowner may drill a well on their own land with a Landowner’s Water Well Permit under the same standards. Water quality belongs to the Oregon Health Authority’s Domestic Well Safety Program, which runs the Domestic Well Testing Act, accredits the labs through ORELAP and keeps the statewide database of real estate transaction results.

What is required, and what is left to you

A licensed constructor, the start card, construction to the standard and the well report. Oregon does not test a new well’s water, but it does test at sale: the seller must have an accredited lab test for arsenic, nitrate and total coliform and report the results to OHA within 90 days. Between sales the water is yours to watch. OHA’s advice is bacteria and nitrate every year and arsenic every three to five years, and in the groundwater management areas nitrate every year without fail.

At a glance

Water test for a new wellNot required statewide

No statewide water test on a new well. The well must be built by an OWRD-licensed, bonded water supply well constructor (or by the landowner under a Landowner's Water Well Permit) to the OAR 690-210 standards, with a start card filed and the fee paid before drilling, a metal well ID tag attached, and a well report filed with OWRD within 30 days. Setbacks are 50 ft from a septic tank and 100 ft from a drainfield. Some counties ask for a bacteria test before a building permit is finaled, and lenders usually do.

Water test when a home is soldRequired

Yes. Oregon's Domestic Well Testing Act (ORS 448.271, OAR 333-061-0305 to 0335) requires the seller of a property with a domestic well to have the water tested by an ORELAP-accredited lab for arsenic, nitrate and total coliform bacteria, give the results to the buyer and report them to the Oregon Health Authority within 90 days of the sale. It is one of only a handful of state laws in the country that test private wells at transfer.

What the state recommends

The Oregon Health Authority recommends testing a domestic well every year for coliform bacteria and nitrate, and every three to five years for arsenic (found across the Willamette Valley, the Tualatin basin, Lane County and Klamath and Lake counties), plus pH, hardness, iron, manganese, lead and copper once. Add uranium and radon in Lane County and the Cascade foothills, and test again after flooding, well work or a change in taste, color or smell. In the Southern Willamette Valley and Lower Umatilla Basin Groundwater Management Areas, nitrate is the test that matters most.

Free or low-cost testingAvailable

No statewide free program. The OSU Extension Well Water Program runs free nitrate screening clinics around the state and publishes testing guidance, and Oregon Health Authority's Domestic Well Safety Program (971-673-0440) helps owners read results. The Lower Umatilla Basin (Morrow and Umatilla counties) has state-funded free nitrate testing and water delivery for affected wells. Otherwise the ORELAP labs below charge $30 to $60 for bacteria and nitrate and $150 to $250 for the real estate panel.

What the water is like

The Willamette Valley’s alluvium and basalt give plentiful water at 100 to 300 feet, but the same sediments carry naturally occurring arsenic in a broad band from the Tualatin basin through Lane County, and the sandy soils of the southern valley have leached farm nitrate into the shallow aquifer for decades, which is why the state drew a Groundwater Management Area there. Central Oregon’s high desert sits on young lava: wells around Bend, Redmond and Madras go 300 to 700 feet to reach the water table, and the water is good but expensive to reach. The Rogue Valley and the Klamath and Lake basins drill volcanic rock with arsenic and, in places, boron. North-central and eastern Oregon draw from the Columbia River basalts, deep and slowly declining, with nitrate from irrigated farming in the Lower Umatilla Basin bad enough that the state delivers water to affected homes. The coast has shallow sand wells with iron and bacteria. Lane County and the Cascade foothills add uranium and radon from granitic rock.

ORELAP-accredited labs

Oregon’s accreditation program, ORELAP, flags which drinking water labs accept samples from the public, and that list is what appears below: about 20 Oregon labs from Portland and Salem to Medford, Bend, Klamath Falls and Pendleton, most of which sell the real estate transaction panel and mail bottles anywhere in the state. Each profile shows which of the homeowner tests the lab is accredited for, checked one analyte at a time against the ORELAP search on September 30, 2026.

20 certified labs

See all 20 certified labs in Oregon

OWRD-licensed well constructors

Oregon licenses the individual constructor and requires a bond, and it licenses drillers only: there is no separate pump installer license, so the constructor who builds the well usually sets the pump too. Every profile below is built from OWRD’s license download of water supply constructors, grouped under the business each works for, with license numbers shown and helpers and trainees counted. Where OWRD’s well report archive has reports under the license or the bonded company name, the profile shows how many wells the business has filed since 2016, the counties it drills in and the typical depth of its new wells.

162 licensed contractors

See all 162 licensed contractors in Oregon

By county

Well use runs from under 1% of homes in Clatsop County and 4% in Multnomah to 44% in Crook, Polk and Wheeler, 54% in Josephine and 57% in Lake. Each county page carries its well population, the typical depth of new domestic wells reported to OWRD since 2000, the nearest accredited labs and the licensed constructors based there.

Oregon well water questions

Do I need a permit to drill a well in Oregon?

Not a permit as such, but your constructor must file a start card with OWRD and pay the fee before drilling, attach a well ID tag, and file the well report within 30 days. A landowner drilling their own well needs a Landowner’s Water Well Permit first. Counties may require a building or land use approval on top.

Is a water test required when I sell my house?

Yes. Under the Domestic Well Testing Act the seller must have an ORELAP-accredited lab test the well for arsenic, nitrate and total coliform, give the results to the buyer and report them to the Oregon Health Authority within 90 days of closing.

How do I find the record for my well?

Search OWRD’s well log query by county and township, by owner name or by the well ID tag number. Reports go back decades and show the constructor, depth, casing, seal, yield and static water level.

Which lab should I use?

Any lab on the ORELAP list below that accepts public samples. For the yearly bacteria and nitrate check any of them will do; for arsenic, uranium, VOCs or PFAS pick a lab accredited for that test.

My real estate test found arsenic. What now?

Arsenic above 10 parts per billion is common in the Willamette Valley and central Oregon and is treatable with a point-of-use reverse osmosis unit or a whole-house adsorption system. Retest after installation and every year after, and tell OHA’s Domestic Well Safety Program, which can walk you through the options.