Selling a home with a well? Oregon requires a water test.

The Domestic Well Testing Act (ORS 448.271) sets out who tests, what gets tested and who gets the results. Here it is in plain words.

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The three required tests

Total coliform bacteria

Shows whether bacteria are getting into the water.

Nitrate

A nitrogen compound that can reach groundwater.

Arsenic

An element that can be in groundwater.

The Oregon Health Authority (OHA) can require more tests in certain areas of public health concern.

How it works

Offer acceptedThe seller’s duty to test starts here.

Sample collectedUsing the lab’s bottles and instructions.

To the lab in 24 hoursAn accredited lab only. Home kits don’t count.

ResultsUsually 1–3 business days, arsenic can take 10 or more.

Report in 90 daysTo the buyer, and to OHA with the RET form.

Who does what

The seller

Has the well tested after accepting an offer, then gives the buyer a copy of the results and sends OHA the results with its Real Estate Transaction (RET) form, both within 90 days. A seller can have someone else handle it.

The buyer

Gets a copy of the results. The test can’t be skipped: OHA’s rules say it is required even if the buyer agrees not to test.

Your lender may have its own requirements. Some loans come with water or well conditions beyond what the state requires. Ask your lender early what they need, so it can be done on the same visit.

Good to know

Results are good for one year under OHA’s rules, and can be used for more than one offer in that year.

Not covered: springs, irrigation-only wells and wells on undeveloped land.

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The RET form asks for the well tag ID, well ID number, depth and location. These are in the state’s Well Report Query.

Most results never reach the state. In 2017 testimony to the Legislature, OHA said fewer than 1 in 4 home-sale well test results done by labs show up in its data. We can file the RET form for the seller (optional, added fee). Source

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Test early. If something comes back high, there’s time to treat it before closing.

What if the results show a problem?

The results still go to the buyer and to OHA. Many problems can be fixed with water treatment, and the buyer and seller can work out the rest in the sale. We can treat the water and retest after.

Who can collect the sample?

OHA says a water professional or anyone who can follow the lab’s sampling instructions. The sample has to reach the lab within 24 hours.

Not selling?

Testing isn’t required, but it’s still recommended. See how often to test your well.

We handle the whole thing

We collect the sample, get it to an Oregon-accredited (ORELAP) lab in time, file the RET form with OHA for the seller (optional, added fee), and can do the flow test on the same visit.

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Sources: ORS 448.271 · Oregon Health Authority: Domestic Well Testing & Real Estate Transactions · OAR 333-061-0325. General information, not legal advice. Last checked November 2026; laws change, so check OHA’s page for the latest.