Oregon requires the seller to test a domestic well for arsenic, nitrates and total coliform bacteria after accepting an offer. Here is how it works.
If the home you are selling has a well that supplies water for domestic use, Oregon law requires a water test as part of the sale. The seller's duty starts upon accepting an offer, and the results go to both the buyer and the Oregon Health Authority.
The standard Oregon sale agreement adds a Private Well Addendum (OREF 082) that sets the timing, lets the buyer ask for more tests, and gives both sides a window to negotiate if the results show problems. For the rest of the inspection process, see our home inspection checklist for Oregon buyers, and if you are getting ready to list, our pre-listing checklist.
Questions
Does the seller have to test the well water in Oregon?
Yes. In Oregon, when a home with a well that supplies water for domestic use is sold or exchanged, the seller must, upon accepting an offer, have the well tested for arsenic, nitrates and total coliform bacteria, and must send the results to the Oregon Health Authority and to the buyer within 90 days of receiving them.
Where do the well samples go, and how long are the results good for?
The Oregon Health Authority says the samples must go to an accredited lab, and the results are valid for one year.
Which wells are exempt from the sale testing rule?
The Oregon Health Authority says properties with spring wells, irrigation-only wells, or wells on undeveloped land are exempt.
Can the buyer waive the required well tests?
No. Oregon's rule says the required lab tests cannot be waived, even if the buyer agrees not to have the well tested.
What does the Private Well Addendum do?
The standard Oregon sale agreement (OREF 001) has the buyer attach the Private Well Addendum (OREF 082). It makes the seller order the required tests at the seller's cost within the number of business days written in the addendum (five if left blank), send the results to the buyer and the Health Authority promptly when they arrive, and file the state's data sheet.
Can the buyer ask for more well tests?
Yes. The required tests are minimums. In the same addendum the buyer can choose more tests, such as well flow, extra arsenic, nitrate and bacteria tests, lead, or other water quality tests, and for each one the parties check whether the buyer or the seller pays.
What happens if the well tests show problems?
If the reports show substantial problems, the buyer sends the seller a list, and the two sides get a short window to negotiate. If they cannot agree, the buyer can back out with a refund of deposits. Ask your broker what to request, and talk with a well professional or the lab about what the results mean.
Have a question about your own sale? Talk with a Ryan Realty broker, and we will walk you through it.
Sources
- ORS 448.271, testing of domestic well at sale: Oregon Revised Statutes, chapter 448
- Oregon Health Authority, Domestic Well Safety, Testing Regulations
- OAR 333-061-0325, domestic well testing in real estate transactions: Oregon Administrative Rules
- OAR 333-061-0310 and OAR 333-061-0324
- OREF 001 Residential Real Estate Sale Agreement (Released 01/2026), Section 13 and Section 12.2
- OREF 082 Private Well Addendum (Released 01/2026), Sections 1 to 7
Matt RyanOwner & Principal Broker at Ryan Realty.
