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Well Testing & Regulations

Domestic Well Testing Act and Real Estate Transaction (RET) form instructions

  Domestic Well Testing Act 

  • The Domestic Well Testing Act (ORS 448.271) applies to the sale or exchange of real estate with a domestic well. A domestic well is used for purposes like drinking, cooking, washing, or bathing. During the real estate transaction (RET), the seller must test the well's water quality and share the results and the RET form to comply with the Domestic Well Testing Act. Properties with spring wells, irrigation only wells, or well located on undeveloped land are exempt from these rules. 

  • Oregon Administrative Rules 333-061-0305 to 333-061-0335 further define the actions you must take if you are selling your home or property. 

  • If you are building a new well, other regulations apply.

Testing requirements

  • The seller or their chosen representative must test for arsenic (arsénico), nitrate (nitrato), and total coliform bacteria (bacterias coliformes)
  • Samples may be collected by water professionals or anyone able to follow the instructions for taking a water sample described below.
  • Samples must be tested by an accredited laboratory
  • Test results are valid for one year. The seller can use the same test results on multiple offers if the transactions occur during the 1-year time frame. 

Collecting a water sample

To test your water, you must take a water sample.

  • Use the water collection kit supplied by the laboratory. Most will provide detailed instructions. If they don't, refer to the guidance below on collecting a water sample.
  • Get the sample to the lab as soon as possible, within 24 hours of collection.
  • The sample must be taken correctly in order to show the most accurate results.
  • Test results are usually ready one to three business days after the lab receives the samples. Some tests (like arsenic) may take up to 10 business days or longer dependent on analysis type.
Collecting a Water Sample  Find an Accredited Laboratory

Complete the RET form

The RET form can be completed online or by hand using the printable version. 


You can find well information including well tag ID, well ID number, well depth, township, range, and section on the Water Resource Department's Well Report Query tool.

Submit the RET form and test results 

  • The seller or their chosen representative has 90 days to send a copy of the test results to the potential buyer.
  • The seller or their chosen representative has 90 days to send the RET form and a copy of the test results (arsenic, nitrate, and total coliform bacteria) to the Oregon Health Authority. 
  • You can send RET forms and test results through any one of these methods: