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Testing Recommendations

Routine Domestic Well Testing

This page contains information on:

People in Oregon are only required to test their well water when selling a property with a well. Visit the Real Estate Transaction Page for more information on testing and reporting. 

If you are building a new well, other regulations apply

Test well water regularly to protect your health!

Test your well
water for:* 
CostSymptoms of exposure include: 
Coliform and
E.coli bacteria
Every year$20 to $40Diarrhea, cramps, nausea, headaches or other symptoms
NitrateEvery year$20 to $40Babies are at the highest risk. Decreased oxygen in tissues, decrease in blood pressure, increased heart rate, headaches, stomach cramps, vomiting, and sometimes death.
ArsenicEvery three to five years$25 to $45Problems of skin, circulatory system nervous system, lungs, and bladder. These health problems include some forms of cancer. 

  * You may wish to test for other contaminants
** You may need to test more frequently if: 
  • The well has a history of contamination
  • Your septic system has recently malfunctioned
  • Household members have a stomach illness
  • Infants are drinking the water
  • Any equipment has broken or malfunctioned

How to test well water

Take a water sample and send it to an accredited laboratory

  • If the water test is for a real estate transaction, samples must be collected according to the Oregon Administrative Rule OAR 333-061-0335 and analyzed by an accredited laboratory per OAR 333-061-0330
  • Use the water collection kit supplied by the laboratory. Most will provide detailed instructions. If they don't, refer to the DWSP collecting a water sample guidance.
  • 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.

What to do with test results


If the well water does not meet safety standards, visit our Treatment and Maintenance page and Well User Resources page.

If bacteria or nitrate are present

This most likely means that surface contamination has found its way into the well and disease-causing organisms may be in your water. You may need to adjust the environment around your wellhead. You may also need to inspect your well system for damage or malfunctions. You may also install a treatment system.

If arsenic is present

If initial test results are above 8ppb, you should retest. If high concentrations continue; a treatment system should be installed.

Continue regular testing with a treatment system. Testing should be done:

  • Every year at the faucet that you drink out of and
  • Every three years at the wellhead.


If the well water does not meet safety standards, more resources are available.


  • If you are routinely testing your well, you do not need to report your results.

If you are selling your property, you will need to report test results to the Domestic Well Safety Program. Visit the real estate transaction page for more information on testing and reporting.