Testing for Drinking Water Safety

Well Water Program

If you have a well, two inexpensive tests can serve as indicators of the overall condition of your water.

What to test

It is not practical for homeowners to test for all possible contaminants.

If you have a well, two inexpensive tests can serve as indicators of the overall condition of your water. If you live in an area that is noted for other issues please think about including those tests.

Coliform Bacteria

Coliform bacteria don't usually cause illness, but they serve as an indicator that disease=causing organisms CAN Get into your well.


Nitrate leaches very easily through the soil to groundwater from farms, gardens, septic systems, animal yards, and manure piles. Nitrate is an indicator that other surface contaminants have the potential to leach into your drinking water.


When Should I Test?

Test for coliform bacteria

  • At least once a year;
  • Whenever you notice a change in taste or color of the water;
  • After work on the well;
  • If you notice the cap is not secure;
  • If you notice surface water standing around the base of the well;
  • When you purchase a new home with a well (required by Oregon law).


Test for nitrate

  • If you expect to have a pregnant woman or newborn baby drink the water;
  • Once a year if you live near:
    • Fertilized fields
    • Rural development with septic systems
    • Pastures or pens with animals/livestock
    • A perfect law;
  • If you have had a nitrate level in the past - then test once a year, and keep records.

Remember that nitrate levels vary depending on the time of year and the weather conditions. If you want to test your water for nitrate free screenings are available at Well Water sponsored events.


Where is Well Water Tested?

  • There are Certified Drinking Water Laboratories for the State of Oregon.
    List of Certified Labs. Procedures and prices vary.
  • Real Estate offices may know, because testing is required for rural home sales.
  • The OSU Well Water Program offers free Nitrate Screenings at our events. If you would like to have us come to your community, please contact us directly.


What Else Should I Test For?

  • If you have an aesthetic concern with your water, such as taste, smell, or staining, ask the lab which test you need.
  • If you suspect a chemical spill, such as pesticide or petroleum, occurred anytime in the past, you may want to set up a long-term testing program to monitor for the suspected contaminant. Contact us for assistance.


Where can I get more information?

Read Keeping Your Well Water Well (OSU Extension Service) or contact us with your questions.