Flooding: Private Wells

When your well has been flooded, bacteria and other harmful organisms can get into your water.

It will take time for the water to be safe to use again. You will need a safe source of water to use for several weeks while you fix your well. Safe water includes bottled water, tap water that you boiled for one minute, or water from a well that was not flooded.

Follow these steps after your well is flooded:

Flowchart showing what to do when your well is flooded

Click the image for a printable version of this information.

  1. Use safe water for drinking, food preparation, and personal hygiene until your well water is tested and found to be free of bacteria. Do not use water or ice from your refrigerator or other appliances.
  2. Disinfect the well. Have your well disinfected by a licensed well driller or pump installer.
  3. Test for coliform and E. coli bacteria. You may be able to get a free flood test kit from your local health department. Be sure to use the proper sampling procedure to avoid accidental contamination.
  4. Learn if the water is safe to use. If the test results show that bacteria are absent, the water is safe to use for drinking, preparing food, and personal hygiene.
  5. If bacteria are present, continue to use safe water.
  6. Have a confirmation sample tested for bacteria. Collect another water sample and have it analyzed to confirm the results. Be sure to use the proper sampling procedure.
  7. Take further actions if bacteria are still present. You should have your well inspected by a licensed well driller or pump installer. You may need to disinfect again or make repairs to your well or plumbing.


The Department of Natural Resources (DNR) has more information on how to address a flooded well.

The DNR has additional information on coping with the effects of flooding.

List of local health departments.

List of regional private well specialists.

Information on other common drinking well concerns.

    Last Revised: October 6, 2020