Flooding: Drinking Water Issues

Municipal Water Users

  • Turn on and run faucets for at least five minutes before using water for drinking or food preparation.
  • If a "boil water" notice is issued, follow any directions given by the Wisconsin Department of Natural Resources, local water utility, or local health department.

Private Well Owners

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 for several weeks while you fix your well.

Follow these steps after your well is flooded.
  1. Use safe water for drinking, food preparation, and personal hygiene.
    Use safe water for drinking, preparing food, brushing teeth, bathing, showering, and washing hands 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. Safe water includes bottled water, tap water that you boiled for one minute, or water from a well that was not flooded.
  2. Wait until the well is no longer in contact with water. This could take days to week.
  3. Disinfect the well.
    We recommend that you have your well disinfected by a licensed well driller or pump installer. If you are unable to hire a professional, you can disinfect your own well using the steps in this DNR publication (page 4). Pay close attention to all steps as this work may pose chemical or electrical hazards.
  4. Wait for disinfection to work. This will take a week.
  5. Test for coliform and E. coli bacteria.
    You can get a free flood test kit from your local health department. Be sure to use the proper sampling procedure to avoid accidental contamination.
  6. Wait for the test results. This could take days to weeks.
  7. 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. However, if bacteria are present, the water is not yet safe to use.
Follow these steps if bacteria is present in your well.

If your test results show that you have bacteria in your well, you should follow these additional steps to make sure the water is safe before using it for drinking, cooking, and personal hygiene.

  1. Continue to use safe water.
    If total coliform are present AND E. coli are present: Do not use the water for drinking, preparing food, brushing teeth, bathing, showering, and washing hands.
    If total coliform are present, but E. coli are absent: Do not use the water for drinking, preparing food, and brushing teeth. You can use the water for bathing, showering, and washing hands.
  2. 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.
  3. Wait for the test results. This could take days to weeks.
  4. 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.
Last Revised: March 4, 2019