Free Testing for Wells Impacted by Flood Waters
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If floodwater reached your well, assume your well is contaminated. Water from your well should not be used for drinking, cooking or brushing your teeth until the floodwater recedes. Also:

  • Avoid electrical shock. Do not approach a flooded well until it has been completely disconnected from its power source.
  • If floodwater covered your well or may have entered your well directly, have a licensed well contractor inspect the well, clean out sediment or debris and disinfect it with a chlorine solution. Using your well pump to remove sediment or debris could ruin the pump. To find a licensed well contractor check the Licensed Well and Boring Contractor Directory.
  • If floodwater reached your well, have a licensed well contractor disinfect your well – or complete the disinfection yourself – even if you don’t think the floodwater entered the well. Detailed instructions are available at Disinfecting Flooded Private Water Wells.
  • After you or the licensed well contractor disinfects your well and pumps out the chlorine solution, contact your county health department or a laboratory accredited by MDH about how to get your well water tested for coliform bacteria. They will provide instructions on how to submit a water sample for testing. Accredited Labs in Minnesota Accepting Samples from Private Well Owners (PDF).    
    • If your well water test comes back positive for coliform bacteria, repeat the disinfection and testing process. You may need to disinfect and test your well several times before your well is free of bacterial contamination.
    • Do not use the water from your well until the lab has informed you that it is safe and free of bacterial contamination.

If floodwater came within 50 feet of your well – but did not reach the well – MDH recommends that you have your well water tested for coliform bacteria as a precaution. You do not need to disinfect your well before having it tested. If the test comes back positive for bacteria, however, the well needs to be disinfected.

If your well was impacted by flood water, Dodge County has free bacteria test kits. Test kits can be picked up from Environmental Services (Mantorville) or Public Health (Dodge Center), while supplies last.

For more information, please contact the Well Management Section at MDH at or 651-201-4600 or 800-383-9808 or visit the Natural Disasters and Private Wells page on the MDH website.