After the Flood - Private Drinking Wells
Floodwater from recent heavy rains, snow melt, and flooding may potentially carry pollutants with it. During floods, water comes into contact with things it normally wouldn’t, such as gasoline, animal waste, chemical storage facilities and more. If your private drinking water well has been impacted by flood water, your water supply may have been contaminated with pollutants carried in the flood water.
Do not use the water for cooking, drinking, or brushing teeth until laboratory analysis confirms it is safe. (See water treatment options, including shock chlorination.)
- Wells at greatest risk of contamination from flood water or surface water runoff include:
- Wells located in well pits.
- Dug wells or any wells that do not have a watertight casing.
- Wells that do not have watertight caps.
- Wells that lack a grout seal in the annular space.
- Wells that were submerged with flood water or surface water runoff.
Managing Wells After Flooding
If you think your private drinking water well was impacted by flood water:
- Do not use the water for cooking, drinking, or brushing teeth until laboratory analysis confirms it is safe.
- Contact a licensed well contractor. The contractor should:
- Inspect the well.
- Clean out any debris or sediment that entered the well.
- Disinfect the well with shock chlorination. The system must be flushed (three to four hours) after the disinfectant has been retained undisturbed in the system for six to eight hours to remove any debris and flush contaminates from the water system before testing for drinkability.
- Then, contact a certified testing laboratory and tell them you want to have your private water supply tested for bacteria. They will provide a test kit with detailed instructions. (See list of certified laboratories.)
- Don't use the water from your well until the laboratory has informed you that it is safe and free of bacterial contamination. It may be necessary to repeat the disinfection and testing process several times before the well is free of contamination.
If flood water came close to your well (100 feet or less) but did not reach the well, have your water tested as a precaution.
For more information on testing and treating water from a well that may have been contaminated by flood water, see these UNL Extension NebGuides:
- Drinking Water Treatment
- Emergency Disinfection of Drinking Water
- Drinking Water: Testing for Quality
- Drinking Water: Bacteria
- Drinking Water Treatment: Shock Chlorination
More information at flood.unl.edu