If flood water came near your private drinking water well, your water supply may have been contaminated with pollutants carried in the flood water. In addition, wells can be contaminated by surface water runoff even if the surrounding area is not flooded, said Sharon O. Skipton, Extension water quality educator at the University of Nebraska-Lincoln
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.
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 (3-4 hours) after the disinfectant has been retained undisturbed in the system 6-8 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.
Don't use the water from your well until the laboratory has informed you that it is safe, and free of bacterial contamination.