Is Your Private Well Water Safe to Drink After a Flood?

By: Amy Timmerman – Extension Educator

As the flood waters recede and we are able to get back in to our farms and ranches it is important to think about drinking water safety.  It is common for private wells to be immersed with the flood waters.  The flood waters commonly contain high levels of bacteria such as fecal coliforms and E. coli.  These microbes can cause short-term health effects such as diarrhea, cramps, nausea, headaches or other symptoms.  Infants and young children, some of the elderly and people with severely compromised immune systems may be more susceptible.

Until your well water has tested negative for bacteria, it is recommend to boil your water at a vigorous boil for one minute prior to use.  For more information on boiling water and/or chlorinating personal water please refer to


How to test for bacteria contamination

  • A sterile bottle must be used to place the water sample in to assure an accurate report.  Sterile bottles can be obtained at the following locations.
    • Nebraska Extension in Greeley County – Greeley (M,F)
    • Nebraska Extension in Howard County – St. Paul Courthouse (M,W,F)
    • Nebraska Extension in Sherman County – Loup City Courthouse (M-F)
    • Nebraska Extension in Valley County – Ord Fairgrounds (M-F)

    The bottle may contain a small white pill or powder.  If it does, leave the pill or powder in the bottle. Choose an inside faucet to collect the water sample and remove the aerator if one is present.  Turn the water on cold water and allow it to run for about 5 minutes.  This assure that fresh clean water from the well is being collected.Avoid touching or contaminating the inside of the bottle or cap.  Carefully remove the lid from the sample containers and hold the cap by the outside of the cap. (If you touch the inside of the cap or battle, you could contaminate the sample with bacteria). Fill the container with water to the marked line if a line is present.  If no line is present fill the bottle ¾’s full.

      Samples must reach the laboratory within 30 hours.  Until you can ship the sample, keep the sample cool either in a refrigerator or coolers.  Do not mail samples on Thursday, Friday or Saturday as they may be delayed in reaching the laboratory.


      There a number of different tests available for different contaminations.  The minimum recommended to test is for bacteria and nitrates.  Please remember that there may be other contaminates present that would make the water safe or desirable for domestic use.  Some commercial labs offer multi-parameter packages that include tests for the most common contaminants of concern.

      Testing facilities

       rtified Water Testing Laboratories in Nebraska

      • American Agricultural Laboratory – 700 East D Street, McCook, NE 69001 (308-345-3670)
      • Central District Health Department – 1137 South Locust Street, Grand Island NE 68801 (308-385-5157)
      • Enviro Services Inc. – 818 S. Beltline Hwy East, Scottsbluff, NE 69361 (308-632-3933)
      • Midwest Laboratories, Inc. – 13611 B St., Omaha, NE 68144 (402-334-7770)


      What to do after receiving test results

      If your test reports come back negative for bacteria, you can go back to normal water usage for the home without boiling or treating the water.

      If tests reports are positive for bacteria, it is recommended to shock your private well with chlorine.  For full instructions refer to the NebGuide “Drinking Water Treatment: Shock Chlorination” found at   This publication will help determine the amount of bleach that will need to be poured into the well depending on well diameter, volume of water, total depth of water, etc.