Assessing Private Well Safety After Flooding

June 19, 2008

By Tom Glanville, Department of Agricultural and Biosystems Engineering

As the floodwater recede, we are getting lots of questions from rural residents wanting to know if their wells are safe to use. Here are three of the most common questions.

There was no flood water on my property, but the nearby fields and road were flooded. How do I know if my well should be tested. 

Any well that has been submerged beneath flood waters or high groundwater tables (for well heads located below ground in well pits) definitely needs to be tested, but even if the well has not been submerged, the current saturated soil profile increases the risks of pollutant transport and so now would be a good idea for all rural well owners to consider having their well water tested for coliform bacteria and nitrate.

Both the Iowa City and Ankeny branches of the University Hygienic Lab (UHL) are operational and are offering free water test kits to residents of counties that are included in the Governor Culver's disaster declaration. These kits are available through local county health departments. The best point of contact would be your county sanitarian.

Hog confinements couldn’t spread manure because the cropland was so wet. Now a confinement operation near my farm has been, do I need to have my well checked?

The risks of private well contamination always go up during wet weather, regardless of whether a well is located near to a livestock operation or not. This is due mainly to the fact that many of the private wells used in rural Iowa are old, shallow and leaky.

Even during “normal” years about 30 percent of private water well samples submitted voluntarily to the University Hygenic Laboratory (UHL) by well owners are found to contain unsafe levels of coliform bacteria and/or nitrate. 

Are there any other places besides the University Hygenic Lab that can test my well water?

Several commercial labs throughout the state also offer water quality testing. To make sure, however, that a commercial lab is properly qualified and equipped to perform accurate drinking water testing, clients should inquire whether the lab is state-certified to test water for Iowa public water supplies. Personnel and equipment at state-certified commercial labs are periodically tested and reviewed by the Iowa Department of Natural Resources and UHL to insure that their work is accurate and done according to approved procedures.


Tom Glanville is a professor of agricultural and biosystems engineering with research and extension responsibilities

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