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University of Iowa News Release

Release: April 30, 2003

Test Your Well This Spring, Say Water Quality Experts

As part of National Drinking Water Week, May 4-10, water quality experts at the University Hygienic Laboratory (UHL) encourage Iowans who have their own wells to test their water this spring.

A yearly routine inspection of the well includes checking to see that the wellhead is clean, the well cap is tight and no structural defects exist that could allow surface water to enter the system. Assistance may be available from county health departments, extension services and certified well drillers.

Testing the water quality for total coliform bacteria and nitrates also is important, said Nancy Hall, a public health microbiologist at the UHL.

"This is a good time to test your well water, because spring rains cause a lot of surface and groundwater movement which can carry contaminants into your well," Hall said.

Total coliform bacteria are a group of naturally occurring bacteria that are present in all surface water and groundwater affected by surface water. As surface water moves through the soil, a natural filtration process removes coliform bacteria. The presence of coliform bacteria in a drinking water supply indicates that a pathway exists allowing surface water to enter the well water supply.

Nitrates come from nitrogen, a naturally occurring element in the environment and essential to living matter. Nitrogen also can enter the soil from other sources such as septic systems, animal feedlots, manure storage facilities or nitrogen fertilizers. Nitrate contamination is more likely to occur in shallow wells and wells that are poorly located, constructed or maintained.

Drinking water with high levels of nitrates can be a health risk, especially to infants under 6-months-old. Whether nitrates cause cancer and other adverse health effects in adults is unclear. A lot of research currently is being conducted in this area, but "the jury is still out," Hall said.

Contact the University Hygienic Laboratory at (319) 335-4500 or visit the UHL online at to learn more about drinking water quality or to purchase a water sampling kit.

Many counties in Iowa also participate in the state's "Grants to Counties" program, which provides free testing to Iowa residents whose primary source of drinking water comes from private wells. Residents with private wells can contact their county health department and receive a free bacteria/nitrate test of their well water. If there is a problem with a well, or if additional testing is needed, the county environmental health specialist (sanitarian) will contact the UHL to arrange additional, extensive tests at no charge to the well owner. Contact your county health department for more information.

STORY SOURCE: University of Iowa Health Science Relations, 5135 Westlawn, Iowa City, Iowa 52242-1178

CONTACT(S): David Pedersen, (319) 335-8032,