IOWA CITY — The state program for testing private drinking water wells suffers from “severe under-utilization,” according to a University of Iowa study.

The “Grants To Counties” program funds testing for nitrate, bacteria and arsenic, as well as plugging old wells. In recent years, counties left as much as 55% of the total funding untouched. The U-I’s Silvia Secchi co-authored the report.

“We would really like for all that money to be spent because we know that we’re not testing as much as we should,” Secchi says. “The rule of thumb is that you should test once a year every well and we’re not doing that.” The state recommends Iowans test their private wells annually for contaminants that are linked to cancer and other health issues.

Secchi says not testing these wells is concerning because they’re largely unregulated, unlike larger systems. “These people are really the most vulnerable population when it comes to drinking water in the state,” Secchi says, “because there is nobody but themselves who is responsible for the testing.”

It’s estimated 10% of Iowans, or around 300,000 people, rely on private wells for their drinking water.