Central Iowa struggles with high nitrates

Water restrictions in central Iowa have been eased, but high levels of nitrates continue to be of concern to operators of the state’s largest water plant.

The Central Iowa Water Works has banned lawn watering for the last two weeks.

At a tour of one of their treatment facilities Friday, leadership reiterated this is a water quality issue and not a quantity issue. Recent rainfall has added to river levels, but not done much to significantly dilute the makeup of the water. 

CIWW pulls from both the Raccoon and Des Moines Rivers. All of the coalitions nitrate removal plants have been running for the last 60 days. According to utility officials, these are the highest nitrate levels seen following a drought. 

Ted Corrigan, CEO, Des Moines Water Works: "We had some pretty dry times from 2020 to 2023. significant drought for four years in a row. We saw some higher nitrate concentrations last year, but then we had enough rain to kind of dilute this year. We're having sort of more normal, spring precipitation. And we think although there are many factors, those are some important ones that are, leading to, near record high concentrations in our rivers."