Water Works for years has tried to force or cajole farmers upstream to reduce the runoff of fertilizer that leaves the rivers with sky-high nitrate levels, but lawsuits and legislative lobbying have failed. Now, it's considering a drastic measure that, as a rule, large cities just don't do — drilling wells to find clean water.
Small communities and individuals use wells, but large U.S. metro areas have always relied primarily on rivers and lakes for the large volumes of water needed. Surface sources provide about 70 percent of fresh water in the U.S., as a reliance on wells for big populations would otherwise quickly deplete aquifers.
However, the utility in Des Moines is planning to spend up to $30 million to drill wells to mix in pure water when the rivers have especially high nitrate levels from farm runoff, most likely in the summer.
Des Moines has become an extreme example of the conflict over clean water between agriculture and cities in farm states with minimal regulation.
Iowa is a national leader in producing corn, soybeans, eggs and pork, and all that agricultural bounty results in enormous amounts of chemical fertilizer and animal waste pouring into waterways. The state's 23 million pigs produce waste that would be the equivalent of 83 million people — more than 25 times the state’s human population, according to University of Iowa research engineer Chris Jones.
Most of that manure is spread over Iowa’s 26 million acres of cropland, along with chemical fertilizers.
The natural and chemical fertilizers have helped Iowa increase its corn and soybean production by roughly 50 percent over the past 30 years, but much of it ends up in Iowa’s waterways, especially in areas of north-central Iowa that drain into the Des Moines and Raccoon rivers. That’s because the area’s farmland is relatively flat and relies on drainage systems called tiles that don’t allow excess fertilizer to filter through the soil but instead quickly pour it into streams, leading to high levels of nitrate and phosphorus.
Nitrates can cause so-called blue baby syndrome in which infants lose the ability to properly process oxygen into the bloodstream, giving their skin a bluish tint.