The Des Moines River, a tributary of the Mississippi, runs about 525 miles from southern Minnesota across Iowa from northwest to southeast. The photo shows the river just upstream of Ottumwa, Iowa, which is about 84 miles southeast of Des Moines.
Photo: Wikipedia.org, public domain. Source: U.S. Geological Survey

Des Moines Water Works (DMWW) gave formal notice the first week of January that it will sue three Iowa upstream counties (Sac, Buena Vista and Calhoun) for allowing high nitrate levels from fertilizers to run into the Raccoon and Des Moines rivers. It's DMWW assertion that the county governments can be held legally responsible for the pollution that their underground pipes carry from the farm fields to the rivers.

DMWW treats the Raccoon and Des Moines River water to provide drinking water for over half a million people in Des Moines and other surrounding communities. DMWW reports that filtering out those nitrates cost $900,000 in 2013.

DMWW explains that one concern of high nitrate levels in drinking water is mehtemoglobienemia (blue baby syndrome), a condition that affects the stomach acid of infants less than six months old. Nitrates cause an increase in bacteria, which compete with red blood cells for oxygen. The Center for Disease Control specifies that heating or boiling water will not remove nitrate, and can actually increase nitrate level concentrations due to water evaporation.

Nitrates in water bodies can promote algae bloom and cyanobacteria, which can use up oxygen and block light from filtering into deeper water, affecting both plant and fish life.

One solution for farmers, albeit it pricey, is to build sediment-trapping ponds or wetlands to capture the water from the field drainage. The state and federal government is offering financial incentives to build the pond traps, but the program has over a two-year waiting list.

"We need to get down to specific steps that they need to take. If they aren't willing, we'll see them in federal court," Stowe said.