(Des Moines, IA) -- A two-year research study commissioned by Polk County on water quality in the Des Moines and Raccoon Rivers finds that nitrate levels are currently within the EPA’s safe drinking water standards.
“We shouldn’t take too much comfort in that,” said Professor Jerry Schnoor of the University of Iowa. “Recent health studies indicate there can be effects at much lower concentrations, maybe five or even three milligrams per liter.”
Schnoor was one of 16 scientists who participated in the study, which was presented to hundreds of attendees at Drake University last night and even more online. The Central Iowa Source Water Research Assessment is a 227-page report detailing the factors impacting water quality in both rivers.
While Schnoor commended Central Iowa Water Works for keeping drinking water within EPA limits, he warned that even those limits may not be safe. Lower concentrations of nitrates have been linked to serious health risks, including low oxygen levels in infants, birth defects, and certain types of cancer.
“Of more than 2,000 rivers recently surveyed, we rank in the top one percent nationwide for nitrate concentrations, a very dubious distinction,” Schnoor said.
Scientists reported that around 80 percent of the nitrates found in Iowa’s waters come from agriculture, with 40 percent of that attributed to fertilizer use.
Over the past several months, both the Raccoon and Des Moines Rivers have recorded significantly elevated nitrate levels. Earlier this summer, the Raccoon River reached nearly 18 milligrams per liter, well above the EPA’s maximum contaminant level of 10 milligrams per liter.
A link to the full report is available at The Central Iowa Source Water Research Assessment.