Farm runoff is driving high nitrate levels in water around Iowa’s largest city, taxing the drinking water system and raising concerns about potential health risks for people exposed to the pollutant.
EPA stepped in last year, under the Biden administration, to classify parts of seven rivers used for drinking as “impaired” — meaning heavily polluted — with nitrate. The nitrogen compound can cause harmful algal blooms and may increase the risk of certain cancers over a lifetime of human exposure.
Supported by Iowa’s biggest drinking water utility, the designation would have put pressure on the state to develop pollution reduction plans. This past summer, nitrate levels were so high around Des Moines that residents were told not to water their lawns to ensure treatment facilities could produce adequate drinking supplies in compliance with federal regulations.
But EPA under the Trump administration reversed last year’s decision, concluding that the seven rivers added to Iowa’s impaired waters list were not impaired for nitrate and nitrite — a similar compound — after all.
