A coalition of 83 organizations is urging federal regulators to take emergency action on nitrate contamination in drinking water, citing growing health concerns tied to agricultural runoff. The groups sent a letter to the Department of Health and Human Services and the Environmental Protection Agency, calling for stronger oversight and enforcement. The push follows new research showing high nitrate levels in waterways, particularly in Iowa, where contamination has been linked to rising cancer rates. Advocates say industrial agriculture, including fertilizer runoff and livestock operations, is a major contributor. A recent report found roughly one in five Americans may be exposed to nitrate-contaminated drinking water, raising broader national concerns. “This report showing the link between nitrate-contaminated tap water and cancer rates in Iowa should be a wake-up call for the whole country,” said Nancy Stoner, a senior attorney for the Environmental Law & Policy Center.