Wisconsin Faces Rising Nitrate Contamination from Agriculture

Wisconsin is confronting a growing public health concern as agricultural runoff continues to contaminate drinking water with nitrates. A report by the Alliance for Great Lakes and Clean Wisconsin highlights widespread nitrate pollution from fertilizer, manure, and biosolids, with levels in some streams exceeding 30 mg/L—three times the EPA’s recommended limit of 10 mg/L. Exposure during pregnancy increases risks of low birth weight and pre-term birth, and studies suggest potential links to cancer.

The report estimates that over 16 million pounds of excess nitrogen were applied to Wisconsin fields in 2022 alone. Municipal water systems have spent over $40 million on remediation, with costs increasingly passed to consumers. Advocates are urging stronger enforcement, updated water standards, expanded private well support, and broader agricultural participation to implement effective solutions. They call for policy reforms to protect public health, safeguard water quality, and sustain farming practices across Wisconsin and the Great Lakes region.

20-09-2025