Regulated industries in 2020 released at least 94.5 million pounds of potentially harmful nitrates into the Mississippi River basin. But some releases go untallied.
Agriculture creates most of the nitrate pollution, but consumers pay most of the cost, whether they drink from public wells or private ones.
Nitrate is a compound naturally found in plants and in vegetables and can be found in groundwater, depending on how much fertilizer and manure is applied to fields.
In the early 1990s, Jim Goodman and his wife began to worry about how the chemicals they were using on the farm might affect their children. The fourth-generation Wisconsin farmer decided to make the shift away from conventional farming at his Sauk County operation. Now certified organic, the farm includes 120 head of cattle on pasture, including 45 milk cows, and 300 acres of crops.
Levels of nitrate, one of the Wisconsin’s top drinking water contaminants, are increasing. Nitrate comes primarily from fertilizers, including manure, and puts infants and expectant mothers particularly at risk. A projected 94,000 households are drinking private well water with unsafe levels of nitrate. And many of them don’t even know it since few private well owners conduct regular testing.
Two new studies of private well water in Kewaunee County have linked contamination to fertilizer, livestock manure and human waste. “In these shallow bedrock areas, what you put on the surface, you will end up drinking eventually,” county conservationist Andy Wallander said.