Mary Jane Koch stands near the site of her family’s former summer cottage on Lake Wisconsin. For decades, the Badger Army Ammunition Plant dumped its waste into the lake, an impoundment of the Wisconsin River. The Army has since removed tons of heavy metals from the lake and has proposed building a public water system to provide clean drinking water to area residents.

Costs, water pollution remain at closed Badger Army Ammunition Plant

Decades of toxic waste disposal at the Badger Army Ammunition Plant — including pouring millions of gallons a day of polluted water into Lake Wisconsin — have contaminated some nearby residents’ drinking water and raised concerns about the long-term effects on their health. But help may be on the way.

Nitrogen-based fertilizers applied to corn and other crops in Wisconsin is partially to blame for unsafe levels of nitrate found in wells around the state, researchers say.

What is nitrate?

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.

Sauk County farmer Jim Goodman, seen here at the farmers’ market in the village of Dane, said he believes Wisconsin’s nitrate problem has been exacerbated by “too many animals in too small a space” and the government’s failure to enforce pollution laws. Goodman is an organic farmer who uses nitrogen-fixing cover crops and manure rather than artificial fertilizers.

Going organic: One farmer’s fight against contaminants in the groundwater

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.

Land use is a factor boosting the level of nitrate in the water in Wisconsin. In the Upper Midwest, millions of acres of grassland — which leaches little nitrogen into aquifers — have been converted into fields of corn, soy and other crops since 2008, according to University of Wisconsin-Madison researchers. Here, a farmer harvests corn near Blair in Trempealeau County.

Nitrate in water widespread, current rules no match for it

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.

Frank Michna buys bottled water for drinking and cooking in his Caledonia home because of high levels of molybdenum and boron in his well.

Safe, clean drinking water eludes many Wisconsinites

Hundreds of thousands of Wisconsin’s 5.8 million residents are at risk of consuming drinking water tainted with substances including lead, nitrate, disease-causing bacteria and viruses, naturally occurring heavy metals and other contaminants, the Wisconsin Center for Investigative Journalism has found.

Fly ash samples

‘Beneficial reuse’ of coal ash could contaminate drinking water statewide

It’s not a good sign when even the dogs won’t drink your tap water. “They sniff it and then drink the bottled water we pour,” said Frank Michna of Caledonia, one of hundreds of southeastern Wisconsin residents whose wells are contaminated by pollutants that may be coming from buried coal ash.