Seitz/St. Croix 360

The town hall in rural Emerald Township in eastern St. Croix County, Wis. happens to be within sight of one of the biggest industrial livestock facilities in western Wisconsin. A half-mile down the two-lane road, Emerald Sky Dairy’s two huge barns are home to about 1,500 cows that produce 14,000 gallons of milk per day — and a lot of manure.l

All the manure is used on nearby agriculture fields as fertilizer. The soil and plants can only absorb so much nitrate, though, and such spreading can lead to pollution of both surface water, like lakes and streams, and groundwater, the aquifers that most of Emerald Sky’s neighbors depend on for drinking.

Now, the Town of Emerald has learned that the amount of nitrate, a chemical often connected to large-scale manure spreading, in its well water is more than four times higher than what is considered safe. It has increased five-fold since the well was dug in 2007.

The test results show both an extreme case of contamination, and reflects a growing problem across the county, and throughout Wisconsin.

“The Emerald Town Hall well has some of the highest groundwater nitrate that have been observed through the County’s [Citizen Groundwater Monitoring Program],” said Cole Webster, Water Resource and Outreach Specialist for St. Croix County.

Both the Centers for Disease Control and the state of Wisconsin say no one should drink water with more than 10 mg per liter of nitrate.