A company named Empire Building Investments proposes drilling two wells into the Mount Simon Sandstone aquifer in Dakota County, Minnesota. These wells would extract annually up to 500 million gallons of groundwater to be shipped to users in the southwestern U.S. While this is being now assessed by Minnesota agencies, it should also raise alarm bells in Wisconsin. The Mount Simon Sandstone is a permeable rock formation underlying much of western Wisconsin. It is named for exposures in Eau Claire, where it crops out at the surface. This part of Wisconsin is a recharge area for the aquifer. The formation dips west at a low angle into Minnesota and is generally deep underground by the state line.
There is lots of groundwater in this aquifer, but no aquifer is immune from exhaustion if over-exploited. In addition, much of this water entered the aquifer thousands of years ago in a climate very different from what we have now and from what we can expect in the future. This aquifer is a wonderful resource that can help buffer state residents and agriculture from climate change.
If this request is successful, it would open the door to many more, and a significant removal of precious ground water from our region. Drawing down the resource in Minnesota would inevitably affect this aquifer in Wisconsin, as groundwater recognizes no state line.
Even if Minnesota agencies refuse to allow this, companies in Wisconsin could propose similar plans. We need to be prepared to resist this attack on this critical regional resource.
Part of the preparation is being sure Wisconsin has appropriate legislation in place to intelligently evaluate such proposed withdrawals. Another part is demanding a say in what happens in other states sharing in this aquifer.
William S. Cordua
William Cordua is an emeritus professor of geology at the University of Wisconsin.