from: http://www.kttc.com/

ST. PAUL, Minn. (AP) — A spill at a sand mining facility in Wisconsin has dumped an unknown amount of sand and other sediment into the St. Croix (kroy) River and wetlands near the Minnesota border.

Wisconsin DNR officials tell Minnesota Public Radio News it’s too soon to know how much damage was done.

Conservation officials learned of the leak on April 22, when a hiker reported seeing cream-colored water in a creek flowing to the St. Croix River. DNR investigators traced the murky water back to a sand mining facility operated by Maple Grove-based Tiller Corp., where they located a leak in a holding pond.

The sand is mined for use by the petroleum industry to help extract underground natural gas and oil supplies in a controversial practice called hydraulic fracturing, or fracking.