WHITEHALL, Wis. (AP) — Wisconsin officials are working to determine the environmental impact of releasing millions of gallons of sludge from a settling pond to rescue a trapped sand mine worker.
A contractor’s bulldozer slid into a pond Monday at the Hi-Crush mine in Whitehall, The La Crosse Tribune reported. The pond was 12 to 15 feet deep, company officials said.
Operator Robbie Gunderson was trapped inside the cab for hours as rescuers tried reaching him. Workers used excavators to release the pond’s contents after rescuers recommended lowering the water level, said Scott Preston, chief operating officer at Hi-Crush. About 10 million gallons of orange water and mud spilled into a nearby Trempealeau River tributary.
The pond’s contents was mostly water, silt, clay and sand, though it could contain trace elements of polyacrylamide, a chemical used to remove silt from the water, said Jeff Johnson, the company’s environmental compliance manager.
Trempealeau County’s land management department is waiting for tests to determine what’s in the water and if it’s dangerous, said George Brandt, county supervisor.
The Wisconsin Department of Natural Resources and the Fish and Wildlife Service are also assisting in the investigation.
“Any time something foreign, chemicals get into the river it’s a concern,” said Sabrina Chandler, manager of the wildlife service’s Upper Mississippi National Fish and Wildlife Refuge. “At this point we don’t know what the implications may be.”
A sediment plume could potentially smother animals and plants that live in the river, according to Roger Haro, a professor of biology in the River Studies program at the University of Wisconsin-La Crosse.
Preston said Hi-Crush has installed barriers to contain silt as it works to clean the surrounding land.