US Magnesium LLC said it will challenge the U.S. Environmental Protection Agency's addition of its site in Tooele County, Utah, to the National Priorities List (NPL) of Superfund sites.

The designation makes the cleanup of the area surrounding the magnesium plant a high priority and would enable the EPA and the Utah Department of Environmental Quality to compel US Mag to pay for some or the entire cleanup.

"The removal and containment of site contaminants will reduce health risks for those that work in the area, and will directly benefit wildlife, water quality and the overall health of the Great Salt Lake ecosystem," Gwen...