The U.S. Environmental Protection Agency officially announced the proposal Wednesday as a necessary step before ordering the company to pay for a multimillion-dollar cleanup.
EPA says hazardous chemical waste at the company's Tooele County processing plant endangers workers, their families, waterfowl and the environment.
The agency says hazards include dioxins, metals, acidic wastewater and polychlorinated biphenyls (PCBs). Also in the mix: hexachlorobenzene (HCB), a banned fungicide that causes cancer.
U.S. Magnesium already is objecting to EPA's move. A week ago, the company accused the agency of failing to follow its own regulations and incorrectly interpreting science and the law.
U.S. Magnesium, about 40 miles west of Salt Lake City adjacent to the Great Salt Lake, topped the nation's worst-polluter lists in the 1980s. The plant spent about $50 million to upgrade its operations, which resulted in a 60 percent drop in the amount of hazardous emissions.
No longer on the nation's top-100 toxic list, U.S. Magnesium ranks as Utah's fifth-worst polluter.
The company and the public will have 60 days to comment on whether the 4,525-acre site should be added to the Superfund list. Utah now has 24 Superfund sites in various stages of cleanup.
EPA also is considering a legal review of U.S. District Judge Dee Benson's ruling last year that gutted the federal agency's $1 billion lawsuit against the company.
Benson largely sided with claims that Congress granted the magnesium plant an exemption from a federal hazardous-waste law. Worried that the ruling could set a precedent in similar cases, EPA might try to have Benson's ruling overturned.
