The 4,525-acre US Magnesium site is located in Tooele County, Utah. In 1972, US Magnesium began magnesium production at the site. The production process involves isolating naturally occurring magnesium from the Great Salt Lake and then treating the dissolved magnesium. Facility operations and waste disposal practices contaminated soil, air, surface water and groundwater with hazardous chemicals. In addition to threatening the health of US Magnesium workers, the contamination poses a threat to birds and wildlife around Great Salt Lake. Site investigations are assessing the nature and extent of contamination and exploring appropriate cleanup options.