Superfund Information Systems: Site Profile

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The US Magnesium Superfund site is located adjacent to the Great Salt Lake in Toole County, Utah, 33 miles to the north of Grantsville and 40 miles to the west of Salt Lake City. The sparsely populated, 4,525-acre site includes the US Magnesium facility and surrounding areas of waste disposal. The facility has been producing magnesium at the site since 1972. The production process involves isolating magnesium chloride salts from the Great Salt Lake and then extracting the magnesium by electrolysis. 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.

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What Is Being Done to Clean Up the Site?

EPA continues to investigate the nature and extent of the environmental contamination at the US Magnesium Superfund site as part of the remedial investigation. Actions necessary to protect human health and the environment will be determined later in the Superfund process. The first steps in the Superfund process are the remedial investigation to determine the nature and extent of contamination and the associated feasibility study to evaluate cleanup alternatives based on data collected in the remedial investigation.

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What Is the Current Site Status?

For best management purposes, EPA divided the US Magnesium Superfund site into two operable units: Operable Unit 1 (OU1) comprises soil, sediment, and water across the site, and Operable Unit 2 (OU2) is air within the 5-mile study area. The site was then further divided into 18 Preliminary Remedial Investigation Areas (PRIs).

In September 2013, EPA issued the Phase 1A Remedial Investigation Sampling and Analysis Plan to identify chemicals of potential concern in soils, sediment, solid waste, water and air, and receptor surveys (Phase 1A SAP). The Phase 1A SAP is the first phase in a four-phase approach to the Remedial Investigation. Site activities to-date, as guided by the Phase 1A SAP include:

  • All sampling of soils, sediment, solid waste, and water is complete in the Outer PRI areas, and the Outer PRI Findings Report is pending.
  • EPA finalized the Phase 1A Air Sampling and Analysis Plan in 2014 to identify chronic airborne contaminants being released from the facility. Sampling indicated that chlorine and hydrocholoric acid are the two chemicals that need to be evaluated in more detail. EPA and US Magnesium, LLC contractors are developing a new Air Sampling and Analysis Plan for acute exposures to these two contaminants at the site.
  • EPA finalized the Phase 1A-B Sampling and Analysis Plan in 2015 which guides initial sampling investigations for soils, sediment, solid waste, and water in the inner PRIs. Crews completed this sampling effort at the end of 2015. A results report is pending.

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