US Magnesium LLC — Rowley plant
Large load · 12819 North Skull Valley Rd, Grantsville, UT
US Magnesium LLC operates a Great Salt Lake magnesium plant at Rowley in Tooele County, Utah, that harvests salts to produce primary magnesium metal, chlorine derivatives and lithium carbonate. PacifiCorp promised to provide up to 125 MW of power under the electric service agreement reviewed in 2021, and the plant has been an interruptible electric service customer of Rocky Mountain Power. Magnesium production stopped in September 2022, and the company filed for Chapter 11 in September 2025.
Overview
- Contracted demand
- 125 MW
- operating · Jan 26, 2021
US Magnesium harvests salts from the Great Salt Lake to produce primary magnesium metal, chlorine derivatives and lithium carbonate. The company stopped magnesium production in September 2022, and equipment failures the previous year had curtailed production even earlier. In late 2024 it announced it was stopping lithium mining from its waste piles and laying off 186 workers, and it said it did not have any immediate plans to restart magnesium operations. The company states it has the capacity to produce 63,500 metric tons per year of primary magnesium and 9,000 metric tons per year of lithium carbonate.
Profile
- Electricity and grid
- US Magnesium has been an interruptible electric service customer of RMP for nearly forty years. The Rowley Substation point of delivery is the 138-kV side of the 138 to 13.8-kV transformers. The 2004 electric service agreement set an Interruptible Contract Demand of 125 MW and used an estimated monthly Demand of 85 MW for prepayment calculations, and a 2021 filing says PacifiCorp promises to provide US Mag with up to 125 MW of power. Onsite, a 2010 filing described a gas-fired generating facility with a nameplate capacity rating of 45 megawatts, and a 2021 filing described three 12.4 megawatt gas-fired generation units with a nameplate capacity of 37.2 MW. A 2020 application kept in place the current day-ahead curtailment structure, and the Operating Reserves billing credit stayed at $4.01/kilowatt-month. A 2005 news report said the plant uses a peak of about 95 megawatts, and in 2022 testimony US Magnesium's on-site generation capacity was approximately 32 MW.
Facility
- Activity
- Primary magnesium metal, chlorine derivatives and lithium carbonate from Great Salt Lake salts
- Industry
- Industrial
- Site type
- Facility
- Operating status
- Idled
Reported Dec 12, 2024
- Demand flexibility
Permits and agreements
- Agreement
- Operating Reserves billing credit of $4.01/kilowatt-month
Related records
Timeline
- Sep 1, 2025
- US Magnesium filed for Chapter 11 protection.
SSG Advises US Magnesium in the Sale of Select Unencumbered Assets to the Utah Division of Forestry, Fire, and State Lands – SSG Capital Advisors, LLC