RCRA Part B Hazardous Waste Permit:
Clean Harbors Grassy Mountain LLC

The Grassy Mountain Facility is a commercial, waste, treatment, storage, and disposal facility located near Knolls in Tooele County, Utah. It is approximately 80 miles west of Salt Lake City in the desert portion of the Bonneville basin near the Grassy Mountains. The site is one square mile and is remotely located. It is owned and operated by Clean Harbors.

Annual precipitation at the facility averages 6 inches, while the annual potential evaporation rate averages 40 inches. Relative humidity rarely exceeds 10 percent. There are no streams or rivers within a 40-mile radius of the facility; the nearest surface water is the Great Salt Lake, 30 miles to the northeast.

The facility is located on unconsolidated lacustrine sediments and salt deposits from former glacial Lake Bonneville. Depth to groundwater averages 10 feet. Due to high concentrations of dissolved solids (50,000-110,000 mg/L), the groundwater is not suitable for agricultural or domestic uses. Fresh water is trucked to the facility from Grantsville, Utah, nearly 60 miles away.

The Grassy Mountain Facility can manage liquid, solid or semisolid hazardous waste, PCBs, and non-hazardous industrial waste. The Grassy Mountain Facility has three active hazardous waste landfill cells, two of which are also authorized to dispose of PCB waste. There are ten closed landfill cells at the facility – three PCB cells, five hazardous waste cells, and two industrial waste cells.

A release of two low-level organic compounds from Industrial Waste Cell 1 was investigated from 1999-2003. A subsequent risk assessment concluded that risks to human health and the environment from the release are insignificant (below 1×10 -6 ).

The Director of the Division of Waste Management and Radiation Control reissued the facility’s hazardous waste Part B Permit on October 4, 2023.

Note that the online copy is not the official copy. Questions regarding the permit should be directed to the contacts identified below. The Compliance History for Clean Harbors Grassy Mountain lists any violations identified during inspections and the resolution reached.

Clean Harbors Grassy Mountain, LLC phone number is (435) 884-8900.

Comments or Questions

If you have any questions concerning the permitting or compliance of Clean Harbors Grassy Mountain Facility, please contact Kari Lundeen (klundeen@utah.gov) (385) 499-4923.

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