Region 8
Serving Colorado, Montana, North Dakota, South Dakota, Utah, Wyoming and 27 Tribal Nations
Superfund Program
National Information
Regional Information
Site Information
National Priorities List (NPL) History
Proposed Date
1/18/1994
Kennecott North Zone/Tailings
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Site Type: Proposed NPL City: Magna County: Salt Lake Street Address: 12000 West 2100 South Zip Code: 84044 EPA ID#: UTD070926822 Site ID#: 080654 Site Aliases: Kennecott Magna Soils, Kennecott Copper, Kennecott Tailings Congressional District(s): 03 |
Site Description
The Kennecott North Zone Site (the "Site") is an industrial area at the north end of the Oquirrh Mountains and at the south shore of Great Salt Lake, west of Salt Lake City, Utah. The Site is next to the community of Magna, which has a population of 15,000.
Interstate Highway I-80, state highways and rail lines pass through the Site. Recreation near the Site includes lakeshore swimming and wading, sunbathing and bird watching.
Since 1906, the Site has been used to process copper, lead, zinc, molybdenum, arsenic, gold and silver-bearing ores. The wastes produced contain hazardous substances, including heavy metals. Sludge and soils are contaminated, as are surface and groundwater that affect wetlands between the Site and the beach.
Kennecott Utah Copper Company is cleaning up the Site with oversight by state and federal agencies.
The cleanup approach for the Site has been addressed in stages: early actions and long-term phases. The first actions focused on removal of surface contamination found during modernization of the smelter and refinery. The second early action involved soils in Magna. The analytical results indicated that these soils do not pose a health threat to the public.
The long-term phases focus on cleanup of the wastewater treatment plant sludge ponds, wetlands and soils. Methods of groundwater treatment for the Site are currently being investigated.
Site Risk
Many years of smelting and processing ore mined in the central Oquirrh Mountain area, 20 miles south of the Site, left extensive mine wastes. These wastes occur as sludge ponds, soils, slag piles and other smelter waste; as contaminated surface water in streams, ditches, ponds and wetlands; and as contaminated groundwater.
Lead, arsenic and selenium are the potential contaminants of concern. These metals have been linked with various types of cancer, poisoning, high blood pressure, gastrointestinal disorders and decreased body weight, if people are exposed to them over long periods of time. Birds are particularly sensitive to selenium.
EPA's involvement at the Site began in 1991. Kennecott conducted several studies with state and EPA oversight.
The Site was proposed for the Superfund National Priorities List (NPL) in January 1994. In 1995, Kennecott, EPA and the State of Utah signed an agreement, saying that Kennecott will continue the cleanups and EPA will defer final listing on the NPL.
| Media Affected | Contaminants | Source of Contamination |
| Soil, groundwater, surface water, sludge | Lead, arsenic, selenium | Wastes from ore smelting and processing |
Cleanup Progress
Sludge-pond material, produced by the treatment of processing waters from the refinery and smelter, contains high levels of lead, arsenic and selenium. These sludges were excavated, mixed with contaminated soils from the refinery and smelter, and placed in an on-Site repository. Removal of surface wastes was completed in 2001.
The U.S. Army Corps of Engineers issued a Clean Water Act Permit in 1996 to expand the Kennecott tailings ponds. It includes cleanup provisions in the area.
The U.S. Bureau of Reclamation (BOR), with EPA supervision, tested soils for high levels of heavy metals the Great Salt Lake beaches. BOR sampled southern lake beaches and across drainages flowing through the beaches from nearby milling, smelting and refining operations. Beach sands do not pose a threat to the public.
A groundwater plume of elevated selenium was found; the selenium is entering nearby wetlands from springs and seeps. The spring water has been rerouted around the wetland as an interim measure. Pilot treatment plant experiments for treating the selenium in the groundwater are under way. Excavation of contaminated sediments in the wetlands was completed in 2001.
Site Documents
Note: the document below is a VERY LARGE PDF FILE (About PDF files)
Contacts
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EPA Rebecca Thomas Peggy Linn |
Utah Doug Bacon Dave Allison |
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View Documents at: EPA Superfund Records Center Magna Public Library |