Cave Hills Timeline
Cave Hills Timeline
Rapid City Journal
1954 ? First major uranium mining claim filed in the Slim Buttes and Cave Hills.
1962 ? Major uranium mining operations in Harding County began.
1972 ? U.S. Forest Service unsuccessfully negotiated to institute rehabilitation measures. However, mining company Kerr-McGee agreed to relocate a segment of the Riley Pass Road and build dikes and dams at two locations.
1989 ? The Forest Service built five catch basins to trap sediment eroding from the mine site.
1990 ? The Forest Service cleaned two of the five ponds, removing about 6,791 cubic yards of sediment. An evaluation found high levels of radium 226 and elevated levels of arsenic, lead, iron and molybdenum and selenium. The Forest Service decided against cleanup because of reclamation costs of more than $2 million.
1996 ? Custer National Forest officials began reviewing soil samples analyzed in 1990 to determine if the area qualified for funds to clean up hazardous waste sites.
1997 ? The Forest Service set a deadline to clean five sediment ponds. Sediments from the ponds are stored on site. Concurrently, the Forest Service regional office conducted a search for mining companies responsible for mining in the area more than 30 years ago.
2002 ? Final site investigation recommended cleanup of hazardous waste in sediment ponds. The Forest Service began discussions with Kerr-McGee about cleanup of the sediment ponds, construction of a new pond and site remediation. Kerr-McGee declined.
2002 ? The Forest Service commissioned a draft engineering evaluation and cost analysis, which estimated total clean-up cost at $13.5 million to $14 million.
2002 ? Forest Service officials briefed Harding County Commissioners on hazards in the area and plans for remediation. They also talked to tribes known to use the area for ceremonies.
2002 ? Forest Service installed hazard-warning signs next to bluffs that showed elevated levels of hazardous materials.
2003 ? Forest Service began a further study of human health and safety hazards.
2004 ? Forest Service and Environmental Protection Agency officials work to clarify human health and safety hazards.
2004 ? Forest Service set a deadline to clean out sediment ponds and to build an additional sediment collection pond and diversion berm to capture sediment coming off bluffs.
2005 ? The Forest Service expects the final engineering evaluation and cost analysis within 30 days. It continues discussions with the state of South Dakota, EPA and tribes.
The Forest Service maintains that Kerr-McGee is responsible for site remediation for eight bluffs.
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