The Bureau of Reclamation is recommending that mine tailings, which would be located under the water of Jordanelle Reservoir if left alone, be moved to a landfill north of the lake.
A draft environmental assessment of the recommendation was released this week. Public comment on the draft must be submitted to the bu-reau by March 30.Moving the Olson/Neihart mine tailings to a 20-acre landfill site above Jordanelle's future high water mark and near the relocated U-40 would reduce the potential for leaching metals into the reservoir's water, the bureau said.
Other alternatives rejected by the bureau include no action; stabilizing the tailings but leaving them at their present location; consolidating the tailings with those adjacent to the landfill site; and moving the tailings to other sites.
The tailings were once placed on the federal Environmental Protection Agency's Superfund list, the bureau said, and are still considered a potential hazard containing high concentrations of arsenic, cadmium, copper, lead and zinc.
According to the assessment, the tailings would be dried and treated with cement before being transported to a lined and capped landfill designed to prevent seepage into ground and surface water, the bureau said.
Cost of the recommended tailings cleanup is between $10 million and $25 million.