The Department of Energys latest inspection found that a site in Bodo Canyon where 2.5 million cubic yards of radioactive mill tailings from Durangos uranium-processing era is buried suffered some vandalism, but it has no toxic-drainage problems.
Concentrations of uranium, selenium and molybdenum in seven monitoring wells are within bounds, the 2010 report said.
A spike in the concentration of uranium in one well in 2009 has dropped as a result of remedial work, the report said. The 0.11 parts per million of uranium in November 2009 are now at 0.075 ppm, below the limit of 0.077 ppm.
The limits for selenium and molybdenum are 0.042 ppm and 0.22 ppm, respectively. In 2010, the level of selenium was 0.0062 ppm and the level of molybdenum, less than 0.002 ppm.
The disposal cell and all associated surface-water diversion and drainage structures were in good condition and functioning as designed, the report said. The water level in the disposal cell has dropped, which satisfies criteria for the permanent closure of the transient drainage water-collection system.
But theft and damage to signs continues, the report said. Erosion has undercut the bases of two perimeter signs, but they remain stable.
The Bodo Canyon disposal site is located 3.5 miles southwest of Durango. It covers 120 acres, 42 of which constitute the cell where waste from a mill that processed uranium in Durango for all but three years from 1942 to 1963 is buried.
The disposal cell, 2,400 feet long and 1,300 feet wide, is covered with 7 feet of layered protective materials a radon membrane, sand-filter drain and clay mat and rock to protect against invasion of vegetation and a rock/soil cap.
The Department of Energy is studying the possibility of authorizing the construction of a photovoltaic array on top of the cell to generate electricity.
La Plata Electric Association is a possible operator of the solar project.