There was a spill at Cotter Corp.’s defunct uranium mill in central Colorado — one of the nation’s slowest Superfund cleanups.
A pipeline leaked about 1,800 gallons last week on Cotter’s 2,538-acre property uphill from Cañon City and the Arkansas River.
Well tests in July found water in the waste pipeline area contained elevated uranium (577 parts per billion, above a 30 ppb health standard) and molybdenum (1840 ppb, above a 100 ppb standard), said Colorado health officials.
This spill was the latest of at least five since 2010. Federal authorities in 1984 declared an environmental disaster and launched a Superfund cleanup.
From 1958 to 1978, Cotter processed uranium for nuclear weapons and fuel at the mill, discharging liquid waste, including radioactive material and heavy metals, into 11 unlined ponds. The ponds ended up replaced in 1982 with lined waste impoundments.
Earthen dams and a pump at the low end of Cotter’s property, about 1½ miles from Cañon City’s Lincoln Park neighborhood, trap water and move it to a pond for treatment.
Colorado Department of Public Health and Environment officials last week issued a notice of the spill, saying Cotter reported containment. A report from Cotter, sent Monday, said a coupler on a 6-inch pipeline broke Nov. 24 or early Nov. 25 and workers fixed it.
Cotter manager Stephen Cohen said it’s unlikely this spill will worsen contamination of groundwater.
“We’re going to have to take a fresh look at what’s going on, in order to prepare a remedial investigation report” for a cleanup, Cohen said.
Cotter is a subsidiary of San Diego-based defense contractor General Atomics.