10 mines suspend cleanup in wake of Colorado spill
BILLINGS, Mont. — Site investigations and some cleanup work at 10 polluted mining complexes in four states were suspended because of conditions similar to those that led to a huge wastewater blowout from an inactive Colorado gold mine, U.S. Environmental Protection Agency officials said.
The sites include three in California, four in Colorado, two in Montana and one in Missouri, according to details obtained by the Associated Press.
They have the potential for contaminated water to build up inside mine workings, EPA Assistant Administrator Mathy Stanislaus said. That would set the stage for a possible spill such as last month’s near Silverton, Colo., where an EPA team triggered a 3 million gallon blowout of toxic sludge while doing excavation work on the inactive Gold King Mine.
The accident fouled rivers in three states and attracted harsh criticism of the EPA for not being prepared despite warnings that such a spill could happen.
“We want to take extra caution before we initiate any work,” Stanislaus said of the work suspensions. Some the mines were abandoned decades ago and have grown more unstable over time, raising the risk of an accident.
The stop-work order was issued last month but officials for weeks refused to disclose specifics.
Cleanup efforts on some of the mines have been going on for years yet remain unfinished, underscoring the complexity of a long-running attempt to address an estimated 500,000 abandoned mines across the U.S. Work on others was in the early stages.
In a report to Congress delivered Friday, the Government Accountability Office said federal agencies identified thousands of contaminated mine sites in recent years — even as their attempts to assess what harm is being done to people and the environment have lagged.
Further investigations were needed to gauge the danger posed by the 10 mining complexes under the suspension before work could safely resume, according to EPA documents.
The Aug. 12 stop-work order from EPA Administrator Gina McCarthy did not apply to sites where halting operations would pose a threat to people or increase the potential for harm to the environment, according to EPA documents.
Also exempted were portions of the 10 stopped projects where construction already was completed, such as treatment systems for contaminated water that pours from many abandoned mine shafts.
That’s the case for two sites in northern California — the Leviathan sulfur mine near Markleeville (Alpine County) and the Iron Mountain metals mine near Redding. Water continues to be collected at the sites, to be treated and then discharged.