The Republican chairman of a congressional panel investigating a 3-million-gallon spill of toxic wastewater from an inactive Colorado gold mine said Tuesday the mine was purposely breached by a government cleanup team.
The assertion by House Natural Resources Committee Chairman Rob Bishop of Utah contradicts claims by the Obama administration that the cleanup team was doing only preparatory work at the Gold King mine.
Once it was breached, wastewater loaded with lead, arsenic and other contaminants fouled downstream rivers in Colorado, New Mexico and Utah.
Bishop cited an email in which an Interior Department official said the spill last August occurred when the U.S. Environmental Protection Agency team used an excavator to remove a dirt and rock "plug" blocking the mine's entrance.
The plug was holding back pressurized wastewater that had accumulated for years inside the mine north of Durango.
"There was nothing unintentional about EPA's actions with regard to breaching the mine. They fully intended to dig out the plug and breach it," Bishop said during an Interior Department Budget hearing.
Interior Secretary Sally Jewell said under questioning from Bishop that she stood by her earlier testimony the EPA was preparing the site for future work.
"It was an accident," Jewell said.
The spill forced the shutdown of public water supplies and left farmers on the Navajo reservation and elsewhere worried about long-term impacts to their irrigation supplies.
The email cited by Bishop was sent two days after the spill by Brent Lewis, an abandoned mines expert from Interior's Bureau of Land Management.
"EPA's plan was to slowly drain and treat enough mine water in order to access the inner mine working and assess options for controlling its discharge," Lewis wrote on Aug. 7. "While removing a small portion of the natural plug, the material catastrophically gave way and released the mine water."
Lewis did not immediately return a call from The Associated Press seeking comment.
EPA officials have said for months that the cleanup team planned to stop their work before breaching the plug and come back later with additional equipment to drain the mine.
Agency spokeswoman Nancy Grantham repeated that claim Tuesday in response to questions about the Lewis email. The excavation work, she said, was intended "to assess the site conditions and to help prepare for a decision on future work."
A review of the accident by the Interior Department reached a similar conclusion.
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