Friday, August 28, 2015

EPA: Waste pressure evidently never checked before Colorado mine spill

Dangerously high levels of water pressure behind the collapsed opening of the Gold King Mine were never checked by the Environmental Protection Agency, in part because of cost and time concerns. The revelations came Wednesday as the EPA released an internal review of a massive Aug. 5 blowout at the mine above Silverton. The report called an underestimation of the pressure the most significant factor leading to the spill. According to the report, had crews drilled into the mine's collapsed opening, as they had done at a nearby site, they "may have been able to discover the pressurized conditions that turned out to cause the blowout." According to the review, drilling into the collapsed opening would have been "quite costly" and taken more time because of soil and rock conditions at the site. The review says crews believed that because water was leaking from the Gold King and based on seep levels above its opening, a buildup of pressure was "less likely." Because of those signs, officials say, drilling appeared to be unnecessary. EPA supervisor Hays Griswold, who was at the scene of the blowout Aug. 5, told The Denver Post in an interview this month that conditions in the mine were worse than anticipated. "Nobody expected (the acid water backed up in the mine) to be that high," he said. The report says, however, that decreased wastewater flows from the mine, which had been leaching for years, could have offered a clue to the pressurization. Also, a June 2014 task order about work at the mine said "conditions may exist that could result in a blowout of the blockages." The inability to obtain an actual measurement of the mine water pressure behind the mine's blocked opening "seems to be a primary issue," according to the review. It went on to say that if the pressure information had been obtained, other steps could have been considered. It did not elaborate on what those steps could have been...more

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