The Environmental Protection Agency says cleanup work on mines throughout the country remains on hold as its regional offices scurry to identify other sites at risk of blowing out like the Gold King Mine did .
David Gray, an EPA spokesman, said Monday the agency is specifically looking for mines with similarities to the Gold King, which spilled 3 million gallons of contaminants on Aug. 5 above Silverton.
He said the survey is being done “to identify any potential immediate threats and to consider appropriate response actions.”
The EPA late Friday showing the agency knew the Gold King Mine was at risk for blowout at least 14 months before the massive release. The spill sent yellow-orange sludge cascading into a tributary of the Animas River and prompted emergencies in three states and .
According to the EPA, it is undertaking an “extensive file review” to see if any — — Colorado mines have also been documented by the agency as being at risk for blowout. The EPA said Monday it of mines it is working at in Colorado and throughout the nation.
“We do not know of documentation showing blow-out risk at other mines in Colorado that can be shared with you immediately,” the EPA said in a statement sent to The Denver Post.
A June 2014 task order for the Gold King documented blow-out risks and called the mine a “time critical” site.
“Conditions may exist that could result in a blowout of the blockages and cause a release of large volumes of contaminated mine waters and sediment from inside the mine, which contain concentrated heavy metals,” a task order said.
Experts say there is no way to know exactly how many other mines in Colorado are at risk for blowing out.
“(Blowouts are possible) when you’ve got mine workings that go up multiple levels,” said Peter Butler, a coordinator for the Animas River Stakeholders Group. “You’ve got the ability to build up a lot more water pressure.”
Butler said in Colorado there are “quite a few” such mines, but that they don’t represent the majority of tunnels in the state. In the Upper Animas River Mining District where the Gold King sits, Butler says he knows of four blowouts in the last 20 years.
All of them happened naturally and were much smaller than the Gold King’s massive release, he said.
“I think most of the mines that have a potential for blowout are not being worked on,” he said. “They are just sitting there.”
Ron Cohen, an associate professor of civil and environmental engineering at the Colorado School of Mines, said blockages holding back walls of wastewater are fragile and can burst with little effort.
“When you have these unstable blockages in these mine workings, you never know what’s going to happen,” he said. “You can be repairing a road in front of the mine portal and just those vibrations can set something off.”
Cohen explained that while blowouts can happen both naturally and with human interaction, locally most happen from the latter. He pointed to the into Clear Creek after miners using shovels inadvertently released backed up contaminants.
The spill lasted six hours and, as in the case of the Gold King breach, turned water downstream orange.
“These places, they’re collapsed,” Cohen said of the difficult task ahead of the EPA in trying to identify mines that are at risk for blowing out. “There’s absolutely no documentation of their workings. There is a lot of guesswork involved.”
Hays Griswold, an EPA supervisor who was at the scene of the Gold King blowout Aug. 5, in an interview with The Post earlier this month said he was aware of another mine in the area whose owner expressed fears of a blowout.
That mine lacks multiple levels but has a long tunnel.
“It would be messy if it blew out,” Steve Fearn, another coordinator with the Animas stakeholders group, said of the site. “It probably wouldn’t be nearly as big as the Gold King, (but) it wouldn’t be a good situation.”
Fearn, who was president of the Gold King Mine Corp. — which owned the Gold King — in the late 1990s said while the possibility of major blowouts isn’t an immediate crisis, the danger represents “a time-bomb situation.”
“There are probably only a few mines that represent a significant risk,” he said.
Jesse Paul: 303-954-1733, jpaul@denverpost.com or twitter.com/JesseAPaul
Gold king mine
The Gold King was in and out of operation between 1887 and 1922, during which is shipped 711,144 tons of gold and silver ore, according to the EPA. It is currently held by the Golden-based San Juan Corp. and had a permit for operation until 2005.
