The dustings of snow on top of the San Juan Mountains only signify the urgency to which the Environmental Protection Agency looks to stabilize the discharge of acid mine drainage at the Gold King Mine before winter sets in.
On Friday, EPA officials expect to finally turn on operations at a temporary treatment facility that will last the winter. The retention ponds built in the immediate aftermath of the Aug. 5 blowout were located in an avalanche zone and were never intended to operate beyond a few weeks.
The treatment facility, in an area 10 miles north of Silverton, will begin to take in acid mine drainage from the Gold King Mine, which is discharging about 500 to 600 gallons of the mine wastewater per minute.
A 4,800-foot pipe from the portal of the Gold King Mine will direct the drainage down a steep slope into the treatment system. The water is then treated with lime to raise the pH and systemized to separate heavy metals.
Lime treatment is the most effective system for handling acid mine drainage, but it is also regarded as a costly one, which leaves behind solid waste that operators are tasked with handling.
“The solid disposal is always a challenge,” said Steve Way, on-scene coordinator for the EPA. “That’s why treatment with lime addition is something any corporation, any agency wants to avoid if they can. It’s an expensive treatment process.”
Way said the EPA is still weighing its options on how to manage the solid waste, but it’s likely the material will be stored on site. He estimated that the facility will generate about 2,500 cubic yards over the next 10 to 12 months.
The water released from the facility over winter into Cement Creek, a tributary of the Animas River, will reduce the metals of concern – namely zinc, copper and cadmium – 90 to 95 percent, at minimum, Way said.
However, the site at this time is taking in acid mine drainage from only the Gold King Mine. The adjacent Red and Bonita and Mogul mines, as well as the American Tunnel, together are still discharging about 500 gallons per minute into Cement Creek. Down the line, Way said there is an option to collect that water into the system.
And despite the launch of the new treatment system, the Animas River is still not expected to meet water-quality standards. An entire network of abandoned, leaking mines poses a more complicated and expensive problem to environmental experts.
“These particular mines are one set of sources,” Way said. “They are not the only contributing metal source in this system. So the long-term, bigger picture is much more complicated. This is one step in that direction.”
Way couldn’t comment on where exactly those discussions are. He said the EPA is still working with state and local officials, as well as affected communities, on how to reach a consensus on how to deal with the mine contamination continuously draining into the Upper Animas basin.
“Right now, we anticipate running (this facility) into the summer,” Way said. “The decision to continue to operate, what happens in the long term – that will be made over the course of the winter.”
Joe Harrington, vice president of Alexico, said his company designed the treatment plant to last longer and be expanded upon, should a Superfund ultimately be enacted.
“Temporary is not our word,” Harrington said. “Interim is a better word.”
The facility cost about $1.5 million – lower than the estimated $1.78 million the EPA projected – and runs about $16,000 a week to operate. That money will come out of a fund related to the Superfund program.
Harrington said the system is designed to endure the area’s harsh winter weather. An average of two staff members will monitor the site through that time, and each will be issued with the proper equipment to notify downstream communities in case of an emergency.
