The Environmental Protection Agency may be able to cross one of its 48 mine sites included in the Superfund around Silverton off its list.
Recently, the Colorado Department of Reclamation, Mining and Safety completed a successful closure of the Ben Franklin Mine, a long inactive mine site in Eureka Gulch.
Kirstin Brown, a reclamation specialist with DRMS, said the vertical opening of the Ben Franklin Mine created a hazard along San Juan County Road 25. More specifically: People were driving into the unstable opening.
To address the safety concern, DRMS got creative.
A few hundred feet away from the entrance of the mine was the historic waste rock pile of the Ben Franklin, where miners dumped worthless rock taken out of the mountain.
Peter Butler, one of the co-founders of the Animas River Stakeholders Group, said the Ben Franklin waste rock pile was listed in the group’s top 30 or so contributors of heavy metals in the upper Animas River basin.
It was estimated the pile loaded about 100 pounds of zinc into the watershed a year, among other heavy metals. Though the loading isn’t as significant as other sites, it did warrant some remediation, Butler said.
When the EPA declared the “Bonita Peak Mining District Superfund” site in fall 2016, the agency included the Ben Franklin waste rock pile.
And so, as DRMS planned to plug the entrance of the Ben Franklin, Brown said an opportunity presented itself: crews could use the waste rock pile to backfill the entrance.
The benefits were twofold, said Jeff Graves, director of DRMS’s Inactive Mine Reclamation Program.
For starters, people can’t get into the Ben Franklin, removing that risk hazard. And now, the waste rock pile, instead of lying out in the open, is consolidated in the mine and isolated from exposure to storm runoff, which sweeps metals away from the dump and into the watershed.
“Our work was to address the safety hazard,” he said. “But if we can make the environment better, we like that.”
DRMS used other material, such as Portland cement and pulverized limestone, to buffer protections. The project was started Aug. 12, Brown said, and was finished last week.
The Ben Franklin Mine has another adit that is discharging mine waste. EPA spokeswoman Katherine Jenkins said the landowner, Ryan Bennett, and his company have agreed to voluntarily conduct Superfund response work on the property.
Under the agreement, Jenkins said Bennett will work to reduce metal contamination in the Eureka Gulch area from the historic operations associated with the Ben Franklin Mine.
“Mr. Bennett and his company will collect data and monitor the work to assess changes in the flow and chemistry,” she said. “The EPA will evaluate this and other data to determine if any additional work is necessary in the future to meet EPA’s established cleanup goals for the (Bonita Peak Mining District).”