The Slagle/Bright Diamond coal mine northeast of Ridgway, Colorado (map) has been burning since the mine was abandoned in the 1930s. In 1954 an eight-foot thick earthen cap was spread over it in an attempt to suffocate it, and until recently there was little evidence that it was still burning. Now vents have opened, air has gotten into the mine, and smoke is coming out of some of the vents.
The Slagle/Bright Diamond mine is one of 34 active coal mine fires in Colorado. We have written before about coal fires (7 articles), and specifically about fires in Colorado and Montana. Montana recently began putting out nine coal mine fires.
The Watch has an interesting article written by Peter Shelton about the effort by the Inactive Mines Program of the Colorado Division of Reclamation, Mining and Safety to suppress these fires. Here is an excerpt from the article, in which Steve Renner from that agency is leading a group of heavy equipment contractors in a site visit prior to awarding a contract for capping the burning Slagle/Bright Diamond mine.
“This one looks underwhelming when you’re standing around kicking the dirt,” Renner said of the unassuming, 1.5-acre site. “But those big circular collapses? Those subsidences where the earth has caved in can provide oxygen to a fire. And then they can get very, very hot. Which leads to more hollowing out, more collapsing.”
And then you have a public health and safety issue. “Someone could fall through into the fire. Or it could start a wildfire,” he told me later. “And the hazard there is just infinite: in terms of dollars, firefighters, watershed damage, etc.”
Renner is Project Manager for the Inactive Mines Program of the Colorado Division of Reclamation, Mining and Safety. He’s a geologist by training. “But mine fires are kind of my specialty.”
There are 34 active coal mine fires in Colorado, he said on the drive up County Road 4. Most are within an hour or two of his office in Grand Junction. Many more have been capped and have stopped burning. Or gone dormant. The Slagle was given an eight-foot thick earthen cap in 1954, in an effort to suffocate it. But now it was back, the vents opening up, the fire breathing with new life.
The contractors were there for a pre-bid meeting, to research what they thought it would take in equipment and man-hours to suppress the fire. Again.
Renner, who is tall and boyish, with surprising white hair, led the way up, away from the pickups onto the hillside. The only remnants of the mining were a dilapidated “load-out” and off to the side a chinked log cabin with the glass still in its wooden window frames.
The first vents could have been big badger holes. But Christy Hulsman, with the federal Office of Surface Mining, warned me to stay back. “We don’t want a journalist falling through,” she said in a soft Kentucky accent. She’d only recently been transferred out West, to the Denver office, from her home state, where coal mines and mine fires are facts of life. “It’s got that smell,” she said, sniffing, unable to come up with a comparison for the sour stink. “It just smells like coal.”
Renner told the contractors that step one in the suppression job would be to fill the vents with dirt, by hand, “to try to choke them off, rather than just spread material over the top with a dozer.” Step two is to backfill the subsidence and vent features with big machines. Then they’ll need to construct a drainage ditch around the whole site and recontour and revegetate the surface.
How do you know a mine is burning without visiting every one of the hundreds of inactive mines around the state? Renner, of course, knows where all the old workings are. He flies around in a small airplane, in late fall or early spring when the snow cover is thin, and looks for “hot spots.” “Sometimes you see smoke,” said Ridgway’s Jeff Litteral, the project manager for the Slagle job. More often it’s just anomalous bare ground (warm earth) surrounded by white.