Colorado Inactive Mine Reclamation Program
Audio By Carbonatix
The Colorado Division of Reclamation, Mining and Safety‘s Inactive Mine Reclamation Program just won a national award for its work in Las Animas County, where it rehabilitated the abandoned West Sopris Mine near the entrance of Trinidad Lake State Park. It edged out projects from other western states to earn the honor from the Office of Surface Mining Reclamation and Enforcement, presented September 25 at the annual National Association of Abandoned Mine Land Programs conference.
“It’s a big honor to be recognized nationally like this,” says Rachael Nickless, project manager for the West Sopris Coal Refuse Project. “It’s just a really good way to share our work and get the word out there about what we do. … It’s very exciting.”
At the conference, Nickless discussed how the Colorado team transformed what was seven acres of coal refuse into soil that can support vegetation. The project also stabilized the refuse, preventing contaminating sediment from draining into Trinidad Lake.
The work was completed in 2021, eighty years after the mine’s 1940 closing. It had opened in 1887, when no regulations existed regarding where to dispose of the waste from mines; the 180,000 cubic yards of coal waste was left in a natural drainage area. “There was no permitting required and nobody really left to take care of it,” Nickless says. “That’s where our program comes in, to address these historic legacy sites.”
The problem in Trinidad was magnified in the 1970s when the U.S. Army Corps of Engineers built flood-control dams along the Purgatory River, forming what would later become Trinidad Lake State Park. As coal sedimentation drained into the lake over the years, the Corps had to dredge the lake.
To fix the environmental degradation, Nickless and her team installed rock-lined channels to direct runoff and stormwater away from the pile of waste as well as reduce erosion of the waste into the surrounding environment. They also worked to blend the remaining waste – huge black piles previously visible to park patrons – into the natural habitat, using a special technique that rehabilitated the contaminated soil.
“We’re in southern Colorado, and it’s a semi-arid climate,” Nickless says. “There’s not a lot of topsoil. There’s not a lot of vegetation to begin with. There was really nowhere for us to borrow topsoil to cap this material to allow vegetation to grow, and it would be a huge cost to import enough topsoil.”
Rather than take on the cost of bringing in topsoil, scientists helped find a way to change the acidity of the coal waste to allow for vegetation to grow. “We took that recipe that the lab came up with and created this cocktail, if you will, of amendments to add to the coal base,” Nickless explains.
By adding 14,000 pounds of limestone and 70,000 pounds of NuetraLime, a fast-acting soil neutralizer, into the top twelve inches of coal soil, the team made the seven acres of the project viable for growth again. Then they seeded the area with native plants, mainly grass. “We really changed the composition of the coal waste entirely,” Nickless says. “That was a really effective, cost-saving way to do this revegetation instead of bringing in topsoil.”
After the re-seeding, the state worked with the Colorado Youth Corps Association to plant 1,500 saplings in the area, mainly of juniper and ponderosa pine.
The total project cost $980,000. Nickless shared information on the soil transformation technique at the National Association of Abandoned Mine Land Programs conference, in hopes that it could help with similar struggles in other states as well as Colorado.
Messes such as this are a priority for Colorado’s Inactive Mine Reclamation Program, which addresses problems with mines across Colorado, from coal to gold and silver; challenges dealing with environmental degradation rank just below handling safety hazards that could cause injury or death if people fell or wandered into open, abandoned mines.
According to Nickless, Huerfano and Las Animas counties in the southern portion of the state face about 25 challenges similar to those tackled by the West Sopris Coal Refuse Project.
While the project will benefit both the wildlife in the area and visitors to the lake, Nickless says it also shows the state’s commitment to the Las Animas community.
“The less sedimentation, the more water the lake can hold, the more activities the citizens can enjoy on the water,” she says. “We really try to do as much as we can down there with our funding. The eyesore of the coal waste that was left behind, blending that in and getting it back to where it was before the coal mining, is a good impact.”
