DRMS successfully extinguished the Corley mine refuse pile. (Photo: DRMS)
The Colorado Division of Reclamation, Mining and Safety (DRMS) recently announced the successful extinguishment of the Corley mine coal refuse pile, which had been burning for two decades, completing all phases of the Corley Mine Surface Burn Mitigation Project.
The fire, which was originally ignited by spontaneous combustion, was an accumulation of coal waste, carbonaceous shale and coal ash totaling approximately 82,000 cubic yards. The pile was built up in the 1950s when the mine operated, and began burning nearly twenty years ago.
Temperatures within the pile ranged from 120°F to 200°F, with occasional pockets of hotter temperatures, but in Spring 2025, DRMS reported consistent temperatures above 300°F. A 9.5-acre project area was established to create a fire barrier around the 1.5-acre burning refuse pile, and DRMS launched the Corley Mine Surface Burn Mitigation Project.
Phase 1 focused on extinguishing the fire through excavation, quenching and blending. The coal refuse was excavated and quenched with water at a rate of five gallons per cubic yard. The material was then blended 1:1 with an additional 82,000 cubic yards of non-carbonaceous material sourced from onsite stockpiles. After blending, the material was allowed to cool below 90°F before being backfilled. In total, excavation and backfill operations addressed approximately 164,800 cubic yards of material across the 9.5-acre site. Phase 1 was completed in November 2025.
Following fire suppression, Phase 2 focused on final reclamation of the site using a Geomorphic Natural Regrade Design. Approximately 30,000 cubic yards were moved to improve drainage, reduce erosion and integrate the site with the surrounding landscape. Revegetation efforts were also completed using native seed mixes to support ecological recovery and long-term site stability.
Source: www.coalage.com
