State crews are in the final stages of the mitigation project on the Lewis Mine Fire burning underground southeast of Boulder. The fire, which has been burning for more than 50 years, has received more public attention following the devastating Marshall Fire in late 2021.
Crews for the Colorado Division of Reclamation, Mining, and Safety (DRMS) began excavating the Lewis Mine site January 25, 2024. While they found no active flames during their excavations, they regularly encountered smoldering coal at temperatures up to 650 degrees, underscoring the importance of the mitigation effort. An estimated 10,500 cubic yards of coal, soil, and rock have been excavated through the mitigation process, which entails mixing the smoldering coal with soil and rock until it reaches a temperature of 90 degrees or lower.
“And that cools it down very rapidly,” explained Jeremy Reinke, the DRMS project manager for Lewis Mine. “Typically, we can go from 400-500 degrees out of the ground to below 90 degrees in a matter of five to ten minutes.”