Crew to begin mitigation of second underground mine fire near Boulder County

State crews wrapped up the mitigation project on the Lewis Mine Fire in April ahead of schedule, and the Colorado Division of Reclamation, Mining, and Safety (DRMS) is looking to tackle the Marshall Coal mine fire next.

These two sites started garnering a great deal of attention following the devastating Marshall Fire that killed two people in 2021 and burned 1,000 homes and businesses.

Boulder

State nearing completion of underground mine fire mitigation south of Boulder

Rob Harris 9:45 PM, Feb 16, 2024

Officials don't believe these underground mine fire sites contributed to the fire. Instead, the Boulder County sheriff said, it was likely caused by a downed Xcel power line and embers from an earlier fire buried on private property.

Since the historic Marshall Fire, monitoring at the site hasn't shown any changes in temperature or surface expression.

That's why the mitigation project at the Lewis Mine Fire took place first. DRMS crews said there was increased mine fire activity, surface fracturing and cracking and higher surface temperatures.

Boulder

State nearing completion of underground mine fire mitigation south of Boulder

Rob Harris 9:45 PM, Feb 16, 2024

Efforts at the Lewis Mine Fire didn't impact Boulder County or the city's open space, but they could affect the area near the Marshall Mesa Trailhead.

Denver7 is working to confirm when the mitigation project on the Marshall Coal mine fire will begin. We know leaders previously reported it would start sometime this year.

Mitigation efforts involve crews digging about 30 feet underground, just below the coal mind, and removing any burning or smoldering coal, according to Boulder County . The coal is then be blended with rock or soil and monitored until it is less than 100 degrees Fahrenheit. DRMS monitors the site during this process to make sure the surrounding area stays safe, and will not dig on days with high wind.

Officials know of at least 38 total coal mine fires burning in Colorado, including the Lewis Mine Fire and Marshall Coal mine fire, according to the Colorado Underground Coal Mines Fire 2018 State Inventory Report.

More than 250 were reported nationwide as of September 2021.

These underground fires can burn for decades, according to Smithsonian Magazine . They start when coal is exposed to oxygen, creating a chemical reaction that produces heat. That process can build for years, and the danger is that they can spontaneously combust.

Crew to begin mitigation of second underground mine fire near Boulder County

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