US Dept. of the Interior
Office of Surface Mining
Washington, DC 20240
Fires are burning within underground coal seams around the world, sending tons of soot, toxic vapors and greenhouse gases into the atmosphere, polluting ground water and leading to mine subsidence as the coal is consumed. In the United States a fire in an underground coal seam in Colorado sparked a blaze that scorched more than 12,000 acres of forest, destroyed two dozen homes, and threatened the resort town of Glenwood Springs.
Many mine fires are started by people burning trash where the coal seam or an abandoned coal mine is close to the surface. The fire spreads into the remaining coal pillars and tunnels and draws air down from the mine shafts and surface subsidence depressions to keep it burning. Smoke and noxious fumes such as carbon monoxide are released to the atmosphere through tension separations that develop within the ground surface, killing vegetation and creating serious health hazards. As the coal left from the past mining operations burns, the mine void can collapse, damaging building and streets above.
According to the Office of Surface Mining Reclamation and Enforcement (OSM), Abandoned Mine Land Inventory System (AMLIS), in 2005 there were 141 underground mine fires in 11 states (OSMRE.gov, 2005). This is considered to be an underestimate for the actual number of fires nationwide.
Within the OSM Appalachian Regional Office, the Division of Federal Reclamation Program addresses mine fire and coal refuse fire related emergencies within the states of Michigan, Maryland, and Georgia and within the Commonwealths of Kentucky and Pennsylvania. These projects range from burning coal refuse piles that threaten to ignite forest fires to underground mines fires that can burn beneath buildings, roadways and grounds releasing deadly gases and leading to mine subsidence. Abatement methods range from complete excavation and quenching with water (where practicable and affordable) to the use of specialty foaming cements and fire fighting foams that are injected into the fire through boreholes drilled from the ground surface. The intent of the injection is to isolate the fire with a barrier of foaming cement followed by the extinguishment of the fire by using a fire fighting foam. Other techniques that may be used include the use of liquid nitrogen to extinguish the fire by the rapid removal of heat.
Eastern Kentucky Mine Fire. The smoke is coming from underground haulage ways, exposed by surface mining. (source, Geology of Coal Fires: Case Studies from Around the World, The Geological Society of America.
Road Subsidence and venting of mine fire in Centralia, PA source(http://www.myspace.com/centralia_mine_fire)
Centralia warning sign (source: http://forgottenpa.blogspot.com/2007/08/centralia-71407.html)