PERCY MINE FIRE EXTINGUISHMENT PROJECT

The 30-year old Percy Mine Fire, a legacy of past mining, underlies approximately fifty acres on the eastern flank of the Uniontown Syncline in Fayette County, Pennsylvania. Mining has occurred in the Uniontown Syncline (coal basin) for over one hundred years.

Developing a fire extinguishment plan required an understanding of the geology, mining history, mine pool configuration and the fire’s potential to spread, if left unabated. The Pittsburgh Coal was extensively mined in the basin with interconnecting mine workings extending from Uniontown on the south to Connellsville on the north. Three mine pools, flooding most of the underground workings, are defined within this basin. The coal in the center of the basin cannot burn in its current submerged condition. The mine pools discharge at low coal outcrop elevations, thus leaving a portion of the mined coal above the mine pools. Along the rim of the basin or outcrop zone, the mine workings rise out of the mine pool and extend to the outcrop where they become susceptible to ignition and subsequent burning. This zone encompasses a perimeter of more than fifty miles of outcropping coal encircling the syncline. The Percy Mine Fire lies within this zone and continues to plague the surrounding communities. The fire has been a threat to the health, safety and welfare of those living near and over the fire and effectively lowers property values in the vicinity of the fire.

The planning to extinguish the Percy Mine Fire using Low Permeability Cementicious Material^® (LPC_TM), a coal combustion product, was conducted in a joint effort with Pennsylvania's Bureau of Abandoned Mine Reclamation, Reliant Energy, GAI Consultants, Inc., and Howard Concrete Pumping, Inc. The LPC_TM will be injected as a modified grout into the mine workings where it will fill the mine and overlying fissures with a self hardening, dimensionally stable, low permeability coal combustion product.

In the fall of 2004, the Percy Mine Fire will undergo aggressive mitigation using LPC_TM grout blend.