Twentymile is a longwall operation. Remotely controlled, the shearer removes 40 inches of coal from the face during each mining pass. Longwall panels at Twentymile are 1,000-feet wide and extend up to three miles long. A 50-foot section of the panel is removed each day.

Twentymile’s innovative conveyor belt technology is known industrywide. Twentymile was the first to develop a scissorveyor that allows flexibility of the belt structure and eliminates production delays for structure removal as the longwall retreats. Twentymile maintains more than eight miles of underground belt line. A 72-inch wide panel belt and high-speed 60-inch mainline belt have the capacity to move more than 12 million tons of coal a year to the surface.

It is assumed that access to the coal reserves in the LBA tract would most easily be achieved from the existing underground workings at the Foidel Creek Mine with existing surface facilities. The BLM assumes that the coal identified in the LBA—the Wolf Creek seam—would be recovered using the longwall method of underground coal mining. Mains and longwall panel gateroads would be developed using continuous miner units. A continuous miner unit would consist of a continuous miner, shuttle cars, roof bolter, belt feeder, and conveyor belts. A longwall system would be used to mine the coal in the longwall panels. A longwall system includes a shearer, face conveyor, and shields. As the coal is sheared from the face, the face conveyor transports the coal to a crusher which dumps the crushed coal on a conveyor belt. Additional conveyor belts transport the coal to the surface.

Twentymile Coal, LLC uses a coal preparation plant at the Foidel Creek Mine to remove rock, and other impurities from run-of-mine (ROM) coal through washing and separation processes to meet customer’s specifications.

Sources of direct emissions at the Foidel Creek Mine include the following: Point sources such as material handling, transfer, crushing, screening, and loading, propane vent shaft heaters, mine ventilation, and internal combustion engines;