Coal Refuse Piles
Coal mining has been a part of Pennsylvania's industrial heritage for over 150 years. In past times, as coal was removed from underground mines, a certain amount of unwanted material accompanied the coal to the surface. Separating the coal from the refuse material was a necessary part of the process, and large piles of refuse material grew as mining operations continued. Because the separation process was far from perfect, coal itself is generally a major constituent of these piles. The piles are known variously as gob piles, slate dumps, boney piles, and culm banks. They have too often become permanent fixtures on the landscape and are responsible for environmental degradation, including the sometimes prolific production of AMD, as well as being hazards and eyesores. They generally don't support the growth of much vegetation and are characterized by their steep, eroded, unstable dark gray banks.
See Project Gob Pile for a study of the waste coal piles in Westmoreland County
Many piles have been commercially reprocessed to harvest the remaining coal from the other waste materials, especially those having high coal (energy) content. While this commercial activity continues, it is being eclipsed by the direct burning of the material at power plants especially constructed for the purpose of utilizing coal refuse. The relatively new technology enabling the removal of millions of tons of coal refuse is called Circulating Fluidized Bed (CFB) Combustion, and is the greatest hope of removing and reclaiming more coal refuse in Pennsylvania than any other method. There are limitations to how much this technology can be used. It will still be decades before coal refuse piles are only a memory.
Be sure to read about CFB Power Plants, used to remove waste coal.
For piles having little commercial value, other reclamation methods may have to be employed. One such is method is to regrade the pile to eliminate steep slopes, the use various water management practices to keep water from infiltrating the pile, and to cap the pile with soils and other amendments to promote the growth of vegetation.
Reclamation of Coal Refuse Disposal Areas - Reclamation Guidelines for Surface-Mined Land in Southwest Virginia