Surface Mining is the main method used to extract coal reserves found in Alberta. Although not widespread, surface mining involves an intense, local alteration of the landscape, the removal the large quantities of overburden (soil, glacial till bedrock) to expose the hydrocarbon resource buried underneath. When mining operations are completed, they usually leave a series of big open pits that must be reclaimed or filled in.
Surface mining is generally less costly and more flexible than underground mining. This type of mining also recovers a higher percentage of coal in a deposit. This type of mining involves removing the topsoil or surface earth, also called overburden from the area to be mined. This is done with huge draglines that have buckets. The cover soil removed is stockpiled for later use. Sometimes the use of explosives is required to crumble the overburden. Stripping the topsoil reveals the coal seam. The coal seam is then mined using "shovels". These shovels can remove up to 16 cubic meters of coal at one time. That’s a lot of coal!
Generally, extraction technology in non-mountainous areas involves the use of massive draglines in order to remove the overburden and expose the coal seams. Power shovels and trucks are used to haul the coal to a nearby processing facility. These machines are huge! and the tire itself stands taller than a regular truck! Some general environmental pressures include noise levels (machinery, blasting), air quality (coal dust), water quality and stream diversions, soil and vegetation removal. Reclamation of open pit coal mines tends to be more difficult in mountainous areas because of the naturally shallow soil depth and greater variations in topography.
