Overburden Removal and Placement

The coal operator puts the blasted rocky material in the base of the pit after coal removal in the area is done. Overburden can include layers with pyrite in them and when these are exposed to air and water, they can generate acid. Combining these layers and burying them with neutral materials inside the pit, avoids acid production by not allowing exposure to oxygen. To make sure that an appropriate rooting material is accessible for cropland capacity, the layers under the soil are put on top of the graded rocky overburden while reclamation is taking place. If there is any toxic overburden that can be seen in the pre-mining inventory it needs to be treated or covered with the correct layer of non-hazardous, noncombustible material.

In order to avoid water pollution, all of the water affected by the mining operation is required to pass through an official residue control formation before it is able to leave the mine site, and needs to be in conformity with all related State and federal water quality laws, as well as water discharge permits issued by the Department of Environmental Management in the state the mining process is occurring in.

Coal companies maintain siltation formations on the site until stable vegetation has been established, and the quality of the water that is going into the pond meets up with the water quality restrictions. Any ponds that have not been approved for retention after mining need to be removed and reclaimed.

It is the responsibility of all mining operators to keep a close eye on the levels of the groundwater and the quality of the job done throughout the mining and reclamation development. The operator will also need to supply a substitute water supply, according to some water laws in certain states, where an accessible water supply from groundwater used as a drinking water source is affected due to contamination, depletion, or interruption because of activities related to surface mining.