school energy&environment

Rehabilitation of a mine

If the open mine is in a plain, the excavated area can partly be filled with the topsoil that was removed previously and then covered with agricultural humus.  For this reason, when exploiting the resources of a mine, attention must be made not to mix the topsoil that was removed and the waste materials. If instead the clayey bottom of an excavated mine comes in contact with the water table, the excavated area could be used to create a small lake. These basins, that are the residues of the extraction activities, can be allocated to sports fishing activities, hobbies, ichthyculture, irrigation uses, naturalistic oases or  if they are quite large, to sea-sports. Examples of this  are: the Parco della Fornace Carena park in Cambiano (TO) and the Unieco ecologic park, and the Fosdondo furnace  in Correggio Emilia.
If the mine is on a mountain slope, the principal need is to reintegrate the excavated area back  in the surrounding landscape, and at the same time guarantee the stability of the slope where the activities were carried out. Therefore it is necessary to rapidly grow a plant cover which will allow an efficient consolidation of the escarpment, and  will also mitigate the erosive phenomena. Particular attention must also be paid to the possibility of using depleted quarries as landfills for waste. In the case of clays, for example, the mines are dug in not very permeable rocks, whose characteristics can be considered suited to act as “containers” for polluting substances derived from waste treatment. Clays have also been indicated by the EEC as rocks that can solve the problem of eliminating radioactive waste. It can be concluded  that the negative effects related to the extracting activities can be greatly limited if an intervention is carried out preventively, during the planning stages. Lastly it is important to point out that the excavated area, once it has been recovered, is extremely fragile from the point of view of its ecosystem, and therefore it must be controlled constantly.