MICLA

McGill Research Group Investigating
Canadian Mining in Latin America

Time and duration

The mine reclamation plans begin before production at a mine even begins.The goal of reclamation is to restore the environmental conditions to pre-mining conditions. Most mines use a method of progressive reclamation to reduce the timeline to total land recovery. The length of mine reclamation depends on the size of the project and the laws of the country. Care and maintenance programs may be put in place for mines where the production has halted, but may continue in the future.

The closure process follows these steps: shut-down, decommissioning, remediation/reclamation, and post-closure monitoring programs.

Remediation is the cleanup, reclamation is the physical stabilization of the landscape, restoration is the process of rebuilding the ecosystem, and rehabilitation is the establishment of a self-sustaining ecosystem.

Life after the mine

Mine closure requires a lot of planning and includes detailing the disturbed landscape needing reclamation and creating supporting research programs to mitigate environmental disturbance. The costs of environmental remediation can sometimes be extraordinarily high as well depending on the steps taken during the life of the mine.

Economic recovery is also necessary and should be incorporated into the mine closure plan. The end of a mine project means the loss of many jobs and the subsequent trickle down effect into the surrounding communities.

Environmental legacies

Mining projects create huge amounts of waste and damage land surfaces. There are risks of air and water pollutions from tailings and degraded soils. Especially prevalent in metal mines, soils are unable to support vegetation making it difficult to recover the land. New topsoil is needed to support the vegetation, and only certain types of vegetation can survive in heavily concentrated metal soils. Rhizofiltration is the removal of contaminants from flowing water and is achieved through the selection of particular vegetation.

Preventing pollution is more effective at reducing environmental impacts than attempting to find solutions after the fact. A legacy of environmental degradation follows mines that have not undergone proper closure procedures. Acid rock drainage is one of the most severe environmental legacies from mines, it is caused by the exposure of sulphide minerals are exposed to air and water which pollutes water with acidity and dissolved metals.