5.2.2 Site Rehabilitation

Rehabilitation is intended to restore the site’s natural appearance by creating an ecosystem similar to the one that existed prior to mining activities.

Preissac tailings pond in the Abitibi region.

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Rehabilitation is based on the environmental data provided in the site rehabilitation plan, which is drawn up before the mine is brought into production.

The first step usually involves filling the stripped surfaces and pits. The ground and slopes are then levelled to minimize the impact on the landscape.

In some cases, terraces are even built and covered with vegetation to disguise the visible parts of the site.

Careful! To restore the vegetation, a variety of native species must be planted. The site must not be transformed into a single species plantation.

		Restored waste rock piles.
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The tailings pond takes the longest time to rehabilitate.

Tailings and waste water in the pond are treated to prevent acid drainage problems, that is, acid water leaching into the soil.

Treatment systems increasingly use bacteria and plants that feed on metals to clean the water.

One of the most effective mechanisms consists of filtering runoff waters from mining sites in an engineered wetland, that is, a biological pond where plants and bacteria form a self-sustaining ecosystem.

Canada is a world leader in this field.

		Natural marshes are just like purification plants. A growing number are being created on former mining sites to decontaminate the water and soil.
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