Planning ahead to mitigate our long-term environmental impacts

Mining is a temporary activity, with the life of a mine lasting anywhere between a few years to a few decades. During the time that a mine is in operation, however, it generates environmental impacts that should be remediated to demonstrate responsible stewardship of natural resources. This remediation is a costly undertaking, and once a mine is no longer generating income, it is difficult, if not impossible, to raise the capital required to carry out this activity.

Planning for mine closure is therefore an essential part of mining responsibly and in most cases is required by law. At Gem Diamonds, we pursue best practice in mine closure planning, going far beyond what is required of us by host country legislation as we believe that this forms part of our responsibility to our host countries and the communities that live in proximity to our mines.

Every year we quantify the rehabilitation and restoration costs should there be a sudden and unforeseen closure of a mine. Adequate financial provision for this is recognised in the Group’s statement of financial position. In addition, concurrent rehabilitation is pursued at both our operations to ensure that environmental damage is continuously mitigated and not left to end of life of mine.

At Letšeng, a series of trials to examine different rehabilitation applications began in 2012. The mine, which is located in the extreme highlands of Lesotho and experiences extreme weather conditions, faces a unique challenge in that guidance on successful rehabilitation is scarce. The trials are therefore necessary to test the closure criteria, which form the basis of the quantification of the mine’s rehabilitation and closure costs. The trials have been selected to replicate the rehabilitation of the mine’s main waste residue disposal facilities, that is fine tailings (slimes), coarse tailings and waste rock.

The location of our Ghaghoo mine is also unique and has required a constant focus on learning and development. During 2015, a detailed update of the mine’s rehabilitation and closure plan was commissioned, as well as the associated costing, which resulted in the Group reassessing our rehabilitation liability. For both operations, the closure plans are constantly reviewed and updated based on research performed at the mines as well as industry best practice.

 
Rehabilitation trials at Letšeng.   Seed propagation project at Letšeng.