Letšeng Diamonds aims to operate an ISO 14001-compliant environmental management system. This is supported by an updated and comprehensive Social and Environmental Impact Assessment (SEIA) and a Social and Environmental Management Plan (SEMP). All of these meet International Finance Corporation Performance Standards and are aligned with the Equator Principles.
The SEMP is supported by several sectoral management plans, such as Biodiversity, Waste and Hazardous Substances, Air Quality, Water Quality, Social and Energy. These in turn are supported by numerous specialist and scientific studies that were commissioned by Letšeng Diamonds.
In addition, Letšeng Diamonds has studied the “Ecosystem Goods and Services” approach that analyses and seeks to maximise the benefits that the natural environment offers or alternatively seeks to minimise the loss of or offset the loss of such benefits.
Letšeng Diamonds’ operations are at 3275 metres above sea level, on the watershed between Khubelu and Matsoku drainages, which flow into the proposed Polihali Dam and the Katse Dam, respectively. It is imperative therefore for Letšeng Diamonds to meet the challenge of ensuring that only clean and unpolluted water leaves the mining area.
A comprehensive water monitoring protocol has been developed and water samples are taken monthly, quarterly and bi-annually from selected sites throughout the mining lease area as well as from control sites in rivers that are unaffected by the mining activities. The Mine’s performance on water quality is reported to the stakeholders as mandated by the Record of Decisions issued by the Department of Environment of the Government of Lesotho.
Water is analysed for a variety of chemicals including Escherichia coli, nitrates, sulphates and metals. In addition, river health is monitored by measuring the biological status of diatoms and SASS5 samples. Lastly, every effort is made to reuse and recycle the process water, still ensuring that sufficient flow is maintained for use by communities downstream.
At times, slightly elevated levels of nitrates are detected in some of the water sampling points. While the exact causes of this are under investigation, an ambitious and experimental project, an artificial wetland on the tributary of the Qaqa stream, has been constructed. In addition to rehabilitating an area previously mined for alluvial diamonds, it is hoped that the new wetland, perhaps the highest man-made wetland in southern Africa, will reduce the level of nitrates in the water through natural biological and chemical filtering in the wetland biomass.
Although diamond treatment is a relatively “clean” process involving no harmful chemical emissions, any mining activity has the potential to generate dust. Dust monitoring is therefore conducted through monthly sampling. Dust buckets situated at strategic points around the mining area are used. No significant threat has been detected as yet.
Letšeng Diamonds’ carbon footprint is assessed annually. In 2014, a strategy that suggests ways of reducing the Mine’s carbon footprint was developed. In order to reduce harmful emissions from earth-moving machinery, a diesel additive is used. Much of the waste is burned in a European Union-approved incinerator that generates minimal harmful emissions.
“One litre of oil pollutes one million litres of water”. Letšeng Diamonds operates on the principle of zero oil contamination to the environment. Hydrocarbon management, therefore, receives high priority. Workshops and diesel depots are all connected to oil separators to ensure minimal contamination of water and soil.
Whenever an accidental oil spill occurs, the contaminated soil is either treated on-site or collected and transported to a specially designed soil treatment and rehabilitation yard. It is then biologically treated for eventual return to the natural environment.
Letšeng Diamonds has designed and costed the post-mining closure and rehabilitation requirements. Concurrent rehabilitation is being undertaken with the implementation of rehabilitation trials to test various methods in order to estimate optimal techniques for soil stability and plant growth at Letšeng’s high altitude. Letšeng Diamonds has also calculated and made provision for the premature and unforeseen closure of the Mine.
Lesotho’s unique afro-alpine flora is worthy of the highest levels of protection. The Mine is situated on the edge of the Maloti Drakensberg Transfrontier Project (MDTP) and the Ukhahlamba Drakensberg World Heritage Site. The topsoil is stripped from all sites that are to be impacted by mining and stored for reuse in rehabilitation operations. Plants are rescued and cared for at the Mine’s nursery. Propagation of genera such as Scirpus is undertaken for later re-planting by members of the local communities.
Letšeng Diamonds has also created a wonderful biodiversity garden, perhaps the highest such garden in southern Africa, where a collection of Lesotho’s amazing variety of high-altitude flora is on display.
Social and Environmental Management Plan (2019-2022)
Letšeng Diamond Mine is situated high in the Maluti Mountains of Lesotho. Letšeng Diamonds (Pty) Ltd holds the mining lease granted in 1999 by the Government of Lesotho.