While the extractive industry has the potential to significantly impact ecological systems, at Gem Diamonds, we take our duty of care seriously – seeking to minimise, manage and mitigate potential environmental impacts at every stage of the mining lifecycle.


  • Increasing community benefit


  • Zero major environmental incidents for the tenth consecutive year.

  • Zero significant environmental incidents for the fifth consecutive year.

  • US$0.6 million invested in environmental protection during 2018 (2017: US$4.8 million).

  • No fines for environmental transgressions or non-compliance with host country legislation for the ninth consecutive year.

  • US$17.9 million environmental rehabilitation provision (2017: US$17.3 million).

Related UN SDGs

Our challenges

  • Managing water quality and consumption challenges across the Group.
  • The remote locations of our mines combined with limited formal waste-disposal facilities within our host countries have challenged us to rethink the way we approach waste management.

Our future

Going forward, we remain committed to ensuring best practice environmental management across the Group, with a particular focus on water and waste management.

Material matters

Water supply and quality

Our context

Across the globe, there is a growing gap between water supply and demand. As a responsible corporate citizen we are duty-bound to act with consideration concerning freshwater resources. Effective water management is crucial for the viability of our business – this refers not only to the preservation of natural resources for the benefit of host communities but also to the cost implications of water consumption on our business.

The tributaries of the Khubelu River and one of the tributaries of the Matsoku River drain into the Letšeng Diamond Mine lease area. Both these rivers flow into the Senqu River, which feeds into the Lesotho Highlands Water Scheme. Safeguarding the quality of water entering the tributaries is of the highest priority for both the future of the operation and for the communities that rely on a stable supply of water.

Our approach

By understanding our total water footprint, we are able to develop an integrated understanding of our water use. We monitor the total volume of water withdrawn by source to ensure we appreciate the scale of potential risks and impacts. Our recently developed water balance focuses on addressing concerns surrounding ground and surface water resources and is updated regularly to inform water management decisions.

The surface water monitoring programme at Letšeng currently indicates an upward trend of nitrates in the process water. Following investigations, we concluded that this increase is the result of the emulsion-based explosive (ammonium nitrate) generating a residue during incomplete combustion in the blasting process. Our efforts to minimise the potential nitrate contamination at Letšeng include using revised blasting practices and materials.

The Patiseng TSF and the Qaqa waste rock dump are currently experiencing seepage into the Patiseng and Qaqa River systems, with an upward trend of nitrates noted in the effluent. In the Patiseng tributary, a return water system has been constructed to capture the seepage from Patiseng TSF. At Qaqa, we constructed a wetland that filters nitrates from seepage flowing from the waste rock dump.

We conduct regular monitoring of the water quality in the Patiseng, Qaqa, RTZ and Mokoalibane water catchment systems. During the year, it was noted that water leaving the mining lease area in the Patiseng, Qaqa and RTZ valleys exceeded the legal guidelines. However, it was established that once the water reached the major watercourses of the Matsoku and Khubelu rivers, the levels of nitrate reduced significantly to the guideline concentrations. To ensure the health and safety of our communities, all villages at risk of consuming water with elevated levels of nitrate have been provided with potable water.

We continue to address the potential contamination through a variety of initiatives, including our bioremediation initiative (see case study). Furthermore, Letšeng has developed an integrated water-management plan to protect groundwater and surface water resources.

Regular water quality monitoring is ongoing at Ghaghoo, despite the mine having been placed on care and maintenance.

Our performance

  • Total water footprint was 8 383 339 m3, and water sources include municipal supplies, groundwater, surface water and direct rainfall (2017: 8 496 384 m3).
  • Total water footprint, in relation to carats mined and tonnes of ore treated, was 37.6 m3 (2017: 42.9 m3 ) per carat and 1.28 m3 per tonne treated ore (2017: 1.31 m3 per tonne treated ore).
  • Total water recycled and reused was 4 367 517 m3 (2017: 3 161 598 m3).
  • Upscaling feasibility studies for our bioremediation project commenced during 2018, the next steps for the project to be decided upon completion of these studies in 2019.

Our context

We recognise the critical need to decouple economic activity from greenhouse gas (GHG) emissions to protect global climate stability going forward.

In addition, we understand that responsible waste management also has a significant role to play – not only in the sustainability of our business but in the long-term viability of our planet.

Our approach

We monitor and measure our carbon footprint in order to develop and implement initiatives to mitigate our impact. We also track the tonnes of CO2 emitted per employee and per carat recovered to consider our impact in isolation from the size of our operations.

Managing waste remains a priority. The proper disposal of waste is an ongoing challenge that we take seriously. In addition to making every effort to reduce waste, we ensure compliance with host country requirements to minimise our impact on the natural environment and surrounding communities. Both operations have waste-management plans in place to ensure that effective waste-handling mechanisms are enforced.

Ghaghoo continued to run its waste-separation-at-source initiative and assisted the Lephephe community with waste management where possible. Mineral waste at Letšeng is retained on-site in structures designed for this purpose. These structures are operated in compliance with the host country’s requirements, as well as international best-practice standards. Waste generated by our non-mining operations remains limited to small quantities of domestic waste.

Our performance

  • Total carbon footprint for the Group was 161 491 tCO2 (2017: 155 106 tCO2e).
  • During 2018, the tCO2e per carat was 1.27 (2017: 1.29).
  • The ratio of tCO2e per employee in 2018 was 73.7 (2017: 74.2 tCO2e).
  • Waste management campaigns continued at both operations.

Our context

Nestled high in the Maluti mountains, our Letšeng mine is often host to blizzards, extreme cold and snow while our Ghaghoo mine, situated in the Central Kalahari Game Reserve, experiences extreme year-round heat.

Given these challenging locations, we need to adapt our methods of operating to remain resilient and to ensure that the effects of extreme weather or natural events do not pose unnecessary risks to our people or the environment.

Our approach

To prepare for these extreme conditions, we have implemented a number of protocols. In addition, given the unpredictability of the environment, reactionary measures are considered and regularly assessed.

Moreover, we take into account the potential risks that climate change poses to our operations such as flooding or drought, which could disturb mining, transport to and from our operations, as well as our rehabilitation efforts. Fluctuations in temperature associated with climate change could have severe repercussions in operating conditions that already oscillate between extremes. Food security and the prevalence of disease are further impacts of climate change that need to be considered.

As part of our business-continuity plan at Letšeng, we have installed generators to assist during energy interruptions and keep a two-week supply of diesel for the generators on the mine. A two-week supply of food is also maintained. Our medical teams have been equipped to deal with extreme weather conditions and have had extensive training in high-altitude rescues and providing medical treatment under extreme conditions.

Our water management systems must also consider potential natural events. At both mines, dam and storage facilities are managed in such a way that there is excess capacity to handle a sudden influx of water without compromising the safety of the structures. We have also instituted water-saving campaigns at both mines to preserve water and ensure it is treated as a precious resource at all times.

Our performance

  • No extreme weather or natural events were recorded during 2018.

Our context

Energy is essential to life. However, current global energy usage trends – particularly the use of environmentally inefficient fossil fuels – are not sustainable.

Our approach

Tracking our consumption patterns enables us to identify opportunities to improve our energy efficiency in areas that make the most significant impact. To ensure the accurate and efficient monitoring of energy usage, we have appointed a facilities manager to oversee the energy management of our operations.

Letšeng implemented an ISO 50001 Energy Management System. ISO 50001 provides organisations with a structured framework to manage energy.

At Ghaghoo, energy usage was drastically minimised once the operation was placed under care and maintenance. However, two generators remain in use for essential services.

Our performance

  • 1 172 244 GJ total energy consumed (2017: 1 140 784 GJ).
  • Group-wide energy intensity was recorded as 9.2 per carat (2017: 9.51 GJ).
  • Letšeng saw a 2.5% increase in total energy consumption. The operation reported a 4% increase in grid-supplied electricity consumption.
  • During 2018 the Group recorded a minor increase in energy consumption as a result of ore haul distance increase at Letšeng which resulted in higher diesel consumption as well as several capital projects that resulted in a greater reliance on grid electricity.

Our context

Mining has a finite life span, and we understand that the complete rehabilitation of our mine land will be expected of us in the future. As such, all of our projects' lifecycles are focused on the eventual restoration of the land we use.

Our approach

We pursue best practice in mine-closure planning, going beyond what is required by host-country legislation, as we believe that this forms part of our responsibility to our host countries and to the communities that live in proximity to our mines.

Our operations have integrated rehabilitation plans in place to ensure that we meet our closure objectives as efficiently as possible. With these plans, we can better manage the environmental impact of our operations, as well as identify cost-effective rehabilitation strategies. Plans are revisited on an annual basis, and in 2018 we made further progress in integrating progressive rehabilitation programmes into the Letšeng mine plan.

We undertake an annual quantification of 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 Letšeng to ensure that environmental damage is continuously mitigated.

Our Letšeng mine, located in the extreme highlands of Lesotho, faces a unique challenge in that guidance on successful rehabilitation is scarce. In 2012, we, therefore, began a series of trials to examine different rehabilitation applications to test the closure criteria, which form the basis of the estimation 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 trials utilised waste rock and tailing reserves, allowing for minimal topsoil requirements. The trial also included studies on vegetation rehabilitation and restoration of natural ecosystems. Vegetation restoration studies were conducted within the mining lease area with the aim of researching veld-rehabilitation options. See our case study for more information.

While Ghaghoo is under care and maintenance, its rehabilitation plans continue to be revised, and we continue to investigate restorative initiatives with the aim of reducing the end-of-life-of-mine liability.

Our performance

  • US$17.8 million environmental rehabilitation provision (2017: US$17.3 million).
  • In 2018, 6 174 ha of land were under our management(2017: 6 174 ha). Of this, 159 ha were newly disturbed by mining operations that occurred during the year (2017: 12.45 ha), bringing total disturbed land to 736 ha (2017: 577.45 ha).
  • Rehabilitation plans were updated at both mines, and rehabilitation and revegetation trials at Letšeng are proving successful.