Our context

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 therefore of the highest priority for both the future of the operation and for the communities that rely on a stable supply of water.

Although Lesotho has historically been one of the world's most water-rich countries, and a traditional provider of water to neighbouring South Africa, the country has suffered from a severe drought that intensified in 2019, placing exorbitant pressure on the country's water reserves. The Government of Lesotho declared a national disaster on 30 October 2019 and issued a drought response and resilience plan. Gem Diamonds is alert to ways in which we can play our part in alleviating suffering as a result of the drought, and aware that the conservation of our water resources is more crucial than ever.

Our approach

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 We monitor the total volume of water withdrawn by source to ensure we appreciate the scale of potential risks and impacts.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

Regular monitoring of the surface and ground water quality in the Patiseng, Qaqa, RTZ and Mokoalibane water catchment systems at Letšeng continued in 2019 as part of our nitrate management project.

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 tailings storage facility (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. To mitigate the impact of this, a return water system has been constructed in the Patiseng tributary 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 2018, it was noted that water leaving the mining lease area in the Patiseng, Qaqa and RTZ valleys exceeded the statutory 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 project. To date, research undertaken with regard to the feasibility of bioremediation as means of addressing nitrate levels has been promising. We have now proven the concept and have assessed where the pilot plant should be placed, as well as what water it should treat. During the year, we entered the next phase of research, which includes detailed design and costing.

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 in 2017.

Furthermore, we have made a concerted effort not only to invest in the mitigation of impact, but also in the avoidance of impact. We continue to pursue innovative new methods of liberating diamonds to eliminate power-intensive, water-intensive mechanical processes.

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.

The pit slope design at Letšeng Mine was reviewed in 2019 by the Letšeng Geotechnical team in order to reduce mining waste and improve the profitability of the mine, as the volume of waste mined is a function of the slope design. Furthermore, a stability analysis was conducted by the team to derive optimised slope angles. The mine plan was rerun on steeper slopes, resulting in a 100 million tonne reduction in waste mined, as well as an increase in satellite ore of 6 million tonnes, to end-of-life of the open pit. Both the stability analysis and the pit slope design developed by the team were reviewed and approved by an independent external expert during the year.

We endeavour to reduce our use of infrastructure and utilised resources where appropriate. In 2019, we were able to reduce our Letšeng office footprint in Maseru by 40%, from 6 272m² to 3 756m².

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 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 , as well as occasional flash floods.

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, 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 are being considered. 

As part of our business-continuity plan at Letšeng, we have installed generators to provide power to the mine 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.

Lesotho suffered an extreme drought during the year, impacting communities and the mine. We realise that we need to integrate planning of this nature into our resource-management strategy going forward. We have instituted water-saving campaigns to preserve water and ensure it is treated as a precious resource at all times.

Additionally, the upward trend of nitrates in the process water at Letšeng was also impacted by the water shortage, as reduced water levels resulted in more concentrated levels of nitrates in the water. We continue to pursue our bioremediation initiative to address this concern (see water supply and quality).

Our context

Energy is essential to our mining operations. However, we recognise that 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 in 2017. However, one generator remains in use for essential services , along with a back-up generator, when needed.

Our context

Mining has a finite lifespan, 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 2019 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.

Furthermore, due to the location of our Letšeng mine in the extreme highlands of Lesotho, we are faced with the unique challenge 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.

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