As a resource-intensive industry, Rössing Uranium’s operations impact on natural resources and the environment. For this reason, the mine evaluates, plans and manages such impacts on an ongoing basis and at all stages of its activities. We continually report on our environmental performance in a transparent manner.
Every year, as part of our continuous improvement focus, we set demanding goals for ourselves for the effcient use of water. We acknowledge the importance of caring for the ecosystems and biodiversity in the areas where we operate.
Likewise, we are aware that sustainable growth requires an effective response to climate change. As a signifcant uranium producer and consumer of energy, we are committed to reduce greenhouse gas (GHG) emissions.
Measurement of performance against our objectives and plans is discussed in the subsequent pages.
Rössing Uranium is conscious of the fact that water is a precious resource; and because the mining industry is typically a large water user, water conservation measures at the mine are taken seriously.
As the mine is located in the Namib Desert, water management is a one of the most crucial environmental and operational focus areas of our activities. Water management includes all aspects of groundwater pumping, seepage management as well as storage, reuse and recycling of surface and groundwater.
Guiding Rössing Uranium's Water management plan is a formal Water strategy which was developed according to Rio Tinto’s performance standards and guidelines. The aim of the plan is to ensure effcient, safe and sustainable use and protection of water resources and ecosystems.
A cornerstone of the mine’s water and seepage management is our comprehensive monitoring programme, which begins at the Tailings storage facility, extending to the Khan River and Swakop River.
Since 1980, we have been recycling 60 to 70 per cent of our water which is indicative of an effective water management strategy.
Water management at Rössing Uranium includes all aspects of groundwater pumping, seepage management, as well as storage, reuse and recycling of surface and groundwater. One of the water-monitoring points in the Panner Gorge in the mine's licence area is tested by geohydrologist, Stefaans Gaeseb, and operator, Water Management, Jeremy Keister.
Most of the mine's water management takes place at the Tailings storage facility where water from the facility is captured in storage ponds and returned to the Processing plant.
To best manage and optimise our water savings we use frequent ﬂow-meter readings taken at various points in the Processing plant to provide a continuous overview of our water balance data. All spillages in the Processing plant are captured and channelled to a large recycle sump for reuse. Efﬂuents from the workshops are treated to remove oils, and sewage is treated in the onsite sewage plant. These purifed efﬂuents are used in the Open pit for dust control purposes.
Figure 11 shows an overview of the 2016 water balance, specifcally the recycling of water from the Tailings storage facility to the Processing plant.
Our operating plan of 2016 set a target for freshwater usage of 2.9 million cubic metres (m³) supplied by NamWater. The actual consumption of fresh water came to only 2.1 million m³ in 2016.
As was the case in the previous reporting year, the freshwater use for 2016 was lower than anticipated. This lower consumption in water usage was primarily attributable to lower processed tonnes against the operation plan in the plant, as well as to water-saving efforts that was instituted on the mine, for example the installation of mechanical seals which reduces the use of fresh water in slurry pumps.
The bars in Figure 12 show that the actual monthly freshwater used was lower than planned during most months in 2016. This relates to the line graph in Figure 12 which shows the water consumption rate for one tonne of ore milled.
For that rate an annual target of a maximum of 0.30 m³ per tonne ore milled was set for 2016. For most of the months this target was achieved.
Another measure of effciency is the volume of fresh water consumed per tonne of uranium oxide produced. Performance between 1983 and 2016 is indicated in Figure 13. The increase in freshwaterusage rate per fnal product produced in the last few years is explained by lower ore grade, which requires more ore to be milled to achieve the same uranium oxide production output.
Demand management of fresh water remains a key challenge for us, with issues relating to periodic interruptions in supply from the bulk water supplier, interruptions in the functioning of pumping systems, unavailability of spares parts, and a lack of adequate storage capacity for the water recycled.
In view of these factors, various campaigns were launched to heighten awareness among employees and contractors concerning the reduction of demand and responsible consumption throughout the year.
During the reporting year we continued our internal ‘Water Bucket’-awareness campaign published in our in-house newsletter, the e-Rössing Bulletin, to ﬂag critical issues for all water users.
In June 2016, the environmental clearance certifcate for the construction of Rössing Uranium’s own desalination plant at Mile 4 close to Swakopmund, was received from the Environmental Commissioner’s offce of the Ministry of Environment and Tourism.
To meet prerequisites for receipt of the certifcate, Rössing Uranium applied for the water permits required by the Directorate Water Resources Management of the Ministry of Agriculture, Water and Forestry in September 2016. No reply from the directorate had been received by the end of 2016.
The current cost of water is high and the mine remains open to implementing alternative measures to reduce the cost of desalinated water.
Khan River water use
Rössing Uranium resumed its abstraction of saline groundwater from the Khan aquifer following the encouraging rainy season of 2011. The groundwater is sprayed on the haul roads in the Open pit to suppress dust.
Such abstraction continued under the permit issued by the Directorate Water Resources Management. The mine will apply for an extension of the permit early in 2017.
A total of 134,265 m3 of Khan River water was abstracted during 2016, which is 15 per cent of the permitted abstraction of 870,000 m3 per year.
We continue to monitor the vegetation and water levels in the Khan River to prevent over-abstraction.
In compliance with conditions of the abstraction permit, annual reports derived from the water and vegetation monitoring programme are sent to the Ministry of Agriculture, Water and Forestry’s Directorate Water Resources Management.
The map shows the approximate position of the seepage plume around the Tailings storage facility and the location of water sampling points.
Water quality management programme review
Towards the end of 2015 Rössing Uranium embarked on a project to improve the mine’s water quality management programme which includes the water monitoring aspects, as well as seepage water recovery.
The aim of the project is to maintain an effective seepage recovery system for the future. The seepage recovery system prevents tailings solution to ﬂow towards the Khan River. The map above shows the approximate position of the seepage plume around the Tailings storage facility in 2016, nearly 5 km to the northwest of the Khan River.
The project comprises of two phases (phase 1 - study phase; phase 2- implementation phase), with phase 1 successfully completed in 2016 and phase 2 to be executed in 2017.
Waste management: reduce, reuse and recycle
Mining operations are resource-intensive, consuming land, water, power, fuel, chemicals and construction materials in order to extract the metal held by the ore body.
During the ore mining and metalrefning processes, waste materials are produced which consist of mineral wastes, in the form of rock and process tailings, and other waste products generated by the services that support the mining process.
Non-mineral waste materials include, for example, waste water, scrap materials, used oils and lubricants from maintenance activities, as well as substantial amounts of packaging materials such as containers and wooden pallets. The aim throughout the various processes is to reduce the generation of waste materials and liquids, reuse these whenever possible and recycle them when reuse is not possible.
The mineral waste generated during operations in 2016 amounted to 25.7 million tonnes, including 9.2 million tonnes of tailings and 16.5 million tonnes of waste rock.
Tailings were deposited on the existing Tailings storage facility, mainly in the re-activated deposition areas that were prepared in 2015. The tailings footprint extended by 4.65 ha, or 0.6 per cent, into a partially disturbed area immediately north of the facility. A plant rescue operation preceded deposition. (See the case study at bottom of this page.)
Rock waste was deposited on the existing rock dumps close to the Open pit with no extension of the footprint. The total mineral waste inventory generated by Rössing Uranium over the past 40 years now consists of 1.36 billion tonnes, covering a total footprint of 1,377 ha, which is about the same size as the town of Swakopmund.
In June 2016, a new waste management contractor was appointed by the mine. The contractor handles recyclable materials such as scrap metal and packaging materials, including containers, paper and wooden pallets.
Waste sorting has been introduced on site, resulting in a shift in distribution of waste streams towards higher volumes of recyclable materials and minimal volumes of various waste materials for disposal.
Waste is sorted by the waste management contractor in Swakopmund and send to Windhoek for recycling. This has facilitated the closing of our landfll site which had been in operation for 40 years. An oil-recycling company purchases the mine’s waste oil for recycling.
Radioactively contaminated wastes are co-disposed on the Tailings storage facility. Other hazardous nonradioactive wastes are disposed of at the hazardous waste facility of the Municipality of Walvis Bay.
Air-quality management in mining is a complex task, primarily because dust types are so diverse. Most are diffused and highly variable in nature and therefore diffcult to measure. Dust sources are site-specifc in terms of silt and moisture content.
Our mining and milling activities release emissions into the air. Dust is generated during blasting, loading and tipping of ore and waste, as well as during crushing and conveying ore.
Winds at speeds above 30 km/h potentially erode fne particles from rock dumps and the Tailings storage facility and disperse them in the environment.
In addition, noise and ground vibrations are created during blasting which is conducted about once a week, while the machinery deployed in the Open pit and the Processing plant generates noise continuously.
Dust emissions are of concern to residents of Arandis and Swakopmund, especially when high velocity winds occur in the winter months. Activities such as mining, crushing and driving of heavy vehicles on unpaved roads are the principal producers of dust. In order to quantify volumes of dust, a monitoring network is in place. Appropriate standards are used to assess monitoring results to establish whether dust levels should cause concern.
Two types of dust are measured: frstly, a very fne dust invisible to the naked eye (known as PM10) and secondly, fallout dust, which is visible on the ground and can be measured as ‘total particulate matter’.
The measure of PM 10 is the weight of particles less than or equal to ten micrometres in diameter in one cubic metre of air. When inhaled, these tiny particles are not fltered out by the body and therefore reach the lungs.
We monitor PM 10 dust levels at four stations continuously. One station is in Arandis, one at the western mine boundary, and two are to the east and west of the Tailings storage facility (see map on the next page, denoted by pink triangles).
The levels measured in 2016 showed that dust concentrations at all stations were below the adopted World Health Organisation standard of 0.075 mg/m3, as indicated in Figure 14 and therefore does not generate concern.
Total dust fall-out is measured as the weight of dust deposited on one square metre of ground in a single day. For this measurement, the residential dust fallout limit published in South Africa in the National Dust Control Regulations (NDCR) on 1 November 2013 is relevant.
The fall-out limit is 600 mg/m2 per day with an annual average target of 300 mg/m2 per day. Fall-out is measured at six stations throughout the year at different locations along the mine boundary (see the single yellow dots away from the Tailings storage facility on the map above).
Values measured during 2016 at the six stations ranged between 4 and 49 mg/m2 per day with an annual average of 18 mg/m2 per day (see Figure 15) and therefore do not generate concern.
The map indicates the PM 10 dust monitoring network samplers and dust fall-out buckets.
Energy efficiency and greenhouse gas emissions
Rio Tinto regards efforts to stabilise global atmospheric concentrations of greenhouse gases (GHGs) at low levels a priority. Correspondingly, we measure and manage energy intensity and emissions.
Sources of GHG emissions at Rössing Uranium include electricity and fuel consumption, the transportation of reagents and uranium, blasting explosives, waste management areas (the sewage plant and landfll site), and the extraction and processing of ore. The intensity of emissions is reported per unit of uranium oxide produced.
In 2016, the total energy consumption of the mine was 1,258,475.98 GJ. This converts to an annual energy consumption of 680 GJ per tonne (GJ/t) of uranium oxide produced, which is above the projection of 438 GJ per tonne.
However, this fgure represents a lower energy consumption when compared with the rate of the previous year when the consumption was 714 GJ/t of uranium oxide produced (see Figure 16).
Emissions of carbon dioxide (CO2) per unit of production in 2016 amounted to 81.81 tonnes of CO 2 equivalent per tonne (CO2- e/t) of uranium oxide, which is below the target of 90 tonnes CO 2-e/t of uranium oxide for the year (see Figure 17).
Current mine plans foresee a cessation of production eight years from now at the end of 2025. Principally, the Open pit will not be backflled with rock; it will
remain a mining void into the future.
By contrast, the Tailings storage facility will be covered with waste rock to prevent dust emissions and rainwater erosion.
Rössing Uranium will continue recovering tailings seepage, but instead of reusing it for mining processes, it will be allowed to evaporate.
The Processing plant and the mine’s infrastructure will be demolished. Recyclable materials will be decontaminated before selling them. Materials not leaving site will be disposed of safely and suffciently covered so that they cannot cause harm.
To achieve these objectives and targets, Rössing Uranium has developed implementation plans for mitigatory measures and calculated the associated closure costs.
The major technical update that had been planned to be conducted in 2016 was not carried out. In lieu of an update, and beginning in 2017, a closure plan at pre-feasibility level, containing more technical detail and higher cost-estimation accuracy, will be developed.
The establishment of the Rössing Environmental Rehabilitation Fund, which provides for expenditures associated with the mine’s closure, complies with statutory obligations and stipulated requirements of both the Ministry of Mines and Energy and the Ministry of Environment and Tourism.
Accordingly, the fund agreement states that each year the mining company will make a contribution to the fund to provide for the eventual closure of the mine.
At the end of December 2016, the fund had a cash balance of N$603 million. In 2016 the total cost of closure, excluding retrenchment costs, was estimated at N$1.5 billion. The mine will make additional payments to the fund each year to provide for the eventual total cost of closure by 2025.
Rössing Uranium continues to fulfl its commitment to responsible environmental management by enhancing biodiversity protection. The lifting and replanting of plant species that are in danger of being disturbed due to our mining activities has been ongoing since the early 1970s.
In the 1970s Rössing Uranium successfully translocated plants that were important from a conservationist standpoint, mainly quiver trees (Aloe dichotoma), from the site of the proposed open pit to the National Botanical Garden of Namibia in Windhoek.
In 2013, with assistance from the National Botanical Research Institute, elephant’s foot (Adenia pechuelii) were also lifted and replanted around the Communication management centre area outside the mine.
In 2016, we lifted and relocated a number of Euphorbia species; blue-leaved corkwood (Commiphora glaucescens); rock corkwood (Commiphora saxicola); sandpaper aloe (Aloe asperifolia), and a few other gems, including the elephant’s foot. These plant species were growing in the vicinity of the area earmarked for the Tailings storage facility extension.
In collaboration with the National Botanical Research Institute, the newly-established Namib Botanical Garden in Swakopmund provided assistance to the mine to lift the plants, and was also a recipient of the rescued plants.
The Ministry of Environment and Tourism has approved the Namib Botanical Garden’s role to guide and replant the Namib ﬂora as most desert plants do not survive well in Windhoek. The group has expert knowledge of lifting, cultivating, propagating, conserving and preserving indigenous Namib ﬂoral as stock for future rehabilitation. Beyond providing advisory services, the Namib Botanical Garden’s objectives include promoting public awareness, research and education at their garden, which is located in Swakopmund.
Transplanting trials are a worthwhile undertaking which demonstrate Rössing Uranium’s commitment to biodiversity protection and conservation. The most recent exercise is a great trial for rehabilitation and restoration purposes.
This commitment is an important factor in obtaining and maintaining access to land and resources, which also demonstrates the exercise of corporate social responsibility to all stakeholders. We are acutely aware how our mining projects and operations impact biodiversity and the ecosystem.
Operational disturbances weaken the natural balance of ecosystems and, in the absence of management, could compromise their integrity. Operations could pose environmental risk to species if they are carried out in areas designated for their particular conservation value, ie if species are of limited range, are endemic to a specifc area or are
protected by law.
Rössing Uranium values its reputation as a responsible corporate citizen and conscientiously complies with governmental regulations and requirements regarding the protection of the environment. Our aim is always to minimise our impact on biodiversity. For this reason, any area that is scheduled to undergo ground disturbance, must frst go through the approval request process which involves consulting the environmental section at the mine.
A number of plant species were relocated from the Tailings storage facility (in the middle on the horizon of the photograph) to other areas of the mine site during 2016, demonstrating Rössing Uranium's commitment to biodiversity protection and conservation.