Rössing aims to be the leader in environmental stewardship and to maintain its reputation as a responsible corporate citizen. This aim can be realised by understanding and appreciating our biotic and abiotic natural resources, and using them in a sustainable manner to create a net positive impact.
Silke Rügheimer, Curator of the National Botanical Garden, National Botanical Research Institute of Namibia, taking measurements of an Adenia pechuelii (Elephant's foot), earmarked for relocation.
As a resource-intensive industry, Rössing's operations have the potential to impact on natural resources and the environment. We therefore continuously improve our Environment Management Plan (EMP) to maximise benefits and minimise negative impacts. Key programmes include those on -
- water usage;
- energy efficiency and greenhouse gas emissions;
- air quality control (including the emission of dust, other impurities, noise and vibrations);
- waste management (of both mineral and nonmineral waste);
- chemical substance management; and
- land use management (including biodiversity, rehabilitation and closure).
The report discusses Rössing's performance in 2013 over the next few pages with regard to the various EMP programmes.
Water recycling and reuse is the foundation of the mine's Water Savings Programme. 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 on-site Sewage Plant. These effluents are used in the open pit for dust control purposes.
Most of the mine's water management takes place at the Tailings Storage Facility. Surface water from pools forming at tailings deposition areas is recycled and reused on a continuous basis in the plant, minimising evaporation and infiltration into the tailings pile. Remaining water that has infiltrated is recovered by pumping boreholes and open trenches installed on the facility itself to reduce the volume of underground water within the tailings pile.
Seepage control systems are also employed outside the Tailings Storage Facility. They include a surface seepage collection dam to capture water from the engineered tailings toe drains, cut-off trenches in sand-filled river channels, dewatering boreholes situated on geological faults and fracture systems on the downstream western side of the facility. All systems lower the water table to such an extent that flow towards the Khan River is interrupted. The recovered water is reused in the Processing Plant.
A cornerstone of the mine's water and seepage management is a comprehensive monitoring programme. This starts at the Tailings Storage Facility to ensure sufficient capacity at deposition areas, to ensure low water levels in the tailings pools and to ensure the proper functioning of all seepage control systems. On the reuse side in the plant, frequent flow meter readings are taken at many areas to maintain an overview of the water balance at any time.
To ensure that all systems are functional and zero discharge to the Khan River is maintained, water level measurements are taken on a network of more than 100 monitoring points. A number of these points are also sampled to determine the quality of the groundwater, including the concentration of uranium and other radionuclides. As a condition of the permit issued by the Department of Water Affairs and Forestry, monitoring results are submitted to the Department at regular intervals for review.
In 2013, water recovery from all systems was higher than anticipated in 2012.
Rössing's freshwater pipeline with the acid storage tanks in the background.
The total use of fresh water was 2.914 million m3 for the year under review, compared with an operating plan target of 3.194 million m3.
As in the previous year, the water performance for the 2013 reporting period was worse than anticipated, due to the reduction in total tonnes of ore milled in the plant. Lower tonnages at fixed water usage result in a higher unit consumption, as shown for the years 2011 to 2013 in the graphs below. Although we more than ably met our total consumption target, a number of challenges relating to the sustainable management of fresh water remain. These include the periodic supply interruptions from the bulk water supplier, the functioning of pumping systems, and a lack of adequate storage capacity for water in circulation.
In view of the above, various campaigns were implemented during the year to heighten awareness about reducing demand and using supply sustainably. We therefore continued our internal "Waterbucket" awareness campaign published in the mine's in-house newsletter, the e-Rössing Bulletin, to flag important issues to Rössing water users.
Other activities, such as the reed elimination project, came into effect in an effort to reduce water loss through evapotranspiration by reeds. Unfortunately, we were prompted to look into other water conservation alternatives when promising water reduction test work carried out at the tailings pumping system was unsuccessful.
These other alternatives included the Tailings Dam Dewatering Project and the Tailings Dam Extraction Project, which aim at maximising the recovery of groundwater from the Tailings Storage Facility. Both these projects, which we plan to implement in 2014, will yield much-needed low-quality water. This, in turn, will result in a significant replacement of freshwater consumption in the Processing Plant.
Khan River water use and quality
Rössing resumed its abstraction of saline groundwater from the Khan aquifer in August 2011 to suppress dust in the open pit. Such abstraction will continue until at least June 2014, when our permit expires. We will discuss internally whether or not to apply for renewal of the permit before its expiry date.
The mine allows for a daily abstraction of up to 800m3/ day, which is less than the permitted 2,383m3/day, as well as less than the sustainable yield. We continue to monitor the vegetation and water levels in the Khan and Swakop Rivers to prevent over-abstraction.
Inhalable dust, also referred to as particulate matter (PM), is defined as the size of the fraction of dust that enters the body but is trapped in the nose, throat or upper respiratory tract. The median aerodynamic diameter of this dust is about 10μm and it is often referred to as PM10.
The current Air Quality Management Plan guides the management of environmental dust at the mine.
As noted previously, dust is measured in Particulate Matter (PM) ranging in diameter from 10 to 50 micrometres. Activities such as mining and crushing are the principal emitters of dust at Rössing. PM10 is the measure of particles in the atmosphere with a diameter of less than or equal to a nominal 10 micrometres. Measurements are taken to ensure that exposure levels to dust do not exceed prescribed occupational limits and to ensure that existing and newly introduced controls efficiently detect differences as a result of process changes.
The PM10 monitoring point established at the south-west boundary of the mine in February 2012 was functional until the end of September 2013. Unfortunately, components of this station were stolen; only eight months of data could be recorded.
The station will therefore be re-established elsewhere on the mining licence area in 2014. Despite several East Wind events, dust concentrations recorded at this station remained below the Rio Tinto standard of 0.12mg/m3 throughout January to September 2013, as indicated in the graph below.
The low readings - at an average of 0.012mg/m3 - indicate that PM10 dust dispersal from sources in the operations areas is limited in distance, and does not cross the boundary to the south-west of the mine's licence area.
We also continuously monitor PM10 dust levels at the nearby town of Arandis. Although the monitoring station malfunctioned during June, July and August and resulted in incorrect readings, the data recorded for all the other months showed that dust levels were much lower than the standard of 0.12mg/m3, as indicated in the graph below.
Noise and vibration from blasting
We monitor environmental noise according to procedure and monthly reports to minimise it to threshold levels and to identify events when such levels are exceeded.
The information gleaned is vital for assessing Rössing's compliance with various standards and for addressing concerns about excess noise or vibration. Our Geotechnical Section also utilises the feedback to investigate the impact of blast vibrations on the stability of the pit.
The Rio Tinto Performance Standard guides the management of noise and vibration on the mine, and underlies the mine's overall Environmental Management Plan.
During 2013, air blast levels were consistently below the limit of 134dB.
Rio Tinto regards efforts to stabilise global atmospheric concentrations of greenhouse gases (GHGs) at lower levels as a priority. In keeping with this, Rössing also measures its GHG emissions.
The intensity of emissions is reported per unit of uranium oxide produced. At Rössing, sources of GHG emissions include electricity and fuel consumption, the transporting of reagents and of uranium, blasting (explosives), waste (sewage, rubbish disposal and landfill), and extraction and processing of ore.
In 2013, the total energy consumption of the mine was 1,007,659GJ. This converts to an annual energy consumption of 683.27GJ per tonne of uranium oxide produced, which is 22.68 per cent above the target of 556.95GJ/t.
Emissions of carbon dioxide (CO2) per unit of production in 2013 amounted to 78.04t of CO2 equivalent per tonne (CO2-e/t) of uranium oxide (U3O8), which is 17 per cent above the target of 66.85t CO2-e/t of U3O8 for the year. In December 2013, the emissions intensity amounted to 107.42t CO2-e/t of U3O8, which relates to the low production as a result of the leach tank failure.
Lower production resulted in Rössing's energy consumption and GHG emissions per unit of production to be higher than the targets set.
Going green to reduce our carbon footprint
The pit operations invested in environment-friendly lighting sets, using solar energy captured during daylight to provide sufficient light at dumping areas on backshifts at night. The purchase of two new solarpowered lighting sets allowed for the replacement of the traditionally used diesel-generator-powered sets. The solar-powered units provide a similar amount of energy to their diesel counterparts, but do so renewably.
Slightly more expensive than traditional lighting, the solar-powered sets ultimately represent a saving in diesel running costs, reduced engine maintenance and reduced carbon dioxide emissions.
These positive impacts offset the original purchasing cost over the longer term.
In the absence of a clear legislative framework for waste management in Namibia, Rössing uses international standards such as ISO 14001:2004 as well as the Rio Tinto Environmental Performance Standards for conformance.
Rössing identifies its non-mineral waste and keeps a related inventory and risk register for each work area. An over-arching Non-mineral Waste Management Plan is also in place to ensure there is proper control over such waste. Sound management entails minimising the generation of such waste, and handling, treating and disposing of it safely. The Waste Management Plan addresses all types of non-mineral waste generated at Rössing during its operational phase, but the plan would need to be revised for a decommissioning phase. The plan is reviewed at least once every four years. We set specific waste management targets for each year, and monitor and report on their achievement.
Rössing also makes recycling non-mineral waste part of its green plan. Although 2013 saw less steel being recycled than in 2012, the volumes of recycled wood, cardboard and paper increased significantly. Moreover, the total volume of non-mineral waste recorded for 2013 was significantly less than in previous years. For the reporting year, the target for the measurable reduction of nonmineral waste destined for disposal was 80 per cent, while actual reduction registered at 88 per cent. We appointed a local recycling company to handle and remove recyclable non-mineral waste from the mine site.
Rössing's mineral wastes are waste rock and tailings. The intent of our Mineral Waste Management Plan is to ensure such waste is properly controlled by way of reducing waste generation at source, and ensuring the safe handling and disposal of waste that has been generated.
Our Tailings Storage Facility undergoes an inspection at least once a year. Consultants from SLR Environmental Consulting (Pty) Ltd, SRK and Aquaterra do an annual inspection and make recommendations for improvement. In keeping with Rio Tinto requirements, SLR Environmental Consulting also conducts an inspection of the Tailings Dam as a major waste storage facility.
The combined surface area of the Tailings Storage Facility and waste rock dumps measured 1368.84ha by the end of 2013. This reflects an increase from the previous reporting period, following an expansion of the surface area of the Tailings Storage Facility by 3.97ha, and that of the waste rock dumps by 2.08ha.
A Hazardous Material and Contamination Control Management Plan is also in place at the mine. The plan requires the keeping of an inventory of hazardous substances and accompanying material safety data sheets. Management of these aspects of uranium mining also entails controls to prevent or minimise spillages during the handling of chemical substances, the conducting of routine inspections, monitoring procedures for leaks, integrity testing for the deterioration of storage tanks and pipelines, spill and leakage detection equipment and emergency response plans. These aspects are addressed through regular internal and external audits, inspections and monitoring.
Rössing's SJ Open Pit
A total area of 93ha has been rehabilitated over the years. A progressive rehabilitation programme has been followed since 2010 and came to an end in 2013. Several rehabilitation tasks have now been completed. It is anticipated that the total area of rehabilitated land will increase in future before mine closure, as there is increased focus on the importance of rehabilitation at Rössing.
From the biodiversity knowledge base built up over the three decades of the mine's life, it became clear that Rössing needed a better understanding of the bigger picture in which its mining operations were set, ie the entire landscape, particularly the connections, patterns and processes within it. Fauna and Flora International conducted a Landscape Level Assessment for the Central Namib and the findings made available at the completion of the study in 2012 provided essential input to the Biodiversity Action Plan for Rössing, which was drafted in 2013.
Another aspect of Rössing's biodiversity management takes the form of hosting nature-related events. One such event was Rössing's 13th birdwatching event at the Walvis Bay lagoon in September 2013, hosted in conjunction with the Namibian Coast Conservation and Management (NACOMA) project. A total of 54 learners and 11 teachers representing 11 high schools in Arandis, Swakopmund and Walvis Bay participated in the event. As a token of appreciation, each participating school received a donation of science laboratory equipment.
During 2013, Rössing relocated seven individuals of the very rare and endemic Adenia pechuelii species (Elephant's foot plant), which occurred in an area earmarked for a small expansion of the Tailings Dam. Five of the plants were placed on a similar ridge, where other plants of the same species already grow, near the Communication Management Centre. The other two plants were donated to the National Botanical Research Institute in Windhoek, which assisted Rössing with this undertaking.
Worthy of mention is the repeated spotting of cheetahs around Rössing since 2012. The cheetahs have been seen resting as well as hunting and feeding after a kill, all of which indicate that their presence is not merely occasional.
Rio Tinto also contracted Fauna and Flora International to update Rössing's Biodiversity Action Plan and to identify Rössing's needs in respect of its net positive impact. The updated document will guide the required activities for 2014 and beyond in order to plan for the achievement of a net positive impact by closure.
Net positive impact explained: Net means overall or final. Net income, for example, is one's income after taxes and expenses have subtracted. Net positive impact means that the final impact, after considering the entire positive and negative factors, is positive.
Relocation of seven Elephant's foot plants
Demonstrating Rössing's commitment to biodiversity conservation, seven Adenia pechuelii (Elephant's foot) plants, endemic to the Namib Desert, were relocated in 2013. The plants occurred in an area earmarked for a small expansion of the Tailings Dam. Five were relocated to a ridge adjacent to the Communication Management Centre where other plants of the same species already grow. The other two plants were donated to the National Botanical Research Institute in Windhoek, which assisted the team with the relocation.
As a business, Rössing strives to be informed about evolving discussions and conceptual thinking on climate change and, where possible, attends national seminars and workshops on climate change policy and adaptive capacity. These allow Rössing to learn from best practice.
Mine closure is an integral part of Rössing's mine planning cycle, from exploration via mine development and production, to decommissioning and aftercare. Thus, closure planning has been a continuous process at Rössing, and we take into account changes in operational circumstances, environmental conditions, legislative and regulatory frameworks, and stakeholder expectations, as we have done for the each plan update over the past 20 years.
Current Life-of-Mine Plans foresee cessation of mining in 2024 and of processing in 2025.
An aspirational vision for a post-closure situation that is translated into objectives and targets guides Rössing's closure plans. The vision considers mitigating the socioeconomic impact closure would have on our employees, on neighbouring towns in the Erongo Region and on the environment around the mine site.
Principally, we will not backfill the open pit with rock: it will remain a mining void in the future. On the other hand, we will cover the Tailings Storage Facility with waste rock to prevent dust emissions and stormwater erosion. We will continue pumping tailings seepage, but instead of reusing it for mining processes, it will be allowed to evaporate.
Rössing will also break down the Processing Plant and the mine's infrastructure, and decontaminate it before selling it or disposing of it safely.
To achieve objectives and targets, we have developed implementation plans for mitigatory measures and calculated the necessary closure costs. A major technical update of the plan takes place every five years, whereas we update closure cost calculations annually.
The next full technical update will take place in 2016. Five-year plans and annual updates provide the company with a fully scoped and accurate cost of closure that is documented and auditable.
The establishment of the Rössing Environmental Rehabilitation Fund, which provides for the mine's closure expenditure, complies with the statutory obligations and stipulated requirements of both the Ministry of Mines and Energy and the Ministry of Environment and Tourism.
Thus, clause 15.2 states that "The mining company shall before the end of its financial year concerned, pay to the Fund a contribution towards the estimated cost of implementing the measures so approved."
The agreement also stipulates the formula for calculating annual contributions to the Fund. At the end of December 2013, the Rössing Environmental Rehabilitation Fund had a cash balance of N$333 million. The mine will make additional payments into the Fund each year to provide for the eventual total cost of closure by 2025.
Rössing took a decision in 2012 to integrate closure planning activities into business operations, and to provide frequent feedback on progress. To drive and coordinate the various follow-up and scheduled activities, the Closure Steering Committee established in 2012 was re-established after we had completed a company restructuring in mid-2013.
Sequence of photos showing a paddy prior to rehabilitation, and in its rehabilitated state.
Sequence of photos showing a SX fire trench prior to disturbance, during the rehabilitation process, and in its rehabilitated state.
Since the mid-2000s, in our search for new uranium ore, we have drilled a number of areas on the mining lease. As the exploration activities move to new areas, we rehabilitate the explored areas. Because exploration is ongoing, so is the rehabilitation of any disturbed area. During the Z20 exploration drilling programme, for example, a minimal area of 4.3ha was disturbed. We have financially provided for the area's complete rehabilitation in our 2014 budget, should the deposit not be developed further in the foreseeable future.
Over the years, 93ha has been rehabilitated. The most recent exercise occurred between 2010 and 2013, when we conducted a progressive rehabilitation programme that entailed several activities. These included demolishing redundant infrastructure and facilities, remediation, establishing geotechnical stability and protection against erosion. It is anticipated that the total area of rehabilitated land will increase in future before mine closure, as there is increased focus on the importance of rehabilitation at Rössing.
Guidance from legislative and regulatory frameworks on rehabilitation in Namibia is limited. Rehabilitation occurs over the long term and is closely coupled to long-term monitoring requirements and research, especially in arid environments such as Rössing's. The sustainability of rehabilitation interventions is uncertain and clear criteria and sign-off are essential. The existence of exit plans and criteria with regard to relinquishment of land are also important prerequisites for Rössing.
The Z20 Social and Environmental Impact Assessment
The Z20 uranium occurrence that was initially discovered in the 1970s is situated on a portion of Rössing's mining licence area that overlaps the Namib-Naukluft Park to the south of the Khan River. The area adjoins the Husab and Zhonghe Resources mining licence areas to the south and north, respectively. Rio Tinto Exploration has investigated the potential of the Z20 uranium ore body on behalf of Rössing since 2010. In the last three years, Z20 has turned out to be a significant uranium resource situated on Rössing's lease.
We carried out exploration in three phases of drilling, the third phase of which was completed in April 2013. The purpose of this third exploration phase was to define the ore body by drilling a close 50m x 50m grid. This allowed increasing the definition of the resource to Indicated, using the classification system of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the so-called JORC Code). Declaration of an indicated resource also requires the formulation of initial mining plans and the conducting of an initial environmental impact assessment.
Accordingly, the Social and Environmental Impact Assessment of the preliminary mining plans commenced in late 2012. Two components of the plans required assessment. The first of these components covered an infrastructure corridor to link the Z20 area on the southern side of the Khan River to the Rössing Processing Plant on the north by road and overland conveyor. The corridor would be used to convey the ore across the Khan River to the existing Rössing mine's Processing Plant, and to transport people and materials to the Z20 open pit to carry out mining operations.
Rössing's consultants completed the assessment and submitted it to the Environmental Commissioner at the Ministry of Environment and Tourism for a decision at the end of 2012. In July 2013, the Commissioner granted Rössing an environmental clearance certificate to establish the corridor with the condition not to pollute the Khan River.
The second component of the mining plans that required assessment entailed the need to address the mining and rock waste disposal part of the potential Z20 mine. The first half of 2013 saw a number of specialist studies aimed at -
- assessing the likely changes in radioactivity due to mining;
- the effect rainwater infiltrating the rock dumps could have on groundwater;
- the sensitive biodiversity in the desert environment;
- the anticipated change in noise and dust exposure in the proximity; and
- the inevitable change in landscape character due to rock waste disposal.
Although the specialists have assessed the predicted changes, we have not yet carried out an integrated impact assessment for comment or submission.
The price drop for uranium after the Fukushima incident obliged us to postpone our decision to start investing in the new Z20 open pit. It also turns out that the Z20 ore body extends beyond the boundaries of Rössing's mine licence area, and that we would have to move rock dumps away from the sides of the Khan valley onto the bordering plains. Other mining companies hold the more environmentally favourable licence areas. We have therefore established initial contact with neighbouring companies to discuss possible cooperation in developing the Z20 resource.
Rössing made public in November 2013 its decision not to proceed to the final impact assessment, given that we are continuing to work on the arrangements for possible mining of the Z20 ore body. At an appropriate time, we will decide on whether to continue the assessment process and will trigger another round of public consultation.
Rössing conducted its exploration work at the Z20 uranium ore body in three phases. The first of these, carried out between 2010 and 2011, defined the position of the resource. We completed the second-phase drilling programme on a 100m x 100m grid pattern in March 2012. The third phase, narrowing this area down to a 50m x 50m grid, saw completion in April 2013.
To comply with the requirements of the Department of Parks and Wildlife Management and the mine's Environmental Management Plan to guide our exploration work in the Namib-Naukluft Park, by the end of May 2012 we had completely rehabilitated the area which had been disturbed by exploration activities during the second phase.
The encouraging results of the exploration work led to the now completed third phase of drilling. We also conducted a thorough clean-up of the site after the end of the third-phase drilling programme, but still need to address final rehabilitation of the site. The Department of Parks and Wildlife Management agreed to our proposal to postpone rehabilitation to June 2014. By this date we would have a better idea of whether to conduct immediate development work or whether to allow the exploration site to remain dormant for the foreseeable future.
We have already set aside adequate funds for such rehabilitation, and the identification of suitable contractors will commence in early 2014.