Managing our water resources
- 8,284,039m3 RA total freshwater consumption, 4.43% lower than in 2012.
We have emphasised regularly that the water scarcity risk facing South Africa is one of the greatest challenges to the country’s economic development. This is particularly true in provinces such as the North West and Limpopo where the infrastructural capacity to store and transfer water is so limited and where long periods of drought are common. The risk to Lonmin’s business and the mining industry in general is even more urgent, given the sector’s significant dependence on water resources and the priority that is given by government to other uses such as ecological reserves, international obligations, inter-catchment transfers, agriculture, domestic consumption and strategic future allocations.
The International Council on Mining and Metals (ICMM) has confirmed the urgency of this risk for the industry and has embarked on a water management strategy to support member companies in the implementation of cost-effective water conservation efforts.
Our response to this challenge is outlined in our Integrated Waste Water Management Plan (IWWMP) and our Water Conservation and Water Demand Management Strategy (WC/WDMS). The strategy aims to:
- Secure access to sufficient water to supply our operations and sustain our Life of Business Plan.
- Optimise our freshwater consumption and use process water more efficiently.
- Minimise the contamination of ground and surface water resources around our operations, with a view ultimately to reducing our closure liabilities.
The central tool of the Water Strategy is our Integrated Water Balance, (IWB), which uses specialised software to integrate the business variables that have an impact on water resources and simulate accurate planning scenarios and risk assessments in real time.
The information that we obtain from the IWB informs every aspect of our Water Strategy and Integrated Waste Water Management Plan. These range from on-site storage optimisation to the minimising of dewatering and pumping requirements and the prevention of water from opencast areas entering into shafts. Water security and the prevention of decant is also a critical component of mine closure and the Integrated Water Balance has a significant role to play in determining sustainable mine closure options.
The implementation of the IWB is an eight-year project.
Aquifer Storage and Recovery
The on- or near-site capture of water has always been a challenge, simply as a result of the inadequacy of infrastructure. Aquifer Storage and Recovery (ASR) is a specific type of artificial recharge which could solve this problem. It involves the sub-surface storing of water in natural aquifers, to prevent losses due to evaporation, and is usually achieved by allowing water to penetrate the subsurface via infiltration basins or injection boreholes and be recovered via the same borehole.
Of Marikana’s 34 opencast pits, 31 have been backfilled. These ‘anthropogenic aquifers’ are usually more porous than the surrounding rock and are often shallower and better confined than natural aquifers, thereby creating ideal conditions for the underground storage of large volumes of water. They are by definition, near centres of mining activities and thus present significant water storage and re-use opportunities for the industry as a whole. This initiative was implemented at our central operations in May 2013 and is currently being developed for implementation at our Karee opencast pits to provide water to the Karee mining operations. These water storage activities are also covered by our integrated water use licence.
Other studies that have stemmed from the Integrated Water Balance include:
- 3D groundwater flow model, in order to analyse the flow through the bottom of the pits or underground developments, which should be completed in 2014.
- Salt balance to predict salt concentrations in groundwater at various locations on site, on track for completion at the end of 2013.
We continue to source our fresh water for Marikana and the PMR operations from Rand Water, which transports water over the Magalies Mountains to the Rustenburg area from the Vaal Dam in Gauteng. In Limpopo, our fresh water is drawn from the regional well fields. Both sources are authorised under each operation’s IWUL.
Fresh water consumption
Our total fresh water intake for 2013 was 8,284,039m³ RA, from Rand Water, Buffelspoort Canal and from the Limpopo well fields. This is 4.43% lower than the 8,667,896m³ used in 2012, which has been largely due to the increased use of process water.
We were able to maintain our water efficiency, indicating our consumption per PGM ounce produced, which was recorded as 6.20m³ per PGM ounce in 2013 compared to 6.42m³ per PGM ounce in 2012. This marks a 3.4% decrease year-on-year.
Recycling and re-use
The use of closed system reticulation is still our primary means of recycling process water, and as far as possible, we contain our process water in this closed system. We were able to recycle 31 million m³ of process water during 2013 (2012: 27 million m³). This increase reflects that our Integrated Water Balance is starting to take effect.
We own and operate seven waste-water treatment plants around our Marikana operations.
Two of these also treat sewage volumes from the GLC. One of the plants at our Western Platinum Limited (WPL) operations purifies 5.5Ml of sewage per day from the villages of Marikana West and Marikana North (approximately 650 RDP houses) while the Mooinooi plant treats 2.5Ml of sewage from Mooinooi daily. All final effluent generated during the treatment process meets current standards on-site, and is re-used as input process water at our operations.
Although the provision and maintenance of sewage treatment infrastructure is a local government responsibility, we provide assistance to clear sewage blockages that are brought to our attention through our formal stakeholder engagement structures, and the provision of tanker discharge points for the disposal and treatment of community effluent.
- Total water withdrawal by source.
- Water sources significantly affected by withdrawal of water.
- Percentage and total volume of water recycled and reused.
Seven discharge incidents were reported and investigated in 2013 (2012: eight). According to our sampling, the environmental impact of these discharges was limited and none of them had a significant impact on any protected or biodiversity-sensitive water bodies.
Process water at our operations is contained as far as possible within a closed system. The major challenges in this regard are the overflow of return water dams during the rainy season and the ingress of fissure water from underground.
We have preventative as well as management procedures developed for discharges. The following indicate the measures taken to prevent and manage discharges:
- The daily and weekly monitoring of the freeboard of return water dams.
- Communication of emergency situation. When dam reaches emergency levels, at 0.85m freeboard, an emergency situation is declared. The engineering manager notifies the SHERQ specialist, who distributes a communication to all on a defined distribution list of business units supplying water to the return water dam.
- Immediate action once safety risk has been assessed. Response occurs within 24 hours of receipt on information, for the approximate volumes of water that can be held back within a defined allocated period of time. Should the shafts not be able to hold back water (due to the risk of shafts flooding), water received from the sewage water treatment works will be stopped and return water will be used in its place (where practicably possible) in the concentrator plants. Alternatives, such as running increased irrigation system usage on the tailings dam and raising the penstock are considered where and if practicably possible and where no risk to the stability of the dam is envisaged.
- Discharge. If all alternatives have been exhausted and there is no other option but to discharge, discharge notifications are sent to the Department of Water Affairs.
- Return to normal conditions. When the water level of the return water dam drops to below 0.9m, the normal operation of the return water dam will be resumed in phases. Water will be released from temporary storage facilities at the shaft areas at a predetermined schedule.
We stated in 2012 that we would be able to prevent any discharges into the environment from the Marikana return water dams and waste water treatment plants by 30 September 2014. This commitment was however unrealistic, given the seasonal variances and the possibility of flooding and extensive fissure water strikes which could result in discharges and which cannot be prevented. As indicated above, we do have management and mitigation measures in place which reduce the likelihood of a discharge occurring.
We have 211 borehole monitoring sites which we check continuously for potential groundwater contamination, quarterly at Marikana and bi-annually at Limpopo and the PMR. The groundwater samples are compared quarterly with SANS 241 Standards for drinking water and are also tested for electrical conductivity.
Surface water quality is monitored monthly at 109 sites throughout our operations. These monthly samples are analysed for pH levels, total dissolved solids, suspended solids, electrical conductivity, water hardness and any presence of ecoli. A baseline audit was recently conducted with the issuing of our IWUL for Marikana. Internal compliance audits with any legal requirements and with our ISO-certifications are completed every two years.
Acid mine drainage
Due to the nature of the ore that we mine and the manner in which we process it, we do not generate acid mine drainage from our residue waste stockpiles. The nature of the tailings material disposed of on the tailings dam is alkaline, not acidic, and results in very little leaching of heavy metals into ground water.
- Total water discharge by quality and destination.
- Identity, size, protected status, and biodiversity value of water bodies and related habitats significantly affected by the reporting organizationís discharges of water and runoff.