Integrated Annual Review 2012 Annual Financial Report 2012 Mineral Resources and Mineral Reserves Regional overview  

5.3.2 Using and discharging water responsibility

Water management represents a key potential risk in all of the regions in which we operate. It forms a key component of each of our operations’ Environmental Management System (EMS) – through which water use and quality is assessed, managed, monitored and reported on.

Water strategy

In 2012, our Group Technical Services (GTS) function started scoping activities for the development of a Group-wide water strategy. This is being supported by a newly formed, world-class team of water experts at Group-level headed by a new Group Head of Water Management to ensure we address heightened levels of scrutiny from national water regulators and other stakeholders in an early and proactive way. This included a prioritised review of water management at our Tarkwa mine, which produced a comprehensive action plan to further enhance:

  • Water management plans and systems
  • Water balances
  • Operational procedures
  • Roles and responsibilities
  • Laboratory standards

This will act as a model for similar water management reviews to be rolled out across the Group.

Case study: Driving best practice across the Group through the new water strategy

Tarkwa Heap Leach closure

In July 2012, Ghana’s Environmental Protection Ageny (EPA) directed us to suspend all discharges of water from our North and South Heap Leach facilities at Tarkwa. The EPA further required that instead of utilising longstanding dilution methods, which had ensured that we were discharging within regulated limits, all such discharges should be treated through a water treatment plant to reduce conductivity levels (i.e. the amount of dissolved salts rather than any indication of toxicity per se). Although the EPA had permitted the dilution method for several years, we nonetheless:

  • Suspended discharges as part of our commitment to strong environmental stewardship and compliance with the EPA directive
  • Commissioned the construction of two water treatment plants at the mine
Figure 5.16: Group water withdrawal
  Figure 5.17: Group water withdrawal per
ounce of gold produced (pre-unbundling)
Figure 5.16: Group water withdrawal (pre-unbundling)   Figure 5.17: Group water withdrawal per ounce of gold produced (pre-unbundling)

In August 2012, the EPA lifted its suspension of activities at Tarkwa’s Heap Leach facilities and – along with Ghana’s Ministry of the Environment, Science and Technology – approved the continued dilution and discharge of excess water within existing legal limits, pending the completion of our two new water treatment plants by 31 December 2012. It is estimated that the 24-day suspension resulted in lost production of 15,000 ounces – less than 10% of the mine’s quarterly production.

The water treatment plants were both operational by the end of March 2013.

In addition to implementing the action plan produced for Tarkwa through our water management review, we have also instituted enhanced water monitoring at the mine – on top of our existing joint water monitoring with local community members (p149). This includes an increase in the number of sampling points and more frequent testing.

Water use licences in South Africa

The Kloof mine (part of KDC) was issued a water use licence in December 2008 that expired in December 2011. The Group has applied for renewal of, and amendments to, this licence. Pending approval of the Kloof water use licence, a regulatory directive was obtained from the Department of Water Affairs (DWA) that permits the continuation of water uses at the Kloof operation. The Driefontein mine (also part of KDC) was issued a water use licence in October 2010. Discussions with the DWA are ongoing to revise the licence.

The DWA has advised the Beatrix operation, which had pre-existing water permits of indefinite length, that its current water usage remains authorised and that it need not apply for a new licence. However, Beatrix has nevertheless proactively submitted a water use licence application, which is currently being processed.

Gold Fields was issued a new water use licence for South Deep in December 2011 and has subsequently made an application for rectification and amendment of this water use licence to the DWA.

Liquid Gold strategy

Liquid Gold is a joint Gold Fields/ Sibanye Gold project to proactively prevent future acid mine drainage (AMD) from the deep underground KDC and South Deep mines (i.e. once they reach their respective mine lives – at least 10 to 20 years away in the case of KDC and more than 50 years away in the case of South Deep).

In 2012, we conducted a comprehensive scoping exercise to help move our Liquid Gold strategy towards feasibility stage in 2013. This includes moving beyond our previous focus on potential treatment options to materially advancing planning around a sustainable, reliable and integrated post-closure water strategy, which takes account of potential impacts within the wider Wonderfonteinspruit catchment area. In addition, we are integrating evolving water treatment methodologies to take account of relevant technological advances.

The strategy now envisages the provision of treated potable and industrial water pumped from closed operations – and using the revenues generated to finance AMD avoidance measures, such as ongoing separation of clean and dirty fissure water and selective water treatment.

Avoidance measures would be based on two separate pumping and treatment systems – one higher-volume system for AMD-affected water and a smaller volume system for clean fissure water – as well as the appropriate sealing of underground contact points between the two, to minimise potential mixing.

In addition, we are examining opportunities as to how Liquid Gold can also be used to support our Surface Treatment Strategy (p95), which is likely to require significant amounts of water.

AMD at Cerro Corona

AMD is considered both a short-term and long-term risk at our Cerro Corona mine. A number of controls have been successfully employed at the operation to ensure that AMD is well managed throughout the mining life cycle. These include:

  • Implementation of a full life cycle risk mitigation strategy
  • Full integration of AMD issues into the Environmental Management System
  • Continuous and extensive leach testing, using methods that exceed industry best practices
  • Integration of AMD mitigation measures into the design of all the components of the operation
  • Continuous monitoring of the performance of these mitigation measures

As part of Cerro Corona’s mine closure plan review, Gold Fields recently concluded studies required by Peru’s Ministry of Energy and Mines (MEM) to analyse post-closure water treatment requirements. The MEM found that Cerro Corona will require post-closure water treatment, which represents a change to Cerro Corona’s previous closure plan. Gold Fields is in the process of consulting with the MEM regarding its post-closure plans.

Case study: Why is AMD of such public interest in South Africa?