Stakeholder expectations relating to mine closure, as well as scrutiny from regulators and NGOs, are increasing. As the mine closure landscape changes, regulations have become increasingly stringent. This applies to both expectations of the industry’s closure performance and companies’ disclosure of mine closure costs.
The ability of mining companies to responsibly close their operations – while, at the same time, reducing their environmental and social impacts – is critical to their social licence to operate. To this end, Gold Fields has strengthened its approach to closure liabilities over time by requiring operations to:
During 2021, the Group maintained its focus on progressive rehabilitation – the implementation of closure activities during the construction and operation of a mine. Group spend on progressive rehabilitation increased to US$24m in 2021 (2020: US$14m).
Progressive rehabilitation includes closure-related technical studies and designs, remediation of contaminated areas, decommissioning and removal of redundant infrastructure, landform reshaping, rehabilitation, re-vegetation and in-pit waste rock disposal. The Group achieved an average of 93% of the measures set in the rehabilitation plans for 2021, ahead of internal targets.
Substantive projects undertaken during 2021 included the rehabilitation of Tarkwa's heap leach processing infrastructure, industrial waste site clean-up at South Deep, TSF safety and stability buttress installation at Granny Smith and rehabilitation trials at Gruyere.
Gold Fields' total gross mine closure liability increased by 9% to US$510m in 2021, largely due to additional liabilities at Salares Norte, as well as additional closure requirements and post-closure contingent liability mitigation measures at Cerro Corona (US$29m). This was partly offset by progressive rehabilitation measures implemented at the other mines.
The regional breakdown is provided in the table below:
|Group closure estimates (US$m)||2021||2020|
|1||Includes 50% of the total Gruyere closure cost estimate|
The funding methods used in each region to make provision for the mine closure cost estimates are: