Since its launch in 2020, the GISTM has been widely adopted, with investors actively voting against company chairs who have not confirmed their intention to meet the GISTM and many mining companies setting ambitious deadlines for compliance with the rigorous criteria. The target for operators that are electing to be GISTM compliant is to achieve it within five years (by mid-2025).
While the immediate focus has rightly been on the highest risk and predominantly operational TSFs, requirements will be equally applied to inactive, remediated or closed TSFs. These latter groups can often represent a substantial part of a mining company’s TSF inventory. For example, as of 2021, BHP’s portfolio of 73 TSFs included 59 inactive or closed facilities, Newmont’s portfolio of 90 TSFs included 69 inactive or reclaimed/closed facilities and Barrick’s portfolio of 70 TSFs included 50 inactive or closed facilities. This means over 70% of the TSFs within large mining company portfolios are non-operational.
Similar to operating TSFs, the risks posed by inactive and closed TSFs are site-specific, based on the environmental and social setting, original design of the TSF, nature of material stored, operating history, status of documentation, rehabilitation and closure activities completed. For those inactive and closed TSFs, the application of GISTM requirements will focus on moving the TSF towards a state of ‘safe closure’ at which point GISTM requirements no longer apply. TSFs in ‘safe closure’ do not pose ongoing material risks to people or the environment, as confirmed by an ITRB or senior independent technical reviewer and signed off by the Accountable Executive.
The transition through closure to ‘safe closure’ as defined by the GISTM is focused on achieving zero harm to people and the environment. However, closure doesn’t just need to be thought about in the language of risk. Closure can also present opportunities for legacy TSFs to become valuable assets for mining companies. This could include repurposing the closed mine to fulfil a new land use, like conversion into renewable energy sites. It could also involve avoiding the implementation of closure activities altogether by reprocessing the tailings material to extract economic minerals or to provide an alternative supply of sand for the global construction industry. In the same way adherence to GISTM requirements requires a multi-disciplinary team, identifying and realising these opportunities will require tailings engineers, social performance practitioners, mine planners, environmental scientists and closure specialists to share a common vision and collaborate effectively.
