Mine closure plan – a living, iterative effort

MINE CLOSURE

Mine closure plan – a living, iterative effort

While most businesses tend to focus on the here and now – rather than on any prospect of closing down – a mine bears the responsibility of planning its closure even before it starts.

By James Lake*

With more than 23 years of experience in the environmental field, James’ focus is on geochemistry, closure planning and liability estimating Today’s expectation is that a mine closure plan is dynamic, requiring constant and regular improvements. This, of course, has not always been the case, and there are still plenty of examples of mine closures that have not been at all planned. South Africa’s legacy of about 6 000 abandoned mining operations is testament to that. Partly for this reason, times have changed radically, and mine closure is now a central concern of responsible mining companies and governments globally.

It has been a few years since the International Council on Mining and Metals published the second edition of its Integrated Mine Closure Good Practice Guide, and this remains the standard reference point for practitioners.

Dynamic process

If there were a central point these guidelines drive home, it would be that mine closure is a dynamic and iterative process. This makes it vital to consider closure as an integral part of mining operations’ core business – which in turn demands a systematic and integrated approach. To achieve this integration into life-of-mine planning, mines need to develop and update a detailed knowledge base, where data can be used to inform the ongoing relevance of the plan. The mechanisms here are feedback loops, turning closure-related actions into a cyclical process where the plan is modified as more information becomes available.

Perhaps the other key aspect of international good practice is that it considers not just environmental, but also social and economic, factors in the closure

MINE CLOSURE

strategy. Over the years, the trend to emphasise social issues led practitioners to talk about ‘social closure’ to highlight this aspect. More recently, though, the necessary integration of environmental, social and economic issues is being readily embraced; the more appropriate focus is now on socio-economic transitioning.

Such transitioning demands not just planning but communication. Underpinning the principles of responsible closure has increasingly been a focus on engaging with stakeholders – most importantly those in mining communities most directly affected by closure. This holds a special relevance for South Africa, where many mines are labour-intensive and can often employ many thousands of workers. Add to this the structural poverty within the economy and, because each of these workers supports 5 to 10 direct dependents1, the socio-economic scale of closure is significant.

Engagement

This highlights the potentially catastrophic human impact that closing a mine can have, aside from the myriad environmental impacts that may continue after closure. Engagement has therefore become an essential and specialised task, not only to understand community needs and aspirations, but to communicate the many essential truths about the transience of mining.

In a recent engagement exercise at a local mine nearing the end of its life, it became clear that many community members struggled to comprehend a time

Responsible mine closure remains a fundamental aspect of the mining sector’s sustainability approach

Early implementation of rehabilitation during operations resulting in sustainable covers (Credit:JamesLake)

MINE CLOSURE

Tailings closure incorporating drainage designed for anticipated future rainfall (Credit: James Lake)

when the mine might not be there. The knowledge that the mine had operated for decades often creates the mistaken impression that it is a permanent fixture. Modern industry standards place responsibility on the mine to educate stakeholders about why closure planning is necessary, and why they need to be involved. Only in this way can efforts to diversify local economies gain traction, for instance.

In the same way that closure planning is an ongoing task, so then is stakeholder engagement. In our experience, mines usually find that their closure messaging needs to be repeated as people move through mining communities. The engagement must address new generations of existing residents as well as waves of new residents moving in from elsewhere. Social engagement has therefore become an increasingly important aspect of the specialist services that SRK provides.

Climate change

Environmental aspects remain core to closure plans, and indeed have become more complex with the advent of climate change. An important concern has been fast-changing rainfall patterns, where variations in volumes and intensity have the potential to threaten the integrity of large structures like tailings storage facilities. These changes are likely to make new demands on the design of drainage structures, for example. Intense rainfall could also erode cover systems put in place to bring vegetation back to a mined area or a dump site. These demands are reflected in the evolution of skill sets to manage tailing dams – a field in which SRK has been extensively involved over the decades. In the modern era, mine closure planning in relation to tailings dams requires multidisciplinary teams, including specialists in geotechnical engineering, as well as water management and environmental rehabilitation.

Putting aside funds

Financial provisioning has also been a key issue in mine closure, although this has not yet been conclusively dealt with following the promulgation of relevant legislation in 2015. The aim is to ensure that mining companies have the resources to implement proper rehabilitation in the closure process. This is understandable, as the state should not be expected to do this – neither does it have the resources to do so. However, there is still discussion about the actual amounts to be set aside as provision, and a new version of legislation is expected in 2022.

Notwithstanding the challenges and complications, responsible mine closure remains a fundamental aspect of the mining sector’s sustainability approach. Apart from being a legal requirement, it also underpins the industry’s reputation going forward as it works to establish a more constructive relationship with stakeholders and regulators alike.

*James Lake is a partner and principal scientist at SRK Consulting.