Closure as a component of mine life planning
Closing a mine does not simply mean shutting down production, rehabilitating the land and walking away. People's livelihoods can be affected, as can the social and environmental programmes established during the life of the mine.
Integrating closure planning into all aspects of decision making, from the earliest stages of project development to decommissioning facilities, is crucial to leaving a positive legacy of sustainable development.
At the Kestrel underground coal mine in central Queensland, Australia, we have been planning for closure, or "mine life planning", since 2006 - even though the expected mine life is for a further 20 years. Mine life planning underlies the mine's overall plans, and is also at the core of the expansion project that has been approved by Rio Tinto and its joint venture partners in Kestrel.
In 2006 we conducted a social and economic study of the region. We asked the local community (including employees) for their thoughts around the potential impact of the mine closing. We also asked them for their vision of post closure land use, and shared our closure ideas with them. We found that we held similar expectations.
The community wanted assistance in maintaining a diversified region, including returning the land to a stable and sustainable use. This vision is aligned with the Rio Tinto Coal Australia preferred closure option that includes agricultural land predominantly for beef cattle grazing and wheat and soybean crops, integrated with native habitat. Local communities did not consider the closure would generate major impacts, as only two per cent of the mine's employees at the time are expected to live in Emerald, the closest major town.
As part of the mine life planning process, we identified key environmental issues, which were also in line with the community's thinking, including:
- groundwater impacts
- surface and groundwater management; and
- rehabilitation of land including subsidence
Further research found that there was no significant difference to the growth of wheat and soybean crops on land disturbed by mining compared to undisturbed land. We will be conducting similar investigations regarding grazing yields. And we will continue to conduct investigations into surface and groundwater modelling and monitoring, to understand better the actual and potential impacts of closure on water users and the environment.
Research outcomes drive mitigation programmes, which we incorporate into mine life planning.
Approaching closure as part of mine life planning enables us to honour our commitment to sustainable development. It allows us to adapt the design, development and operation of our mines to optimise post closure outcomes around social and environmental issues and economic development.