Re-thinking our model of mine rehabilitation and closure—is it time for a new model of mined lands stewardship?

Abstract

In Australia, as in many jurisdictions, (apart from the USA where the situation is more complicated) earth resources are typically owned by government. Mining companies apply for mining leases to extract those resources. A royalty is paid to the government as consideration for the extracted resource. Extracting mineral and petroleum resources has impacts. Open cut mining creates voids and out-of-pit waste structures. Underground mining may result in subsidence and waste structures on the surface. Ore beneficiation creates waste streams that can lead to environmental impacts, such as the daylighting of materials long sequestered underground. Many long-lived mines have not retained viable topsoil, or those that have can still face deficit challenges, simply from the new geometry and bulking volume of disturbed materials forming waste structures. These impacts are well-known and have been apparent for decades. When governments approve a mining lease, the expectation is that the land will be restored to its pre-mining state, that ecosystems can be restored, that agricultural lands can be reintroduced into production. However, we see that globally, the examples of complex mines returning to a safe, stable, non-polluting state, capable of sustaining a post-mining land use, are modest, to say the least. Yet we see this expectation or variations on it, persist around the world. At the same time global demand for natural resources, especially those facilitating the transition to a low-carbon economy, continues to increase. It is time to explore new paradigms of mined land stewardship - models in which governments and miners take on new responsibilities for the impacts from natural resource extraction. A new paradigm would not see regulators and miners so much ‘meet in the middle’ as move respectively towards management regimes that protect our limited natural resources, the environment, and the social-ecological systems in which mines operate. This paper reviews the status of ‘successful’ mine closure, presents some of the behaviours apparent in the industry regarding mine closure, and proposes some potential opportunities to re-imagine the mine closure task from a liability-laden burden to a long-term stewardship model.