The art, or is it science, of mine closure is still a youngster. There is no agreed fundamental philosophy or even technical approach. This is strange when you consider that mining has been around for a long time and many mines have been worked out. Most have been abandoned as the many abandoned mine remediation programs attest. Only in the past few years have we seen vigorous debate on the need for planning and contentious mine closure. Much of this debate has been documented in the proceedings of the Mine Closure Conferences organized by the Australian Center for Geomechanics. Yesterday I spent some time paging through the past conference proceedings. Here are two extract that, to my mind, nicely capture the dilemma of those seeking a consistent philosophy of mine closure.
The most telling case for addressing community concerns on mine closure is made by R.J. Lambeck (Mine Closure 2009). He writes:
While mine closure has traditionally been seen as the cleaning up job at the end of the extraction process, community expectations of industries that significantly impact the environment and society are changing. Meeting these expectations requires a change of mindset: mine closure is seen as one component of a whole life cycle obligation to maximize the positive environmental and social consequences of the mining endeavor. This involves a shift from models of trade-off to ones of net benefit across the three pillars of sustainability: environment; society; and the economy. Can companies legitimately claim that, as a consequence of their existence, the world is environmentally, socially, and economically, better off? Aspirations to be able to make such claims requires managing the company’s footprint —avoiding, minimizing, or offsetting social and environmental impacts across the whole of its operations and life cycle, not simply cleaning up the mess at the mine.
This argument and many more like it make a powerful case for laws, regulations, enforcement, and practice that lead to the opening of only those mines that can be closed in such a way that they leave behind a better environment, society, and economy than existed when the mine was opened.
On the other side of the coin, consider that while the closed mine may have no economic value to the company closing the mine, in a third world countries the closed mine may be a source of valuable materials and a possible subsistence livelihood. Consider what the Reichardts (Mine Closure 2007) say of mine closure in Africa:
Accept the reality of trespassing by humans and animal and consider this in the identification, assessment and implementation of effective closure methodologies. Accept that ultimately barriers such as fences and bunds, while potentially helpful in the short-term, are not effective in preventing human and animal access over the medium to long-term. Identify physically and socially effective mechanisms of access control (other than physical barriers) to ensure that rehabilitated areas remain undisturbed during critical periods of rehabilitation and closure. Manage waste and waste disposal in a manner that extracts recyclable materials during the operational phase, leaving nothing of residual value that might attract scavengers. Generally involving the community in the separation and recycling of such materials will reduce the risk of subsequent scavenger activity, as the community calculation will have already been applied to the materials that will be left behind. Create and communicate an operational reality on site that dispels any myths among employees concerning the benefits of subsequent trespassing, scavenging, and scavenger mining for scrap and other items of potential resale value, particularly in a setting of limited economic opportunity and poverty. Implementing effective access control to prevent illegal miners accessing closed mines or worked out sections of operational mines remains an intractable problem for which there is no obvious solution. Heightened security may help restrict illegal access in the operational phase, but it is unlikely to be either practical or effective in the post-closure phase, particularly where the community perceives that potentially economic ore has been left behind.
This passage sent me back to thinking of a diamond mine in Botswana that I once visited. The rule was simple: once a piece of equipment entered the double security fence, it never came out. This made sense as a way to control the temptation to smuggle diamonds out of the secured area. The result was that around the perimeter of the tailings impoundment there was a vast junk yard of old cars, trucks, office equipment, mining debris, and paper which did not deteriorate in the dry desert. Here was a venerable cornucopia of metals, wood, plastic, and paper. Maybe even a carelessly discarded diamond. I wonder if the mine will ever “close” this part of their waste disposal facilities or if they will allow the locals in at closure to mine what may, for them, still be a resource. I know those two security fences will not last long.