Demolition – the forgotten closure strategy
Abstract
Historically regulators, mining companies and consultants have focused their closure planning and implementation activities on the environmental and rehabilitation aspects of mine closure. This process has involved the mitigation of potential long-term pollution risks and the reinstatement of landforms which are generally safe, stable and compatible with the surrounding ecosystem.
More recently, in response to growing social pressure and increased triple bottom line accounting, the community or social aspects of mine closure planning and implementation have received increasing attention. This has resulted in significant advances in the mining industry’s approach to the mitigation of post closure socio-economic impacts and the consideration of community capacity development beyond mining.
A third aspect of mine closure, the demolition and removal of infrastructure, however, has yet to receive much attention within current closure planning activities. Despite demolition costs contributing up to 50% of total estimated closure costs, demolition strategies within closure plans are generally based on the simple assumption that infrastructure will be removed by a demolition contractor and disposed of in an appropriate manner. Few contemporary closure plans identify or evaluate alternative demolition strategies or provide for further investigation into the development of demolition strategies which contribute to sustainable mine closure outcomes.
The framework for sustainable development within the mining industry recently developed by the International Council on Mining and Metals and the associated implementation guidance developed by the Minerals Councils of Australia now provide a new perspective from which to re-evaluate alternative demolition strategies. This perspective is further enhanced by guidance documentation, such as the Australian Government’s leading practice booklets on mine closure and stewardship, as well as the emerging corporate policies and standards.
This paper identifies a number of alternative demolition strategies including retention, re-use, demolition, salvage, and recycling. The specific details of these strategies are presented and their conformance to current sustainable development principles discussed against legal, technical, commercial, social, environmental and economic factors.
It is concluded that current market forces, design practices and legacy issues are likely to create uncertainty in the selection of a preferred demolition strategy. The implications of these findings are discussed in regard to future market status, current maintenance practices and, design and construction processes.
Author
D.P. Murphy, Sinclair Knight Merz, Australia
R.C. Marshall, Ross’s Auctioneers and Valuers, Australia
G. Duff, Sinclair Knight Merz, Australia