Mining for Closure: Policies, practises and guidelines for sustainable mining and closure of mines

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closure and abandonment of mines

many reasons and almost at any time. Many min- ing legacies are much more than the result of mine abandonment in the absence of legal and regulatory frameworks to ensure adequate decommissioning works. 67 In many instances they have been a part of larger economic or social situations that are in themselves stressful for communities dependent upon mining – and may in themselves have con- tributed to the cessation of mining activity. Factors contributing to cessation of mining activi- ties include inter alia (largely after Environment Australia (2002a; 2002b), and Smith & Under- wood (2000): depletion of mineable reserves, that is as a re- sult of the total extraction of the mineral re- serves within the physical limits of a deposit or the mine area; unexpected changes/deterioration in geologi- cal conditions; changes in market conditions; changes in other external economic factors that make reserves unworkable at a given time (changes in liability conditions should be in- cluded in this category); financial (non)viability of the company; adverse environmental conditions or; adversepolitical conditions or social disruption. Further, it is important to note that in some cases mining may only be suspended for a period of time and the project is placed under care and mainte- nance (Environment Australia, 2002a). How long this period is – or how intensive the degree of “care and maintenance” is, may vary significantly (Envi- ronment Australia, 2002a, 2002b; Environmental Protection Agency, 1995a; Robertson & Shaw, 1998; Robertson, 1998). However, in circumstances where it is clear that economic or other limits of the opera- tions have been reached, decommissioning and fi- nal closure is required for such sites as well. In some instances, the delineation between a mine officially categorised as being on care and maintenance – and one that is abandoned may be difficult to make. • • • • • • •

This section is intended to provide more back- ground in three key areas. Firstly, the reasons for mine closure are addressed and these underlying reasons are linked to possible outcome scenarios – some far less desirable than others. Secondly, the global problem of abandoned and orphaned mine sites and the types of initiatives required to deal with this problem are discussed. Thirdly, the general form of stakeholder expectations regarding mine closure is presented. These expectations are then juxtaposed with closure requirements on the one hand and emerging post-closure considera- tions on the other. 4.1 New orebodies and mineral resources are con- stantly being discovered through exploration but the reserves contained in any particular deposit on which a project is based are finite. All things being equal, it is thus logical that all mining activities at a certain mine site must come to a close at some stage within a foreseeable future. In much of the previous discussion, it has been in- dicated that the overall mine decommissioning process should be integrated with the overall mine operation planning process . This appears in many instances to bear with it an implicit assumption that mine decommissioning usually occurs at a point in the life of an operation where the economic recovery of minerals has ceased according to some plan . Further, that this cessation is an ordered outcome. If earlier discussions of integrated mine planning hold, then it is feasible that a mine can be designed and op- erated with a continual focus on expected closure outcomes and according to a well-known timetable. As such, a process of progressive decommission- ing should be undertaken. This is of course feasible and some mines have been designed operated and closed according to predetermined plans. However, this has hardly been the standard modus operandi of mining. His- tory has shown that mining activity can cease for why do mines cease activityandhowdoes this affect closure?

67. The reader is reminded, that until relatively recently in a limit- ed number of countries, that decommissioning and closure works were generally not required.

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MINING FOR CLOSURE