Mine Closure - Mining and the Environment: From Ore to Metal - page 800

history of man-made degradation. In many such cases, rehabilitation provides the oppor-
tunity for substantial functional improvement in terms of productivity, biodiversity or
both. Common examples include lateritic areas where shallow caprock provides a physi-
cal barrier to root penetration for many plants. Removal or fragmentation of the caprock
improves the situation, enabling establishment and maintenance of a more diverse range
of plant and animal species. Again, some environmental purists will argue that depauper-
ate natural areas are preferable to 'unnatural' areas of higher productivity and diversity.
Naturally infertile or physically constrained systems may indeed have valuable or unique
attributes which warrant preservation. If so, such attributes can be preserved by estab-
lishing conservation areas. In fact, such areas are commonly over-represented in the con-
servation estate compared to areas of high productivity, because they tend to be in public
ownership, whereas productive areas have always been in demand for agriculture and
hence tend to be privately owned.
This said, prior to 1985, the issue of mine closure had a low priority for most govern-
ments (and hence for most companies), as evidenced by the large numbers of abandoned
mines that exist in virtually every major mining country. Very few countries had in place,
and the majority still does not have, mineral policy and legislation that provide for compre-
hensive mine closure (Clark and Cook Clark 2000). The basic components of a comprehen-
sive mine closure policy and associated legislation, as further detailed in this chapter, would
(1) have a comprehensive mine closure i nancing programme; (2) provide specii c provi-
sions for abandonment and post-closure activities; (3) provide specii c provisions for reha-
bilitation; (4) require an Environmental and Social Impact Assessment; and (5) have specii c
monitoring and enforcement procedures to ensure compliance (Clark and Cook Clark
2000). Most if not all countries with a history of mining have legacies of problems from
abandoned mines. To date none have devised appropriate and cost-effective means of deal-
ing with the issue, although some countries are well advanced in tackling the problems.
By some estimates there are more than 500,000 abandoned mine sites in the USA alone
(USEPA 2000; UNEP and Chilean Copper Commission 2001). Today a number of coun-
tries (e.g. Australia, Bhutan, Bolivia, Burkina Faso, Canada, Indonesia, the Lao People's
Democratic Republic, Mongolia, the Philippines, UK, USA, Vietnam and Wales) have
established comprehensive policy and legislation that provides both for mine closure and
for post-mining sustainable development. With the exceptions of these countries, whose
policies and legislation have been implemented to varying degrees, the majority of the
world's largest mining countries have inadequate policies and legislation for comprehen-
sive mine closure in place, and still fewer provide for post-mining activities and sustain-
able development (Clark and Cook Clark 2000).

Prior to 1985, the issue of mine
closure had a low priority for
most governments.

21.1 REASONS FOR MINE CLOSURE

According to Laurence (2006) in a survey of Australian mine closures since 1980, only 25%
of the 800 mine closures examined occurred following resource exhaustion or depletion. The
remaining closures were due to a variety of causes including economic, geotechnical, safety
and hydrological causes. This means that up to 75% of closure were either unplanned or
were hurriedly planned over a very short period. These i gures, however, may be somewhat
misleading in terms of the total mining industry, as the vast majority of closures involved
small or medium operations. The larger mines which are mainly operated by large min-
ing companies, tend to operate until the resource is depleted, although there may be signii -
cant l uctuations in production or even interruptions, as a result of l uctuating demand.