Mine Closure - Mining and the Environment: From Ore to Metal - page 801

These larger mines account for most of the production of most commodities except, possi-
bly gold, where the numerous small producers make a substantial contribution. In fact gold
mines accounted for about 50% of the 800 mine closures in the survey.
It follows from this survey that many mine closures are either unplanned or inade-
quately planned. It is in this context that most host countries now require some form of
i nancial assurance to ensure that funds are available for decommissioning and rehabilita-
tion of a site in the event that the operator does not fuli l its obligations and commitments.

Many mine closures are either
unplanned or inadequately
planned.

21.2 OBJECTIVES OF MINE CLOSURE

The main objective of mine closure and land rehabilitation is to return as much as possible
of the land disturbed by mining to a condition in which it can sustainably support one or
more pre-determined land uses. Within this overall objective there will be a number of
secondary goals, including:
●

Restoration of public safety;

●

Stabilization to avoid landslide, serious erosion or surface collapse;

●

Removal of components which are incompatible with the intended land use (these
include plant, equipment and buildings);

●

Removal, immobilization or safe burial of toxic or hazardous materials from mining
operations;

●

Restoration of hydrologic functions, involving the storage and/or release of rainfall;

●

Restoration of visual amenity.

Sometimes, mineral resources will remain within the area, in which case there may be
another goal - to facilitate access to these resources should they become economically
mineable in the future.
Arguably the most important factor in mine land rehabilitation is the establishment and
maintenance of public safety. Risks associated with abandoned mine sites vary widely and
are many. Table 21.1 lists components of mining operations, the risks or hazards that they
might present and the appropriate management measures to protect public safety.

Arguably the most important
factor in mine land rehabilitation
is the establishment and
maintenance of public safety.

21.3 FINANCING MINE CLOSURE - THE 'POLLUTER PAYS'
PRINCIPLE

A major disconnect in relation to mine closure is that much, if not all the costs involved,
are incurred after revenues from the project have ceased. Not surprisingly then govern-
ments have moved increasingly over the past decade towards securing adequate i nancial
provisions to deal with closure liabilities associated with mining operations. Estimation of
and provision for closure liabilities, of course, is also often a requirement for publicly listed
companies (e.g. to conform to the Sarbanes Oxely Act).
Closure liabilities vary widely and depend on type, size, complexity, and environmental
and regulatory setting of the mine. There is tremendous variation in mine deposits and
their ecological setting that may result in a wide range of complexities in mine and mill
design. This means that closure liabilities may range from US$ 1 million or less for a small
mine to US$ 100 million and more for old and large-scale mining operations (IFC 2002).
Governments frequently apply the 'polluter pays' principle and, to ensure that adequate
funding is available for closure, have applied a variety of different instruments of i nancial

Much, if not all the costs involved,
are incurred after revenues from
the project have ceased.