Tailings Disposal - Mining and the Environment: From Ore to Metal - page 747

Australia, dei ne standards for routine inspections and operational audits. A comple-
mentary document is 'Tailings Dam HIF Audit' that describes the components of an
independent audit according to the Australian standards (notesweb.mpr.wa.gov.au).

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The Canadian guidelines 'A Guide to the Management of Tailings Facilities' and
'Developing an Operation, Maintenance and Surveillance Manual for Tailings and
Water Management' both produced by the Mining Association of Canada suggest that
periodic inspections and reviews, audits, independent checks and comprehensive inde-
pendent reviews need to be carried out as part of the surveillance programme. The
documents can be found at www.mining.ca .

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The primary document controlling a mining company's tailings disposal activities in
South Africa is the Department of Mineral and Energy Mandatory Code of Practice
for Mine Residue Deposits (MRDs) (available on the website www.dme.gov.za ). This
code requires every mine to set out in writing its intended standards and procedures
for the protection of the health and safety of workers, and for the reduction of the risk
of damage to persons and property.

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In Sweden, generally all mining companies need to implement programmes for daily,
monthly and yearly inspections/audits, but there are no requirements on independent
audits.

Closure

In recent years, there have been a number of studies to consider the standards to be
achieved on closure in USA, Canada, Australia, and, most recently, in Europe (Xenidis
2004.). Generally, the major issues to be considered for the reclamation of mining/
milling components include the long-term (1) physical stability, (2) chemical stability and
(3) land use. Based on regulations developed in Canada (Doran and McIntosh 1995), after
closure, mine waste storage facilities should be physically stable under extreme events
such as l oods, earthquakes and perpetual disruptive forces including wind and water ero-
sion, so that they do not impose a hazard to public health and safety or the environment.
Regarding chemical stability, leaching of contaminants contained in mine wastes and
migration into the environment should not endanger public health or safety, nor exceed
water quality objectives in downstream watercourses. Based on the guidelines prepared by
the Department of Minerals and Energy, Western Australia (DME 1999), decommissioned
tailings storage facilities must be safe, stable and aesthetically acceptable. Some fundamen-
tal mine closure design criteria, based on MIRO (1999) are given in Table 18.7 .
The ultimate land use of any tailings storage should be determined, ideally at the outset,
but dei nitely long before tailings discharge ceases. As mentioned previously, rehabilita-
tion to a sustainable, economically productive land use may be a critical factor in maintain-
ing the long-term integrity of the tailings storage. However, there will be some instances
where government policies or compelling ecological factors dictate that the tailings storage
should be rehabilitated with local native vegetation.
Selection of the preferred land use may be obvious; more often, however, it will involve
a somewhat lengthy process, including: (1) consultations with existing and potential stake-
holders including land owners, ultimate land users if known, local communities and gov-
ernment authorities; (2) detailed assessment and consideration of land capabilities under a
range of different rehabilitation strategies; (3) review of agricultural, horticultural, aqua-
cultural and forestry products and practices in the region, with screening to assess which are
potentially applicable to the tailings storage; (4) conduct of i eld trials to establish the feasi-
bility of growing various crops, with or without various cappings, cultivation treatments,

The ultimate land use of any
tailings storage should be
determined, ideally at the outset,
but defi nitely long before tailings
discharge ceases.