SAFETY, HEALTH & ENVIRONMENT BULLETIN - MIRMgate

1 Introduction
Anglo American plc (AAplc) recognises that the long term success and acceptability of its business is
dependent upon good stewardship in the protection of the environment, and upon the efficient
management in the exploration and extraction of its mineral resources. Tailings disposal facilities,
waste rock dumps, discards and other residues represent some of the most significant environmental
risks associated with the mining industry and potentially involve third party liability.
Tailings disposal facilities are typically structures that are constructed in stages over many years and
there are usually several different parties involved from the original design and construction stage,
through operation and closure, to aftercare. The state of the facility continually changes, as do climatic
and other environmental factors. Problems that may develop can take a long time to manifest and
because the operators often change, these problems can be overlooked.
Tailings facility design and management requires a wide range of experience and expertise in many
disciplines and each stage of the life cycle has differing requirements. The person with the direct
responsibility for a tailings facility needs to involve a diverse team of experts in its management and
operation. Tailings and waste disposal is usually not a profit generator questionable practices are
sometimes accepted. Unfortunately the mining industry has continued to experience incidents relating
to failures and release of contaminants from tailings facilities.
The safety of tailings facilities is directly linked to the level of management of the facility. Poor
management has been identified as the principal underlying cause of most failures, even when the
design has been sound. For example a common reason for failures of tailings dams in the past has
been by overtopping. This is clearly a management shortcoming, rather than, for example, a less than
perfect understanding of the geotechnical and geochemical behaviour of the tailings by the consulting
engineering fraternity.
There exists a large volume of documentation relating to all aspects of design, construction, operation
and closure of tailings facilities in the form of manuals, technical papers, conference proceedings and
textbooks. There are also varying regulatory approaches in different countries, although none has
established a comprehensive set of laws and supporting regulations capable of addressing all aspects
of tailings design. There is an initiative in the International Council for Mining and Metals (ICMM) to
establish a web-based reference framework to facilitate access to this information and this is being
implemented at present. This is a step towards the possible development of an international guideline
for tailings management, although it is not envisaged that such a guideline will be available in the
immediate future.
The objective of this bulletin is to facilitate access to the relevant existing information by Group
companies, and to highlight the important aspects and critical areas where past experience has
indicated certain operations to have been lacking. As most of the facilities in the Group are in the
operational and closure phase, this bulletin is focused on those activities, rather than on the design or
construction phases where many other issues such as environmental impact assessments, site
selection, optimisation, etc. prevail.
2 The Design and Management Process for a Tailings Disposal Facility
The life cycle of a tailings disposal facility generally consists of the following elements:
• comparison of alternative disposal methods
• trade off studies and site selection
• optimisation and design
• construction of basic infrastructure and starter works (prior to tailings deposition)
• operation involving continuous expansion
• decommissioning and closure
• aftercare.
Generally the first four activities above are executed as part of a stand-alone project, whilst the latter
form an intimate part of the operation of a mine and are the responsibility of the operating staff.
Issued by the Anglo Technical Division page 4 of 47