McLeary, MB 2009, 'Striving for ‘walk-away’ — focusing an expert group on the ‘holy grail’ of mine closure', in AB Fourie & M Tibbett (eds), Mine Closure 2009: Proceedings of the Fourth International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 359-373, https://doi.org/10.36487/ACG_repo/908_27
Leading practice ‘mine closure’ is now integral to mine planning from inception. However, in an historic
site there is limited opportunity to gain site knowledge and integrate closure planning throughout the life of
the mine. Acid metalliferous drainage (AMD) at Brukunga Mine, 90 minutes east of Adelaide, South
Australia, is a significant long-term environmental issue as a consequence of pyrite mining – with the site
now comprising two large waste rock dumps, a tailings dam, mine benches and voids, all containing
sulphidic material. Past and current predictions are that generation of AMD could require ongoing
treatment for 300 to 1,000 years. The South Australian Government has managed this site since 1977 and
costs are approximately A$1 m per annum. The Department of Primary Industries and Resources South
Australia (PIRSA) is currently implementing a process for determining the most effective long-term solution
for site remediation.
A review of the current mine management strategy was undertaken in 2007, resulting in the development of
the Brukunga Mine Forward Program, comprising six phases. Phase 1 included the establishment of a
technical advisory group (TAG), tasked with recommending (to Government) the most effective technical
‘walk-away’ remediation solution for Brukunga Mine. The TAG provides some 125 years of combined
national and international experience specialising in geochemistry and water treatment; geotechnical
aspects and soil covers; and remediation options and costing1. The group developed potential ‘walk-away’
remediation solutions by functioning under a guided self-management model. This model incorporated
shared information, shared decision-making, application of selected expertise across different
companies/agencies, and group developed models to generate creative and holistic solutions to complex
problems. The TAG operated independently but under overarching guidance applying a variety of
technologies and process strategies including meeting in workshops, online, on-site and in teleconference
environments at frequent intervals.
Validation of the TAG process and guided self management model, is demonstrated by an agreed notion that
‘walk-away’ remediation is realistic and achievable, by delivering a preferred ‘walk-away’ remediation
option to Government and thereby ensuring commencement of Phase 2 (testing, feasibility of the option) of
the Forward Program. The focus of this paper is to illustrate the process by which the TAG functioned and
developed such a ‘walk-away’ solution at Brukunga Mine. Ultimately, committing to and implementing any
‘walk-away’ remediation of AMD at Brukunga Mine rests with future Government.
Australian Nuclear Science and Technology Organisation (ANSTO) (1994) Oxidation rates in waste rock dumps and
the tailings dam at Brukunga: A report to Environmental Geochemistry International Pty Ltd, ANSTO/C384,
Sydney, Internal Report (unpublished).
Department of Industry Tourism and Resources (DITR) (2006) Mine Closure and Completion: Leading Practice
Sustainable Development Program for the Mining Industry, Australian Government Department of Industry
Tourism and Resources, Commonwealth of Australia, Canberra.
Environment Australia (EA) (1999) Environmental Risk Management: Best Practice Environmental Management in
Mining, June, Environment Protection Agency, Canberra, p. 9.
Primary Industries and Resources of South Australia (PIRSA) (2001) Brukunga Mine Site Rehabilitation Rock Dump
Relocation, Primary Industries and Resources of South Australia, South Australian Government, Adelaide,