Sinclair, EJP & Weber, P 2022, 'Good acid and metalliferous drainage management begins well before mine closure: a New Zealand example', in AB Fourie, M Tibbett & G Boggs (eds), Mine Closure 2022: 15th International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 375-388, https://doi.org/10.36487/ACG_repo/2215_25
Bathurst Coal Limited (Bathurst) owns and operates the Canterbury Coal Mine (the Mine), Canterbury New Zealand. The Mine was purchased in 2013, and during acquisition, it was identified that there were legacy issues associated with acid and metalliferous drainage (AMD).
After operational activities started at the site, under the direction of Bathurst, a strategic approach to AMD management was undertaken to address this legacy AMD and also future potential issues. This included a staged response to characterise and schedule materials, assess AMD risks, and implement appropriate engineering controls (prevention minimisation, control and treat) to address these risks. This led to a significant reduction in AMD effects including an improvement in pH and a reduction in acidity loads for the site.
When market and social license issues resulted in the decision to close the Mine in early 2021, the site was well placed to transition to mine closure.
This paper covers the steps undertaken during the operation of the Mine to resolve the legacy AMD issues and minimise AMD impacts associated with ongoing operational activities such that a robust best practicable mine closure plan was possible that will ensure good long-term environmental outcomes with minimal active management requirements.
Keywords: acid and metalliferous drainage, mine closure, prediction, prevention, legacy, adaptive management
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