Alcoa Anglesea Mine Closure - Independent Technical Review
The proposed closure of the Anglesea Coal Mine involves diversion of a local creek system to fill an open cut void. The void will form a water body that will have controlled overflow to the down-stream Anglesea River system.
Coal from the mine fed the adjacent closed Alcoa Anglesea Power Station which had associated soil and groundwater contamination issues. The mine pit is below the regional water table and the underlying and surrounding geology contains a complex aquifer system (comprising multiple aquifers), including one which provides a potable water supply to the regional water authority.
BlueSphere’s scope of work included the completion of an independent peer review of specific elements of the overall Mine Closure Plan. This comprised critical review of hydrological, hydrogeological and geochemical studies, including those related to the creek diversion from and back to the natural surface water system.
Local acidic conditions in the catchment and those related to acid mine drainage created a substantial challenge to the maintenance of acceptable water quality. In particular, it needed to be adequately demonstrated that the quality of the water body that would fill the mine pit and ultimately be released would be sufficient to avoid unacceptable impact on the down-stream environment.
BlueSphere assembled a team of national and international experts (internal and external to BlueSphere) including a geochemist, hydrogeologists, a limnologist, a numerical groundwater modeller and hydrologist to review a wide range of detailed and complex technical studies and attended various meetings and a workshop to resolve major issues. The team brought an extensive mining background to the project, in particular substantial experience and expertise with acid mine drainage and mine water body geochemistry and hydrodynamics.
An Independent Technical Peer Review report was produced for inclusion in the Mine Closure Plan being submitted to the regulator (Earth Resources – Department of Economic Development, Jobs, Transport and Resources).
Benefits to Client
- A substantially improved Mine Closure Plan in terms of structure, general quality and technical range, depth and rigour meaning a higher chance of approval.
- The gravity of endorsement from a very high calibre independent team of experts to support the approval process.
- Improved clarity for Alcoa on the likely challenges and risks of mine closure to assist in its planning and assistance in ensuring that project is practically achievable.
- Reduction in a broad range of project risks.