Contamination assessment of mine infrastructure areas for closure and relinquishment: Hazelwood Coal Mine, Victoria, Australia

Authors: Weaver, TR; Fridell, PS; Ospina, MB; Brooker, R; Schenkel, MK; Scrase, AM Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_rep/1915_116_Weaver

Cite As:
Weaver, TR, Fridell, PS, Ospina, MB, Brooker, R, Schenkel, MK & Scrase, AM 2019, 'Contamination assessment of mine infrastructure areas for closure and relinquishment: Hazelwood Coal Mine, Victoria, Australia', in AB Fourie & M Tibbett (eds), Mine Closure 2019: Proceedings of the 13th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1491-1496, https://doi.org/10.36487/ACG_rep/1915_116_Weaver



Abstract:
The Hazelwood coal mine and power station, near Morwell in the Latrobe Valley, Victoria, ceased operation in March 2017. A water filled mine void with potential for recreational, agricultural, commercial and industrial uses is envisioned for the surrounding area following mine licence relinquishment. Critical to achieving this is the assessment and management of infrastructure and potential contamination that is present in the mine licence area. This paper presents the approach to this assessment so that land management options and, if necessary, remediation can be identified and implemented early in the rehabilitation project. In Victoria, the Environmental Protection Agency (EPA) is the lead agency for land and water pollution; Department of Jobs, Precincts and Regions (DJPR) leads the mine rehabilitation process. These processes run in parallel, influencing each other. For the mine void the owner, ENGIE, has implemented a strategy that is consistent with EPA requirements, removing most equipment whilst leaving some in place. Infrastructure surrounding the mine, including conveyors, ash and water pipelines, and lay-down yards is being addressed through principles aligning with the National Environment Protection (Assessment of Site Contamination) Measure (ASC NEPM) contaminated site assessment approach, in parallel with mine closure and rehabilitation requirements. A preliminary site investigation (PSI) is underway that is based on former operational and sub-catchment areas and which includes a comprehensive history of former site activities and environmental condition. A key challenge at Hazelwood is the scale. The pit perimeter is over 16 km and the mine license area exceeds 1,200 ha. Former activities in and around the mine include: coal and coal ash handling; coal ash, hard rubbish and asbestos disposal; fuel storage and handling; pipe works, and surrounding commercial, industrial, and agricultural activities. The PSI will identify the likely level of contamination so that some areas may be able to be excised from further works while others move to detailed site investigation (DSI) and, if necessary, remediation. A sub-catchment approach to sub-areas allows source-pathway-receptor conceptual site models to be developed that are consistent with the NEPM regardless of whether areas progress to DSI and remediation stages, or are closed out at PSI stage.

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