Investigating Groundwater Chemistry in the Coal Seam Gas Fields of the Surat Basin, Queensland, Australia

Large volumes of water must be pumped from coal seams in the Surat and Bowen basins in Queensland, Australia, in order to produce coal seam gas (CSG). Therefore, significant depletion of adjacent aquifers might be expected to occur. Management of the impacts of coal seam gas activities on groundwater therefore focuses on impacts on water levels. However, there is potential for groundwater quality impacts to occur in response to altered hydraulic gradients causing mixing between adjacent aquifers. While there have been previous studies of these processes in other countries such as the United States, there has been very limited research in this area in Australia.

A research project has been initiated at The University of Queensland to analyze groundwater chemistry data from coal seam gas fields across the Surat Basin. The data that has been used for this project has been obtained from the Queensland government and from CSG companies. Evaluation and interpretation of geochemical data is currently carried out in conjunction with stratigraphic interpretations. Preliminary results of these geochemical interpretations indicate that inclusion of trace elements in the analyses of basin-wide trends may improve our understanding of potential impacts of CSG activities on groundwater chemistry.