Basin-wide groundwater vulnerability assessment: a GIS based DRASTIC approach to the problem of coal seam gas extracted water

Abstract

Coal seam gas (CSG) production requires the extraction of large volumes of water. Discharges of the extracted water into the environment occur via authorised temporary permits or through accidental releases. The purpose of this study is to assess the risk to shallow groundwater aquifers from potential CSG water releases in Queensland, Australia. A GIS based methodology was used to identify vulnerable shallow aquifers by overlaying a series of risk factors, which increase the likelihood of flow from the ground surface into aquifers below. We identified where the vulnerable aquifers are located and estimate that about 10,000 people live in these areas. The GIS based exposure mapping approach applied here provides a useful ‘first-pass’ assessment of areas with CSG activity. Areas identified as potentially high risk should be prioritised for further detailed investigation.

Keywords

• coal seam gas water
• groundwater contamination
• GIS
• DRASTIC
• Queensland