Quantifying the impacts of coal seam gas (CSG) activities on the soil resource of agricultural lands in Queensland, Australia

Coal seam gas (CSG) activities in the Surat and Bowen Basin areas of Queensland, Australia, cover approximately 300,000 km 2 including regions of good quality agricultural lands. Without adequate knowledge of soil properties, hydrologic processes and control measures, the disturbed soil structure and landform in these regions are highly susceptible to soil degradation. The construction and installation of CSG infrastructures (e.g. roads, pipelines, hardstand and plant areas) cause various degrees of disturbance to the soil physical, chemical and biological characteristics. This disturbance may result in soil degradation through various forms including compaction, erosion processes, changes to organic carbon and soil nutrient store, exposure of potentially reactive/poor quality soils (e.g. acid sulphate soils, hyper-saline soils) or introduction of outside contaminants (poor quality water, weeds). Not only are soils directly disturbed by the footprint of the CSG operation but the surrounding soil landscape may be disturbed by secondary processes such as erosion and sedimentation. Soil compaction changes caused by CSG operations, including vehicle impacts and trench line installation, have been assessed by soil bulk density measurements. This measurement has been identified as a common impact by CSG operation and a key element of soil degradation of agricultural areas contributing poor vegetation establishment, tunnel and surface erosion processes and an ongoing decline for soil productivity. Quantifying the impacts of CSG activities on soils will inform the development of industry guidelines for impact minimisation and management of the soil resource on joint CSG-agricultural lands.