Groundwater hydrochemical characterisation of the Surat Region and Laura Basin - Queensland

Background

A windmill near a paddock, with a background of lined trees and a cloudy sky

Windmill accessing shallow
groundwater, Surat Basin

The increase in coal seam gas (CSG) developments across many parts of eastern Australia during the past decade has led to widespread community concern about environmental and human health issues associated with the CSG industry. Of primary concern to many people are the potential impacts to water resources of CSG and large coal mining developments. Fundamental to better understanding these impacts is an understanding of groundwater systems and the processes that control them.

Geoscience Australia has undertaken a desktop study to investigate the potential for hydrochemical analysis to discriminate between groundwater in coal seams and adjacent aquifers in Queensland's Surat Region and Laura Basin. This study has collated and analysed existing groundwater chemistry data in the two areas. Analyses of the compiled hydrochemistry data involved a variety of methods aimed at characterising the groundwater chemistry present within particular hydrogeological units.

This project was commissioned by the Department of the Environment Office of Water Science.

Aims

This project aims to characterise the hydrogeochemistry of groundwater associated with coal seams and surrounding aquifers in the Surat Region and Laura Basin. The three objectives set to achieve the project aim are:

  1. Hydrochemical characterisation (ionic, organic, gaseous, radiogenic and stable isotopes) of groundwater within coal seams and adjacent aquifers to determine baseline conditions and, if possible, to distinguish between coal seam water and that of surrounding aquifers;
  2. Identification of knowledge and data gaps pertaining to CSG hydrogeochemistry; and
  3. Comparison of groundwater quality data to relevant water quality guidelines (ANZECC/ARMCANZ 2000; NHMRC/NRMMC 2011) to identify the environmental values of groundwater in relation to ecological and human use.

Two men standing near a paddock and a water tank with groundwater gas sampling equipment

Groundwater gas sampling in the Surat Basin

Outcomes

The key project outcomes will inform the Independent Expert Scientific Committee on Coal Seam Gas and Coal Mining (IESC) with regards to:

  1. the environmental values of groundwater and groundwater composition in coal seams and adjacent aquifers assessed for this study;
  2. the key data and knowledge gaps that limit current understanding; and
  3. targeting future investments (where appropriate) that will address the most critical knowledge gaps that exist in the Surat Region and Laura Basin.

Outputs

The following reports are available:

Final technical report: Groundwater Hydrochemical Characterisation of the Surat Region and Laura Basin - Queensland

Summary: Groundwater Hydrochemical Characterisation - Surat Region and Laura Basin, Queensland