Interim Independent Expert Scientific Committee on Coal Seam gas and Coal Mining

Aquifers - taking into account both aquifer contamination and aquifer integrity

Coal seam gas extraction poses a potential risk of interconnectivity between aquifers with possible consequences for fresh water aquifers both in terms of quantity and quality. Changing interconnectivity between aquifers potentially can have serious implications for surface water resources. Large coal mines can affect water flow through river diversions and flood protection works. Dewatering of the mine can also disrupt groundwater flow patterns. Areas of research are focused on the water balance, bore integrity, fraccing, reinjection, subsidence, disruption of surface and groundwater flow pathways, mine site remediation, and cumulative impacts.

Project Title Project Description
Critical science review -
bore integrity
Bore construction, integrity, monitoring and reporting, and decommissioning techniques.
Critical science review -
subsidence
Predicting, monitoring, assessing, and remediating subsidence related impacts associated with coal seam gas and coal mining activities.
Critical science review -
cumulative and strategic assessment modelling
Review of current literature associated with cumulative and strategic impact assessment techniques, including modelling groundwater impacts and co-produced water.
Critical science review -
aquifer connectivity
Define aquifer connectivity and relevance to the impact of coal seam gas and coal mining on water resources. Aquifer connectivity will be discussed from a geometric and hydraulic viewpoint.
Monitoring and managing bore integrity -
non Lake Eyre
This project seeks to reduce the potential risk of aquifer leakage by improving the integrity and monitoring of existing and discontinued coal seam gas and agricultural bores. This will be achieved through the identification of priority areas for investigating bore integrity; the identification of priority bores requiring examination; and an evaluation of bore monitoring and investigation approaches.
Subsidence impact of aquifer drawdown due to underground longwall coal mining activities This project aims to improve understanding of the critical issue of subsidence induced by longwall coal mining, and its consequent effects on water systems and on land use.
Subsidence impact of aquifer drawdown due to coal seam gas extraction This project aims to improve understanding of the critical issue of subsidence induced by coal seam gas extraction, and its consequent effects on water systems and on land use.
Comparison of groundwater modelling approaches This project will research existing groundwater models and the capacity of the models to predict impacts of coal seam gas production.
Hydraulic properties of aquifer geology Establish the hydraulic properties, such as porosity and permeability, of rock types common to coal seam gas mining in order to be able to predict the effects of depressurisation induced by the extraction of gas. Determine the potential leakage characteristics of different geological formations.
Regional hydrogeological characterisation - for the regions not covered in the five initial priority bioregions (announced by the Minister in March 2012 for bioregional assessments - Coal seam gas expert scientific committee legislation introduced ) Multidisciplinary characterisation of the detailed geology and hydrostratigraphy of those coal basins intended to cover the Laura, Maryborough, Otway and St Vincent Basins.