Mining often takes place in areas of complex hydrogeology, and there is a strong financial and environmental imperative to understand groundwater flow and geochemical processes.
NCGRT researchers have been working with mining companies for more than 10 years to understand the groundwater resources of the eastern Pilbara region. Because many of the open pit iron ore mines extend below the natural position of the water table, groundwater surrounding the mines is extracted to provide dry mining conditions. Significant volumes of surplus groundwater are being pumped every year, and some of this is discharged into rivers and creeks. NCGRT projects include examining the fate of surplus dewater that is discharged to the environment, and using geochemical approaches to estimate the proportion of discharge water that travels back to the pit necessitating additional dewatering. We have also been modelling the rate of pit lake development post mine-closure and the interaction between pit lakes and the groundwater system. We are also examining the potential of managed aquifer recharge to improve mine closure outcomes and assist the recovery of groundwater levels and rapid filling of pit voids post mine closure. These projects are also examining the influence of faults and dykes on groundwater flow, and their implications for mine dewatering and water table recovery post mine closure.
NCGRT also has significant expertise in geochemical processes that can lead to contamination of groundwater and surface water. Our researchers are examining both the processes controlling acid mine drainage, and contamination remediation options.
Sloan S, Cook PG and Wallis I (2023) Managed aquifer recharge in mining: A review. Groundwater, 61, 305-317. https://doi.org/10.1111/gwat.13311.
Chen Q, Cohen DR, Andersen MS, Robertson AM and Jones D (2022) Stability and trace element composition of natural schwertmannite precipitated from acid mine drainage. Applied Geochemistry, 143, 1-12. https://doi.org/10.1016/j.apgeochem.2022.105370.
Bozan C, Wallis I, Cook PG and Dogramaci S (2022) Groundwater level recovery following closure of open pit mines. Hydrogeology Journal, 30, 1819-1832. https://doi.org/10.1007/s10040-022-02508-2.
Baublys K A, Hofmann H, Esterle JS, Cendón DI, Vink S, and Golding SD (2021) Geochemical influences on methanogenic groundwater from a low rank coal seam gas reservoir: Walloon Subgroup, Surat Basin. International Journal of Coal Geology, 246, 103841. https://doi.org/10.1016/j.coal.2021.103841.
McIntyre N, Jain KR, and Edraki M (2021) Modelling of salt leaching from coal mine spoils at two scales. Mine Water and the Environment, 40, 902-918. https://doi.org/10.1007/s10230-021-00797-9.
Cook PG, Dogramaci S, McCallum J and Hedley J (2016) Groundwater age, mixing and flow rates in the vicinity of large open pit mines, Pilbara region, northwestern Australia. Hydrogeology Journal, 25, 39-53. https://doi.org/10.1007/s10040-016-1467-y.