St Ives, operated by Gold Fields, is one of the largest gold mines in the Eastern Goldfields region of Western Australia, having produced over 10.5 million ounces of gold since the mid-1980s. About 2 GL/a (60 L/s) of saline groundwater is used to supply a 4.5 Mtpa mill at Kambalda. The water is obtained from a borefield near Widgiemooltha, which draws from a major Tertiary palaeovalley sand aquifer. Over 50 GL have been extracted from the aquifer since 1991.
Rockwater designed and supervised two air-core exploration programmes in 2003 that led to the establishment of eight new production bores, mainly targeted to exploit groundwater mounds between existing bores.
We also regularly use a groundwater model to predict the capacity of the aquifer and provide advice on the pumping schemes needed to optimize the borefield’s longevity.
A TEMPEST airborne electromagnetic survey is being conducted to explore for extensions to the Mt Morgan aquifer and other palaeovalley aquifers in the region.
