RPS worked with PolyMetals and Exco to develop a water supply for the White Dam Gold Project, located in the arid far north of South Australia, about 100 km east of Broken Hill.
The October 2005 work involved a water supply options study, in partnership with consultants REM, to prioritise targets for drilling and testing in the fractured bedrock aquifer at the site, and in the Yarramba palaeochannel (about 20 km up-gradient from Honeymoon). The options study used available geological mapping, bore drilling and groundwater monitoring database information, plus interpretations of airborne geophysical (gravity, TMI and radiometric) data from Exco and SA Government agencies (SAGeodata, DWLBC ObsWell, PIRSA Spatial Information).
An existing bore near the White Dam site was test pumped by RPS in 2005, with results confirming the potential for the local fractured bedrock aquifer to provide an adequate water supply for the proposed heap leach mining operation. Subsequent detailed analysis of Exco’s geophysical data and mineral exploration drilling logs was used to plan the staged investigation program of further drilling and testing for a pilot water supply investigation. Stage 1 of the pilot trial was successful in 2006, with subsequent successful completion of four bores to provide up to 45 L/s from the local fractured rock aquifer in 2007 and 2008. A conceptual design for the local aquifer water supply pumping and pipeline system was prepared and costed by RPS.
Previously, in 2005-2006, the Yarramba palaeochannel was investigated as a backup water supply source by RPS in partnership with REM. The investigations involved ground-based gravity surveys and interpretations to identify specific targets that were then drilled and test pumped. The palaeochannel bore targets were used as the basis for RPS to complete a conceptual design for a 40 km pipeline and pumping system from the palaeochannel, prepare feasibility level cost estimates, and assist Exco with pipeline route inspections and access reviews. This became a backup option that was not invoked. The hydrogeological and engineering investigations were used to develop a sustainable water management strategy and monitoring program to support the project.