Warrego Tailings Impoundment
Exploration of the Warrego copper-bismuth-gold anomaly commenced in the late 1950s and operated up to late 1989, producing approximately 4.94 Mt of ore. In addition to Warrego mine production, ores from other mines were trucked to the Warrego site for processing. They included ores from the White Devil, Gecko, Eldorado, and Orlando mines. In 1999, Normandy Tennant Creek Pty. Ltd. started developing closure strategies for their Warrego tailings storage facility.
Robertson GeoConsultants Inc. and O’Kane Consultants Inc. were retained to propose strategies for the rehabilitation of its Warrego tailings storage facilities (TSF). As part of Phase 1 of this investigation, the current impacts of tailings seepage on the local aquifer were evaluated and a groundwater flow and solute transport model was developed to predict future impacts for alternative closure scenarios. The groundwater flow model was calibrated using existing information on ground water levels and groundwater quality. The spatial extent of the contaminant plume was estimated using a solute transport model (MT3D).
Estimates of future seepage from the tailings facility for different cover scenarios were simulated using the soil-atmosphere model SoilCover. These estimates were used as input to the calibrated groundwater flow model to predict the time required for recovery of the groundwater system to pre-mining water levels for alternative cover scenarios. The Tennant Creek operations, including the Warrego TSF, were recently acquired by a local mining group and are still in operation today.
- Assessment of past and current impacts of tailings seepage on groundwater
- Development & Calibration of a 3D groundwater flow (MODFLOW)
- Development of a transport model to predict future impacts on groundwater (MODPATH & MT3D)
Normandy Mining Ltd. (now Newmont Asia Pacific)