Barrick Open-Pit Gold Mine
Barrick Goldstrike Mines Inc. owns and operates the largest open-pit gold mine in North America northwest of Carlin, Nevada. Nearby, Barrick also operates an underground gold mine. The groundwater flow system is in fractured and solutioned carbonate rocks, fractured volcanic rocks and alluvium. Groundwater levels must be lowered about 1,600 feet below pre-mining levels to keep the two mines dry for mining. Barrick developed a groundwater flow model prior to the start of pumping and has re-calibrated the model each year as new data were acquired. Currently, the model is used to establish pumping rates for the desired amount of water-level lowering at the mines, management of pumped water and possible depletion of base flow of nearby mountain streams.
MMA prepared a report on the conceptual model of the groundwater flow system, conducted a technical review of the existing model made recommendations for model testing, evaluation, improvement and documentation.