Closure Pit Lake Water Management Options, Betze-Post Pit, Nevada, USA

Authors: Schafer, W; Logsdon, M; Zhan, G; Espell, R Paper is not available for download Contact Us

DOI https://doi.org/10.36487/ACG_repo/605_53

Cite As:
Schafer, W, Logsdon, M, Zhan, G & Espell, R 2006, 'Closure Pit Lake Water Management Options, Betze-Post Pit, Nevada, USA', in AB Fourie & M Tibbett (eds), Mine Closure 2006: Proceedings of the First International Seminar on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 613-621, https://doi.org/10.36487/ACG_repo/605_53



Abstract:
The Barrick Goldstrike Mine Inc. (BGMI) is located in the Carlin Trend, about 32 km northwest of Carlin, Nevada, USA. The majority of the ore mined at BGMI is from the Betze-Post open pit, the largest open pit operation in Nevada. Although mining is anticipated to continue at least through 2014 at BGMI, post- closure pit lake recovery rates and water quality have been predicted using hydrologic and geochemical models in order to design for optimum closure of the facility. Pit lake studies at BGMI found that the pit lake would have no surface water or groundwater outflow. Therefore, owing to the semi-arid environment, continued net-evaporation from the lake surface would be expected to cause long-term increases in salinity. This study evaluated the effect of removing water seasonally for irrigation use when the pit nears its equilibrium level. Additionally, the effects of placing 516 Mt of backfill waste rock into the open pit were also examined. The pit lake is predicted to contain water that is suitable for irrigation. Additionally, withdrawal of even a small amount of water was predicted to significantly improve long-term water quality by breaking the evapo-concentration cycle.

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