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), 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
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.
BGMI (1991) Post Mining Geohydrology and Pit Closure. Report prepared in support of the Final Environmental
Impact Statement, Betze Project.
McDonald, M.G. and Harbaugh, A.W. (1988) A Modular Three-Dimensional Finite Difference Ground-water Flow
Model: U.S. Geological Survey Techniques of Water Resources Investigations, Book 6, Chapter A1, 586 p.
McDonald Morrissey Associates (1998) Regional Hydrologic Model. Report to BGMI dated February 24, 1998.
Radian International and Baker Consultants. 1997. Predicted Water Quality in the Betze-Screamer Pit Lake.
Final Report submitted to BGMI.
Parkhurst, D.L. and Appelo, C.A.J. (1999) User’s Guide To PHREEQC (Version 2)—A Computer Program For
Speciation, Batch-Reaction, One-Dimensional Transport, And Inverse Geochemical Calculations. Water-
Resources Investigations Report 99-4259. US Geological Survey.
Schafer, W.M., Logsdon, M., Zhan, G., and Espell, R. (2006) Post-Betze Pit Lake Water Quality Prediction. In 7th
ICARD, March 26-30, 2006, St. Louis MO.
Sobek, A.A., Schuller, W.A., Freeman, J.R., and Smith, R.M. (1978) Field and Laboratory Methods Applicable to
Overburdens and Minesoils. Report EPA-600/2-78-054, U.S. National Technical Information Report PB-
280495, 403 p.
Contaminant Risks and Off-Site Impacts
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