Cline, DJ, Crouse, PE, DeDen, FM & Zimmer, TR 2016, 'Engineering and reclamation of the Holden Legacy Mine — advancing the state-of-practice for mine closure', in AB Fourie & M Tibbett (eds), Mine Closure 2016: Proceedings of the 11th International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 389-404, https://doi.org/10.36487/ACG_rep/1608_28_Cline
Rio Tinto is reclaiming an abandoned copper mine in one of the most isolated places in the continental U.S., located near Lake Chelan in the remote reaches of north-central Washington State. The Holden Mine was one of the largest operating underground copper mines in the U.S.; the mine was developed and operated between 1937 and 1957 and produced over 90,000 tonnes of copper, as well as zinc, silver and gold. Over the life of the mine, nearly 100 km of underground tunnels had been excavated and 7.6 million tonnes of mill tailings placed on U.S. National Forest lands near Railroad Creek. Although Rio Tinto never owned or operated the mine, they are managing and funding a several hundred million dollar clean-up to prevent future water and soil contamination and to restore the former mine site under the United States Environmental Protection Agency Superfund process. Adjacent to the mine is a former man camp, now home of the Holden Village Inc., a religious community that hosts 5,000 to 6,000 visitors each year. Engineering the Holden Mine remedial design required development of an integrated system of mine closure components including: infrastructure improvements, surface water and sediment management, slope stability improvements, surface and groundwater collection and treatment, mill demolition, and restoration to re-establish vegetation consistent with that of the surrounding forest. This paper addresses these topics and includes information on the design criteria and objectives, pre-design investigations and evaluations, and a summary of the design for each remedial component. The paper concludes with the project successes and lessons learned from engineering the remedial design. The first in a series of technical papers, this paper provides the mine closure community an overview of the innovative design and construction techniques that have been applied at the Holden Mine with the goal of further advancing the state-of-practice for mine closure and remediation at other sites.
Keywords: legacy, reclamation, remediation, design, case study
Cline, D, Stevens, C, Paulson, E, Crouse, P & Gargeya, D 2012, ‘Guidance on Estimating Peak Flood Flow Frequency in Ungauged Watersheds’, Proceedings of Mine Closure 2012, Australian Centre for Geomechanics, Perth pp. 785–799.
Idriss, I & Boulanger, R 2008, Soil Liquefaction During Earthquake, EERI monograph MNO-12.
MWH 2014, Remedial Design Report for Post-2012 Phase 1, Final (100 Percent), August 1, 2014.
USDA FS (United States Department of Agriculture & U.S. Forest Service) 2012, Record of Decision, Holden Mine Site, Chelan County Washington, January 27, 2012.
USACE (U.S. Army Corps of Engineers) 1998, Runoff from Snowmelt, Engineer Manual 1110-2-1406, March 1998.
Wang, ZF, Shen, SL, Ho, CE & Kim, YH 2013, ‘Jet Grouting: an Overview’, Geotechnical Engineering Journal of the SEAGS & AGSSEA, vol. 44 No. 4, December.
Youd, TL & Idriss, IM 2001, ‘Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/SF Workshops on Evaluation of Liquefaction Resistance of Soils’, Journal of Geotechnical and Geoenvironmental Engineering, vol. 127, No. 10, pp. 817–833.
Zanadvoroff, VA 1946, ‘Disposal of Mill Tailings at the Holden Concentrator’, A.I.M.E. Transactions, vol. 169, pp. 686–693.