Authors: Warrender, R; Prestia, A; Bowell, RJ; Byrns, C; Rakvica, B; Spidell, J


Cite As:
Warrender, R, Prestia, A, Bowell, RJ, Byrns, C, Rakvica, B & Spidell, J 2013, 'Defining an approach for contaminated land management in the context of mine reclamation in the historic Comstock mining district, Nevada, USA', in M Tibbett, AB Fourie & C Digby (eds), Mine Closure 2013: Proceedings of the Eighth International Seminar on Mine Closure, Australian Centre for Geomechanics, Cornwall, pp. 55-68,

Download citation as:   ris   bibtex   endnote   text   Zotero

Many abandoned mine sites are characterised by elevated concentrations of environmentally sensitive elements such as arsenic, lead and mercury that can cause contamination of surrounding soil and water resources and may have associated ecological and health impacts. Often these sites have important historic and cultural values that require access to be maintained, despite potential toxicity of the waste. Detailed site characterisation is therefore essential to ensure implementation of appropriate management measures and prevent potential impact to receptors. This paper presents an approach to evaluating potential environmental impacts in a historically important mining district, the Comstock gold and silver mining district in Nevada, USA. For this site, geochemical soil surveys demonstrate elevated levels of arsenic, lead and mercury that are influenced by anomalous geological background concentrations connected to bedrock mineralisation, placement of mineralised waste rock and element redistribution around sites of mineral processing. The goal of the data evaluation is to develop screening levels against which geochemical data could be compared and classified for purposes of management of the materials on-site. A common approach for contaminated land is the application of normal probability plots. However, where materials have been influenced by different processes (e.g., hydrothermal mineralisation, supergene weathering, mining and processing), the inherent differences in these materials may mask or overshadow geochemical anomalies and such an approach is flawed. In order to compensate for these differences, a site-specific mineralogical and uni-variant statistical approach has been applied. This approach can be used as an initial (Tier 1) screening tool to isolate undisturbed mineralised outcrop from disturbed areas or mine waste. Further evaluation of the geochemical data can then be undertaken as part of a Tier 2 assessment, including an assessment of contaminant bioavailability and leachability using selective extraction and physiologically based extraction tests. A Tier 3 assess would then involve the employment of geochemical predictive calculations to determine the potential of contaminants to disseminate in the environment. In this way, the areas demarked as having potential to impact the environment and interact with a receptor can be identified and appropriate management strategies implemented. This approach has the benefit of controlling costs and protecting the cultural value of historic mining areas while still allowing protection of the environment and mitigation of potential future environmental impacts.

Anthony, J.W., Bideaux, R.A., Bladh, K.W. and Nichols, M.C. (2013) Handbook of Mineralogy, Mineralogical Society of America, Chantilly, Va.
Bonham, H.F. (1969) Geology and Mineral Deposits of Washoe and Storey Counties, Nevada, Nevada Bureau of Mines and Geology, Bulletin, 70 p.
Bowell, R.J. (1994) Sorption of arsenic by iron oxides and oxyhydroxides in soil, Applied Geochemistry, Vol. 9, pp. 279–286.
Bowell, R.J., Rees, S.B., Barnes, A., Prestia, A., Warrender, R. and Dey, B.M. (2013) Geochemical assessment of arsenic toxicity in mine site along the proposed Mineral Tramway Project, Camborne, Cornwall, Geochemistry, Exploration, Environment and Analysis, Vol. 13(2), in press.
Cathro, R.J. (2008) The Comstock Lode, Nevada, CIM Magazine, Vol. 3(4), pp. 61–76.
Fehling Group (2012) In Vitro Bioaccessibility Study for Arsenic and Lead, Reno, Nevada.
Frau, F., Ardau, C. and Fanfani, L. (2009) Environmental geochemistry and mineralogy of lead at the old mine area of Baccu Locci (south-east Sardinia, Italy), Journal of Geochemical Exploration, Vol. 100, pp. 105–115.
Gardner, P.S. and Carpenter, J.A. (1935) Present Day Milling Plants on the Comstock Lode, viewed 26 July 2012,
González, J.C.A., Cala Rivero, V. and Iribarren Campaña, I. (2012) Geochemistry and mineralogy of surface pyritic tailings impoundments at two mining sites of the Iberian Pyrite Belt (SW Spain), Environmental Earth Sciences, Vol. 65, pp. 669–680.
Hedenquist, J.W., Aribas, A.R. and Golzalez-Urien, E. (2000) Exploration for epithermal gold deposits, Reviews in Economic Geology, Vol. 13, pp. 245–277.
Hudson, D.M. (2003) Epithermal alteration and mineralisation in the Comstock District, Nevada, Economic Geology, Vol. 98, pp. 367–385.
Kim, C.S., Rytuba, J.J. and Brown, Jr., G.E. (2004) Geological and anthropogenic factors influencing mercury speciation in mine wastes: an EXAFS spectroscopy study, Applied Geochemistry, Vol. 19, pp. 379–393.
Lottermoser, B. (2003) Mine Waste: Characterisation, Treatment, and Environmental Impacts, Springer, 277 p.
Mason, B. (1966) Principles of Geochemistry, 3rd edition, John Wiley, New York, 220 p.
Ruby, M.V., Schoof, R., Brattin, W., Goldade, M., Post, G., Harnois, M., Mosby, D.E., Casteel, S.W., Berti, W., Carpenter, M., Edwards, D., Cragin, D. and Chappell, W. (1999) Advances in evaluating the oral bioavailability of inorganics in soil for use in human health risk assessment, Environmental Science and Technology, Vol. 33, pp. 3,697–3,705.
Rytuba, J. (2005) Geologic and mining sources of mercury to the environment, in Mercury: Sources, Measurements, Cycles and Effects, M.B. Parsons and J.B. Percival (eds), MAC Short Course, Vol. 34, pp. 21–42.
Singh, A.K., Singh, A. and Engelhardt, M. (1997) The Lognormal Distribution in Environmental Applications. U.S. Environmental Protection Agency, Office of Research and Development.
Sladek, C. and Gustin, M.S. (2003) Evaluation of sequential and selective extraction methods for determination of mercury speciation and mobility in mine waste, Applied Geochemistry, Vol. 18, pp. 567–576.
Smith, G.H. (1943) The History of the Comstock Lode 1850–1920, Nevada Bureau of Mines Bulletin 37, 305 p.
Smith, G.H. and Tingley, J.V. (1998) The History of the Comstock Lode 1850–1997, 328 p.
SRK (2012) Relationship of Mercury, Lead and Arsenic in the South Comstock Mineral District, prepared for Comstock Mining Inc.
Stoddard, C., and Carpenter, J.A. (1950) Mineral Resources of Storey and Lyon Counties, Nevada, Geology and Mining Series No. 49, Nevada Bureau of Mines and Geology and University of Nevada Press, Reno and Las Vegas.
Tidball, R.R., Briggs, P.H., Stewart, K.C., Vaughn, R.B. and Welsch, E.P. (1991) Analytical data for soil and well core samples from the Carson River Basin, Lyon and Churchill Counties, Nevada, U.S. Geological Survey, 47 p.
USEPA (United States Environmental Protection Agency) (1990) Reducing Risk: Setting Priorities and Strategies for Environmental Protection, Science Advisory Board.
USEPA (United States Environmental Protection Agency) (1995) Record of Decision, Carson River Mercury Site, Operable Unit 1L Surface Soil.
USEPA (United States Environmental Protection Agency) (2003) Recommendations of the Technical Review Workgroup for Lead for an Approach to Assessing Risks Associated with Adult Exposures to Lead in Soil, Final (December 1996).
USEPA (United States Environmental Protection Agency) (2012) Integrated Risk Information System, .

© Copyright 2021, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
Please direct any queries or error reports to