Skip to main content

Legacy Arsenic Pollution of Lakes Near Cobalt, Ontario, Canada: Arsenic in Lake Water and Sediment Remains Elevated Nearly a Century After Mining Activity Has Ceased


Century old mine tailings in the Cobalt and Silver Center areas are widely dispersed throughout the terrestrial and aquatic environments and contain high concentrations of arsenic. Arsenic concentrations were found to be as high as 972 μg/L in surface waters and 10,800 mg/kg in lake sediment. The mean values for arsenic in surface waters and sediment from 9 lakes directly influenced by mining activity were 431 μg/L and 1704 mg/kg, respectively, whereas in the 12 control lakes with no mining activity in their catchment had mean values of 2.2 μg/L and 11 mg/kg in their water and sediment, respectively. Lakes impacted by downstream tailing migration (n = 4) were also assessed and had intermediate concentrations of arsenic. Principal component analysis identified contaminated lakes as having different geochemical signatures than control lakes but lake sediment that was sampled below tailings in contaminated lakes, deposited pre-mining, can resemble the geochemistry of those found in control lakes. Arsenic concentrations in these samples ranged from 4.4 to 185 mg/kg, which can be considered reasonable background as these areas contained abundant mineral deposits that could naturally elevate background concentrations. Even though background concentrations are naturally elevated, the presence of arsenic-rich tailings in these lakes has prevented any natural recovery from occurring. Fe-Mn oxides at the water-sediment interface perpetually scavenge arsenic from buried tailings below and from contaminated surface waters that cause arsenic concentrations to remain enriched in the upper sediments even after tailings have been buried by lake sediment. This process has prevented recovery of the lake ecosystems even after nearly a century without mining.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7


  • Andrade, C. F., Jamieson, H. E., Kyser, T. K., Praharaj, T., & Fortin, D. (2010). Biogeochemical redox cycling of arsenic in mine-impacted lake sediments and co-existing pore waters near Giant Mine, Yellowknife Bay, Canada. Applied Geochemistry.

  • Andrews, A. J., Owsiaki, L., Kerrich, R., & Strong, D. F. (1986). The silver deposits at Cobalt and Gowganda, Ontario: geology, petrography and whole-rock geochemistry. Canadian Journal of Earth Sciences., 23, 1480–1506.

    Article  CAS  Google Scholar 

  • Blais, J. M., & Klaff, J. (1995). The influence of lake morphometry on sediment focusing. Limnology and Oceanography, 40.

  • Borvůka, L., Vacek, O., & Jehlička, J. (2005). Principal component analysis as a tool to indicate the origin of potentially toxic elements in soils. Geoderma.

  • Bowell, R. J. (1994). Sorption of arsenic by iron oxides and oxyhydroxides in soils. Applied Geochemistry, 9, 279–286.

    Article  CAS  Google Scholar 

  • Boyle, R.W. (1968). The geochemistry of silver and its deposits, with notes on geochemical prospecting for the element. Geological Survey of Canada, Bulletin 160.

  • Canadian Council of Ministers of the Environment. (1999). Canadian sediment quality guidelines for the protection of aquatic life: Arsenic. In: Canadian environmental quality guidelines, 1999, Canadian Council of Ministers of the Environment, Winnipeg.

  • Canadian Council of Ministers of the Environment. (2001). Canadian water quality guidelines for the protection of aquatic life: Arsenic. Updated. In: Canadian environmental quality guidelines, 1999, Canadian Council of Ministers of the Environment, Winnipeg.

  • Cheng, Q., Bonham-Carter, G. F., Hall, G. E. M., & Bajc, A. (1997). Statistical study of trace elements in the soluble organic and amorphous Fe-Mn phases of surficial sediments, Sudbury Basin. 1. Multivariate and spatial analysis. Journal of Geochemical Exploration., 59, 27–46.

    Article  CAS  Google Scholar 

  • Couture, R. M., Gobeil, C., & Tessier, A. (2010). Arsenic, iron and sulfur co-diagenesis in lake sediments. Geochimica et Cosmochimica Acta.

  • Dumaresq, C.G. (1993). The occurrence of arsenic and heavy metal contamination from natural and anthropogenic sources in the Cobalt area of Ontario. M.Sc. Thesis, Department of Earth Sciences, Carleton University, Ottawa, Canada.

  • EBA Engineering Consultants Ltd. (2001). Assessment of Back Bay tailings deposit, Giant Mine Yellowknife, NWT. Project No. 0701-99-14263.008.

  • Fawcett, S. E., Jamieson, H. E., Nordstrom, D. K., & McCleskey, R. B. (2015). Arsenic and antimony geochemistry of mine wastes, associated waters and sediments at the Giant Mine, Yellowknife, Northwest Territories. Canada. Applied Geochemistry., 62, 3–17.

    Article  CAS  Google Scholar 

  • Galloway, J. M., Swindles, G. T., Jamieson, H. E., Palmer, M., Parsons, M. B., Sanei, H., Macumber, A. L., Patterson, R. T., & Falck, H. (2017). Organic matter control on the distribution of arsenic in lake sediments impacted by ~65 years of gold ore processing in subarctic Canada. Science of the Total Environment. In press.

  • Golder Associates Ltd., Consultants. (2002). Report on environmental assessment, Yellowknife Bay Tailings, Giant Mine, Yellowknife, NT. Report to Miramar Giant Mine Limited, Yellowknife, NWT.

  • Grunsky, E. C., Mueller, U. A., & Corrigana, D. (2014). A study of the lake sediment geochemistry of the Melville Peninsula using multivariate methods: applications for predictive geological mapping. Journal of Geochemical Exploration.

  • Harris, J. R., & Grunsky, E. C. (2015). Predictive lithological mapping of Canada's North using random forest classification applied to geophysical and geochemical data. Computers and Geoscience.

  • Hawley, J. (1980). The chemical characteristics of mineral tailings in the Province of Ontario, 1979. Ontario Ministry of the Environment.

  • Health Canada. (2014). Guidelines for Canadian drinking water quality—summary table. Water and Air Quality Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario.

  • Heiri, O., Lotter, A. F., & Lemcke, G. (2001). Loss on ignition as a method for estimating organic and carbon content in sediments: reproducibility and comparability of results. Journal of Paleolimnology, 25, 101–110.

    Article  Google Scholar 

  • Houben, A. J., D’Onofrio, R., Kokelj, S. V., & Blais, J. M. (2016). Factors affecting elevated arsenic and methyl mercury concentrations in small shield lakes surrounding gold mines near the Yellowknife, NT, (Canada) Region. PLoS One.

  • Jambor, J.L. (1971). General geology. In: Berry, L.G. (Ed.), The silver–arsenide deposits of the Cobalt–Gowganda Region, Ontario. Canadian Mineralogist, vol. 11, pp. 12–33.

  • Kihlman, S., & Kauppila, T. (2010). Tracking the aquatic impacts of a historical metal mine using lacustrine protists and diatom algae. Mine, Water, and the Environment.

  • Knight, C.W. (1922). Geology of the mine workings of Cobalt and South Lorrain silver areas. Ontario Department of Mines. 31st Annual report, Volume 31, Part 2.

  • Martin, A. J., & Pedersen, T. F. (2002). Seasonal and inter-annual mobility of As in a lake impacted by metal mining. Environmental Science & Technology., 36(7), 1516–1523.

    Article  CAS  Google Scholar 

  • Matchullat, J., Ottenstein, R., & Reimann, C. (2009). Geochemical background—can we calculate it? Environmental Geology.

  • McIlwaine, W.H. (1970). Geology of the South Lorrain Township, District Timiskaming, Ontario Geological Survey, Geological Report R83. 117p.

  • Miller, W.G. (1908). The cobalt-nickel arsenides and silver deposits of Temiskaming, 3rd Ed.; Ontario Bureau of Mines Report, Vol. XVI, pt. 11, pp. 1–212.

  • Nikolaidisa, N. P., Dobbsb, G. M., Chenc, J., & Lackovicc, J. A. (2004). Arsenic mobility in contaminated lake sediments. Journal of Environmental Pollution.

  • Oksanen, J., Blanchet, F.G., Friendly, M., Kindt, R., Legendre, P., McGlinn, D., Minchin, P.R., O’Hara, R.B., Simpson, G.L., Solymos, P., Stevens, M.H.H., Wagner, H. (2016) vegan: community ecology package. R package version 2.4–4.

  • Panahi, A., Cheng, Q., & Bonham-Carter, G. F. (2004). Modelling lake sediment geochemical distribution using principal component, indicator kriging and multifractal power spectrum analysis, a case study from Gowganda, Ontario. Geochemistry: Exploration, Environment, Analysis.

  • Percival, J. B., Kwong, Y. T. J., Dumaresq, C. G., & Michel, F. A. (2004). Transport and attenuation of arsenic, cobalt and nickel in an alkaline environment (Cobalt, Ontario). Geological Survey of Canada, Open File, 1680, 30p.

  • Petruk, W. (1971). Geochemistry of the ores. In Berry, L.G. (ed.): The silver-arsenide deposits of the Cobalt-Gowganda Region, Ontario. The Canadian Mineralogist, Vol. 11, Pt. 1, pp.140–149.

  • R Core Team. (2016). R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. Accessed Feb 19 2018.

  • Reid, F.D., J.J. Denny, and R.H. Hutchison. 1922. Milling and metallurgical practice in treatment of silver ores at Cobalt. Ontario Department of Mines. 31st annual report, Volume 31, Part 2.

  • Reimann, C., Filzmoser, P., & Garrett, R. G. (2005). Background and threshold: critical comparison of methods of determination. Science of the Total Environment.

  • Sprague, D. (2017) Lake sediment geochemistry in northeastern Ontario; the geologic controls on natural background variation and investigating lakes contaminated with arsenic-rich mine tailings in Cobalt, ON. M.Sc. Thesis, Department of Earth Sciences, Carleton University, Ottawa, Canada.

  • Sprague, D. D., Michel, F. A., & Vermaire, J. C. (2016). The effects of migration on ca. 100-year-old arsenic-rich mine tailings in Cobalt, Ontario, Canada. Environmental Earth Sciences.

  • Takats, P.A., Dyer, R.D. (2004). Temagami area lake sediment geochemical survey, northeastern Ontario; Ontario Geological Survey, Open File Report 6144, 113p.

  • Templ, M., Hron, K., Filzmoser, P. (2011). robCompositions: an R-package for robust statistical analysis of compositional data. In: V. Pawlowsky-Glahn and A. Buccianti, editors, Compositional data analysis. Theory and applications, pp. 341–355, John Wiley & Sons, Chichester (UK).

  • Thienpont, J. R., Korosi, J. B., Hargan, K. E., Williams, T., Eickmeyer, D. C., Kimpe, L. E., Palmer, M. J., Smol, J. P., & Blais, J. M. (2016). Multi-trophic level response to extreme metal contamination from gold mining a subarctic lake. Proceedings of the Royal Society: Biological Sciences.

  • Thomson, R. (1964). Cobalt Silver Area, Northern, Southeastern and Southwestern Map Sheets, Ontario Geological Survey, Maps M2050, M2051, M2052, scale 1:12,000.

  • Wang, S., & Mulligan, C. N. (2006). Occurrence of arsenic contamination in Canada: sources, behavior and distribution. Science of the Total Environment., 366, 701–722.

    Article  CAS  Google Scholar 

  • Wei, C., & Wen, H. (2012). Geochemical baselines of heavy metals in the sediments of two large freshwater lakes in China: implications for contamination character and history. Environmental Geochemistry and Health.

  • Zaharescu, D. G., Hooda, P. S., Soler, A. P., Fernandez, J., & Burgelea, C. I. (2009). Trace metals and their source in the catchment of the high altitude Lake Respomuso. Central Pyrenees. Science of the Total Environment.

Download references


The authors would like to thank Dr. Fred Michel for helpful discussions on the history of mining and arsenic contamination in the Cobalt region. This research was funded by an NSERC Discovery Grant to JCV.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Dale D. Sprague.

Electronic supplementary material


(DOCX 67 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Sprague, D.D., Vermaire, J.C. Legacy Arsenic Pollution of Lakes Near Cobalt, Ontario, Canada: Arsenic in Lake Water and Sediment Remains Elevated Nearly a Century After Mining Activity Has Ceased. Water Air Soil Pollut 229, 87 (2018).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI:


  • Environmental arsenic
  • Lake sediment
  • Geochemical background
  • Legacy contamination
  • Aquatic restoration
  • Cobalt, Ontario