Annual pulses of copper-enriched sediment in a North American river downstream of a large lake following the catastrophic failure of a mine tailings storage facility

P N Owens; E L Petticrew; S J Albers; T D French; B Granger; B Laval; J Lindgren; R Sussbauer; S Vagle

doi:10.1016/j.scitotenv.2022.158927

Annual pulses of copper-enriched sediment in a North American river downstream of a large lake following the catastrophic failure of a mine tailings storage facility

Sci Total Environ. 2023 Jan 15;856(Pt 1):158927. doi: 10.1016/j.scitotenv.2022.158927. Epub 2022 Sep 22.

Authors

P N Owens¹, E L Petticrew², S J Albers³, T D French², B Granger⁴, B Laval⁵, J Lindgren⁶, R Sussbauer², S Vagle⁷

Affiliations

¹ Department of Geography, Earth and Environmental Sciences, University of Northern British Columbia, Prince George, British Columbia V2N 4Z9, Canada; Quesnel River Research Centre, University of Northern British Columbia, Likely, British Columbia V0L 1N0, Canada. Electronic address: Philip.owens@unbc.ca.
² Department of Geography, Earth and Environmental Sciences, University of Northern British Columbia, Prince George, British Columbia V2N 4Z9, Canada; Quesnel River Research Centre, University of Northern British Columbia, Likely, British Columbia V0L 1N0, Canada.
³ Department of Geography, Earth and Environmental Sciences, University of Northern British Columbia, Prince George, British Columbia V2N 4Z9, Canada.
⁴ Quesnel River Research Centre, University of Northern British Columbia, Likely, British Columbia V0L 1N0, Canada; Department of Civil Engineering, University of British Columbia, Vancouver, British Columbia, Canada.
⁵ Department of Civil Engineering, University of British Columbia, Vancouver, British Columbia, Canada.
⁶ Quesnel River Research Centre, University of Northern British Columbia, Likely, British Columbia V0L 1N0, Canada.
⁷ Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, Canada.

PMID: 36152844
DOI: 10.1016/j.scitotenv.2022.158927

Abstract

Failures of mine tailings storage facilities (TSF) can have profound and long-lasting effects on the downstream receiving environment. Virtually all spills to date have been into river systems without large lakes that may buffer downstream impacts. In August 2014, the failure of the Mount Polley copper (Cu)-gold mine TSF in British Columbia, Canada, released ~25 × 10⁶ m³ of water and solids; globally, this is the second largest TSF spill in history. Over 18 × 10⁶ m³ was delivered to Quesnel Lake, which is ~9 km from the TSF and is the third deepest lake in North America, and a crucial habitat for Pacific salmon and trout populations. We determined the sediment-associated Cu concentrations and fluxes in Quesnel River, downstream of the lake, from August 2014 to February 2021 based on the analysis of >400 samples of sediment, mainly collected using a continuous-flow centrifuge. During each winter since the spill, Cu concentrations in the fluvial sediment in the upper reaches of the river (~35 km from the TSF) were elevated relative to regional background concentrations and samples collected before the spill. Maximum Cu concentrations were ~410 mg kg^-1 which exceeds Canadian sediment quality guidelines for the protection of aquatic organisms (197 mg kg^-1). Monitoring of Quesnel Lake since the spill shows that these annual pulses in the winter are due to resuspension of unconsolidated tailings and sediments at the bottom of Quesnel Lake, during autumnal lake turnover, which become mixed throughout the water column and subsequently flow into Quesnel River. Results show that while large lakes may buffer downstream aquatic systems from contaminated sediment, they may prolong the environmental impact. These findings are crucial in understanding how lake processes may modify the effects of TSF spills on downstream aquatic systems.

Keywords: Contaminant fluxes; Downstream impacts; Mine tailings; Mount Polley mine; Quesnel River watershed; Salmon habitat.

MeSH terms

British Columbia
Copper / analysis
Environmental Monitoring
Geologic Sediments / analysis
Lakes*
Water / analysis
Water Pollutants, Chemical* / analysis

Substances

Copper
Water
Water Pollutants, Chemical