Wernick, BG, Nikl, LH & Stevens, CE 2022, 'Aquatic habitat remediation following a mine tailings storage facility embankment breach', in AB Fourie, M Tibbett & G Boggs (eds), Mine Closure 2022: 15th International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 927-940, https://doi.org/10.36487/ACG_repo/2215_67
The Mount Polley Mine in British Columbia, Canada, is an open pit and underground copper and gold mine. In August 2014, the failure of a glacial lacustrine layer beneath the perimeter embankment of the tailings storage facility (TSF) resulted in the release of a slurry of water, tailings, and dam construction material. The material released from the breach and the resulting debris flow resulted in physical impacts to adjacent creek and lake environments. Following the TSF breach, an adaptive remediation framework was developed to guide and communicate the process of investigation, pollution abatement measures, and remediation of areas affected by the breach. Following the initial response that was focused on the immediate need of establishing safe work conditions and controlling further release from the TSF, a tabular format remediation plan was used to communicate short-term actions, such as re-establishing an erosion-resisting creek channel, presumed longer-term actions based on information yet to come in, and steps being taken to address those information gaps to the public, government and Indigenous groups on whose traditional territory the mine is located. A conceptual, and then final, remediation plan was developed while remedial actions based on decisions already being made were implemented. Remedial construction in the creek habitats concluded in the fall of 2021, in time for a run of sockeye salmon to spawn in the newly constructed channel.
The preliminary assessment of effects on aquatic and terrestrial resources found that copper, the contaminant of primary concern associated with the tailings, had low bioavailability. This was a key finding that helped focus remediation efforts on impacts associated with physical scouring of natural sediments, soils and vegetation, and deposit of tailings in riparian areas and water bodies. In creek habitats, the overall remediation objective was to restore the life history functions of fish by first constructing an erosion-resistant, field-engineered stream base in the otherwise erodible glacial lacustrine native soils underlying the area, onto which habitat features (cover, riffle-to-pool ratios, substrate, etc.) were added to enhance aquatic ecosystem functions for spawning and rearing fish. Adjacent riparian areas were stabilised through contouring and planting a mix of local species to establish a successional vegetation community. Evaluation of post-construction habitat suggests that remediation will restore the productive capacity of the aquatic ecosystem for salmonids, and that recovery will be relatively quick, with projected population sizes stabilising above historical levels within 20 years of the TSF breach event. In the lake habitats, monitored natural recovery was recommended based on a net environmental benefit assessment that found that physical removal of deposited tailings would be detrimental to natural recovery already taking place.
Keywords: habitat reconstruction, remediation framework
Bradford, MJ, Smokorowski, KE, Clarke, KD, Keatley, BE, Wong, MC 2016, Equivalency Metrics for the Determination of Offset Requirements for the Fisheries Protection Program, Department of Fisheries and Oceans Canadian Science Advisory Secretariate Research Document - 2016/046, Fisheries and Oceans Canada.
Bronsro, A, Ogilvie, J, Nikl, L, & Adams, M 2016, ‘River rehabilitation following a tailings dam embankment breach and debris flow’, Proceedings of the 20th International Conference on Tailings and Mine Waste, The University of British Columbia, Vancouver,
Clarke, KD & Bradford, MJ 2014, A Review of Equivalency in Offsetting Policies, Department of Fisheries and Oceans Canadian Science Advisory Secretariate Research Document 2014/109, Fisheries and Oceans Canada.
de Kerckhove, DT 2015, Promising Indicators of Fisheries Productivity for the Fisheries Protection Program Assessment Framework, Canadian Science Advisory Secretariate Research Document - 2014/108, Fisheries and Oceans Canada.
Department of Fisheries and Oceans 2012, Pathways of Effects: National Guidelines. Illustrating the Links Between Human Activity and its Potential Impact on Aquatic Ecosystems, Ottawa.
Department of Fisheries and Oceans 2013, Fisheries Productivity Investment Policy: a Proponent’s Guide to Offsetting, Ottawa.
Department of Fisheries and Oceans 2019a, Fish and Fish Habitat Protection Policy Statement, Ottawa.
Department of Fisheries and Oceans 2019b, Policy for Applying Measures to Offset Adverse Effects on Fish and Fish Habitat Under the Fisheries Act, Ottawa.
Efroymson, RA, Nicolette, JP & Suter II, GW 2003, A Framework for Net Environmental Benefit Analysis for Remediation or Restoration of Petroleum-Contaminated Sites, Oak Ridge National Laboratory Technical Memo ORNL/TM-2003/17.
Golder Associates Ltd. 2016, Mount Polley Mine Tailings Storage Facility, Perimeter Embankment Breach Update Report; Post-Event Environmental Impact Assessment, viewed 13 September 2022,
Golder Associates Ltd. 2017a, Mount Polley Rehabilitation and Remediation Strategy: Human Health Risk Assessment, viewed 13 September 2022,
Golder Associates Ltd. 2017b, Mount Polley Rehabilitation and Remediation Strategy: Ecological Risk Assessment, viewed 13 September 2022,
Golder Associates Ltd. 2019, Remediation plan: Mount Polley Mine Perimeter Embankment Breach, viewed 13 September 2022,
Golder Associates Ltd. 2021, Projected Population Recovery of Hazeltine Creek Rainbow Trout, Reach 1 Through Reach 3.
Government of Canada 1985, Fisheries Act, Canada.
Hickman, T & Raleigh, RF 1982, Habitat Suitability Index Models: Cutthroat Trout, Fish and Wildlife Services, Biological Services Program FWS/OBS-82/10.5, US Fish and Wildlife Service.
Independent Expert Engineering Investigation and Review Panel 2015, Independent Expert Engineering Investigation and Review Panel: Report on Mount Polley Tailings Storage Facility Breach,
Johnston, NT & Slaney PA 1996, Fish habitat assessment procedures, Watershed Restoration Technical Circular, no. 8, Ministry of Environment, Lands and Parks, and Ministry of Forests.
Kennedy, CB, Day, SJ & Anglin, CD 2016, ‘Geochemistry of tailings from the Mount Polley Mine, British Columbia’, Proceedings of the 20th International Conference on Tailings and Mine Waste, The University of British Columbia, Vancouver, pp. 857–868.
Kohler, KE & Dodge, RE 2006, ‘Visual HEA: habitat equivalency analysis software to calculate compensatory restoration following natural resource injury’, Proceedings of the 10th International Coral Reef Symposium, Japanese Coral Reef Society, Kochi,
Larkin, DJ, Madon, SJ, West, JM & Zedler, JB 2008, ‘Topographic heterogeneity influences fish use of an experimentally restored tidal marsh’, Ecological Applications, vol. 18, pp. 483–496.
Larson, MA, Thompson III, FR, Millspaugh, JJ, Dijak, WD & Shifley, SR 2004, ‘Linking population viability, habitat suitability, and landscape simulation models for conservation planning’, Ecological Modelling, vol. 180, pp. 103–118.
Laval, BE, Morrison, J, Potts, DJ, Carmack, EC, Vagle, S, James, C, McLaughlin, FA & Foreman, M 2008, ‘Wind-driven summertime upwelling in a fjord-type lake and its impact on downstream river conditions: Quesnel Lake and River, British Columbia, Canada’, Journal of Great Lakes Research, vol. 34, pp. 189–203.
Loughlin, KG & Clarke, KD 2014, A Review of Methods used to Offset Residual Impacts of Development Project on Fisheries Productivity, Department of Fisheries and Oceans Canadian Science Advisory Secretariat Research Document – 2013/097, Fisheries and Oceans Canada.
Mindus, A 2018, ‘Sockeye salmon return in droves to Quesnel Lake watershed’, Williams Lake Tribune, viewed 6 June 2022,
Minns, CK 1997, ‘Quantifying “no net loss” of productivity of fish habitats’, Canadian Journal of Fisheries and Aquatic Sciences, vol. 54, pp. 2463–2473.
Minns, CK, Randall, RG, Smokorowski, KE, Clarke, KD, Vélez-Espino, A, Gregory, RS, Courtenay, S & LeBlanc, P 2011, ‘Direct and indirect estimates of the productive capacity of fish habitat under Canada’s policy for the management of fish habitat: where have we been, where are we now, and where are we going?’, Canadian Journal of Fisheries and Aquatic Sciences, vol. 68,
Mount Polley Mining Corporation 2015, Post-Event Environmental Impact Assessment Report – Key Findings Report, viewed 13 September 2022,
National Oceanic and Atmospheric Administration 1995, Habitat Equivalency Analysis: An Overview, NOAA Damage Assessment and Restoration Program, Policy and Technical Paper Series, No. 95-1 (revised 2006), Washington.
Newbury, RW & Gabourey, MN 1993, Stream Analysis and Fish Habitat Design: A Field Manual, Newbury Hydraulics Ltd, Gibsons,
Nikl, L, Wernick, B, Van Geest, J, Hughes, C, McMahen, K & Anglin, CD 2016, ‘Mount Polley mine embankment breach: overview of aquatic impacts and rehabilitation’, Proceedings of the 20th International Conference on Tailings and Mine Waste,
The University of British Columbia, Vancouver,pp. 845–856.
Ogilvie, J, Topps, H & Nikl, L 2018, ‘An innovative approach to monitoring the physical stability of constructed fish habitat using drones’, British Columbia Mine Reclamation Symposium, The University of British Columbia, Vancouver.
Polster, DF 2009, ‘Natural processes: the application of natural systems for the reclamation of drastically disturbed sites’, British Columbia Mine Reclamation Symposium.
Schamberger, M, Farmer, AH & Terrell, TJ 1982, Habitat Suitability Index (HSI) Models: Introduction, US Fish and Wildlife Service Special Report FWS-OBS-82-10, US Fish and Wildlife Service, Washington.
Slaney, PA & Zaldokas, D 1997, ‘Fish habitat rehabilitation procedures’, Forests Watershed Technical Circular, no. 9, Ministry of Environment, Lands and Parks and BC Ministry of Forests.
United States Fish and Wildlife Service 1981, Standards for the Development of Habitat Suitability Index Models, ESM 103, US Fish and Wildlife Service, Washington.