British Columbia Mine Reclamation Symposium

Benthic invertebrate community recovery in a remediated stream Batchelar, Katharina; Stecko, Pierre; Hughes, Colleen

Abstract

A foundational failure of the perimeter embankment of the Mount Polley Mine Tailings Storage Facility (TSF) on August 4th 2014 resulted in a breach that released approximately 25 million cubic meters of debris (water and solids that consisted of tailings, construction materials, and scoured sediment and soil). The debris flowed along the entire length of Hazeltine Creek, scouring native materials and depositing TSF material in the creek channel. A first phase of channel remediation in Hazeltine Creek was completed in 2015, and a second phase which incorporated natural geomorphological and fish habitat values was completed in 2016 and 2017. Benthic invertebrate community monitoring was completed most recently in these remediated areas in 2017 and 2018. This monitoring documented rapid recolonization on the basis of organism densities that were similar to pre-breach in some areas, including colonization by sensitive EPT taxa. A number of differences relative to pre-breach remained, indicating that the community was still recovering from physical disturbances associated with the remediation work (including the influences of ongoing work on downstream areas). These included lower organism density in some areas, lower taxon richness, and a community that was dominated by early successional or tolerant taxon groups.

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Attribution-NonCommercial-NoDerivatives 4.0 International