Open Collections

Mount Polley mine tailings : uptake and distribution of metals in lodgepole pine and bluebunch wheatgrass under controlled environments

University of British Columbia

On August 4th, 2014, a partial breach of the Mount Polley Mine tailings storage facility (TSF) released over 4.6 million m³ of supernatant water, and 12.8 million m³ of slurry tailings (solids and interstitial water) into Polley lake and downstream of Hazeltine Creek into Quesnel Lake. The spill led to an enrichment of copper and selenium into the affected ecosystem. Concentrations of copper and vanadium in sandy and silty tailings exceeded provincial soil quality standards for the protection of parkland use. A study of potential toxicity of deposited tailings to plants was conducted to determine if the tailings material would support growth of plants representative of the biogeoclimatic zone; more specifically, the growth and uptake of metals in root and shoot tissue of lodgepole pine (Pinus contorta), and bluebunch wheatgrass (Pseudoroegneria spicata). The greenhouse study identified physical growth-limiting factors of hexagonal closed packing and surface crusting in silty tailings. The Environment Canada (2007)-compliant 42-day growth chamber study found seedling emergence and survival not affected in plants growing in tailings or in copper-spiked greenhouse soils. Copper uptake was significant in roots and shoots of both species grown in tailings. Neither species survived in 115 mg/kg of copper-spiked sandy and silty substrates as a result of osmotic burning from the high salt index of copper sulfate. A separate 100-day growth chamber study found proportionally greater copper uptake in roots of lodgepole pine and in shoots of bluebunch wheatgrass compared to the 42-day study. Lodgepole pine and bluebunch wheatgrass each showed various qualitative signs of phytotoxicity. The presence of metals and their respective associations to one another in tailings may have profound implications on species-specific phytotoxicity otherwise not found in the studies conducted. Results of this study contributed to the shaping of future terrestrial restoration at Hazeltine Creek.

Text

2018-04-18

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/65448

Soil Science

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/