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| Titel |
The long-term environmental impacts of the Mount Polley mine tailings spill, British Columbia, Canada |
| VerfasserIn |
Patrick Byrne, Karen Hudson-Edwards, Mark Macklin, Paul Brewer, Graham Bird, Richard Williams |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250106564
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| Publikation (Nr.) |
 EGU/EGU2015-6241.pdf |
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| Zusammenfassung |
| On the 4th August 2014 a tailings impoundment failure at the Mount Polley gold and copper
mine in British Columbia, Canada, released approximately 25 million m3 of solid and liquid
waste into Hazeltine Creek, Quesnel Lake and Polley Lake. The sheer volume of
the tailings released caused Haseltine Creek channel to expand from 2m to over
25m in width and Polley Lake water level to rise by 1.7m. The spill also removed
trees in a 900 km2 corridor either side of Hazeltine Creek. Local residents and
government officials have expressed serious concerns regarding the potential long-term
effects on regional biodiversity, water security and to the livelihoods of First Nation
communities.
Among impoundment failures, the Mount Polley disaster is unique in that the solid
tailings contain an unusual mixture of metal contaminants (arsenic, copper, gold, manganese,
nickel, lead, vanadium). As particulate matter is the principal carrier of metal contaminants,
the spilled tailings may reside in the regional soils and sediments for 1000s of years
serving as a secondary source of pollution. The environmental risk posed by the
spilled tailings is compounded by the location of the spill in a mountainous forested
catchment, affected by severe winters with prominent spring snow melts that have the
potential to remobilise very large quantities of spilled tailings. No data currently
exist on the short- to long-term behaviour of these tailings in soils and sediments
and the effects of the clean-up operations on their behaviour in this type of river
environment.
In this study, we adopt a multidisciplinary approach to determine the environmental and
geomorphological impacts of the tailings spill. We have two specific objectives. (1) The
physicochemical speciation and geochemical stability of spilled tailings will be characterised
in surface and hyporheic sediments using bulk chemistry, mineralogical (XRD and SEM) and
speciation methods (sequential extractions, electron microprobe analysis, XAS). (2)
Pre- and post-remediation geomorphological assessments will use unmanned aerial
vehicle (UAV) photographic surveys and ground-based topographic surveys to (i)
establish the efficacy of remediation efforts in stabilising Hazeltine Creek channel and
(ii) quantify the physical remobilisation of tailings during the spring snowmelt. |
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