Post on 27-Jul-2020
Remediation and Risk Management of Extractable Petroleum Hydrocarbon Contamination in Freshwater Sediments
BC PerspectiveRemTech – October 20th, 2011
2 1-Nov-11
Outline
Site OverviewCollapsed AreaInvestigationRemediationRisk Assessment Risk ManagementConclusions
Site Overview
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Site Overview
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Site Overview
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1938
1963
2010
Site Overview
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Collapsed Area
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Investigation
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Collapsed wharf
View from under the wharfPartially buried metal debris piles
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So….
Because of the debris, APEC 4 was carried forward as an AEC.
“Let’s remove the metal mounds so there is better habitat in the Fraser River…”
Remediation
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Intact metal debris pilePile removed Oil released when piles were removed
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How do we know when we can stop sediment remediation?
Risk Assessment
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Risk Assessment
Benchmarks
Habitat
Physical-chemical properties
Toxicity Testing
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Risk Assessment
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10-day14-day
Risk Assessment
H.azteca– % survival: no significant effects
Chironomids– % survival and growth: no significant effects
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Risk Assessment
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½ MDL
Control 1
20% Effects Level
50% Effects Level
Control 2
Toxicity Test Results – Growth of H. azteca
20% Effects Level
Risk Management
Lines of Evidence– Habitat– Physico-chemical properties– Toxicity testing
Considerations– Erosional and depositional– River flow– Artesian groundwater
Mitigation– Cap design
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Conclusions
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Before
February, 2010
After
August, 2011
Acknowledgements
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