Predicting retention of diluted bitumen in marine shoreline sediments, Southeastern Vancouver Island, British Columbia, Canada

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dc.contributor.author Britton, Lee Allen Sean
dc.date.accessioned 2017-12-22T20:57:01Z
dc.date.copyright 2017 en_US
dc.date.issued 2017-12-22
dc.identifier.uri https://dspace.library.uvic.ca//handle/1828/8917
dc.description.abstract Canada has become increasingly economically dependent on the exportation of bitumen to trans-oceanic international markets. As the export of Alberta bitumen from ports located in British Columbia increases, oil spill response and readiness measures become increasingly important. Although the frequency of ship-source oil spills has dramatically declined over the past several decades, they remain environmentally devastating when they occur. In the event of a marine spill, great lengths of shoreline are at risk of being contaminated. Once ashore, oil can persist for decades if shoreline hydraulic conditions are correct and remediation does not occur. Most commonly transported oils (e.g., fuel oils, Bunker C, crude oil, etc.) have been thoroughly studied, and their fate and behaviour in the event of a marine spill is well understood. In contrast, because diluted bitumen has been historically traded in relatively low quantities and has almost no spill history, there is a sizable knowledge gap regarding its effects and behaviour in both the marine environment and on coastal shorelines. The intent of this thesis was to develop a classification scheme to identify marine shorelines of high and low diluted bitumen (dilbit) retention for southeastern Vancouver Island, British Columbia. This study builds upon the outcome of former laboratory bench top dilbit and sediment research known as Bitumen Experiments (Bit_Ex). Bit_Ex investigated dilbit penetration and retention in six engineered sediment classifications ranging from coarse sand to very large pebble in accordance with the Wentworth Classification scheme. This research used Bit_Ex findings to predict dilbit retention in poorly sorted in-situ beach sediments found on shorelines representative of the southern coast of Vancouver Island, British Columbia, Canada. Field and laboratory measurements were conducted to document the occurrence of in-situ shoreline sediments and hydraulic conditions and were used to predict dilbit retention by comparing such characteristics between Bit_Ex and unconsolidated in-situ beach sediments. Saturated hydraulic conductivity (Ks) was measured using a double-ring constant-head infiltrometer. Measured Ks values were then compared to predicted Ks values generated by five semi-empirical Ks equations. A modified version of the Hazen Approximation was selected as the most appropriate. Using measured and calculated metrics, sediments were grouped as having either low or high dilbit retention. When sediments were analysed as homogenous samples, the experimental results suggested two of ten shorelines were composed of a combination of low and high retention sections, while the remaining eight sites were of low retention. Upon the isolation of coarse surface strata, results indicated two shorelines were entirely veneered with high retention sediments, and four shorelines were a combination of high and low retention. The residual four shorelines were found to be entirely composed of low retention sediments. The results illuminate the importance of shoreline stratification when predicting shoreline oil retention. This characteristic is a factor that current shoreline oil retention mapping techniques do not adequately consider. Additionally, the findings suggest that while sediments indicative of retaining weathered dilbit are relatively uncommon within Juan de Fuca and Harro Straits, high retention unweathered dilbit sediments are more common. en_US
dc.language English eng
dc.language.iso en en_US
dc.rights Available to the World Wide Web en_US
dc.subject marine oil spill en_US
dc.subject diluted bitumen en_US
dc.subject dilbit en_US
dc.subject shoreline oil retention en_US
dc.subject sediment oil hydraulics en_US
dc.subject marine shoreline contamination en_US
dc.subject oil spill en_US
dc.subject shoreline oil retention model en_US
dc.title Predicting retention of diluted bitumen in marine shoreline sediments, Southeastern Vancouver Island, British Columbia, Canada en_US
dc.type Thesis en_US
dc.contributor.supervisor Harper, J. R.
dc.contributor.supervisor Smith, Daniel J.
dc.degree.department Department of Geography en_US
dc.degree.level Master of Science M.Sc. en_US
dc.identifier.bibliographicCitation Harper, J., Sergy, G., Britton, L., and Kory, M. 2016. Diluted Bitumen Sediment Interaction Experiments; Bit_Ex. Ottawa, ONT. 1-88. en_US
dc.description.scholarlevel Graduate en_US
dc.description.embargo 2018-06-26

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