Centrifuged fine tailings (CFT) technology was developed to reduce volumes of fluid fine tailings (FFT) stored in tailings ponds at oil sands mines. Increasing FFT inventories in tailings ponds results from slow settlement of clay minerals suspended in oil sands process-affected water (OSPW). High sodium (Na) concentrations in OSPW increase the electrical double layer (EDL) thickness at clay-mineral surfaces, which hinders aggregation and, therefore, settlement. Production of CFT involves dredging FFT from tailings ponds, amending with polyacrylamide and gypsum, and decanter centrifuging. This process promotes aggregation and flocculation, and decreases gravimetric water content from approximately 70 to 55 % (w/w). The resulting CFT is deposited in thin lifts (< 2 m) into sub-aerial containment areas to facilitate further dewatering via freeze-thaw cycling. This research was focused on characterizing the biogeochemical conditions and processes within the CFT deposits. These deposits remain tension-saturated and, similar to tailings ponds, anaerobic redox processes including iron (Fe) reduction, sulfate (SO4) reduction, and methanogenesis likely dominate. The geochemistry, mineralogy, and microbiology of core samples from two field-scale test deposits and two full-scale production deposits were examined. Results were compared with previously published data from FFT deposits to assess impacts of chemical amendments on biogeochemical processes within CFT deposits. Pore-water chemistry within the CFT deposits is affected by evaporative concentration of dissolved ions, which leads to high concentrations of salts (Na, 3000 mg L-1; Cl, 1500 mg L-1; SO4, 5000 mg L-1) and naphthenic acids (NAs 150 mg L-1) near the surface (< 0.3 m) of these deposits. Increases in concentrations of conservative ions (i.e., Cl) indicated that 30 to 40 % of pore water was lost to evaporation at a depth of 0.1 m below surface. Results also suggest that microbially-mediated Fe reduction, SO4 reduction, and methanogenesis are dominant redox processes within the CFT deposits. Microbes related to genera known to use these terminal electron acceptors were identified by high-throughput DNA sequencing data. Increases in dissolved Fe and H2S with depth were also indicative of Fe and SO4 reduction, respectively. These results provide the first insight into biogeochemical conditions and processes within oil sands CFT deposits.

Bitumen extraction in the Athabasca oil sands in Alberta releases metals to the region. In this study, I performed an uptake-elimination experiment with wood frog tadpoles (Lithobates sylvaticus) to determine the bioaccumulation potential of metals from exposure to MacKay River sediment, an area affected by oil sands contamination, and to uncontaminated reference sediment. Wood frog tadpoles, Gosner stages 28-32, were exposed to two sediments: (1) MacKay River sediment that is enriched in petrogenic hydrocarbons from natural and anthropogenic sources; and (2) an uncontaminated reference sediment. Tadpole exposures to sediments lasted 4 days, followed by a depuration phase for an additional 4 days where tadpoles were allowed to eliminate excess metals from their bodies. The metal concentrations at various time points during the uptake and elimination phases were determined in order to define toxicokinetic parameters, such as uptake and elimination first order rate constants, accumulation by ingestion, and assimilation efficiencies for specific metals. It was determined that tadpoles exposed to the MacKay sediment had higher concentrations of Al, Co, Cu, Cr, Mg, Ni, Pb, V, and Zn throughout the uptake phase of the study compared to tadpoles exposed to reference sediment. We also observed little to no decrease in concentrations of Al, Co, Cu, Cr, Mg, Ni, Pb, V, and Zn throughout the elimination phase of the study. In addition, biota-sediment accumulation factors (BSAF) revealed that Cu, Zn, Cr, and V had among the highest bioaccumulation potential in our trials. The experiment was subsequently repeated by preventing direct contact of the tadpoles to sediment with a screen, exposing tadpoles only to metals in water. By comparing tadpole exposures to metals from ‘aqueous’ and ‘aqueous +sediment’ in separate trials, and by tracking sediment ingestion rates, I am able to show that sediment ingestion constitutes the primary source of metal bioaccumulation by tadpoles. Not only were metal concentrations higher in tadpoles that were ingesting sediment, but they also had greater metal uptake rates compared to tadpoles that were only exposed to contaminated water. It was also determined that assimilation efficiencies were higher in tadpoles exposed to reference sediment compared to ones exposed to MacKay River sediment. Using toxicokinetic parameters defined by the uptake-elimination experiment, I developed a computational model using STELLATM system dynamics software to accurately estimate first order uptake and depuration rate constants for metals in exposed aquatic animals. The model estimated metal uptake and depuration kinetics with a mean relative error of 2.25 ± 0.93 % (±SE, n=9) for the uptake study and 2.53 ± 2.61 % (±SE, n=9) for the depuration study. With increased oil-sands production anticipated, we recommend continued monitoring of contaminants from oil-sands for the purpose of understanding the potential risks they may have on northern Alberta’s ecosystems.

Disturbance plays integral role in the vegetative communities and succession in northern Alberta. Fire is the most common natural disturbance, and oil industry disturbance is a rapidly increasing anthropogenic disturbance on the landscape. In situ extraction of deep oil sands is increasing across Alberta, and with it, minimum disturbance sites used for seismic exploration and natural gas extraction also increase. To determine how these sites recover after disturbance, a 21 year chronosequence was established to address the following questions: 1) How do the plant communities differ between natural bogs, recently burned bogs, and bogs disturbed by `minimum disturbance petroleum industry activities? 2) How do the environmental conditions compare between undisturbed bogs, burned bogs, and bogs disturbed by `minimum disturbance' petroleum industry activities? 3) What is the revegetation pathway of minimum disturbance sites disturbed over the 21 year period? 4) What is the revegetation pathway of the burned bogs over the 21 year disturbance span? and 5) How does the (anthropogenic) minimum disturbance revegetation pathway compare to that of the (natural) fire disturbed bogs? To answer these questions 55 stands were sampled. The plant species were identified and abundance recorded, water chemistry was analyzed, shade recorded, depth to water measured, and oldest trees aged. Bog plant communities and environmental conditions at sites surveyed are similar to one another. Burned bogs were also similar in chemistry, vegetation, and physical traits of the sites. Minimum disturbance sites were quite varied in plant species and environmental conditions studied. A minimum disturbance revegetation could not be determined due to the amount variation in plant species and abundances between minimum disturbance sites of the same age. Burned bogs showed more predictable species interactions: Polytrichum strictum establishes early and subsequently declines. Sphagnum fuscum becomes dominant between 15 and 20 years after disturbance, and Picea mariana returns to burned sites between 1 and 5 years after fire and continues to increase in density. Minimum disturbance sites do not recover in a predictable manner, and some sites become rich fens. It is not clear if these sites will return to the pre-disturbance mature bog community, but burned bogs have a community closely resembling a mature bog after 20 years of revegetation. Documentation of pre-disturbance conditions and operational protocols is recommended in order to further understand sources of cation rich waters that could yield rich fen habitats.

Anthropogenic development is altering watersheds and threatening freshwater ecosystems and the resources therein. Direct impacts of industry including conversion of land cover and increased water withdrawals from rivers, compounded with indirect influences such as climate change, collectively affect the health and sustainability of freshwater ecosystems. Many studies have indicated a suite of ecological impacts that large-scale anthropogenic land use and development impose on the structure and function of riverine systems. The overarching goal of this thesis was to examine the potential impacts associated with land use disturbance and Oil Sands (OS) mining operations on fish community composition patterns in three rivers located in the Athabasca Oil Sands Region (AOSR). Using historical data sets, this thesis attempted to evaluate disturbance-related patterns in fish community composition. Fish community-environmental relationships were investigated on a temporal scale, across which community composition could be constrained or altered by development. Structural and trait-based changes in fish community composition were analyzed to determine whether significant variation between levels of development (pre versus post) in the AOSR could be attributed to observed changes in fish community metrics. No significant difference in community composition patterns was observed between levels of development; however, there was a significant decline in fish species richness on a regional scale. The lack of significant results could be attributed to the limitations of the collected data, including temporal gaps, inconsistent sampling methods, and seasonal sampling inconsistencies. Furthermore, the scale of interpretation between individual tributaries and the regional datasets, demonstrates that studies of fish communities on a regional scale can elucidate different states of community change, implying that local controls can play a role in species presence/absence. An assessment of the features and patterns of the hydrograph that could explain variation in fish communities was constrained due to dataset and subsequent methodological limitations. Currently, there is an inability to link changes (historical) to hydrologic regimes, land use or development within these systems, and how they have impacted fish communities therein due to inconsistencies in the methods and sampling during most of the pre-development and for a portion of post- development time span (until 2009). Long-term, standardized community monitoring will be critical to gain a greater understanding of how land management practices affect fish communities and what kind of ecosystem management can mitigate impacts to streams, rivers and the biota therein. Further recommendations were made from synthesizing these findings in conjunction with relevant literature and are intended to provide an improved understanding of the long-term cumulative changes within these systems and to help guide and improve future monitoring plans in the AOSR. / Graduate

This study explores how the Canadian and Alberta governments downplay environmental harm in the Alberta Tar Sands, therein justifying its ongoing expansion and defining it as unnecessary to intervene through the law. In particular, this study draws on the concepts of hegemony, social harm and deep ecology to problematize how climate change has become the governments’ main environmental concern in the tar sands, despite the existence of other, equally troubling issues, and how carbon capture and storage (CCS) has become the states’ main climate change strategy, despite the largely untested nature of this technique. A critical discourse analysis of two government taskforce documents concerning CCS technology revealed that neoliberal and globalization discourses were used to narrowly conceptualize environmental harm, thereby privileging Canada’s trade relations and economic strength over the environment’s health. Relatedly, discourses of scientism were used to conceptualize climate change as a technical problem and CCS as the “preferred” solution.

In recent years, Canada's previously stable energy economy has undergone a series of remarkable changes. The early seventies, and particularly the dramatic OPEC price increases of 1973, have marked the advent of a new era in energy policy. Canadian governments seem unwilling to accept the fact that national net self-sufficiency in energy, particularly in oil, may well be a thing of the past. Thus, mammoth energy projects have been proposed or undertaken by industry and government alike, in a desperate attempt to reduce dependence on foreign sources of supply. This new sense of urgency has led to unprecedented co-operation between government and industry, while increasing the traditional tension amongst different levels of government. Typical both of the novel pattern of development and of the unusual government-industry alliance is the Syncrude project, the latest attempt at exploiting the Alberta oil sands. This paper investigates the potential role that the oil sands might play in Canada's energy future. Mora specifically, the economics of Syncrude itself are analysed, and conclusions of a general nature are based on this case study. In section 1, the reader is introduced to the topic through a description of the oil sands, a review of currently available recovery and refining methods, and a short history of oil sands development. Sections 2 and 3 constitute the main body of the paper, dealing first with the expected costs and benefits of the Syncrude project and, second, with the likely macroeconomic consequences. Finally, section -i explores the implications of more substantial oil sands development, compares the various techniques that might be employed in the future, and discusses the oil sands' role in the national energy policy. The conclusions of the paper have several dimensions. With regard to the cost-benefit analysis, Syncrude as a whole seems to be a rather marginal venture. Particularly interesting is the manner in which the returns are distributed among the various consortium members, as alberta and the private industry participants are subsidized by Ontario and the federal government. Although consideration of sunk costs at the time of Syncrude's "go" decision somewhat improves the basic economic picture, an analysis of risk and uncertainty demonstrates how sensitive returns are with respect to several unknown parameters. Some of the special arrangements of royalty and taxation that distinguish Syncrude from the petroleum industry in general are quantified, thus demonstrating the extent to which this project is being subsidized relative to others. Also, a crude appraisal of the scale economies in oil sands development is attempted. On the macroeconomic side, a dynamic simulation model of Syncrude is incorporated into RDX2, an aggregate econometric model of the Canadian economy. This enables an appraisal of the likely consequences that oil sands development may have for the national economy. The major conclusion is that such projects can hardly be justified on the basis of their aggregate effects, if the cost-benefit results are unfavourable. In the final section, an analysis of more intensive oil sands development (several Syncrude-size plants) shows that the present government-industry arrangements are unlikely to apply to future oil sands ventures. Thus, private industry will probably be dissuaded from engaging in further surface-mining schemes, pending some major cost-rsducing technological breakthrough and/or a substantial increase in the relative price of oil. Although similar financial and technical problems currently haunt 'in situ' development, it is believed that this recovery method will play a greater part in the oil sands' future. Finally, some critical remarks are included on the national energy policy and the governments' handling of Syncrude. An attempt is made to analyze why Ottawa, Alberta and Ontario decided to join the companies in an obviously marginal and risky undertaking. Sy results suggest that little, if any, analysis preceded either the federal or the Ontario government's decision to participate in the project. In this regard, I conclude that Syncrude could set a dangerous precedent for the future management of the country's resources. / Arts, Faculty of / Vancouver School of Economics / Graduate

Organoclays modelling the Athabasca oil sands were prepared in heptane and toluene showing indole loading occurring exclusively on the external surface of the clay, via a multilayer adsorption mechanism. Solvent adsorption was minimal. Vermicular microstructures, similar to natural kaolinite were formed. Isotherms were constructed and fitted to the BET equation, giving monolayer quantities (9.28mg) that matched well to the theoretical amount calculated from surface area measurements (8.87mg). Dispersing the organoclays in isopropanol and in toluene left a monolayer equivalent. Using cellulose as a competitive desorption agent in asphaltene based organoclay dispersions achieved complete disaggregation of the dispersed organoclay stacks.13 C CP - MAS NMR, showed up to a 25% increase in desorption for aliphatic and up to 40% increase in desorption for aromatic functionalities of the loaded organic matter. Investigation of other saccharides and modified celluloses as competitive agents is recommended for future work.

The extraction of bitumen from the cretaceous oil sands ore within the Athabasca Oil Sands Region (AOSR) in Northern Alberta has generated over 1.18 trillion liters of by product in the form of Fluid Fine Tailings (FFT) and Oil Sands Process Water (OSPW)3. A reclamation strategy being investigated is water capped tailings technology (WCTT), that involves the development of Pit Lakes (PLs) by sequestering FFT below a water cap composed of both OSPW and fresh water to steadily densify these tailings over time4. A challenge that may impede this reclamation strategy is that as FFT densifies porewater containing oxygen consuming constituents (OCC) derived from anaerobic microbial degradation of labile petroleum hydrocarbons, such as gases (e.g. H2S, CH4), dissolved organic carbon (DOC) and dissolved ions (e.g. NH4+, HS-, and Fe2+), have the potential to be mobilized into to the overlying water cap. This dissertation is focused on developing an optimized comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC/TOFMS) methodology for analyzing the spatial distribution for a subset of identifiable solvent extractable PHCs species from FFT within Base Mine Lake (BML) the first full-scale demonstration of PL technology. The chemical “fingerprint” constructed from the concentration of each identified PHC isomer at a given depth and cosine theta (cos-Ɵ) similarity metric suggested the contribution of a singular source of PHCs within BML. Although a similar source fingerprint persisted throughout the study site, the spatial distribution for the isomers identified suggested differences in PHC input contributions across the FFT sampling platforms with the largest variation in concentration being attributed to the labile low molecular weight n-alkanes (C11 – C13) and postulated biomarker, drimane. These low molecular weight compounds, with the exception of drimane, are suspected components of residual naphtha, and the large variabilities in concentration are suggestive that these species may be linked with fluctuating inputs and/or sorption of naphtha to the organic phase of the FFT. Equally possible, the pronounced variability in the low molecular weight n-alkanes concentrations / Thesis / Master of Science (MSc)

Extraction and production of viscous petroleum or bitumen in Alberta, Canada has rapidly developed in the last 30 years, and in 2022 the average daily production was nearly 4 million barrels/day. As a result of the increased global demand of crude oil and technical improvements in the extraction process of surface mining and in situ technologies, this daily output of crude oil is expected to increase further. Surface mining operations are required to invest and implement long-term reclamation strategies in order to properly reduce/manage the large volumes of oil sands process-affected water (OSPW) and tailings and convert the surrounding mining area into an environment similar to its initial state. Commissioned in late 2012 within Syncrude’s Mildred Lake mining site is Base Mine Lake (BML), the first full-scale demonstration of Water Capped Tailings Technology. This aquatic reclamation environment serves as the first of many oil sands pit lakes proposed in the surrounding region, therefore, it is crucial that a comprehensive assembly of scientific pursuits are incorporated into the monitoring and research programs of BML. The presence of petroleum-associated organic compounds, such as Hydrocarbons and Naphthenic acid Fraction compounds (NAFC), remains a top priority for evaluating how BML meets surface water guidelines, but also plays a larger role in the scientific understanding of how biogeochemical and physical processes can impact the environmental fate and transport of these organic compounds in future oil sand pit lakes. This master’s dissertation is focused on the use of ultra-high resolution mass spectrometry to determine the molecular profile of NAFCs extracted from BML in 2019. In this thesis, electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT ICR MS) was used to investigate: i) how particular experimental variables impact the qualitative measurements of oil sand NAFCs, and ii) the spatial variability of NAFCs within the BML water cap and FFT with the aim of providing novel insights to key biogeochemical processes and potential transport mechanisms for continued NAFC inputs in the water column. / Thesis / Master of Science (MSc)

The computational constitutive Modified Cam Clay Model (MCCM) was developed at Cambridge to study the behavior of clays and has been proven to be effective. In this study, this model is extended to the case of dense sands to analyze the accuracy of the stress-strain behavior. This analysis is based on triaxial test data applied to remolded and compacted sand samples under drained conditions. The laboratory triaxial tests were performed by the Florida Department of Transportation to research the permeability effect in sandy soils compacted up to 95% of maximum unit weight at the optimum moisture content. Each soil sample was tested using different stress paths. In addition, these data were also used to obtain the soil parameters. These soil parameters are used as input data for the Modified Cam Clay Model. Moreover, a computer program in MATLAB was developed based on the MCCM constitutive theory and application in order to predict the stress-strain response for overconsolidated soils under drained condition. Based on observations of the qualitative behavior of these soils, a modification is proposed in this thesis to the original constitutive model to improve the predicted stress-strain behavior. The results of the computer program are typically presented in the deviatoric stress versus shear strain and the stress path plane (deviatoric stress versus mean effective stress). These are the principal plots used for the behavior prediction of soil specimens. Furthermore, the results of the computer program were compared to the laboratory triaxial test data. In general, it is may be concluded that, MCCM with some modification, is applicable to dense sands.