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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)

Surface mining of oil sands results in extensive land disturbance, earth movement and water usage. After mining, the disturbed landscapes must be reconstructed and reclaimed as natural landforms. There are numerous challenges associated with understanding the responses of these landforms over time, including a need to track and characterize water movement through closure landforms to understand the hydrological responses of these landforms over time. This study attempted to use natural stable isotopes of water (δD and δ18O) to identify and characterize source waters from various closure landforms at an oil sands mine site. The study area is Syncrude‟s Mildred Lake mine, an open pit oil sands mine located in northern Alberta. A variety of groundwater, surface water and soil samples from a variety of landforms (overburden dumps, composite and mature fine tailings areas, tailings sand structures and freshwater reservoirs) were collected in an attempt to fully represent the isotopic distribution of waters across the mine site. Laboratory analysis of δD and δ18O was done on all samples. The local meteoric water line first established by Hilderman (2011) was redeveloped with additional precipitation data and calculated to be δD=7.0(δ18O) -18.6‰. A natural evaporation line having a slope of 5.3 was calculated for the mine site with samples collected from three surface water ponds on the mine site. Five primary source waters were identified on the mine site: process affected water/tailings, rainfall, snow, interstitial shale water and Mildred Lake water. It was found that these sources of water generally have unique natural stable water isotope signatures. Process affected water at the site generally had an enriched signature compared to other mine waters. The enrichment was attributed to fractionation from the recycle water circuit and natural evaporation. The characterizations of these source waters were then used in several hydrogeological examples to demonstrate that natural stable water isotopes can be applied to water balance estimates and to identify water movement processes related to closure landforms.

In situ measurements of soil nitrogen dynamics is a potential method for evaluating the health of constructed wetlands following oil sands mining. The objective of this study is to measure and compare the soil nitrogen availability of a reclaimed fen (Sandhill fen) with a nutrient-rich reference fen (Poplar fen) and a nutrient-poor reference fen (Pauciflora fen) in the Athabasca oil sands region of northern Alberta. Total Nitrogen (TN), Nitrate (NO3-) and Ammonium (NH4+) supply rates were determined along wetland hillslope transects using Western Ag Innovations Plant Root Simulator (PRSTM) probes at all three sites in 2014. Net N mineralization, net nitrification and net ammonification were determined simultaneously using the buried polyethylene bag sampling method. Overall, TN supply rates were greatest at the poor fen and least at the constructed Sandhill fen. In contrast, mineralization was greatest at the rich fen but again least at the Sandhill fen. Mineralization at the Sandhill fen was controlled evenly by ammonification and nitrification, whereas the two natural sites were controlled by ammonification. Relatively low N supply rates and mineralization at the Sandhill fen were likely due to lower soil organic matter and limited soil moisture in these newly constructed substrates. Spatial differences along the hillslopes also varied among sites. The Sandhill fen had higher TN supply rates at the upslope positions but no significant differences in net N mineralization rates along the hillslopes. The rich fen also had higher TN supply rates at the upslope but greatest mineralization rates downslope. These results highlight the importance of N storage and transport processes and offer insight into the N status of a constructed fen. / Thesis / Master of Science (MSc)

Fort McMurray has experienced significant environmental disruptions, raising concerns about chemical releases that affect the environment, particularly berries. This thesis explores the relationship between environmental factors and the nutritional quality of pin cherry (Prunus pensylvanica L.F.) and common blueberry (Vaccinium myrtilloides Michx) fruits and soil in Fort McMurray (reclaimed and natural lands). Samples were collected in August 2022 and analyzed for chemicals and quality variables. The results revealed concentration variations among samples, with hydrocarbons higher in reclaimed areas and blueberries than others and soil surpassing those in fruits. Copper and iron in fruits exceeded regulatory limits. A strong association between soil chemicals and alkylated hydrocarbons in fruits explained most differences. Soil trace elements and properties were primary environmental drivers, while hydrocarbons were secondary influencers, evident mainly in reclaimed berry environments. Antioxidant-focused nutritional quality in reclaimed berries was predominantly influenced by these key drivers in soil, requiring consistent monitoring.