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A first approximation kinetic model to predict methane generation from an oil sands tailings settling basin

Year: 2008

A small fraction of the naphtha diluent used for oil sands processing escapes with tailings and supports methane (CH4) biogenesis in large anaerobic settling basins such as Mildred Lake Settling Basin (MLSB) in northern Alberta, Canada. Based on the rate of naphtha metabolism in tailings incubated in laboratory microcosms, a kinetic model comprising lag phase, rate of hydrocarbon metabolism and conversion to CH4 was developed to predict CH4 biogenesis and flux from MLSB. Zero- and first-order kinetic models, respectively predicted generation of 5.4 and 5.1 mmol CH4 in naphtha-amended microcosms compared to 5.3 (±0.2) mmol CH4 measured in microcosms during 46 weeks of incubation. These kinetic models also predicted well the CH4 produced by tailings amended with either naphtha-range n-alkanes or BTEX compounds at concentrations similar to those expected in MLSB. Considering 25% of MLSB’s 200 million m3 tailings volume to be methanogenic, the zero- and first-order kinetic models applied over a wide range of naphtha concentrations (0.01–1.0 wt%) predicted production of 8.9–400 million l CH4 day−1 from MLSB, which exceeds the estimated production of 3–43 million l CH4 day−1. This discrepancy may result from heterogeneity and density of the tailings, presence of nutrients in the microcosms, and/or overestimation of the readily biodegradable fraction of the naphtha in MLSB tailings.

A review and assessment of the baseline data relevant to the impacts of oil sands developments on large mammals in the AOSERP study area

Year: 1979

The available baseline data which are relevant to the documentation and evaluation of the impacts on large mammals (moose, woodland caribou, wolf) which would result from oil sands development are reviewed. An approach to the analysis of impacts was developed to provide a logical framework for the determination of what types of baseline data were relevant to the objectives of study. Baseline data for each species were discussed under three categories: seasonal population dispersion, the potential impacts of large development projects, and population dynamics. The review forms the basis of the evaluation of the state of baseline knowledge of large mammals in the AOSERP study area and a statement of the research which should be completed in order to provide the data. A critique of the state of the baseline knowledge of large mammals (moose, woodland caribou, wolf) was conducted with the objectives being to determine whether or not baseline knowledge of these species is adequate to assess the impacts of large developments on large mammal populations in the AOSERP study area, and to identify specific knowledge gaps. Major gaps in the baseline knowledge of moose were: seasonal habitat use, the effects of sensory disturbances and population density; a minor gap was identified in the knowledge of the effects of development on direct mortality of moose. Major gaps in the baseline knowledge of woodland caribou were: distribution on the AOSERP study area, seasonal habitat use, the effects of sensory disturbance, and population density; minor gaps were identified in the knowledge of the effects of development on direct mortality of woodland caribou. Major gaps in the baseline knowledge of wolf were: seasonal habitat use and population density; minor gaps were identified in the knowledge of the seasonal movement patterns, the effects of sensory disturbances, and the effects of development projects on direct mortality of wolves.

A statistically derived forecast scheme for winds and temperatures in the Athabasca tar sands area

Author(s): Hansen, M. C., & Leahey D. M.

Year: 1982

Syncrude Canada Ltd. operates an oil sands extraction plant in the Athabasca Tar Sands region of northeastern Alberta. Although this facility is designed to maintain resulting ground level air quality within the objectives of Alberta Environment, exceedances of these objectives may occur in extreme meteorological conditions. If these conditions were to be predicted in advance, then plant emissions could be adjusted in order to maintain ground level air quality at a desirable level. The purpose of this study is to develop a forecast scheme, based on analysis of historical, site specific data, which will allow prediction eight hours in advance of real time of those parameters which are required to predict ground level air quality. Specifically, these predictands are: wind speed and direction at stack and plume heights, vertical temperature gradient at stack height, mixing height and horizontal fluctuations of wind direction. Development of the forecast scheme for predictands relating to wind and temperature employed multiple linear regression analyses. Historical data for these parameters were obtained from analysis of 2 399 pibal observations and 2 289 minisonde observations made near the Syncrude plant site over the years 1975 to 1979 inclusive. Concurrent data for the predictors used in the regression equations were obtained from the following national, regional and local sources: the 850 mb pressure level wind field prepared by the Canadian Meteorological Centre (CMC), radiosonde temperature profiles obtained at Fort Smith and Stony Plain, upper air wind profiles and hourly surface records from the Fort McMurray airport, winds and the temperatures from the Tall Tower, and finally, surface winds from the towers at Stony Mountain and Mildred Lake.

A study of the chemical and physical properties of Syncrude's tailings pond, Mildred Lake 1980

Author(s): MacKinnon, M. D.

Year: 1981

Syncrude Canada Ltd. is producing synthetic crude oil from a surface mine in the Athabasca Tar Sands area of north-eastern Alberta. This report describes the chemical and physical properties in the tailings pond at the Mildred Lake site of Syncrude Canada Ltd. during the ice-free period of 1980. Syncrude's Environmental Research Monographs are published verbatim from the final reports of professional environmental consultants. Only proprietary technical or budget-related information is withheld. Because we do not necessarily base our decisions on just one consultant's opinion, recommendations found in the text should not be construed as committments to action by Syncrude.

A study to evaluate the performance of reclamation soil covers placed over an oil sands fluid coke deposit

Author(s): Fenske, D.

Year: 2012

Coke, a by-product of petroleum extraction from oil sands, is considered a potential energy source and must be stored within the reclaimed landscape in a manner that allows it to be recovered in the future. Syncrude Canada constructed two instrumented watersheds at the Mildred Lake Settling Basin (tailings management facility) to study the effects of coke in the environment. The watersheds consisted of a “shallow” and a “deep” cover system with nominal thicknesses of 35cm and 100cm, overlying an approximate 5 m thick coke deposit. The two reclamation soil covers were constructed using peat-mineral mix placed over secondary (glacial till). The global objective of this research program was to evaluate the preliminary performance for each of the soil covers with respect to the available water holding capacity (AWHC). The specific objectives were to: a) install additional instrumentation to supplement the existing instrumented watersheds; b) characterize the properties of the covers on each watershed; and c) develop a preliminary, one-dimensional water balance for each watershed. Existing instrumentation on each cover (installed by others) included: a meteorological station; automated soil stations to monitor suction, water content and temperature; and, lysimeters to collect net percolation. Additional instrumentation was installed during this research program to track vertical and horizontal variations in soil conditions and included: access tubes for monitoring water content; temperature sensors; gas sampling points; and, standpipe piezometers to determine depth to the water table. The instrumentation generally performed well, with the exception of the lysimeters which did not appear to measure net percolation accurately. Through the measurement of soil parameters, interpretation of field monitoring data and laboratory testing, the covers were characterized for their relative ability to store water for plant growth. A water balance was determined for each watershed. Evaluation of the covers indicated that neither the deep nor the shallow covers were successful at storing sufficient water necessary for plant growth under dry conditions. However, the deep cover performed better than the shallow cover based on the overall cover performance, likely due to its higher AWHC.

Acute toxicity of oil sands wastewater: A toxic balance

Year: 1994

A study was conducted to identify and determine the relative importance of the acutely toxic fractions of wastewater from oil sands extraction using a bioassay directed toxicity identification evaluation (TIE), to use these data to construct a toxic balance, and to determine whether the same fractions were acutely toxic to Microtox, Daphnia, and rainbow trout. Samples of extraction wastewater were obtained from the Mildred Lake tailings pond in Alberta during summer 1991 and 1992. The samples were centrifuged to remove suspended solids and the toxicity of the supernatant was evaluated. Seven manipulations, each of which was designed to remove a different class of compounds, was performed on the supernatant samples. A complete TIE was performed using the Microtox bacterial bioassay. All acute toxicity of the surface tailings pond water to Microtox was removed by precipitation of organic acids or by removal of nonpolar organics. These results suggest that the main toxic fraction was a surfactant. In the interstitial water of the fine tails, volatiles accounted for 15% of the acute toxicity. However, all the acute toxicity of interstitial water was removed by precipitation of organic acids or by removal of nonpolar organics. Organic acids accounted for all the acute toxicity of tailings pond water to Daphnia and rainbow trout. Differences in relative sensitivity of test organisms to the toxic fraction demonstrate the importance of using more than one test organism to evaluate acute toxicity. Daphnia was 0.4 times less sensitive and rainbow trout 3 times more sensitive than Microtox. 20 refs., 6 tabs

An evaluation of the use of natural stable isotopes of water to track water movement through oil sands mine closure landforms

Author(s): Baer, T. J.

Year: 2014

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.

Analysis of methanogenic microbial communities from oil sands processing tailings

Author(s): Penner, T. J.

Year: 2006

Tailings management in the oil sands industry aims to increase the rate of densification of fine clay and silt particles, releasing pore water for reuse in bitumen extraction and producing mature fine tailings (MFT) for subsequent use in reclamation. Microbial methane production has accelerated densification of the MFT, and acetate amendment may enhance this process. To identify important microorganisms in methane production, 16S rRNA gene sequences were used. At 22°C, methanogenic cultures from acetate-amended or unamended tailings comprised hydrogenotrophic methanogens and clostridial homoacetogens, regardless of acetate amendment. These groups could be participating in syntrophic acetate oxidation. In MFT samples collected from various depths of two active tailings ponds at the Syncrude Canada Mildred Lake site most methanogens were related to acetoclastic Methanosaeta spp. Most Bacteria were related to the Proteobacteria, including sulfate-reducing bacteria and hydrocarbon degraders. Based on these results, a possible pathway for methane production from MFT is proposed.

ANN modeling of ambient particulate matter in Fort McKay, Alberta

Author(s): He, Y.

Year: 2004

Particulate matter with a diameter smaller than 2.5 μm (PM2.5 ) is a key urban air pollutant. Modeling of ambient PM2.5 is considered important for understanding its contribution sources. However, conventional models employing mathematical formulae are difficult to use for modeling ambient PM2.5 because of complexities involved in its formation and behaviour in the atmosphere. Artificial neural network (ANN) is more suited to solving complex non-linear problems associated with formation and behaviour of PM2.5 in the atmosphere. ANN was used to model ambient PM2.5 concentrations at Fort McKay, Alberta in order to examine the potential influence of operations at the Syncrude Canada Ltd. Mildred Lake oilsand facility. Results of ANN modeling were able to demonstrate that changes in ambient PM2.5 concentrations at Fort McKay, Alberta were, in part, due to changes in ambient PM2.5 concentrations observed at the Syncrude facility. ANN showed promise as a tool for predicting ambient PM2.5 concentrations.


Application by Syncrude Canada Ltd. for amendment of Approval No. 7550: Proposed Mildred Lake upgrader expansion

Year: 1999

Syncrude Canada Ltd. applied, pursuant to Section 14 of the Oil Sands Conservation Act, to amend Approval No. 7550 to allow for the expansion of its Mildred Lake upgrading complex, in which the proposed expansion would increase Syncrude's production of marketable hydrocarbons through the addition of a new fluid coker, a flue gas desulphurization unit, new froth treatment facilities, additional hydrotreating and sulphur recovering capabilities and associated ancillary units. Syncrude sought approval for a production scheme for the expanded facilities that would increase annual production volume to 27.5 from 15.3 million cubic m per year of marketable hydrocarbons, and removal of the annual production volume and term limits for the upgrading complex. Under a coordinated application process adopted by Alberta Environment and the Alberta Energy and Utilities Board, Syncrude filed a joint application and environmental impact assessment. It also filed for an amendment to its Approval No. 26-01-00 issued under the Alberta Environmental Protection and Enhancement Act. The issues to be considered with respect to the application are: technology - diluent recovery, bitumen conversion technology selection, and removal of production and term limits; environment - sulphur dioxide emissions from the base plant, sulphur recovery from acid gas, greenhouse gases, nitrogen oxides, particulates, and ozone; and water management - cumulative effects. Considering all the evidence, the Boards. Considering all the evidence, the Board was prepared, with the approval of the Lieutenant Governor in Council, to approve Syncrude's Application No. 980381 with conditions and requirements as referenced in this report and that will be specified in the approval

Assessing accumulation and biliary excretion of naphthenic acids in yellow perch exposed to oil sands-affected waters

Year: 2014

Naphthenic acids are known to be the most prevalent group of organic compounds in oil sands tailings-associated waters. Yellow perch (Perca flavescens) were exposed for four months to oil sands-influenced waters in two experimental systems located on an oil sands lease 30 km north of Fort McMurray Alberta: the Demonstration Pond, containing oil sands tailings capped with natural surface water, and the South Bison Pond, integrating lean oil sands. Yellow perch were also sampled from three lakes: Mildred Lake that receives water from the Athabasca River, Sucker Lake, at the edge of oil sands extraction activity, and Kimowin Lake, a distant reference site. Naphthenic acids were measured in perch muscle tissue using gas chromatography–mass spectrometry (GC–MS). Bile metabolites were measured by GC–MS techniques and by high performance liquid chromatography (HPLC) with fluorescence detection at phenanthrene wavelengths. A method was developed using liquid chromatography–high resolution mass spectrometry (LC–HRMS) to evaluate naphthenic acids in bile. Tissue analysis did not show a pattern of naphthenic acids accumulation in muscle tissue consistent with known concentrations in exposed waters. Bile fluorescence and LC–HRMS methods were capable of statistically distinguishing samples originating from oil sands-influenced waters versus reference lakes. Although the GC–MS and HPLC fluorescence methods were correlated, there were no significant correlations of these methods and the LC–HRMS method. In yellow perch, naphthenic acids from oil sands sources do not concentrate in tissue at a measurable amount and are excreted through a biliary route. LC–HRMS was shown to be a highly sensitive, selective and promising technique as an indicator of exposure of biota to oil sands-derived naphthenic acids.

Athabasca oil sands bibliography (1789 - 1964)

Author(s): Carrigy, M. A.

Year: 1965

The bibliography of the Athabasca Oil Sands published in 1962 as Preliminary Report 62-7 is now out of print. Since its publication so much new work has been published on the oil sands that it seemed desirable to revise the whole report rather than issue a supplement to the 1962 bibliography. The major events contributing to the large increase in volume of literature in such a short time were the filing of applications by several oil companies to the Oil and Gas conservation Board for permits to develop the oil sands commercially and the Second Athabasca Oil Sands Conference which was held in Edmonton on October 30th and 31st, 1963. Also, in 1964 permission was granted to Great Canadian Oil Sands Limited to produce 45,000 barrels of oil per day from Lease 4 at Mildred Lake using a hot-water process. Work at the site is progressing rapidly and the plant is expected to be completed by 1967. This report has two parts; in Part I all of the citations are listed alphabetically under the author's name with full title and publication data; in Part II the same publications are grouped under thirteen subject headings.

Background air and precipitation chemistry

Year: 1978

In March 1976, the first in a series of intensive field studies was carried out in the Alberta Oil Sands Environmental Research Program study area in northeastern Alberta to examine the fine structure of the atmosphere and dispersion characteristics under winter conditions. The study comprised several co-ordinated sets of measurements over a two week period. These included: minisonde flights, tethersonde vertical profiles, acoustic sounder and delta-T sonde profiles, correlation spectrometer and ground level sulphur dioxide measurements, plume rise photography and background air and precipitation chemistry. Plume dispersion measurements made by aircraft were co-ordinated with the study and are reported in a separate publication. All measurements, except those for background air chemistry, were made within 20 km of Mildred Lake taking in the present oil sands processing facility of Great Canadian Oil Sands Ltd. and the future production site of Syncrude Canada Ltd. The study was successful in identifying unique features of the winter environment of the area such as diurnal formation and breakup of inversion layers, the effects of the river valley on circulation patterns, plume characteristics, pollutant deposition patterns in the snowpack and background levels of gases and particulates.

Beaver Creek: an ecological baseline survey

Year: 1973

[Anonymous] (1973).  Beaver Creek: an ecological baseline survey. Environmental Research Monograph 1973-2,

Bison and the oil sands industry

Author(s): Pauls, R. W.

Year: 1999

Many tens of thousands of hectares of forested land will be disturbed and reclaimed in the surface mineable Athabasca oil sands area during the next few decades. The surface area disturbed by Syncrude's Mildred Lake development alone exceeds 10 000 ha to date. It is not clear that reforestation of disturbed areas will best accommodate the aspirations of all stake-holders, particularly traditional users of the land. A five-year research program by Syncrude Canada limited and the Fort McKay First Nations has examined the feasibility of raising bison on land reclaimed after disturbance by oil sands development. Forage productivity and carrying capacity for bison was comparable to that of grasslands elsewhere in Alberta. Concerns regarding compaction of newly rebuilt soil by bison traffic proved unfounded. Bison demonstrated weight gains typical for ranched bison and calving rates averaged 90%, a value typical for ranched bison. The animal husbandry problems encountered were typical of those occurring on bison ranches elsewhere in Alberta. An economic analysis indicates that a 1000 ha bison ranch on reclaimed land has a net present value that compares very favourably with a similar area supporting commercial forest. Subject to approval by Alberta Environmental Protection, the current research project will be expanded as a pilot commercial ranching venture in order to explore its commercial viability as a business venture by the Fort McKay First Nations. At the same time, measures will be implemented to resolve various regulatory issues associated with commercial bison production in the oil sands area.