Skip To Content

Saline Lake

View Larger Map


Wood Buffalo AB

Baseline hydrogeological regime at the intermediate scale AOSTRA Underground Test Facility

Year: 1992

This report presents the baseline hydrogeological regime of formation waters in the Phanerozoic sedimentary succession in an area of approximately 4000 km� (5x8 townships) surrounding the Alberta Oil Sands Technology and Research Authority (AOSTRA) Underground Test Facility (UTF) near Fort McMurray in northeast Alberta. The study was prompted by the AOSTRA plans to expand the Underground Test Facility to a pilot operation. As part of this expansion, it is envisaged to dispose of residual waters by on-site deep well injection. Environment Canada and the Alberta Research Council initiated in 1990 a collaborative study on the effects of deep injection of residual water at the UTF site, with data support and cooperation from AOSTRA. The evaluation of the effects of deep injection of residual water is based on predictive modeling, which requires knowledge of the initial baseline hydrogeological conditions. Previous regional-scale studies of the hydrogeological regime in the sedimentary succession in northeast Alberta are too coarse for the resolution needed for predictive modeling at the UTF site. On the other hand, the data are very scarce and incomplete at the local scale. Thus, an intermediate-scale hydrogeological study is required for the identification and characterization of the hydrostratigraphic units at the UTF site, which form the content of this report. The intermediate-scale hydrostratigraphy around the UTF site is less complex than at the regional scale because of the absence of Lower Elk Point Group halite beds and of extensive pre-Cretaceous erosion of Devonian strata. The sedimentary succession can be broadly divided into four main flow units (aquifers) separated by three barriers (aquitards or aquicludes). The flow of formation waters in the lowermost unit, the Winnipegosis-Basal aquifer, is regional in nature. The formation waters are very saline, with depth related trends. The halite and shale Prairie-Watt Mountain aquiclude separates this aquifer from the Beaverhill Lake aquifer above, which exhibits local flow regime characteristics. The formation water salinity is much fresher, and the flow directions are toward the northeast where the formation waters discharge at outcrop along the Athabasca River and its tributaries. The McMurray-Wabiskaw aquifer also has local flow-regime characteristics, being controlled by the topography and physiography of the area. The bitumen-saturated sands at the McMurray Formation seem to form a strong barrier, separating the flow systems in the Beaverhill Lake below and McMurray-Wabiskaw above, respectively. The shale Clearwater aquitard, overlying the McMurray-Wabiskaw aquifer, appears to be a strong barrier to flow. However, its integrity in places may be questionable because of recent and present-day erosion. The post-Clearwater aquifers of Grand Rapids and Pleistocene strata are of limited extent, with paleo-valleys cutting down in places into the Clearwater aquitard.

Depositional facies and carbonate diagenesis of the downslope reefs in the Nisku Formation (U. Devonian), central Alberta, Canada

Author(s): Anderson, J. H.

Year: 1985

The Nisku Formation (Frasnian) in Alberta was deposited during four stages of basin infill, corresponding to deposition of the Lobstick, Bigoray, Cynthia, and Wolf Lake members. Stages are regionally correlatable, and are bounded by shaly carbonates. Lobstick and Bigoray carbonates were deposited on a ramp in moderate water depths. Rises in sea level resulted in the backstepping of Bigoray carbonate deposition higher onto the ramp and the formation of a shelf margin. Coral mounds formed downslope in water depths of around 50 m. Argillaceous carbonates of the Cynthia and Wolf Lake members infilled the basin between the reefs. Reefs average 2 km in diameter and 100 m in thickness, and exhibit an overall shoaling-upward sequence. The tops of some reefs were subaerially exposed, resulting in the formation of shallow meteoric lenses and minor calcite dissolution and cementation. Reef growth was terminated by drowning. Marine diagenesis included micritization and extensive cementation by Mg-calcite with inclined extinction. Calcic dolomite formed penecontemporaneously with deposition at the tops of the reefs. Following deposition and through the Mississippian, the reefs were buried to depths of 0.5 to 1 km. Stabilization of marine precipitates and precipitation of minor amounts of calcite cement occurred in seawater modified during burial at elevated temperatures. An active hydrologic system developed during the Pennsylvanian and through the Early Cretaceous in response to the westward tilting of the craton. Replacement of limestone by fabric-selective and nonfabric-selective dolomite and calcite dissolution occurred at depths of 0.5 to 1 km and temperatures around 5(DEGREES)C. Magnesium was derived from updip migrating, burially modified seawater. Mass balance calculations indicate that insufficient connate fluid existed in the basin, and in order to dolomitize the reefs and platforms, regional recharge of seawater must have occurred. Thermal convection is proposed as the driving mechanism for this recharge. Baroque dolomite, calcite, and anhydrite formed during deep burial from saline brines during the Late Cretaceous and Early Tertiary. Carbon isotopic data indicate a rock-buffered carbon system. Progressively later calcites and dolomites are depleted in ('18)O and enriched in ('87)Sr because of increasing burial temperatures and increasing reaction of detrital silicates. The susceptibility of these carbonates to burial modification is attributed to deposition in a downslope setting with little early meteoric alteration.

Emergent plant communities of oxbow lakes in northeastern Alberta: Salinity water-level fluctuation and succession

Author(s): Lieffers, V. J.

Year: 1984

Emergent vegetation was sampled in 15 oxbow lakes in a 50-km segment of the Athabasca River in northeastern Alberta. Cover of individual species was visually assessed in plots at the outer, middle, and (or) inner edge of the emergent zone of each lake ( n , 37 sample units). Detrended correspondence analysis showed two main axes of variation. The first axis related to salinity. Water conductivity ranged from 170to 12200 pS cm-' and community types ranged from freshwater fens to saline wetland communities dominated by Scolochloafestucacea, Scirpus maritirnus, and Triglochin maritima. The second axis of variation related to water-level fluctuations. Half of the lakes had an increase in water level in the recent past (ca. 6-30 years). In these lakes, Typha latifolia was dominant in both grounded and floating substrates subjected to increased water levels. Sedge communities dominated by Carex rostrata, C . aquatilis, and Acorus calanzus were common in sites with stable water levels. In freshwater lakes, floating substrates were established over open water by the lateral growth of floating stems of Calla pal~tstrisand Potentilla palustris. Floating substrates were not in the saline sites probably because these open-water colonizers were not present under saline regimes.

Evolution of the hydraulic conductivity of reclamation covers over sodic/saline mining overburden

Year: 2011

The evolution of the field saturated hydraulic conductivity of four covers located on a reclaimed saline-sodic shale overburden from oil sands mining is presented. Three covers consisted of a surface layer of peat/glacial topsoil over a mineral, soil. and one cover was a single layer of mixed peat and mineral soil. Measurements of the field saturated hydraulic conductivity of the cover and shale materials were made with a Guelph permeameter between 2000 and 2004. The hydraulic conductivity of the cover materials in the multilayered covers increased by one to two orders of magnitude over the first few monitoring seasons. The hydraulic conductivity of the single-layer cover system, which was placed three years before the multilayered covers, marginally increased from 2000 to 2002 and then remained relatively unchanged. The hydraulic conductivity of the shale underlying all four covers increased approximately one order of magnitude. Soil temper- ature measurements indicated that one freeze/thaw cycle occurred each year within all cover soils and the surficial overburden. This suggests that freeze/thaw effects were the cause of the observed increases in hydraulic conductivity, as previously observed by other researchers working on compacted clays.

Ground penetrating data radar (GPR): A new geophysical methodology used to investigate the internal structure of sedimentary deposits (field experiments on lacustrine deltas)

Author(s): Jol, H. M.

Year: 1993

Although in its infancy, ground penetrating radar (GPR) is rapidly emerging as a geophysical technology with many possible applications. To assess whether GPR could become a useful tool to investigate internal sedimentary structures, GPR field experiments were conducted on several modern, Holocene and Pleistocene lacustrine deltas to better understand the internal stratigraphy. A pulseEKKO$\sp{\rm TM}$ IV radar system was used with 25, 50, 100 and 200 MHz frequency antennae and 400 and 1000 V transmitter power levels. For most surveys one metre steps (station spacing) were used to provide detailed horizontal resolution of the sedimentologic structures. The profiles were processed and plotted (wiggle trace format) using pulseEKKO$\sp{\rm TM}$ IV software. Depth of reflections was determined from using the common midpoint (CMP) method. Experiments with different antennae frequencies and transmitter powers showed significant variations in vertical resolution, depth of penetration and continuity of reflections. Radar stratigraphic (facies) analysis of GPR profiles, evolved as a secondary development in this dissertation, provided identification of three deltaic types: (1) fan-foreset, (2) wave, and (3) braid. These deltaic types are in general agreement with existing concepts. Fan-foreset deltas are dominated by steeply dipping (25$\sp\circ$) reflections, sandwiched by surface and basal radar facies which have slightly inclined or horizontal reflections. Wave deltas have low-angle inclined reflections capped by discontinuous, wavy reflections. Braid deltas have distinct, continuous and semi-continuous, wavy reflections, often overlying a basal, horizontally continuous reflection, below which an abrupt signal loss occurs. As well, two post depositional features found in deltaic environments were investigated: (1) a potential failure plane and (2) a peatland. The insights gained from the radar stratigraphic analysis of deltaic environments may be extended to the interpretation of seismic records and ancient deltaic systems. More importantly, this information will provide a better understanding of the internal structure which will aid earth scientists in the interpretation of deltaic sequences from drill cores. GPR was found to be most effective (resolution and depth of penetration) in dry and/or wet (freshwater), quartzose-rich, clean (no clay) sand and gravel deposits. The technique does not work well in sediments with silt, clay, caliche (CaCO$\sb3$, calcrete), or saline ground water which attenuate the electromagnetic signal.

Hydrochemistry of Phanerozoic Strata northeast Alberta

Author(s): Hitchon, B.

Year: 1991

The Northeast Alberta study area is defined as 55� to 58�N, and 110� to 114� W. A total of 2933 formation water analyses from the area were entered into the Alberta Geological Survey Well Data Base, verified, and subjected to a variety of electronic, manual-electronic and manual culling to leave a final data base of 525 analyses on which this study was based. Salinity ranges from freshwater to 325,000 mg/l, and there are corresponding maximum contents of Cl (200,000 mg/l), Ca (40,000 mg/l) and Mg (8000 mg/l). Nine maps illustrate the distribution of salinity, which is essentially depth (temperature) related except where there is incursion of fresher waters from overlying aquifers. Sulfate is high (500-5500 mg/l) in aquifers in which anhydrite is present (Elk Point hydrostratigraphic unit -- Prairie Formation; Beaverhill Lake aquifer -- Fort Vermilion Formation; and Grosmont aquifer -- Hondo Formation). Formation waters in the Elk Point hydrostratigraphic unit from near the updip solution edge of the Prairie aquiclude (halite) are similar to those of saline springs in the valley of the Athabasca River, which have been shown to originate from solution of evaporites by meteoric water. Based on the composition of their formation waters the aquifers can be combined into groups separated by aquitards, as follows: Viking aquifer (weak Joli Fou aquitard); Grand Rapids aquifer (strong, regional Clearwater aquitard); Clearwater, Wabiskaw and McMurray aquifers; Wabamun and Winterburn aquifers (weak Upper Ireton aquitard); Grosmont aquifer (strong Lower Ireton aquitard); Beaverhill Lake aquifer (significant, regional Prairie aquiclude); Elk Point hydrostratigraphic unit (mainly Keg River aquifer); Precambrian aquiclude. In summary, the formation waters of the Northeast Alberta area are an extension of those in the adjacent Peace River Arch area, exhibit similar characteristics, and have similar origins.

Hydrological modelling of reconstructed watersheds using system dynamics

Author(s): Elshorbagy, A., & Jutla A.

Year: 2006

The mining of oil sands in the sub-humid region of Northern Alberta, Canada causes large-scale landscape disturbance, which subsequently requires extensive reclamation to re-establish the surface and subsurface hydrology. The reconstructed watersheds examined in this study are located at the Syncrude Canada Limited mine site, 40 km North of Fort McMurray, Alberta, Canada. The three experimental reconstructed watersheds, with nominal soil thicknesses of 1.0 m, 0.50 m and 0.35 m comprised a thin layer of peat (15-20 cm) over varying thicknesses of secondary (till) soil, have been constructed to cover saline sodic overburden and to provide sufficient moisture storage for vegetation while minimizing surface runoff and deep percolation to the underlying shale overburden. In order to replicate the hydrological behavior, assess the sustainability, and trace the evolution over time of the reclaimed watersheds, a suitable modeling tool is needed. In this research, a model is developed using the system dynamics approach to simulate the hydrological processes in the three experimental reconstructed watersheds and to assess their ability to provide the various watershed functions. The model simulates the vertical and lateral water movement, surface runoff and evapotranspiration within each watershed. Actual evapotranspiration, which plays an important role in the hydrology of the Canadian semi-arid regions, is simulated using an indexed soil moisture method. The movement of water within the various soil layers of the cover is based on parametric relationships in conjunction with conceptual infiltration models. The feedback relationships among the various dynamic hydrologic processes in the watershed are captured in the developed System Dynamic Watershed Model (SDWM). Most hydrological models are evaluated using runoff as the determining criterion for model calibration and validation, while accounting for the movement of moisture in the soil as a water loss. Since one of the primary objectives of a reconstructed watershed is to maintain the natural flora and fauna, it is important to recognize that soil moisture plays an important role in assessing the performance of the reconstructed watersheds. In turn, soil moisture becomes an influential factor for quantifying the health of the reconstructed watershed. The developed model has been calibrated and validated with data for two years (2001-2002), upholding the sensitive relationship between soil moisture and runoff. Accurate calibration of the model based on simulations of soil moisture in the various soil layers improves its overall performance. The model was subsequently used to simulate the three sub-watersheds for five years, with changing the calibrated model parameters to use them as indicators of watershed evolution. The simulated results were compared with the observed values. The results of the study illustrate that all three watersheds are still evolving. Failure to identify a unique parameter set for simulating the watershed response supports the hypothesis of watershed evolution. Soil moisture exchange between the till and peat layers changed with time in all of the watersheds. There was also a modest change in the water movement from the till to shale layers in each of the sub-watersheds. Vegetation is increasing in all of watersheds although there is an indication that one of the sub-watersheds may be sustaining deep rooted vegetation. The results demonstrate the successful application of the system dynamics approach and the developed model in simulating the hydrology of reconstructed watersheds and the potential for using this approach in assessing complex hydrologic systems. Degree:

Paleosalinity reconstructions using diatoms from lakes in western Canada

Author(s): Wilson, S. E.

Year: 1996

Long-term climatic records are not available from instrumental data, and so proxy data are required to infer long-term climatic trends. The sedimentary records of closed-basin lakes in arid and semi-arid regions are particulary good archives of paleohydrological and paleoclimatic signals as lake levels are governed largely by the balance between precipitation and evaporation. In Canada, little is known of the enviromental and climatic histories of arid regions such as the Great Plains and the southern interior of British Columbia. In order to provide a quantitive means of evaluating fluctuations in salinity, and potentially climate, a diatom-based salinity transfer function (r$\sp2$ = 0.87, bootstrap RMSE = 0.37) was developed to infer past salinities and climatic trends from fossil diatom assemblages preserved in lake sediment cores from closed-basin lakes in western Canada. The modern diatom assemblages and limnological data were collected from 208 fresh and saline lakes from the southern Interior of British Columbia and from 11 saline lakes from the northern Great Plains. This dataset is an expansion of an earlier dataset of 102 lakes. Evaluation of dataset size and species deletion criteria using this 219 lake dataset emphasizes the value of constructing calibration sets with a large number of lakes and many taxa to provide better estimates of species optima and tolerances to various enviromental variables, such as salinity, and to provide more and closer modern analogues for inferring salinity downcore. Using the above salinity transfer function, Holocene salinity changes were reconstructed for Harris Lake, in the Cypress Hills of Saskatchewan, and from Clearwater Lake, Saskatchewan. The diatom paleosalinity record from Harris Lake indicated that the lake remained fresh throughout the Holocene, even when many closed-basin lakes in the surrounding plains experienced higher salinities during the warmer early Holocene. The diatom data contradict an earlier geochemical study that suggested episodes of hypersalinity in the early Holocene. A high-resolution early Holocene diatom record from Clearwater Lake revealed that the lake had much higher salinities ($\rm {>}20 g\cdot L\sp{-1}$) between 9700-8840 years BP, compared to the present ($\rm {\sim}1 g\cdot L\sp{-1}$. It is unclear whether this high salinity period was the result of evaporative stress caused by increased summer insolation, as suggested by Milankovitch cycles, or was the result of changes in groundwater flow to the lake. The diatom-inferred salinities clearly showed that Clearwater Lake had become fresh by ca. 7300 BP. The more recent diatom record from Clearwater Lake shows that the lake is not particulary sensitive to short-term climatic fluctuations, although it appears to show signs of responding to at least some known droughts of the recent past.

Response of confined aquatic biota to mine depressurization water in Beaver Creek Reservoir

Year: 1980

Beaver Creek Reservoir was formed as a result of diverting the natural flow of Beaver Creek away from mine and plant areas and southward to the Athabasca River via Poplar Creek. The diversion was initiated in the fall of 1975 with the closure of the Beaver Creek Dam; filling of the reservoir was completed in the spring of 1976. When it became necessary to remove mine depressurization water from the mining area, Syncrude was granted permission by the Government of Alberta to discharge this effluent into Beaver Creek Reservoir, on the condition that chloride levels in water entering Poplar Creek did not exceed 400 mg/L above ambient levels. The present study was designed to investigate the survival of selected organisms in Beaver Creek Reservoir during 1979. The primary objective was to determine the response of selected species of aquatic biota to saline mine depressurization water after average dilution in the Beaver Creek Reservoir. More specific requirements of the study were: a) the study was to be carried out entirely within the Beaver Creek Reservoir using test organisms held in situ; b) the study must include three sampling locations and three replicates of each test organism at each station; c) test organisms must include: periphyton (on artificial substrates), native species of fish (white sucker and fathead minnow), and native species of invertebrates (either Gammarus or Hyalella); and d) field studies were to be conducted between June and October, 1979 and were to examine both short and long term effects.

Root distribution activity and development for boreal species on reclaimed oil sand mine soils in Alberta Canada

Author(s): Lazorko, H. M.

Year: 2008

Alberta’s oil sands are located in the boreal forest where surface mining disturbs huge tracts of land. One such area, Syncrude Canada Ltd.’s Mildred Lake mine, contains waste overburden (OB) piles which can be saline and sodic (SSOB). The objectives of this research were to 1) determine SSOB material impacts on planted tree root distributions, 2) quantify root activity to identify plant species growing at depth, and 3) document coarse woody root structure for planted trees. Root distributions for three mixedwood stands on reclaimed OB in relation to electrical conductivity (EC) and sodium absorption ratio (SAR) were examined using soil cores. Root distributions followed a similar pattern with soil depth as those from undisturbed boreal forest stands and appeared unaffected by the SSOB at this stage; however, future monitoring will be required as the stands mature. Root activity was assessed for jack pine (jP) and white spruce (wS) stands on tailings sand (TS) and OB using a strontium (Sr) chloride tracer. Understory and tree foliage was collected prior to and after application to measure Sr concentration in the control, broadcast, and depth treatments. A small proportion of roots grew in the OB material regardless of its chemical properties. Results from the Sr tracer study suggested that these roots were probably from the clover, sow thistle, and grasses. Planted trees showed little to no change in Sr tissue content suggesting that there were little to no roots in the treatment zones, the understory species out-competed the trees for Sr accessibility, or the tracer was diluted in the tree biomass to undetectable levels. Root systems of planted jP trees older than 10 years and older than 20 years on TS and OB were excavated and the number and diameter of lateral roots, the degree of kinking and coiling, and the presence of a taproot were recorded. Excavated trees showed poor taproot development on 70% of the trees and numerous root deformities, suggesting that more emphasis is needed in correct planting techniques and good planting stock to ensure proper root development. Roots are critical components of boreal forest ecosystems; without healthy root systems productivity may decline, stands may be susceptible to windthrow, and general forest health may suffer.

Species distribution and habitat relationships of waterfowl in northeastern Alberta

Author(s): Hennan, E., & Munson B.

Year: 1979

The objective of the waterfowl segment of the AOSERP/Avifauna program consisted of determining waterfowl species abundance and diversity and habitat associations. During waterfowl aerial surveys the length of wetland edge surveyed in 1976 ranged from 373 to 453 km on 65± wetlands. Spring-staging totals for two surveys for this year were 1000 and 3600 ducks. Breeding-pair totals for three surveys ranged from 540 to 870. Two brood surveys revealed 225 and 463 broods; 3590 and 9318 moulting ducks were counted coincidentally. Five fall-staging surveys revealed a total of from 11 000 to 24 000 ducks. Aerial surveys conducted in 1977 were reduced in number and scope with less than half the number of wetlands surveyed in six surveys. Oil sands wetlands were more heavily utilized by diving than dabbling ducks. Analysis of variance for edge type/habitat next-to-edge combinations for diving and dabbling ducks revealed significant associations for both groups of ducks for breeding pairs: dabblers preferred emergent vegetation edge combined with a shrub habitat next-to-edge. Divers preferred, with decreasing preference: emergent vegetation/shrub, wet meadow/coniferous forest, emergent vegetation/wet meadow, and emergent vegetation/mixed forest. Analysis of spring-staging flocks of both dabblers and divers revealed some preferred habitat associations but those did not prove significant. Brood and moulter data showed no significant habitat relationships. Fall-staging divers exhibited significant relationships preferring: open water, shrub/shrub, flooded trees/mixed forest, emergent vegetation/shrub, and shrub/mixed forest. Fall-staging dabblers exhibited habitat preferences but these were not significant. The preferred wetlands types, in descending order, were: lakes with shallow-marsh aquatics, lakes with deep-marsh aquatics, open lakes, creeks, and rivers. The significance of individual wetlands in terms of duck numbers and densities varied throughout the season. However, certain wetlands appeared consistently important: Little McClelland Lake, West Muskeg Lake, Wood Slough, Gordon Lake, Saline Lake, and Algar Lake.

The design and installation of a field instrumentation program for the evaluation of soil-atmosphere water fluxes in a vegetated cover over saline/sodic shale overburden

Author(s): Boese, C. D.

Year: 2003

The mining of oil sands near Fort McMurray, Alberta, involves the stripping of salinesadie overburden to gain access to the oil-bearing formation. The overburden is placed in mined out pits and surface dumps and is re-contoured before being capped with a mandated 1 m soil cover. The potential for slope instability, subsidence, and salinization resulting from the character of the saline-sodic material and its interaction with fresh water makes it imperative that the amount of precipitation percolating below the root zone be minimised. Syncrude Canada Ltd is conducting a large scale cover trial at the Mildred Lake mine in order to assess the performance of different reclamation strategies. Four 1 hectare prototype covers were placed on an area referred to as the SW30-Dump in order to study the basic mechanisms controlling moisture movement within the cover systems. Three covers were constructed in 1999 with configurations of 1.00 m, 0.50 m and 0.35 m thick and consisted of a thin layer of peat overlying varying thickness of secondary soil. A fourth study site was established on a recently reclaimed watershed capped with a 1.00 m cover of peat/secondary mix in 1996. A field instrumentation program was carried out consisting of detailed monitoring of matric suction, volumetric water content and temperature within the different soil profiles, as well as measurements of runoff, interflow and site-specific meteorological conditions. Generally, all instrumentation performed well and was found to correctly measure the soil-atmosphere fluxes required to assess each cover alternative. Evaluation of the covers revealed that the 1m layered cover was the only one to maintain sufficient soil moisture for all monitored growing seasons. A significant portion of the available soil water was held within the peat layer. The other three covers lacked the required storage during drier periods and on numerous occasions soil suction values exceeded the wilting point

The environmental hydrogeology of the oil sands lower Athabasca area, Alberta

Author(s): Miall, A. D.

Year: 2013

Shallow fresh groundwater and deep saline groundwater are used together with surface water in the extraction of bitumen from the Athabasca Oil Sands both in the surface mining and in situ operations. However, increasing efficiencies in processing technologies have reduced water use substantially, and currently at least 75% of the water used in most operations is recycled water. Much concern has been expressed regarding contamination of surface waters by seepage from tailings ponds, but hydrogeological studies indicate that this is not happening; that seepage capture design is effective. Oil sands mining and in situ project licensing and operation regulations include Environmental Impact Assessments that mandate considerable hydrogeological measurement and monitoring work. However, little of this is independently evaluated for accuracy or synthesized and interpreted for the public. Recent changes in Alberta environmental regulation, including the establishment of the Alberta Environmental Monitoring Management Board (in October 2012) are expected to bring new transparency to environmental management of Oil Sands operations.

Toxicity of saline groundwater from Syncrude's lease 17 to fish and benthic macroinvertebrates

Author(s): McMahon, B.

Year: 1977

The mining of the tar sands which are included in the area to be developed by Syncrude Canada Ltd. will require the dewatering of the mine pits. This will involve the pumping of large volumes of saline groundwater. Present plans call for its eventual disposal through Ruth Lake, the Poplar River and, finally, the Athabasca River. This study was designed to determine whether groundwater from the mine area is toxic to aquatic organisms and, if so, the concentrations at which this toxicity is expressed. A variety of species, including both fish and aquatic insects, was tested to determine the range of sensitivity among aquatic animals. The resultant data can, with some qualifications, be used to estimate the maximum safe concentrations of groundwater which can be added to natural waters with minimal risk of toxic effects.

Water use in Canada's oil-sands industry: The facts

Author(s): Lunn, S.

Year: 2013

Canada's oil-sands industry is often perceived as having poor environmental performance. One focus area is the use of water for oil-sands production. Bitumen from oil sands is produced by surface mining or by in-situ thermal extraction. Both technologies are water-based. The oil-sands deposits are situated in northern Alberta, where the river basins have 87% of the provincial average annual water supply but only have 13% of the demand. Oil-sands operators have made significant progress in improving freshwater use productivity (intensity), and water use represents a small percentage of natural supply. For in-situ production, the 2010 freshwater use productivity for the industry was 0.43 units of freshwater per unit of bitumen produced. As an example of continuous improvement, the Imperial Oil Cold Lake in-situ oil-sands operation has improved freshwater use productivity by 90% since 1985 through produced-water recycling and the use of deep saline groundwater. The in-situ oil-sands industry will remain a relatively small water user into the future (2030) using an estimated 0.04 to 0.09% of available supply from the three river basins where it is situated. For oil-sands mining, most of the source water comes from the Athabasca River. The average water-use productivity for oil-sands production between 2006 and 2011 was 2.5 units of Athabasca River water per unit of bitumen and synthetic crude oil produced (3.6 for all freshwater sources). In 2011, the oil-sands mining industry used 0.54% of the annual Athabasca River flow and 3% of the lowest 2011-2012 winter weekly flow. For growth forecasts to 2030, it is estimated that the oil-sands mining industry will require 1.4% of the average annual flow of the Athabasca River. Overall, by 2030, it is projected that the entire oil-sands industry will use less than 0.4% of Alberta's average annual water supply to produce 80% of Canada's total oil production.

Zooplankton communities and genetic divergence of rotifers in saline and subsaline lakes

Author(s): Derry, A. M.

Year: 2001

Although salinity and aquatic biodiversity are inversely related in lake water, the relationship between types of salts and zooplankton communities is poorly understood. Further, there is no information on whether variation in salt concentration contributes to the genetic divergence of zooplankton populations. In my study, lake water dominated by chloride anions had distinct zooplankton communities from those dominated by sulphate/carbonate anions. This distinction likely resulted from the combined effects of contrasting water chemistries and predation regimes. Greater haplotype diversity and genetic divergence was observed among populations of halophilic Brachionus plicatilis than among populations of predominantly freshwater Keratella quadrata rotifers. The most divergent B. plicatilis population was a strain that was most abundant at lower salinities. I provide preliminary evidence for an additional sibling species in the B. plicatilis species complex. This study documents some of the first molecular phylogenetic work conducted on rotifers.