Contaminant Fate Modelling For The Athabasca River

Describes and presents simulation results from numerical models of the transport and fate of environmental chemicals in northern Alberta rivers. The models were developed using the USEPA WASP modelling system and were structured as one-dimensional (longitudinal) models with separate, interacting water column and bed sediment compartments. Seven selected organic chemicals were simulated over 1992-93 for the Athabasca River and over 1990-91 for the Wapiti/Smoky River system. Chemicals simulated included 2,3,7,8-tetrachloro dibenzofuran, dehydroabietic acid, and phenanthrene. The models were first calibrated for sodium and total suspended solids. Organic chemicals were simulated using a set of environmental fate constants developed from a literature search, numerical estimation software, and estimation from field data. Results of initial simulations were compared to observed data and adjustments made to selected constants to improve the calibration.

Describes and presents simulation results using a revised model simulating the fate of contaminants in the Athabasca River. The revised fate model allows predictive sediment transport simulation within the WASP4 model framework, predicts resuspension from hydraulic information supplied by WASP4 and from user-supplied sediment characteristics, and can be applied to different flow conditions without having to re-describe sediment transport rates. Several simulations were run using input files from the original model calibration. Program listings of subroutines are included.

Describes a study to construct and calibrate a steady-state food chain model to simulate the uptake and bioaccumulation of selected organic chemicals, with different physical and chemical properties, in the mountain whitefish, longnose sucker, and northern pike food web of the Athabasca River. The model is based on the WASP 14, Thomann-Connolly and Gobas food chain models. The modelling effort involved review and interpretation of sediment transport dynamics, contaminant distribution and concentration in sediment, water, and biota, and the refinement of the existing models. Results are presented from model simulations and compared to observed concentrations of such compounds as furans, resin acids, and chlorinated phenolics. The appendix includes a discussion of food chain modelling theory and its application to the present study.

From investigation of lake sediments, chemical species are known to be transported into northern Alberta river basins via atmospheric pathways. This report describes and presents results of a model used to identify the potential atmospheric routes for airborne contaminants to the Athabasca basin. The model used was the Atmospheric Environment Service's Lagrangian back trajectory model. Differences between frequency of air passages among the seasons and continental regions are noted.

Report to the federal ministers of Environment and Indian & Northern Affairs, Alberta's Minister of Environmental Protection, and NWT's Minister of Renewable Resources. Summarises the main scientific findings of the Northern River Basins Study, which was established to examine the relationship between industrial, municipal, agricultural, and other development and the Peace, Athabasca, and Slave River basins. Reviews the characteristics of the northern river basins and their peoples, the organisation of the Study, and major findings in the areas of environmental overview, use of aquatic resources, traditional knowledge, flow regulation, fish distribution and habitat, nutrients, dissolved oxygen, contaminants, drinking water, ecosystem health, modelling, human health, and cumulative effects. Recommendations by the Study Board, First Nations, and scientific advisors regarding such issues as basin management, monitoring, research, public participation, and a successor organisation are then presented. Also includes a summary of opinions, suggestions, and recommendations expressed at 17 community workshops held throughout the northern river basins area.

Presents results of contaminant analyses of bottom sediments collected from the Peace and Athabasca river basins 1988-90 and 1992. Contaminant groups represented are the polychlorinated dibenzo-p-dioxins and dibenzofurans, resin acids, chlorophenolic compounds, and polycyclic aromatic hydrocarbons. Contaminant concentrations were correlated with percent organic carbon of the fine fraction (the fraction on which analysis was performed. Correlations between concentrations of bleached kraft mill related contaminants were also investigated and results are presented.

Examines the mechanisms of natural riverine sediment production in the Northern River Basins Study area, together with the routine data for suspended sediment in the area's rivers, as background for the examination of sediment-associated contaminants. Topics examined include: the causative mechanisms and boundary conditions affecting the sediment regime, including area topography, geology, and hydrology; availability and adequacy of data on suspended sediments in the area; time trends of fluvial suspended sediment dynamics on a seasonal (open water and ice regime) and annual basis, over the long term, and in critical events; sediment sources, pathways, and fates, and sediment dynamics at basin-wide, reach, and site levels; sediment quality, including sediment-associated characteristics of pulp mill effluents and sediment-contaminant relationships; and implications for sediment-associated contaminants. Recommendations are made for monitoring and assessment of the sediment component of the area's ecosystem.