The characterization and distribution of inorganic chemicals in tributary waters of the lower Athabasca river, Oilsands region, Canada.

At present, there are two large industrial plants recovering oil from the lower Athabasca oil sands area and there are plans for several more mines in the area. There are environmental concerns for aquatic life in areas downstream of current and future oil sands activities. To assess and predict potential impacts of industrial activities, it is important to separate impacts from those produced by naturally occurring oil sands deposit. Studies were therefore conducted to determine whether the water quality of tributaries to the Athabasca River, which have not been impacted by anthropogenic activities, is affected by inorganic constituents resulting from flowing through reaches with natural oilsands deposit. Three tributaries, Steepbank River, Mackay River, and Ells River at upstream and downstream locations on each stream were investigated during four surveys from 1998 to 2000. In addition to some physical parameters such as pH, conductance and hardness and the major ions (calcium, magnesium, sodium, potassium, bicarbonate, chloride, sulfate, and silicates), seventeen trace metals were investigated. Some of these metals, especially iron and manganese, were of high concentrations and in some instances, particularly in a survey conducted during the spring freshets in April 1999, exceeded guidelines for the protection of aquatic life. The observed concentrations of metals seem to be of natural origin and can be used as base-line data for future assessment of anthropogenic activities in the oil sand region.