The limnology of two proximal pit lakes after twenty years of intense flooding

Two adjacent pit-lakes, Caland and Hogarth, formed after the flooding of open pit iron mines near Atikokan, Ontario, Canada, were examined for their water quality relationships and potential to support aquaculture. Detailed sampling for physical and chemical parameters took place during 1998, 1999, and early 2000.;Since mining terminated in 1979, both pits have continued to fill with water from rainfall, snowmelt, and groundwater seepage, and, by 2000, had water depths in excess of 160 m. Water quality in both pit-lakes was largely dependent on proximal waste rock composition and surficial geology of the area. Drainage was a major factor in distinguishing the water quality between the two pit-lakes. Statistically significant variations occurred between the two pit lakes for metal, anion, cation, conductivity, hardness, and dissolved oxygen concentrations. Variations in precipitation and evaporation between the two sampling years resulted in increased or decreased ion concentrations for the same seasons or depths within the two pit-lakes. (Abstract shortened by UMI.)...