Description
The effluent of the Cold Lake/Grand Centre regional sewage lagoon appears to have a minor impact on the quality of the Beaver River. The concentrations of nutrient parameters increased slightly in the river downstream of the effluent discharge. Total phosphorus increased from 0.080 mg/L at Beaver crossing to 0.090 mg/L at the border and then steadily declined to 0.040 mg/L at Highway 26 in Saskatchewan. Dissolved phosphorus increased from 0.032 mg/L at Beaver Crossing to 0.051 mg/L at the border and then declined to 0.008 mg/L at Highway 26. Conductivity also increased downstream of the discharge, however, the low conductivity of the effluent itself did not suggest a cause and effect relationship. The numbers of total and fecal coliforms did not increase downstream of the effluent and did not appear to be influenced by the lagoon discharge. These small changes occurred under extremely low flow conditions in the Beaver River. During flows more typical of November, the available...