Potential eutrophication of the Rideau River by an urban drainage waterway.
|Title:||Potential eutrophication of the Rideau River by an urban drainage waterway.|
|Authors:||Habicht, Martin Hans.|
|Abstract:||Urban drainage within the City of Ottawa, Ontario, is thought to be a significant contributor of nutrients to the already eutrophic Rideau River. Both chemical characterization and algal bioassay were used to study the nutrient effects of Saw Mill Creek, a major urban drainage waterway to the Rideau River. Saw Mill Creek was sampled during peak storm flow, when both high concentrations of nutrients and high flow conditions prevailed. Peak flows averaged 9 percent of the flow in the Rideau during the study period. Although nutrient concentrations were shown to be greater during storm flows, peak flow concentrations for total phosphorus and nitrogen averaged only 0.190 mg-P/l and 2.5 mg-N/l. These concentrations of nutrients did not significantly stimulate algal growth at the 5 percent addition level. However, at the 10 and 20 percent addition level, bioassays produced on the average 0.96 and 1.96 mg/l of algal standing biomass, respectively. These values were significantly different (P<0.05) from the average biomass of 0.50 mg/l produced by the Rideau samples. Alum treatment of Saw Mill Creek, simulated by the jar test, was generally unable to reduce algal growth when compared at any of the addition levels. The treated 5 percent addition produced virtually the same average algal biomass as the untreated, and thus it was concluded that treatment would have no effect on algal growth at low flows of Saw Mill Creek. It was recommended that a non-structural solution for the reduction of storm flows in Saw Mill Creek be sought, so that the associated decrease of nutrient concentrations would reduce the algal growth potential.|
|Collection||Thèses, 1910 - 2010 // Theses, 1910 - 2010|