Bioretention cell efficacy in cold climates: Part 2 — water quality performance

Abstract

Field and column experiments were conducted to test the ability of bioretention cells to improve urban runoff quality. The effects of cold climate conditions, media depth, long-term operation, and extreme loading were analyzed. Field experiments demonstrated significant decrease in contaminant mass, which was a function of the large runoff volume capture. Significant decreases in concentration for sediment (96%), biochemical oxygen demand (BOD, 8%), and total phosphorus (0.6%) were noted. Long-term simulation experiments demonstrated a decrease in effluent concentration over time, suggesting a dependence on media chemistry. Sediment and BOD capture remained high throughout the testing period. Media depth did not impact performance in laboratory experiments. Extreme loading experiments proved that the effluent concentration of contaminants was independent of the influent concentration. Cold climate conditions did not have a significant impact on performance in both field and column experiments.