Bioretention cells are an emerging low impact development technology that address urban stormwater runoff concerns. Field and column experiments were conducted to assess the efficacy of bioretention cells in cold conditions. Field experiments in a prairie environment demonstrated a significant decrease (91.5%) in effluent volumes compared to influent volumes. The majority (∼60%) of the runoff percolated to the surrounding soils or evapotranspirated. Cold condition performance significantly impacted high volume events and was characterized by significantly higher effluent volumes, significantly lower runoff storage, higher effluent peak flow rates, and longer peak delays. A partially frozen surface layer caused the changes in performance. Long-term simulation experiments on the columns indicated a significant decrease in saturated hydraulic conductivity over the first 4 equivalent years of operation, before levelling to a constant value.

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.