Temporal and Spatial Relationships of Suspended Sediments in Bioretention Cells (BRCs).

Urbanization incorporates impervious surfaces (roads, buildings, parking lots) into the landscape that degrade surface water quality compared to runoff originating from undeveloped areas. Bioretention Cells (BRCs) are a stormwater practice designed to infiltrate, store, and treat the first (most polluted) flush of stormwater. Pollutants are removed by plant uptake, microbes, adsorption, and filtered by the media before entering surface waters. These cells help to mitigate stormwater flow volume, flow rate, and remove nutrients. Suspended sediments commonly found in stormwater runoff decrease bioretention cell infiltration rates over time, rendering the practice less effective. Research on the effects of suspended sediments on infiltration rates has only been conducted in 1-D columns. BRCs interact with water flow and sediment multi-dimensionally, thus 3-D studies are crucial for understanding the dynamics of water flow and sediment load. By building a 3-D flow cell with suspended sediments pumped in at one outflow location, spatial variability of clogging within the filtration media can be further analyzed. This research can further assess whether the entire flow cell continues to participate in filtration after clogging occurs, or if the filter capacity is reduced in specific areas due to suspended sediment build up. Results can be used to simulate fate and transport of stormwater pollutants in BRCs.