Experimental Study on Particle Clogging of Biofilter Device in Urban Areas

Biofilter devices are becoming increasing popular stormwater management controls in urban areas to reduce runoff volume, peak flows and stormwater pollutants impact on receiving waters. However the performance of these systems is affected by clogging, either at the surface, on buried geotextiles, or at an underdrain outlet. This paper presents a study conducted to evaluate the clogging potential of a newly developed foundation drain material (SmartDrain™) that can be used in biofiltration devices and provides another option for outlet control. Clogging potential of SmartDrain™ material was tested after excessive loadings by fine ground silica particulates and biofouling experiments. The results indicated that both tests had only a small effect on the discharge rates and the Reynolds number ranged between 100 to1000. A comparison of biofilter underdrain options and water balance using WinSLAMM (Source Loading and Management Model for Windows) indicated that SmartDrain™ reduces ponding time, while providing additional infiltration and increased media contact time.