Storm Water Best Management Practices into the Existing Urban Landscape — Systems for Controlling Sediments

The operation of an `advanced' hydrodynamic vortex separator (AVS) designed for stormwater sediment interception has been examined using particle capture and retention efficiency testing and dye tracer testing. For retention efficiency in particular (referring to the efficiency with which a chamber retains pollutants following capture) the results are compared with those for other configurations, including simple vortex and gravity separation devices. The results show how the collection and retention efficiencies of the AVS are enhanced through the presence of a quiescent zone in the base where solids are stored. A simple model of system operation is considered, based on the surface loading rate of the active region and the particle sedimentation velocity. It is concluded that a comprehensive model of system performance needs to take into account a variety of factors, including the detailed characteristics of the sediment material and the hydrodynamic characteristics of the specific separation device in question.