Operation - Bio-Filter™ Stormwater Biofiltration System

Operation begins when water enters the Bio-Filter™, commonly through a curb inlet, and flows onto the trash shelf. The water quality treatment flow next enters the pretreatment chamber where coarse sediment is captured by hydrodynamic vortex separation. The pretreated water then enters the biofiltration chamber and is evenly distributed across the top of the engineered biomedia. Water flows downward driven by gravity flow through the biomedia and plant root ball to remove fine sediment, heavy metals, residual oil and phosphorus. The treated water then enters an underdrain pipe placed within a basal gravity bed. Water is conveyed via the underdrain pipe to the adjacent outlet chamber positioned underneath the trash shelf. The Bio-Filter™ also includes an internal bypass mechanism designed not only to accommodate high flow conditions, but also to minimize the device’s installation footprint by eliminating the need for any external bypass structures. Internal bypass occurs when the head level rises within the unit such that flows in excess of the water quality treatment flow will spill across the overflow weir on the trash shelf and downward into the underlying outlet chamber.