The AquaShield™ Bio-Filter™ Stormwater Biofiltration System is a “tree box” design that provides an innovative and sustainable green infrastructure solution to meet the growing challenges of Low Impact Development (LID) practices. The Bio-Filter™ is a water quality treatment device capable of removing coarse and fine sediment, trash and debris, heavy metals bound to particulate matter, as well as oil by utilizing elements of pretreatment and biofiltration. The modular unit incorporates a trash shelf at the point or entry, a pretreatment chamber for removing coarse sediment, a biofiltration chamber using engineered soil, an internal bypass for high flow conditions, and an outlet chamber prior to discharge.
Each Bio-Filter™ unit is constructed of lightweight and durable Polymer Coated Steel (PCS) to provide long term operational and structural functionality. Available model sizes range from 4 x 4 feet to 6 x 8 feet in area (16 to 48 square feet). The engineered biomedia can be utilized with 18 or 24 inches of depth. Each unit also includes two 15-inch diameter access ports to the trash shelf, pretreatment chamber and underdrain area to facilitate inspection and maintenance activities. A decorative metal tree grate is included for each unit. A non-skid surface material is used for the top of each unit, and on request, can also be applied to the sides of the unit. Structural integrity of each unit is leak tested at the factory prior to shipping. No heavy lifting equipment is needed for installation. Each unit is shipped with the biomedia pre-installed. It is the responsibility of the contractor to install the vegetation that is specified by others.
Independent testing of the Bio-Filter™ media demonstrates a high level of performance. The biomedia achieves over 90% removal of fine-grained sediment based on performance testing using the manufactured test sediment SIL-CO-SIL 106 (median particle size of 22 microns). The biomedia also attains up to 96% removal of insoluble (total) forms of copper and zinc. These effective levels of sediment and metals removal are achieved at gravity flow infiltration rates up to 135 inches per hour. Phosphorus removal is enhanced by both plant and biomedia uptake. The pretreatment chamber is based on the principle of hydrodynamic vortex separation. The internal bypass design not only allows for the elimination of an external bypass structure, but also provides for an overall reduced installation footprint and associated piping connections.