9929 EVERGREEN WAY HORIZON BANK 2018-01-01 MF Import

is available and can be customized for each s!!e to target and remove the desired levels u( aediments, dissolved phosphorus, dissolved metals, organics, and oil and grease. In many �ases, a combination of media is recommende6 to maximize the effectiveness of the stormwater pollutant removai. Figure 1. The StormFilter Cartridge Priming System Function When stormwater in the StormFilter unit enters a StormFilter cartridge, it percolates horizontally thrcugh the cartridge's filter media and coilects in the center tube of the cartridge, where the float in the cartridge is in a closed (downward) position. Water continues to pass through the filter media and into the cartridge's center tube. The air in the cartridge is displaced by the water and purged from beneath the filter hood through the one-way check valve located in the cap. Once the center tube is filled with water (approximately 18 inches deep), there is enough buoyant force on the float to open the float valve and allow the treated water in the center tube to flow into lhe under-drain manifold. This causes the check valve to close, initiating a siphon that draws polluted water throughout the full surface area and volume of the filter. Thus, the entire fiiter cartridge is used to filter water throughout tlie duration of the storm, regardless of the water surFace elevation in the unit. This siphon continues until the water surface elevation drops to the elevation of the hood's scrubbing regulators. The cartridges are connected to the under- drain manifold with a plastic connector. Since some media used is potentially buoyant, a threaded connector affixed to the under-drain manifoid (with glue or other adhesive) is necessary to ensure that the cartridge isn't lifted out of place. For the heavier compost media, 2 slip connector is used. The StormFilter is also equipped with flow spreaders that trap floating debris and surface films, even during overflow conditions. Depending on individual site characteristics, some systems are equipped with high andlor base flow bypasses. High flow bypasses are installed when the calculated peak storm event generakes a flow that overcomes the over(low c:apacity of the system. This is especialiy important fcr precast systems. Base flow bypasses are sometimes installed to bypass continuous inflows caused by ground water seepage, which usually do not require treatmen!. All StormFilter units are designed with an overflow. The overFlow operates when the inflow rate is greater than the treatment capacity of the filter cartridges. Stormwater A1anagement, Inc. 002004 StormFilter Operation and Maintenance Guidelines 2 ot 9 33