Stormwater Treatment 1604 San Leandro Boulevard 042122

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All PerkFilter systems include a high -flow bypass assembly to divert flow exceeding the treatment capacity of the filter cartridges around the treatment chamber. The bypass assembly routes peak flow from the inlet chamber directly to the outlet chamber, bypassing the treatment chamber to prevent sediment and other captured pollutants from being scoured and re -entrained by high flow. Treated flow and bypass flow merge in the outlet chamber for discharge by a single outlet pipe. Vent tube Outer media la Center tube assembly Inner media la Outer screen Connection to outlet chamber (with draindown) Figure 2. Schematic of PerkFilter cartridge. Configuration The PerkFilter structure may consist of a vault, manhole, or catch basin configuration. Catch basin units may be fabricated from concrete or steel. Internal components including the PerkFilter cartridges are manufactured from durable plastic and stainless steel components and hardware. All cartridges are 18 inches in diameter and are available in two heights: 12-inch and 18-inch. Cartridges may be used alone or may be stacked (Figure 3) to provide 24-inch and 30-inch combinations. The capacity of each cartridge or cartridge combination is dictated by the allowable operating rate of the media and the outer surface area of the cartridge. Thus, taller cartridges have greater treatment capacity than shorter cartridges, but they also require more hydraulic drop across the system. Cartridges may be filled with a wide variety of media but the standard mix is composed of zeolite, perlite and carbon (ZPC). Access to an installed PerkFilter system is typically provided by ductile iron castings or hatch covers. The location and number of access appurtenances is dependent on the size and configuration of the system. A clear copy can be viewed at: City of San Leandro, 835 East 14'h Street, City Hall, San Leandro, CA 94577