11-26-2001 Council Packet - Laserfiche WebLink

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OCT-31-Ol MED 12:11 PH DEEPHAVEN CITY HALL FAX NO. 16124741274 P. 09 Section 330:00 operation. The amount of filter aid shall be selected to provide at least the same protection to the filler septum as would be provided by the use of 0.1 lbs. of filter aid per square foot of filter area per 24 hours. Use of additional equipment to provide body feed to tlic filter influent is optional. Where provided, such equipment shall have the capacity to continuously and uniformly feed at a rate of not less than 0.1 lbs. of filter aid per square foot of filler area per 24 hours. The filter piping shall be designed that during the prccoaiing operation, the effluent from the filter shall be recirculated or run to waste and shall not be fed into the pool until free of filter aid. An exception to this icquircmcnt may be made if Uic filter septum is of such construction that no perceptible quantity of filter aid is introduced into tire pool when tlic cfTlucnt discharges therein. Cartridge Type Filters. Cartridge type fillers are those where the cartridge itself Is the filter aid. Cartridge filters may be either pressure or vacuum type and are subject to the same general piping and lanlt sjrecifications as diatomile-type filters. Replacement cartridges arc divided into two types: depth and area. General specifications, however, arc the same for both. Cartridge fillers shall not require the addition of any flocculating agents such as ammonium alum, aluminum sulfate or potassium alum. They shall be subject to the same requirements listed under subsecUon (a) of this section for all types of filters. All types of cartridges shall have sufficient structural strength to resist rupturing, channeling, collapsing, or bursting at a maximum pressure differential of 50 psi. Cartridge shells shall be so designed as to prevent any by-passing of unfiltcred water. If provision is made for back-washing, it shall be so arranged as to not permit any backwash water to enter the recirculating system. No residue shall be permitted to remain in the filter-housing that could be picked up in the next filtering cycle. Cartridge elements shall be of either of the following types: 1.Depth t>pc cartridges, where the porosity varies from tlie inlet to the discharge surface. They shall have suflicient depth to provide adequate dirt-holding capacity and be designed for a flow of no more titan one gallon per minute per five cubic inches of volume with a pressure drop not to exceed two psi across clean cartridges and not to pass any particular matter larger than 25 microns. Area or surface type cartridges, which rely on the surface area for their dirt-holding capacity and follow the same flow per square foot of area as diatomitc filters, namely: three gallons per minute per square fool of filler area for vacuum filters. Addltionul fS^ndarda for Cartridge Type Fillers. ..