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W. O.W.T.S. OPERATIONAL DESIGN PARAMETERS AND COMPONENTS A. PROPOSED O.W.T.S. OPERATION SSS§3.7. Currently, all onsite domestic wastewater influent sources flow into individual septic tanks and then disposed of through adjacent leachfields. It is now proposed to centralize all but three of these septic tank effluent sources and pump it to the future disposal area. Buildings G, G2 and S will be standalone systems with existing septic tanks and adjacent leachfields which are to remain. The centralized septic tank effluent will be pumped partially-full (non-pressurized)through a 4" pipeline designed by others,as illustrated on the attached Plans. The disposal area design criteria, based upon the findings of these Studies, begin with this pipelined effluent flowing south into a 4,000 gallon, two compartment Jensen Precast, Inc. septic tank. Although the existing septic tanks are primary treatment, this 4,000 gallon tank will provide additional treatment to lower nitrogen, BOD and TSS concentrations by retaining particulate matter and promoting anaerobic digestion. Sizing for the 4,000 calculated tank capacity(CTC) is based on SJC EHD Form 42-01-004: 1,125 gal tank+(4,440 gpd ADF x 0.75) = 4,455 gals. Use 4,000 gal septic tank capacity. In addition to the treatment that will occur in this tank, a Polylok® PL-625 Effluent Filter is to be installed at the outlet. This filter provides 1/32" filtration, flow volumes up to 8,000 gpd and prevents particulate matter from entering the pump chamber tank. The filter should be inspected and cleaned once per year. The pump chamber septic tank is to be mono construction,two compartment, 1,500 gallon P&L Concrete, Inc. tank that is traffic rated(H-20 Loading). Both septic tanks are to be traffic rated since farm machinery will be operating in this location. The second compartment will contain the Orenco Universal Biotube Pump Vault. A duplex pump system is to be installed in the Biotube Vault, P/N Orenco PF3005 High Head Effluent Pump, 30 GPM, '/2 HP, 200V (2 pumps). The housing of both pumps will have additional screening of 1/16". All spec sheets for the OWTS components are found in Appendix G. The effluent will be pumped to the future filter bed, as described below. B. FILTER BED SIZING CALCULATIONS After the effluent is pressurized in the pump chamber tank, it travels west to the filter bed. The filter bed must be constructed under the setback requirements promulgated in Section 1.5 of the OWTS Standards. The vertical ht of the basin is 25 ft; therefore,the west edge of the filter bed must be: 25 ft x 4 = 100 ft from the top east edge of the stormwater basin. i Page -9- Chesney Consulting