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LATERAL LENGTH AND DIAMETER Piping to consist of PVC Schedule 40. Lateral length is to be 180 ft for each lateral, including the clean-out sweep assembly. The diameter shall be 2" ID. PERFORATION SIZE, SPACING AND NUMBER PER LATERAL Orifices shall be preferably 1/8 in. dia. For effluent distribution applications to be -5 f 2 /orifice, the spacing of orifices = 5 feet. The number of orifices per lateral shall be: N = (p x) + 0.5 = (180 ft ÷ 5 ft) + 0.5 = 36.5 perforations per lateral x 2 laterals = 73 total perforations By having orifices in the 12 o'clock position and check valves at the discharge line, the pumps will not have to charge the piping network at the time of every dose. LATERAL DISCHARGE RATE (LDR) Required distal pressure is 5 ft, translates to 0.43 gpm per orifice. LDR = 0.43 gpm/perforation x 36.5 orifices perforations/lateral = 15.7 gpm/lateral. FORCE MAIN AND LATERAL DIAMETER The force main is to be 2.0 in. I.D., and the laterals are to be 2.0" I.D. TOTAL DYNAMIC HEAD (TDH) The TDH the pump must work against: System network head = 1.3 (cony, factor) x distal pressure 5 ft = 6.5 ft Elevation distance between the pump and the highest elevation of the distribution network -,5.0 ft Friction loss in discharge ,-0.5 ft + loss thru laterals 0.3 ft = TDH: 6.5 + 5 + 0.8 z 12.9 ft PUMP REQUIREMENTS The pumping system for effluent disposal will consist of a duplex pump arrangement, with the pumps alternating back and forth. A duplex pump system (Orenco P/N PF300511x2), each pump pumping 16 gpm against 13 feet of head. The Alternating Control Panel is Orenco P/N MVP-DAX1DM. DOSE VOLUME Use 10 times the lateral void volume, or 25% of the ADF (ADF = 600 gpd x 0.25 = 150 gpd): Lateral dia. = 2.0 in., Lateral length = 180 ft, Number of laterals = 1 of 2, Lateral void volume = 0.082 gal/ft Net Dose Volume = 10 x 180 x 1 x 0.082 = 148 gals/dose. Floats shall be set to dose an approximate volume of 150 gals/dose. Pump delivers 30 gpm; therefore, set timer for 5 minutes. Pumps alternate every 6 hrs, 4x/day. Orenco MF1P consisting of four Signal Floats shall be used to time dose the effluent. The bottom float, or lowest float, is to be the Redundant Off (RO) float. The second float is the On/Off Timer. The third float is the On/Off Override Timer and the fourth float is the High Level Alarm (HLA) and Lag Pump Enabled. When the first float is in the off position, this protects the pumps from operating if insufficient effluent has been generated. The timer enable and the RO functions are controlled by the same float. 11 Chesney Consulting