1981-04-14 Septic System Design Report

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Mr. John Laurent - 3 - April 14, 1981 supply line should slope back towards the pumping chamber so that it drains after the mound is dosed. The laterals are 1.5 inch inside diameter pipes. The laterals should have 1/4 inch diameter holes drilled at a spacing of 3.0 feet. The laterals should be assembled to the manifold so that the holes point downwards into the rock bed. The distal ends of the laterals should be capped. Also, the last hole in each lateral should be drilled horizontally in the end cap near the crown of the pipe to facilitate air venting. A submersible effluent pump capable of del+vering at least 45 gallons per minute against a total dynamic head of at least "x" feet (as calculated below) should be used. 1. Vertical headloss a. Lot 1 - vertical headloss of approximately 7.8 feet between pump discharge (approx. elev. 93.6) and manifold (approx, elev. 101.4) b. Lot 2 - vertical headloss of approximately 10.5 feet between pump discharge (approx. elev. 91.0) and manifold (approx. elev. 102.5) 2. Friction headloss of 2.36 feet per 100 feet of 2 inch inside diameter PVC supply pipe a. Lot 1 - friction loss of 0.7 feet for 30 feet of pipe b. Lot 2 - friction loss of 2.1 feet for 90 feet of supply pipe 3. Five (5.0) feet to account for losses in distribution system Therefore for Lot 1 and Lot 2 the total dynamic heads are at least 13.5 feet and 17.6 feet, respectively. If any changes in system configuration are made, head - losses should be recalculated. The pump should be rigged with mercury float switches to dose about 150 gallons of effluent to the mound. All electrical connections should be watertight. Also an additional mercury float switch should be installed on a separate circuit to an alarm device to warn of pump failure. The floats should be rigged to allow 600 gallons reserve capacity in the tank. The sole purpose of soils data contained herein is evaluation of soil suit- ability for on -site absorption of septic tank effluent at the test site. Although soil texture and horizonation information and ground water elevation data may be helpful for the setting of basement elevations at this site, we cannot warrant any such interpretations or use of this data for other purposes.