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Omega Vineyard,Phase I <br /> Page No. 2 <br /> It is proposed to-utilize shallow leach-lines withdrywells on the ends for on-site disposal <br /> of sewage effluent. The.number and length of leach lines and the number of dry wells:has been <br /> determined based on the design flow and the results of the percolation testing and calculations. " <br /> Following are the calculations supporting the proposed design. <br /> II. Design Calculations <br /> Shallow Leach Lines: <br /> Initial disposal of effluent will be in shallow leach lines. The four shallow percolation ' ' <br /> tests'performed throughout the site had rates of 62.-5,'8 3, 83 min/in., and no drop,in the.last 30 <br /> min. of test: The two tests performed in the area of the proposed leach lines had rates of 83 <br /> miii/in. and no drop.- Based_on the results of the shallow-tests,.a'design percolation rate of 100- <br /> min/in. <br /> 00 min/in. was selected. <br /> The purpose of the following calculations is to determine an effluent application rate,for. . <br /> shallow leach lines (expressed in units of gal/daylft. of leach line) for a given percolation rate. <br /> Figure 3 in the Manual of Septic Tank-Practice gives recommended square feet of absorption <br /> ' area required'per bedroom for percolation-rates vaiying from 0 to 60 min/in. By making-the <br /> 3: _ <br /> following.assumptions and calculation, percolation rates can be converted into-clear water rates <br /> with.units-of gal/day/ft2 of absorption area:' <br /> Assumptions: <br /> Percolation test hole diameter. A0 in. <br /> .Ave. depth of water in test hole., = 3 in. <br /> Calculations: <br /> To,conveii percolation rate with units of min/in to gal/day/ft' of absorption area, <br /> the following formula was used: <br /> A(6.23) <br /> R . F-quation-('I-1) <br /> rAs <br /> R . = Converted rate, gal/day/fti of-absorption area,.. <br /> r = test percolation rate,-min/in. <br /> A = Cross section area of test hole, int <br /> Average total sidewall and bottom area in contact with water, in?' <br /> By assuming,an effluent application rate of 100 gal/day/bedroom for the values in the <br /> ' Figure 3 chart, the following-Table.2 was-produced which gives various clear water application, <br /> rates and the back calculated sewage application factors for different percolation rates. li <br />