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One(1) shallow percolation test was performed on the site which which had a percolation <br /> rate of 250 min/in (Neil O. Anderson, 2001). A percolation rate of 250 min/in was selected for <br /> the design rate which reflects a clayey type soil found on the site (see Table No. 1). This value <br /> was converted into units of inches per day (see Equation No. 3) <br /> Equation No. 3 <br /> 250 min/in = 0.002 in/min <br /> 0.002 in/min x 1440 min/day = 5.76 in/day <br /> Table 1. <br /> Summary of Shallow Percolation Test Conducted on the Site <br /> (Neil O. Anderson &Assoc., Inc. 2001) <br /> Percolation Test P-1 <br /> Depth(ft)of test. 2.0 <br /> Percolation rate(min/in). 250 <br /> Percolation rate(in/day). 5.76 <br /> The percolation rate of 5.76 in/day (250 min/in) was multiplied by a sewage factor of 0.1. <br /> The sewage factor ranges from 0.04 for unfiltered sewage to 0.1 for sand-filtered sewage. We <br /> applied a sewage factor of 0.1 to the percolation rate due to the of the use of a sand bed filter(see <br /> Equation No. 4). The percolation rate adjusted for the sewage factor is 0.576 in/day. <br /> Equation No. 4 <br /> 5.76 in/day x 0.1 = 0.576 in/day <br /> The available effluent loading rate was found by subtracting the adjusted percolation rate <br /> from the deficit rate from climatic graph(see Equation No. 5 ). The difference was converted <br /> into gallons per day per square foot (gpd/ ftl)(see Equation No. 6). The ETA effluent loading <br /> rate was found to be 0.436 gpd/ftz for the site based on a relatively high deficit rate taken on <br /> January 22 and a relatively low shallow percolation test rate of 250 min/in. The ETA sewage <br /> loading rate essentially reflects average winter conditions where average daily precipitation is <br /> slightly higher than average daily evapotranspiration. The surplus loading rate is gained through <br /> minor soil percolation when average precipitation slightly exceeds average ETo. The slight gain <br /> through percolation is the available loading rate during the winter period from soils underlying <br /> the filter bed. <br /> Equation No. 5 <br /> 0.576 in/day - 0.14 in/day = 0.436 in/day <br /> —Calculations,Page 2— <br />