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Soil Borings <br /> On or about July 15, 2020, Live Oak excavated a shallow soil boring by hand auger <br /> near the proposed septic disposal area of the Site for the purpose of conducting a <br /> percolation test. Based on preliminary percolation test results in the shallow soil boring, <br /> Central Valley Septic Services was retained to excavate a deep boring as well; this <br /> boring was drilled on August 13, 2020 with a Spiradrill AHD 50. The shallow boring was <br /> four inches in diameter and 3.40 feet deep, while the deep boring was 12 inches in <br /> diameter and 22.73 feet deep (Table 2). The location of the borings is indicated on <br /> Plate 11. <br /> The soil in the borings was similar to that described by the Soil Survey. Sandy silt was <br /> encountered to 4 feet below ground surface (bgs), followed by a hardpan of sandy silt to <br /> 7 feet bgs, sandy clay to 9 feet bgs, silty sand to 14 feet bgs, silty sand with clay to 16 <br /> feet bgs, silty medium sand to 18 feet bgs, sandy clay to 20 feet bgs, cemented silty <br /> sand to 22 feet bgs, and fine sand to the full depth of the hole. The soil log is presented <br /> on Plate 12. <br /> Discussion of Soil Lithology <br /> Based on the soil observed in the borings, there appears to be limited potential for <br /> percolation in the shallow soil zone, but good potential for percolation in the 22-foot soil <br /> zone. Sandy soils generally have a much greater potential for percolation than fine- <br /> grained or cemented soils. However, a percolation test is the only accepted method for <br /> determining the suitability of the soils for a septic disposal area. Percolation test results <br /> are discussed in the following section. <br /> Percolation Test <br /> A shallow and deep percolation test was conducted near the proposed septic disposal <br /> area of the Site. The soil borings discussed above were used for the percolation test <br /> holes. Percolation test procedures conformed to San Joaquin County Environmental <br /> Health Department policy. <br /> Preparation and Presaturation of Percolation Test Holes <br /> After the borings were advanced by hand auger and the soil logged, the test holes were <br /> completed for the percolation testing. Approximately two inches of pea gravel were <br /> placed in the bottom of each open soil boring, followed by a 2.0-inch diameter PVC pipe <br /> with perforations on the bottom. Pea gravel was then used to backfill a few inches of <br /> the annular space. <br /> LOGE 20-27 Page 5 <br />