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The soil in the borings was similar to that described by the Soil Survey. Clay was <br /> encountered to approximately 6.5 feet below ground surface, followed by silt with very <br /> fine sand and clay to 8 feet, followed by fine sand with silt to the full depth of the hole. <br /> The soil log is presented on Plate 11. <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 better potential in the deep soil zone. Sandy <br /> soils generally have a much greater potential for percolation than fine-grained or <br /> 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 in 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 /> Live Oak presaturated the percolation test holes approximately 24 hours prior to the <br /> percolation testing. Each hole was filled with water to a height of 12 inches above the <br /> bottom of the boring for the presaturation. On the day of testing, the holes were found <br /> to be intact and dry. <br /> Percolation Test Procedure <br /> Live Oak conducted the percolation test for the borings on September 10, 2020. Due to <br /> the soil type present, a four-hour test was selected. Water level measurements were <br /> taken every 30 minutes during the four-hour period. The last 30 minutes of the test <br /> were observed by Naseem Ahmed, Registered Environmental Health Specialist at the <br /> San Joaquin County Environmental Health Department. <br /> LOGE 20-40 Page 6 <br />