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The soil in the borings was similar to that described by the Soil Survey. At locations P1, <br /> P2, and P3, clay was encountered to approximately four feet deep, followed by silty <br /> sand to the full depth of the holes. At location P4, sandy clay was encountered to <br /> approximately 4.5 feet deep, followed by silty sand to 12 feet deep, followed by medium <br /> to coarse sand with silt to the full depth of the hole. The soil logs are presented on <br /> Plates 12 and 13. <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 and moderate potential in the deeper soil zone. <br /> Sandy 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 /> Shallow and deep percolation testing 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 /> The percolation test holes were presaturated 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, both holes were found <br /> to be intact and dry. <br /> Percolation Test Procedure <br /> Live Oak conducted the percolation testing for the borings on November 16 through <br /> November 24, 2020. Standard four-hour tests were selected. Water level <br /> measurements were taken every 30 minutes during the four-hour period. The last 30 <br /> minutes of the test were observed by Daria Afonskaia or Aaron Gooderham, Registered <br /> Environmental Health Specialists at the San Joaquin County Environmental Health <br /> Department. <br /> LOGE 20-54 Page 5 <br />