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The surface and near surface soils located at the Site are reported by the USDA Web <br />Soil Survey to be composed of Stomar clay loam (Plate 10) (USDA, 2022). The table <br />below presents some selected properties of this soil: <br />Table 1. Selected Properties of On -Site Soils (USDA, 1992) <br />Soil Name <br />Depth <br />Unified Soil <br />Salinity <br />Soil <br />Perme- <br />Septic tank <br />and Map <br />(in) <br />Classification <br />mmhos/cm <br />Reaction <br />ability <br />absorption <br />Symbol <br />pH <br />(in/hr) <br />fields <br />Stomar clay <br />0-17 <br />Clay loam; CL <br /><2 <br />6.6-7.3 <br />0.2-0.6 <br />Severe: <br />loam, 0-2% <br />17-47 <br />Clay loam, clay; CL, CH <br /><2 <br />6.6-8.4 <br />0.06-0.2 <br />peres slowly <br />slopes, 252 <br />47-60 <br />Clay loam, silty clay <br /><2 <br />7.4-8.4 <br />0.2-0.6 <br />loam; CL <br />Note: The table descriptions do not necessarily reflect site-specific soil properties. See description of the map unit for <br />composition and behavior characteristics of the map unit. <br />Soil Borings <br />On February 22, 2022, Live Oak excavated a shallow soil boring roughly equidistant <br />between the proposed septic disposal area of the ADU and the proposed expansion <br />area of the existing house for the purpose of percolation testing. The boring was four <br />inches in diameter, 2.86 feet deep, and was excavated by hand auger. The location of <br />the boring is indicated on Plate 11. <br />The soil in the boring was similar to that described by the Soil Survey. Silty clay was <br />encountered to the full depth of the hole. The soil log is presented on Plate 12. <br />Discussion of Soil Lithology <br />Based on the soil observed in the boring, there appears to be moderate potential for <br />percolation in the shallow soil zone. Sandy soils generally have a much greater <br />potential for percolation than fine-grained or cemented soils. However, a percolation <br />test is the only accepted method for determining the suitability of the soils for a septic <br />disposal area. Percolation test results are discussed in the following section. <br />Percolation Test <br />A shallow percolation test was conducted near the proposed septic disposal areas of <br />the Site. The soil boring discussed above was used for the percolation test hole. <br />Percolation test procedures conformed to San Joaquin County Environmental Health <br />Department policy. <br />Preparation and Presaturation of Percolation Test Holes <br />After the boring was advanced by hand auger and the soil logged, the test hole was <br />completed for the percolation testing. Approximately two inches of pea gravel were <br />LOGE 2213 Page 5 <br />