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Soil Profile and Geologic Information <br /> The Site is depicted on the Geologic map of the San Francisco-San Jose quadrangle, <br /> California (Wagner, et al., 1991) within a map unit of the Laguna formation, described <br /> as consolidated alluvium (Plate 9). <br /> The surface and near surface soils located at the Site are reported by the USDA Web <br /> Soil Survey to be composed of Jahant loam (Plate 10) (USDA, 2020). The table below <br /> presents some selected properties of this soil: <br /> Table 1. Selected Properties of On-Site Soils (USDA, 1992) <br /> Soil Name Depth Unified Soil Salinity Soil Perme- Septic tank <br /> and Map Reaction ability absorption <br /> Symbol (in) Classification mmhos/cm pH (in/hr) fields <br /> Jahant 0-5 Loam; ML <2 6.1-7.3 0.6-2.0 Severe: <br /> loam, 5-31 Loam, clay loam; CL- <2 6.1-7.3 0.6-2.0 peres slowly <br /> 2-8% ML, CL <br /> slopes, 183 31-49 Clay, clay loam; CH, CL <2 6.1-7.3 < 0.06 <br /> 49-53 Cemented --- --- --- <br /> 53-60 Indurated --- --- --- <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 August 3, 2020, Live Oak excavated shallow and deep soil borings near the <br /> proposed septic disposal area of the Site for the purpose of percolation testing. The <br /> borings were four inches in diameter, 3.42 and 6.16 feet deep, and were excavated by <br /> hand auger. <br /> The location of the borings is indicated on Plate 11. <br /> The soil in the borings was similar to that described by the Soil Survey. Silty clay with <br /> sand was encountered to 2.5 feet deep, followed by sandy clay to the full depth of the <br /> holes. The soil log is presented 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 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 /> LOGE 20-31 Page 5 <br />