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Soil Profile and Geologic Information <br /> The Site is depicted on the Preliminary geologic map showing Quaternary deposits of <br /> the Lodi quadrangle, California (Marchand and Atwater, 1979). The Site is depicted <br /> within map units of the Modesto formation upper member, described as "arkosic <br /> alluvium forming Mokelumne River alluvial fan; chiefly sand, becoming finer-grained <br /> toward fan toe; probably glacial outwash" and "arkosic sand forming low dunes on the <br /> Mokelumne River fan and in the Delta" (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 Tokay fine sandy loam and Tujunga loamy sand (Plate <br /> 10) (USDA, 2021). The table below presents some selected properties of these soils <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 (in) Class <br /> Reaction ability absorption <br /> Symbol Classification mmhos/cm pH (in/hr) fields <br /> Tokay fine 0-19 Fine sandy loam; SM <2 6.1-7.8 2.0-6.0 Slight <br /> sandy loam, 19-45 Fine sandy loam, sandy <2 6.1-7.8 2.0-6.0 <br /> 0-2% loam, SM <br /> slopes, 45-60 Fine sandy loam, sandy <2 6.1-8.4 2.0-6.0 <br /> 256 loam, coarse sandy <br /> loam; SM <br /> Tujunga 0-22 Loamy sand; SW-SM, <2 6.1-7.3 6.0-20 Severe: <br /> loamy sand, SM, SP-SM poor filter <br /> 0-2% 22-67 Loamy sand, fine sand, <2 6.1-7.8 6.0-20 <br /> slopes, sand; SW-SM, SM, SP- <br /> 259 SM <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 March 4, 2021, Live Oak excavated shallow and deep soil borings near the <br /> proposed septic disposal area of the Site for the purpose of conducting a percolation <br /> test. The borings were four inches in diameter, 3.04 and 7.59 feet deep, and were <br /> excavated by hand auger (Table 2). <br /> The locations of the borings are indicated on Plate 11. <br /> The soil in the borings was similar to that described by the Soil Survey. Silty sand was <br /> encountered to approximately 2.5 feet below ground surface, followed by sandy silt to <br /> approximately 5 feet, followed by silty clay to approximately 5.5 feet, followed by sandy <br /> silt to approximately 6 feet, followed by silty sand to the full depth of the hole. The soil <br /> log is presented on Plate 12. <br /> LOGE 2107 Page 5 <br />