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Soil Profile and Geologic Information <br />The Site is depicted on the Preliminary Geologic Map of the Lodi 30' x 60' Quadrangle, <br />California (Dawson, 2009). The Site is depicted within map unit of the Riverbank <br />formation upper and middle units (Plate 11). The Riverbank formation is described as <br />"arkosic alluvium, sand ... and silt, forming terraces, and alluvial fans along the <br />Cosumnes and Mokelumne Rivers." <br />The surface and near surface soils located at the Site are reported by the USDA Web <br />Soil Survey to be composed of San Joaquin loam (Plate 12) (USDA, 2019). 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 />and Map <br />Symbol <br />Depth <br />(in) <br />Unified Soil <br />Classification <br />Salinity <br />mmhos/cm <br />Soil <br />Reaction <br />pH <br />Perme- <br />ability <br />(in/hr) <br />Septic tank <br />absorption <br />fields <br />San Joaquin <br />loam, 0-2% <br />slopes, <br />238 <br />0-16 <br />16-26 <br />26-60 <br />Loam; CL-ML, ML <br />Clay loam, clay; CL <br />Indurated <br /><2 <br /><2 <br />5.6-6.5 <br />6.1-7.8 <br />0.6-2.0 <br /><0.06 <br />Severe: <br />cemented <br />pan, percs <br />slowly <br />San Joaquin <br />loam, 2-8% <br />slopes, <br />eroded, <br />0-16 <br />16-26 <br />26-60 <br />Loam; CL-ML, ML <br />Clay loam, clay; CL <br />Indurated <br /><2 <br /><2 <br />5.6-6.5 <br />6.1-7.8 <br />0.6-2.0 <br /><0.06 <br />Severe: <br />cemented <br />pan, percs <br />slowly <br />239 <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 June 22, 2019, Live Oak excavated a shallow soil boring near the proposed septic <br />disposal area of the Site for the purpose of conducting a percolation test. The boring <br />was four inches in diameter, 3.45 feet deep, and was excavated by hand auger (Table <br />2). The location of the boring is indicated on Plate 13. <br />The soil in the boring was similar to, but sandier than, that described by the Soil Survey. <br />Silt was encountered to 1.5 feet below ground surface, followed by sandy clay to 2.3 <br />feet, followed by cemented silty sand to the full depth of the hole. The soil log is <br />presented on Plate 14. <br />Discussion of Soil Lithology <br />Based on the soil observed in the boring, there appears to be limited 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 />LOGE 1929 Page 4