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(Qmjo) is described as "Qmt (arkosic alluvium forming Mokelumne River alluvial fan; <br /> chiefly sand; probably glacial outwash) and Qmtb (basin alluvium derived from the <br /> Mokelumne and Calaveras Rivers; includes arkosic alluvium, probably glacial outwash, <br /> and locally-derived materials; chiefly fine sand and silt) overlain by 0.5 to 2 m of Qm2 <br /> deposits" (Plate 9). <br /> The surface and near surface soils located at the Site are reported by the Web Soil <br /> Survey (USDA, 2019) to be composed of Devries sandy loam, drained (Plate 10). The <br /> table below presents some selected properties of this soil type: <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) Classification mmhos/cm Reaction ability absorption <br /> Symbol pH (in/hr) fields <br /> Devries 0-13 Sandy loam; SM <2 6.6-8.4 2.0-6.0 Severe: <br /> sandy loam, 13-28 Sandy loam, fine sandy <2 6.6-8.4 2.0-6.0 cemented <br /> drained, 0- loam; SM pan <br /> 2% slopes, 28-80 Indurated --- --- --- <br /> 149 <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 October 27, 2014, Neil O. Anderson & Associates (NOA) excavated two shallow soil <br /> borings on the Site for the purpose of conducting percolation tests. The borings were <br /> four inches in diameter, three feet deep, and were excavated by continuous flight auger <br /> (Table 2). The locations of the borings are indicated on Plate 11. Discussion of the soil <br /> borings and percolation testing is based on NOA's 2014 Geotechnical Investigation <br /> (Appendix 2). <br /> NOA found that the soils at the Site consist of silty sand. Live Oak inspected the soils <br /> on January 30, 2019 as part of the Nitrate Loading Study, and also found them to <br /> consist of silty sand. <br /> Discussion of Soil Lithology <br /> Based on the soil observed in the borings, there appears to be good potential for <br /> percolation at the test locations. Sandy soils generally have a much greater potential <br /> for percolation than fine-grained or cemented soils. However, a percolation test is the <br /> only accepted method for determining the suitability of the soils for a septic disposal <br /> area. Percolation test results are discussed in the following section. <br /> LOGE 20-02 Page 6 <br />