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<br />LOGE 2126 Page 2 <br /> <br />PHYSICAL SETTING <br /> <br />Topography <br />The elevation of the Site, according to a United States Geological Survey topographic <br />map, is approximately 20 feet above mean sea level (Plate 3). The Site is relatively flat. <br />Geology <br />The Site is mapped on the Geologic Maps of the Sacramento-San Joaquin Delta, <br />California (Atwater, B.F., 1982). It is depicted within a map unit of the Modesto <br />formation described as “loose sand and silt, chiefly fluvial (Plate 4). <br />Soil Analysis <br />Chemical and Physical Properties of the Soil <br />The surface and near surface soils located at the Site are reported by the Web Soil <br />Survey (USDA, 2021) to be composed of Tinnin loamy coarse sand (Plate 5). The table <br />below presents some selected properties of this soil type: <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 />Tinnin loamy <br />coarse sand, <br />0-2% slopes, <br />255 <br />0-28: <br /> <br />28-53: <br /> <br />53-75: <br />Loamy coarse sand; <br />SM <br />Loamy coarse sand, <br />loamy sand; SM <br />Loamy coarse sand, <br />loamy sand, sand; SM <br /><2 <br /> <br /><2 <br /> <br /><2 <br /> <br />6.1-7.8 <br /> <br />6.1-7.8 <br /> <br />6.6-8.4 <br />6.0-20 <br /> <br />6.0-20 <br /> <br />6.0-20 <br />Severe: <br />poor filter <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 />The soil encountered on the Site was similar to that described by the Soil Survey. On <br />April 15, 2021, Live Oak excavated a soil boring to four feet below ground surface on <br />the Site for the purpose of soil profiling. The soil was found to be silty sand to the full <br />depth of the boring. <br />Mass Transport Soil Properties <br />This soil type usually allows relatively rapid infiltration of water through the surface soils. <br />However, a percolation test is the only sure indicator of Site-specific infiltration speed.