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reasonably be required to remove this contaminant should it occur in drinking water. <br />The Maximum Contaminant Level Goal (MCLG) for DBCP is zero. <br />Soil Profile and Geologic Information <br />The Site is depicted on the Preliminary geologic map of Cenozoic deposits of the <br />Bellota quadrangle, California (Marchand and Bartow, 1979). The Site is depicted <br />within a map unit of the Riverbank formation upper member described as "arkosic <br />alluvium forming Mokelumne River terraces and alluvial fan; chiefly sand; probably <br />glacial outwash" (Plate 8). <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, thick surface (Plate 9) (USDA, 2022). <br />The table below presents some selected properties of this soil. <br />Table 1. Selected Properties of On -Site Soils (USDA, 1992) <br />Soil Name <br />Unified Soil <br />Salinity <br />Soil <br />Perme- <br />Septic tank <br />and Map <br />Depth (in) <br />Classification <br />mmhos/cm <br />Reaction <br />ability <br />absorption <br />Symbol <br />pH <br />(in/hr) <br />fields <br />San Joaquin <br />0-12: <br />Loam; CL -ML, ML <br /><2 <br />5.6-6.5 <br />0.6-2.0 <br />Severe: <br />loam, thick <br />12-26: <br />Sandy clay loam; SC <br /><2 <br />6.1-7.3 <br />0.2-0.6 <br />cemented <br />surface, 0- <br />26-35: <br />Clay loam, clay; CL <br /><2 <br />6.1-7.8 <br /><0.06 <br />pan, peres <br />2% slopes <br />35-60: <br />Indurated <br />--- <br />--- <br />--- <br />slowly <br />240. <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 2, 2022, 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, 2.14 feet deep, and was excavated by hand auger. The <br />location of the boring is indicated on Plate 10. <br />The soil in the boring was similar to, though sandier than, that described by the Soil <br />Survey. Sandy silt with clay was encountered to 1.7 feet below ground surface (bgs), <br />followed by silty sand to the full depth of the hole. The soil log is presented on Plate 11. <br />Discussion of Soil Lithology <br />Based on the soil observed in the boring, there appears to be some 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 2203 Page 5 <br />