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Soil Profile and Geologic Information <br /> The Site is mapped on the Preliminary geologic map of Cenozoic deposits of the Bellota <br /> quadrangle, California (Marchand, D.E., and Bartow, J.A., 1979). It is depicted within a <br /> map unit of Holocene alluvium, composed of channel and levee deposits (Plate 7). <br /> The surface and near surface soils located at the Site are reported by the Web Soil <br /> Survey (USDA, 2018) to be composed of Columbia fine sandy loam (Plate 8). 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 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 /> Columbia, 0-12: Fine sandy loam; SM, <2 6.1 -7.8 2.0 -6.0 Moderate: <br /> fine sandy SC-SM flooding, <br /> loam, 12-60: Stratified sand to silt <2 6.1 - 7.8 2.0 -6.0 peres <br /> drained, loam; SM slowly. <br /> 0-2% <br /> slopes, 130 <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 November 13, 2018, Live Oak excavated shallow soil borings on both proposed <br /> parcels of the Site for the purpose of conducting percolation tests. The borings were <br /> four inches in diameter, 3.16 and 3.37 feet deep, and were excavated by hand auger <br /> (Table 2). The locations of the borings are indicated on Plate 9. <br /> The soil in the borings was more clayey than that described by the Soil Survey. In both <br /> borings, silty clay was encountered to the full depth of the hole. The soil log is <br /> presented on Plate 10. <br /> Discussion of Soil Lithology <br /> Based on the soil observed in the borings, there appears to be limited 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 1816 Page 5 <br />