Laserfiche WebLink
Soil Profile and Geologic Information <br /> The Site is depicted on the Preliminary geologic map showing Quaternary deposits of <br /> the Lodi quadrangle, California (Marchand and Atwater, 1979). The Site is depicted <br /> within a map unit of the Riverbank formation middle unit, described as "arkosic alluvium <br /> forming Mokelumne River terraces and alluvial fan; chiefly sand; probably glacial <br /> outwash" (Plate 11). <br /> The surface and near surface soils located at the Site are reported by the USDA Web <br /> Soil Survey to be composed of the San Joaquin-Urban land complex (Plate 12) (USDA, <br /> 2019). The table below presents some selected properties of this soil: <br /> Table 1. Selected Properties of On-Site Soils (USDA, 1992) <br /> Soil Name and Depth Unified Soil Salinity Soil Perme- Septic tank <br /> Map Symbol (in) Classification mmhos/cm Reaction ability absorption <br /> pH (in/hr) fields <br /> San Joaquin- 0-16 Loam; CL-ML, ML <2 5.6-6.5 0.6-2.0 Severe: <br /> Urban Complex, 16-26 Clay loam, clay; CL <2 6.1-7.8 <0.06 cemented <br /> 0-2% slopes, 26-60 Indurated --- --- --- pan, peres <br /> 242 slowly <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 May 7, 2019, Live Oak excavated a shallow soil boring in 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, 3.10 feet deep, and was excavated by hand auger (Table <br /> 2). <br /> The location of the boring is indicated on Plate 13. <br /> The soil in the boring was similar to that described by the Soil Survey. Sandy clay vv�s1 <br /> encountered to the full depth of the hole. The soil log is 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 /> test is the only accepted method for determining the suitability of the soils for a septic <br /> disposal area. Percolation test results are discussed in the following section. <br /> LOGE 1920 Page 5 <br />