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January 11, 2022 <br />BGG No. G130.09B <br />GROUNDWATER INFORMATION <br /> <br />Groundwater Depth and Gradient <br />We reviewed ground water elevation information available from the California Department of Water <br />Resources Water Data Library (CA WDL) and the San Joaquin County Flood Control and Water <br />Conservation District (SJCFCWCD) to determine the ground water levels near the Site. Recent data <br />indicates that ground water at the site is approximately 20 to 25 feet below ground surface (bgs) and <br />ground water flows predominantly toward the south-southeast. A detailed evaluation of these and <br />other factors, which may be responsible for groundwater fluctuations, was beyond the scope of this <br />study. <br /> <br />Potential Ground Water Contamination Issues <br />The Soil Suitability Study is not intended to serve as an investigation into groundwater <br />contamination sources, and no such investigation was conducted. Many sources can contribute to <br />ground water contamination, including underground storage tank leaks, agricultural applications, <br />dairy activities, septic systems, and storm water infiltration. <br /> <br />BGG reviewed the SJCEHD Water Well Data Table dated March 10, 2009 for nearby addresses that <br />have been tested for nitrate and dibromochloropropane (DBCP), which are identified groundwater <br />contaminants in San Joaquin County. The Maximum Contaminant Level (MCL) established by the <br />US EPA for nitrate as NO3 is 45 mg/L (10 mg/L-N) and the MCL for DBCP is 0.2 µg/L. For wells <br />identified within approximately 1 mile of the subject site, the following summarizes the reported <br />results: <br /> Nitrate was detected in the wells identified, at concentrations of 25.0 to 48.0 mg/L-NO 3. <br /> DBCP was not detected. <br /> <br />Wells Onsite <br />A new domestic water well was recently drilled at the site for the new residence. No well permits <br />were identified for the site from among files at the San Joaquin County Environmental Health <br />Department. <br /> <br />Water Sample <br />The new well located at the site was recently tested at the time of installation; hence, a water sample <br />was not collected for this study. <br /> <br />SOIL PROFILE AND GEOLOGIC SETTING <br /> <br />The site is shown on the Geologic map of the San Francisco-San Jose quadrangle of California <br />(Wagner, et al., 1991) to be underlain by Holocene age alluvial fan deposits. <br /> <br />According to the USDA Web Soil Survey, the proposed residence site is mapped as being mantled <br />by the Delhi Loamy Sand soil series. In the upper 2 feet below the ground surface (bgs), this soil <br />series is reported to consist of Silty Sand and have 100% passing the No. 4 sieve (sand-sized <br />particles), contain 27 to 31 percent fines (silt- and clay-sized particles), and be nonplastic. Silty <br />Sand to Poorly Graded Sand is reported between about 2 to 5 feet deep. The saturated hydraulic