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• EXECUTIVE SUMMARY <br /> Upgradient Environmental Consultants drilled two borings at the Valley Motors dealership during <br /> the third quarter, and analyzed eight soil samples for the presence of hydrocarbon contaminants <br /> One of the borings was converted to a vapor extraction well, and the other was converted to an air <br /> spargmg well The vapor well was completed with 4-inch PVC casing, slotted from 15 to 30 feet <br /> The sparging well was completed with 2-inch casing, from 28 to 30 feet <br /> Groundwater momtonng took place on October 6, and four water samples were collected Neither <br /> of the two new wells contained water,because the static water level was below 30 feet <br /> Approximately 55 gallons of purged water was stored on site <br /> A sensitive receptor survey was also performed The survey consisted of a file review at the DWR <br /> in Sacramento and a walking tour of the area near the site to locate wells or other potential <br /> contaminant receptors <br /> The data obtained from the two new borings imply that soil contamination is more limited(or <br /> discontinuous)than previously thought No hydrocarbons were detected in any of the samples from <br /> the vapor well, and concentrations were lower than expected in the samples from the sparging well <br /> Benzene is the principal contaminant of concern, no gasoline oxygenates were detected <br /> • The depth to groundwater increased slightly since the last monitoring in May, to an average depth <br /> of 32 feet The groundwater flow direction has remained constant, and is still to the east <br /> Hydrocarbon concentrations continue to rise in VM-1 and VM-2, and have now risen above <br /> detection limits in VM-3 Concentrations in VM-4 appear to be on a generally decreasing trend <br /> None of the wells contained detectable concentrations of any of the oxygenates, and we recommend <br /> discontinuing analysis for these compounds <br /> There are four domestic water wells listed in the DWR files within a 2,000-foot radius of the site, <br /> but none of these are likely to affect contaminant migration or become impacted by contamination <br /> migrating from Valley Motors Three of the wells are located to the west of the site (upgradient), <br /> and the fourth is located to the north(cross gradient) All are more than 1,500 feet from the site, and <br /> are perforated in deeper aquifers Moreover, other contaminated sites are present between them and <br /> Valley Motors, and pose a greater threat <br /> i <br /> 1 <br />