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SOIL AND GROUNDWATER SAMPLING H = I Former Parts Depot, Stockton, CA October 2009, Page 3 of 3 SOIL PILE One near-surface soil sample was collected from soil piled near the northwestern comer of the facility property.The source of the soil pile is unknown. It is approximately two to three feet high and covers an area of approximately 300 to 400 square feet.The soil pile sampling location is shown on Figure 1 and is depicted in the photo shown in Attachment A. The pile contained soil similar in color and texture to the soil observed in the nearby borings,was covered with vegetation,and contained animal burrows.The sample was collected near the top of the pile,and was analyzed for the same parameters that were analyzed for the samples collected along the western property boundary. Arsenic,barium,chromium,mercury and lead,methylene chloride,and indicator parameters were detected in the soil pile(Table 1; Attachment Q.Methylene chloride exceeded the U.S. EPA RSL,and was the only VOC to do so. Semivolatiles were not detected. Arsenic and barium were found in the soil pile at 4.7 and 140 mg/kg,respectively, with arsenic exceeding the U.S. EPA RSL for the protection of groundwater. The chemistry of the soil pile appear to be different than the chemistry of soil from the western property boundary. For example,lead was found at 25 mg/kg in the soil pile, whereas the soil samples collected along the western property boundary contained lead between 3.9 and 8.5 mg/kg. Similar comparisons can be made for sulfate,nitrate and chloride. SUMMARY Soil samples collected near the septic field did not contain VOCs or SVOCs. Three soil samples from the western side of the subject property contained chloroform at levels that exceed U.S. EPA's RSLs.Acetone was found at levels below the lowest RSL. It is likely that the acetone and chloroform originated at the neighboring property to the west. The occurrence of chloroform may be the result of a reaction between acetone and sodium hypochlorite. Arsenic and barium were also found near the western property boundary at concentrations that exceed U.S. EPA RSLs. The chemistry of the soil pile near the northwest corner of the subject property suggests that it did not originate along the western property boundary. Methylene chloride,barium,and arsenic levels exceeded RSLs.