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. analvzed for toxicity by 96-hour static bioassay. The <br /> resulting LC-50 was greater than 1,000 ppm which classifies <br /> the soil as non-hazardous (see Table 3) . <br /> Based on these analyses, the soils were self-certified as <br /> non-hazardous and transported to the BJJ Company facility at <br /> 2431 East Mariposa Road, Stockton, Ca. The soils have been <br /> stockpiled on 6 mil plastic pending approval of a <br /> remediation and disposal plan. <br /> � r <br /> 3.2 Subsurface Conditions <br /> , m Soils from the excavation consist primarily of lean and fat <br /> clays 9.5 feet below grade, the maximum depth explored. <br /> Evidence of hydrocarbon odors and soil discoloration was <br /> noted from six feet to 9.5 feet below grade. Laboratory <br /> analysis of the soil samples indicates that petroleum <br /> hydrocarbons are present above minimum reporting <br /> requirements. <br /> 3.3 Groundwater Conditions <br /> Groundwater was encountered in the excavation at a depth of <br /> 9.5 feet below grade. Evidence of petroleum contamination <br /> was observed in saturated soils below 9 . 5 feet <br /> (discoloration, odor ) . Product sheens was observed in <br /> standing water within the excavation. <br /> I:ONCLUSZON,S AND RECOMMENDATIONS <br /> Because groundwater was observed to be in contact with <br /> contaminated soils, additional groundwater assessment is <br /> }� warranted. A minimum of two additional wells are necessary <br /> to determine the extent of groundwater contamination and the <br /> direction and gradient of groundwater flow. <br /> As discussed previously, some soil contamination above the <br /> water table was left in place due to the location of <br /> permanent utility structures to the north and south of the <br /> excavation. This remaining soil and its effect on <br /> groundwater conditions will be addressed as part of the <br /> groundwater investigation when considering contaminated <br /> soils below the water table. <br /> Workscope and methodology for additional well installation <br /> is presented in Section 5.0 of this report. Remediation and <br /> ultimate disposal of the excavated material will be <br /> addressed in separate correspondence. <br /> 4 <br /> OM <br />