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Labs to form a composite sample of that gnd line (Example, samples Al, A2, and A3 were combined to form one composite sample) The "A" line 19 mg/kg of kerosene and 38 mg/kg of motor oil The composite of`B" line was 10 mg/kg of kerosene and 290 mg/kg motor oil Line"C" composite had . a result of 6 mg/kg of kerosene CONCLUSIONS The project reached its main objective to remove all soils in the area that could contaminate the water table The bottom of the excavation was ten feet below the historic water table elevation and was clean to standard acceptable levels Some areas of contamination remain in the side walls of the excavation The north wall of the excavation contained the highest concentrations of contamination at a depth of 20 to 25 feet The south wall had only one sample that showed any significant levels of hydrocarbons present at 900 mg/kg The east and west wall of the excavation had one sample each that show significant levels of hydrocarbons The stockpile of excavated soils when sampled showed very low levels of the kerosene fractions and low levels of motor oil (See test results for Sample # 31, 32, 33) The lighter gasoline and BTEX fractions may have evaporated during excavation and stockpiling operation High volumes of vapor were present in the excavation during that operation DISPOSAL OF EXCAVATED SOILS STOCKPILED ON THE SITE The stockpiled soils excavated from the former UST site present a very Iow danger to the under ground water supplies in the area It is recommended that the stockpiled soils be spread over the Holt Bros property to a depth of 1 S' and shaped to drain Resampling of the excavated soils can be done before any movement,if required by PHS/EHD All underlining plastic sheeting should be removed and disposed of at an approved disposal site Answers to questions or requests for additional information should be directed to Ervin Rifenburg at Foothill Engineering, phone number (209) 368-9381 Respectfully submitted, OQR3 WFE�BU �� l Foot gine ng U a No 1975 Ex Ervin Rifenburg, P OFCAL1C��P AMR Attachments Maps, Test results, Chain of Custody CC Fritz Baker, Project Manager Holt Bros CRWQCB, Central Valley Region 4