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1 <br /> 22 September 1997 <br /> AGE-NC Project No 95-0167 <br /> Page 4 of 6 <br /> ' grade to depths of approximately ten feet bsg Tan, silty sand was encountered in bonng P3 at depths <br /> between 10 and 25 feet bsg Silty clay was encountered in boring P I from the surface to a depth of <br /> 15 feet bsg and sand was encountered in the same boring below the silty clay, from depths of 15 to <br /> approximately 25 feet bsg Soil boring logs are depicted in Appendix A <br /> ' 4 2 HYDROCARBON-IMPACTED SOIL <br /> TPH-g was detected in soil samples from probe boring P2, P3 and P7 at concentrations as high as <br /> ' 230 ppm (P3-10') BTE&X compounds were detected in soil samples collected from P3 at <br /> concentrations ranging from 0 010 (ethyl benzene, P3-25')to 19 ppm (xylenes, P3-10') <br /> Petroleum hydrocarbons were not detected in soil samples analyzed from any other probe borings <br /> advanced during this investigation Laboratory results of soil samples analyzed for petroleum <br /> ' hydrocarbons area summarized in Table I - Analytical Results of Soil Samples The laboratory <br /> reports(MAI Laboratory ID 56589 to 56598, 75759 to 75765),QA/QC reports and chain-of-custody <br /> forms are included in Appendix B <br /> ' Analytical results of soil samples submitted for physicochemical analysis and microbiological <br /> enumeration indicate that there is microbial activity at the site,however segregated from the area of <br /> ' the hydrocarbon release The lack of biodegrading bacteria in the area of the dispenser may be due <br /> to the presence of biotoxic compounds in the subsurface at the site, such as metals or pesticides <br /> However, adequate concentrations of necessary nutrients for microbe growth and sustenance were <br /> present in the soil at the site The microbiological laboratory report(A Keith Kaufman report dated <br /> 05 May 1997) and chain-of-custody form are included in Appendix C <br /> 4 3 HYDROCARBON-IMPACTED GROUND WATER <br /> TPH-g was detected in foui of six grab ground water samples collected from the site at <br /> concentrations ranging from 510 to 94,000 parts per billion(ppb, reported as micrograms per liter) <br /> BTE&X compounds were detected in five of six samples analyzed at concentrations ranging from <br /> 1 ' 1 3 ppb benzene in boring P 1 to 19,000 ppb of toluene in boring P6 MTBE was detected at <br /> concentrations up to 290 ppb <br /> ' No etroleum hydrocarbons were detected in the grab water sample collected from the City of <br /> p <br /> Stockton right-of-way in Fremont Street, located in the apparent up-gradient direction from the <br /> former UST area <br /> • Laboratory results of grab ground water samples analyzed for petroleum hydrocarbons are <br /> Advanced GeoEnvoronmentai,Inc <br />