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Mr. Ron Rowe <br /> March 9, 1998 <br /> Page 4 <br /> A TPHg concentration of 5,900 ppb was observed in the groundwater grab sample from CPT-3 at a depth of <br /> 49 feet bgs. TPHg concentrations were not observed above the detection limit in the groundwater grab sample <br /> collected from CPT-3 at a depth of 92 feet bgs. Benzene concentrations decreased from 1,100 ppb to 6.3 ppb <br /> in the groundwater grab samples collected from CPT-3 at depths of 49 and 92 feet bgs, respectively. At a <br /> depth of 49 feet bgs, toluene, ethylbenzene, and xylenes were observed at concentrations of 21,non-detect, <br /> and 62 ppb, respectively. Toluene, ethylbenzene, and xylenes were not detected in the groundwater grab <br /> sample collected at 92 feet bgs in CPT-3. MTBE was not detected in all three groundwater sample collected <br /> from CPT-3. <br /> CONCLUSIONS <br /> Based on the analytical results of grounndwater and soil samples collected during the CPT survey, SECOR <br /> concludes that vertical extent of petroleum hydrocarbon-affected groundwater underlying the Site has been <br /> adequately characterized. Three samples were collected near the bottom of soundings CPT-1 through CPT-3 <br /> at 125 (soil), 102, and 92 feet bgs, respectively. The analytical results for TPHg, toluene, ethylbenzene, <br /> xylenes, and MTBE were all below the detection limits in these groundwater and soil samples, The only <br /> analyte detected in these three deepest samples was benzene at a concentration of 6.3 ppb in the 92 feet bgs <br /> sample collected from CPT-3. Due to the decrease in benzene concentrations between the 49 feet bgs (l.,100 <br /> ppb) and 92 feet bgs (6.3 ppb), it is not anticipated that hydrocarbon-affected groundwater would be <br /> encountered at depths exceeding those explored during this investigation. <br /> 1f you have any questions or comments regarding this report,please do not hesitate to contact us at(415) 882- <br /> 1548. <br /> Sincerely, <br /> SECOR International Incorporated <br /> NaY r <br /> A. Bond Bruce E. Scarbrough,R.G, <br /> Project Manager Principal Geologist <br /> cc: Mr. Christopher Rants,Metz Baking Company <br /> Tables: Table 1 - Groundwater and Soil Laboratory Analytical Results <br /> Figures: Figure 1 -Site Location Map <br /> Figure 2- Site Plan with CPT Locations <br /> �{ Figure 3 - Site Plan with Cross-Section Locations <br /> Figure 4-Generalized Geologic Cross-Sections <br /> Attachments: Attachment A- Cone Penetration Test Data <br /> Attachment B -Groundwater and Soil Sample Laboratory Analytical Reports and Chain-of- <br /> Custody Records <br /> H:ISI'MSTOCKTOWPTSURV22PT SECOR International Incorporated <br /> _I <br />