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CSG A 1998 Site Investigation: During February 1998, Cambria drilled two cone penetration test (CPT) borings (CPT-1 and CPT-2) and installed six groundwater monitoring wells (S-1 through S-6). During this investigation, soil samples were collected at depths of 40, 51, and 60 feet below grade (fbg) in boring CPT-1 and at 40, 52, and 58 fbg in CPT-2. No TPHg, benzene, toluene, ethylbenzene, xylenes (BTEX), or fuel oxygenates were detected in soil from these borings. Therefore, these borings delineate these constituents in soil above 40 fbg. TPHd was detected at 1.6 ppm at 51 fbg in CPT-1 and at 2.0 ppm at 52 fbg in CPT-2. Therefore, CPT-1 and CPT-2 also delineate TPHd in soil above 60 and 58 fbg, respectively. Soil samples collected from well boring S-2 contained TPHg concentrations of 28 ppm at 25 fbg and 570 ppm at 30 fbg. TPHg was not detected in soil collected from the other well borings. No benzene or fuel oxygenates (by EPA Method 8260) were detected in soil from any of the well borings. These activities are documented in Cambria's July 14, 1998 Site Investigation Report. Groundwater Monitoring Program: There are currently four monitoring wells onsite (S-1 through S-4) and two offsite monitoring wells (S-5 and S-6), located north of the subject site in Elmwood Avenue. Currently wells S-1 through S-4 are monitored and sampled quarterly and wells S-5 and S-6 are monitored and sampled annually. During the third quarter 2002 sampling • event, TPHg was detected in wells S-1 through S-3 at concentrations ranging from 170 to 7,900 ppb. Benzene was detected in wells S-1 and S-2 at 27 and 5.7 ppb, respectively, and 61 ppb TPHd was detected in well S-3. During the same event, 350 ppb MTBE and 85 ppb tertiary butanol were detected in well S-2. Wells S-5 and S-6 were not sampled during the third quarter 2002 sampling event. RESPONSE TO SJCEND LETTER Waste Oil Investigation In the correspondence dated October 11, 1996, San Joaquin County Public Health Services, Environmental Health Division (SJCPHS/EHD) requested that Shell perform a soil and groundwater investigation in the vicinity of the former waste oil tank. Specifically, SJCPHS/EHD requested that Shell analyze soil samples for cadmium, chromium, lead, nickel, zinc, oil and grease, chlorinated hydrocarbons, polychlorinated biphenyls (PCBs), pentachlorophenol (PCP), polynuclear aromatics (PNAs), and creosote. SJCPHSIEHD further requested that these also be analyzed in groundwater, if they were detected in soil. SJCEHD's September 20, 2002 letter states that"this requirement has not been met." • 0943 3