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CAM RIA i 1996 Tank Replacement: In April 1996, Cambria collected samples during the replacement of the USTs, dispenser islands, and product lines at the site. Total petroleum hydrocarbons as gasoline (TPHg) and benzene were detected in only one soil sample (S-2) collected at 9 feet below grade (fbg) beneath the southeast dispenser. The area was subsequently over-excavated to a depth of approximately 18 feet, which was the maximum depth possible with the equipment available and site construction constraints. The soil sample collected at 18 fbg (X-2) contained 3,500 parts per million (ppm) TPHg, 43 ppm benzene, and 0.250 ppm methyl tertiary butyl ether (MTBE). Soil sampling locations are shown on Figure 2, and soil analytical results are summarized in Table 1. The sampling, excavation, and analytical results were described in Cambria's July 25, 1996 Tank Removal and Soil Sampling Report. 1998 Groundwater Monitoring Well Installation: In March 1998, Cambria installed one groundwater monitoring well (MW-1) near the southwest dispenser island at the site (Figure 2). No TPHg, benzene, toluene, ethylbenzene, or xylenes (BTEX) were detected in soil samples collected during MW-1 installation. Up to 11.0 ppm MTBE was detected in soil samples collected between 23.5 and 33.5 fbg, at or below the typical groundwater depth at the site. Soil • analytical results are summarized in Table 1. Investigation activities were described in Cambria's April 28, 1998 Well Installation Report. 1998 Conduit Study and Well Survey: In July 1998, Cambria completed a utility study and well survey for the site vicinity. The only utility line identified in the site vicinity which may encounter groundwater is a sanitary sewer located beneath Manley Road at an approximate depth of 18 to 20 fbg. Manley Road is located approximately 1,200 feet east of the site. Cambria reviewed City of Ripon, San Joaquin County, and California Department of Water Resources (DWR) data to complete the well survey. Several wells were identified in the site vicinity, including a well located on the property immediately west of the site (Den Dunk well), a Caltrans well located southeast of the site, and seven City of Ripon municipal wells. The conduit study and well survey were originally reported in Cambria's July 10, 1998 Investigation Work Plan Addendum#4. In July 1998, Cambria sampled the closest identified wells, the Den Dunk well and the Caltrans well, for TPHg, BTEX, MTBE, and fuel oxygenates. None of the analytes were detected in crrnnnrlwater camnlac rnllerterl from either well. Samnlinn activities were described in Cambria's August 17, 1998 CPT Investigation Report. In March 2005, Cambria reviewed and . updated the original well survey. Approximate well locations are shown on Figure 1, and the 0324 2