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N) CONESTOGA-ROVERS &ASSOCIATES November 2004 Dispenser Replacements: Cambria Environmental Technology, Inc. (Cambria) collected native soil samples from beneath the former dispensers at depths of approximately 5 to 8 feet below grade (fbg). Total petroleum hydrocarbons as gasoline (TPHg)was detected in two soil samples at concentrations of 1.9 and 340 milligrams per kilogram (mg/Kg). Benzene was detected in two soil samples at concentrations of 0.61 and 0.011 mg/Kg. Total petroleum hydrocarbons as diesel (TPHd) was detected in two soil samples at concentrations of I1 and 33 mg/Kg. MTBE was detected in six soil samples at concentrations ranging from 0.018 to 0.44 mg/Kg. Tertiary butyl alcohol (TBA)was detected in five soil samples at concentrations ranging from 0.011 to 0.020 mg/Kg. No other fuel oxygenates, 1,2-dichloroethane (1,2-DCA), or ethylene dibromide (EDB) were detected in soil samples collected from beneath the dispensers. These activities were documented in Cambria's January 20, 2005 Dispenser Upgrade Sampling Report. November 2004 Sensitive Receptor Survey: Cambria performed a sensitive receptor survey in the vicinity of the subject site. In the Sensitive Receptor Survey Report and Site Investigation Work Plan submitted November 18, 2004, Cambria identified two domestic water wells approximately 1,300 feet southwest and 1,900 feet east of the site. These wells are approximately 220 and 180 feet deep and screened from 195-220 and 157-177 fbg,respectively. Included in the November 18, 2004 report was the results of a well survey performed by SECOR for the 7-Eleven site. Five private wells were identified by SECOR on Corral Hollow Road (greater than 1,700 feet east of the 7-Eleven site) and one private well was identified on Toste Road, southwest of the 7-Eleven site. No surface water bodies were identified within a 2,000-foot radius of the site. The locations of these wells are depicted on Figure 1. January and March 2005 Site Investigation: Cambria installed wells MW-5 through MW-7 and drilled soil boring S13-1. The purpose of this investigation was to further assess the horizontal and vertical extent of gasoline constituents in soil and groundwater beneath the site. The investigation findings indicated that no TPHg or benzene is present in soil or groundwater beneath the site. Only MTBE was detected in some of the soil samples collected during this investigation. These detections of MTBE were in saturated soil samples and are likely the result of horizontal migration of impacted groundwater rather than the result of vertical migration from vadose soils. The highest levels of MTBE in soil were detected in soil samples from MW-6 which is located downgradient of well MW-1. Water samples from SB-1 collected at 52, 72, and 1661 Z Worldwide Engineering,Environmental,Construction,end IT Services