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06 February 2003 AGE-NC Project No. 98-0504 Page 2 of 9 Based upon ground water monitoring well information obtained from 248 West Harding Way(300 feet west of the site), ground water flow direction is northeasterly to easternly and currently occurs at a depth of approximately 25 feet below surface grade (bsg) within ground water wells. Ground water occurs in a genbrally sandy layer extending from approximately 35 feet bsg to 45 feet bsg (248 West Harding). The sedimentary units are thought to be relatively horizontal and continuous over the area. 2.2. UNDERGROUND STORAGE TANK REMOVAL Two USTs, dispenser island and associated piping were removed from the site on 22 September 1998. four soil samples were collected beneath the USTs, one sample was collected beneath the dispenser area and three laboratory-composited soil samples were collected from the excavated soil. Methyl t ertiary b utyl e they (MTBE) a nd t ertiary b utanol (TBA) w ere d etected i n s oil s ampler collected from beneath the USTs and dispenser island at concentrations up to r rte_ 39 milli'urams/kilograms(mg/kg);total petroleurn hydrocarbons quantified as gasoline(TPH-g)were; detected at concentrations up to 1,400 mg/kg; and volatile aromatics (benzene, toluene, ethyl benzene and xylenes: BTEX) were detected at concentrations up to 1.90 mg/kg. Approximately 200 tons of soil were excavated during removal of the USTs. After removal of the USTs was completed, the soil was placed back into the excavation because of strong hydrocarbon odors and the proximity to a school. Two laboratory-composi.ted samples were collected from the stockpiled soil prior to placement into the excavation. TPH-g,BTFX and MTBE and TBA were all detected in the composite samples. 2.3. SOIL OVER-EXCAVATION On 10 November 1998,approximately 250 yards ofhydro carbon-impacted soil were excavated from the location of the former UST system, utilizing a backhoe with an approximate 15-foot reach capability. The excavated soil was field-screened for the presence of volatile organic compounds using an OVM, and stockpiled on the eastern edge of the site. Approximately 150 yards of soil was loaded and transported to Forward Inc. Landfill under manifest for proper disposal on 10 November 1999;an additional 100 yards of impacted soil were transported to Forward Inc. Landfill for disposal on 14 December 1999. A total of nine soil samples were collected from the floor and sidewalls of the over-excavation using a backhoe TPH-g and BTEX compounds were detected only in samples collected from the north wall, east end and west wall, north end of the excavation at concentrations up to 80 mg/kg TPH-g Advanced GeoFnvironrnentai,Inc.