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!Makk Inc <br /> Three 12,000 gallon underground fuel storage tanks, one leaded gasoline, one unleaded gasoline <br /> and one diesel, were excavated and removed from the property on January 8, 1992. The <br /> excavated overburden soil material was stockpiled adjacent to the excavation. Confirmation soil <br />' samples were collected from the bottom of the excavation and analyzed for concentrations of <br /> TPH, benzene, toluene, ethylbenzene and xylenes (BTEX), ethylene dibromide (EDB) and total <br /> lead Composite soil samples were collected from the stockpiled soil material for the same <br /> constituents. The results of the Treatek sampling are provided in the Treatek report dated <br /> January 28, 1992. <br /> Once the tanks were removed and all confirmation soil samples were collected, TreaTek <br /> personnel lined the bottom of the former tank excavation with black plastic sheeting and pushed <br /> the stockpiled soil material (the reported volume was 180 cubic yards) into the excavation A <br />' second layer of black plastic sheeting was placed over the top of the soil. <br /> McLaren/Har <br /> Soil sampling and monitor well construction were conducted at the subject site on November 3 <br /> through November 5, 1992 A total of five monitor wells were installed, MW 1 through MW4 <br /> along the perimeter of the former underground storage tank farm, and MW5 at the northeast <br /> corner of the subject site in the inferred downgradient direction. Soil borings were drilled to <br /> a maximum depth of 45 feet below ground surface, and monitor wells were installed within the <br /> boreholes to a maximum depth of 40 feet below ground surface <br /> The analytical results of the soil samples collected during monitor well drilling indicates that <br /> concentrations of TPH as gasoline (TPH-G) were detected in the soil collected from monitor <br /> wells MW2 through MWS. BTEX compounds were detected in the soil samples collected from <br /> monitor wells MW2, MW3 and MW4 The maximum concentrations of petroleum hydrocarbons <br /> detected in soil samples were from the samples collected at 25 feet below ground surface, at the <br /> historical highest seasonal groundwater elevation <br /> Groundwater samples were collected from the five monitoring wells on November 19, 1992 and <br /> submitted for laboratory analysis The analytical results indicated that no detectable <br /> concentrations of TPH were present in the groundwater samples collected from the five <br /> monitoring wells at the site. Concentrations of benzene were detected in groundwater samples <br /> collected from monitor wells MW2, MW3 and MW4 at 0 58 micrograms per liter or µg11, 7 7 <br />' µg/l and 18 µg11, respectively. Toluene and ethylbenzene were detected only in the groundwater <br /> sample collected from monitoring well MW4 at a concentration of 1.2 µg/l each. Xylenes were <br /> detected in groundwater samples collected from monitoring wells MW3 and MW4 at <br />' concentrations of 1.2 1Ag11 and 13.5 µg/l, respectively. <br /> Groundwater samples were collected again from the five monitor wells on June 4, 1993 to begin <br /> the quarterly sampling program. Concentrations of petroleum hydrocarbons as gasoline were <br /> detected in groundwater samples collected form monitoring wells MW1 and MW4 at <br />' m121cQ 3 <br />