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r r 25 January 2005 r ry AGE-NC Project No 99-0559 Page 3 of 12 rThe general groundwater flow direction for HU l/HU2 was towards the west-northwest and and the ground water flow direction was calculated to be north or northwest In the lower flow units (HU3 rto HU6) Approximately six inches or less of free-product has been intermittently observed In well MW-2 and I lesser volumes have been detected In well MW-1 and MW-3 The highest concentrations of dissolved total petroleum hydrocarbons quantified as gasoline (TPH-g) and MTBE have been documented in the area of the former UST and approximately 75 feet southwest of the suspected I release The highest concentrations of MTBE have been detected in samples from well MW-2 at the former UST release area TPH-g and benzene have been detected at concentrations as great as 870,000 microgram pre liter (µg/1) and 48,000 µg11, respectively in May 2003 The last samples collected from each of the four shallow wells contain benzene above 6,000 µg/l and TPH-g at concentrations greater than 170,000 pig/l, further MTBE was detected above 2,200 I µg11 The highest concentrations of petroleum hydrocarbons detected in the CMT wells at the site were ' present in the ground water samples collected from wells screened in HU 1 and HU2 at the east edge of the UST area(MW-7) The well MW-8 also had detectable concentrations of BTEX compounds during sampling Variable concentrations of low BTEX values were detected in well MW-5 and r moderate concentrations of MTBE were also detected in the upper screen of the well Low to moderate, yet stable concentrations of BTEX compounds were detected in well MW-6, also moderate concentrations of MTBE were also detected in the upper screen of the well MW-6 with Ilower concentrations detected to the lower screened wells of MW-6 The fuel additives TAME,ETBE and 1,2-DCA were detected in samples from the former UST area, Iand down-gradient of the UST area (MW-4/MW-6) The vertical extent of impacted ground water, has been defined at the perimeter of the site, the r vertical extent of impacted ground water at the western and southern edge of the site are defined by well MW-5, and to a lesser degree by MW-6 The vertical extent of impacted ground water, at the former UST area, has not been defined and extends beyond the vertical depth of well MW-7E The lateral extent of shallow impacted ground water towards the west and southwest,down-gI adient of the UST area, has not been defined I r rAdvanced GeoEnvlronmentat,Inc r