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i ' 20 October 2003 I ! AGE-NC Project No 97-0301 Page 4of5 • The ground water elevation at the site was generally only 1 to 2 feet above the screened intervals of wells MW-1 through MW-4,MW-6, and MW-7,and should yield samples fully representative of shallow ground water conditions, however, the water level in well MW-5 was approximately 48 feet above the screen interval and yielded a sample more representative of deeper ground water conditions • The core of the dissolved petroleum hydrocarbon plume appears to be distributed near the ' location of well MW-1, at well MW-7 and north to a yet undetermined distance down gradient Analysis of ground water samples collected from MW-1 and MW-7 indicate that the core of the plume is impacted by TPH-g, TPH-d, TPH-k, BTE&X and 1,2-DCA CF W'. • Substantial concentrations of dissolved TPH-mo have previously been detected in water samples collected from well MW-4 (screened 30 to 50 feet bsg) and from well MW-5 ' (screened 80 to 90 feet bsg),indicating a limited distribution of TPH-mo to the area assessed • BTE&X and 1,2-DCA concentrations in ground water samples MW-1 and MW-7 were substantially above their respective Maximum Contaminant Levels in drinking water • Very low concentrations of MTBE, EDB and TBA have been detected at MW-1 indicating that there is only a minor impact of these components ' The vertical extent of dissolved petroleum hydrocarbons is not fully defined at the site (Figures 4 and 5) The lateral extent of the dissolved petroleum hydrocarbon plume is not ' fully defined toward the southeast, east and northeast of the current area bound by wells MW-1 through MW-7 5.0. RECOMMENDATIONS ' Based upon data collected during June 2003, AGE recommends • Continued ground water monitoring utilizing wells MW-1 through MW-7 The next quarterly ' groundwater monitoring events are tentatively scheduled for September and December 2003 or after the installation of any new wells and should be performed concurrently with the ' California Tank-Line Inc site (3105 South El Dorado Street) I ' 6.0. LIMITATIONS Our professional services were performed using that degree of care and skill ordinarily exercised by ' environmental consultants practicing in this or similar localities The findings were based upon . analytical results provided by an independent laboratory Evaluation of the hydro geologic conditions ' Advanced GeoEnvtronmeatal,Inc