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C:A ASSOCIATES I N C . GROUNDWATER FLOW DIRECTION Water level measurements were collected from wells MWI through MW5, MW6a, MW6b, MW7a, MW7b, MW7c, MW8, MW9a, MW9b, MW9c, and EW1 on March 16, 2004. Water levels in the monitoring wells screened in the shallow water bearing zone ranged from 64.17 to 65.14 feet below the tops of the well casing elevations. The water level data were used to develop the groundwater elevation contour maps for the shallow (A), intermediate (B), and deep (C) groundwater zones (Figures 3 through 5). Assuming that horizontal isotropic conditions prevail, shallow groundwater beneath the site flowed towards the northeast. The average hydraulic gradient on March 16, 2004, was calculated to be 0.0003 ft/ft or approximately 2 ft/mile. Assuming that horizontal isotropic conditions prevail, intermediate zone groundwater beneath the site flowed towards the northwest and deep zone groundwater flowed towards the southeast. A summary of groundwater monitoring data is presented in Table 1. ANALYTICAL RESULTS The groundwater samples collected from wells MWI through MW4, MW8, and EW1 contained detectable concentrations of TPHg and BTEX constituents. Groundwater samples collected from wells MW5 and MW6a contained detectable concentrations of TPHg but no BTEX constituents. • Groundwater samples from wells MWI through MW9c and EW1 did not contain detectable concentrations of TPHd. Groundwater samples collected from well MW9c contained detectable concentrations of benzene, toluene, and xylenes. Groundwater samples collected from wells MW6b, MW7a, MW7b, MW7c, MW9a, and MW9b contained no detectable concentrations of TPHg or BTEX constituents. Groundwater samples collected from MWI, MW2, MW4, MW6b, MW7c, MW8, and EW1 contained detectable concentrations of MTBE and groundwater samples from well MW4 and MW6a contained detectable concentrations of TBA. Groundwater samples collected from wells MWI and MW4 contained detectable concentrations of 1,2-DCA. Analytical results of groundwater samples are summarized in Table 2. Laboratory data sheets and chain-of-custody documentation are contained in Attachment 2. CONCLUSIONS Concentrations of petroleum hydrocarbons in samples collected from the shallow groundwater zone on-site remain elevated. Concentrations of petroleum hydrocarbons in samples collected from the deep groundwater zone are elevated on-site. Concentrations of TPHg and TBA detected in the groundwater sample collected from MW6a indicate the hydrocarbon plume extends off- site in the shallow aquifer. Concentrations of BTEX, MTBE detected in the groundwater sample collected from MW6b, MW7c, and MW9c indicate the hydrocarbon plume extends off-site to the east and in deeper groundwater. S:1268231QM reports12004 1QR.doc 3