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—CV o . A S S O C I A T E S I N C TPHg or oxygenate fuel additives Analytical results of groundwater samples are summarized in Table 2 Laboratory data sheets and chain-of-custody documentation are contained in Attachment 2 GROUNDWATER FLOW DIRECTION Water level measurements were collected from wells MW1 through MW8 on June 19, 2001 Water levels ranged from 60 29 to 61 65 feet below the tops of the well casing elevations, representing an average decrease in the water table elevation of approximately 0 26 feet since February 2001 The water level data were used to develop the groundwater elevation contour map (Figure 2) Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer beneath the site flowed towards the northwest The average hydraulic gradient on June 19, 2001 was calculated to be 0 004 ft/ft or approximately 21 1 ft/mile A summary of groundwater monitoring data is presented in Table 1 CONCLUSIONS Concentrations from wells MW 1 through MW6 and MW8 remain consistent with the results from the previous sampling event Concentrations in well MW7 decreased by at least one order of magnitude The direction of groundwater flow was consistent with the previous monitoring event Groundwater elevations have decreased since February 2001 RECOMMENDATIONS Based on the results of the second quarter 2001 monitoring episode, we recommend the following • Installing additional soil borings south, east, and north of the existing groundwater monitoring wells to attempt to evaluate the lateral extent of impacted soil and groundwater • Performing vapor extraction and air sparge pilot testing at the site to evaluate them as potential remedial options + Conducting the Third Quarter 2001 groundwater monitoring and sampling of wells MW1 through MW8 and DW and analyze samples for TPHg, BTEX, and oxygenate fuel additives w 1163931quartlyl2gr-2001 doc 3