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McDowell& Davis Towing Quarterly Groundwater Sampling Report March 2001 Page: 2 SUMMARY FINDINGS Groundwater was present as an unconfined state at a depth of 61 feet below ground surface at the McDowell &Davis Towing site on March 5, 2001. Groundwater Elevations 3-5-01 Well Collar Elevation DTW GW Elevation MW-1 118.14 61 57.14 MW-2 118.79 61.3 57.49 MW-3 118.39 61.58 56.81 Groundwater flow was to the northwest with a very shallow gradient (0.014 fVft). The potentiometric surface and groundwater flow direction are shown on Figure 2 Site Map / Groundwater Flow. Laboratory analysis were non detect for gasoline and all of gasoline constituents except Toluene. Toluene was disclosed in two of the three wells at concentrations well below drinking water standards. The dissolved oxygen concentrations shows a very slight decrease (7.3 to 7.0) in the down gradient direction which indicates that limited biologic activity in the area of the soil contamination. The minimal of increase in biologic activity suggests that that the release has not caused a significant groundwater impact. t` Laboratory Groundwater Sample Results 03-05-2001 Sample I.D. I Gasoline Benzene I Toluene t E-Benzene I Xylenes I Oxygenates C Z MW-1 ND ND ND ND ND ND 7.2 MW-2 ND I ND 10.3 ND ND ND 7.3 MW-3 ND I ND 10.4 1 ND ND i ND 7.0 ND=Non Detect NA=Not Analyzed Mg/i,for gasoline Erg/I,for BTEX,MTBE,and 8260 Oxygenated Compounds Gasoline and gasoline constituents were recognized at depths of 15 and 25 feet in one boring in the vicinity of the former dispenser island in an earlier investigation. The contamination was not recognized at depths greater than 25 feet. The limited extent of the i release does not appear to have affected the relatively deep unconfined groundwater at concentrations that threaten the beneficial uses of the water. Additional monitoring of the existing wells for a hydrologic cycle is recommended to confirm this finding. Groundwater monitoring is tentatively scheduled for June 2001. The above represents our best professional opinion as to environmental conditions at this site. These opinions were derived using data at hand, and standards of care common to the environmental consulting community in Northern California. There is the possibility that even with proper application of the above methodologies, there may exist on the subject property conditions that could not be identified within the scope of this sampling t work or which were not reasonably identifiable from the available information. The