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t Report: Groundwater-quality Monitoring—July 30,2003: 7500 West Eleventh Street, Tracy, CA. Page 7 Assume relative proportions of diesel and gasoline in the floating product in Monitoring Well MW-7 are in the same ratio as the concentrations of diesel and gasoline in the sample of groundwater recovered from that well on December 13, 2001. They were, respectively, 800,000 µg/L and 61,000 gg/L. (See Table 2.) Thus, the estimated specific gravity of the floating product in well MW-7 is: PP W 0.83 The depression in the elevation of the water table due to the presence of floating product is given by: f W=T (Pp /p,u) (Equation 1) Where: W= the depression of the water table 1 T = the thickness of floating product in the monitoring well PW = the specific gravity of the groundwater Pp = the specific gravity of the floating product Thus, in the case of the floating product measured in well MW-7 on July 30, 2003: W=0.33 (0.83/1.0) = 0.27 ft. Accordingly, when drawing the contours shown on Figure 2, the elevation of the groundwater in well MW-7 was based on an assumed depth to groundwater of 8.81 ft. rather than the depth of 9.08 ft. actually measured. This yields a corrected groundwater table elevation of 39.41 ft. MSL (which is shown on Figure 2) compared to the uncorrected value of 39.14 ft MSL given in Table 1. In addition, the groundwater elevations in Wells MW-3A, MW-3B and MW-12A were not considered when the groundwater contours were drawn because, although small in magnitude, differences between the elevations of the groundwater in Wells MW-3, MW- 3A and MW-3B and in MW-12 and MW-12A are sufficiently great to indicate that the groundwater monitored by the shallow well at the locations of each of those well clusters has different pieziometric pressure than that of the deeper wells in the same cluster. It must therefore be assumed, at least locally, that the shallow wells monitor aquifers different from those monitored by the deeper wells. During the July 30, 2003 sampling round, the groundwater level in Monitoring Well MW-3B, which is screened in an aquifer the top of which is some 37 ft. BGS, was 0.01 ft. lower than that in Monitoring s Well MW-3, which is screened in the shallow, near-surface aquifer, while the level in E; Monitoring Well MW-3A was 0.03 ft. higher than that in Monitoring Well MW-3. sic