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ca CVV: o \V 9 A S S O C I A T E S I N C GROUNDWATER FLOW DIRECTION Water levels were measured in monitoring wells MW 1, MW2, and MW3 on December 8, 2004 Depth to water (DTW) ranged from 28 64 feet below ground surface (bgs) to 29 19 bgs Water level elevations ranged from 35 76 to 35 81, representing an average increase in water table elevation of approximately 0 55 feet since September 2004 The water level data were used to develop the groundwater elevation contour map (Figure 3) Groundwater in the uppermost aquifer beneath the site flowed toward the northwest during the sampling event The average hydraulic gradient on December 8, 2004, was calculated to be 0 0006 or approximately 3 2 ft/mile A summary of groundwater monitoring data is presented in Table 1 ANALYTICAL RESULTS TPHg was detected in the groundwater samples collected from MW1, MW2, and MW3 at concentrations of 470 micrograms per liter (pg/L), 620 µg/L, and 1,800 pg/L, respectively Benzene was detected in the groundwater sample collected from MW3 at a concentration of 2 0 µg/L Toluene was detected in the groundwater sample collected from MWl, MW2, and MW3 at concentrations ranging from 0 6 to 2 7 pg/L Ethyl benzene was detected in the groundwater . sample collected from MW1, MW2, and MW3 at concentrations ranging from 3 2 to 22 µg/L Xylenes were detected in the groundwater samples collected from MW2 and MW3 at concentrations of 1 4 [Eg/L and 57 µg/L, respectively MTBE was not detected in the groundwater samples collected from MW1, MW2, and MW3 Analytical results of groundwater samples are summarized in Table 2 GEOTRACKER DATA UPLOAD The depth to water data was submitted electronically to the State Water Resources Control Board (S WRCB) Geotracker database (confirmation number 4146000504) and the laboratory data was also submitted electronically to the SWRCB Geotracker database (confirmation number 4201974451) The facility has been assigned a Geotracker global identification number T0607700395 Documentation of the data submittal is contained in Attachment 3 CONCLUSIONS Groundwater flow direction and gradient is generally consistent with previous sampling events Water table elevations have increased beneath the site since September 2004 Groundwater analytical results indicate that the concentrations of benzene detected in the samples collected from the monitoring wells have recently decreased but remain within historical parameters as set by previous groundwater analytical results This may be due to a rebounding effect following groundwater extraction activities and/or the historical low groundwater table • s lenvuonmentahI498 MeportsWQR-04 doe 3