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L ATC A S S O C I A T E S I N C wells MW1, MW2, MW3, and MW5 at concentrations of 2.0 µg/L, 6.7 µg/L, 2.7 gg/L, and 2.3 pg/L, respectively. TBA, DIPE, ETBE, TAME, 1,2-DCA, and EDB were not detected at or above the laboratory reported detection limit in any of the samples. Analytical results of groundwater samples are summarized in Table 2. Laboratory data sheets and chain-of-custody documentation are contained in Appendix C. Isoconcentration maps depicting the benzene and MTBE concentrations detected in groundwater samples collected on January 26, 2005, are shown on Figures 4 and 5, respectively. 4.0 GROUNDWATER FLOW DIRECTION Water level measurements were collected from wells MW 1 through MW3 and MW5 through MW8 on January 26, 2005 prior to collecting samples from these wells and prior to development of wells MW7 and MW8. The water level measurement data collected on January 26, 2005 were used to evaluate the groundwater flow direction. Water levels in shallow groundwater measured 6" on January 26, 2005, ranged from 7.52 to 9.00 feet below the tops of the well casing elevations. The water level data collected on January 26, 2005, were used to develop the groundwater elevation contour map (Figure 3). Shallow groundwater flow beneath the site is generally toward the north. The average hydraulic gradient on January 26, 2005, was calculated to be approximately 0.0017 ft/ft or approximately 9.0 ft/mile. A summary of groundwater monitoring data is presented in Table 1. V!r 5.0 GEOTRACKER DATA UPLOAD The monitoring well survey data were submitted electronically to the State Water Resources Control Board (SWRCB) Geotracker database (confirmation number 1863728165). Depth to water data and the laboratory analytical data associated with the first quarter 2005 sampling event were also submitted electronically to the SWRCB Geotracker database (confirmation numbers 6831906139). Documentation of the data submittal is contained in Appendix D. 6.0 CONCLUSIONS AND RECOMMENDATIONS The laboratory analytical results of the groundwater samples collected on January 26, 2005, are generally consistent with recent historical results. Well MW4 was below water and was not monitored or sampled during this current groundwater monitoring event. The groundwater elevation has increased on an average of 0.21 feet since the November 2004 groundwater monitoring event. The groundwater gradient direction is consistent with previous sampling events. Based on recent groundwater quality data associated with groundwater samples collected from the site, ATC recommends to continue quarterly groundwater monitoring during the second quarter 2005 and surveying the wells by a certified land surveyor according to SWRCB standards. ATC anticipates conducting the second, third, and fourth quarter groundwater monitoring events Lam- for the year of 2005, if petroleum hydrocarbons dissolved in groundwater are not detected in future samples collected from the downgradient wells (MW6, MW7, and MW8), ATC recommends no further action for the site. SAEnviromenta1\17861-Glover\REPORTS\2005QMR1 andwellinstallreport.doc 5 v