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' r <br /> 20 January 2005 F <br /> • AGE-NC Project No 98-0540 <br />' Page 3 of 4 _ <br />' Analytical results of ground water samples are summarized in Table 2 Copies of the laboratory <br /> report(CTEL Project No CT214-0406262), quality assurance/quality control (QA/QC)reports and <br /> 'chain of custody forms are included in Appendix B <br /> 4,0. SUMMARY AND CONCLUSIONS <br /> Based upon data collected from the site, AGE concludes the following <br /> • During the June 2004 monitoring event,the ground water gradient was 0 004 ft/ft with a flow <br /> direction toward the east-southeast The flow direction was consistent with gradients and <br /> flow directions from previous monitoring events <br />' • TPH-g and BTEX compounds were only detected in the sample collected from MW-1 this <br /> quarter TPH-g and BTEX concentrations have not been detected in the samples collected <br />' from wells MW-2 and MW-3 for two consecutive quarters <br /> • The fuel additive 1,2-DCA was detected in the ground water samples from MW-1 and MW-3 , <br />� . at concentrations of 12 µg/1 and 70 µg/1, respectively <br /> • The 1,2-DCA concentrations detected In the samples collected from MW-1 and MW-3 <br /> exceeded the State of California's Maximum Contaminant Level (MCL) of 0 5 µg/1 <br /> rGround water in the area of wells MW-1 (former UST) and MW-3 (immediately down- <br /> gradient of former UST) is impacted by detectable concentrations of dissolved petroleum <br /> hydrocarbons and 1,2-DCA,the vertical and lateral extent of impacted ground water has not <br /> been fully delineated <br /> v <br /> 5.0. RECOMMENDATIONS <br /> 1 Based upon data collected from the site, AGE recommends <br /> • Continued ground water monitoring The third and fourth quarter 2004 monitoring events <br /> were conducted in September and December 2004, and <br /> • Continued work to assess the vertical and lateral impact of 1,2-DCA as per the Cone <br /> Penetrometer Testing and Monitoring Well Installation Work Plan, approved by the EHD <br /> by letter, dated 12 August 2004' The CPT was advanced on 13 October 2004 The on-site <br /> monitoring well installation is anticipated to be performed in the first quarter of 2005 AGE <br /> Is working on gaining permission from Caltrans to install the off-site monitoring well <br /> Advanced GeoEnviron mental,Inc <br />