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I <br /> C,eological Teclmc Inc Page 4 <br /> Groundwater Monitonng Report <br /> Project No 425 2 <br /> Apn] 18,2003 <br />' A chain of custody document, listing all samples collected and their intended analyses, <br /> accompanied the samples from field to the laboratory, thereby providing a means to track <br /> ' the movement and insure the integrity of the samples <br /> ' 1.3 Laboratory Analyses <br /> The groundwater samples collected on December 26, 2002, were delivered to Sherwood <br /> ' Labs (Department of Health Services Certification No 1400), of Hilmar, California, for <br /> analysis <br /> The samples were analyzed using the following methods <br /> • EPA method 8020/8015 — BTEX <br /> e EPA method 8020/8015(m) - TPH-Gasoline <br /> The detection limits for the above analyses are listed in Table 4 of Appendix A and the <br /> ' laboratory data are presented in Appendix B <br /> As required under AB2886, the laboratory data were submitted electronically to GeoTracker <br /> on April 9, 2003 - confirmation number 8944001972 <br /> ' 2.0 FINDINGS AND DISCUSSION <br /> The laboratory analytical data generated during the event indicate that gasoline constituents <br /> TPH-G & BTEX have been detected in monitoring wells MW-1, MW-2, MW-4 and MW-5 <br /> The results of the December 26, 2002 event are comparable with the results from previous <br /> ' monitoring events The following observations are made <br /> • The horizontal groundwater gradient is currently towards the north <br /> ' • Vertical groundwater gradients were positive or upward in the shallow/intermediate and <br /> intermediate/deep well pairs <br /> e TPH-G concentrations in MW-i continue to fluctuate within levels usually observed for <br /> the site A historical trend of increasing TPH-G concentrations may indicate lateral <br /> spreading of the plume to the west See Figure 6 for a graph of Benzene and TPH-G <br /> versus time (MW-1) and Figure 8 for the distribution of TPH-G <br /> ' • BTEX & TPH-G concentrations in MW-2 showed a decreasing trend since the June 20, <br /> 2001 monitonng event See Figure 7 for graph of Benzene and TPH-G versus time <br /> ' (MW-2) and Figure 8 for the distribution of TPH-G <br /> e Contaminant concentrations in wells MW-4 and MW-5 fluctuate seasonally but exhibit <br /> an overall increasing trend <br /> 1 <br />