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1 from the welts and equipment decontamination water was placed in Department of Transportation (DOT) ' approved I7H drums. The contents of the drums were transported by a licensed hauler for disposal at a licensed waste treatment site. The volume of groundwater removed from the wells and other measured sampling parameters are noted on the water sampling togs included in Appendix B. ' 3.0 LABORATORY ANALYSIS The groundwater samples were transported to STL Chromalab Analytical Labs, Inc., a state-certified laboratory, located in Pleasanton, California. The groundwater samples were analyzed for the presence of TPH-G, BTEX, the five fuel oxygenates, and 1,2 DCA and EDB in accordance with USEPA Method 8260B. Copies of the laboratory analytical report and chain of custody record are in Appendix C. 4.0 SUMMARY OF RESULTS A summary of the analytical results from current and past well sampling is presented in Table 1. Based on the groundwater-level data for August 30, 2002, ATC has interpreted the groundwater gradient and flow direction for the upper aquifer as shown on Figure 3. In the upper aquifer monitoring wells MW-5, MW-6, MW-7 and MW-10, the groundwater elevation decreased from the previous quarter an average of ' 0.875 feet, ranging from 0.81 feet in monitoring well MW-5 and MW-6 to 0.95 feet in monitoring well MW-10. The apparent groundwater flow direction in the upper aquifer was generally southeasterly at a gradient of approximately 0.003 (Figure 3). Based on the groundwater-level data for August 30, 2002 (Table 1), ATC has interpreted the groundwater gradient and flow direction for the lower aquifer as shown on Figure 4. In the lower aquifer monitoring wells MW-IR, MW-2, MW-3, MW-4 and MW-8, the groundwater level decreased from the ' previous quarter an average of 0.83 feet, ranging from 0.79 feet in monitoring wells MW-2 and MW-3 to 0.98 in MW-9. The apparent groundwater flow direction in the lower aquifer was generally southeasterly at a gradient of approximately 0.003 (Figure 4). ' Laboratory analysis of the water samples collected on August 30, 2002 indicates TPH-G, BTEX, and MTBE were not detected in groundwater samples collected from MW-31—MW-8 and MW-9 in the local ' lower aquifer, or MW-10 in the local upper aquifer.TPH-G and BTEX were not detected in any of the groundwater samples during this sampling event. MTBE was detected in groundwater samples collected from MW-IR (42 micrograms per liter (µg11)), MW-2 (4,000 µg11), and MW4 (7.9 µg11) in the lower ' aquifer; and MW-5 (2,200 µg11), MW-6 (0.61 µg/1) and MW-7 (1.1 µg11) in the upper aquifer. Fuel oxygenates other than MTBE (TBA, DIPS, ETBE, TAME), and 1,2-DCA and EDS were not detected in the groundwater samples collected from the ten wells sampled this quarter. The next quarterly ' groundwater sampling is scheduled for the fourth quarter of 2002. i 1 MATC Quarterly GW Monitoring Report-3rd Qtr 2002 Quik Stop 132 Quik Stop Markets, Inc. j,kPROJECMQVIK STOP MKTS%GS 13Z A pon.t2002N3rdO1r2002Rpt ATC Project No.75.62503.3203 November 11,2002 Page 2 of 3