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3.0 LABORATORY ANALYSIS Theroundwater samples were g p e e transported to Entech Analytical Laboratory (Entech), astate-certified laboratory, located in Santa Clara, California. The groundwater samples were analyzed as follows: �L Wells MW-1R MW-2 MW-4 and MW-5 were analyzed far the presence of TPH-g, BTEX, and the five fuel oxygenates(TAME, MTBE, DIPS, TBA,and ETRE) by EPA Method 8260B Copies of the laboratory analytical report and chain of custody record are provided in Appendix C. 4.0 SUMMARY OF RESULTS rV%4)6t J Based on groundwater elevation data for Fury, the groundwater flow direction in wells in both the upper and lower screened intervals was towards the southeast at gradients of approximately 0.002 feet per foot (ft/ft) and 0.03 ft/ft, respectively (Figures 3 and 4). The groundwater flow directions and gradients noted during this sampling event are consistent with historical trends. TPH-g concentration levels were less than the laboratory detection limit (25 gg/L) in wells MW-IR, MW-2; in wells MW-4 and MW-5 the reported concentration was 32 gg/L and 140 gg/L, respectively. BTEX compounds were sampled in MW-IR, MW-2, MW-4, MW-5; only toluene was reported above the laboratory detection limit in MW-4 (concentration of 11 gg/L). Oxygenates: The highest concentration of MtBE was reported in groundwater samples collected from upper zone well MW-5 at a concentration of 95 gg/L. MtBE was also reported in lower zone well MW-2 at a concentration of 17 gg/L. TBA was present in MW-5 at a concentration of 59 pg/L. Cumulative analytical results of groundwater samples collected from current and past sampling events are presented in Tables 1 and 2. Results are also represented graphically in Figures 5 and 6. Well construction details and status of screened intervals relative to current groundwater elevation are provided in Table 3. All wells have submerged screens. 5.0 CONCLUSIONS AND RECOMMENDATIONS During this sampling episode, ATC employed low flow sampling techniques. In general TPH-G, BTEX and fuel oxygenates have continued to decrease this quarter compared to previous quarters. Wells with increase in concentration this quarter are MW-5 and MW-4, with TPH-g concentrations of 140 gg/L and 32, respectively. MW-5 saw an increase in TBA concentrations from 26 gg/L last quarter to 59 gg/L in this last sampling event. MW-5 also saw an increase in MTBE concentrations from 78 gg/L last quarter to 95 gg/L this quarter. ATC recommends continuing with the next sampling event for third quarter in September 2006. el Quarterly GW Monitoring Report-2nd Qtr 2006 mvc Quik Stop No. 132 Quik Stop Markets,Mc. ATC Project No.75.62563.3206 July 5,2046 Paee 2 of 4