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<br /> 3.0 LABORATORY ANALYSIS
<br /> ' The groundwater samples were transported to Severn Trent Laboratories, Inc. (STL), a state-certified
<br /> Iaboratory, located in Pleasanton, California. The groundwater samples were analyzed as follows:
<br /> ' ■ Well MW-IR was analyzed for the presence of TPH-G,MTBE,DIPE, TAME,ETBE, TBA;
<br /> ■ Wells MW-2, MW-5 and MW-8 were analyzed for the presence of TPH-G, BTEX, MTBE,
<br /> DIPE, TAME, TBA,ETBE;
<br /> ■ Wells MW-3 and MW-10 were analyzed for the presence of MTBE;
<br /> ■ Well MW-4 was analyzed for TPH-G,BTEX and MTBE;
<br /> ■ Well MW-6 and MW-9 were analyzed for BTEX and MTBE;and
<br /> ' ■ Well MW-7 was analyzed for MTBE, DIPE, TAME, ETBE, and TBA.
<br /> The selected analytical constituents were analyzed by US EPA Method 8260B. Copies of the laboratory
<br /> analytical report and chain of custody record are provided in Appendix C.
<br /> 4.0 SUMMARY OF RESULTS
<br /> ' Based on the groundwater-level data for June 17, 2004 (Table 1), the groundwater flow direction in both
<br /> the upper and lower aquifers was towards the southeast at gradients of approximately 0.003 feet per foot
<br /> ' (ft/ft) (Figure 3 and Figure 4). The average depth to water in upper aquifer wells MW-5, MW-6, MW-7 —
<br /> and MW-10 increased approximately 0.17 feet since March 2004, and the average depth to water in the
<br /> lower aquifer wells MW-1R, MW-2, MW-3, MW-4, MW-8 and MW-9 increased 0.11 feet during the
<br /> same time period. The groundwater flow directions and gradients noted during this sampling event are
<br /> lie consistent with historical trends.
<br /> Analytical results of groundwater samples collected from current and past sampling events are presented
<br /> in Tables I and 2. Analytical laboratory results of groundwater samples collected on June 17, 2004
<br /> indicate that TPH-G was present at concentrations of 800 micrograms per liter (µg/L) in groundwater
<br /> monitoring well MW-5 in the upper aquifer(the reported concentration was flagged by the laboratory for
<br /> not matching the TPH-G standard). TPH-G was also present in lower aquifer wells MW-IR, MW-2 and
<br /> MW-4 at concentrations of 57 gg/L, 160 gg/L and 110 gg/L, respectively. BTEX compounds were
<br /> ' reported below method detection limit concentrations in the sampled wells, except MW-4, where toluene
<br /> was reported at a concentration of 2.2 gg/L. MTBE was reported in groundwater samples collected from
<br /> upper aquifer wells MW-5 and MW-10 at concentrations of 740 gg/L and 1.7 µg/L,,respectively. MTBE
<br /> was also reported in lower aquifer wells MW-1R, MW-2, and MW-9 at concentrations ranging from
<br /> gg/L in MW-9 to 150 gg/L in MW-2.(a 196 YnTlh •,,4 w w y &)-o,S 14A%I Ll L 1 III J
<br /> ' Fuel oxygenates DIPE and ETBE,were not detected in the groundwater samples collected from wells
<br /> sampled this quarter. However, TBA was reported in groundwater samples collected from wells MW-2
<br /> (140 gg/L), and MW-5 (630 gg/L) and TAME was detected at concentration of 1.9 gg/L in well MW-2.
<br /> The next quarterly groundwater sampling is scheduled for September 2004.
<br /> Quarterly GW Monitoring Report-2" Qtr 2004
<br /> ulk Stop No, 13
<br /> (VATC Quik Stop Markets, Inc?
<br /> ATC Project No.75.62503.3205
<br /> August 12,2004
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