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Irl Af Quik Stop Market No 121 CCI Project No 12118-2 Page 3 Monitoring wells MW-7, MW-1 I and MW-12 were all reported to be free of detectable petroleum hydrocarbons this quarter Monitoring wells MW-1 and MW-4 were reported to also contain detectable tert-Butyl alcohol (TBA) at 5 4 ug/L and 110 ug/L, respectively All three deep wells (B-aquifer), wells MW-6, MW-9 and MW-10, screened from 65 to 75 feet within the B-aquifer, were reported to be free of detectable TPHg and BTEX compounds Monitoring wells MW-6 and MW-9 were reported to have detectable MTBE, at 7 8 ug/L and 2 9 ug/L, respectively No other detectable compounds were reported in the three B-aquifer wells The results of the groundwater analysis are summarized in Table 2 The analytical reports from STL San Francisco and chain-of-custody documents are attached in Appendix B Discussion Based on the groundwater data obtained during the quarterly sample round, it appears the detected groundwater plume continues to remain in the vicinity of Quik Stop Market's fuel tanks, located on the southeast side of the site, near monitoring wells MW-3, MW-4 and RW-1 (Figures 2 and 3) Groundwater samples collected from perimeter wells MW-1, MW-2, MW-5, MW-7, MW-11 and MW-12 were reported to have relatively low concentrations or be free of detectable TPHg/BTEX and MTBE compounds Groundwater in the vicinity of monitoring wells MW-3 and RW-1 were reported to have the highest concentrations of MTBE at the subject site It appears MTBE remains in the upper shallow groundwater of the A-aquifer in the vicinity of the fuel tanks MTBE was detected in MW-4 (screened from 33 to 43 feet) at a concentration of 760 ug/L and in low concentrations in B-aquifer well MW-6 MTBE was also detected in very low concentrations in monitoring well MW-9 The other B-aquifer well, MW-10 was reported to be free of detectable petroleum compounds Groundwater measurements taken in ten of the shallow A-aquifer wells on July 2, 2002 indicated the depth-to-groundwater ranged from approximately 20 04 to 21 60 feet below the top of the well casings The water level in monitoring well MW-4 was measured at 20 68 feet below the top of the well casing The water table in the shallow A-aquifer has dropped approximately 3 5 feet during the last three months Groundwater contours in the A-aquifer monitoring wells indicate there is a slight gradient, ranging from 0 006 to 0 013 feet per foot, toward the northeast (Figure 4) A groundwater gradient map for the B-aquifer was created and indicates a gradient of 0 004 feet per foot to the south- southwest (Figure 5) CCI 1s preparing to install the KVA-C-Sparge System at the subject site The ten sparge wells . are currently scheduled to be installed during the week of July 22, 2002 and the installation of the KVA-C-Sparge System is anticipated to be completed by mid-August CCI will continue to