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r Depth to Groundwater(deep wells) 52 35 to 53 27 feet below top of well casing Groundwater Flow Direction/Gradient(deep wells) East/0 0006 ftlft DISCUSSION As discussed in the Site Conceptual Model (SCM), review of the subsurface geology and groundwater well elevation data indicate that although different transmissive (i a sandy) zones have been identified at various depths at this site, these zones appear to be hydraulically connected and likely form one continuous water-bearing zone Groundwater monitoring wells have been screened at three distinct intervals Shallow screened wells VEW-1, VEW-2, MW-2 through MW-7, and MW-15 were screened at various depth intervals between 40 and 70 feet below ground surface (bgs) Samples collected from these wells currently represent groundwater concentrations at first encountered groundwater Deeper screened wells intended to target sandy, more transmissive zones that may represent preferential pathways for petroleum hydrocarbon migration Mid-depth wells MW-16 and MW-18 are screened in sandy zones between 85 and 90 feet bgs Deep wells MW-8 through MW-11 and MW-17 are screened between 94 and 120 feet bgs, within a laterally continuous sandy unit first encountered at approximately 95 to 105 feet bgs Shallow Wells At the time of the fourth quarter 2004 monitoring event, groundwater was encountered in the shallow monitoring wells at depths ranging from 45 11 to 53 66 feet bgs Well MW-3 is obstructed Groundwater elevations had decreased between 0 01 and 0 49 feet in all shallow wells except VEW-1, which increased 7 65 feet since the previous monitoring event (August 23, 2004) Groundwater monitoring data were normalized to mean sea level (MSL) and used to prepare a groundwater elevation contour map (Figure 2) Well VEW-2 had only 0 26 feet of water column, and is interpreted to be dry The groundwater flow direction on November 19, 2004, was generally to the southeast at a gradient of 0 0006 ft/ft Since 1995, groundwater flow in the shallow wells has consistently been toward the east and southeast TPHG (1,500 pg/L) and benzene (46 µg/L) were reported in well VEW-1 TPHG was also reported in wells MW-2 (130 µg/L) and MW-15 (90 µg/L) 1,2-DCA was reported in wells MW-2 (150 µg1Q' MW-5 (1 7 gg/L), MW-6 (20 pg/L), and MW-15 (7 5 µg/L) MTBE, DIPE, ETBE, TAME, TBA, or EDB were not reported in any of the shallow wells These analytical results are generally consistent with historical data TPHG, benzene, and MTBE concentrations for samples collected and analyzed during the fourth quarter 2004 are summarized on Figure 3 Mid-Depth Wells At the time of the fourth quarter 2004 monitoring event, groundwater was encountered in the mid-depth monitoring wells at depths of 52 14 and 52 68 feet bgs Groundwater levels had decreased 3 22 feet in well MW-16 and increased 0 09 feet in well MWA 8 since the previous sampling event (August 23, 2004) Depth-to-water measurements have been summarized on Figure 4 Benzene (4 0 pg1L) was reported in well MW-18 TPHG, MTBE, DIPE, ETBE, TAME, TBA, 1,2-DCA, or EDB were not reported in any of the mid-depth wells TPHG, benzene, and MTBE concentrations for samples collected and analyzed during the fourth quarter 2004 are included on Figure 5 Deep Wells At the time of the fourth quarter 2004 monitoring event, groundwater was encountered in the deep monitoring wells at depths ranging from 52 35 to 53 27 feet bgs Groundwater elevations had decreased between 0 14 and 0 45 feet in wells MW-10 and MWA 7, and increased between 0 07 and 0 14 feet in wells MW-8, MW-9, and MW-11 since the previous monitoring event (August 23, 2004) Groundwater K\Apache Plastics\Quarterly reports120041Apache 4Q04 DOC STRA7U5