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DATA GAPS A sample point located west of Fernando's Place UST area, along the western property line would help delineate how and if the groundwater contamination migrates to Arc Pump at the T3-1 sample location CONCLUSIONS The soil samples obtained during the recent drilling activities at Are Pump show that the TPHg and Benzene in soil plumes are associated with the former UST area with little spreading Once the TPHg and Benzene contamination comes in contact with the first groundwater interval (28 to 32 feet below the surface), spreading occurred Both the Fernando's Place and Arc Pump soil plumes are separate but the Fernando's Place plume encroaches onto Arc Pump property at the 40 to 50 foot soil sample interval Below the 35 feet depth, with the exception of sample location T3-3 (44-44 5 fbs) sample TPHg is below laboratory lower detection limits of 1 mg/Kg with dust minor Benzene found in the soils at deeper depths, see Table 1 and Figures 4, 5, 6 and 7 The 620 mg/Kg TPHg found in sample T3-3-44-44 5 is felt to be from the releases that have occurred at Fernando's Place, not from Arc Pump And the deeper Benzene soil concentrations (deeper than 35 feet below the surface) are due to groundwater movement Figure 8 demonstrates the two separate TPHg plumes associated with Fernando's Place and Are Pump The much smaller TPHg in groundwater plume in the first water bearing zone (29 to 50 foot depth) is separated from the much larger Fernando's Place plume by sample points T3-2 and T3-3 Similar Benzene in groundwater plume is illustrated by Figure 9, where sample points T3-2 and T3-3 contain trace amounts of Benzene And in Figure 10, the MtBE in groundwater plume of the first water bearing zone, shows MtBE to be associated only with Arc Pump The second water bearing zone (78 to 92 foot depth) shows the TPHg and Benzene � groundwater plumes are commingled or more likely the southern migration of the Fernando's Place plumes MtBE was not detected in the second water bearing zone, which also supports that the second water bearing zone has been contaminated by Femando's Place releases not the Arc Pump release, see Table 2 and Figures 11, 12 and ` 13 J RECOMMENDATIONS With Benzene in soil (historically and currently) associated with the former ARC Pump UST area and the area of the former UST scheduled to be constructed as a shop complex that will be occupied, a work plan to over-excavate the former UST area to the top of groundwater (30 foot depth), backfill and compact the excavation to grade, profile and 9 ARC Pump, ASSESSMENT 2006