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Geological rechnlcs% Page 4 Tank Closure Testing Report Project No. 1218.2 +� August 3,2005 �.. • The soil sample collected at 14-foot bgs contained normal levels of lead (6.9mg/Kg) and low levels of diesel (20mg/Kg). The 14-foot bgs sample was non-detect above laboratory reporting limits for all other analyzed constituents. GP-3 • The 12-foot bgs soil sample contained normal levels of lead (1 lmg/Kg) and toluene �- (0.018mg/Kg), ethyl benzene (4.8mg/Kg), total xylenes (130mg/Kg), TPH-gasoline (3,100mg/Kg) and TEPH-diesel (1,800mg/Kg). The 12-foot bgs sample was non-detect above laboratory reporting limits for all other analyzed constituents. �- • The 14-foot bgs soil sample contained normal levels of lead (14mg/Kg) and ethyl benzene (0.064mg/Kg), total xylenes (2.8mg/Kg), TPH-gasoline (31mg/Kg) and TEPH- diesel (160mg/Kg). The 14-foot bgs sample was non-detect above laboratory reporting limits for all other analyzed constituents. 3.2 Geology and Field Observations The following section discusses the subjective field observations and geology documented during this investigation based on the interpretations of the field geologist. The boring logs `-' are attached in Appendix C. • The geologic soils of this site are dominated by silts • Small amounts of gravels in matrix were noted at 5 and 8 feet bgs V • Figure 3 shows the approximate extent of the plume • The area near GP-1 and GP-2 appear to have some thin fine grain sand units between 8 and 16 feet bgs. • The area near GP-3 is mostly alternating layers of silts and clays • OVM readings suggested little contamination in the area of GP-1 and GP-2 La • OVM readings suggested there was contamination in the area of GP-3 o OVM readings further suggest that the contamination is defined vertically in the area of GP-3. The OVM registered contamination at 12-feet bgs and the readings attenuated with depth, showing no organic vapors at 16-feet bgs. L" 4.0 CONCLUSIONS AND RECOMMENDATIONS This investigation was an effort to determine the possibility that a former UST located on the �- west side of the building may have leaked fuel and impacted the soil with petroleum hydrocarbons. The following conclusions have been drawn from the data generated from this site investigation work: Conclusions 1. There is a small amount of diesel and gasoline in the shallow subsurface at this site. The 'r contamination appears to be limited to a small area near the former dispenser above 15 feet bgs. V i.+