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CLEAR-WATER G R O U P I V C E,inrn+nmont rf Sin ice+ were free of detectable contaminant concentrations At this point, sorbed-phase contaminants appears to be adequately delineated Extent of Dissolved Hydrocarbons Analytical results from groundwater samples collected from the three new monitoring wells detected concentrations of TPHg and BTEX in the wells located directly downgradient (MW-5B, MW-7 and MW-8) relative to the former USTs Reported concentrations in MW-5B some 100 feet downgradient from the plume source are significantly higher than those detected in MW-1, immediately downgradient from the source Concentrations in cross-gradient well MW-6 are sirrular to those in MW-1 The upgradient extent of the plume is essentially defined at MW-2 Results of analyses of groundwater samples collected during this investigation indicate that the hydrocarbon plume associated with the site extends downgradient from the source approximately 250 feet to the southeast and has been thoroughly delineated laterally with MW-7 and MW-8, and vertically with a discrete water sample collected at 36 feet bgs in the former UST location (SB- 7@36') SB- 7@36') The presence of high concentrations of dissolved hydrocarbons down-gradient from the former USTs (MW-5B) with lower levels found closer to the former USTs (MW-1) suggests that the core of the plume has significantly move downgradient and/or the existing Jet Fuel Pipeline located under South Fresno Avenue has contributed to the subsurface contamination The Jet Fuel Pipeline is located approximately 12 feet off the east curb, under the road approximately 4 feet bgs Uafortunately the City of Stockton would not allow Clearwater to drill in the road to accurately assess this possible source Previously, onsite personnel observed significant hydrocarbon vapor release during subsurface road construction activities on South Fresno Avenue ZB 178C 7 3/31100