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y, R Working To Restore Nature (RESNA) in March 1992 (MW4) Monitoring well locations are shown on Figure 2 Soil samples collected from the capillary fringe zone in each well contained non-detectable concentrations of gasoline hydrocarbons (Table 1) Analyses of groundwater samples collected from the site monitoring wells indicate that groundwater contamination beneath the site was limited to a relatively small area in the immediate vicinity of the former tanks Groundwater flow has been consistently to the east On November 8 through 12, 1993, approximately 1,500 cubic yards of soil were excavated from the vicinity of the former underground fuel storage tanks in accordance with RESNA's May 1993 workplan No petroleum hydrocarbon analytes were detected in confirmation samples collected from the excavation pit, however, a discrete water sample collected from the pit was reported to contain 3,100 parts per billion (ppb) total petroleum hydrocarbons as gasoline (TPHg), 7 5 ppb benzene, 3 1 ppb toluene, and 190 ppb xylenes Analytical results for soil and groundwater samples are summarized on Tables 1 and 2, respectively The excavated soil was stockpiled on site The November 1993 field activities were discussed in detail in RESNA's Soil Excavation Report dated March 4, 1994 • FIELD ACTIVITIES Groundwater Disposal On April 28, 1994 approximately 54,076 gallons of groundwater was removed from the open excavation pit using vacuum pump equipped trucks Work was performed by Roto-Rooter Sewer Service and Star Sewer Service under the direct supervision of RESNA personnel The purged water was transported to the nearby Stockton Regional Wastewater Control Facility and discharged into the sanitary sewer system under an approved City of Stockton Department of Municipal Utilities discharge request Waste hauler manifest forms are included as Attachment 1. An attempt was made to locate the lower portion of well MW 1 which was damaged during excavation activities The well could not be located However, due to its shallow well depth (34 feet below grade) the remaining well casing is not expected to pose a threat as a potential conduit for vertical contaminant migration Sampling and Analytical Results Subsequent to purging activities, groundwater was allowed to flow into the pit and recover to its prepurge level A discrete groundwater sample was collected from the open pit using a disposable bailer The sample was placed immediately on ice and transported to Argon Mobile Labs (DHS Cert. #1873) and analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX), 1500591SUR-694 FNi. 2