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• Mr Kyle Christie Project 0805-152 02 November 21, 1995 Page 2 the southeast corner of the site Although trace to low concentrations of gasoline hydrocarbons were detected below 70 feet bgs, the vertical extent of residual gasoline hydrocarbons in soil appeared to be limited to a depth between 50 and 70 feet bgs, dependent upon location, and from surface grade to approximately 70 feet bgs beneath the dispenser islands RESNA performed a vapor extraction test (VET) at the site on October 14, 1991, using vapor extraction wells VW-1, VW-2, VW-3, and VW-4 (RESNA, January 31, 1992, Report No 30041-2) The results of the test indicated that vapor extraction is a feasible means to remove residual gasoline hydrocarbons from the soil In December 1992, RESNA observed the drilling of one soil boring (B-26) and construction of a vapor extraction well Residual gasoline hydrocarbons were detected in soil samples collected from the soil boring (RESNA, March 18, 1993, Report No 30041-4) Groundwater was not encountered in the soil boring The lateral extent of residual gasoline hydrocarbons in soil has not been delineated southeast of the site In August 1993, RESNA researched the water supply well located at the site Results of .4 the investigation indicated the depth to first-encountered groundwater was not indicated on the Department of Water Resources (DWR) driller's log for the water-supply well (June 26, 1969), however, the log does indicate that the depth to groundwater after development was 100 feet bgs RESNA measured static groundwater after pumping the well for 0 25 hour Static groundwater was measured at approximately 58 51 feet below the access plug Based on current vapor extraction wells dulled to 115 feet bgs, RESNA concluded that first-encountered groundwater beneath the site is below 115 feet bgs, groundwater is under confined conditions, and the top of the first saturated unit, based on DWR driller's logs, is most likely 396 feet bgs or deeper In June 1995, a geologist from EMCON observed Woodward Drilling drill one soil boring and install one vapor extraction well (VW-18). In July 1995, a geologist from EMCON observed All Terrain Drilling drill two soil borings and install two vapor extraction wells (VW-19 and VW-20) Locations of the vapor extraction wells are shown on Figure 2 Groundwater was not encountered during drilling activities Results of laboratory analyses of soil samples collected from the borings indicated that TPHG concentrations ranged from below laboratory detection limits to 16 ppm, and benzene concentrations ranged form below laboratory detection hmits to 0 26 ppm ACTIVITIES PERFORMED DURING THE THIRD QUARTER No environmental work was conducted at the site during this quarter sACNNNPJft80W805i52a2C.S-9S1pas i