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S134 into a 2-inch diameter groundwater monitoring well (PT-MW1). Soil samples were collected at five foot intervals from each of the soil borings and field screened for volatile organic compounds using a photoionization detection (PID). Relatively low but positive PID readings were reportedly recorded by Applied GeoSystems on the log of soil boring for PT-S133 throughout most of the boring. The highest PID reading from PT-S133 was recorded at a depth of 20 feet bgs. Although the upper portion (0 to approximately 25 feet bgs) of soil boring PT-SB4 recorded background level PID readings,the highest recorded PID reading was recorded in boring PT-S134 at approximately the groundwater surface(40 feet bgs). None of the soil samples collected from PT-SB 1 to S134 were reportedly submitted for quantitative analysis to a state certified laboratory (Applied Geosystems, Inc., 1988). Soil boring PT-S134 was reportedly advanced to approximately 60 feet bgs and completed as monitoring well PT-MW 1. Prior to development of monitoring well PT-MW 1, Applied GeoSystems reportedly observed a petroleum sheen on water that was removed from the well. The sheen was later reportedly observed prior to pre-sampling purging of PT-MW 1. Upon attempting to sample PT-MW 1 Applied GeoSystems reportedly measured an immiscible product layer of approximately Y2 inch(0.05 foot)thickness. A sample of this immiscible layer was not submitted for analysis to a state certified analytical laboratory. In April 1991. Mr. Ganzer(Ganzer and Williams)reportedly retained Falcon Energy and Geological Audit Services, Inc. to further define the extent of groundwater impact by petroleum hydrocarbons at the site. In May 1991, Geological Audit Services (GAS) supervised the installation of two additional 4-inch diameter monitor wells (PT-MW2 and PT-MW3, Figure 6). Soil samples were reportedly collected at five foot intervals from each of the soil borings from depths ranging from 10 to 45 feet bgs. Field observations during the drilling of PT-MW2 reportedly indicated the potential presence of petroleum hydrocarbons from approximately 45 feet bgs to the total depth of 60 feet bgs. Field p Y pp Y g - potential presence of petroleum observations encountered while drilling PT MW3 indicated the po p hydrocarbons starting from a depth of approximately 20 feet to total depth of 60 feet bgs. The 30, 35, 40, and 45 foot soil samples from each of the wells were submitted for quantitative analysis eth lbenzene. and x of TPH-g and benzene,toluene, lene BTEX b y y ( ) Y USEPA Test Methods 8015M and 8020, respectively. Each of the soil samples reportedly contained detectable concentrations of the requested analytes. The 40 foot bgs soil sample from PT-MW2 had the highest concentration of petroleum hydrocarbon contaminated soil with a laboratory reported concentration of TPH-g (880 mg/kg) and BTEX (9.2, 45, 14 and 77 mg/kg, respectively) (Geological Audit Services, 1991). In June 1991, GAS surveyed the wells relative to a temporary benchmark and measured the depth to the groundwater surface. GAS reported measured product layers of 6.125 and 7.25 inches in monitoring wells PT-MW 1 and PT-MW2, respectively. GAS did not report observing Parmar\Site Assessment Workplan\02152018.wpd 4