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i <br /> 11 <br /> . depth to groundwater gradually rose to about 65 feet below grade, and by June 1995 the groundwater <br /> level was about 60 feet below grade The groundwater gradient has been relatively consistent despite <br /> the fluctuations in elevation, with groundwater flow measured to be easterly under a gradient of 0 001- <br /> 0 003 On June 6, 1995 the hydraulic gradient was measured to be 0 003 to the east(Figure 4) <br /> The results of analytical soil testing indicates that soil samples from six well locations contained greater <br /> than 1,000 mg/kg TPH These well locations appear to be clustered in three separate areas (Figure <br /> 5) The first area is located along the west side of the property near the pump island and former <br /> western underground tank Soil samples from this area contained TPH concentrations of up to <br /> 4,100 mg/kg as found in sample TB4-10 The area is further defined by well locations MWS and <br /> TB6, which also had elevated contaminant levels in soil <br /> The second area is located near the center and to the east of the former tank cluster as defined by <br /> wells TB7, T1312, and MW2 Soil samples in this area contained up to 5,300 mg/kg TPH as <br /> found in sample T137-20 The third area is interpreted to be an isolated zone around boring/well <br /> TB3 This area had up to 5,700 mg/kg TPH as found at 30 feet below grade This location was <br /> the site of an unidentified subsurface fiberglass pipe that was discovered during site <br /> reconstruction The pipe was approximately 2-inches in diameter and appeared to run from the <br /> cashier's booth area north towards Harding Way There are no known uses for this pipe, but <br /> moderate hydrocarbon odors were noted in the surrounding soil <br /> Groundwater sampling results have shown that well MW 5, located near the western site <br /> boundary, consistently contains free floating product Each of the other wells has historically had <br /> high dissolved concentrations with up to 18,000 ug/l benzene detected in the groundwater The <br /> results of sampling from June 1995 show that only wells MW3R and TB 10 had less than 1,000 <br /> ug/l dissolved benzene (Figure 6) <br /> Page 3 <br /> i <br />