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1 <br /> Page 7 <br /> Mr Michael Infurna Jr <br /> June 2, 1998 <br />' Findings <br /> As shown in the previous tables,there were no oxygenates detected at or above the <br />' laboratory method detection limit in any tested soil or groundwater sample <br /> Generally,the highest TPH-G concentrations in soil were measured in the shallow PH-2 <br /> and PH-1 samples that were collected from depths of 10 and 15 feet, respectively <br /> These sample concentrations are comparable to the excavation pit samples collected <br />' during the UST removal and are indicative of shallow TPH-G impact With the <br /> exception of the 35-foot sample from PH-1, TPH-G concentrations in the other tested <br /> samples ranged from non-detectable to 230 mg/kg Based on the investigation results, <br />' the vertical extent of TPH-G impact, higher than 100 mg/kg, is between 40 and 45 feet <br /> BTEX concentrations in soil are relatively low The higher TPH-G/BTEX concentration <br /> ratios measured in the tested samples are typical of soil impacted with an aged <br /> petroleum product With the exception of the 35-foot sample from PH-1, benzene <br /> concentrations in the other tested soil samples were measured at less than 1 mg/kg <br /> TPH-G and BTEX concentrations were detected in the groundwater samples collected <br /> from probeholes PH-1 and PH-2 These groundwater concentrations are inconsistent <br /> with the low to non-detectable petroleum concentrations contained in the soil samples <br /> collected from the depths of 40 to 50 feet The 40 and 45-foot depth soil samples from <br />' the two probeholes contained relatively low TPH-G and BTEX concentrations The 5 0- <br /> foot samples, collected at the interface of the vadose and saturated zones, contained <br /> non-detectable TPH-G and BTEX concentrations or concentrations dust above the <br /> laboratory detection limit Although an effort was made to prevent cross-contaminating <br /> the groundwater samples with the overlying impacted soil, the groundwater's hydraulic <br /> rise to a depth of 25 feet may have resulted in the measurable petroleum concentrations <br />' detected in the groundwater samples <br />' Closing <br /> This preliminary subsurface investigation and the product piping abandonment <br />' completes our authorized efforts at the project site on Eartligrams behalf If you have <br /> questions, or desire additional site information, please contact Ms Theresa Lanctot of <br /> Earthgrams at(314) 259-7073 Your cooperation in this matter is appreciated <br /> I <br /> r <br />