ARCHIVED REPORTS_XR0012705 - Laserfiche WebLink

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a 4.0 SUMMARY OF FINDINGS AND CONCLUSIONS The findings and conclusions from this and past site investigative work, based on the results of laboratory analyses and field observations are summarized below: o The soil sampling data and field observations indicate that the excavation had effectively removed the hydrocarbon contaminated soil within the confines of the property. It is estimated that adsorbed-phase hydrocarbons remaining onsite, if any, are present only in concentrations of less than 10 ppm as TPH-G and/or TPH-D and are limited to the capillary fringe. It is also most likely that no detectable concentrations of STEX above laboratory detection limits are present in the soil onsite. o All the soil excavated from the site has been properly disposed of at designated offsite facilities ;A with approximately 3,.020 cubic yards hauled to the Liquid Waste Management, Inc. Class I1 landfill and approximately 3,060 cubic yards hauled to the Durham Road Class Ill landfill. o The predominant soil types encountered at the site are sandy silt underlain by silty clay, s o The shallow,,ground water flow direction beneath the site is toward the north/northwest, with an average gradient of 0.004 foot per foot. o The extent of adsorbed-phase hydrocarbons in the soil offsite, if present, has not been assessed. Residual absorbed-phase petroleum hydrocarbon i constituents in the soil offsite, if any, may be to the north and northwest of the property, in the lw general direction of ground water flow. o Analysis of the water samples collected during this investigation indicates no detectable concentrations .a of petroleum hydrocarbon constituents, organic lead or fecal, coliform, with the exception of the sample from AW-3. Detectable concentrations of TPH-D, TPH-G and HTEX were present in the sample from AW-3, '`x however, the concentrations of STEX do not exceed any of the corresponding state primary MCLS - for drinking . water. 10