Laserfiche WebLink
wa <br /> No TPH-G levels were detected in the soil samples <br /> from all four borings. only the soil sample from <br /> Boring P-1 had low levels of benzene, toluene, and <br /> xylenes. <br /> e MW-3 is the only well at the site with free-floating <br /> product, which was measured at approximately <br /> 0.o1 foot on July 7, 1990. MW-5, which is only <br /> 8 feet east of MW-3, has no free product, while the <br /> water level is 0.07 font higher than MW-3. Because <br /> of slow recharge in MW-3 compared to MW-2 and MW-5, <br /> and difference in water level and hydrocarbon <br /> concentrations, data from MW-3 was not considered in <br /> the development of the ground water elevation and <br /> isoconcentration maps. <br /> a The water sample from the offsite well, MPT-6, which <br /> is adjacent to an Exxon service station and <br /> crossgradient of the former Mobil site has the <br /> highest concentrations of TPH-G and benzene at <br /> 14,000 ppb and 590 ppb, respectively. <br /> e The sample from MW-8, located offsite and adjacent to <br /> a Chevron service station, and directly downgradient <br /> of Mw-6, has the next highest concentrations detected <br /> of TPH-G and benzene detected at 11,000 ppb and <br /> 27 ppb respectively. <br /> e No dissolved-phase TPH-G and BTEX constituents were <br /> "t detected in the sample from MW-7, which is <br /> a downgradient of the former Mobil site. <br /> J.4 a Based on the hydrogeologic conditions in the area and <br /> results of the field activities and laboratory <br /> analysis, there are potentially three hydrocarbon <br /> contaminant plumes in the vicinity of the site that <br /> have comingled: one onsite on the northeast corner of <br /> '~^ the former Mobil property; one adjacent to the Exxon <br /> property; and one adjacent to the Chevron property. <br /> The lateral extent of benzene concentrations in the <br /> .. comingled plume can be defined, however, the extent <br /> of TPH-G in the ground water cannot be adequately <br /> defined. <br /> a Characterization of each contaminant plume is beyond <br /> the scope of this investigation, however, other <br /> potentially responsible parties may have to conduct <br /> -- similar investigative work in cooperation with Mobil <br /> oil. A coordinated effort among the involved parties <br /> may be necessary. <br />