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v <br /> ! ATC <br /> A S S O C I A T E S I N C . <br /> A Flame Ionization Detection (FID) meter was used as a field-screening device for the detection <br /> of petroleum hydrocarbon vapors in cored samples. FID readings observed in the field during <br /> drilling activities did not exceed the background concentration of 5 ppm. Descriptions of soil <br /> types encountered and sample collection intervals are included on the boring logs contained in <br /> Attachment 2. <br /> Following soil sample collection, the borings were backfilled with neat cement grout to the <br /> ground surface. Mr. Jeff Wong of PHS/EHD was present on-site to witness drilling and grouting <br /> methods and procedures. <br /> Groundwater was not encountered during drilling activities. <br /> Soil Sample Analysis <br /> Selected soil samples were be placed on ice, and transported under chain-of-custody to Sequoia <br /> Analytical laboratory (FLAP No. 1210) for chemical analysis. The soil samples were analyzed for <br /> TPHd by EPA Method 8015 and BTEX and MTBE by EPA Method 8020. <br /> Soil Analytical Results - Former Diesel USTs <br /> The laboratory reported that none of the soil samples collected and analyzed from soil boring GPI <br /> contained aromatic petroleum hydrocarbon constituents (BTEX) above laboratory method <br /> detection limits. Of the samples analyzed from GP2, the only aromatic hydrocarbon detected was <br /> total xylenes (0.0058 ppm) at 20 feet bgs. This concentration is only marginally above the <br /> laboratory method detection limit of 0.005 ppm. <br /> GPI and GP2 contained concentrations of TPHd ranging from 1.00 to 2.57 ppm, however the <br /> chromatogram pattern indicated the presence of an unidentified hydrocarbon (C9-C24) in each of <br /> the samples. According to Mr. Kayvon Kimyai, Project Manager of Sequoia Analytical, these <br /> chromatograms do not match that of a fresh diesel standard and may or may not be naturally <br /> occurring organics in the soil. Mr. Kimyai stated that additional analyses would be required to <br /> provide further quantification. <br /> No MTBE was detected in the samples above the laboratory method detection limit of 0.0250 <br /> ppm. <br /> The analytical results for soil samples are summarized in Table 1. Laboratory data sheets and <br /> chain-of-custody documentation are included in Attachment 3. <br /> w:1172921mTmU\Supp)Invest.doc 4 <br />