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Ej w <br /> P <br /> tank were exca-iated and removed from the site at the time the tank <br /> was removed. The fill material consisted of clayey soils similar to the <br /> surrounding clayey soils. <br /> Ground water at the site is unconfined and lies at a depth of <br /> approximately 6 feet below ground surface. Flow direction and <br /> gradient vary due to tidal water-level fluctuations in the nearby Deep <br /> Water Channel. However, the overallf depicts is toward <br /> ter <br /> the <br /> south (away from the Channel). Figure <br /> flow direction on March 16, 1990 at 0830 hours. <br /> Auah <br /> Samples collected during the various investigations were analyzed <br /> for some or all of the following constituents: <br /> • Total Petroleum Hydrocarbons (TPH) as gasoline and diesel; <br /> • Benzene, Toluene, Ethylbenzene, and Xylenes(BTE&X); <br /> • Ethylene Dibromide(EDB); <br /> • Total Lead and Organic Lead; and <br /> • Coliform Bacteria. <br /> UbonB. Laboratory analyses summarized in Table 3-1 <br /> indicate the presence of gasoline and associated compounds <br /> (benzene, toluene, ethylbenzene, and xylenes) in both soil and ground <br /> water. The highest concentrations are found in the vicinity of the <br /> former trnk, in a zone between approximately 6 and 11 feet below <br /> ground surface (see Figure 3-2). In this zone, concentrations of TPH <br /> (as gasoline), and BTE&X compounds have been detected in the range <br /> of several hundred parts per million. This zone of affected soils is <br /> below the ground water table and above the clay-sand contact. <br /> Apparently, soil below the groundwater table was not addressed <br /> during the tank removal. Outside of the high concentration zone, she <br /> total concentrations drop substantially; they are in the range of 10 <br /> parts per million or less. The estimated non-detect line is located as <br /> shown in Figures 3-1 and 3-2. <br /> Lg.�& Analyses were also performed for total and organic lead in soil <br /> and water samples. Samples collected during the removal f f so i soil by EHd construction showed total lead results of 2.6 pp <br /> and 6 pp g p <br /> m for water. Subsequent, samples were analyzed for organic <br /> ---- ---------------- ----------------- <br /> --- - -- lead: These later sample results-(for both.soil_and_water) were below <br /> detection limits (Table 3-1). The analytical findings suggest that e- — --- <br /> Y tank contained unleaded gasoline, and the total lead values reported <br /> represent background levels. <br /> 3-3 <br />