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• 07 March 2000 AGE-NC Project No. 98-0432 ' Page 4 of 6 to contain petroleum hydrocarbons at depths of 5 bsg, lesser concentrations were encountered at 10 feet and l 5 feet bsg. Ground water was inferred to have a northerly flow direction and was found to be impacted locally by petroleum hydrocarbons and oxygenated fuel additives. 1 3.1. STRATIGRAPHY AND DEPTH TO GROUND WATER Tan silty sand and sand were encountered from a depth of approximately 5 feet to 15 feet bsg. ' Interbedded clay and sand strata were present.at depths between 15 feet and 25 feet�bsg. A Iaterally persistent clay was encountered at depths of 30 feet bsg in each well location. Ground water was encountered at a depth of 17 feet to 20 feet bsg. Soil borings are depicted in Appendix B. . 3.2. HYDROCARBON-IMPACTED SOIL A total of nine soil samples were analyzed for TPH-g, TPH-d, BTEX, MTBE in accordance with techniques prescribed by.EPA Methods 8015 Modified and 8260 Modified. ' compounds, TPH-d BTEX were not detected in any of the soil samples analyzed. ' The oxygenated fuel additive MTBE was detected in eight of the soil samples analyzed. Concentrations of MTBE detected in the soil samples ranged from 110 micrograms per ' kilogram(yg/Kg)to 2,580 µg/Kg. The highest detected MTBE concentration was from soil ' collected at 20 feet bsg; significant concentrations were also detected at depths of 25 feet and 30 feet bsg. ' Laboratory results of soil samples analyzed for petroleum hydrocarbons are summarized in Table 1. The laboratory reports (PET Laboratory ID PE6937-01 to -09), quality assurance and quality control (QA/QC) reports and chains-of-custody are included in Appendix E. 3.3. HYDROCARBON-IMPACTED GROUND WATER ' On 19 January2000 the ground water wells on the site were monitored and sampled. Each sample � � P P was analyzed for TPH-g, TPH-d and BTEX, with analysis for MTBE in accordance with techniques ' prescribed by EPA Methods 8015M and 8260 Modified. - • TPH-g, TPH-d and BTEX compounds were not detected in the ground water samples ' collected and analyzed from the site. • - MTBE was detected in three ground water samples analyzed. Concentrations.of MTBE ranged from 200 micrograms per liter (µg/1) to 9,800 µg/I in samples collected from monitoring wells MW-1, MW-2 and MW-3.