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L. 16 September 1996 AGE-NC Project No. 95-0168 Page 4 of 5 the migration of contaminates (See Appendix D). 3.4. ANALYTICAL RESULTS OF SOIL SAMPLES A total of five soil samples were submitted to MAI for analysis based in field PID information. TPH- g was detected in sample B2-10 at a concentration of 1,100 ppm; xylenes were detected in the same sample at a concentration of 0.61 ppm.Petroleum hydrocarbons were not detected in any of the other F soil samples analyzed. Analytical results of the soil samples are summarized in Table 3. The laboratory report(McCampbell Analytical Lab ID 65698 to 65701 and 65711) and chain-of-custody `y are included in Appendix E. a 4.0. CONCLUSIONS AND RECOMMENDATIONS y 4.1. CONCLUSIONS !' Based upon results of the investigation of the former UST area, AGE has concluded the following: • Most of the hydrocarbon-impacted soil at the site associated with Tank No. 3 was removed t during excavation in 1995. • The lateral extent of the impacted soil left in place is limited to the eastern portion of the ( former UST excavation. • Field screening and laboratory analysis of soil samples collected from boring BI did not indicate the presence of petroleum hydrocarbons. Sample 132-10 contained 1,000 ppm TPH-g, but only 0.61 ppm xylenes from the BTE&X suite. The three deeper samples collected from boring B2 were.analyzed and did not contain detectable concentrations of hydrocarbons. two • The vertical extent of impacted soil left in place beneath the building at the site, is between depths of 5 and 15 feet bsg as demonstrated by the B2 samples. . An estimated 65 cubic yards of impacted soil remains under the southwestern edge of the building on-site (see Appendix F =Mass Balance Assumptions and Calculations). +� Ground water depth at the site is estimated to be between 55 and 60 feet bsg. • Based upon the small estimated volume.of petroleum hydrocarbons left in place and the soil .�; of low-permeability on the site, it is unlikely that the remaining impacted soil poses a significant threat to ground water. L.