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16 February 1999 AGE-NC Project No 97-0290 ' Page 8 of 11 41 STRATIGRAPHY ' Silt tel 12 feet Silty sand and sandy silt were generally encountered from surface grade to approximately ' and from 15 to 25 feet bsg A hard clay to clayey silt layer was encountered from 12 to 15 feet bsg A stiffer silt layer was encountered in several borings at approximately 25 feet bsg Poorly graded sands were generally encountered between 30 and 60 feet bsg Clay and clayey silt were encountered ' to many borings from approximately 40 to 50 feet bsg Silt and sand lenses were observed throughout the site A hard silt to clay layer was encountered at a depth of approximately 60 feet bsg The boring logs are included as Appendix A Stratigraphic cross sections are presented in ' Figures 5 and 6 Lines of cross sections are shown on Figure 2 ' 42 ANALYTICAL RESULTS OF SOIL SAMPLES Organic vapor was detected in 9 of the 14 borings advanced at the site at concentrations as high as ' 10,037 ppm (P3 at 40 feet bsg) Organic vapor was not detected in soil samples collected from borings MW3, MW5, MW6, MW7 or B5 PID data is included on the boring logs (Appendix A) and ' is summarized on Table 3 TPH-g was detected at a concentration of 11.000 parts per million (ppm, reported as milligrams per ' kilogram), and BTEX compounds were detected at concentrations of 42 ppm, 420 ppm, 180 ppm and 840 ppm, respectively, in the sample collected from a depth of 40 feet in boring P3 TPH-g was detected in 15 of the 33 remaining soil samples analyzed at concentrations as high as 1,600 ppm (P3- 20) Benzene was detected in 9 of the 33 remaining samples analyzed at concentrations as high as 2 5 ppm (MW2-45) Petroleum hydrocarbons were not detected in soil samples analyzed from bonngs MWI, MW3, MW5 and B5 Oxygenates were not detected in the 13 samples analyzed by ' EPA Method 8260 Analytical results of soil samples are summarized on Tables I and 2 The laboratory reports(MAI Sample Nos 96889-96897, 99324-99330, 99540-99544, 01958-01970) and chain-of-custody forms are included in Appendix D The approximate extent of impacted soil is ' illustrated on Figures 4, 5 and 6 ' The permeability of samples B4-25, MWI-30 and MW3-55 was measured at 2 2 x 10', 3 5 x 10' and 3 3 x 10', respectively Porosity ranged from 32 26 percent to 41 16 percent Specific gravity ranged from 2 68 to 2 71 Percent organics ranged from 0 6 to 1 5 Sample B4-25 was a fine sandy ' silt, sample MWI-30 was a poorly-graded, medium-grained sand, sample MW3-55 was a silty fine sand Results of physical analyses are summarized on Table 4 The laboratory report in included ;n Appendix E I Advanced GeoEnvironmental,Inc