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' 04 April 1997 S AGE-NC-95-0112 Page 3 of 5 3 0. FINDINGS ' 3 1 STRATIGRAPHY Sandy salt was encountered from surface grade to approximately 16 feet bsg CIayey sand was encountered at 16 feet bsg, grading to coarse sand by 30 feet bsg and back to clayey sand at 40 feet bsg Clayey salt was encountered from 40 feet bsg to total depth of 55 feet bsg Boring logs are included in Appendix A Ground water was not encountered during probang General site stratigraphy consists of salt to silty sand from near surface grade to approximately 15 feet bsg However, a dense silt/clay layer is generally present from 12 to 15 feet bsg Sand is present from approximately 15 to 40 feet bsg Salt is generally encountered from 40 to 60 feet bsg Clay lenses were observed in several borings at depths near 45 feet bsg Sand is present from 60 feet bsg to total depth explored(75 feet bsg) ' 32 LABORATORY ANALYSTS FOR PETROLEUM HYDROCARBONS ' Organic vapor was detected an probing P4 at concentrations as high as 116 part per million volume (ppmv) and in probang P5 at concentrations as high as 603 ppmv Higher organic vapor measurements were concentrated between 15 and 20 feet bsg and again between 40 and 50 feet bsg TPH-g was detected in soil samples collected from probang P4 at depths of 15 and 20 feet at ' concentrations of 540 parts per million (ppm, reported as milligrams per kilogram) and 350 ppan, respectively TPH-g was detected in probang P5 at concentrations as high as 4,300 ppm (40 feet) Ethylbenzene and xylenes were detected at concentrations as high as 23 ppm in the samples collected from depths of 40 and 45 feet bsg in probing P5 BTE&X and MTBE were not detected an the - remainang samples collected from probangs P4 and P5 Analytical results of soil samples are summarized in Table 1 The laboratory report(AAL Batch No 97-0303-004) and chain-of-custody ' forms are included in Appendix B 3 3 SAMPLE PHYSICAL/GEOTECHNICAL PROPERTIES ANALYSES Samples P4-30 and P4-55 were found to have an organic content of 1 0% and 3 9%, respectively 'San=ples P4-35 and P4-50 were found to have porosities of 24 6% and 38 4%,respectively The dry weight densities for samples P4-35 and P4-50 were calculated to be 126 2 pounds per cubic foot ' (pcf) and 102 7 pcf, respectively The average density was therefore 114 5 pcf or 1 83 grams per cubic centimeter(g/cm3) Due to the dense nature of the soil at the site and the small diameter of the tubes used for sample collection, permeability analyses could not be performed on the samples