SITE INFORMATION AND CORRESPONDENCE

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4-0a-1997 d :,1GPf-} PROM AGE NC 209 9SG 0700 P- d 04 April 1997 AGE-NC-95-0112 Page 3 of 5 3.0. FINDINGS 3.1, STRATIGRAPHY Sandy silt was encountered from surface grade to approximately 16 feet bsg. Clayey 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 silt 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 probing. General site stratigraphy consists of silt 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. Silt 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). 3.2. LABORATORY ANALYSIS FOR PETROLEUM HYDROCARBONS Organic vapor was detected in probing P4 at concentrations as high as 116 part per million volume (ppmi) and in probing P5 at concentrations as high as 603 ppmv. Higher organic vapor measumments 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 probing P4 at depths of 15 and 20 feet at concentrations of 540 parts per million(ppm, reported as milligrams per kilogram) and 350 ppm, respectively. TPH-g was detected in probing P5 at concentrations as high as 4,300 ppm (40 feet). Ethylbenrene and xylenes were detected at concentration 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 in the remaining samples collected from probings P4 and P5. Analytical results of soil samples are summarized in Table 1. The laboratory report(AAI,Batch No. 97-0303-004) and chain-of-custody forms are included in Appendix B. 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. Samples P4-35 and P4-50 .were found to have porosities of 24.6%and 38.4°/x, respectively. The dry weight densities for samples P4-35 and P4-50 were calculated to be 126.2 pounds per cubic foot (pc f) and 102.7 pcf, respectively. The average density was therefore 114.5 pct'or 1.83 grants per cubic centimeter(g/cm�). 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