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'%., ... 26 February 1996 AGE-NC Project No. 95-0152 Page 5 of 6 excavation;and B4,east wall of excavation). Benzene was not detected in any of the excavation soil samples. Analytical results of excavation soil samples are summarized on Table 2. The laboratory report (MAI Laboratory I.D. No.56683 though 56687) and chain-of-custody are included as Appendix B. 4.3. LABORATORY RESULTS OF PROBING SOIL SAMPLES Ten soil samples from all probings were submitted for analysis. Toluene was detected in samples P1- ` 15 and P1-40 at concentrations of 0.013 and 0.0072 ppm (parts per million), respectively. Ethyl benzene and xylenes were detected in sample P1-15 at concentrations of 0.0055 and 0.039 ppm, respectively. Other petroleum hydrocarbons were not detected in the soil samples analyzed. Analytical results of probe boring soil samples are summarized in Table 3. The laboratory report (CAL Laboratory No. 615-1S through 4S and 620-1S through -6S) and chain-of-custody forms are included as Appendix C. 4.4. LABORATORY RESULTS OF STOCKPILE SOIL SAMPLES One composite soil sample was collected from approximately 22 cubic yards of stockpiled soil. TPH- g, ethyl-benzene, and xylene were detected at 9.1, 0.0069, and 0.014 ppm, respectively. The laboratory report (CAL Laboratory No. 683-1S) and chain of custody forms are included as Appendix D. 5.0. CONCLUSIONS AND RECOMMENDATIONS 6. TPH-g was detected from the sidewalls of the excavation at concentrations between 770 and 3,500 ppm. Toluene, ethyle-benzene, and xylene constituents were detected from the side walls at .. concentrations up to 67, 75, and 360 ppm. Toluene, ethyl benzene, and xylenes were detected at concentrations slightly above the reporting limits in soil samples collected from soil probe boring P1 at depths of 15 feet 40 feet bsg. The estimated area of impacted soil is depicted on Figure 2; the estimated volume of impacted soil remaining at the site is approximately 210 cubic yards. A mass-volume calculation of the remaining impacted soil at the site yields approximately 16.96 gallons of petroleum hydrocarbons. An average concentration of 1,696 ppm was used to calculate the total volume of remaining hydrocarbons from 5 feet bsg to 11 feet bsg. An average concentration of 385 ppm was used to calculate the total volume of remaining hydrocarbons from 11 feet bsg to 15 feet bsg. An average concentration of 0.0016 ppm was used to calculate the total volume of