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-M =- -91 a f4 i F L:i f:\prcj—\5130\tyi—mp Considerable hydrocarbon odors and discolored(gray)soil were noted in soil removed from the excavation. Grab samples were periodic—dlly obtained from the excavator bucket and screened for hydrocarbons by sight, odor, and with the OVA. No ground water was observed while excavating. Bromm,loose, dry silt was the primary native soil type found in the excavation. Clean soil, witbout visible petroleum hydrocarbon discoloration or odor, was found consistently at a depth of approximately 25 feet in the deepened excavation. Two soil samples(TYS and TYN on Figure 2)were collected in brass tubes driven into an excavator bucket of soil taken from the base of the excavation. The tube ends were covered with teflon sheeting, rapped, labeled, and sealed with duct tape before being stored on ice in a cooler. The samples were submitted for laboratory analysis to confirm that the vertical extent of soil containing hydrocarbons had been reached. Table 1 shows that sample TYN taken from the north end of the excavation(beneath previous sample 5)contained only 6.3 and 9.0 parts per billion (ppb) Toluene and Xylenes, respectively. TPHG and the other BTEX components were not detected, while TI'HD was detected near the laboratory detection Iimit of I ppm. No petroleum hydrocarbons were detected in sample TYS from the south end of the excavation beneath previous sample 2. In addition to deepening, the excavation was also expanded in an east-west direction to assure the removal of soil containing hydrocarbons. Soil samples TYE and TYW-1 were taken from the base of the east and west walls, respectively, at a depth of approximately 24 feet,as shown on Figure 2. The samples were obtained and handled as described above and submitted for laboratory analysis to verify that the lateral limit of hydrocarbons in the : e soil was defined. Table 2 shows that hydrocarbons were not detected in the soil samples except for 5.6 ppb Xylenes in TYE. The very low to nondetectable levels of hydrocarbons found in the samples taken after the October 1990 overexcavating indicate that the soil containing hydrocarbons has been t� 4 r