ARCHIVED REPORTS XR0012575 - Laserfiche WebLink

Home Browse Search

e w A s. I J II f:�rca�Fs�s 130�tyiwacP RIF z Considerable hydrocarbon odors and discolored(gray)soil were noted in sail removed from the excavation. Grab samples were periodically obtained from the excavator bucket and F i screened for hydrocarbons by sight, odor, and with the OVA No ground water was observed while excavating. Brown,loose,dry silt was the primary nativesail type found in the excavation. Clean soil, without visible petroleum hydrocarbon discoloration or odor, A+as found c,nsitently at a depth of approximate3y 25 feet in the deepened excavation. Wo soil samples MS 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_heeting, capped,labeled, and sealed with duct tape before being stored on ice in a cooler. The samples were submitted for laboratoryanalysis to confirm that the vertical extent of soil containing hydrocarbons had been reached.,Table I shows that sample TYN taken from the nchh end of the excavation(beneath previo�sample 5)contained only 63 : and 9.0 parts ped biMon (ppb)Toluene and Xylenes, respectively. TPHG and the other BTEX components were not detected, while TPHD was detected near the Iaboratory detection limit of 1 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 ewavation was also expanded in an east-west direction to assure the removal of soil eomaining hydrocarbons. Soil samples TYE and TYW 1 were taken from the base of the east and west walls, respectively,at a depth of.approximately. f 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 soil was defined. Table 2 shows that hydrocarbons were not detected in the soil samples except for 5.5 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--.bydrocarbons-has-been---------------------------- 4 e