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Site Charaeteiization and So.. -mediation Plan: 7500 West Eleventh Street, Tracv, i. Page 7 771-�fi ir+�j' ` .• Tank Pit No. 2 3 Three samples were recovered from the bottom of the excavation from which the old. tanks that had been discovered when piping was being removed from the site. The sampling locations, all of which were at a depth of approximately 9 ft., are shown on Figure b. As shown in Table 1, no detectable concentrations of gasoline were found in any of those samples, although very low concentrations of three or more of the BTEX compounds were found to all three. None of the samples contained detectable concentrations of MTBE Sample TP2-M, recovered from the approximate center of the pit botfbm, was affected by 1,500 mg/Kg of diesel. Sample TP2-S, from the south end of the pit bottom, contained 270 mg/Kg of diesel, but none was detected in Sample TP2-N from the north end of Tank Pit No. 2. -° Pipe Trenches Because of the maze of pipelines found in the area beneath the former pump i islands, the normal procedure by which a soil sample is recovered at intervals i along the length of the trench from which the pipe has been removed could not be practicably applied at this site. As discussed above, the complex array of =; piping found beneath the area of the former pump islands was removed, the area was over-excavated to remove soil affected by fuel hydrocarbons, and samples were recovered from the bottom the resulting pit. However, there were two pipe trenches that had been laid out in the more usual linear fashion and had connected separate areas of the site. Their locations are shown on Figure 3. The results of analyses of soil samples recovered at intervals along their lengths are presented in Table 1, and the sampling locations in Pipe Trench No- 1 and Pipe Trench No. 2 are shown on Figures 5 and 7, respectively. Pipe Trench No. 1 connected the former dispenser area with Tank Pit No 1, which had contained the four registered tanks in use at the time the Olympian r Service Station ceased operation. Two samples were taken from the bottom of that trench. One sample contained 1,200 mg/Kg of diesel and 530 mg/Kg of gasoline; the other contained 930 mg/Kg of diesel and 130 mg/Kg of gasoline. Each of the two samples contained very low concentrations of one or more of _._ the BTEX compounds, but no MTBE was detected in either of the samples recovered from Pipe Trench 1. # No detectable concentrations of gasoline or MTBE were found in any of the samples from Pipe Trench No. 2, although some of those samples contain very low concentrations of one or more of the BTEX compounds. Very low concentrations of diesel at 3. 1 mg/K and 1.0 mg/Kg were detected in two of the 5 sic