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u. RIEDEL ENVIRONMENTAL SERVICES INC ' The 8 samples obtained during the second confirmatory sampling event were analyzed on site for TPHd by Argon. The results of the on-site analytical testing indicated that detectable concentrations of TPHd were not present in samples CD-02-102.5', CD-02-402.5', CD-02-502.5', CD-02-602.5', or CD-02-802.5'. However, samples CD-02-202.5', CD-02-302.5', and CD-02-703.0' contained 3300, 8200, and 16,000 ppm TPHd respectively. 1 Two additional samples were obtained from the areas of concern at depths of 6 and 7 feet below the top of the tank tie-downs. The two additional samples were analyzed on site by Argon. The ' results of the analysis indicated that sample CD-02-306.0' contained 820 ppm TPHd and sample CD-02-7@7.0' contained 21 ppm T'PHd. Copies of the analytical result sheets for all confirmatory samples obtained from the site are included in Appendix B. A summary of all soil ' sample analytical results are presented in Table 1. ' 5.3 Third Confirmatory Soil Sampling and Analysis On 17 November 1993, RES personnel arrived on site to retrieve four additional samples as ' requested by Ms. Meays. This additional sampling was conducted to help define the extent of the residual diesel in the soils at the bottom of the tank pit excavation. Samples CD-03-2, CD-03-3, CD-03-6, and CD-03-7 were obtained at a depth of 20 feet below grade utilizing a ' manually operated auger equipment and a slide hammer sampling device. .All sample locations were determined by Ms. Meays. The sample locations are shown on Figure 5. The 4 samples obtained during the third confirmatory sampling event were analyzed for TPHd by Argon. The results of the on-site analytical testing indicated that sample CD-03-2 contained 2800 ppm TPHd and CD-03-3 contained 110 ppm TPHd. Detectable concentrations of TPHd ' were not present in samples CD-03-6 or CD-03-7. A total of 4 additional samples from the areas of concern at the bottom of the excavation were ' obtained and analyzed in succession. Samples CD-04-2, CD-05-2, and CD-06-2 were obtained at depths of 23, 26, and 27.5 feet below grade beneath the location that sample CD-04-2 had been obtained. Sample CD-04-3 was obtained at a depth of 23 feet below grade beneath the ' location that sample CD-03-3 had been obtained. The additional samples were analyzed for TPHd by Argon. Sample CD-05-2 was also analyzed for BTEX. The results of the analysis indicated that sample CD-04-2 contained 1900 ppm TPHd. Sample CD-05-2 contained 170 ppm ' TPHD, but did not contain detectable concentration of BTEX. Samples CD-06-2 and CD-04-3 did not contain detectable concentrations of TPHd. 5.4 Fourth Confu-oratory Soil Sampling and Analysis On 18 November 1993, RES personnel arrived on site to conduct the fourth confirmatory sampling event, as required by Ms. Meays, in the area where additional over-excavation ' conducted by Aronson. Five samples were initially obtained at the bottom of the excavation at a depth of 20 feet below grade utilizing a manually operated auger and a slide hammer sampling device. The sample locations, which were determined by Ms. Meays, are shown on Figure 6. 4035-9315UU'%PB.9MK'I.RPr121MAP-% 4