Laserfiche WebLink
ff <br /> 5.2.3 Area 15 RAP Excavations <br /> Area 15 contained four RAP excavations at the locations shown on Figure 5. Table 1 identifies <br /> the COCs associated with each RAP excavation. RAP excavations 15132 and"1'5133'had <br /> confirmation samples that meet the RAOs after the initially proposed excavation was completed. <br /> A previously unknown UST was discovered near RAP excavations 15136 and 15139 and <br /> additional excavation in this vicinity caused the two RAP excavations to merge into a single <br /> s excavation (Figure 12). The UST excavation work began under the oversight of the DTSC; <br /> i <br /> however, due to the presence of the UST, the SJCEHD assumed oversight at the Area 15 UST <br /> excavation. The excavation continued under SJCEHD supervision until the SJCEHD was <br /> satisfied that the total petroleum hydrocarbons as gasoline (TPHg) and associated volatile <br /> j <br /> r organic compounds (VOCs) were adequately addressed, and the RAOs were met. Treadwell & <br /> i Rollo prepared a 28 March 2004 report to the SJCEHD which documented the UST removal and <br /> sampling activities that is included in Appendix C. (Treadwell & Rollo 2004d). As previously <br /> discussed, the SJCEHD has been and will continue to be the oversight agency for UST related <br /> l{ work at Areas 15, 16 and 21. <br /> I , <br /> Figure 11 shows the dimensions and confirmation sampling locations for RAP excavations <br /> 15B2, 15B3, and 15139. Figure 12 shows the dimensions and confirmation sampling locations <br /> for the Area 15 UST excavation. Confirmation sampling locations shown in gray on the figures <br /> indicate that these locations were removed during subsequent excavation. Table 5 presents the <br /> confirmation sample analytical results for,Area 15. The combined estimated minimum soil <br /> F volume for RAP excavations 15132 and 15133 presented in the RDIP was 12 cy, and the volume <br /> i <br /> estimated based on excavation dimensions after completion was 13 cy (Table 10). The <br /> combined estimated minimum soil volume for RAP excavations 15136 and 15139 presented in the <br /> RDIP was 43 cy, and the volume estimated based on the dimensions of the UST excavation after <br /> completion was 2,157 cubic yards (Table 10). The following section describes the confirmation <br /> sampling and analyses activities that were performed at the Area 15 UST excavation. <br /> `: 25971025.DGD 14 11 August 2005 <br />