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10, a-680188 och lase Cl lSmac,.KoOrionB� value a p,fi 4.2.1. PCII Subsurface S i[ Sample Resorts A total of 35 .mil samples and Mrcc QA/QC duplicate soil samples were analyzed for PCBs using EPA Method 8082C. Three extmet duplicate samples were also analyzed for PCrl The PCH analytical results for subsurface soil samples collected from the boreholes in the Eastern GSA Debris Burial Trench area are presented in 3'able 4. Analytical reporting limits of 0.01 mg/kg and 0.0095 mg/kg were used for the EPA Method 8082C WE analysis for the regular samples analyzed by LIC Laboratories and the duplicate Samples analyzed by Curtis & Tompkins Iabortories, respectively. This differed from the Work Plan, which stipulated that an analytical laboratory reporting limit of O.ons mg/kg would he used for the EPA Method 80KC PCB analysis. Deserver, this reporting limit still meets the DOD stared in Table I Of tile Work Plan whereby Me reporting limit must be less Man the EPA's industrial soil Mrs of 0.22 mgBA for Atnclors 1221 and 1232, 0u7 mg/kg f r Aroclor IM2 and 1254, 0.94 mg/kg for Aroclor 1248, 0.99 mg,kg for Aroclor 1260, and 27 ing/kg for Aroclor 1016 (EPA, June 2015). While Mere are no MCL-bard Protection of Granted Water SSLs for specific aroclom as listed in Table 4 of the We& Plan, the repotting limits (0.0095 and 0.01 mg&g) am below the MCI,based Protection of Ground Water SSI. of 0.078 mg/kg for tell PCBs. PCBs were deecte i at concentrations above analytical RLa in four normal soil samples and two QC duplicate samples collected from five boreholes (H-EGSA-3028, -3029, -3029A, -3031, and -3034) (Figure 12). PCR concentrations ranged from 0.01 to 0.032 mgkg. In two of these samples (B-EGSA-3028 and -3034), the analytical laboratory repeated the analysis for the room x6act, and mnfrrmed the detections. In borehole B-EOSA-3031, a QA/QC duplicate sample at 4.5 B confirmed the directions of Aroclor 1254 and 1260, detected iu a normal sample collected at 5 fr. In borehole B-EGSA-3029, detections of Aroclor 1254 and 1260 in the duplicate sample at 4.5 n were not detected in the normal sample collected at 5 0. "the EMS detected included Auction 1016, 1254, and 1260. All soil samples Mat contained PCBs were collected near moll debris encountered in the boroholes. PCB concentrations were below EPA industrial and residential RSIs and the MCL-bused Profession of Ground Water SSL in all soil samples in all boreholes. The PCR detections in subsurface said samples and the EPA industrial and residential RSLs and Me MCI,based Protection of (.mund Water SSL am presented in 3'able ]. The complete set ofanalytical results for PCRs in subsurface soil samples are provided in Table 4. All PCB detections were vertically bounded by deeper soil samples that did not contain PCBs above the analytical reporting limit. Figures 13 and 14 show PCB sample resuhs on schematic crass-sec tons through the debris burial trench study area. With the sorption of B-EGSA-3029/-30a9A, all PCB deections were hemarrillly bounded by boreholos in which PCBs were not detected (Figure 12), The PCB concentrations detected in these boreholes, including B-EGSA-3029, were all well below Me soil RSI.s and MCL-based prmeGlon of ground water SSL. Only native material (no debris or VOQ) wasencountered during the 1991 excavation of Test Pit 6 locate east of e of borehole B-EGSA-3029 The mad to long and northeast of B-EGSA-3029 was constructed order use of the debris burial trenches was discontinued. These features (B-EGSA-3029, "I'esr Pit 6, mad) are shown on Figure 15.