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24 May 2021 Project No. 14-3002 Page 17 of 23 PCBs were not detected above the laboratory reporting limit of 0.5 µg/l in the groundwater samples collected from AOC1 (Table 4). PCB EXTENTS The vertical extent of PCB contamination in AOC2 is defined and does not extend beyond 10 to 15 feet bsg depending on the location. The vertical extent is defined by samples collecting from several borings including B31, B43, B46, B47, B50, B59, B64, and B68. The lateral extent of PCB contamination in AOC2 is defined to the north, partially defined to the east, and undefined to the west and south of the Facility. It is likely that the lateral extent to the east does not extend beyond the property boundary due to the development of the adjacent property (17100 Murphy Parkway). Figures 10 through 15 and 17 through 21 depict PCB concentrations and illustrate the lateral and vertical extent of PCB contamination above the RSL of 0.97 mg/kg. 5.5.2. Dioxins and Lead Results and Extents A total of one soil, ten waste samples and four groundwater samples were analyzed for dioxins in AOC2. The samples were collected from borings B35, B36, B38, B40, B46, B48, B50 and B65. Dioxins were not detected above the laboratory reporting in the soil sample analyzed (B40-17). Dioxins were detected in seven of the nine waste samples at TEQ concentrations ranging from 0.238 pg/g (B35-14-soil/waste) to 96.6 pg/g (B46-10- waste). Dioxins were detected above the RSL of 22 pg/g in one waste sample collected from Waste Cell No. 2 and in two waste samples collected from Waste Cell No. 2A. Analytical results of dioxins are summarized in Table 2 and Figure 15 and depicted in cross-sectional view in Figures 17 and 21. Dioxins were detected in all four groundwater samples collected from AOC2 at concentrations ranging from 0.0126 pg/l to 2.41 pg/l, all well below the MCL of 30 pg/l (Table 3). Groundwater samples analyzed for dioxins were collected below the two waste cells in AOC2. A total of seven soil, seven waste samples and six groundwater samples were analyzed for lead in AOC2. The samples were collected from borings B31, B33, B34, B35, B36, B38, B40, B43, B46, B48, B50 and B65. Lead was detected in the soil samples at concentrations ranging from 1.9 mg/kg (B33-5) to 333 mg/kg (B40-13) and in the waste samples at concentrations ranging from 4.8 mg/kg (B35-10-waste) to 160 mg/kg (B48-7- waste). Lead concentrations were detected below the RSL of 800 pg/g. Analytical results of lead are summarized in Table 2.