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• •hose 11 Environmental Site Assessment Heritage Square Page g laboratory analytical results, the soil in borings B-1, B-2, B-4, C-1, C-2, C-3, and C-4 have not been impacted by petroleum hydrocarbons. Additionally, laboratory analytical results for the groundwater sample collected from the abandoned well indicate that the groundwater from the completed zone at this location has not been impacted by petroleum hydrocarbons. 6.2.1 TKI Vicinity Sampling Concentrations of toluene, ethyl benzene, total xylenes, TPH-D, and TPH-MO were detected at or above the laboratory reporting limits in boring B-3 at 15.5 feet bgs. TPH-MO was also detected in the sample collected from boring B-3 at 15 feet bgs. PID readings ranged from 3.3 ppm to 42 ppm between 13 and 16.5 and 15.5 feet bgs and a slight odor and staining were noted for the same depths. Hydrocarbon constituents were not detected in any of the soil samples collected from the other borings advanced in the vicinity of TK1 (B -I, B-2, and B-4). The CAM 17 metals antimony, barium, cadmium, chromium, cobalt, copper, lead, nickel, vanadium, and zinc were detected at concentrations below the U.S. EPA Region IX Preliminary Remediation Goal (PRG) values for residential soils in the soil sample collected at 15.5 feet bgs in boring B-3. Arsenic was detected in this sample at a concentration above the PRG cancer endpoint value, but below the PRG noncancer endpoint value. TPH-MO was detected in the groundwater sample collected from boring B-3. MTBE was not detected in any soil or groundwater samples collected from the vicinity of TK 1. The highest contaminant concentrations in the samples collected during the Phase 11 ESA were found in the soils of boring B-3, east of the South end of TK1. 6.2.2 TK2 Vicinity Sampling Concentrations of TPH-D, TPH-MO, and TPH-K were detected at or above the laboratory reporting limits in a composite soil sample collected from boring B-5. Analytical results for the discrete samples comprising the composite sample indicate that TPH-D was detected at 1 1 feet bgs and TPH-MO was detected at 15.5 bgs. Total xylenes were detected in the boring B-8 composite sample. No hydrocarbon constituents were detected in the samples collected from borings B-6 and B-7, but PID readings ranged from 0 ppm to 3.1 ppm between four and 16 feet bgs in boring B-6 and from 2.6 ppm to 5.7 ppm between three and 10.5 feet bgs in boring B-7. The CAM 17 metals antimony, barium, cadmium, chromium, cobalt, copper, lead, nickel, vanadium, and zinc were detected at concentrations below the PRG values for residential soils in the soil sample collected at 15.5 feetbgs in boring B-5. Arsenic was detected in this sample at a concentration above the PRG cancer endpoint value, but below the PRGnoncancer endpoint value. Toluene, ethyl benzene, and total xylenes were detected in the groundwater sample collected from boring B-5. MTBE was not detected in any soil or groundwater samples collected from the vicinity of TK2. 6.2.3 Underground Piping and Abandoned Well Sampling No hydrocarbon constituents were detected in borings C-1 through C-4. Total lead was detected in soil samples collected from each of these borings at concentrations well below the400 mg/kg PRG value for lead in residential soils. MTBE was not detected in any of the soil samples analyzed for this constituent. No hydrocarbon constituents were detected in the grab sample collected from the abandoned well. 7.0 CONCLUSIONS The soil sample collected from boring B-3 at a depth of 15.5 feet bgs was contaminated by hydrocarbon constituents, but no deeper soil samples, including one collected a depth of 16 feet bgs, had detectable concentrations of these contaminants. These results indicate that soil contamination in the vicinity of TKl is restricted to depths shallower than 16 feet bgs. As the bottom of TKl is at 13 feet bgs, the contamination appears to be constrained to a narrow depth range. The tight clays that are characteristic of iJ CONDOR