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Kennedy/Jenks Consultants <br /> The total lead concentrations in samples from the test pits in eastern OU-5 were less than the <br /> residential and industrial PRGs and CHHSLs. The arsenic concentrations ranged from <br /> 2.9 mg/kg to 5.5 mg/kg, exceeding PRGs and CHHSLs but consistent with the arsenic <br /> jconcentrations observed in OU-2 soils (presented in Table 6). <br /> 5.7.4 OU-5 — Organic Compounds <br /> The analytical results for organic compounds in soil samples collected from OU-5 are <br /> summarized in Table 12, with the applicable PRGs and CHHSLs as comparison values. <br /> 5.7.4.1 Soil Borings <br /> VOCs were not detected at concentrations exceeding analytical reporting limits in unsaturated <br /> soil samples analyzed using EPA Method 8260B. Only one of the numerous soil samples <br /> collected from OU-5 and analyzed for BTEX using EPA Method 8021 contained toluene and <br /> ethylbenzene at concentrations exceeding analytical reporting limits. Two of the soil samples <br /> contained xylenes at concentrations exceeding analytical reporting limits. Sample <br /> OU5-AO110-S-14-15/16 contained 3.2 mg/kg of xylenes and sample <br /> OU5-AO110-S-17-17.5/18 contained toluene, ethylbenzene, and xylenes at concentrations of <br /> 2.1 mg/kg, 6.8 mg/kg, and 7.3 mg/kg, respectively. These concentrations are less than the <br /> respective residential PRG and CHHSL values. Both of these samples were saturated samples <br /> collected from the aquifer material to analyze for fuel fingerprint. Hydrocarbon impact was <br /> visible in both samples and both had a hydrocarbon odor. <br /> Petroleum hydrocarbons were detected in several soil samples, except for TPHg which was not <br /> detected in any of the soil boring samples. Lower concentrations of TPHd (up to 43 mg/kg) were <br /> detected in several samples from soil borings OU5-AO19-S26, OU5-AO19-S27, and <br /> OU5-AO19-S28 in eastern OU-5. Higher concentrations of TPHd and TPHmo were detected in <br /> samples OU5-AO110-S-7-18.7/19.2 (this saturated sample had hydrocarbon odor and was <br /> collected from saturated soil to analyze for fuel fingerprint), OU5-AOI10-S-9-15/15.5, and <br /> OU5-AO110-S-10-15/15.5. TPHd and TPHmo were detected at concentrations of 1,200 mg/kg <br /> and 1,500 mg/kg, respectively, in sample OU5-AO110-S-17-15.5/16 (this sample was discolored <br /> and had hydrocarbon odor). <br /> In general, elevated TPH concentrations were found in samples collected from depths greater <br /> than 15 feet bgs in borings where visual and olfactory observations indicate that groundwater <br /> was impacted with hydrocarbon. The hydrocarbon in these samples may be due to contact with <br /> groundwater. <br /> 5.7.4.2 Trenches and Test Pits <br /> Samples from eastern OU-5 (OU5-AOI 11-TS-5-1 and the AOI 9 test pit samples) were analyzed <br /> for PAHs. PAHs were not detected at concentrations exceeding analytical reporting limits in any <br /> of the samples analyzed for PAHs, including the sample of the coal-like material in the PTP-9 <br /> area (sample OU5-AO19-TS-1-1). <br /> Five soil samples from AOI 11 in northern OU-5 (near the purple-colored material) were <br /> • analyzed for PAHs and organochlorine pesticides. The analytical results are summarized in <br /> DRAFT Phase I Remedial Investigation Report Page 34 <br /> Former Tracy Railyard, Tracy, California <br /> g:Gs-group\admin\job\05\0565777.18_uprr\09-reportstri rpt\text.doc <br />