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Kennedy/Jenks Consultants <br /> Ile <br /> presented on Figure 6. The analytical results for TPH posted on Figure 6 are presented on <br /> Figure 7 through Figure 9 to assist in visual interpretation of the lateral extent of the TPH in <br /> groundwater. The distribution of TPHg in groundwater is presented on Figure 7, TPHd on Figure <br /> ' 8, and TPHmo on Figure 9. <br /> 5.4.1 OU-2 AOI 4 Soil Samples <br /> ' AOI 4, in the southeast portion of OU-2, is the area where three ponds were previously located. <br /> Soil samples were analyzed for Title 22 metals, TPHd, TPHmo, VOCs, and SVOCs. <br /> ' 5.4.1.1 OU-2 AOI 4 Soil Samples — Metals <br /> As shown in Table 6, 12 samples from three borings in AOI 4 were analyzed for total metals. <br /> Beryllium, molybdenum, and selenium were not detected at concentrations exceeding analytical <br /> reporting limits in any of the 12 samples. Silver and thallium were each detected in one sample <br /> at a concentration slightly above the analytical reporting limits. <br /> 1 One sample contained antimony at a concentration slightly above the residential CHHSL of <br /> 30 mg/kg. Cadmium was detected in five samples at concentrations that are equal to or exceed <br /> the residential CHHSL of 1.7 mg/kg, but do not exceed the PRGs or industrial/commercial <br /> CHHSL. <br /> ,• Lead was detected in four samples at concentrations exceeding the residential PRG and <br /> CHHSL of 150 mg/kg, but not the industrial PRG or CHHSL values. These samples include the <br /> two shallow samples from Boring OU2-A014-S2, and the two samples from Boring <br /> OU2-A014-S2. The lead concentrations in shallow soil samples from OU-2 samples are shown <br /> on Figure 5. <br /> Arsenic was detected in the 12 soil samples from AOI 4 at concentrations exceeding the PRG <br /> ' and CHHSL values. Most of the concentrations ranged between 4.2 mg/kg and 8.6 mg/kg, <br /> however one sample (OU2-A014-S-2-0/0.5) contained arsenic at a concentration of 16 mg/kg. <br /> The other 11 metals were not detected at concentrations exceeding CHHSL or PRG values. <br /> 5.4.1.2 OU-2 AOI 4 Soil Samples — Organic Compounds <br /> Concentrations of organic compounds detected in soil samples collected from AOI 4 are <br /> summarized in Table 7, which includes samples from the original borings and "replacement" <br /> Borings OU2-A014-S2-R and OU2-A014-S3-R. As discussed in Section 3.2.4, these two borings <br /> were drilled to collect samples for VOC analysis only. <br /> TPHd and TPHmo were detected at concentrations exceeding analytical reporting limits in soil <br /> ' samples collected from the three borings advanced in AOI 4. Hydrocarbon odor and <br /> discoloration were visible in soil in Boring OU2-A014-S1 from a depth of approximately 8 feet <br /> bgs to the total depth of 20 feet (see the boring log in Appendix A) but visible hydrocarbon <br /> impact was not observed in the other two borings. The TPH concentrations in Boring <br /> . OU2-A014-S1 increase with increasing depth, with a maximum TPHd concentration of <br /> 5,400 mg/kg and maximum TPHmo of 5,600 mg/kg found in sample OU2-A014-S-1-10/11 <br /> ' collected from a depth of 10 feet bgs. <br /> DRAFT Phase 1 Remedial Investigation Report Page 24 <br /> ' Former Tracy Railyard, Tracy, California <br /> g:Vs-group\adminlob105\0565777.18_upr6O9-reportsVirpNextdoc <br />