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Kennedy/Jenks Consultants <br /> SVOCs, although no VOC or SVOC analytes were detected at concentrations exceeding <br /> analytical reporting limits. <br /> Relatively elevated concentrations of lead were found in one soil sample from each of the four <br /> borings. In two of the borings, the elevated lead concentration was found in the deeper of the <br /> two soil samples. Elevated concentrations of TPH compounds in the samples corresponded <br /> with elevated concentrations of lead in the samples. <br /> Five reconnaissance groundwater samples were collected by Geocon in OU-4 in 2005. <br /> Analytical results indicate that groundwater in the southwest corner of OU-4, near the railroad <br /> track and the northwestern corner of OU-3, contains elevated concentrations of TPH. The other <br /> four samples either did not contain TPH at concentrations exceeding analytical reporting limits, <br /> or the detected TPH concentrations were relatively low (Geocon 2005). However, <br /> reconnaissance groundwater samples subsequently collected by Kennedy/Jenks in eastern <br /> OU-5, in the presumed downgradient direction, did not have elevated concentrations of TPH. <br /> 6.4.2 Conclusions <br /> Consistent with findings from the other OUs, analytical results from two of the soil borings <br /> indicate that concentrations of TPH and lead in soil decrease with increasing depth. However, <br /> data from the other two soil borings do not exhibit this trend. Lead concentrations in all eight <br /> samples were less than industrial CHHSL and PRG values. One surface soil sample contained <br /> a slightly elevated concentration of arsenic, but arsenic concentrations in the other seven <br /> samples were consistent with background concentrations of arsenic in soil at the Railyard. <br /> The elevated concentrations of lead and TPH were found in the same samples. However, <br /> neither the lead nor TPH concentrations appear to warrant additional soil characterization <br /> activities in OU-4. Based upon the analytical results from one soil sample, VOCs and SVOCs <br /> are not considered chemicals of interest in OU-4. <br /> Groundwater in the southwestern corner of OU-4, near the railroad track and Central Avenue, <br /> contains elevated concentrations of TPH. The available data, including analytical results from <br /> three reconnaissance groundwater samples subsequently collected from the eastern edge of <br /> OU-5, suggest that lateral extent of the TPH impact is limited. <br /> 6.5 Operable Unit 5 <br /> 6.5.1 Soil <br /> Subsurface features, including several former underground pipelines, are present in OU-5. <br /> Purple-colored material and slag ballast have also been observed in several locations in surface <br /> or near-surface soils. Coal-like material was observed in shallow soil in the eastern portion of <br /> OU-5. <br /> Soil samples were collected from 40 locations in OU-5 and analyzed for total lead and arsenic. <br /> Fourteen surface or near-surface samples contained lead at concentrations exceeding <br /> residential PRG and CHHSL values. Most of the samples with elevated lead concentrations <br /> were collected from surface or near-surface soil in the northern portion of OU-5, and may be <br /> DRAFT Phase I Remedial Investigation Report Page 43 <br /> Former Tracy Railyard, Tracy, California <br /> g:Gs-groupladminGo610510565777.18_uprr109-reportsl6 rpAtextdoc <br />