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Kennedy/Jenks Consultants <br /> detected at concentrations exceeding analytical reporting limits in any of these samples. TPHd <br /> was detected in all three samples, at concentrations ranging from 67 pg/I to 130 pg/I. <br /> A total of 16 reconnaissance groundwater samples (including two duplicate samples) were <br /> collected from borings in and west of AOI 10 and analyzed for TPHg, TPHd, TPHmo, BTEX, <br /> and VOCs. <br /> As described above, hydrocarbon odor, discoloration, sheen, and/or hydrocarbon product was <br /> observed in the first encountered groundwater in Borings OU5-A0110-S4, OU5-A0110-S7, <br /> OU5-A0110-S8, OU5-A0110-S9, OU5-A0110-S10 (east of the railroad tracks), OU5-A0110-S14, <br /> and OU5-A0110-S17 (west of the railroad tracks). Visual or olfactory indications of hydrocarbon <br /> were not observed in the other borings advanced in AOI 10. <br /> TPHg was detected at concentrations exceeding analytical reporting limits in seven groundwater <br /> samples. The highest TPHg concentration (3,300 pg/1) was in sample OU5-A0110-GW-4-20, <br /> followed by 1,900 pg/1 in sample OU5-A0110-GW-14-20. Both of these samples were visibly <br /> impacted with hydrocarbons. The concentrations in the other five samples with detectable <br /> concentrations of TPHg ranged from 76 pg/l to 630 pg/I. <br /> TPHd was detected in most of the groundwater samples collected in and west of OU-5. The <br /> highest concentration of TPHd (720,000 pg/1) was in sample OU5-A0110-GW-4-20, and four <br /> other groundwater samples contained more than 10,000 pg/1 of TPHd. TPHd was not detected <br /> at concentrations exceeding analytical reporting limits in four samples from borings located on <br /> the southwest side of AOI 10. TPHd was not detected at concentrations exceeding analytical <br /> reporting limits in the two duplicate samples although TPHd was detected at concentrations <br /> slightly above the reporting limit in the primary samples. <br /> TPHmo was detected at concentrations exceeding analytical report limits in seven samples <br /> collected in OU-5. The TPHmo concentrations ranged from 520 pg/l to 600,000 pg/I, with the <br /> highest concentrations occurring in those samples with visible hydrocarbon impact. <br /> Benzene was detected in reconnaissance groundwater sample OU5-AOl10-GW-5-20 at a <br /> concentration just above the analytical reporting limit and xylenes were detected at a <br /> concentration equal to the analytics! reporting limit (5.0 pg/1) in another groundwater sample. <br /> None of the other 12 groundwater samples contained BTEX or MTBE at concentrations <br /> exceeding analytical reporting limits. <br /> Low concentrations of several VOCs were present in all but one of the groundwater samples. <br /> ' The VOCs detected at concentrations exceeding analytical reporting limits included several <br /> aromatic compounds and dichlorodifluoromethane (CFC12). Relatively higher concentrations of <br /> these VOCs were present in samples that also contained relatively higher concentrations of <br /> TPH. <br /> 5.7.6 Extent of TPH in Groundwater AOI 10 Area <br /> The analytical results for TPH posted on Figure 12 are presented on Figure 13 through <br /> • Figure 15 to assist in visual interpretation of the lateral extent of the TPH in groundwater. <br /> DRAFT Phase I Remedial Investigation Report Page 36 <br /> Former Tracy Railyard, Tracy, California <br /> g:1is-groupladminljob10510565777.18 uprr109-reportsld rptltextdoc <br />