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E3-1-10 had a CPAH detection of indeno(1,2,3-cd)pyrene (2,700 ug/kg), and a B(a)P equivalent
<br /> concentration of approximately 1.64 mg/kg was encountered at one foot bgs. The highest
<br /> naphthalene concentration was detected in Sample B 1-1-1 at 28,000 ug/kg. This detection is co-
<br /> located with the highest B(a)P equivalent concentration detected during the RI/SSI.
<br /> A total of 58 samples (including duplicate samples) had NPAH detections above laboratory
<br /> MDLs, some of which were co-located with the CPAHs. The highest NPAH concentration was
<br /> identified at 131-1-1: 55,000 ug/kg of pyrene. Maximum NPAH detections in soil included the
<br /> following: acenaphthene (1,700 ug/kg at E2-2-1), acenaphthylene (3,300 ug/kg at 131-1-1),
<br /> anthracene (2,900 ug/kg at B 1-1-1), benzo(g,h,i)perylene (14,000 ug/kg at B 1-1-1), fluoranthene
<br /> (50,000 ug/kg at B 1-1-1), fluorene (1,900 ug/kg at B 1-1-1),phenanthrene (41,000 ug/kg at B I-1-
<br /> 1), and pyrene (55,000 ug/kg at 131-1-1). In most cases, the highest detected NPAH
<br /> concentrations were co-located with the highest detected CPAH concentrations. The highest
<br /> NPAH result detected that is not co-located with CPAHs was observed in Sample Dl-1-8 at a
<br /> concentration of 46.0 ug/kg.
<br /> 4.1.2 Total Petroleum Hydrocarbons
<br /> A total of 83 soil samples were analyzed for TPH using EPA Method 8015M. Including
<br /> duplicate detections, there were nine gasoline detections, 22 diesel detections, and 18 motor oil
<br /> detections that exceed laboratory reporting limits. Detectable TPH-g concentrations ranged from
<br /> 0.610 mg/kg (A3-2-1) to 860 mg/kg (E3-1-10D). TPH-d concentrations ranged from 5.0 mg/kg
<br /> (D3-1-5) to 9,200 mg/kg (0-1-101)). The highest encountered TPH detection was encountered
<br /> at E3-1-101) (13,000 mg/kg of TPH-mo). Detectable TPH-mo concentrations ranged from 27.0
<br /> mg/kg (A3-2-3) to 13,000 mg/kg. TPH analytical data for soil is presented in Table 14.
<br /> 4.1.3 Title 22 Metals
<br /> A total of 83 soil samples were analyzed for Title 22 Metals using EPA Method 6010B.
<br /> Exceedances of laboratory reporting limits were identified among 13 of the 17 metals analyzed
<br /> in the suite including the following: arsenic, barium, beryllium, cadmium, chromium, cobalt,
<br /> copper, lead, mercury, nickel, selenium, vanadium, and zinc. Antimony, molybdenum, silver and
<br /> thallium all resulted in concentrations below laboratory reporting limits. Title 22 Metals
<br /> analytical data for soil is presented in Table 15.
<br /> On-site concentrations of arsenic generally do not appear elevated as only 7 of the 83 samples
<br /> exhibited values higher than 10 mg/kg, the highest being 12.6 mg/kg at A3-2-1. On-site
<br /> concentrations of lead did not appear to be elevated as well, with only 14 of the 83 samples
<br /> showing concentrations above 10 mg/kg. The highest lead concentration (41.3 mg/kg) was
<br /> encountered at E I-SG 1-2.
<br /> While many of the metals appear to be within "background" concentrations, there were four
<br /> isolated, elevated concentrations. BI-1-5 and DI-1-3 had barium concentrations higher than
<br /> general Site concentrations: 1,160 mg/kg and 647 mg/kg, respectively. A3-2-1 and E2-2-1 had
<br /> zinc concentrations of 183 mg/kg and 110 mg/kg, respectively, which were higher than all other
<br /> detections. Although these concentrations appear to be above background levels for the Site,
<br /> they are within ranges identified in California soils.
<br /> PARSONS 33 FINAL RI REPORT-FORMER TRACY MGP
<br /> APRIL 2010
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