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C A M B R I A
<br />ANALYTICAL RESULTS
<br />Mr. Steven Shih
<br />June 20, 2005
<br />Table 1 summarizes soil analytical results, and Figures 2, 3, and 4 present the TPHg, benzene,
<br />and MTBE analytical data. The laboratory analytical reports are included in Attachment B. A
<br />summary of the data is presented below.
<br />Compliance Sampling: The six samples (TP -1-19 through TP -6-19) collected from the UST
<br />excavation did not contain any detectable TPHg, BTEX, or MTBE.
<br />Samples collected from beneath three of the dispensers (D-1-5, D-2-5, and D-3-5) contained 850,
<br />10,000, and 7,300 parts per million (ppm) TPHg, respectively. No benzene or MTBE was
<br />detected in these samples, although reporting limits were elevated. Sample D-4-5 did not contain
<br />any detectable TPHg, BTEX, or MTBE.
<br />Three samples collected from beneath product piping (P-1-5, P-2-5, and P-3-5) contained 220,
<br />2,300, and 3,800 ppm TPHg, respectively. No benzene or MTBE was detected in these samples,
<br />although reporting limits were elevated. Soil sample P-7-5 contained 0.011 ppm MTBE. The
<br />other samples (P-4-5 and P-6-5) collected beneath product piping did not contain detectable
<br />TPHg, benzene, or MTBE.
<br />The 12 samples collected from the pea gravel stockpiles (PG -1 through PG -12) did not contain
<br />any detectable TPHg, BTEX, or MTBE.
<br />Over -Excavation Sampling: Of the 17 samples collected from the excavation near the north and
<br />eastern dispensers, 10 (D-3-12, S-8-12, S-9-12, 5-10-12, S-11-12, S-12-7, S-13-7, 5-15-4,
<br />S-16-7, and S-17-11.5) contained TPHg at concentrations ranging from 1.4 to 11,000 ppm, 7
<br />(D-3-12, S-8-12, S-10-12, 5-11-12, S-15-4, 5-16-7, and S-17-11.5) contained benzene from
<br />0.020 to 1.0 ppm, and 3 (5-13-7, S-14-7, and S-15-4) contained MTBE from 0.013 to 0.042 ppm.
<br />Note that the soil from sample locations S-13-7 and S-15-4 was removed during the over -
<br />excavations activities (as indicated by shading in Table 1). Therefore, the only sample containing
<br />detectable MTBE that remains in place beneath the site is S-14-7 (0.013 ppm). The highest TPHg
<br />was detected in soil sample 5-8-12, located northwest of the eastern dispenser. Samples collected
<br />near the northern dispenser indicate that over -excavation was effective in removing TPHg,
<br />benzene, and MTBE from that area.
<br />Of the four samples collected in the vicinity of the western dispenser, one sample (S-1-7)
<br />contained 17 ppm TPHg and 0.081 ppm benzene. All four of these samples contained MTBE at
<br />concentrations ranging from 0.0057 to 0.11 ppm, with the highest concentration in sample S-1-7.
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