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Mr.Aragon November 21, 2008 Page 8 of 9 subsequent confirmation sample (SPCC-B-2A-2), collected in the same location at a deeper depth after the additional excavation was complete, exhibited a B(a)P equivalent concentration of 0.008415 mg/kg. This sample along with all other confirmation samples showed no exceedances of the 0.9 mg/kg B(a)P equivalent screening criteria. Detected B(a)P equivalent concentrations in the remaining 16 confirmation samples ranged from 0.002974 mg/kg in Sample SPCC-B-2A-2DUP to 0.338029 mg/kg in Sample SPCC-W-11-2DUP. Analytical results for TPH showed no detections of TPH-g in any of the confirmation samples collected. In addition, TPH-d and TPH-mo concentrations were all below the preliminary screening criteria for the Site. As previously stated, Samples SPCC-B-2-1 and SPCC-B-3-1 were superseded (Figure 5) and replaced with Samples SPCC-B-2A-2 and SPCC-B-3A-2, respectively. Results from the subsequent samples showed no detections of TPH-g, TPH-d, and/or TPH-mo. The only remaining confirmation samples with detections of TPH are in Sample SPCC-W-11-2 and its duplicate (SPCC-W-11-2DUP). Concentrations of TPH detected in these two samples were 19 mg/kg and 5.3 mg/kg for TPH-d and 170 mg/kg and non-detect at the reporting limit for SPCC-W-11-2 and SPCC-W-11-2DUP, respectively. It should be noted that these detections are well below (an order of magnitude) the preliminary screening criteria. Title 22 Metals concentrations in the confirmation samples collected as part of the SPCC excavation operations showed detections for the following metals: antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, nickel, selenium, vanadium and zinc. The number of constituents and the concentrations detected in the confirmation samples were similar to background samples collected during the Remedial Investigation conducted at the Site. Typical metals constituents of concern at MGP sites include arsenic and lead. Results for arsenic in the 16 remaining confirmation samples collected during the SPCC excavation ranged from 2.74 mg/kg to 6.71 mg/kg. Lead results in the remaining confirmation samples ranged from 8.48 mg/kg to 25.3 mg/kg. The lowest concentrations for these constituents were observed in sample SPCC-W-7-2, whereas the highest concentrations for each of these constituents were observed in Sample SPCC-W-11-2DUP. Analytical results for PAHs, TPH, and Title 22 Metals in the confirmation samples are provided in Tables 7 through 9, respectively. The analytical laboratory reports are provided in Attachment A. Based on the comparison of the data provided in Tables 6 through 9 to the above screening criteria, there were no exceedances of the screening criteria. As such, the excavation area was backfilled and construction for the SPCC Containment Structure was initiated. 3.0 CONCLUSIONS AND RECOMMENDATIONS Based on the data from the 16 remaining confirmation samples, which represent conditions that currently exist at the Site in the vicinity of the SPCC Containment Structure, there are no exceedances of the DTSC approved preliminary screening criteria. Therefore, PG&E requests that DTSC provide a No Further Action (NFA) letter associated with the SPCC Containment Structure Area such that this area can be eliminated from any future environmental reporting (i.e. a Remedial Action Workplan). The construction of the SPCC Containment Structure was initiated on October 29, 2008 and is currently (at the time of the generation of this Report) ongoing. The SPCC Containment Structure construction work is being completed under the direction of PG&E and is being constructed under a building permit obtained by PG&E in concert with local, state, and federal building ordinances. It is anticipated that the SPCC Containment Structure will be completed within 30 working days.