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low, "800 Mr Michael J. Infurna Jr. P.G., S.R.E.H.S. August 2, 2006 Page 7 HA-7-S-2' were both collected in the area east of the heavy equipment storage shed. TPHd and TPHmo were detected at concentrations of 22 and 67 mg/kg, respectively, in sample HA-6-S-6". In summary, the analytical data indicate only one location (HA-5) where significant residual TPHd and TPHmo (17,000 to 24,000 mg/kg TPHd and 13,000 to 15,000 mg/kg TPHmo) were encountered. Boring HA-5 was located approximately ten feet south of the heavy equipment storage shed and the well. The higher concentrations were in the shallow sample (HA-5-S-1.5'). The deep sample (HA-5-S-3.5') was collected just above the hard pan layer. The lateral extent of high TPHd and TPHmo concentrations is well constrained to the north by the ten samples from six boring locations. The remaining lateral and vertical extent of TPH impacts is not determined. As discussed above, PG&E requested that SECOR collect a sample from the well located on the south side of the heavy equipment storage shed (Figure 2). Although the well construction details for the well remain to be determined, the analytical results of the sample collected from the well do not suggest that the well has been impacted. The sample was analyzed for TPHg, TPHd, TPHmo, BTEX, and MTBE as well as a full 8260B scan of VOCs. With the exception of a single VOC, none of these analytes was detected at concentrations equal or greater than normal method reporting limits. The sole detection is 2,2-dichoropropane (at a concentration of 1.3 ug/L), which is near the 1.0 ug/L method reporting limit for this analyte. This analyte does not have an established state or federal maximum contaminant limit. CONCLUSIONS Based on the results presented in Table 1 and discussed above, SECOR presents the following conclusions. Residual TPHd (17,000 to 24,000 mg/kg) and TPHmo (13,000 to 15,000 mg/kg) are present in the soil samples collected at depths of 1.5 and 3.5 feet bgs from boring HA-5 located approximately ten feet south of the water well and the heavy equipment shed. The lateral extent of these impacts appears adequately constrained to north by the relatively low to non-detectable TPH concentrations reported for all ten samples collected from the six borings advanced at the heavy equipment storage shed and east of the shed. The remaining lateral and vertical extent of these impacts has not been determined. The analytical results on the water sample from the onsite well do not suggest that the well has been impacted by the residual TPH in the soil near the water well. The soil profile consists of fine-grained, relatively low permeability soils (silts and clays) and a competent hard pan that appears to be continuous beneath the site. This hard pan r I:\PG&E\2nd Pz II\report\Final PGE French Camp 2nd Phase 11.doc v