ARCHIVED REPORTS XR0000027 - Laserfiche WebLink

Home Browse Search

3 INVESTIGATION FINDINGS 1 Findings from PSC,s June 2004 subsurface site investigation are contained in the following sections These findings include descriptions of physical and chemical soil characteristics and groundwater conditions 3.1 Physical Characteristics of Vadose Zone The stratigraphic log obtained at the CPT-A location illustrates that much of ' the subsurface soil through the vadose zone is comprised of fine-grained silt or clay Soil samples collected from the borings were typically described by PSC's geologist as having a USCS classification of ML or CL These fine- grained soils were observed throughout the vadose zone to be predominately brown, relatively non-plastic and firm The CPT log displays primarily clayey ' or silty strata down to 100 feet with occasionally Interspersed stiff fine- grained materials that may be sandier in nature, however, PSC did not observe discrete sand lenses In any of the recent soil samples collected within the top 35 feet at the site The soil profile illustrated In the CPT-A log was similar to the profiles displayed in Iogs provided for borings CPT-1, CPT-2 and CPT-3, which were generated during the May 1999 site investigation Logs for the 1999 CPT borings are contained In Appendix A of this report 3.2 Chemical Characteristics of Vadose Zone ' As shown In Table 1, soil samples collected from the vadose zone following the removal of the UST's and prior to this most recent site investigation jtypically contained non-detectable petroleum concentrations TPH-G was only detected to two (30 and 35-feet samples from MW-2) of the seventeen samples collected from this interval Toluene was detected in Just qtr S T samples Benzene and xylene compounds were never measured at detectable? S levels This da suggests that much of the impacted soil may have been excavated during the 1987 removal of the former USTs As shown in Table 2, there were no detectable petroleum concentrations measured in any of the fifteen soil samples collected during the June 2004 investigation This data indicates that what residual petroleum hydrocarbon impact remained after the 1987 excavation was sufficiently addressed by the soil vapor extraction system that operated at the site and that the mass of impact in the vadose zone is negligable Vadose zone soil samples are illustrated in Figure 4 Laboratory analytical reports are contained In Appendix B 11 June 2004 Site Investigation Report The Earthgralns Company Facility 2651 South Airport Way-Stockton,California Prepared for SARA LEE BAKING GROUP Prepared by Philip Services Corp H VXV162400132U2I362EG4StocktonVF c 2004 fnvesugatnn Report doc August 9,2004