ARCHIVED REPORTS_XR0011541 - Laserfiche WebLink

Home Browse Search

U-Haul#709-50 Preliminary Site Conceptual Model Slaes Environmental December 15,2006 Is 125' at a concentration of 0 005 mg/kg TPHg, BTEX, and Fuel Oxygenate compounds were not detected above laboratory reporting limits in soil sample DP7-150' Laboratory analytical results indicated concentrations of TPHg were detected in soil samples DP8-60 and DP8-80 ranging from 39 to 1 8 mg/kg, respectively Concentrations of BTEX were detected above laboratory reporting limits in soil samples DP840, DP8-60, DP8-80, DP8-125, and DP8-150 However, the only VOC analyte detected in the bottom soil sample in soil boring DP8 at 150 feet bgs was total xylenes at a concentration of 0 0088 mg/kg Concentrations of fuel oxygenates were not detected in any of the soil samples submitted to the lab from soil bonngs DP7 and DP8 The laboratory analytical results are summarized in Table 3 The laboratory analytical report with proper chain of custody documentation is included as Appendix I The soil sample analytical results as well as the estimated extent of hydrocarbon impacted soil is shown in the cross sections A-A' and B-B' presented in Figures 5 and 6, respectively 32.6 Findings Based on laboratory analytical results, the vertical extent of petroleum hydrocarbons in soil in the former UST area appears to be approximately 125 feet bgs since only total xylenes concentrations were detected dust above the method detection limit of 0 005 mg/kg at that depth and no constituents of concern were detected in soil sample DP7-150' above method detection limits Soil boring DP8 appears to be Iocated on the lateral edge of petroleum hydrocarbon impacted soil and defines the lateral extent of hydrocarbons in the western dispenser area as seen by the low level TPHg and BTEX concentrations observed in the soil samples collected from 60 and 80 feet bgs The vertical extent of hydrocarbons in the western dispenser area appears to be approximately 150 feet bgs based on the decreasing BTEX (specifically total xylenes) concentrations observed in the soil samples collected from soil boring DP8 Verbal approval to cease vertical characterization activities in the western dispenser area (DP-8) based on the mobile laboratory results was obtained in the field on March 8, 2006 from Mr Michael Infuma from the San Joaquin County Environmental Health Department Based on laboratory analytical results from all soil assessment activities conducted at the site to date, it appears that the vertical and lateral extent of hydrocarbon impacted soil at the U-Haul site has been completed successfully Page N