FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

Site Investigation and No Further Action Request Repo R&L Diesel Services, Project#051111 TM&W ff g. Describe the fate of any remaining monitoring and mediation wells. since 1934 No monitoring or remediation wells were installed. 9. Provide tabulated results of all groundwater elevations and depths to water. Based on boring B-5, the only boring which was advanced to groundwater, the depth to groundwater is approximately 54 feet. Groundwater depth is also tabulated on the boring log for B-5 in Appendix A. 10. Provide tabulated results of all sample analyses, including the sampling method and detection limits. fSoil sample analytical data, including sample dates, analyses, analysis methods and detection limits are provided in the included Tables 1 and 2, respectively. 11. Discuss concentration and mass changes over time, and current concentrations of fitcontaminants remaining in groundwater at the site. F-' The single groundwater sample secured from under the affected area on 04/20/09 was free of + hydrocarbon contamination at or above detection limits, except for tetrachloroethene (PCE), which was detected at 4.1 ug/l, less than the applicable California Primary Maximum Contaminant Level (PMCL). 12. Provide iso-concentration contour maps of contami lants of concern to define the lateral and F. vertical extent of contaminants remaining in soil an groundwater. The sketch included following section 3.3 of this report provides the location (vertical and lateral) of all soil samples, and the concentration of diesel and VOC remaining in soil, to define the lateral and vertical extent of impacts remaining in the s A. The impacted area is approximately ��- 8 to 10 ft. in diameter, and extends from the bottom of I he UST approximately 25 ft. down. r 13. Provide a summary of the remedial method(s) used to clean up the site: Due to the low concentrations detected in soil and grOL ndwater during subsurface investigation, no remedial activities were conducted at the site. 14. Provide a discussion of whether background is una tainable using best available remediation method(s). Remediation activities would likely be extremely disrup ive to normal business activities conducted in the transmission shop, and are not justifiE d in light of the relatively small area of impacted soil, entirely contained within the confines of he transmission shop, and the apparent lack of mobility of the constituents of concern. 15. Provide a discussion (and estimate) of contaminani mass remaining in soil and groundwater versus contaminant mass removed or destroyed by soil excavation or remedial action. 4 r x R: