ARCHIVED REPORTS_XR0009695 - Laserfiche WebLink

Home Browse Search

and xylenes by EPA method 8020 for total petroleum hydrocarbons (TPH) by EPA method 8015 • modified, and for MTBE by EPA method 8260 A summary of historic analytical sampling results are provided in Table 1, and copies of the laboratory analytical reports for this reporting period are included in Appendix A Highest dissolved TPH,benzene, and MTBE concentrations recorded during the 4th quarter of 1998 were 23,000 micrograms per liter(ug/L) for MW-11, 5,400 ug/L for MW-11, and 49 ug/L for MW- 10,respectively All other wells exhibited either non-detectable or very low concentrations for these constituents TPH, Benzene, and MTBE distributions in groundwater during this reporting period are presented in Figures 3, 4 and 5, respectively Since the third quarter of 1997,Thrifty has sampled for the requested oxygenates di-isopropyl ether, ethanol, ethyl-tert butyl ethyl, methanol, tert-amyl methyl ether, tert-butanol, and methyl tert-butyl ether (MTBE) by method 8260 Analytical results are included in Appendix A Summary and Recommendations On November 19, 1998 Thrifty and San Joaquin County Public Health Department (SJCEHD) representatives had a meeting in the City of Stockton to discuss the most effective way for Thrifty to approach corrective action for this site The personal attending this meeting, and details of the meeting are addressed is in a letter which is included in Appendix B Thrifty is in the process of getting bids from contractors for the scope of work which was discussed in the meeting On November 24, 1998,quarterly groundwater monitoring was performed in all existing monitoring wells at Thrifty Oil Co 4172 Free petroleum hydrocarbons was not detected in any of the monitoring wells, but up to 5,400 ug/L dissolved benzene, and 49 ug/L MTBE were detected in monitoring wells MW-11, and MW-10, respectively Since December 23, 1998, Thrifty has received a bid from one contractor, and another contractor is in the process of submitting a bid The work is expected to begin in early January 1999 Once the work at this site has been completed, Thrifty will then have the site resurveyed Thrifty expects the work to be completed in four days All interpretations expressed in this report are based upon review of data collected by EMC Should you have any questions or require additional information, please contact either of the undersigned at (562) 921-3581 X376 Written By Reviewed By �D O (;aPo4n (CeA're ic sen Jay�Badiei, RG, RE I:' JALll.lAYBAf)I�I 4 Project Manager CA Registration#674 Q WO 674 4 0 Environmental Geologist Consulting Geologist