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. concentrations of hydrocarbons were found in the samples collected from MW-6 (68 ppb gasoline, 4 8 ppb benzene, 1 1 ppb ethylbenzene, and 7 2 ppb xylenes), MW-8 (1 0 ppb benzene) and MW-9 (173 ppb gasoline, 3 3 ppb benzene, and 0 6 ppb xylenes) Hydrocarbons were not detected in the samples collected from MW-7 and MW-10 Low concentrations of MTBE were detected in the groundwater samples collected from MW-2 (9 2 ppb) and MW-4 (9 9 ppb), however, it was not detected in any of the other samples Table 2 in the attached report summarizes groundwater analytical data and laboratory reports are included as Appendix B The highest concentrations of hydrocarbons appear to remain onsite in the vicinity of the pump islands (MW- 1) and sidegradient of the former tank bed (MW-5) The groundwater plume does not appear to be migrating to any great extent When compared to the October 1998 sampling event, hydrocarbon concentrations remained relatively unchanged in each of the wells Additional monitoring data will be collected to further evaluate the extent of the dissolved hydrocarbon plume Additional Site Activities SECOR has been selected to design, install, operate, and maintain a soil vapor extraction/air sparging system at the subject site Costs for the scope of work to be completed have been pre-approved by the Underground Storage Tank Cleanup Fund At this time, SECOR is preparing a system design document which will be used for system installation Upon completion, the design document will be used to solicit subcontractor bids for system installation Time intends to seek pre-approval of subcontractor costs from the Underground Storage Tank Cleanup Fund prior to system installation If you have any questions regarding these matters, please do not hesitate to contact me at(206) 286-4495 I Sincerely, Time Oil Cc Anastasia E Duarte-Wilkinson Environmental Toxicologist cc Ms Elizabeth Thayer California Regional Water Quality Control Board I i 2