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`. .i Upon entry into the County's Local Oversight Program and your approval of the remediation workplan, site cleanup was initiated on September 30, 1991. As soil was removed from the area near the south end of the former tank excavation, grab samples were screened with a photoionization detector to determine whether or not hydrocarbon contamination was indicated. At a depth of approximately 16.5 feet, a small amount of contamination was removed from the excavation and stockpiled separately from the soils which did not appear to be contaminated. Next, the area near the southern end of the former pump island was Lr overexcavated until field instrumentation no longer indicated the presence of hydrocarbon contamination. The final excavation extended to a depth of approximately 14.5 feet. Figure 1 - Site Plan in the enclosed consultant's report identifies the approximate locations of the remedial excavations. At your direction, soil samples were collected from the floor of each excavation, the west sidewall of the tank pit excavation, and the north side wall of the pump island excavation. TPH was indicated at 0.5 ppm in the sample collected from the bottom of the former tank excavation; however, it was not present at detectable concentrations in any of the other samples. Traces of toluene were indicated in ` all of the samples at concentrations less than recommended cleanup guidelines. Table 2 in the attached consultant's report summarizes the analytical results. Remediation activities generated approximately 50 cubic yards of slightly contaminated soil. All soil was stockpiled on plastic sheeting on a slightly elevated portion of the property and covered with additional sheeting to prevent runoff. Two composite samples collected from the stockpile indicated the r presence of 0.77 ppm and 33 ppm TPH. At this time, the soil is being profiled for acceptance into Forward Landfill. I will contact you when a removal date has been scheduled. ` With your approval, all soil which did not appear to be contaminated was used to backfill the excavations. Imported backfill was used to replace the volume of contaminated soil removed during remedial activities. With the exception of disposal of the soil stockpile, it is my understanding that no additional cleanup efforts will be required at this site. If this information ` satisfies your concerns regarding the subject property, please indicate your concurrence with our findings in your written reply. If you have any further questions regarding these matters, please feel free to phone me at (206) 286- 4495. If I am not available, Fred Proby may be able to answer any questions that you may have. Sincerely, z ` Anastasia E. Duarte Environmental Toxicologist Enclosure cc: Ms. Beth Thayer ` California Regional Water Quality Control Board aed/de 91/4026.Lt6 / k. !�