SITE INFORMATION AND CORRESPONDENCE_FILE 1

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Wendy L. Cohen -2- 15 March 1994 In 1991, Toxic Technology, Inc. (TTI) conducted a site assessment on the north parcel and submitted a Report of Findings in June 1991. TTI drilled seven ground water monitoring wells and collected soil and ground water samples. Soil samples at six to 14 feet bgs from MW-2, MW-3, MW-4, MW-6, and MW-7 contained TPH-D from 0.022 to 4,200 ppm. The water samples were all nondetect except MW-2 which contained 3, ppm TPH-D, 16 ppm TPH-motor oil, 1.1 ppb benzene and 2.0 ppb xylenes. MW-2 also contained free product approximately two inches thick. In August 1991, TTI submitted another report entitled Report of Findings, Phase II Environmental Site Assessment South Parcel. TTI drilled 11 soil borings and converted 10 of them to ground water monitoring wells (MW-8 and MW-11 through MW-19). Five of the eleven borings contained petroleum-contaminated soil ranging from 300 to 1,800 ppm TPH fuel mix (C7-C22). Of all the monitoring wells, only MW-13 contained hydrocarbons: 170 ppm TPH motor oil, 5.1 ppb benzene and 80 ppb total xylenes. This well also contained free product. In August 1991, TTI submitted a Remediation Workplan for the north parcel. I could not find this report in our files, but have requested a copy from TTI. Board staff approved this remediation plan with a few changes in a letter dated 5 November 1991 (copy attached). That letter requested a time schedule for implementation by 26 November 1991. In February 1992, TTI submitted a Remediation Workplan for the south parcel which TTI claimed was identical to the approved remediation plan for the north parcel. The plan proposed to excavate the contaminated soil and bioremediate it onsite. The report also stated that when the overlying petroleum-contaminated soils are removed, the immediate source of ground water contamination onsite would be eliminated. However, the report also points out that the overlying soils on the site are not the only source for ground water contamination. TTI stated the adjacent Southern Pacific pipeline easement had been considered the original source for the contamination and probably contained residual crude oil in greater concentrations than those found onsite. After removal and bioremediation of the soil, TTI stated new monitoring wells would be installed to monitor levels of ground water contamination. Excavation of soil began on the north parcel in the spring of 1992. Ten trenches were dug to depths of seven to 15 feet. Petroleum hydrocarbons as free product were in the soil and on the ground water in five trenches. In June 1992, TTI submitted a Report of Findings for additional trenching activities on the south parcel. The purpose of this trenching was to define more precisely the vertical and lateral exterit of the petroleum contamination and to determine volumes of soil for bioremediation. A total of 34 trenches were dug 10 feet long and from 10 to 20 feet deep. These trenches were all logged and visual contamination noted on the logs. The volume of contaminated soil in the south parcel was estimated at 10,000 cubic yards. In September 1992, TTI submitted a Report of Findings for additional trenching activities on the north and south parcels. Five trenches were placed along the Southern Pacific right-of-way, southwest of the Dividend Property, to assess the nature and extent of the hydrocarbon contamination in the right-of-way adjacent to the property. Soil samples were taken at each change of color within the trenches and a water sample was taken from Trench A. Soil samples from all five trenches contained TPH-D ranging from 110 to 320 ppm, ethylbenzene up to 44 ppb and total