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f Nos,., Mr.Michael Walton October 16,2003 Walton Engineering;Inc. TANK REMOVAL The former underground waste oil storage tank at the site was unearthed and removed by Walton Engineering, Inc., on September 11 and 12, 2003, respectively. Prior to the removal of the underground storage tank,the tank was rinsed and then evacuated by Ramos Environmental of West Sacramento,California. Approximately 100 pounds of dry ice was placed in the 550-gallon capacity, waste oil storage tank. The dry ice reduced the lower explosive limit(LEL) and displaced oxygen (02)to less than 1%in the tank, prior to removing the tank from the subsurface. Following the removal of the underground storage tank, the tank was inspected and found to be in good condition with no apparent perforations. The tank was hauled from the site and disposed of by Ecology Control Industries of Richmond,California. A representative from the local Fire Department was present to supervise the tank removal operation. FUEL DISPENSER REMOVAL Five fuel dispensers and the connecting underground product lines were dismantled and removed from the fueling station by Walton Engineering(FDI thru FD5 on Figure 2). The product line fiber- trench exposed by the fuel system renovation work contained mainly pea gravel as a backfill material. Soil encountered beneath the fuel dispensers consisted of a clayey sand, whereas soil encountered beneath the trench backfill material consisted of a stiff, medium brown, silty clay. An odor of fuel hydrocarbon was detected only beneath the product line trench near the northern ends of the fuel storage tanks (PL1 on Figure 2). Soil material observed beneath the former fuel dispensers and beneath the former product lines at locations PL2 thru PL4 did not exhibit evidence for fuel hydrocarbon contamination. SOIL SAMPLE COLLECTION WORK Following the removal of the underground waste oil storage tank, a soil sample was collected from beneath the fill end of the tank at approximately 7 feet below ground surface using a hand-operated AMS percussion core sampler containing a stainless steel sample sleeve. The sample was collected from the bucket of a backhoe immediately after removing the soil from the base of the tank excavation. Following the removal of the five fuel dispensers and associated underground product lines at the site, a soil sample was collected from beneath each former fuel dispenser and product line location using the core sampler. Immediately prior to each sample collection event, approximately I to 2 feet of soil material was removed from each sample location to expose fresh soil material at a depth of approximately 3 to 4 feet below ground surface. Each soil sample was collected by driving a clean sample sleeve through the freshly exposed soil surface using the percussion core sampler. Immediately after collecting each soil sample, the filled sample sleeve was sealed with plastic end caps,labeled with the project and sample identification numbers and date,and placed in iced storage. Additionally,a soil sample composite was collected from the soil stockpile generated during the tank removal work(SPla-d on Figure 2). The sample composite consisted of four discreet soil samples collected from the stockpile at random locations. Each discreet sample was collected after removing GRAYLAND ENVIRONhlENTAL Grayland 022-370.fdr 2