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t� • Mr Paul Supple Project 20805-140 003 April 30, 1998 Page 4 A Pumacle geologist visually inspected the USTs after removal The fiberglass UST was in good condition No evidence of fractures, corrosion, or holes was observed along welded seams or UST surfaces The waste-oil tank showed no evidence of holes, however, there was slight pitting on the bottom of the tank Each UST was marked with an identification number and loaded onto a flatbed truck for transport and disposal by Erickson, Inc , of Richmond, California Fill material removed from the UST excavation was designated as stockpile SP-1 and remained on site for use as backfill material for the UST excavation Tlus material was used to backfill the former UST cavity at depths of approximately 4 to 12 feet bgs Fill material below the USTs was stained in the northeast corner of the excavation Compliance soil samples collected from beneath the USTs (between 15 to 16 feet bgs) were mottled gray No staining of soil was observed in the waste oil UST excavation With the supervision of either the SJCPHS or Pinnacle personnel, product delivery line piping was dismantled and removed from the trenches after the UST removal activities • were completed by Henderson No staining of soil was observed beneath the fiberglass piping A second set of metal product delivery piping lines, located approximately 1/2 foot below the fiberglass piping lines, and slightly offset, was encountered and subsequently removed during excavation activities Soil beneath the second set of piping was mottled gray in the vicinity of the dispenser islands SOIL SAMPLING On February 10 and 13, 1998, Pinnacle collected soil samples from the waste oil UST excavation, gasoline UST excavation and piping trenches, and from beneath the former dispensers in accordance with the "Tri-Regional Board Staff Recommendations for Preliminary Evaluation and Investigation of Underground Tank Sites" (August 1992) and under the direction of the SJCPHS representative, Michael Kith Soil sample locations are shown on Figure 3 The SJCPHS representative observed the soil sampling activities As part of the excavation and sampling procedures, Henderson excavated a total of eight "potholes" to depths of 15 to 16 feet bgs ui the former gasoline UST complex Visual evidence of impact in the form of staining was observed to depths of approximately 16 feet bgs Faint to moderate petroleum hydrocarbon odors were present in the soil extending to the total depth excavated SAON NO +p80S48051400 3FS-94zusmer 1 �GOLctaC�Q