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CRO Jeff Granberry ; September 26, 1995 ( 9447-8620) 3 _ 3.4 Soil Conditions Soils encountered during UST removal consisted of silt and clay from below the pavement base rock to approximately 14 5 fbg Fine sand and silty fine sand was encountered from 14 5 fbg to the total depth of the excavation Ground water was observed at approximately 1 i fbg within the excavation Soils exposed beneath the former product piping were dry silt and clay The maximum excavation depth of the product line trenches was approximately 8 fbg 3.5 Soil Disposition Approximately 2,090 yd' of soil were excavated from the former USTs, former piping and dispensers, and new UST locations between May 1 and June 16, 1995 The soil was previously characterized in place by Forward, Inc (Forward) by reviewing laboratory analyses of all soil samples collected during the initial investigations Forward authorized Shell to directly haul the excavated soil to Forward's landfill located in Manteca, California On occasion, it was necessary to stage stockpiled soil on and beneath plastic sheeting overnight to provide efficient delivery to the landfill Manley Trucking hauled the soil on five dates, May 4, 5, 11, 17, and June 16, 1995 Soil and UST disposal documents are included in Appendix H During excavation and loading activities, vapor emissions were monitored with a PID to . ensure that the health of the workers and general public was not being compromised The SJCPHS/EHD approved procedure was proposed in the April 17, 1995, "Emission Control Dunng Underground Storage Tank Removal Workplan " The workplan proposed action levels for contingency abatement measures Monitoring did not demonstrate the need to implement contingency measures Appendix B includes logs of the air monitoring 3. 6 Recoveiy Well InsUdlation On May 25, 1995, after the former UST excavation had been backfilled and properly compacted, a 6-inch-diameter recovery well RW-lA was installed to 30 fbg near the center of the former UST excavation (Figure 2) The drilling was performed by Gregg Drilling, under supervision of Fugro The well was constructed to accommodate both ground water and vapor extraction The screen interval is from approximately 10 to 30 fbg Standard well construction procedures, as presented in the SJCPHS/EHD Well Standards, were followed The drilling logs and well construction details are included in Attachment D The permit application for well installation is included in Appendix G 94478620 ARP 8