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1 <br /> barrel fitted with a 3 inch long screened expendable air sampling tip. (See Appendix A, <br /> Figure 29). The soil gas sampling tip will be advanced to the target depth,opened, and <br /> the sample tubing purged of ambient air with a vacuum pump. Before collection of <br /> samples,the sampling apparatus will equilibrate for 30 minutes. Methane and VOC <br /> ' samples will be collected in 6-liter Summa Canisters with gauges and will be checked for <br /> vacuum seal integrity before sample is collected.After samples are collected, Summa <br /> canisters will be checked for appropriate vacuum pressure and labeled with the <br /> t appropriate location and sample identification. Hydrogen Sulfide will be collected in <br /> Tedlar bags. In consultation with DTSC Project Managers and the boring logs located in <br /> Appendix C, all SVS samples will be collected at 5 and 10 feet bgs. If soil vapor <br /> ' sampling is unsuccessful then the boring will be advanced 2 more feet and re-sampled. <br /> Samples will be sent to a California Certified Laboratory under chain of custody <br /> procedures. The borings will be closed as per San Joaquin County Environmental Health <br /> ' Department directives and grouted to the surface with a cement slurry containing 3%-5% <br /> bentonite. <br /> ' Soil Vapor Sampling —Location <br /> Three SV S's will be collected in the area of former water wells which may have been <br /> vertical conduits to vapor movement. These three samples are: SVS-01-1 in the NW <br /> ' quarter of the block; SVS-18-2 in the middle of the block; and SVS-12-3 in the SE <br /> quarter of the block(See Figure 5).The other 3 borings are spread throughout the <br /> southern quadrant of the Site and are located underneath the proposed building footprints. <br /> SVS-01-1 is located between Condor's previous geotech boring B-1 and B-9 (see <br /> Appendix C: Boring Logs) on APN 149-085-01. Boring B-1 found lean clays from 2.5 <br /> ' feet to 11.5 feet bgs,silty sands from 15 feet to 16.5 feet bgs. Condor's boring B-9 found <br /> lean clays from surface to 5 feet bgs and silty sands from 5-12 feet bgs. <br /> ' SVS-18-2 is located on APN 149-085-18 equidistant between Condor borings B-8 and 13- <br /> 11. Boring B-8 encountered lean clays from 0-5 feet bgs and silty sand from 5-13.5 feet <br /> bgs. Boring B-11 encountered lean clay from 0-5 feet bgs, sand silt from 5-7 feet bgs <br /> ' and lean clays from 7-17 feet bgs. <br /> SVS-12-3 is located on APN 149-085-12 between Condor borings B-11 & 12. Boring <br /> ' B 12 was similar to boring B-11 in that it encountered lean clay from 0-5 feet, silty sand <br /> from 5-9 feet bgs and lean clay with silt from 9— 17 feet bgs. <br /> ' SVS-08-4 is located on APN 149-085-08 south of Condor's boring B11. This boring <br /> encountered lean clay from 0-19 feet bgs with a layer of sandy silt sandwiched at 5-7 feet <br /> ' bgs. <br /> SVS-18-5 is located between Condor borings B-6 and B-9 on APN 149-085-18. Boring <br /> B6 encountered sandy silt with gravel at 1-3 feet bgs,silty clay from 3-9 feet bgs, and <br /> silty sand from 9-15 feet bgs. Boring B9 encountered lean clay from 0-5 feet bgs, silty <br /> sand from 5-12 feet bgs and lean clay from 12-14 feet. <br /> ' PEA Workplan 19 <br /> Spans Elementary School <br /> January 18,2006 <br /> t <br />