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Ik � Soil and Groundwater Investigation Quik Stop No 121 Page 4 Subsurface soils were explored to depths ranging from 22 to 30 feet Continuous "direct push" cores were collected at each of the five sample locations by pushing a small diameter drive casing (3-inch outside diameter) from the surface to the total depth of each borehole Continuous soil cores were collected using a 3-foot long small diameter inner sample barrel lined with buterate tubing and 3-foot sections of A-rod After each 3-foot sampling run,the inner sample barrel containing three soil cores were removed from the hole The drive casing remained in the ground to prevent the borehole from collapsing and to prevent cross-contamination of subsequent soil samples In addition, the drive casing also prevents the entry of light nonaqueous phase liquid (LNAPL) into the borehole, which could contaminate groundwater in deeper zones Once the sample barrel was removed from the borehole, it was placed on a table and the 3-foot long buterate tubing containing a 3-foot core section was removed The soil inside the transparent tubing was then logged and selected 6-inch samples were then cut, capped with Teflon sheets and plastic caps, labeled, logged on a chain-of-custody form and stored in a chilled ice chest for preservation in the field and during transport to a state- certified laboratory CCI's soil sampling protocol is attached in Appendix A Grab groundwater samples were collected by installing 1-inch diameter PVC tubing into the open borehole Five to 10 feet of 0 010 slotted tubing was attached After allowing the water to equilibrate within the tubing, groundwater samples were collected using a '/z-inch diameter, stainless steel bailer equipped with a small ball valve Each groundwater sample was collected in appropriate laboratory-supplied bottles, labeled, logged on a chain-of-custody form and stored in a chilled ice chest for preservation in the field and during transport to a state-certified laboratory CCI's groundwater sampling protocol is attached as Appendix A During the investigation it was noted that groundwater was generally encountered at approximately 15 feet below the ground surface (bgs) At all five sample locations, groundwater flowed freely into each boring It should be noted that groundwater was not encountered until 20 feet at sample location GP-5 The groundwater at this location was under confined conditions and immediately rose to approximately 15 feet bgs Upon completion of the sampling at each GSS location, the holes were sealed with Portland cement using the l-inch PVC tubing as a tremmie pipe The cement was displaced to the surface, allowed to settle, topped-off, and the surface hole was then sealed with cold patch asphalt Subsurface Soil Conditions CCI explored subsurface soils to depths of 22 to 30 feet in the five GCCS locations In general, the upper 8 feet of soil encountered at the subject site consisted of brown to yellow-brown, silty sand The only exception was at GP-1,which was direct-pushed through the former tank excavation area and consisted of pea-gravel to a depth of 14 feet Below 9 feet, the subsurface soils became more granular, consisting of a yellow-brown, fine-to-coarse grain sand A sample (GP-2-15) was