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'/� GEOMATRIX 3.1 GRAB GROUNDWATER AND SOIL SAMPLING On 21 March 1997, Geomatrix collected two additional soil samples and one grab groundwater sample near previously advanced boring SB-1 and the former location of test pit E to evaluate potential impacts to soil and groundwater from the pipe wrap material. A letter/work plan describing procedures associated with the collection of these additional data was submitted to PHS-EHD on 12 March 1997. Prior to submittal of the work plan and initiation of field work, Mr. Inf ima gave verbal approval to CPL of the proposed methods and field procedures (personal communication between CPL representative and PHS-EHD on 3 March 1997). Soil sampling services were provided by Precision Sampling Inc., of San Rafael, California. Borings were advanced using direct-push technology and were continuously sampled using a 3-foot core barrel lined with clear liners. Soil samples were retained for lithologic logging, field screening using a photoionization detector(PID), and laboratory analysis. A lithologic log of each boring was prepared in the field by a Geomatrix geologist using the Unified Soil Classification System (USCS) as described in ASTM D2488-90 "Standard Practice for Description and Identification of Soils (Visual-Manual Procedure)." Lithologic logs are included as Appendix A. As per the 12 March 1997 letter/work plan, one soil sample was to be collected from soil boring SB-2, located 332 feet east of the western property line and 3 feet west of previously advanced soil boring SB-1, at a depth corresponding to the most visibly impacted soil, or if no visibly impacted soil was deserved, at a depth of 5 feet bgs (1 foot below the former pipeline). A soil sample was not collected from SB-2 at a depth of 5 feet bgs due to poor sample recovery. A soil sample was collected at a depth of 10.5 feet bgs from boring SB-2 at the request of Mr. Infmna due to the presence of two small black inclusions at that interval. Boring SB-2 was then advanced to 22 feet bgs (approximately 3 feet below the water table) and a temporary f- inch PVC well with a 10-foot screen (0.02-inch slots) was installed and used to collect a grab groundwater sample using a stainless steel bailer. To collect a sample at 5 feet bgs as originally intended, a second soil boring, SB-3,was advanced 2 feet east of SB-2 and a soil sample was collected at a depth of 5.5 feet bgs. I:\WPDOCS\4097\ADDLINVB.DOC 4