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' 26 January 2007 AGE-NC Project No. 01-0839 Page 6 of 12 4.3. WELL COMPLETION ' Pilot boring MW5 was completed as ground water monitoring well MW-5 using 2-inch diameter, ' Schedule 40 PVC casing with 0.020-inch slotted screen installed from 60 feet to 80 feet bsg. The filter pack (No. 3 Lonestar sand) was installed from 58 feet to 60 feet bsg and a nominal 2-foot bentonite chip plug was installed above the filter pack and hydrated. The remaining annular space ' was filled to near the surface with a portland cement grout mix and a water-tight,traffic-rated well box was installed over the well. An as-built well diagram is depicted on the boring log in Appendix D. 5.0. CPT AND WELL INSTALLATION FINDINGS ' Soil stratigraphy was determined from field data collected during advancement of the CPT soil borings and the monitoring and vapor well pilot soil borings; hydrocarbon impact to ground water 1 and soil was quantified by laboratory analysis of ground water and soil samples. 5.1. STRATIGRAPHY The site stratigraphy appears to be dominated by fine-grained material(silty clay,clayey silt,and silt) from surface grade to the total depth of boring CPT-2(150 feet bsg). Silty sand, sandy silt,and sand were encountered in borings V W l,V W 6,and V W 3 beginning at 15 feet bsg and extending to 25 feet or 30 feet bsg; the sand was generally fine- to very fine-grained and poorly graded except for the clean sand encountered at 30 feet bsg in boring VWl, which was fine- to coarse-grained, well graded,and contained some gravel.Zones of sandy silt were identified in boring VW 1 at 50 feet and ' 60 feet bsg, in boring VW6 at 60 feet bsg, and in boring VW3 at 55 feet bsg. In boring MW5, approximately 250 feet east of the site,sandy silt and silty sand were identified at 45 feet and 50 feet bsg,respectively. From 55 feet bsg to 80 feet bsg,the total depth of the boring, light brown to dark ' brown, clean sand was encountered. The sand was fine- to coarse-grained with some gravel and generally saturated and well graded. This sand layer is identified on the CPT boring logs beginning at approximately 65 feet and extending to approximately 73 feet in boring CPT-I and 79 feet in ' boring CPT-2.An additional sandy layer is apparent in the CPT-2 boring log between approximately 91 feet and 97 feet bsg. ' The CPT computer-generated boring logs are included in Appendix C; monitoring and vapor well pilot soil boring logs are included in Appendix D. 1 Advanced GcoEnvironmental,Inc.