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\, <br />SMITH WILLIAMS CONSULTANTS, INC. <br />• <br />3.0 Site Subsurface Conditions <br />3.1 Previous Site Investigations <br />Site investigations for the Phase IV VLF and reported in Amendment No. 8, also covered areas <br />for the Phase 5 VLF. In general, these investigations consisted of site reconnaissance, test pit <br />excavation and drilling boreholes to assess subsurface conditions and extent of underground <br />mine workings adjacent to Squaw Mountain, existing electrical substation, and the crusher areas. <br />The site investigation information presented in Amendment No. 8 was considered sufficient to <br />support the design of the Phase 5 VLF. <br />As part of the Phase 5 VLF project, Smith Williams completed a detailed clay borrow source <br />program in the East Cresson area to delineate and qualify a source for the SLF. The geotechnical <br />investigation consisted of excavating test pits within the East Cresson mine area. The test pits <br />were excavated by Conley Construction using a Komatsu C200 track hoe, a Case 9040B <br />trackhoe, and a Case 590 backhoe. Smith Williams personnel supervised and logged each test <br />pit and collected soil samples for laboratory testing. <br />The pertinent geotechnical logs of the test pits and boreholes from the Phase IV VLF site <br />investigations, as applicable for the Phase 5 VLF, are presented in Appendix A. Test pit logs <br />from the SLF borrow source investigation are also presented in Appendix A. The results of the <br />geotechnical laboratory tests are presented in Appendix B. The following presents a summary of <br />the site geotechnical conditions. <br />3.2 Site Geotechnical Conditions <br />3.2.1 VLF Foundation <br />The Phase 5 VLF foundation materials will consist of the following: <br />Along the western edge of the Phase 5 PSSA, the foundation will consist of <br />compacted Phase IV ore. The Phase IV ore slope will be regraded to support <br />geomembrane liner placement. The regraded ore surface will be ripped, moisture <br />conditioned, and compacted to provide a firm surface for the PSSA. This is similar to <br />the construction of the Phase IV PSSA over the Phase III ore slope. <br />^ The eastern edge of the PSSA and the VLF will be founded on either compacted fill <br />over bedrock or compacted AGOSA overburden. In areas adjacent to Squaw <br />Mountain, the PSSA and VLF will be founded on compacted fill overlying <br />S:\PROJECTS\1125 CCBV PHASE 5 VLF\H2 - DESIGNWREQUA VLFIVLF PHASE 5 FINAL REPORT V2.DOC 1'~ <br />