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' 6.0 Summary and Conclusions <br />The results of the structural geologic evaluation for the Spec-Agg Quarry, which includes <br />field observations, historic performance, geologic mapping and stereographic analysis of <br />structural geology data; indicate that the current quarry configuration appear to be stable <br />under the existing conditions and current rock mass assumptions. The stability of each of <br />j the slopes is enhanced by the absence of significant hydrostatic pressures, by current <br />mining procedures and by the current reclamation process being implemented by Lafarge <br />at the site. <br />' F-3, the additional foliation set was initially identified in the 2005 study. To date, not <br />enough data have been collected to fully develop a hypothesis regarding the location, <br />' extent and properties of the foliation; or to eliminate the possibility that F-3 is basically a <br />signature of the undulating nature of the existing foliation set. The stereographic analysis <br />indicates that the F-3 discontinuity plane may only have minor influence on the south walls <br />and will not influence the north, west or east walls. <br />Evaluations will be conducted during future investigations to evaluate whether or not any <br />t of the foliation sets (F-1 through F-3) are caused due to localized faulting that may have <br />resulted in "structural regions" that have created areas in which the varying orientation of <br />the foliation planes occur. These questions will continue to be addressed as more data <br />are collected. <br />With respect to the quarry walls, the north walls are currently being mined at a slope angle <br />of approximately 35° and are currently stable; and as stated in previous reports the slide <br />that occurred on the northeast wall has shown no signs of continued movement since the <br />steepness of the wall slope was modified in 1999. Based on data collected from <br />boreholes in the 2003 geotechnical investigation, a number of relatively shallow foliation <br />surfaces will be encountered below the current main pit elevation of 6,340 feet, starting at <br />an estimated depth of 6,325 feet and the north walls should be monitored closely as the <br />final 140 feet of excavation occurs. <br />-20- <br />Lachel & Associates <br />SCHHABFI FNGIHFFRIISG -Ofl VANY