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2.0 Summary and Conclusions <br />The results of the structural geologic evaluation for the Spec-Agg Quarry, which <br />included field observations, geologic mapping, and stereographic analysis of <br />structural geology data, indicate that the current quarry configuration is stable <br />under the existing conditions and current rock mass assumptions. The stability <br />of each of the slopes is enhanced by the absence of significant hydrostatic <br />pressures, by current mining procedures, and by the current reclamation <br />process. <br />The foliation set initially identified in the 2005 study is designated as F-3. To <br />date, not enough data have been collected to fully develop a hypothesis <br />regarding the location, extent and properties of the foliation; or to eliminate the <br />possibility that F-3 is basically a signature of the undulating nature of the existing <br />foliation set. The stereographic analysis indicates that the F-3 discontinuity plane <br />may only have minor influence on the south walls, and will not influence the <br />north, west or east walls. <br />Further analysis will continue to be conducted during subsequent investigations <br />to evaluate whether or not any of the foliation sets (F-1 through F-3) occur in the <br />same location simultaneously, or if the localized faulting has resulted in <br />`structural blocks" that have created regions in which the foliation planes occur <br />separately. These questions will continue to be addressed as more data are <br />collected. <br />Relative to each of the quarry walls, the north walls with an overall slope angle of <br />approximately 35° 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 <br />since the steepness of the wall slope was modified in 1999. Based on data <br />collected from boreholes in the 2003 geotechnical investigation, a number of <br />relatively shallow foliation surfaces will be encountered below the current main pit <br />elevation of 6,340 feet, and the north walls should be monitored closely as the <br />-2- <br />