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monitoring plan should be developed and implemented so potential slope instabilities can be <br /> detected and addressed at an early, non-critical time in mine development. <br /> 6.1.2.1 Visual Inspection Monitoring <br /> GEI believes continuous monitoring and examination of active and reclaimed areas within <br /> the South Quarry will be necessary through the life of the quarry. On a monthly basis, the <br /> South Quarry should be monitored and inspected. At a minimum, the following warning <br /> signs of slope instability (global and local) should be looked for noted and addressed <br /> • Tension Cracks—Cracks on the tops of slopes and/or benches are signs of highwall <br /> instability. <br /> • Scarp, bulges, or creep— Scarps are areas where material has vertically moved <br /> downslope. Scarps can be several inches to many feet, occur relatively fast, and <br /> would have visible "offset". Bulges and Creeps are areas where material has moves <br /> downslope slowly and can be evident in bent vegetation or"incorrectly" oriented <br /> trees. These warning signs are likely to be present in reclaimed slopes and/or areas <br /> not undergoing active mining, such as areas outside the mine footprint, either beyond <br /> the permitted mine limit or in future expansion areas. <br /> • Abnormal Water Flows— Excessive flowing groundwater is typically not present <br /> within highwalls exposed within the South Quarry. The presence of flowing water <br /> out of final or active highwalls, reclaimed slopes, and/or areas not undergoing active <br /> mining would indicate a change in subsurface conditions that could lead to slope <br /> instability. <br /> • Abnormal rockfall at toe of slopes and or highwalls — Rockfall is a typical feature <br /> within the South Quarry. When monitoring for"abnormal" rockfall, rubble in areas <br /> where rockfall is typically not present, an increase in volume, and/or a distinct change <br /> in rubble dimensions could indicate slope instability and/or movement. <br /> 6.1.2.2 Survey Monitoring <br /> GEI also recommends that slope monitoring within the South Quarry utilizing electronic <br /> distance measurement (EDM) techniques should be conducted in concert with monitoring for <br /> warning signs discussed in section 6.1.2.1 above. EDM is a common and effective method <br /> for monitoring slope movement within rock quarries. <br /> The Al surveyor should set monitoring control points (prisms) at critical locations within the <br /> South Quarry. The control points should be permanent and located in areas where ongoing <br /> mining activities will not impact them, yet be in locations central enough to capture any <br /> potential slope movement. A control point installation plan should be developed in <br /> consultation with GEI, so that critical areas can be monitored sufficiently. <br /> The control points should be monitored weekly, after the initial installation. After several <br /> months of monitoring, the results should be reviewed by GEI for signs of slope movement. <br /> Depending on this review, the slope monitoring frequency can be adjusted up or down. <br /> Aggregate Industries Morrison Quarry GEI Consultants, Inc. <br /> South Quarry Highwall Design Technical Revision 29 August 2017 <br />