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Vibrating Wire Piezometers <br />Five vibrating wire piezometers, designated VWP -01 through VWP -05, were installed in <br />coal refuse at CWDA No. 2 in June 2005. The piezometers were grouted in drilled <br />boreholes as described by BGI (2006). Piezometer locations are presented on the <br />attached site plan. Since installation two of the vibrating wire piezometers have stopped <br />working correctly (VWP -01 and VWP -04). Diagnostic tests indicate that shorts have <br />developed, likely due to damaged cables. Three additional vibrating wire piezometers, <br />designated VWP -06 through VWP -08, were installed at CWDA No. 2 in June 2009 to <br />supplement the remaining plezometers. Completion details of these piezometers are <br />described by BGI (2009). Due to damage to existing vibrating wire piezometers, an <br />additional two VWP's (VWP -9 and VWP -10) were installed on May 18, 2012. During the <br />December 17, 2013 site visit we were able to extract information at installations VWP -05, <br />06, 08, 09 and 10, which provides good lateral representation of the coal waste in CDWA <br />No. 2. <br />Pore pressures measured to date are presented on the attached Pore Plat figure. Pore <br />pressures at all recording piezometers were constant or decreasing during the 4th <br />quarter of 2013. Those reading indicate generally stable conditions at those piezometer <br />sites. Readings at these piezometers have generally decreased since they were installed. <br />This is a good indication that internal drainage is occurring and that waste material is <br />dewatering due to consolidation and trending towards equilibrium. All measured pore <br />pressures are well below the pore pressures at failure for similar confining pressures for <br />the CU triaxial shear tests that have been conducted as part of the on -going stability <br />evaluation for CDWA No. 2. <br />Pore pressures are anticipated to continue to decrease as drainage occurs. In any event, <br />on -going monitoring of all piezometers is recommended to monitor pore pressure <br />responses to the on -going refuse placement. Otherwise, the measured pore pressures <br />are consistent with the revised stability evaluation for the coal refuse performed by BGI <br />(2008). <br />Site Visit Observatig s <br />During my site visit on December 17, 2013 with Mr. Gary Harding (Bowie Resources) and <br />Ms. Tamme Bishop of J.E. Stover & Associates, no gob stockpiling or processing was <br />being performed at CWDA No. 2. It is our understanding that, due to winter conditions, <br />Pile #2 will not be used until spring. Ms. Bishop and I walked the perimeter of Pile #2, <br />including the drainage ditch upslope of the pile, and I did not observe any surface <br />failures in either compacted or uncompacted gob. The air temperature was approximately <br />40 degrees F in sunny conditions and surface drainage from snow melt was observed in <br />several of the drainage culverts and ditches that serve Pile No. 2. <br />2013- 4t11 Quarter Monitoring Report PN #05- 126 -GEO <br />Page 2 of 5 <br />