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progressed since the December 2008 readings. The previous movement in the B -axis of <br />BH05 -05 is interpreted to be due to settlement of the coal refuse. <br />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 Instrumentation Site Plan. Since installation three of the vibrating wire <br />piezometers have stopped working correctly (VWP -01, VWP -04 and VWP -07). The first <br />two VWP's were damaged and went out of service between June and August 2005. VWP - <br />07 went out of service between March and June 2011. Diagnostic tests indicate that <br />shorts have developed, likely due to damaged cables. Three additional vibrating wire <br />piezometers, designated VWP -06 through VWP -08, were installed at CWDA No. 2 in June <br />2009 to supplement the remaining piezometers. Completion details of these piezometers <br />are 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. Table 1. <br />Below summarizes their locations. During the December 17, 2013 site visit we were able <br />to extract information at installations VWP -051 06, 08, 09 and 10, which provides good <br />lateral representation of the coal waste in CDWA No. 2. <br />Table 1. Location of VWP's Installed May 18, 2012 <br />VWP ID # <br />Northing <br />Easting <br />SH Elev. (FT) <br />VWP Elev. <br />FT <br />VWP -09 <br />19482.57 <br />37675.72 <br />6109.9 <br />6074.9 <br />VWP -10 <br />19633.59 <br />37629.59 <br />6125.6 <br />6090.5 <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. Tablet. Summarizes the individual pore pressures since <br />installation for the currently active VWP`s. <br />Table 2. Summary of Active VWP Pore Pressures <br />VWP ID <br /># <br />Initial Pore <br />Pressure <br />(psi) <br />12/17/13 <br />Pore Pressure <br />(psi) <br />Difference <br />(psi) <br />Comments <br />VWP -05 <br />6.8 <br />2.5 <br />-4.3 <br />Steady decline <br />VWP -06 <br />11.3 <br />15.2 <br />+3.9 <br />Peak of 16.2 (3/14/13 <br />VWP -08 <br />12.2 <br />13.4 <br />+1.2 <br />Peak of 15.0 (12/21/09 <br />VWP -09 <br />1.5 <br />1.7 <br />+0.2 <br />Stead <br />VWP -10 <br />0.6 <br />1 0.7 <br />+0.1 <br />Stead <br />2013- REVISED 41 Quarter Monitoring Report PN #05- 126 -GEO <br />Page 2 of 6 <br />