2014-11-14_REPORT - C1996083 (2)

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= OTECN November 10, 2014 H udd leston- Berry Engineering and Testing, LLC 640 White Avenue Grand Junction, CO 81501 Attention: Mike Berry, PE Civil, Structural 8 Geotechnical Engineers 222 South Park Ave. • Montrose. CO 81 4U t Ph.. (970) 249 -6828 - FAX. {970) 249 -0945 SUBJECT: Monthly Summary of Vibrating Wire Line Piezometers, October 2014, Bowie Mine No. 2, Coal Waste Disposal Area No. 2 Dear Mr. Berry, Buckhorn Geotech, Inc. (BGI) conducted monthly monitoring of vibrating wire piezometers on October 31, 2014 at Coal Waste Disposal Area No. 2 (CWDA No. 2) for Bowie Resources, LLC (Bowie). Per DRMS and your instructions last month, vibrating wire piezometer readings are now only requested for VWP -06 and VWP -08 on a monthly basis with all active piezometers on a quarterly basis. Pore pressures measured to date are presented on the attached Pore Pressure Plot Charts, Figures 1 and 2, and in Table 1 below. Table 1 summarizes the initial and current readings and the difference in individual pore pressures since installation and since last month's readings. Table 1. Summary of VWP -06 and VWP -08 Pore Pressures VWP ID # Initial Pore 9/24/14 Pore 10/31/14 Pore Difference Difference Pressure Pressure Pressure Since Since Last (psi) (psi) (psi) Installation Reading (Psi) (Psi) VWP -06 11.3 17.1 17.0 +5.7 -0.1 VWP -08 8.2 9.7 9.7 +1.5 0 The physical locations of the piezometers are shown on the attached Instrumentation Site Plan, Drawing 1. The graph of historical data through 5 -21 -14 is presented for reference as Figure 1. A graph of active piezometers only is presented as Figure 2. If you have any questions regarding this letter or the instrumentation monitoring at CWDA No. 2, please don't hesitate to contact me at (970) 497 -8827 or mcandorfft uckhornoeo. com. Oct 2014 CDA 2 Monthly Instrumentation Report 11 -10 -14 PN #13- 231 -001 Page 1 of 2