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970 249-6828 e 800 865. 9847 (mx) ua 222 SmAh e 'W onfiose, CC, 81401 e ����tir akG��d vivr <br />DOWL <br />January 8, 2016 <br />Huddleston -Berry Engineering and Testing, LLC <br />640 White Avenue <br />Grand Junction, CO 81501 <br />Attention: Mike Berry, PE <br />SUBJECT: Fourth Quarter Monitoring Report, Vibrating Wire Line Piezometers, <br />Bowie Mine No. 2, Coal Waste Disposal Area No. 3 <br />Dear Mr. Berry, <br />DOWL has conducted quarterly monitoring of installed vibrating wire piezometers on December <br />19, 2015 for the fourth quarter reporting period, 2015 at Coal Waste Disposal Area No. 3 <br />(CWDA No. 3). A graphic plot of measured pore pressures over time is presented on the <br />attached Figure 1, and numerically in Table 1 below. Table 1 summarizes the initial, prior and <br />current readings and the difference in individual pore pressures since installation and prior <br />readings. <br />Table 1. Summary of Pore Pressures <br />VWP ID # <br />Initial Pore <br />Pressure <br />10/31/14 <br />(psi) <br />9/26/15 Pore <br />Pressure <br />(psi) <br />12/19/15 <br />Pore Pressure <br />(psi) <br />Difference <br />Since <br />Installation <br />(psi) <br />Difference <br />Since Last <br />Reading <br />(psi) <br />VWP-A Deep <br />10.4 <br />6.0 <br />7.0 <br />-3.4 <br />+1.0 <br />VWP-A Shallow <br />4.7 <br />4.9 <br />4.6 <br />-0.1 <br />-0.3 <br />VWP-13 Deep <br />1 0.2 <br />1 0.3 1 <br />0.1 1 <br />-0.1 <br />-0.2 <br />VWP-13 Shallow <br />13.9 <br />15.6 <br />14.7 <br />+0.8 <br />-0.9 <br />VWP-D <br />7.1 <br />7.4 <br />7.0 <br />-0.1 <br />-0.4 <br />If you have any questions regarding this letter or the instrumentation monitoring at CWDA <br />No. 3, please don't hesitate to contact me at (970) 497-8827 or wpandorfOolow/.corn. <br />Respectfully Submitted, <br />DOWL <br />Wayne Pandorf, P.E. <br />Sr. Geotechnical Engineer <br />Enclosure: Figure 1 — Vibrating Wire Piezometer Data Graph <br />Bowie CDWA 3 Q4 VWP Report 1-8-16 <br />Project #7131.74108.01 <br />Page 1 of 1 <br />