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970 - 249 -6828 ■ 800 - 865 -9847 (fax) ■ 222 South Park ■ Montrose, Colorado 81401 ■ www.dowl.com <br />■ ■ ■ ■ ■ ■ ■ <br />BOWL <br />April 17, 2015 <br />H udd leston- Berry Engineering and Testing, LLC <br />640 White Avenue <br />Grand Junction, CO 81501 <br />Attention: Mike Berry, PE <br />SUBJECT: First 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 March 11, <br />2015 for the first quarter reporting period, 2015 at Coal Waste Disposal Area No. 3 (CWDA No. <br />3). A graphic plot of measured pore pressures over time is presented on the attached Figure <br />1, and numerically in Table 1 below. Table 1 summarizes the initial, prior and current readings <br />and the difference in individual pore pressures since installation and prior readings. <br />Table 1. Summary of Pore Pressures <br />VWP ID # <br />Initial Pore <br />Pressure <br />10/31/14 <br />(Psi) <br />2/4/15 Pore <br />Pressure <br />(psi) <br />3/11/15 Pore <br />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 />7.7 <br />6.5 <br />-3.9 <br />-1.2 <br />VWP -A Shallow <br />4.7 <br />3.8 <br />4.1 <br />-0.6 <br />+03 <br />VWP-13 Deep <br />1 0.2 <br />1 -0.1 <br />1 -0.1 <br />1 -0.3 <br />0 <br />VWP-13 Shallow <br />13.9 <br />13.7 <br />13.2 <br />-0.7 <br />-0.5 <br />VWP -D <br />7.1 <br />8.0 <br />7.7 <br />+0.6 <br />-0.3 <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 mcandorf olow/.com. <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 Q1 VWP Report 4 -17 -15 <br />Project #7131.74108.01 <br />Page 1 of 1 <br />