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970-249-6828 ■ 800-865-9847 (fax) ■ 222 South Park ■ Montrose, CO 81401 ■ www.dowl.com <br />Alaska ■ Ari_ona ■ Colorado ■ Montana ■ North Dakota ■ Oregon ■ Washington ■ Wyoming <br />Dawes <br />April 4, 2016 <br />Huddleston -Berry Engineering and Testing, LLC <br />640 White Avenue <br />Grand Junction, CO 81501 <br />Attention: Mike Berry, PE <br />SUBJECT: Summary Report, First Quarter 2016, Inclinometer and Active Vibrating <br />Wire Piezometer Data through March 2016, Bowie Mine No. 2, Coal <br />Waste Disposal Area No. 2 <br />Dear Mr. Berry, <br />DOWL conducted quarterly monitoring of inclinometers and vibrating wire piezometers at Coal <br />Waste Disposal Area No. 2 (CWDA No. 2), Bowie Resources, LLC. This report is intended to <br />cover the time period of January through March 2016. VWP data was obtained on 3-21-16 and <br />inclinometer data was also obtained on 3-21-16. Per DRMS and your instructions, vibrating wire <br />piezometer readings for all active piezometers are taken quarterly along with inclinometers. <br />Vibrating Wire Piezometers <br />Table 1. Summary of VWP Pore Pressure Readings <br />VWP ID <br /># <br />Initial Pore <br />Pressure <br />(psi) <br />12/19/15 <br />Pore Pressure <br />(psi) <br />3/21/16 Pore <br />Pressure <br />(psi) <br />Difference <br />Since <br />Installation <br />(psi) <br />Difference <br />Since Last <br />Reading <br />(psi) <br />VWP-05 <br />6.8 <br />1.9* <br />1.7 <br />-5.1 <br />-0.2 <br />VWP-06 <br />11.3 <br />15.0 <br />16.1 <br />+4.8 <br />+1.1 <br />VWP-08 <br />8.2 <br />10.0 <br />10.0 <br />+1.8 <br />0 <br />VWP-09 <br />2.8 <br />2.8 <br />2.8 <br />0 <br />0 <br />VWP-10 <br />-1.9 <br />-1.9 <br />-1.8 <br />+.01 <br />+0.1 <br />*Obtained on 1-8-16 <br />The physical locations of the piezometers are shown on the attached Instrumentation Site Plan, <br />Drawing 1. The graph of historical data through 5-21-14 is presented for reference as Figure 1. <br />A graph of active piezometers only is presented as Figure 2. <br />Inclinometers <br />Three inclinometers, designated BG05-04, BG05-05, and BG05-07, were installed at CWDA No. <br />2 in August 2005. The inclinometers were installed through the coal refuse and approximately <br />20 feet into the native foundation soils. The physical locations of the inclinometers are shown <br />on the attached Instrumentation Site Plan, Drawing 1. Baseline readings were taken on <br />8/10/05 and subsequent readings have generally been taken quarterly since that time. <br />Displacement curves for the prior three readings are presented as attachments to this letter for <br />each inclinometer. Axis "A" reflects deformation with depth in the direction of anticipated <br />movement (downslope), while Axis "B" is orthogonal to Axis A. Based on our most recent site <br />Bowie CDWA 2 VWP and Inclinometer Q1 2016 report <br />Project #7131.74525.01 <br />Page 1 of 2 <br />