2017-01-13_REPORT - C1996083 (3)

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970-249-6828 ■ 800-865-9847 (fax) ■ 222 South Park ■ Montrose, CO 81401 ■ www.dowl.com Alaska ■ Arizona ■ Colorado ■ Montana ■ North Dakota ■ Oregon ■ Washington ■ Wyoming BOWL December 20, 2016 Huddleston -Berry Engineering and Testing, LLC 640 White Avenue Grand Junction, CO 81501 Attention: Mike Berry, PE SUBJECT: Summary Report, Fourth Quarter 2016, Vibrating Wire Piezometers through December 2016, Bowie Mine No. 2, Coal Waste Disposal Area No. 3 Dear Mr. Berry, DOWL conducted quarterly monitoring of installed vibrating wire piezometers at Coal Waste Disposal Area No. 3 (CWDA No. 3), Bowie Resources, LLC. This report is intended to cover the time period of September through December 2016. VWP data was obtained on 12-14-16. A graphic plot of measured pore pressures over time is presented on the attached Figure 1, and numerically in Table 1 below. Table 1 summarizes the initial, prior and current readings and the difference in individual pore pressures since installation and prior readings. Table 1. Summary of Pore Pressure Readings VWP ID # Initial Pore Pressure 10/31/14 (psi) 9/26/16 Pore Pressure (psi) 12/14/16 Pore Pressure (psi) Difference Since Installation (psi) Difference Since Last Reading (psi) VWP-A Deep 10.4 4.2 4.0 -6.4 -0.2 VWP-A Shallow 4.7 4.1 3.9 -0.8 -0.2 VWP-13 Deep 0.2 0.4 0.2 0 -0.2 VWP-13 Shallow 13.9 12.3 11.9 -2.0 -0.4 VWP-D 7.1 5.9 5.6 -1.5 -0.3 If you have any questions regarding this letter or the instrumentation monitoring at CWDA No. 3, please don't hesitate to contact me at (970) 497-8827 or wpandorf@dow/.com. Respectfully Submitted, DOWL Wayne Pandorf, P.E. Sr. Geotechnical Engineer Enclosure: Figure 1 — Vibrating Wire Piezometer Data Graph Bowie CDWA 3 Q4 2016 VWP Report 12-20-16 Project #7131.74526.01 Page 1 of 1