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INTEROFFICE MEMORANDUM <br />Date: 25 June 2015 <br />To: Jason Musick, Lead Specialist <br />From: Marcia L. Talvitie, P.E. <br />Subject: Bowie No. 2 Mine (Permit No. C-1996-083) <br />Review of 1st Qtr 2015 Coal Mine Waste Bank and Instrumentation Report <br />I have reviewed the above -referenced report, submitted by J.E. Stover & Associates on behalf of Bowie <br />Resources, LLC on Apr. 22, 2015 (and revised page 1 submitted May 18, 2015). Approved Placement, <br />Compaction, and Inspection requirements for Coal Mine Waste (Gob) are found in Volume IX, pp. 12-14 <br />and Volume XI, pp. 8-9. The information provided in the subject report adequately addresses the <br />requirements. Please see the highlighted text below for my comments on the frequency of VWP <br />monitoring. <br />Compaction Testing <br />During this quarter, coal mine waste placement and compaction activities occurred at both Gob Pile #2 <br />and Gob Pile #3. All compaction testing was performed by Huddleston -Berry Engineering & Testing, LLC <br />(HBET). A total of 33 compaction tests were performed: 18 (on Mar. 27, 2015 at Gob Pile #2), and 14 <br />(on Mar. 28, 2015) at Gob Pile #3. Coordinates and elevation of each test point are provided in map and <br />tabular form. All locations tested achieved the requisite minimum 90% of Maximum Dry Density. <br />Accurate moisture contents for each sample were measured in the laboratory. Two new Moisture - <br />Density curves (15-0115 and 15-0130) were included with the report. No new gradation and Atterberg <br />limit data was submitted. <br />Instrumentation Report <br />Inclinometers are installed on the lowermost bench of Gob Pile #2; measurements are made quarterly. <br />The results for this quarter indicate no significant movement has occurred. <br />Vibrating Wire Piezometers (VWPs) are installed at Gob Pile #2 (5) and at Gob Pile #3 (also 5). The VWPs <br />were installed and are monitored on a regular basis by Buckhorn Geotech (now by DOWL). In a letter <br />dated Apr. 10, 2014, the Division directed BRL to increase the monitoring frequency from quarterly to <br />monthly. BRL committed to the increase in a letter dated Apr. 11, 2014. Monthly monitoring was <br />continued through Oct -2014, with an additional quarterly reading taken on Jan. 6, 2015 (representing <br />the 4th Qtr). By Email on Feb. 10, 2015, we approved BRL's reverting to once per quarter through the 15` <br />Quarter of 2015. VWP-06 showed a slight increase in pore pressure during the 151 Qtr. I recommend <br />that the Division review the 2nd Quarter data, as soon as it is available, and determine then whether <br />BRL should return to monthly monitoring of VWP-06 and -08. <br />This concludes my review of the 15Y Quarter 2015 Coal Mine Waste Bank and Instrumentation <br />Monitoring Reports. Please let me know if you have any additional questions. <br />cc: Dan Hernandez, DRMS <br />