Laserfiche WebLink
BOWIE RESOURCES, LLC <br />Bowie No. 2 Mine <br />Coal Mine Waste Bank Nos. 1, 2, 3 & 4 Inspections - 3d Quarter 2013 <br />On September 30, 2013, a visual inspection of the Bowie No. 2 Mine coal mine waste <br />banks was performed by Tamme Bishop. P.E. in accordance with Rule 4.10.2. This <br />inspection includes Gob Pile Nos. 1, 2, 3 and 4. Pile No. 1 is considered inactive. Pile <br />nos. 2 and 4 are essentially one combined pile. Pile no. 3 is located south of Bowie <br />Road. <br />I, J. E. Stover, P.E., have a wide variety of experience in the design and construction of <br />earth fill embankments. I viewed pictures and field notes from the visual inspection. <br />Nothing was observed during the inspection that would indicate the piles have a <br />potential for failure. No seepage was noted at the toe of the piles. The gob disposal <br />areas were dry to damp. All organic material and topsoil has been removed ahead of <br />the waste bank founding. The upper diversion ditches were inspected. There was a <br />tree in the east diversion ditch that needs removed. This ditch maintenance issue was <br />discussed with the Operator. <br />The first bench east of the haul road is covered with soil. The second bench east of the <br />haul road is mostly covered with a large subsoil pile. Most of the third and forth <br />benches east of the road are covered with soil. <br />Most of the coal mine waste was generated from the preparation plant. Approximately <br />220,100 tons of gob were hauled to the gob piles. Of that amount 180,100 tons were <br />hauled to piles no. 2 and 4 and 40,000 tons were hauled to pile no. 3. Coal mine waste <br />was hauled to gob pile no. 3 beginning on September 6, 2013. Coal mine waste is to <br />be placed in the pile in approximately horizontal lifts no more than 24- inches thick. The <br />coal mine waste is spread and compaction effort is provided by self propelled <br />sheepsfoot compactors. Ninety -two (92) compaction tests were performed during the <br />quarter. No compaction tests were taken at gob pile no. 3. Three tests failed. There <br />were six retests. A test passes if the test attains at least 90% of the maximum dry <br />density attained in a laboratory compaction test in accordance with ASTM D698. The <br />two quarterly tests that failed were retested and passed. The three density tests that <br />failed during previous quarters (738, 755B and 843) were retested during the current <br />quarter and passed. Test 738 failed the first test but passed the second retest. There <br />are no outstanding density tests failures at the end of the third quarter. <br />The middle central portion of the pile between benches 3 and 4 had very steeps slopes. <br />The material was being cast over the edge for compaction activities below. The slope <br />was (- 1.25H:1 V). This steep slope section has remained stable and does not show <br />any signs of instability. <br />A failure of the gob pile no. 1 would probably not be a hazard to human life. The pile is <br />located above a large flat bench. The bench is approximately 80 to 150 -feet wide <br />directly below the pile. Additionally, the gob pile sediment pond is located below the <br />-1- <br />