Laserfiche WebLink
May 9, 2013 C- 1996 - 083 /Bowie No. 2 Mine SLB <br />Gullies from recent erosion were observed along ditch D -C6 on the southern outslope of the D Seam bench. It <br />appeared that the culvert (designated `36" Undesigned Culvert' on Map 15 -2) that flows to ditch D -C6 had been <br />blocked, causing flow over the road berm and out onto the outslope. At the time of the inspection, the culvert was <br />clear and flow was through ditch D -C6, as designed. There was no off -site damage as a result of the overflow, <br />since all of this area flows to Ponds B or C, and the gully was within the disturbed area boundary. <br />Some of the ditches on Gob Piles 2 and 4 were blocked, causing surface water runoff on the pile to pool and not <br />flow off of the pile as required by Rules 4.10.1(1)(a) and 4.09.2(7). Ditches Fl, F3, F12, F16, F17, F18, and F20 <br />were backed up with standing water because end dumped gob material and partially excavated cover material in <br />the central part of the pile prevented flow as depicted on Map 21 -3 of the currently approved permit application <br />package. Flow along ditches F5 and F6 was prevented by the temporary cover fill stockpile located on the second <br />bench above Pond F. <br />PROCESSING WASTE /COAL MINE WASTE PILES — Rule 4.10 and 4.11 <br />Drainage Control; Surface Stabilization; Placement: <br />Cover fill material was being excavated in the Gob Pile 2 expansion area. Because it was too wet to <br />access Gob Pile 4 to spread the excavated cover material, it was being temporarily stored on the second bench of <br />Gob Pile 2. <br />Refuse material had been end dumped in the Gob Pile 42 expansion area, where cover fill material had yet to be <br />excavated. Care should be taken when rehandling the refuse to ensure that cover fill material resources are not <br />contaminated with refuse material. <br />Refuse material was being hauled to Gob Pile 2, and being end dumped in the central area of the pile. At the time <br />of the inspection, end dumped material was located in the northernmost area of the pile, in the newly approved <br />expansion area, and on the western edge. No compaction operations were underway during the inspection, as none <br />of the end dumped material was dry enough for handling. Material on the western edge of Gob Pile 2 had been <br />placed at an approximate 2:1 slope; the approved slope angle is 3:1. <br />The manner of end dumping material throughout the pile is inconsistent with Rule 4.09.1(1)(c), which requires <br />placement of waste material in a controlled manner to ensure stability of the fill. The pace of compactive effort <br />does not appear to meet the requirements of Rule 4.09.1(7), which requires concurrent compaction of fill material <br />that is placed on the refuse pile. <br />As discussed above, under the "Hydrologic Balance" section of this report, water was pooling in several of the <br />drainage ditches on Gob Piles 2 and 4. Additionally, water was pooling between piles that had been end dumped <br />and also along the haul road on Gob Pile 2. <br />The combination of pooled water and steepness of the end dumped material on Gob Pile 2 would indicate that the <br />required factor of safety of 1.5, per Rule 4.10.4(2) is not being maintained. <br />Number of Partial Inspection this Fiscal Year: 13 <br />Number of Complete Inspections this Fiscal Year: 3 <br />Page 3 of 15 <br />