Laserfiche WebLink
Bowie has routinely end - dumped gob material during winter months. This end - dumped material is <br />worked with dozers and track hoes to assist in the drying process. Trenches are cut through the end - <br />dumped material to allow better drainage. As conditions allow, the dried material is placed and <br />compacted. Steepness of slopes of the end - dumped material is not pertinent to the stability of the <br />pile. Permanent portions of the pile are comprised of compacted refuse that has been dried and <br />placed in a controlled manner. The end - dumped material may not achieve a long term factor of <br />safety of 1.5, but it remains stable so it can be dried, placed and compacted. The end - dumped <br />material is placed on permanent portions of the pile that are stable. The DRMS must allow Operators <br />the flexibility to end -dump gob material for drying. <br />NnV ItPM d <br />Failure to maintain a minimum static safety factor of 1.5, on Gob Pile #2, as required by Rule <br />4.10.4(2). <br />Gob Pile #2 is being constructed so its has a minimum longterm safety factor of 1.5. End - dumped <br />gob material obviously does not have the required long term safety factor. The Operator uses its best <br />efforts to place dry, place and compact end - dumped material. <br />The gob pile is under construction. End - dumped gob material is placed in the gob pile every day. <br />The gob arrives on the pile very wet. The gob is mixed, blended and turned in order to dry it. This <br />construction phase is required at all coal mine waste piles that receive gob from a wash plant. There <br />must be an allowance for the construction phase of operations. <br />NOV Item 5 <br />Rules 4.10.1(1)(a) and 4.09.2(7). <br />Failure to divert surface runoff from the fill surface to stabilized channels off the fill which will safely <br />pass the runoff from a 100 -year, 24 -hour precipitation event on Gob Pile #2 and Gob Pile 94, as <br />required by Rules 4.10.1(1)(a) and 4.09.2(7). <br />Rule 4.09.1(9) states the final configuration of the fill shall be designed to minimize the erosion. <br />Terraces may be utilized to control erosion and enhance stability if approved by the Division and <br />consistent with 4.14.2(2). <br />Rule 4.09.2(4) states the final configuration of the fill shall be suitable for the approved post mining <br />land use. Terraces may be constructed on the outslope of the fill if required for stability, control <br />erosion, to conserve soil moisture or to facilitate the approved post mining land use. <br />Rule 4.10.4 details construction requirements for coal mine waste piles. Rule 4.10.4(5) states in part <br />"Following grading of the coal mine waste bank, the site shall be covered with a minimum of 4 feet of <br />the best available non -toxic and non - combustible material in accordance with 4.06.1, and in a manner <br />that does not impede flow from subdrainage systems ". This statement implies that a coal mine <br />waste bank may be rough graded during construction and graded to final contours prior to placement <br />of cover. <br />