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• III IIIIIIIIIIIII III INSPECTION REPORT .; ~~'~~~~~-~••.•r,;., <br />J~ 999 : -• ''S; •: <br />Site: National King Coal Mine, Hesperus, Colorado •~' ~~ 'J •".~-`- ' '': <br /><'~ ~ t <br />Inspected By: Don R. May, P.E., Project Engineer _;, : / ~ ` :i <br />Inspection Date: Quarterly Inspection, January 7, 1998 `~1,./y~~ -°-• <br />AL .~.' <br />Ponds: The east and west sedimentation ponds and their embankments appear m good <br />condition. The west pond is shown in photograph 1. The inlet channel from the lower <br />yard/road area to the east pond is partially blocked by piles of dirt as seen in photograph <br />2 (right, middle). The swale across the entrance road between the ponds that diverts <br />runoff from the road into the east pond can also be seen in this photograph. It is formed <br />by the hump in the road located in the middle, left of the photo. <br />Drainage Ditches: The east side and west side drainage channels appear in good general <br />condition although they are covered by snow which precludes detailed inspection. The <br />drainage ditch at the top, back of the pile is shown in photograph 3. As seen, recent <br />waste rock has been placed in such a way that blocks the channel. A defined, continuous <br />channel should lie cut at this location. Photograph 4 shows the yard area from the top of <br />the pile. Drainage in the yard appears to be working well. <br />The outlet to a new 24' CMP which replaced an older culvert is shown in photograph 5. <br />This pipe begins at a drop inlet in the yard, across from the scale house and terminates in <br />the large ditch across from the office. The old concrete pipe, not in use, is see to the left. <br />This change in pipes should be included in a revision of the drainage plan for the mine. <br />All other ditches and structures were inspected and appear in good operating <br />condition. All drainage features, except the new 24" CMP, have been constructed and are <br />operating as stated in the drainage plan submitted to the Division of Minerals and <br />Geology. <br />Coal Waste Pile: There are no visible signs of structural instability on the waste pile. <br />Photographs 3 shows a portion of the top of the pile and photograph 6 the face. The <br />slope on the face appears to exceed the design slope of 3:1 (horz:vert). This should be <br />confirmed and adjustments made to the face as needed to assure the design slope is <br />met. In addition, it is important that the waste material be placed in lifts not to exceed 12" <br />to 18" and that compaction results in the density stated in the design report. It is not <br />possible to determine this by visual inspection and therefore the density should be <br />periodically checked by measurement. The highwall and other slopes at the site appear <br />stable. <br />As reported last quarter, it appears that waste material is being generated in larger <br />amounts that initially expected and hence the waste pile is approaching the final design <br />volume prematurely. This concern has being address by the redesign of the waste pile <br />that is currently under review by the Division of Minerals and Geology. <br />Except for the items mentioned above the fill on the waste pile has been constructed ~'~ <br />as specified in the design approved by the Division of Minerals and Geology. <br />