Laserfiche WebLink
section (2,500 feet) of the access road will be reclaimed unless otherwise approved by the CDRMS. The soil <br />windrowed or stockpiled adjacent to the road will be seeded with the rangeland seed mixture. <br />Rockdust Tank <br />After removal of the rockdust tank and cement pad, the pit -run gravel of the truck access /unloading area will be <br />dispersed across the .5 acres of disturbance. The area will be ripped before the stockpiled soil is reapplied and <br />reseeded. <br />7 -North Escape Shaft <br />When the facility is no longer required, the shaft will be plugged, and the site graded, re- soiled, and revegetated. Steps <br />required to abandon the shaft will include removal of surface structures, demolition of the concrete foundation and <br />piers, and sealing of shaft. After the surface structure is removed, the broken -up foundation and piers will be put down <br />the shaft, and decking will be suspended in the shaft 10 feet below - grade. The support beams and decking will be <br />suspended from the steel casing by steel straps (i.e. I -beams or similar support structures) welded to the support beams. <br />The steel straps will be welded to the existing 48 -inch diameter casing. Once this is completed, a 24 -inch thick <br />reinforced concrete slab will be poured in -place over the previously placed decking. The void from the top of the <br />concrete slab to within 5 feet of the surface will be backfilled with inert fill material (approximately 1.4 CY) from the <br />surrounding area. The next 2 feet of the shaft will then be filled with concrete to form a surface plug for the shaft. <br />Suitable fill material will be placed in the remaining 3 feet of the shaft (approximately 1.4 CY), and then the site <br />will be re- soiled and revegetated. The redistributed soil will be seeded with the pastureland seed mixture. <br />NMD Power Borehole <br />Upon completion of mining, and when the power borehole is no longer needed, the facilities will be removed and the <br />site reclaimed. Removal of the surface facilities will involve dismantling of surface structures, which includes the <br />powerline, transformer and pad, road and culvert, and building. After the facilities are removed, the site will be <br />regraded to blend with the existing terrain, the stockpiled soil will be redistributed over the area, and the power <br />borehole pad and reclaimed road segments will be seeded with the pastureland seed mixture. The entire road will be <br />chisel- plowed after removing the geotextile. <br />Drillhole or Well Plugging and Sealing, and Well and Pipeline Reclamation and Abandonment <br />All drillholes will be plugged, sealed, and abandoned unless they are converted for long -term use as a monitoring or <br />water - supply well. Deeper drillholes will be plugged with a minimum of 6 cubic yards (about 750 feet) of cement <br />slurry — this is the off -road transport capacity of a cement truck. Shallower drillholes will be plugged with between <br />3 and 5 cubic yards of cement slurry (as appropriate). The cement slurry will be tremied into the drillhole from the <br />bottom of the hole, up through the target units. This will effectively plug and seal all coal beds and potential <br />groundwater aquifers to prevent vertical groundwater migration and cross - contamination of aquifers. <br />Any remaining open drillhole interval will be filled with other suitable plugging material (plug gel or vendor - <br />specific grout compounds) and/or drill cuttings to within 5 feet of the ground surface and the drillhole will be sealed <br />with a surface plug consisting of at least 5 feet of cement or other suitable permanent plugging material. Surface <br />casing will be cut -off at or below grade. Reclaimed drillhole locations will be marked with either a steel fence post <br />or a metal survey cap at, or below, ground level (used where agricultural cropping occurs). All drillhole locations <br />will be accurately surveyed, and distinctly numbered, allowing for future identification. Abandonment reports will <br />be prepared and filed, as required by applicable regulations. Similarly, monitoring wells, when no longer needed, <br />will be plugged, sealed, and abandoned in essentially the same manner, with the stipulation that cement slurry will <br />be used for plugging the well. <br />All pipelines will be plugged and abandoned in- place. Pipelines will be drained, cut -off at least 3 feet below the <br />natural or reclaimed surface, plugged or capped, and the plugged ends will be buried. Any access manholes or <br />MR10 -249 2.05-106.2 11/09/10 <br />