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Drill Hole or Well Plugging - Sealing and Abandonment: All drillholes will be plugged, sealed, <br />and abandoned unless they are converted into a groundwater monitor well. Deeper drillholes will <br />be plugged with a minimum of 6 cubic yards (about 750 feet) of cement slurry - this is the off- <br />road transport capacity of a cement truck. Shallower drillholes will be plugged with between 3 <br />and 5 cubic yards of cement slurry (as appropriate). The cement slurry will be tremied into the <br />drillhole from the bottom of the hole, up through the target units. This will effectively plug and <br />seal all coal beds and potential groundwater aquifers to prevent vertical groundwater migration <br />and cross-contamination of aquifers. <br />Any remaining open drillhole interval will be filled with other suitable plugging material (plug gel <br />or vendor-specific grout compounds) and/or drill cuttings to within 5 feet of the ground surface <br />and the drillhole will be sealed with a surface plug consisting of at least 5 feet of cement. <br />Information on potential plugging materials, that are generally superior to conventional cement <br />grout, is provided in Appendix E. Surface casing, if used to keep the drillhole open, will be cut- <br />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 <br />drillhole locations will be accurately surveyed, and distinctly numbered, allowing for future <br />identification. Abandonment reports will be prepared and filed, as required by applicable <br />regulations. When no longer needed, as noted above, the groundwater monitor wells will be <br />plugged, sealed, and abandoned in essentially the same manner, with the stipulation that cement <br />slurry will be used for plugging the entire well interval. <br />Exploration Site Reclamation: Following completion of exploration activities (drilling, sampling, <br />and geophysical logging) for each exploration site, any drillholes not converted to monitoring <br />wells will be plugged, sealed and abandoned, as previously described, and exploration disturbance <br />will be reclaimed. In accordance with Rules 2.02.2(2)(f) and 4.21.4(4), excavations, artificial flat <br />areas, and embankments created during exploration will be returned to their original contour <br />promptly after such features are no longer needed for coal exploration. Site reclamation will <br />follow completion of exploration activities for each site as soon as reasonably practical, <br />recognizing however, that certain reclamation activities may be coordinated to take advantage of <br />equipment and personnel availability. Seeding of reclaimed exploration sites will occur during the <br />first favorable seeding period (typically late fall [preferred], or early spring) following completion <br />of site reclamation. The following summarizes the steps and general sequence for reclamation of <br />exploration disturbance areas: <br />1) On completion of exploration activities at a given site, all trash, debris, and exploration <br />equipment and supplies will be removed from the site. <br />2) Drilling fluids in mud pits will be allowed to dry, or they may be pumped from the mud pit <br />for off-site disposal. Mud pits or excavated trenches will be backfilled with the excavated <br />material and compacted to minimize any settling. Any excess drill cuttings will be spread <br />over the drill pad, and the drill pads regraded to approximate their original configuration and <br />blend with the adjacent terrain. <br />3) Stockpiled or windrowed "A" and "B" horizon material will be redistributed at a uniform <br />thickness over disturbed areas. <br />2010 RC Admin Permit 6 2124110