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RESPONSE
<br />Each exploration hole, borehole, well, shafr, or other exposed undergound opening will be cased, sealed, plugged,
<br />• or otherwise managed to meet the requirements of this Section. Based on both current and historic mining activities
<br />in the area, no acid or toxic drainage has been encountered. As demonstrated in this Section and further addressed
<br />under the discussion of Protection of Hydrologic Balance, TCC will prevent or minimize distwbance to the
<br />prevailing hydrologic balance by plugging and sealing drillholes and other undergound openings using accepted
<br />industry practices. Similazly, potential human, livestock, and wildlife safety issues in the permit and adjacent areas
<br />will be addressed, to the extent possible, by temporary or permanent sealing of mine openings.
<br />Any exploration hole, borehole, well, or other underground opening that is uncovered or exposed during mining
<br />operations, and which is not approved for ongoing water monitoring or use as awater-supply well, will be
<br />permanently sealed as set forth in Rule 4.07.3 for non-federal lease coal areas and as set forth in 43 CFR
<br />3484.1(a)(3) for federal coal leases. Any mine entry or opening which is temporarily inactive but is expected to be
<br />utilized at some futwe time will be protected by barricades or other appropriate access controls, fenced, and posted
<br />with signs to prevent access and to identify potential associated hazards. TCC will periodically inspect and
<br />maintain access controls and signage.
<br />Mine Portals
<br />When no longer needed for mining operations, the mine portals will be sealed, and the portal azea of the Foidel
<br />Creek Mine will be backfilled. The portal seals are patterned after the explosion-proof seals common to
<br />undergound coal mines, and will be constructed as double-row block walls keyed into the roof, floor, and ribs,
<br />prior to backfilling. The seals will be placed in competent Bound, well back from the highwall. Figure 15, Typical
<br />Portal Seals, gaphically illustrates the planned portal seal configuration. An equivalent cast in-place seal (ie:
<br />powed concrete wall) may be used as an alternative. Loose backfill material will be pushed into the open portal
<br />interval between the highwall and the seals to fill any remaining mine opening, and the portal face-up area and
<br />highwall will be backfilled to achieve the design postmining configuration. Once the portals are sealed, backfilling
<br />• will prevent access to the portal azeas and seals. Because the portal area will be completely backfilled, no drainage
<br />from the undergound workings will discharge from the portals to the nearby Foidel Creek drainage. TCC has not
<br />experienced any acid or toxic drainage from current or historic mining operations, so none is expected to be
<br />encountered following completion of undergound mining. Abandonment procedwes for portal areas are also
<br />described in the response to Rule 2.05.4.
<br />Ventilation Shafts and Boreholes
<br />Access to the inactive Fish Creek Ventilation Borehole will be controlled on a temporary basis by tack-welding a
<br />metal plate over the borehole casing. Final reclamation of the 36-inch diameter Fish Creek Ventilation Borehole
<br />will involve placing a plug at the bottom of the cased hole, cementing the cased hole from the plug to within three
<br />feet of the surface, be cutting-off the top three feet of the casing, backfilling the top three feet of the hole with soil,
<br />and seeding the site. Alternatively, the cased hole may be plugged and sealed by selectively placing cement plugs
<br />20 feet above and below the water-bearing units (i.e. Wadge Overburden, Twentymile Sandstone), filling the
<br />remainder of the cased hole with cement gout to within three feet of the surface, and completing site reclamation
<br />as outlined above.
<br />When mine ventilation shafts are no longer required to support ongoing or futwe mhtutg operations, associated surface
<br />equipment and facilities will be removed, the shaft will be plugged and sealed, and surface distwbance azeas will be
<br />reclaimed. Concrete pads will be broken up and foundations will be demolished to at ]east 2 feet below grade, and the
<br />resulting concrete debris will be disposed of in the shaft opening. The shaft collaz concrete will also be broken up and
<br />disposed of into the shafr opening, leaving an open space for the concrete slab and backfill material/shaft cuttings to be
<br />placed in the shaft void. A cement plug shall be placed in the bottom fifteen feet of the shaft and the remainder of the
<br />shaft will be filled with inert material including the shaft cuttings and collaz excavation materials. A cement plug will
<br />• be powed from ten feet below grade to within approximately three feet of the surface. The remaining three feet will be
<br />filled with soil and graded to blend with the sun•ounding terrain. Following plugging and sealing of the shaft; any
<br />cuttings remaining in the temporary mine waste disposal pit will be covered with excavated shaft collaz material. Cover
<br />TROS-51 2.05-119 03/13/06
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