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• The specific structures to be removed were previously identified in Section 2.04.3, <br />Operation Plan - Peanit Area, under the subtitle "Mine Facilities". This section also <br />addresses removal and disposal methods for each speafic structure. <br />Sealing of Underground Openings <br />Upon completion of [Hitting, all underground openings including portals, boreholes <br />and wells will be permanently sealed unless they aze to be utilized in conjunction with <br />ongoing monitoring or approved post-mining land uses. Methods for sealing <br />boreholes and monitoring wells aze discussed both in Section 2.02, Coal Exploration, <br />and later in this section. <br />The five (5) Southfield Mine portals will be permanently sealed upon completion of <br />muting to prevent access and provide a hydrologic seal to prevent surface drainage <br />from entering the underground workings. The portals will be sealed by constructing a <br />concrete block wall approximately 25 feet inby the portal openings. The solid block <br />wall, which will be constructed as illustrated by Figure 21, Typical Portal Seal, will be <br />• keyed into the mine entry at least six (6) inches on all sides and a MSHA approved <br />mine sealant will be spread on the outer face of the barrier to provide a positive water <br />seal. In order to assure the long-term integrity of the portal seals, EFCI, as part of the <br />MSHA Roof Control Plan, will maintain adequate barrier pillazs in adjacent azeas and <br />will utilize timber cribs, posts or other appropriate means inby the portal seals to <br />prevent significant caving which might affect the seals. Once the portal seals aze in <br />place, the entry between the portal seal and the portal opening will be filled with <br />overburden material in conjunction with subsequent backfilling activities. <br />Backfilling_and Grading <br />After removal of any mine structures and facilities which will not be retained and <br />sealing of mine openings aze completed, mine disturbance azeas will be backfilled and <br />regraded. EFCI has specifically designed backfilling and grading activities to meet <br />several objectives; <br />• <br />Minor Revision MR-41 2.05.4-8 Revised December 200] <br />