Laserfiche WebLink
The specific structures to be removed during reclamation were previously identified <br />in Section 2.04.3, Operation Plan -Permit Area under the subtitle "Mine Facilities". <br />This section also addresses removal and disposal methods for each specific <br />structure. <br />Sealing of Underground Ooenings <br />Upon completion of mining, all underground openings including portals, boreholes <br />and wells will be permanently sealed unless they are to be utilized in conjunction <br />with ongoing monitoring or approved post-mining land uses. Methods for sealing <br />boreholes and monitoring wells are discussed both in Section 2.02, Coal <br />Exploration, and later in this section. <br />The five (5) main facility portals and the one (1) South Fan portal were <br />permanently sealed upon completion of mining to prevent access and provide a <br />hydrologic seal to minimize surface drainage from entering the underground <br />workings. All mine portals were sealed by filling the entries with compacted, <br />incombustible material combined with layers of bentonite for a distance of at least <br />25 feet, consistent with 30 CFR 75.1711. In order to ensure the long term integrity <br />of the portal seals, EFCI maintained adequate barrier pillars in adjacent areas and <br />installed cribs and posts where necessary immediately inby the portal seals to <br />prevent significant caving which might affect the seals. Once the main portal seals <br />were completed, the remaining portions of the mine entries between the portal <br />seals and the portal openings were filled with overburden material and demolition <br />debris in conjunction with subsequent backfilling activities. <br />During construction of the main facility portals, one portal seal was equipped with <br />a drain pipe that extended along the mine entry to the mine portal and then <br />vertically to the reclaimed surface. The intent of the drain system was to monitor <br />progressive flooding of the mine and associated water quality and to allow <br />discharge of ground water in the unlikely event that water levels were to reach the <br />portal seals. Further evaluation, however, has determined that the anticipated rate <br />of mine flooding will be very slow, limiting the potential effectiveness and value of <br />the drain system. EFCI has plugged and sealed the pipe consistent with applicable <br />requirements of Rule 4.07.3. <br />Backfilling and Grading <br />After removal of mine structures and facilities and sealing of mine openings are <br />completed, mine disturbance areas will be backfilled and regraded. EFCI has <br />specifically designed backfilling and grading activities to meet several objectives, <br />as follows: <br />2.05.4-8 Revised 5/13/04 <br />Permit Renewal RN-04 <br />