1993-06-08_GENERAL DOCUMENTS - C1981041

Home Browse Search

by the Division as appropriate (4. 10.2( 1 ) ) . Inspection shall occur quarterly and at critical construction periods . A copy of the inspection report will be retained at the mine office and a copy will be forwarded to the Division. 2 . An alternative subdrainage system for the coal mine waste area has been approved . The Division finds that such an alternative will ensure the applicable static safety factor , stability of the fill , and protection of the surface and ground water (4. 10.3(5)) . No underdrains will be constructed on Cameo Refuse Disposal Areas Nos . 2 and 3. The Roadside Refuse Area was not constructed with an underdrain , as well . 3. The permittee has conducted a demonstration based on physical and chemical analyses proposing that revegetation requirements of 4. 15 can be met with less than four feet of cover on the coal processing waste bank (4. 10.4(5) ) . This study will be finalized during the summer of 1993. A determination on the required cover depth will be made by DMG in September of 1993, based on results of this study. VII . Backfilling and Grading Following removal of mine facilities , buildings , and asphalt, and sealing of underground mine openings , all areas affected by surface operations will be backfilled and graded as necessary to stabilize slopes and promote successful revegetation. The anticipated final surface configuration for each affected surface area is depicted in Exhibits 6C through 12C, and Exhibits 26, 27 and 28 of the permit application . Calculations used to estimate the volume of cuts and fills are in Appendix V. During a previous review, the Division also requested cross sections of the proposed reclaimed surfaces . Cross sections V-V and W-W in Exhibit 26 of the application indicated that the permittee was proposing to leave the highwall and mine bench as they presently exist, rather than grade the area to approximate original contour. Rule 4. 14. 1 (2)(a) requires backfilling and grading to eliminate all highwalls and depressions , and Rule 4. 14.2 requires that the final graded slopes approximate the general nature of the pre-mining topography, eliminate the highwall and achieve a minimum static safety factor of 1 .3. The permittee subsequently revised the maps and plans to regrade the area to approximate original contour . The North Decline was backfilled and graded in the spring of 1992 . Material that had been piled above the portal area was dozed into the decline. A fair approximation of extrapolated original contours was achieved. The North Decline had been constructed prior to the Act so accurate records of pre-mine contours do not exist. The final reclaimed contours blend with landforms observed in the undisturbed surrounding landscape . The drainage channel of the unnamed drainage was reestablished through the regraded area and riprapped with 12-inch or greater riprap on the 7 .5 percent slope areas and 6 inches or greater on the 2 . 5 percent grades . Some settling of the fill has occurred above the portal location since the backfilling and final -33-