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Ms. Diane Delaney - 2 - February 23, 1993 <br /> At the meeting of December 2, 1992, MCR outlined in more detail how this will <br /> be accomplished, and provided cross-sections of the final topography. The <br /> Division accepts these proposals for the benches themselves, with the <br /> additional requirement that sediment ponds remain until vegetation is <br /> established. <br /> We concur with MCR that the portal bench outslopes have been reaffected by MCR <br /> since the issuance of the DMG permit, and that is is the responsibility of MCR <br /> to reclaim them. We are encouraged by the results of test plots established <br /> by MCR that indicate it is possible to establish vegetation on these areas , <br /> and that the outslope material seems suitable for a plant growth medium. <br /> We concur that the biggest challenge for successful revegetation of the <br /> outslopes will be the development of an appropriate seedbed that will remain <br /> in place long enough for vegetation to become established, given the <br /> steepness of the slopes . The use of sewage sludge as an organic amendment to <br /> help bind the soil , provide a source of nutrients , and increase infiltration <br /> is a good idea. We believe that the use of slash to provide additional soil <br /> stability during vegetation establishment should also be included. We will <br /> investigate which authorities should be contacted regarding the use of sludge <br /> for agricultural purposes , and pass the information along to you as we obtain <br /> it. <br /> The Division concurs that hydromulching, or some other form of broadcast <br /> seeding will be preferable to drillseeding these steep slopes . Remember that <br /> when broadcast seeding methods are used, the rate of seed application is <br /> doubled over that of drillseeding methods . We recommend that, given the slope <br /> steepness , an even heavier rate be used. <br /> Your suggestion about installing catchment basins and/or silt fences at the <br /> toes of the portal bench outslopes, to further minimize sediment loss , is a <br /> good one. We will work with MCR on allowing access to accomplish this <br /> activity. <br /> Backfill /Grading <br /> The revised backfill and grading plan proposes a reduction in the amount of <br /> transported fill to be used around the prep plant office area. The new MCR <br /> plan would use material readily available in the areas where it is needed. <br /> The Division agrees that the use of coal refuse as backfill (as currently <br /> approved) is not desirable and may be in fact be infeasible due to the cover <br /> requirements for coal mine waste. We are receptive to the idea of achieving <br /> final contours utilizing materials available on site. However, final grades <br /> must not exceed the material angle of repose , unless it can be demonstrated <br /> that these grades meet a safety factor of 1 .3. All highwalls in the prep <br /> plant area must be eliminated. <br /> Remnant coal from the stockpile area can be placed against cut slopes , as long <br /> as four feet of final cover, including topsoil , is placed over it. <br /> One final item requested by MCR regarded abandonment of the reclaim tunnel <br /> that runs under Road A from the raw coal storage area to the prep plant. This <br /> is a large culvert and will need to be completely filled with rock or soil <br /> type material if it is left in place. If this cannot be accomplished, it must <br /> be removed . <br />