2014-10-07_PERMIT FILE - C1981018A (3)

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If, after regrading and revegetation, rills and gullies deeper than nine inches form in the regraded areas, they will be filled, graded or otherwise stabilized and the affected area revegetated. Drainage channels created in the regraded sections to conform to the natural terrain will be rip- rapped or otherwise protected as necessary to prevent erosion. Exposed unoxidized coal seams and refuse disposal areas will be covered with a minimum of 2.5 feet of the best available nontoxic, nonacid forming material. The 2.5' cover is a variance from the standard minimum cover of 4 feet. DRMS approved this variance (TR45) as a result of the revegetation study as described in Section V.G.1. Under such conditions, the compaction and drainage protection procedures will be as specified by the appropriate regulatory agencies. V.G.1 Reveaetation Study with Various Topsoil Depths The objective of this study was to investigate whether successful revegetation could be achieved with a topsoil /subsoil cover thickness of less than four feet. If the study showed that a lower topsoil /subsoil cover thickness could achieve successful revegetation, then BME would request a variance from the four feet cover requirement. The variance would establish the cover depth shown to be adequate by the study as the revegetation success standard. Greystone Consultants of Englewood, Colorado were retained to conduct the study, report the findings and recommend the appropriate cover thickness. • Several conclusions and recommendations were made as a result of this study: • While permanent revegetation success standards were not reached within the first five growing seasons, data indicated that the plots were maturing toward the standards. • Since vegetative cover and production data indicate higher levels on test plots with more soil cover, it appears depth of soil cover material is a limiting factor and that successful revegetation can be achieved with less than four feet of soil cover. • Results of this study indicated that aspect and adjacent land protection from wind played a role in revegetation success. North facing slopes out performed the south facing slopes in vegetative cover and production. • Initial poor vegetation development on the test plots might have been due to dry weather conditions. However, consideration was given to increasing the seeding rate for refuse area 1. • Consideration also was given to revising the seed mix for refuse area 1 to replace and add several forbs that would have a higher success in grassland communities. See Table V -13. Permit Renewal RN -6 (04/2014) V -22