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design for a subdrainage system in accordance with the requirements of Rule <br />4.10.3(1). <br />26. Placement and compaction of the Coal Mine Waste, as described on 2-27ii, is in <br />general compliance with Rule 4.10.4, Construction Requirements. There is <br />however no basis presented for the proposed compaction testing intensity of "a <br />minimum of 1 compaction test for every other compacted lift". <br />Please include rationale/justification for the proposed compaction testing <br />intensity, including considerations such as the equipment to be employed in <br />grading and compaction operations, equipment operator experience and <br />consistency, projected rate of waste material accumulation and projected <br />variability with regard to waste material source, physical characteristics and <br />moisture content. <br />27. Rule 4.10.4(5) states that 'following grading of the coal mine waste bank, the site <br />shall be covered with a minimum of 4 feet of... material." The revision proposes <br />the use of only 3 feet of cover material, approval of which would require that <br />physical and chemical analyses in accordance with Rule 4.15 be provided to the <br />Division. It may be that the assumption underlying the narrative is that a <br />minimum of 1 foot of topsoil would be replaced over 3 feet of coverfill soil, to <br />provide the required minimum of 4 feet of non-toxic cover, but this is not clear. <br />Please amend the narrative to clarify that a minimum 4 foot cover of non- <br />toxic material (coverfill and topsoil combined) would be replaced over the <br />waste disposal pile for final reclamation. <br />28. On amended page 2-35, narrative indicates that the sediment drying area will be <br />removed, and that material stored in the sediment drying area will be placed in the <br />coal mine waste disposal area once it is constructed. We realize that the existing <br />sediment drying area will be eliminated by construction associated with TR-16 <br />implementation. However, we are concerned that the amended plan does not <br />provide a facility for storage and drying of sediment periodically cleaned from <br />ditches and the sediment pond, prior to placement in the coal mine waste disposal <br />area. Depending on site specific conditions, including physical characteristics and <br />moisture content of the sediment, and phase of waste pile construction, it may or <br />may not be appropriate to place sediment cleanings directly into the coal mine <br />waste disposal area. Given the limited amount of space available within the <br />permitted disturbed areas, inclusion of a designated sediment storage/drying area <br />would appear to be warranted. <br />Please address this concern and amend the application as appropriate. <br />29. Table 4.2-12 Runoff Volumes - Summary of Ditch Sizes - A note at the bottom of <br />the table says "See Figure 2.2-3 for Rip Rap Location". Figure 2.2-3 does not <br />show locations of rip rap. <br />9