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=, Mr. E. Peter Mattheis - 2 - July 5, 1990 Rule 2.05.3(3)(a) requires a narrative description and map of "all buildings, structures, and utility corridors". Coal conveyors and slurry pipelines are minimally described, and the application has no information on their locations. Rule 2.05.3(4) Table 4.3-6 on page 4-34 gives the 10-year/24-hour runoff event in acre-feet, and the 25-year/24-hour event in CFS. For the purposes of ditch design, the runoff in CFS is required for both storm events. No ditch is shown on Figure 4.2-3a running from the slurry holding tank to the existing system of diversions. A design and location are needed for this ditch, which would handle the separated slurry water in case of a system failure. NCEC should also commit to the immediate cleaning of any coal or waste spillage resulting from breakdown of the slurry-handling system. The Division's calculations indicate that all diversions on the site, with the exception of that running from Portal No. 1 to C7, may experience erosive velocities under the 10-year/24-hour peak flow. Sections of these ditches which are steeper than about 5 percent grade will need designed erosion protection. The role of Pond A in the slurry separation system is unclear. If it will receive water during normal operation, the application needs to clearly state the pumping rate of water from Pond A into the mine, in order to assure adequate runoff capacity in the pond. If Pond A receives water only during a system malfunction, the application should describe the means by which slurry water is conveyed from the separation system back to the mine during normal operation. As mentioned above, pipelines must be accurately mapped. Rule 2.05.3(5) The topsoil stockpile adjacent to the Vulcan Ditch, on the east end of the disturbed area, must be mapped on Figure 4.2-3a. The stockpile numbers in Exhibit 4.4-1 also need to be indicated on this map. Rule 2.05.3(9) Recent Rule changes require that underground development waste be treated as "Coal Mine Waste", subject to Rules 4.10 and 4.11. The application proposes to cover the two portal pads with 16 inches of topsoil as opposed to the 4 feet of cover required by Rule 4.10.4(5). However, Rule 4.10.4(5) allows exemptions based on requirements of 4.15 will be met. If less than the four feet is proposed, NCEC will need to undertake field trials to demonstrate adequate revegetation potential with the reduced cover. Rule 4.10.4(3)(a) requires that the remainder of the portal pads be constructed in two-foot compacted lifts, and shall be inspected quarterly by a registered professional engineer. Commitments to such actions should be included in the application. No designs have been included for the temporary coal processing waste stockpile. The aesigns and construction must meet the requirements of Rules 4.10 and 4.11.