Laserfiche WebLink
Please include in the sediment pond design installation of an energy <br />dissipator or riprap protection at the outfall of the pipe. <br />22. It appears that it may be necessary to armor the inlets to the sediment pond given <br />the significant velocities and flow volumes entering the north and east sides of the <br />pond. <br />Please evaluate this concern and amend the sediment pond design <br />information as warranted. <br />23. At the base of the D-7, Upland drainage an ephemeral stream is shown flowing <br />into the disturbance area east of the Coal Mine Waste Pile. It appears that this <br />flow should be ditched over to either D-7-1 or D-7-2 to avoid erosive problems at <br />the upper end of the D-7 drainage basin. <br />Please revise the D-7 ditch design accordingly. <br />Rule 2.05.3(8) Coal Mine Waste and Non-Coal Processing Waste <br />24. Various different terms are used in the application text and figures to describe the <br />proposed coal mine waste pile. <br />Please amend the various sections to be consistent, and use "Coal Mine <br />Waste Pile" since coal mine waste is the term defined in the regulations. <br />25. Page 2-27ii states that the operator does not plan to install an underdrain system <br />beneath the coal mine waste pile, unless "for cause" (i.e. springs or seeps are <br />discovered as the work progresses), referring to an alternate design allowed under <br />Rule 4.09.1(3) and 4.10.3(5). This is an incorrect application of Rule 4.09, which <br />refers instead to Disposal of Excess Spoil ("overburden"), and not to Coal Mine <br />Waste. <br />According to Rule 4.10.3(5), "an alternative subdrainage system may be utilized <br />after approval by the Division upon a thorough analytical demonstration that <br />such an alternative will ensure the applicable static safety factor, stability of the <br />fill and protection of the surface and groundwater in accordance with the <br />requirements of these Rules." Such an analytical demonstration has not been <br />provided for the Division's review. In fact, the Stability Evaluation prepared for <br />the operator by Buckhom Geotech, Inc. states that, "Foundation underdrains <br />should be designed and constructed to keep the near surface foundation soils <br />drained. We understand these drains are to be designed by others." <br />Please provide for inclusion in the application, either: 1) an analytical <br />demonstration in accordance with the requirements of Rule 4.10.3(5); or 2) a <br />8