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• BLEEDER SHAFT PAD SMALL AREA EXEMPTION (SAE) Peabody Energy Twentymile Coal Company (TCC) is requesting an SAE for the proposed Bleeder Shafr Pad Area located at the Twentymile Coal Foidel Creek Mine site as shown on Figure 1, Bleeder Shafr Pad SAE. Drainage and sediment control for the Bleeder Shaft Pad site is provided by: • two (2) up-gradient diversion ditches (to divert undisturbed runoff around the facility) • two (2) down-gradient drainage ditches (to collect runoff from the distwbed area) • gravel swfacing of the pad • the use of 20-inch diameter sediment logs around the lower portion of the topsoil stockpile • the use of Cwlex single net (Cwlex I) erosion control blankets over seeded cut and fill slopes, and • the combination of a rock filter (2-fr rock berm) and grass filter. The combined runoff from the distwbed area will be collected in the down-gradient drainage ditches and conveyed, ftrst through the graded rock filter, and then through the grass filter prior to exiting through the undisturbed natwal vegetation between the pad and Fish Creek. As a relatively small area (approximately 4.25 acres), and given the • effectiveness of the drainage and sediment control measwes, the additional disturbance that would be involved in constructing a sediment pond is not warranted. Sediment contributions from the small disturbed area can effectively be controlled using the stated Best Management Practices (BMPs), and therefore falls under a Small Area Exemption (SAE), consistent with applicable provisions of Rule 4.05.2(3)(b). There will be no discharge or mixing of mine water with surface drainage from the site. Given the limited site azea, a pad area that is swfaced with gravel, the drainage and sediment control measures, and the effectiveness of the BMPs to reduce the peak settleable concentration to 0.23 ml/L, TCC believes an SAE is justified. The estimated peak flow and runoff from the site for the 10-year 24-hour storm event is 1.52 cfs and 0.17 ac-ft, respectively. The peak settleable concentration in the runoff from the proposed Bleeder Shafr Pad area is less than natural settleable concentrations for runoff from undistwbed lands, given similar conditions. The up-gradient diversion ditches will be triangular ditches designed to safely divert the peak flow from the 10-year, 24-how storm with 1.0' of freeboard and located as shown on Figure 1, Bleeder Shaft Pad SAE. The shaft pad will be constructed such that it slopes towards the gravel filter. The check dam and grass filter efficiency was modeled using the SEDCAD'~ 4 check dam and grass filter utility. The following is submitted to demonstrate that application of diversion ditches, drainage collection ditches, sediment logs, Curlex I erosion control blankets, a check dam and grass filter can effectively treat the runoff from the bleeder shaft pad. •