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<br />At present pond 005 is non-operational due to structural failure. All <br />mine water is diverted to the series of ponds 002, 002A and B. The <br />sediment control system has been reviewed by the Division. Designs for <br />the sediment control system are found on pages 2.05-9 through 2.05-16 and <br />in Exhibit 6 of the renewal application. <br />Surface runoff from the disturbed area is contained by sediment pond <br />nos. 3 and 4. Locations of these ponds appear on Map 11, Sediment and <br />Surface Water Control Plan. These ponds are capable of containing the <br />runoff generated by a 10-year, 24-hour storm event and are designed to <br />contain 0.1 acre-feet of sediment per acre of disturbed area. The ponds <br />are both equipped with principal spillways and emergency spillways <br />capable of passing the peak flow from a 25-year, 24-hour storm event. <br />The principal spillways are gated, but the gate will be opened a <br />calculated amount to allow for automatic dewatering with a detention time <br />of 24-hours. A series of ditches route disturbed drainage water to the <br />ponds and undisturbed drainage around the disturbed area. These ditches <br />are capable of handling the peak flow from a 10-year, 24-hour storm event. <br />The applicant has received Division approval to employ alternative <br />sediment control measures for an additional five areas; the topsoil pile <br />south of the substation, the substation south of the Industrial Building, <br />the substations and power drop east of the mine, and the service hold and <br />water tank area. In several of these areas the disturbed areas are <br />covered with cement or gravel, therefore, little surface erosion occu rs. <br />The rest of these areas are provided with alternate sediment control <br />measures such as silt fences, ditches, berms or catch basins. All <br />alternative sediment control areas have been designed and constructed to <br />meet all applicable effluent limits. <br />VI. Hydrologic Balance: Ground Water - Rules 2.04.5, 2.04.7, 2.05.3(4 <br />r-rn:-zi ----x-~ <br />Information regarding the occurrence, quantity, and quality of ground <br />water is found on pages 2.04-7 through 32 of the revision application <br />document together with Exhibits 6, B, 9, and 10 and Map 7. <br />All of the sedimentary rock strata exposed over the mine area together <br />with the Maxwell coal seam mined at the Golden Eagle Mine are members of <br />the Raton Formation. This formation is 1,200 to 1,600 feet thick. The <br />Maxwell seam is found near the middle of the Raton Formation and acts as <br />a laterally extensive aquifer, but has limited permeability and poor <br />water quality. Above the Maxwell seam, interbedded sandstone, siltstone, <br />and shale rock units su stain localized perched aquifers. These aquifers <br />are laterally and vertically discontinuous and have low permeabilities, <br />but do provide provide limited quantities of ground water for watering <br />livestock and for wildlife in the area of the mines. <br />The Vermejo Formation underlies the Raton Formation. The Vermejo <br />Formation, like the Raton Formation, consists of interbedded and <br />lenticular shales, siltstones, sandstones, and coals. Some of the <br />sandstones and siltstones are very localized, discontinuous aquifers. <br />None of the wells inventoried in the general area of the mine appear to <br />be completed in this formation. <br />-6- <br />