2014-07-03_PERMIT FILE - C1981018A (5)

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• leak or spillage inside the preparation plant. Excess thickner water may be pumped into the sealed mine workings when necessary. Diesel fuel, gasoline and oil tanks are surrounded by berms to contain any major spillage from these sources. Refueling pads are surfaced and contoured such that any spillage would be naught in sumps. These sumps are inspected periodically and emptied as required. Spillage is disposed of along with other waste petroleum products in an acceptable fashion. The facilities layout including the locations of various water system supply and treatment facilities is presented on Map 15 ( "D" Portal Area Site Plan) and Map 22 (General Area). V.B Design, Construction and Operation of Ponds and Waste Banks V.B.1 General The following types of water retention structures are required as part of the Deserado Mine surface facilities: a. In situ or dugout - entire pond is at or below level of existing ground. b. Semi -in situ - part of pond is below existing ground but an embankment must be constructed along some portion of the pond perimeter. C. Embankment - entire pond is at or above level of existing ground. • All sedimentation ponds and sumps for refuse disposal areas RP -1, RP -2/3, RP-4 and RP -5A have been constructed. The constructed ponds are certified by a qualified professional engineer registered in the State of Colorado. All designed ponds have volumes less than 20 acre -feet and embankments less than 20 feet high. The ponds and sumps are listed in Table V -2. r� LJ The emergency overflow (Pond PP -1) and process water settling ponds (Pond PP -2) are part of the plant water supply and wastewater treatment runoff. They are lined wiih impervious membranes to prevent their contents from entering the groundwater system. Except for minor evaporation losses, they will have no adverse hydrological impact on the area. These ponds conform to the requirements set forth in Section 4.05.6. The sedimentation ponds are provided in compliance with Section 4.05.6. In accordance with Section 4.05.6(3)(c), the dewatering device on these ponds cannot be lower than the maximum elevation of the sedimentation storage volume. Therefore, portions of the runoff collected in these ponds are trapped in the volume below the inlet elevation of the dewatering device. This water leaves the pond either by evaporation, percolation or mechanical pumping. V.13.2 Dewatering Mechanics Natural Resource Conservation Service (NRCS) soils data indicate the bottom material in the embankment and semi - insitu ponds is moderately permeable and well drained. Until a sufficient amount of sediment accumulates in the ponds to adversely affect the Mid -Term Review 2002 (8/2002) V -5