Laserfiche WebLink
Pond embankments, slopes, spillways and construction methods have <br />been designed according to such engineering factors as structural <br />integrity and stability, slope and surface stability; adequacy in <br />height, size and shape to provide sufficient volume for sediment <br />and detained water and selection of proper spillways and outlet <br />devices, passing of design storm events and proper outflow rates. <br />All ponds have been designed under the direction of a qualified, <br />registered professional engineer. <br />The purpose of the sedimentation ponds is not only to provide a <br />final measure to prevent additional contributions of sediment <br />outside the permit area, but also to provide a means of compliance <br />with all applicable effluent limitations, especially with respect <br />to total suspended solids or settleable solids, as required. <br />The effluent quality is regulated by Section 4.05.2 and by the <br />National Pollutant Discharge Elimination System (NPDES) Permit. <br />The NPDES Permit was issued by the State of Colorado Department of <br />Health under the National Pollutant Discharge Elimination System, <br />established as a result of the Clean Water Act (33 U.S.C. Section <br />1251, et. sea.). A copy of the approved NPDES Permit is found in <br />• Exhibit 7, Hydrology Information. <br />The engineering parameters for the various sedimentation ponds are <br />included in Exhibit 7, Hydrology Information. The engineering <br />design parameters for the various diversion ditches are also <br />included in Exhibit 7, Hydrology Information. Cross sections for <br />the sedimentation ponds and the designs for the emergency and <br />primary spillways are shown in Exhibit 7, Hydrology Information. <br />With the construction of the Streeter Fill and the future <br />development of the West Pit, the original drainages have been <br />relocated as shown on the Post Mining Topography (Map 19). The <br />details of these permanent diversions are set forth in Exhibit 12, <br />Experimental Practice Information, and Exhibit 7, Hydrology <br />Information. Note that for continuity the "Experimental Practice" <br />information in the permit is left intact to provide a historical <br />record of the Streeter Fill which is now an excess spoil fill built <br />to meet the standards of Rule 4.09 <br />2.05-23 <br />