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• Back-up generation is provided to operate the HVSCS pumping system in the <br />event of a power outage. A transducer will be installed inside each of the HVSCS <br />vertical-riser pipes to measure solution levels in the PSSA following construction. <br />A solution level corresponding to 80 percent of the PSSA capacity will be <br />calculated and provided as part of the Certification Report submitted to the <br />OMLR after construction is completed. This level will be used to manage the <br />Phase 5 PSSA and higher levels will serve as an intensified monitoring and <br />reporting condition as discussed in Section 10.0 of this Project Description. <br />6.2.5 Low Volume Solution Collection System (LVSCS) <br />The LVSCS in Phase 5 is similar to the LVSCS approved for the Phase IV VLF <br />as part of Amendment No. 8. The Phase 5 LVSCS will overlie the lowermost <br />geomembrane liner in the PSSA and will consist of a series of four-inch diameter <br />PCPE pipes on 50-foot centers covered by a three-foot thick fill layer. The <br />LVSCS will be equipped with three 18-inch diameter riser pipes that lead outside <br />the PSSA into a shed. Pumps with transducers affixed will be installed in two of <br />the three of the LVSCS riser pipes (the third pipe will be maintained as a spare). <br />These devices will be operated continuously to maintain less than two feet of head <br />• on the lower geomembrane liner. This level will be used to manage the Phase 5 <br />LVSCS and higher levels will serve as an intensified monitoring and reporting <br />condition as discussed in Section 10.0 of this Project Description. For additional <br />design information, referred to Appendix 8, Volumes V and VI of this document. <br />6.2.6 Leak Detection System <br />As with previously approved phases of the VLF, a leak detection system ("LDS") <br />will be installed in the prepared subgrade beneath the SLF. The LDS for the Phase <br />5 area will be the same as previously approved and will consist of trenches <br />constructed along contour. The trenches will be one-foot wide by one-foot deep <br />and lined on the bottom and downgradient side with 40-mil smooth LLDPE. The <br />trenches will be lined with 12 ounces/square yard nonwoven geotextile and a <br />series of three-inch diameter PCPE pipe will be installed in the bottom to <br />facilitate drainage prior to placement of 3/4-inch minus leak detection fill ("LDF"). <br />The geotextile will be wrapped around the LDF and PCPE pipe before placement <br />of the overlying SLF. This system is designed to intercept leakage if it occurred <br />through the composite liner. Once intercepted, the flows would be directed along <br />the leak detection trenches, which are typically installed with a one percent grade, <br />toward sumps located on the perimeter of the VLF. These trenches also may <br />• collect shallow ground water after precipitation events. Additional details on the <br />Cripple Creek & Victor Gold Mining Company <br />Cresson Project Mine Life Extension <br />6-5