2008-04-15_REVISION - M1980244 (351)

Home Browse Search

• The East Cresson Mine area is expected to be backfilled to promote free drainage to the surrounding natural ground surface as previously approved for Amendment No. 8. This backfilling will include the WHEX portion of the East Cresson to be mined as part of the MLE. Backfilling will be accomplished by end-dumping the material in "lifts" that range in height, depending on the logistics of truck hauling, the geographic locations relative to the mines, and overburden removal scheduling. It is anticipated that this area will be backfilled to an elevation and shape that will promote free drainage to the surrounding surface and graded to blend with the surrounding topography including the reclaimed topography of the ECOSA. Growth medium will be used to cover the overburden placed as backfill. Section 11.2 discusses that approximately six inches of growth medium is expected to be available to cover the reclamation areas. Other material containing fines will be used if stockpiled growth medium is not available. The growth medium will be sampled to determine the need for amendments. Vegetation will be established according to the revegetation procedures presented in Section 11.3. The final reclaimed surface of the East Cresson Mine area will be graded to conform to the runoff patterns discussed previously in Section 5.7.4. A discussion • of diversion/conveyance channels and detention basins for the final backfilled East Cresson Mine area configuration also is provided in Section 5.7.4. 11.4.3 VLF Reclamation of the Phase 5 VLF will occur in a manner similar to that previously approved for Phases I-IV of the VLF. The VLF will be rinsed, the outslopes will be regraded, soil placed, and revegetation performed. Each of these steps is discussed below. Active leaching for gold recovery is expected to be completed approximately eight years after the last ore has been placed on the VLF (approximately 2024). After completion of active leaching, the VLF will be rinsed in the same manner as previously approved. Two rinsing cycles, using recirculated solution and fresh water, will require about 30 months to complete. It is proposed this will be followed by a hydrogen peroxide (H2O2) assisted rinsing cycle to complete removal of cyanide (the need for this H2O2 rinse will be evaluated during VLF rinsing). The financial warranty is based on two standard water rinsing cycles and one H2O2 rinsing cycle over an approximate five-year period. The rinsing • procedure will employ a rinse-rest strategy as previously approved. The VLF will Cripple Creek & Victor Gold Mining Company Cresson Project Mine Life Extension 11-13