Supporting Technical Assessments

01 will be decommissioned to allow for the full excavation of the GOP. Excavation will continue in a way that ensures all runoff falls into the pit and is impounded within the pit. Pit water will be captured within the pit and pumped to the Water Treatment Plant. The SRP associated with the Southern Stockpile (SRP-GOP-02) will either be retained for future use during the pit rehabilitation or decommissioned and reconstructed at a later date. Management of this SRP will be confirmed in the SSESCP. 2.4. TSF Conversion and Rehabilitation Approximately 5Mt of rock will be used to partially backfill the pit to prepare it for use as a Tailings Storage Facility (TSF). During the development and operation of the TSF all pit water will continue to be pumped to the Water Treatment Plant. The Southern Stockpile SRP (SRP-GP-02) will be recommissioned for the rehabilitation phase before the stockpile is reworked. Once the stockpile has been exhausted and the area stabilised, the SRP will be decommissioned. 3. EROSION AND SEDIMENT CONTROL DETAILS The erosion and sediment control methodology has been designed in accordance with best practice and the principles outlined in TR2009/02. Specific erosion and sediment control calculations and drawings can be found within the appendices. Appendix A – Erosion and sediment control calculations and typical details. Appendix B – Erosion and sediment control drawings: ESCP-GOP-001-01 ESCP-GOP-001-02 ESCP-GOP-001-03 3.1. Clean Water Diversions It is unlikely that major clean water diversions will be required, due to the nature and location of the work. Perimeter bunding will be used, as required, to divert areas of clean water away from the site. The perimeter bunds will generally be constructed using stripped topsoil and will be stabilised immediately following construction. TR2009/02 recommends that clean water diversions are designed to carry the flow from the 20% annual exceedance probability (AEP) rain event (plus 300mm freeboard). Where possible the clean water diversions have been increased in size to convey the 5% AEP storm event, including a freeboard of 300mm. Perimeter bunds will be a minimum of 600mm high as discussed in Section 3.2.

RkJQdWJsaXNoZXIy MjE2NDg3