B-6 – Area 6 – Assessment of Environmental Effects 32 Draft SSESCPs for each project Area (including Area 6). In accordance with accepted best practice, it is intended that OGNZL will provide final SSESCPs for each project area for certification by the Consent Authority following detailed design but prior to commencing any earthworks onsite. The principles of the WRC Technical Report No. 2009/02 Erosion and Sediment Control Guidelines for Soil Disturbing Activities, January 2009 (TR2009/02) have been adopted by Southern Skies (2022) for the design, construction, maintenance and decommissioning of erosion and sediment control measures. However, as a result of the scale and nature of the works proposed, Southern Skies (2022) identify that deviations from that standard will be required to achieve the outcomes sought by the ESCAR. The deviations will be provided in SSESCPs and by implementing those deviations Southern Skies (2022) identify that the works will achieve the same or better outcome than a TR2009/02 compliant approach. By way of summary the erosion and sediment control measures will include: Installation of silt fences on steep slopes where possible; Construction of temporary clean and dirty water diversion drains; Construction of sediment retention ponds; and Use of flocculants. 3.3 NORTHERN ROCK STACK CONSTRUCTION The NRS will be constructed to 173 m RL with 7.0 M m3 capacity leaving the conveyor corridor and loadout station in place. The NRS will incorporate similar design features as the existing TSFs to restrict the potential for the generation of acid leachate, and for leachate to enter groundwater. These features include: A low permeability, earthfill liner beneath the rock stack. Sub-surface seepage drains to intercept any seepage. Leachate collection drains. Capping to minimise oxygen ingress. The construction of the NRS will likely be undertaken in stages as the requirement for rock storage volume develops. Initially the working areas of the NRS will consist of converting the existing non-acid forming (“NAF”) Northern Stockpile into a potentially acid forming (“PAF”) stockpile. This will require constructing a Zone A liner and leachate drains and utilising the existing
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