KUYASA MINING (PTY) LTD KIPOWER IPP PROJECT INTEGRATED WATER USE LICENSE APPLICATION METHOD STATEMENT WORK IN WETLAND AREAS AND RIVERS

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1 KUYASA MINING (PTY) LTD KIPOWER IPP PROJECT INTEGRATED WATER USE LICENSE APPLICATION METHOD STATEMENT WORK IN WETLAND AREAS AND RIVERS November 2014

2 DOCUMENT APPROVAL RECORD ACTION FUNCTION NAME DATE SIGNATURE Prepared EIA Coordinator P Sewmohan November 2014 Reviewed Technical Review Tolmay Hopkins November 2014 Approved Project Director M van Zyl November 2014

3 KUYASA MINING (PTY) LTD KIPOWER IPP PROJECT INTEGRATED WATER USE LICENSE APPLICATION METHOD STATEMENT WORK IN WETLAND AREAS AND RIVERS CONTENTS PAGE 1. INTRODUCTION Purpose of this document Construction work proposed in wetland areas and over rivers RECOMMENDED METHODOLOGY - CONSTRUCTION OF CONVEYORS IN WETLAND AREAS General design measures Specific design measures Construction measures RECOMMENDED METHODOLOGY CONSTRUCTION OF BRIDGES ACROSS THE WILGE RIVER Ash disposal facility access road bridge Ash conveyor bridge across the Wilge River Construction measures RECOMMENDED METHODOLOGY - CONSTRUCTION OF CLEAN WATER DISCHARGE CANALS AND OUTLET STRUCTURES Design Construction measures... 11

4 3 KUYASA MINING (PTY) LTD KIPOWER IPP PROJECT INTEGRATED WATER USE LICENSE APPLICATION METHOD STATEMENT WORK IN WETLAND AREAS AND RIVERS 1. INTRODUCTION KiPower (Pty) Ltd is a subsidiary of Kuyasa Mining, which also owns Delmas Coal and ikhwezi Colliery. Delmas Coal and ikhwezi Colliery are located approximately 20 km to the south-east of the town of Delmas in the Victor Khanye Municipality, within the Nkangala District Municipality of the Mpumalanga Province of South Africa. The town of Leandra, part of the Gert Sibande District Municipality (Mpumalanga Province), is located to the south-east of the two mines. The town of Devon, part of the Sedibeng Municipality (Gauteng Province) is located to the south-south-west of the two mines. KiPower wishes to establish a new 600 MW power plant in close proximity to Delmas Coal, utilising coal from this mine as the fuel for the power plant. Associated with the power plant would be an ash disposal facility that must also be located in close proximity to the plant. The KiPower Power Plant is a mouth-of-mine power plant, i.e., coal is taken directly to the power plant after processing at Delmas Coal s North Shaft. The ash from the power plant will be disposed of on a new ash disposal facility. The design life of the power plant is planned at 30 years. The proposed Power Plant has to comply with all the applicable environmental authorisations. Independent consultant Ltd (J&W) undertook an integrated Environmental Impact Assessment and Waste License Application and an Integrated Water Use License Application for the project. 1.1 Purpose of this document This document supports the Integrated Water Use License Application, and provides a Method Statement for construction work that will take place in wetland areas and over rivers. 1.2 Construction work proposed in wetland areas and over rivers The categories of construction work that will take place are described below Construction of conveyors in wetland areas Coal will be transported from Delmas Coal on dual conveyors to the power plant stockpile area. Although the conveyor route lies within an existing haul road between Delmas Coal and Ikhwezi Colliery, the conveyor will cross two wetland areas as shown in Figure 1. Limestone will be transported from a rail offloading point to the power plant stockpile area. The determination of this route was constrained by the existing rail system. This conveyor route crosses one wetland area as shown in Figure Construction of bridges over the Wilge River

5 4 Ash will be transported from the power plant to a new ash disposal facility (ADF). This conveyor route crosses the Wilge River, and a new bridge will be built across the Wilge River to support the ash conveyor as well as service pipelines between the power plant and the ADF. The location of the bridge is shown in Figure 1. A new access road to the ADF will be built from a new intersection on the existing D1059 road. The access road also crosses the Wilge River and a new road bridge will be built across the Wilge River for this purpose as shown in Figure Construction of clean water discharge canals and outlet structures Clean storm water diverted around the power plant and the ADF will discharge into the local environment and into the Wilge River via concrete or gravel channels and outlet structures.

6 5 Figure 1: Location of wetland crossings and river crossings

7 6 2. RECOMMENDED METHODOLOGY - CONSTRUCTION OF CONVEYORS IN WETLAND AREAS 2.1 General design measures The preliminary design of the conveyor system was done in accordance with CEMA (6th edition). The following general requirements are included in the preliminary design of the conveyors: Conveyors are designed with a belt turn-over system. This minimises spills outside of the transfer areas. In addition, all overland conveyors are covered so as to prevent direct rainfall from landing on the material being conveyed, i.e. coal or sorbent. Rainfall runoff from overland conveyors is therefore regarded as clean in terms of their impact on surface water. Surface runoff at transfer points will be locally contained by means of bund walls linked to silt traps. Silt traps with drying pads will be provided at all transfer points. Transfer points will be enclosed and fitted with dust suppression systems to minimise dust pollution. Conveyors at river crossings will be fully enclosed. Conveyors are fitted with HDPE idlers to minimise noise. An overall width of 8 m for single conveyors and 20 m for dual conveyors has been allowed for. This makes provision for the conveyors and associated service roads. The service roads will have gravel surfacing. The conveyors have generally been located above the natural ground level (i.e. on fill) and along the alignment of existing roads, where possible. 2.2 Specific design measures The following measures will be implemented to minimise the impact of the overland conveyor crossings on the wetlands: No transfer points, loading points or discharge points are located within wetlands. General pollution control measures (See Section 2.1) will minimise the risk of pollution from the overland conveyors. The conveyor support formation will be constructed to be in fill. Permeable fill (i.e. rock fill) will be placed at the base of the formation to allow the seepage of groundwater from up gradient to down gradient areas. For service roads across wetland areas, culverts will be placed at regular intervals (maximum spacing of approximately 50 m) to allow the through flow of surface runoff. 2.3 Construction measures The following measures will be implemented prior to construction of the conveyors in wetland areas: Remove the upper layer of wetland soils (organic alluvium) and stockpile locally. The purpose of removing the clay layer is to ensure that the crossing can be rehabilitated more effectively after construction is completed.

8 7 Place rockfill material over the construction area to facilitate movement of labour and construction vehicles. Place a layer of compacted gravel on the rockfill layer to provide a surface for movement of labour and construction vehicles. The following measures will be implemented after construction is complete in wetland areas: Remove the compacted gravel layer for re-use in other areas of the project. If not required for re-use, then dispose of according the site waste management plan. Remove rockfill layer for re-use in other areas of the project. If not required for reuse, then dispose of according the site waste management plan. Replace the wetland soils that were removed prior to construction. Stabilise the soils with Maccaferri BioJute where required by the Site Environmental Control Officer.

9 8 3. RECOMMENDED METHODOLOGY CONSTRUCTION OF BRIDGES ACROSS THE WILGE RIVER 3.1 Ash disposal facility access road bridge The ash disposal facility is located on the opposite side of the Wilge River to the power plant. A road bridge over the Wilge River is therefore required to gain access to the ash disposal facility from the power plant Bridge design The proposed design solution for the road bridge is summarised below: Superstructure: The proposed superstructure consists of precast, pre-tensioned beams with a continuously reinforced cast in-situ slab on top. The pre-cast beams can be placed across the river without the need for constructing temporary support (scaffolding) across the stream to support the concrete during construction. Bearing plates are provided at abutments and piers to accommodate thermal expansion. Substructure & foundations: The bridge can be supported on either normal spread footings or piles, depending on the actual rock depth at the abutment and pier positions. Piles are generally preferred if there is a potential for undermining due to scour, i.e. if shallow rock does not exist. The substructure has been aligned with the river flow direction to minimise the impact on the stream flow. Approach slabs will be provided at bridge abutments to ensure a gradual transition from the road to the bridge. The bridge has been designed to accommodate a 1:100 year return period flood event, with a suitable provision for freeboard, as dictated by the vertical alignment of the road. 3.2 Ash conveyor bridge across the Wilge River The ash conveyor bridge over the Wilge River will comprise of a 45 m long (3 x 15m spans) fully enclosed steel bridge. This bridge will also be used to support various pipelines related to KiPower s water management system Bridge Design The proposed design solution for the ash conveyor bridge is summarised below: Superstructure: The superstructure will consist of lattice steel girders with a cast in-situ concrete slab. The conveyor will be bolted to the slab and enclosed on the top and sides with IBR cladding to prevent dust pollution from, and rainfall onto, the conveyor. A concrete kerb edge will be provided on the sides of the concrete slab to prevent spilled material from entering the river or adjacent areas. Substructure & foundations: The bridge will be supported on either normal spread footings or piles, depending on the actual rock depth at the abutment and pier positions. Piles are generally preferred if there is a potential for undermining due to scour, i.e. if shallow rock does not exist. The piers have been aligned perpendicular to the bridge (at an angle of approximately 20 degrees to the river flow direction). The bridge has been designed to accommodate the

10 9 1:100 year return period flood event, with a suitable freeboard as dictated by the vertical alignment of the conveyor. 3.3 Construction measures The following measures will be implemented prior to construction: Remove top 300mm of soil from the river bed and stockpiled locally, offstream. This work will be done using hand held implements and labour. Place gabion mattresses filled with non-carbonaceous stone and provided with lifting hooks in the river bed area to facilitate movement of labour and equipment. Provide a temporary flow channel within the work area to allow river flow. This can be created using gabion mattresses covered with plastic lining or geotextile layer. Place geotextile layer or similar separation layer on the gabion mattress where labour and equipment movement is required. Place a layer of compacted gravel on the geotextile separation layer to provide a surface for movement of labour and construction vehicles. The following measures will be implemented after construction of the bridges: The gravel layer will be removed for re-use in other areas of construction. The geotextile layer will be removed for re-use and/or disposal according to the construction waste management plan. The Gabion mattresses will be removed from the river bed. The soil layer will be replaced in the river bed and natural flow conditions will be reestablished.

11 10 4. RECOMMENDED METHODOLOGY - CONSTRUCTION OF CLEAN WATER DISCHARGE CANALS AND OUTLET STRUCTURES 4.1 Design Clean surface runoff collected from the power plant and ADF areas will be discharged in a controlled manner to prevent erosion downstream of the discharge point. At the power plant this will be done by constructing energy dissipating outlet structures, and/or discharging directly into existing streams. Clean runoff from the ADF will be contained in flood attenuation dams, from where it will be discharged at a reduced flow rate. All discharge points have been designed to accommodate the 1:50 year storm event. The design for the outlet structure is shown in Figure 2 and Figure 3. Figure 2: Typical detail for Clean Water Outlet Structure Figure 3: Erosion protection on Clean Water Outlet Structure

12 Construction measures The following measures will be implemented prior to construction: Remove the upper layer of soils (organic alluvium) and stockpile locally. Place rockfill material over the construction area to facilitate movement of labour and construction vehicles. Place a layer of compacted gravel on the rockfill layer to provide a surface for movement of labour and construction vehicles. The following measures will be implemented after construction is complete: Remove the compacted gravel layer for re-use in other areas of the project. If not required for re-use, then dispose of according the site waste management plan. Remove rockfill layer for re-use in other areas of the project. If not required for reuse, then dispose of according the site waste management plan. Replace the wetland soils that were removed prior to construction. Stabilise the exposed soils with Maccaferri BioJute where required by the Site Environmental Control Officer. P Sewmohan EAP Coordinator Tolmay Hopkins Technical Review Marius van Zyl Project Director For Jones & Wagener 19 November 2014 Document source: C:\Users\psewmohan\Documents\Projects\Jones & Wagener\KiPower IPP\IWULA\FINAL IWULA\REPORT\C182_KiPowerIWULA_CrossingsMethodStatement.docx Document template: Normal.dotm

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