Riversdale's Zambezi River Barging Project
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Riversdale’sRiversdale’s Zambezi Zambezi River River BargingBarging Project, Project, Zambezi Zambezi River, River, MozambiqueMozambique FinalEnvironmental Environmental and andSocial Social Impact Impact AssessmentAssessment Report Report August 2011 Delivering sustainable solutions in a more competitive world NON-TECHNICAL SUMMARY INTRODUCTION An Environmental and Social Impact Assessment (ESIA) has been compiled for the proposed Zambezi River Coal Barging Project, on behalf of Riversdale Mozambique Limitada (hereafter referred to as RML). RML is a 65%-owned subsidiary of Riversdale Mining Limited, a mining company listed on the Australian Stock Exchange, with operations in South Africa and Mozambique. The other 35% of RML is owned by Tata Steel, a major Indian steel producer. An ESIA is a systematic process that predicts and evaluates the potential impacts a proposed project may have on aspects of the physical, biological, socio-economic and human environment as determined by specialist studies and analyses of the specific environment. Mitigation measures, as set out in the approved environmental management plan, are then developed and incorporated into the Project execution plan to eliminate, minimise or reduce adverse impacts and, where practicable, to enhance benefits. RML have appointed Environmental Resources Management Southern Africa Pty Ltd (ERM) in partnership with Impacto Associados Lda (Impacto) as the independent consultants to undertake the ESIA for the Zambezi River Coal Barging Project, the main results of which are presented in this non-technical summary. EIA Process The ESIA process followed was designed to comply with the relevant Mozambican environmental legislation. Accordingly, the ESIA process comprised of a number of key steps, namely: • Project Registration • EPDA Phase (also known as Scoping Phase, and culminating in an EPDA Report) • Specialist Studies • Impact Assessment Phase (culminating in an ESIA Report). PROJECT OVERVIEW The Zambezi River Coal Barging Project (the Project) provides one of the means of transporting coal from the Riversdale’s Benga mine in Tete to international markets. The proposed Project begins with the barge coal loading facilities at the point where coal is received from the overland conveyor line from the Benga Mine and ends when the coal is loaded onto ocean-going vessels via a transloader ENVIRONMENTAL RESOURCES MANAGEMENT RIVERSDALE MOZAMBIQUE LIMITADA I located offshore at Chinde. Barging will be undertaken using specially designed shallow draft boats pushing between four and eight unpowered hopper barges, similar to barging operations currently being used on other rivers like the Mississippi River in the United States of America. The Project comprises the following elements (illustrated in Figure.1): • loading coal onto barges to be pushed downriver using pushboats (from the loadout point at Benga to Chinde); • some land based support facilities at the load out point; • initial capital and maintenance dredging in certain locations (about 180km in the approximately 540km stretch of river) to have a navigable channel for barging down the river; • mooring points and fenders (if required) on either side of the Dona Ana Bridge; • mooring points and support facilities at Chinde; and • pullboats (also called shuttle tugs) pulling single barges from the mooring points at Chinde out to a transloader approximately 15km to 20km offshore. ENVIRONMENTAL RESOURCES MANAGEMENT RIVERSDALE MOZAMBIQUE LIMITADA II Figure.1 Locality Map PROJECT DESCRIPTION Construction Phase The construction phase activities consist of capital dredging and the construction of various components of infrastructure along the reaches of the Zambezi River. These are highlighted below. Capital Dredging Capital dredging refers to the initial dredging required to ensure the navigable channel is wide and deep enough to allow the proposed coal barging Project to proceed. Dredging will need to take place at various locations (totalling approximately 180km) along the river from Benga to Chinde, a distance of approximately 540km. The “ideal” channel is one that, when the flow is low, has a minimum depth of 3.0 to 3.5m. The dimensions of the channel have been designed based on recognised guidelines for barge convoy and tugboat movement. Capital dredging within the river would be undertaken by cutter suction dredgers (CSD). This type of dredger is very common and comprises a suction pipe fitted with a cutter head supported below a floating barge, and a discharge pipeline. The dredger is anchored in position in the river and swivels around a rear pivot, sweeping the cutter head and suction pipe in a horizontal arc through the sediment on the river bed. The cutter head is designed to separate and breakdown the sediment to pass through the suction and discharge pipelines to prevent clogging. The dredged material is then disposed of via the discharge pipeline. The figure below illustrates a typical CSD. ENVIRONMENTAL RESOURCES MANAGEMENT RIVERSDALE MOZAMBIQUE LIMITADA IV Figure.2 Diagram of Typical CSD Currently the base case is for dredged material to be deposited alongside the dredged channel (on the side with the greatest distance to the river bank). Mitigation measures proposed by the ESIA team suggest that it would be environmentally desirable (1) to deposit the dredged material in the lees of islands or sand bars wherever possible. This approach has been adopted. It is expected that approximately eight CSDs will be required, distributed along the river. Capital dredging is also required across the bar at the entrance to the Zambezi River at Chinde in order to achieve adequate depth for the barging operation out to the transloading locations. At the entrance bar, the wave conditions are too rough for use of a cutter suction dredger. Here the capital dredging would be performed by a side casting trailer dredger or trailing suction hopper dredger (TSHD). The TSHD is a self propelled ship with an internal hopper. Material is removed from the seabed much like a vacuum cleaner and placed in the hopper of the dredger. The side casting trailer dredger is similar to a TSHD but has no hopper. Accordingly, the side casing trailer does not store the material before disposal but simply pumps it to the side of the vessel back onto the seabed. A typical side casting trailer dredger and TSHD are shown below. (1) Deposition in the lees is may reduce the rate of infill of the navigable channel and may create a bit more braiding, which is a move toward more "natural" conditions, prior to the construction of the Cahora Bassa and Kariba dams. ENVIRONMENTAL RESOURCES MANAGEMENT RIVERSDALE MOZAMBIQUE LIMITADA V Figure.3 Typical Side Casting Trailer Dredger Figure.4 Typical TSHD (material stored on board for disposal at appropriate location) The time period for capital dredging of the entrance bar is expected to require less than two months to complete. All capital dredging operations would take place 24 hours a day, 7 days a week (weather and flow conditions permitting). ENVIRONMENTAL RESOURCES MANAGEMENT RIVERSDALE MOZAMBIQUE LIMITADA VI Construction of River Infrastructure The river infrastructure to support the barging operation comprises mainly the barge loading facilities at the loadout point in Benga, floating repair and maintenance facilities for push boats and barges at Benga ,mooring points upstream and downstream of Dona Ana Bridge, a floating transloader downstream of Dona Ana Bridge, if required fendering at the two bridges (Dona Ana and Caia), and a range of facilities at Chinde; including, mooring points, a floating dry dock, shuttle tug base, and floating transloader. RML is also considering establishing some facilities on land on the north side of the river opposite Chinde for the barging operations. These include: • Administrative and communication office. • Ablution facilities. • Wastewater treatment plant. • Generator. • Fuel storage and fuel dock. • Emergency floating dry dock repair facility. • Heliport • If land on the northern bank is available and proves suitable, equipment storage areas. RML is investigating locating some of the administrative and support facilities in Chinde Town. Operational Phase Barging is planned to be a 24 hour, 7-day a week, year-round operation. This all year operation will however be subject to suitable weather and river conditions. It is expected that convoys in the upper half of the river (above Dona Ana Bridge) will comprise four barges initially, with the number of barges increasing to a maximum of eight once sufficient experience has been gained on the river. Downstream of the Dona Ana Bridge, eight barge convoys will be run. Barge traffic intensity will be low. It is anticipated that the frequency of barges travelling to Chinde will commence at several per week and grow to several per day. When return traffic is taken into account, it is anticipated that the maximum average number of convoys passing a point on the riverbank per day will be seven. This figure includes convoys heading both downstream and upstream. Lighting will be required at all loading, offloading and changeover points. A detailed discussion on the operational activities is presented below. Convoy Assembly Full barges will be towed by assist tugs to mooring points a short distance downstream of the loader. There they will be assembled into convoys of ENVIRONMENTAL RESOURCES MANAGEMENT RIVERSDALE MOZAMBIQUE LIMITADA VII either four or eight barges, depending on river channel conditions at the time, and a push