3 Alternatives. 3.1 Introduction

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1 3 Alternatives 3.1 Introduction This chapter provides a description of alternatives considered for the Simandou Port. It outlines how potential social and environment impacts were considered and provides justification for selected alternatives. This chapter focuses on the alternatives where social and environment outcomes are a determining factor in selecting the preferred alternative. The remainder of this chapter is structured as follows: Section 3.2: Port Locations to the North or to the South of Conakry; Section 3.3: Port Locations to the South of Conakry; Section 3.4: Ile Kaback and Morebaya Alternatives; Section 3.5: Dredged Material Disposal; and Section 3.6: Summary Project Development Phases Rio Tinto s project development processes follow a similar pathway for all Projects, beginning with a concept and ending with a robustly demonstrated business case. The development of a study follows a logical sequence and is intended to allow a business case to be made between projects and between options within a project. Each stage of the study varies in complexity, duration, effort and cost, and is also dependent on the nature of the project. The key project phases for the Simandou Project are illustrated in Figure 3.1 below. Figure 3.1 Key Project Phases for the Simandou Project Stage Gates Key decision points between stages in the Project lifecycle. The duration of each stage varies according to the work required, but typically study duration and detail increases with progression of the project. The dominant theme throughout these development phases is reducing uncertainty and risk. At all phases social and environment considerations form an integral part of 3-1

2 the study. Surveys are initiated, preliminary impact and risk assessments conducted, and the overall knowledge base becomes increasingly detailed and is used to inform analysis of alternatives. A key element of this project development approach is the stage-gating process. Stage-gating is used in order to clearly define the scope, ensure key deliverables have been completed and the risk profile is satisfactorily understood. Technical and business evaluations are linked to the stage-gate process and the outcomes of these evaluations inform funding decisions Analysis of Alternatives The analysis of alternatives takes into account a range of factors with varying criteria depending on the option being assessed. Examples include health, safety, social, and environment; technical risk; capital and operating costs; operability; construction schedule; and geo-political risk. Typically, the selected alternative represents a compromise or balanced outcome as it is unlikely that all criteria for all factors can be simultaneously maximised and in fact maximising one factor may come at the expense of another. However, it is important to note that for the factors identified as determinants in the selection of an option, minimum criteria are understood and still achieved for each of those factors. The analysis of alternatives is therefore iterative and represents interplay of potentially competing demands Alternatives Considered The alternatives considered in the assessment of the port Project are summarised as follows: locations to the north or to the south of Conakry; different locations to the south of Conakry; locations and placement of components within the Ile Kaback and Morebaya area; and locations for the disposal of dredged material. Each of these project elements and the alternatives is presented below with a summary of the key social and environmental impacts taken into consideration when evaluating the options prior to identifying the preferred solution. 3.2 Port Locations to the North or to the South of Conakry A number of potential port locations along the Guinean coast were considered during the course of planning for the Simandou Project. Locations were chosen based on their proximity to existing port facilities or to deep water offshore, which resulted in a number of locations that can be coarsely divided by their location either to the north or to the south of Conakry. The potential port locations to the north of Conakry were Cap Verga and Ile Binari, while the options to the south of Conakry included the Kaback area, a site on Tana Island (Pointe Yélitono) and three sites closer to the border with Sierra Leone. The approximate locations of these potential options to the north of south of Conakry are illustrated in Figure 3.2. The two locations that were considered to the north of Conakry are in the vicinity of Guinea s largest existing port at Kamsar, which, for these options, would act to some extent as an offloading facility at the start of the Project. Both northern options had small terrestrial footprints (around 250 ha) with onshore facilities located close to shore, and required dredging of an access channel of up to 5 km in length. Ile Binari required a jetty of around 3.5 km, whereas the jetty considered for Cap Verga was around 25 km in length. In comparison to those options south of Conakry the northern ports options required an additional 200 to 230 km of railway, increasing the combined port and rail footprint by ha to between and ha. 3-2

3 10 0'0"N 9 0'0"N Légende: Région de l'île Kaback / Ile Kaback Area 15 0'0"W '0"W Emplacement alternatif du port / Alternative Port Location Agglomération / Settlement Chef lieu de préfecture / Prefecture Chief Town Chef lieu de sous-préfecture / Sub-Prefecture Chief Town Limite de la sous-préfecture / Sub-Prefecture Boundary Ile Binari Cap Verga KAMSAR BINTIMODIA MANKOUNTAN TOUGNIFILI C O L I A DOUPROU BOFFA-CENTRE Boffa '0"W Ile Kaback Pointe Yelitono Pointe Gbessy Bellansang L I S S O FRIA-CENTRE TORMELIN TAMITA TANÉNÉ 14 0'0"W KO B A Salatougou BANGUIGNY SOGOLON BAGUINET K O L L E T Baguinet-Centre B A D I OUASSOU K H O R I R A Conakry RATOMA MATOTO T O N D O N KAKOSSA Badi G U I N E A FALÉSSADÉ SAMAYAH KOURIA MAMBIA SINTA B A N G O U Y A H KINDIA-CE NTRE DAMAKANIA Friguiagbé Molota Centre Mambia Centre FRIGUIAGBÉ WONKIFONG SIKHOUROU Maférinyah Sikhourou MAFÉRINYA ALLASSOYAH Allassoya MOUSSAYA Forécariah Moussayah K A L I A H FARMORÉAH Benty B E N T Y 13 0'0"W SANGARÉAH Bangouya Centre Farmoréah 13 0'0"W Client: Taille: Titre: A4 Figure 3.2 Projection: WGS 1984 UTM Zone kilomètres Kindia MOLOTA KOLEN TÉ MADINA-OULA Madina-Oula S i e r r a L e o n e KOBA SOUGUÉTA Kolente Souguéta Emplacements des options alternatives pour le port de Simandou / Locations of Alternative Options for the Simandou Port Date: 19/09/2012 Dessiné par: WB Vérifié par: AM Approuvé par: KR Projet: '0"N 9 0'0"N Echelle: Comme Barre d échelle File: SimandouGIS_IG_CK\Maps\ERM\Alternatives\Port\Option_A\po_A_Alt_Locations.mxd

4 Although the overall length of railway was smaller, the footprints for the port components for the southern options were generally larger eg the Ile Kaback option was around 600 ha, almost double that of those to the north of Conakry. Overall however, the total Project footprints of the southern port options would be much smaller than the northern options when taking into consideration the associated rail alignments. For example, the route for the Ile Kaback port option would result in an estimated combined port and rail footprint of around ha. Offshore, long jetties and access channels would be a necessity at several of the locations south of Conakry due to the greater distances to the required water depths for marine operations. Poor ground conditions close to the coast would require the stockyard and other onshore facilities to be constructed further inland and connected to port components at the coast by overland conveyor systems of many kilometres. A high level analysis of alternatives was conducted to assess the key social and environmental considerations for the port options to the north and south of Conakry. The port options north of Conakry were found to have lower social sensitivity than the southern options as their surrounding areas are relatively less populated. Conversely, the environmental sensitivity of the northern options was found to be generally greater than the southern options. Sensitivities included the presence of the Rio Kapatchez Ramsar site an important bird area located around the estuary to the south of Ile Binari and higher value habitats, such as mangroves and turtle nesting beaches. Although potentially more sensitive, due to the smaller footprints of the actual port sites, the northern options were expected to have a lower degree of interaction with sensitive environmental receptors and therefore a lower environmental impact would be expected than for the southern options. The northern port locations were found to have lower sensitivity when considered alone. However, when the footprint of their rail alignments was also taken into account both the social and environmental sensitivity and potential impacts were greatly increased. A northern alignment would have resulted in a higher number of river and road crossings, the need for additional surveys to be conducted along the rail route, a longer duration of rail construction and the resettlement of the higher number of people impacted. After consideration of the environmental and social constraints of the whole Project, the northern port options were rejected due to the increased size of the overall Project footprint, including within sensitive areas, when compared with the southern port options. As a result the port options to the south of Conakry were considered further in the initial analysis of alternatives. 3.3 Port Locations to the South of Conakry A number of alternative potential port locations were identified to the south of Conakry. The options considered included the Ile Kaback area, Pointe Yélitono and three sites closer to the border with Sierra Leone (Pointe de Gbessy, Salatougou and Pointe Bellangsang) (see Figure 3.2). At this stage of the analysis all of the port options south of Conakry included supporting infrastructure consisting of an overland conveyor running for some distance from the stockyard to a marine (jetty) conveyor, connecting to an export wharf in deeper water. This offshore export wharf connected to the shore by a jetty was considered to be the desirable solution to minimise long term maintenance dredging of the port access channel given the high levels of sedimentation in the coastal area. A location on the Tana Island peninsula at Pointe Yélitono was considered as it could make use of the natural topography existing at the south west corner of the island. An access channel to the site is provided by the Melacorée River, making this site the closest location south of Conakry with natural access to deep water close to land. While this would reduce the expected volumes to be dredged during construction, the high rates of sedimentation in the river would likely require a high level of maintenance dredging during operation. In addition, the Pointe Yélitono site is entirely covered by mangroves and the underlying ground conditions have poor properties for construction and low bearing capacity. The proposed port infrastructure included a service wharf situated close to land, with onshore components either at the coast or located around 15 km further inland. In both cases extensive ground improvement would be required to connect facilities at the coast to the mainland, over large areas of mangrove and floodplain. The filling or reclamation of some low lying land or shallow submerged areas at the mouths of the Tana and Melacorée Rivers would also be necessary. 3-4

5 Pointe de Gbessy, Salatougou and Pointe Bellangsang, the three potential sites lying closer to the border with Sierra Leone are located on the southern bank of the Melacorée River. In common with Tana Island, an access channel is provided by the Melacorée River. This would reduce the need for dredging during construction, although the access channel would need to be extended in the case of Salatougou and high levels of maintenance dredging would be required during operation. These southern locations have better ground conditions than at Tana Island, but are still largely situated in low lying coastal plains or mangrove areas, overlying marine deposits with poor geotechnical properties for the proposed site use. Offshore conditions at the southernmost locations are also challenging, with currents and local conditions combining with a risk of bad weather and storms to present potential technical difficulties for both construction and port operation. The initial design considered for a port in the Kaback area consisted of an offshore deep water export wharf, connected by marine (jetty) and overland conveyors to the stockyard and railhead yard further. The original export wharf connected to the shore at Matakang Island which lies at the south west of Ile Kaback. Ground conditions in the area are more favourable, as the north-eastern portion of Kaback consists mainly of loose ferralitic soil with good bearing capacity which would require little structural improvement work. However, for an export wharf offshore of Matakang a long jetty would be required, as the distance to deeper water offshore is greater than for the other options south of Conakry, which benefit from a natural deep water access channel. The Pointe Yélitono option had high environmental sensitivity, due to the presence of undisturbed mangrove and a potential designated area: the Melacorée River may be designated in the future as a Marine Protected Area, while its social sensitivity is fairly low. Although the presence of a natural access channel is an engineering advantage, the technical challenges presented by this option would increase both construction and operation costs for the Project. In particular, technical challenges relate to: flooding and drainage at the low-lying site; the possibility of ground subsidence; and the volume of infill required for large areas either onshore or offshore in the vicinity of the Tana and Melacorée River s estuaries for the placement of infrastructure and facilities. As such the option at Pointe Yélitono was rejected. The three port options closer to the Sierra Leone border and the Ile Kaback option had similar levels of both social and environmental sensitivity. Both areas are densely populated and have high agricultural importance, and construction would result in similar levels of displacement of people and loss of land, with slight variations depending on the specific site and configuration. Environmental sensitivities for both areas relate to the presence of habitats with higher biodiversity value. Given the similarities in these sites the analysis of alternatives did not produce a favoured option. The Kaback area presented fewer potential challenges with regard to transboundary issues, social and environmental impacts and was therefore preferable in securing project delivery to schedule and budget. The Kaback area also offered better ground conditions, lower rates of sedimentation in the marine construction area and less challenging offshore conditions. 3.4 Ile Kaback and Morebaya Alternatives Following the selection of the Kaback area as the preferred location for the port development a Preliminary Engineering Assessment (PEA) undertaken in December 2011 appraised alternative locations for an iron ore export wharf for the Simandou Project. As part of the appraisal process, alternative locations were considered against factors which influence operations for an iron ore business and a multi-facility Port capable of importing and exporting multiple commodities. The PEA narrowed down a preferred location in the area of the Ile Kaback peninsula. As part of the studies process, a refinement of considerations for location and general arrangement of Port assets resulted in two alternative concepts: a multi-commodity Port located in the Morebaya River versus a single commodity (iron ore) export wharf located offshore of Matakang Island. Figure 3.3 illustrates four conceptualised options for the port located on Ile Kaback and in the Morebaya River. Detailed consideration was given to the location of the stockyard (derived from an analysis of the location of the railway), Marine Offloading Facility (MOF), the export wharf and requirements for conveyors, the underlying ground conditions and flood risk potential and the environmental and social constraints related 3-5

6 to all of these factors. The stockyard option for the port in the vicinity of the MOF was selected due to the relatively stable ground, low population density and because the area should not subject to tidal inundation. The stockyard location for the other possible port options was selected for proximity to the rail loop and car dumpers. These concepts were tested to look for an optimised range against key parameters of delivery schedule, capital and operating costs, whilst meeting health and safety best practice and minimising the impact on the local population and natural environment. The resulting conclusions and recommendations to the project Steering Committee represented an assessment of efficiency in design that focused also on avoidance of large proportions of population and minimising the project footprint in sensitive environmental areas and communities Matakang and Matakang Angled The Matakang option was the base case used for most of the earlier evaluations discussed in Sections 3.2 and 3.3. It was proposed that this would include a port and export wharf located off the Matakang peninsula at the south-western end of Ile Kaback, connected to the stockyard and rail loop further inland by a long overland conveyor belt spanning the length of Ile Kaback. The Matakang Angled variation has the same onshore layout, with the export wharf arranged slightly further to the north-west with a longer access channel coming further inshore. There would be considerable capital expenditure and engineering challenges associated with the long offshore jetty and dredging and a requirement for on-going maintenance dredging, particularly for the angled option. These designs also presented social and environmental challenges in the marine environment related to the introduction of a large new structure to Matakang island which may have affected localised water flow, sediment transport and erosion. In addition the jetty may have prevented access along the shore and restricted movement of vessels in the nearshore environment which would have affected the large local fishing community. The length and complexity of the onshore conveyor required for these options would have resulted in high capital expenditure due to the number of rivers crossed and the need to avoid several settlements and stretches of agricultural land. In common with other overland conveyor configurations, there are also challenges in terms of health and safety for these options associated with the potential for injury to people during construction and operation of the conveyor. For both the Matakang options a straight alignment of the onshore conveyor was considered, as well as a dog legged alternative alignment designed to minimise loss of mangrove, productive agricultural land and proximity to settlements Morebaya River A Morebaya River option presented the significant advantage of a port co-located with the MOF utilising an export wharf arranged along the east bank of the Morebaya River south of the MOF quay. A short overland conveyor running through the MOF site would connect the export wharf to the stockyard and another short overland conveyor would connect the stockyard to the rail loop east of the road to Touguiyiré. This option would require a high level of both capital and maintenance dredging due to the need for a longer access channel to be created and maintained within the river itself and in inshore location. The total volume removed by capital dredging for this option has been estimated at around 140 Mm 3, compared to around 74 Mm 3 for the Matakang options. From an engineering and programme perspective it would reduce the need for construction of an offshore jetty which would be a costly and complex exercise and associated risk. This option would also result in more inshore vessel movements, due to the additional distance to be travelled to the port and increased dredger activity. On-going maintenance dredging would represent a significant long term cost expenditure and dredging and the dredge plume and vessel traffic in the river and inshore waters would increase the amount of interaction with the local fishery in comparison to an offshore jetty and export wharf. 3-6

7 13 30'0"W 13 25'0"W 13 20'0"W '0"N 9 25'0"N Fleuve Morebaya / Morebaya River '0"N 9 20'0"N Embouchure du Fleuve / River Mouth 9 15'0"N Matakang S S ee nn ee gg aa ll M M aa ll ii G Guuiinn eeaa-- BBiiss ssaauu G G uu ii nn ee aa LL ii bb ee rr ii aa '0"W Légende: '0"W 13 20'0"W Client: Taille: A4 Emplacement du quai d'exportation / Export Wharf Location Chenal de navigation / Shipping Channel Mesure des infrastructures à terre / Extent of Onshore Infrastructure Agglomération / Settlement Chef lieu de préfecture / Prefecture Chief Town Chef lieu de sous-préfecture / Sub-Prefecture Chief Town Village / Village CCoottee dd' 'IIvvooi irree 9 10'0"N 9 10'0"N S S ii ee rr rr aa LL ee oo nn ee 0 1 kilomètres Titre: Figure 3.3 Comparaison des options alternatives de l'ile Kaback pour le port de Simandou / Comparison of Ile Kaback Alternative Options for the Simandou Port Route secondaire / Secondary Road Route tertiaire / Tertiary Route Projection: WGS 1984 UTM Zone 29N Date: 19/09/2012 Vérifié par: OF Projet: Dessiné par: WB Approuvé par: KR Echelle: Comme barre d'échelle File: SimandouGIS_IG_CK\Maps\ERM\Alternatives\Port\Option_A\po_A_Alt_Kaback_Locations.mxd 9 15'0"N Matakang oblique / Matakang Angled

8 However this option represented a significant change to the Matakang Island option, where the car dumper, stockyard, and wharf have been consolidated to a location near the east bank of the Morebaya River, colocated with the Marine Offloading Facility. This preferred location would require an increase in construction dredging above the estimated volume identified for the Matakang Island option. Optimising the dredging length, width and depth are central to mitigating the potential impacts to communities and the marine environment. The port would load Cape size vessels of up to DWT. The Morebaya River option has the potential to be expandable in the future beyond 95Mtpa. The engineering, community and environmental benefits resulting from the proposed Morebaya River location would include capital savings in direct, field and indirect costs, a reduction in footprint size and a reduction in the severance of communities and overall land-take. The socio-economic benefits would also be expected to demonstrate measurable improvements in comparison to previous options. The berths (and associated facilities) identified in this option would be supported by infrastructure networks and administrative systems to be established for the Simandou Port. Expandability could also be introduced in stages without affecting Simandou production. This compares favourably to the Matakang Island option design given the wharf and jetty are one-off structures that need to be designed and built with the maximum expandable tonnage initially as alterations to load bearing strengths and piling sizes cannot be altered at a later date, and therefore additional costs would be incurred up front as part of the Project River Mouth An alternative option consisting of a port location on Ile Kaback just south of the mouth of the Morebaya River was also considered. The resulting configuration would involve the main onshore components of the port such as the stockyard being located at the rail loop. An overland conveyor would connect the stockyard and rail loop located inland with some additional onshore developments such as surge bins on the coast of Ile Kaback. The conveyor would then go offshore via a 10 km jetty structure to an export wharf; a dredged channel to waters of sufficient depth would complete the project. This option would require a greater capital expenditure and increased health and safety challenges associated with the overland conveyor, offshore jetty and export wharf than for the Morebaya River option, although not to the same extent as for the Matakang options. Whilst vessel and dredge plume interactions with local water users would be reduced by this option, in common with the Matakang Options there would be increased interaction with water flow, sediment transport, and potential restrictions on access and movements of vessels such as local fishing boats. Table 3.1 presents the key social and environmental considerations for the port options in the Kaback- Morebaya Area. 3-8

9 Table 3.1 Social and Environmental Analysis of Alternative Kaback Area Locations Topic Area Matakang and Matakang Angled Morebaya River River Mouth Social Environment Matakang is densely populated and there is a high concentration of villages and hamlets on the western side of Ile Kaback. The conveyor crosses three densely populated roads and settlements; there would be interaction with coastal communities due to construction of the jetty and export wharf. The western side of Ile Kaback supports a high concentration of important agricultural land used for rice growing. The overland conveyor alignment would result in loss of mangroves and impacts on the local hydrographic network. There would be a lower risk of long term impacts on marine habitats and fauna due to reduced level of dredging but disturbance would still occur under the jetty footprint during construction. The area is relatively densely populated and used for agriculture, but impacts will be minimised due to short conveyor and use of the already developed MOF site. The short conveyor crosses only one road with minimal severance of vehicular access. High levels of dredging will result in greater interaction with local marine traffic and artisanal fishery. Short conveyor with minimal impacts on local hydrographic network and mangroves. Risk of impact from high levels of dredging on fish habitats and fishing activities. Potential for saline intrusion into Morebaya River and tributaries due to dredging of access channel. High concentration of villages and hamlets on Ile Kaback, with associated communal resources and infrastructure. The conveyor crosses four densely populated roads and settlements; onshore infrastructure could require relocation of communities. This area of Ile Kaback supports a high concentration of important agricultural land used for rice growing. The overland conveyor alignment would result in loss of mangroves and some impacts on the local hydrographic network. Lower risk of impacts on marine habitats and fauna due to reduced level of dredging but disturbance would still occur under the jetty footprint during construction. 3-9

10 After analysis of the overall programme, engineering and financial implications of the different options and in considering the key social and environmental constraints presented in Table 3.1 the Morebaya River option was found to be the preferred option. It is acknowledged that this option may have relatively high long term operation costs due to the requirement for on-going maintenance dredging. The Ile Matakang, Matakang Angled and Morebaya River Mouth options have therefore not been taken forward for further development. The Morebaya River option will result in lower levels of social impact onshore than the other options, as minimal new land area will be occupied or affected for construction and operation of the port. The short overland conveyors in particular will result in a low level of severance to communities and a low level of impact on local habitats and on the drainage network in the area. There will be on-going social and environmental challenges in the marine environment associated with the high level of dredging required for this option. However, impacts on terrestrial biodiversity, hydrology and high value land uses will be much reduced as compared to the other Kaback Area options considered. The Morebaya River option presents fewer and less significant potential social and environmental impacts principally due to the reduced port footprint and reduced length of onshore conveyor. This option has been found to result in a considerable improvement of the Project s risk profile. The more compact port configuration will be less complex to build and there will be less reliance upon specialist resources associated with construction of a long overland conveyor. The main port components will also be located close to the MOF and associated specialist cargo handling facilities and therefore there is a greater opportunity with this option for offsite fabrication of Project components. Opportunities for procurement of re-fabricated modules and components offers a range of benefits including quality control, access to specialist construction and manufacture offsite and as a result should benefit the project schedule and delivery. The choice of the Morebaya River option is further supported by an assessment that examined the costs and benefits associated with transforming the MOF into a permanent MOF and incorporating it into the port. This study concluded that converting to a permanent facility would be an effective way to maximise early investment during the Project. In summary consolidating all of the port components on the Morebaya River, in the vicinity of the MOF, is considered to be the most favourable configuration for the Simandou Port in terms of potential social and environmental impacts, schedule risk and maximising early investment during the Project. 3.5 Dredged Material Disposal Large quantities of dredged material will be removed during the course of the Project, through both capital and maintenance dredging. The method and location of dredge disposal is important in ensuring that not only social and environmental impacts are kept to a minimum, but also that the disposal site presents no hazard to other marine users. Preliminary options analysis identified ten options for disposal: unconfined deep water disposal offshore; unconfined nearshore disposal; unconfined thin layer disposal offshore; semi-confined deep water disposal in natural troughs or placement between sub-aqueous berms; beach nourishment; intertidal recharge; formation of islands, land reclamation; confined disposal on river bank; confined disposal onshore; and confined disposal into redundant borrow pits or other onshore depressions. Some of these options have similar social and environmental impacts associated with them, and so have been grouped together within the following table. Chapter 3: Aternatives 3-10

11 Table 3.2 Social and Environmental Analysis of Alternative Dredged Material Disposal Locations Topic Area Unconfined Disposal (Land / Sea) Confined Disposal on Land Confined / Semi-Confined in Coastal and Intertidal Area Social Interference with fishing activities as a result of increased turbidity and impacts on marine fauna. Risk to humans from spread of contaminated sediments should they exist. Confined disposal on land, especially to the shore and river bank, is associated with serious social impacts on communities. Minimal interference with fishing activities. Potential need for resettlement & compensation. This disposal type can be used beneficially for intertidal recharge. Minimal impacts on people, as there will be limited interference with fishing activities and fish stocks and it will not require resettlement. Confined / Semi-Confined in Deep Water Minimal impacts on people, as there will be limited interference with fishing activities and fish stocks and does not require resettlement. Problems associated with odour and visual impacts. Environment Extensive areas of increased turbidity, leading to widespread smothering and loss of seabed, coastal and terrestrial habitat. Increased mortality, displacement and changes to composition of fauna. Potential changes to coastal processes. Risk to wildlife and of water pollution from spread of contaminated sediments should they exist. Confined disposal on land, especially to the shore and river bank, is associated with serious environmental impacts to sensitive coastal and terrestrial habitats and fauna (eg mangroves). Risks may be associated with the high salinity levels in dredged sediments. Impacts on marine habitats and fauna minimised. Minimal impacts on the wider ecosystem, as increased suspended sediment has less impact in already turbid areas. May be some loss of intertidal habitat, including fish nursery areas, and mortality, displacement or changes to the composition of intertidal and marine fauna. Potential changes to coastal processes. Semi-confined deep-water disposal minimises impacts on benthic fauna, although some localised impacts will occur due to increased sedimentation. No other species are likely to be affected, and in particular high value fauna such as turtles and manatees are unlikely to experience impacts. 3-11

12 Land disposal of dredged materials would require a high level of additional control measures to be put in place to prevent undesirable impacts. These would include containment, dewatering and the control of runoff water to enable settlement of solids and to improve water quality before it is discharged and potentially soil washing and desalinisation. Dewatering and consolidation are time consuming, often requiring several months, meaning that fill operations need to be spaced out or many locations used. Given the volumes of sediment involved, especially in the initial capital dredge, this may not be feasible and the footprint required for this work may have addition environmental and social impacts. Intertidal recharge has relatively little environmental and social impact, and may even be beneficial, however this option would be unlikely to be able to accommodate the large volumes of material that will be generated under the scheme and is therefore not feasible. As a result, semi-confined deep-water disposal has subsequently been taken forward as the preferred dredge spoil disposal option. This option has the lowest level of environmental and social impact of all those considered, while presenting an effective way of disposing of the dredged material likely to be produced by the Project. 3.6 Summary The Project has considered a number of options and alternatives during each stage of study development, before agreeing on the preferred scope of the port Project. Through a process of defining an increasingly specific geographical area and the consideration of other design elements, as presented in this chapter, a preferred option was taken forward to form the port Project design used for the impact assessment. The preferred option as assessed by this SEIA is described in detail in Chapter 2: Project Description. The decision on the port option and dredged sediment disposal option was based on the following key factors: engineering, economic and geographical or transboundary considerations; alignment with the preferred route for the rail; the preference for proximity to deep water off-shore, so as to minimise dredging costs; local bathymetry, hydrology and sedimentology; the suitability of ground conditions at the site population density and the importance of agricultural usage of land in the area; and the presence of high value and sensitive habitats. The resulting port option on the Morebaya River will consist of the port being co-located with Marine Offloading Facility. The MOF is an export wharf on the east bank of the Morebaya River which will already have been constructed to facilitate development of the wider Simandou Project. The port will include a short overland conveyor from the car dumper to the stockyard and another short overland to the export wharf. A dredged access channel will be created within the Morebaya River and running out to natural waters of sufficient depth offshore. An offshore location for semi-confined disposal of dredged material will be located beyond the 20m water depth isobath south of the main dredge channel and additional disposal site will be identified as required though out the life of the project. 3-12