- Email: [email protected]
Hamma Water Desalination Plant: planning and funding
Desalination 203 (2007) 107–118
Hamma Water Desalination Plant: planning and funding Chris Mooij Metoc plc, Exchange House, Liphook, Hants GU30 7DW, United Kingdom Tel. +44 (1428) 727800; Fax +44 (1428) 727122; email: [email protected]
Received 10 May 2006; accepted 16 May 2006
Abstract Algeria has a 1200 km coastline on the southern rim of the Mediterranean, which offers great potential for the desalination of seawater to supply much needed drinking water. The Hamma Desalination Plant, situated near Algiers, is the largest desalination plant in Africa. It will supply up to 200,000 m3/d of essential potable water to the Algiers area. This $200 million dollar Build–Own–Operate plant was required to meet both the legislative requirements of the Algerian Government and the Overseas Private Investment Corporation’s (OPIC) Environmental Procedures — underpinned by World Bank Guidelines. In consequence, detailed environmental assessments were required. Metoc was selected by the Hamma Water Desalination Company to undertake the studies and obtain approval for the plant. The plant is an excellent example of good site selection (infrastructure availability, use of reclaimed land); environmental impact assessment and mitigation (delivery against established procedures, clear identification of issues and mitigation procedures); and understanding of engineering and operational risk (recirculation of hypersaline discharges, consideration of external pollution sources). This paper is set against a backdrop of gaining planning approval and funding for the Hamma Water Desalination Plant. The focus of the paper is to draw attention to three features of the work that were of note, either because they were examples of good practice in action, or because they had the potential to bring, commercial benefit to the project. These were the areas of site selection, methodology development and environmental modelling. The purpose of the paper is to share this experience as it may be of material benefit to the desalination community in its future developments. Keywords: Hamma Water Desalination Plant; Planning; Funding
Presented at EuroMed 2006 conference on Desalination Strategies in South Mediterranean Countries: Cooperation between Mediterranean Countries of Europe and the Southern Rim of the Mediterranean. Sponsored by the European Desalination Society and the University of Montpellier II, Montpellier, France, 21–25 May 2006. 0011-9164/07/$– See front matter © 2007 Published by Elsevier B.V. doi:10.1016/j.desal.2006.05.006
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1. Introduction This paper is set against a backdrop of gaining planning approval and funding for the Hamma Water Desalination (HWD) Plant. The focus of the paper is to draw attention to three features of the work that were of note: either because they were examples of good practice in action, or because they had the potential to bring commercial benefit to the project. The purpose of the paper is to share this experience as it may be of material benefit to the desalination community in its future developments. The first area of note is in the site selection, which was able to harmonise the requirements of the local community, government, economic development and environmental management. It is a good example of how a carefully selected site can meet multiple objectives, which more often than not, are in conflict. The second area of note is the development of a single linear methodology that met planning and funding application needs at a local and international level. The subsequent reporting and audit process was smooth, such that issues raised by the various stakeholders readily incorporated. This had a material impact on minimising project timescales and project costs. The third area of note is in the use of screening models for simple initial environmental assessment (i.e. matching the model to the task) and the potential use of Environmental Design Optimisation (EDO) to fully understand the environmental and recirculation risks. This would have allowed the developer to fully understand not only the risks of plant to the environment but also the risks of the environment to the plant (e.g. the use of highly polluted source water). The process would then have allowed the developer to optimise the intake and outfall arrangements to deliver both a capital (i.e. construction) benefit and an operational benefit (i.e. minimise the unit cost of produced water). Table 1 summarises these project features.
Table 1 Project feature highlights Feature
Benefit
Site selection
The coming together of political, social, economic and environmental objectives Improved communications, smoother work programme and reporting, reduced project timescales and reduced project costs Reduce CAPEX and OPEX
Methodology
Use of “smart” modelling
2. Background In recent years Algeria has suffered from increasing pressure on its freshwater resources due to a variety of factors including; increasing drought conditions through a lack of rainfall; and increasing demand through industrial and population growth, particularly in the northern coastal zone. This has led to increased exploitation of the groundwater resources, which in turn has led to problems of contaminant pollution of important aquifers and more frequent instances of saline intrusion. Algeria has a 1200 km northern coastline that borders the Mediterranean Sea. It offers a high potential for desalination of sea water to supply the necessary drinking water to meet the demands of the coastal cities and towns. The Hamma Water Desalination (HWD) plant was scheduled for completion in December 2007 and is the largest desalination plant in Africa. The plant was designed to draw 500,000 m3/d, from which 200,000 m3/d of potable water is generated using a reverse osmosis process. This was fed to the Algiers distribution network. The remaining 300,000 m3/d comprised reject water and wastewater from cleaning processes. This was collected in an outfall basin where it was neutralised. From the basin, wastewater overflows by
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gravity into the outfall pipeline to a submerged discharge point and discharged at a salinity of approximately double that of ambient seawater. The construction period was scheduled for 24 months, which left only 4 months for the Environmental Impact Assessment (EIA) required to support the planning application and application for funding. Also within this time scale an Environmental Monitoring and Management Plan (EMMP) was developed. 3. Site selection 3.1. Geography Figs. 1 and 2 show the site area within the surrounding area of Algiers. The site was surrounded by a major motorway to the south, the coastline on the northern boundary, with industrial facilities such as a gas transfer station to the east and the main port area to the west. The general area was in a state of disuse and it is believed that parts of the proposed site were once used as ‘pleasure gardens’ (Figs. 3 and 4). The area was very dilapidated with concrete and brickwork crumbling and remaining shrubs and trees unkempt. The land itself was reclaimed by dumping rock on the shoreline to support the construction of the motorways and the pleasure gardens. 3.2. Potable water needs The political and social needs for further reliable supplies of water of potable quality were established. They were based on the increasing population of the City of Algiers, the increasing demand for clean water, the low annual rainfall, the cross-contamination of existing groundwater resources, and the incidence of coastal saline intrusion. Economically, the site was ideally situated because it was close to the point of use of the water and would make best use of the local infrastructure in terms of its locality to the road access, the water distribution network and the power grid. There
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was also opportunity to support local economic development through employment and in the provision of the resource required to support such development. The site also had the advantage of being central for local labour, which could use the existing public transport network, and was well-placed to use local contractors, plant and equipment. From an environmental perspective, the immediate coastline offered no amenity value in terms of scenic aspects, leisure, nor were there occurrences of wildlife habitats, feeding, or breeding grounds. Furthermore, was not possible to enjoy views by the sea or the shore. Therefore, it was considered that a well-designed desalination plant, shielded by flowers and trees, would be a positive benefit. The use of reclaimed land and ‘brown field’* site had advantages from a sustainability perspective and the environmental assessment did not identify any ecological or archaeological issues in the terrestrial or marine environments, which may have affected the project. The plant discharge is to a marine area of limited biological value, where a saline discharge was likely to have no significant environmental impact. It was concluded that whilst there are environmental challenges, the mitigation of such will improve the environmental quality of area overall. This brought a clear convergence of the political, social, economic and environmental objectives. 3.3. Location There were two further proposed desalination plants on the east and west headlands of the Bay of Algiers, some 25–30 km from the city centre.
The term ‘brownfield site’ refers to land that is or was occupied by a permanent structure, which has become vacant, underused or derelict and has the potential for redevelopment.
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Fig. 1. Geographic overview.
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Fig. 2. Site layout and local infrastructure map.
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Fig. 3. View of the centre of the site looking east.
Fig. 4. View of the disused ‘Pleasure Gardens’ at the west of the site.
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It was considered that another plant close to these locations, together with new supply pipelines, would cause significant disruption to residential and agricultural areas, and would detract from the scenic and leisure value of Mediterranean coast. As previously stated it was preferable to reuse a brown-field site rather than seek a green-field site. Also, the location was close to the city’s infrastructure and, the area was suitable in environmental terms. 3.4. Water source Algeria has no permanent rivers, and no inland lakes (except for salt lakes at a great distance from the city) which might have provided a water source. Thus it was concluded that seawater was the only feasible resource. Although it was recognised that the enclosed nature of the bay may result in increased pollution levels, the cost of pre-treatment was outweighed by the advantages of proximity to the existing city power grid, the availability of a brown-field site, and proximity to the existing water distribution network.
Fig. 5. View of sewer crossing the existing site.
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3.5. Process The two main processes for desalinating seawater are thermal evaporation and reverse osmosis. The reverse osmosis (membrane) process is considered overall to have the lesser energy demand per unit of product water, to have the lesser use of chemicals, and the lesser volume of atmospheric emissions. The performance of the membranes has been fully proven in installations world-wide, and it is also more robust in handling variations in raw seawater quality. The site location and the process selected were considered to be optimal from the point of view of environmental impacts and socio-economic benefits. 3.6. Seawater quality The desalination site was located adjacent to the eastern side of the Port of Algiers. This part of the bay is exposed to various sources of pollution in particular those generated by the activity of the port and wastewater outfalls which flow directly into the sea at El Hamma.
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After consultation with local authorities, it was planned to collect and treat storm water within the port, and to construct a sewage treatment plant near El Harrach. An immediate problem on local contamination was that of a main sewer that crosses the site (Fig. 5). After consultation with the Hydraulic Department of Wilaya D’Alger, it was agreed that this sewer was to be disabled and diverted to a local pumping station connected to the treatment plant in Koubem, thus eliminating this potential issue. 4. Methodology The developed methodology had to serve two purposes. Firstly, it needed to address the planning requirements and secondly to meet the needs for loan approval of the international finance institutions, such as the Overseas Private Investment Corporation (OPIC) and the World Bank. 4.1. Algerian legislation Environmental Impact Assessment (EIA) was introduced to Algerian legislation by Law 83-03 [1], in 1983, which established the initial framework, with the objectives of assessing and making people aware of the direct and indirect impacts of development projects on ecological balances, the environment and quality of life. Actual implementation of the legislation is by way of Decree 90-78 [2], in 1990, which requires an EIA for any activity that may directly or indirectly affect the environment, public health, agriculture, natural areas, fauna, flora or historic monuments and sites. Several other laws and Decrees were also of relevance covering areas such as air emissions, noise and vibration [3], regulation on water resources [4], regulations on liquid waste [5] and project sustainability [6]. 4.2. Algerian regulatory authorities The following departments were consulted in support of development applications.
4.2.1. The Ministry of Environment and Regional Development The Ministry of the Environment secures compliance with the legislation and regulations in force concerning environmental impact assessments for development, capital and infrastructure projects. It also secures compliance with the enforcement of the technical regulation and standards linked to development planning and the environment. 4.2.2. Ministry of Health and Population The Ministry of Health and Population is responsible for enforcement of the regulations and recommendations described in Law 85-05 [7], on health protection and promotion, and in Law 8807, on hygiene, safety and occupational medicine. Enforcement of the provisions of Law 88-07 [8] is assigned to the Labour Inspectorate in recognition of its expertise in this area. 4.2.3. Ministry of Culture The Ministry of Culture is responsible for the management of protected cultural and archaeological sites. The operational aspect of this responsibility is carried out by the National Agency for Archaeology and Protection of Historical Monuments and Sites. 4.2.4. Local authorities The local authority (Wilaya) is responsible for water resources, development planning, agricultural service, forestry, health and population, urban development and habitat construction. All Environmental Impact Assessment Reports in support of planning applications are first submitted to the Wilaya, which then forwards copies to the other authorities, according to the requirements of Decree No. 90-78 [2]. The local authority with responsibility for the proposed Hamma Desalination Plant project is the Wilaya d’Alger. Recently a law was introduced, Law No. 02-02,
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2002, which refers to the protection of the coastal fringe [9]. Through the consultation process it was understood that the HWD project was exempt from the provisions of this law due to the requirement for a ready supply of fresh water [10].
4.3. OPIC The OPIC requirements for project funding approval are included in the OPIC Environmental Handbook, February 2004 [11]11. They are the result of efforts to progressively harmonise the standards and procedures of the major international funding organisations, to facilitate co-financing arrangements, so making it simpler for clients to address the necessary environmental considerations. OPIC has adopted the World Bank Group guidelines and standards as the foundation for its own procedures. Like the World Bank, OPIC screens all applications according to the following procedure. In the first stage OPIC determines whether its support of a project would violate “Categorical Prohibitions”. The HWD plant pasted this stage. In the second stage of screening OPIC determined the level of effort and public disclosure and consultation required. Dependent on its potential environmental and social severity, the HWD plant would be categorised as A, B or C: • Category A projects require a full EIA Report, as well as an Environmental Management and Monitoring Plan (EMMP). Guidance on the expected contents of these documents is given in Appendices B and C of the OPIC Environmental Handbook and Appendix E provides a fairly comprehensive list of industries and sites likely to be placed in this category. • Category B projects are those likely to have adverse impacts that are less significant than those of Category A projects, meaning that few if any of the impacts are likely to be irreversible: they are site specific; and mitigation measures can be designed more readily than for Category A projects. They normally require
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a limited EIA and a Mitigation Plan, which is incorporated into the project. • Category C projects do not have material impacts on the environment and do not require an EIA. Through this review process, OPIC establishes the project standards and mitigation conditions necessary for funding support. These conditions are then discussed with the applicant and included in the loan agreement. OPIC monitors compliance with these contractual conditions throughout the term of the agreement. Desalination is not included in the OPIC Category A listing of industrial developments and the “World Bank Pollution Prevention and Abatement Handbook” [12]12 has no industry-specific guidelines for this type of operation. The issue faced was that the HWD plant did fall into Category A but there was a risk that a Category B assessment would be insufficient. Had this occurred there would have been consequential impacts on the project time scales and costs. To minimise this risk a bespoke methodology was developed that had elements of Category A and elements of Category B. Additionally, it included the requirements of Algerian legislation. Because the methodology was bespoke it was subject to final screening by OPIC after the submission of the Environment Report. It was thus important to strike a balance between the project constraints and ensuring the methodology was sufficiently robust. 4.4. World Bank In the absence of OPIC guidance, the World Bank Guidelines were referred to. The World Bank guidelines are implemented using The Pollution Prevention and Abatement Handbook, which has general and industry-specific guidelines, including numerical limits for pollutant emissions. Also the World Bank requirements for an EIA are set out in World Bank Operation Policy OP 4.01.
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Various guidelines were available. However, these were general in nature and some did not fit well with a desalination plant development. For example, guidelines for noise emissions were directly relevant, whereas guidelines for liquid waste were non-industry specific, and therefore many were not applicable to a desalination plant discharge, where the discharge is direct to the marine (seawater) environment. Similarly, no emission standards were specified solely for desalination plant processes. However, air emissions from any plant process are evaluated on a case by case basis. Whilst, the General Environmental Guidelines do provide specific emissions guidelines, these are normally applied to plants that produce significant emissions such as power stations. Such guidance again supported the development of a bespoke methodology, underpinned by careful consultation to ensure the areas covered and level of detail were appropriate. 4.5. Harmonisation of guidelines The challenge for the HWD plant was to harmonise the requirements of Algerian, OPIC and World Bank guidelines such that they could be addressed through a single assessment and included in a single report. The report would then be used in support of both the planning and funding applications. Finally, the work was to be completed in a time scale of 4 months. For these reasons, a lot of emphasis was put on the development of the methodology. In particular, communications with various stakeholders were frequent, thorough and relevant. This enabled the methodology to evolve as particular issues become more, or less, relevant. Also of importance, was the experience gained in other industries of developing bespoke methodologies (e.g. oil and gas, water, marine cables). This enabled a deeper understanding of the various guidelines, which in turn helped to “get it right the first time”. Through the blending of Algerian, Category A and Category B requirements to the right level of detail the following areas were investigated.
• • • • • • • • • • • • • • •
Landscape and topography Meteorology and climatology Oceanography Water quality and contamination Air quality Noise Geology, soil composition and ground water quality Marine dredging, spoil dumping and disposal areas Ecology Cultural, wrecks and archaeological issues Infrastructure Visual impact Military activities Fisheries Socio-economic issues
Numerous issues were identified during the EIA process. These were either mitigated directly or included in the Environmental Monitoring and Management Plan (EMMP). The EIA and EMMP were delivered on time and budget to the various stakeholders. Further close liaison was maintained during the review process, with Mott MacDonald acting as OPIC’s environmental auditors. 5. Smart modelling 5.1. Required screening modelling Screening modelling was required as part of the planning and funding applications. Whilst such modelling was entirely fit for purpose, it did not exploit the full value that modelling could have brought to the applications. Screening models were used for the following: • Initial assessment of environmental impact due to the hyper-saline discharge • An estimate of the potential for re-circulation • The effects of trenching the intake and discharge pipes • The environmental impacts of discharging process sludge.
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An oceanographic and water quality assessment of the coastal waters was undertaken as part of the environmental assessment. Care was taken to ensure that the assessment identified, or collected, data necessary for the modelling assessment. Key considerations from the oceanographic and water quality assessment were: • The effect of the coastal Algerian current • Residual currents • Weak tidal effects in the locality • The impact and frequency of storms • Temperature and salinity • Water quality • Sediment transport • Water pollution sources The principal concern in terms of marine water quality was the discharge of the hyper-saline effluent from the plant. A first order modelling tool developed by Metoc, termed QUICK-PLUME was used to estimate the potential impact of the hyper-saline discharge. Modelling was based on the predicted operational characteristics of the plant, hydrodynamic data and experience of similar studies in other locations. The modelling conservatively identified potential environmental risk together with measures that could be taken to minimise this risk. A second model developed United States Environment Protection Agency (USEPA), termed Visual Plumes was used to examine the near-field and mid-field behaviour of: disturbed sediments due to trenching of the intake and discharge pipes and; the dispersion of suspended solids associated with discharge of process sludge. It was determined that suspended solids would rapidly return towards background levels and thus process sludge could be discharged on this basis rather than land filling of sludge. The screening assessment tools met the requirements of the environmental assessment and satisfied the auditors of the project. They also assessed risk and, where appropriate, were used to identify practical solutions.
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5.2. Potential added value from environmental design optimisation It was not considered necessary to develop complex numerical models of the coastal waters for the initial screening. This would go beyond the requirements, add to cost and put pressure on tight time scales. However, there was a further consideration that was not taken up as part of the planning and funding application but could have assisted this phase of the project. It was the use of Environmental Design Optimisation (EDO). EDO is a process developed by Metoc that critically examines the operational and environmental variables such that the optimal length, discharge position and diffuser arrangement of the outfall are identified with reference to a similarly optimum intake arrangement. In this case optimal refers to the arrangement that meets the environmental and operational (e.g. minimising re-circulation risk) constraints at the lowest capital and operational cost. In particular EDO would have enabled the developers to fully understand not only the HWD plant’s impact on the environment but also the impact of the environment on the plant. In effect, EDO would have enabled the developer to identify the intake and outfall arrangement that optimises the following: • Minimise capital costs of outfall and intake pipes • Minimise risk of re-circulation • Fully understand the current and future sources of pollution and how they impact the source water • Understand the implications, and if possible design, to minimise pre-treatment costs The overall output from the EDO would have been to minimise the capital cost and the unit cost of produced water. Whilst it was seriously considered as part of the planning and funding application it was identified as a value added component of the work
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phase rather then a requirement of the environmental assessment. However, it is argued that the output from EDO has a place in both the planning and funding applications. Further, the information is important to the design and construction contractor because it better defines their scope of work. 6. Conclusions The use of reclaimed land and a brown-field site is a good option for the plant development. It was recognised that whilst there are environmental challenges, the mitigation of these will generally improve the environmental quality of area overall. This brings a clear convergence of the political, social, economic and environmental objectives. The methodology was developed to serve multiple needs. These included the requirements of various authorities at local and international level together with the requirements of both planning and funding agencies. The methodology took care to harmonise the various requirements and ensure thorough communications. It is concluded that the approach significantly helped to minimise project time scales and cost. The use of screening models was entirely appropriate for planning and funding requirements. It addressed the key issues and identified solutions without the need for detailed model development that would have compromised the project phase.
However, it is argued that Environmental Design Optimisation (EDO) at this project phase would have brought value to the project and would have better informed subsequent project phases.
References [1] Algerian Law No. 83-03 of 5 February 1983 on environmental protection. [2] Decree No. 90-78 — Decree on environment impact assessment. [3] Decree No. 93-184 — Decree on regulating noise emissions which reinforces Article 121 of Law 8303. [4] Algerian law No. 83-17 — relating to the water code. [5] Decree No. 93-160 — Regulating discharges of industrial liquid effluents. [6] Algerian Law No. 03-10 — Relating to environmental protection within the framework of sustainable development. [7] Algerian Law No. 85-05 — On the protection and promotion of health. [8] Algerian Law No. 88-07 — Relating to occupational hygiene and safety. [9] Law No. 02-02 du 5 février 2002 relative à la protection et à la valorisation du littoral. [10] Meeting between Wilaya D’Alger, HWD & Metoc plc on 03/08/04 in Algiers. [11] OPIC Environmental Handbook February 2004, available through http://www.opic.gov/Publications/ envbook_2004.htm. [12] World Bank Pollution Prevention and Abatement Handbook.
Hamma Water Desalination Plant: planning and funding Chris Mooij Metoc plc, Exchange House, Liphook, Hants GU30 7DW, United Kingdom Tel. +44 (1428) 727800; Fax +44 (1428) 727122; email: [email protected]
Received 10 May 2006; accepted 16 May 2006
Abstract Algeria has a 1200 km coastline on the southern rim of the Mediterranean, which offers great potential for the desalination of seawater to supply much needed drinking water. The Hamma Desalination Plant, situated near Algiers, is the largest desalination plant in Africa. It will supply up to 200,000 m3/d of essential potable water to the Algiers area. This $200 million dollar Build–Own–Operate plant was required to meet both the legislative requirements of the Algerian Government and the Overseas Private Investment Corporation’s (OPIC) Environmental Procedures — underpinned by World Bank Guidelines. In consequence, detailed environmental assessments were required. Metoc was selected by the Hamma Water Desalination Company to undertake the studies and obtain approval for the plant. The plant is an excellent example of good site selection (infrastructure availability, use of reclaimed land); environmental impact assessment and mitigation (delivery against established procedures, clear identification of issues and mitigation procedures); and understanding of engineering and operational risk (recirculation of hypersaline discharges, consideration of external pollution sources). This paper is set against a backdrop of gaining planning approval and funding for the Hamma Water Desalination Plant. The focus of the paper is to draw attention to three features of the work that were of note, either because they were examples of good practice in action, or because they had the potential to bring, commercial benefit to the project. These were the areas of site selection, methodology development and environmental modelling. The purpose of the paper is to share this experience as it may be of material benefit to the desalination community in its future developments. Keywords: Hamma Water Desalination Plant; Planning; Funding
Presented at EuroMed 2006 conference on Desalination Strategies in South Mediterranean Countries: Cooperation between Mediterranean Countries of Europe and the Southern Rim of the Mediterranean. Sponsored by the European Desalination Society and the University of Montpellier II, Montpellier, France, 21–25 May 2006. 0011-9164/07/$– See front matter © 2007 Published by Elsevier B.V. doi:10.1016/j.desal.2006.05.006
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1. Introduction This paper is set against a backdrop of gaining planning approval and funding for the Hamma Water Desalination (HWD) Plant. The focus of the paper is to draw attention to three features of the work that were of note: either because they were examples of good practice in action, or because they had the potential to bring commercial benefit to the project. The purpose of the paper is to share this experience as it may be of material benefit to the desalination community in its future developments. The first area of note is in the site selection, which was able to harmonise the requirements of the local community, government, economic development and environmental management. It is a good example of how a carefully selected site can meet multiple objectives, which more often than not, are in conflict. The second area of note is the development of a single linear methodology that met planning and funding application needs at a local and international level. The subsequent reporting and audit process was smooth, such that issues raised by the various stakeholders readily incorporated. This had a material impact on minimising project timescales and project costs. The third area of note is in the use of screening models for simple initial environmental assessment (i.e. matching the model to the task) and the potential use of Environmental Design Optimisation (EDO) to fully understand the environmental and recirculation risks. This would have allowed the developer to fully understand not only the risks of plant to the environment but also the risks of the environment to the plant (e.g. the use of highly polluted source water). The process would then have allowed the developer to optimise the intake and outfall arrangements to deliver both a capital (i.e. construction) benefit and an operational benefit (i.e. minimise the unit cost of produced water). Table 1 summarises these project features.
Table 1 Project feature highlights Feature
Benefit
Site selection
The coming together of political, social, economic and environmental objectives Improved communications, smoother work programme and reporting, reduced project timescales and reduced project costs Reduce CAPEX and OPEX
Methodology
Use of “smart” modelling
2. Background In recent years Algeria has suffered from increasing pressure on its freshwater resources due to a variety of factors including; increasing drought conditions through a lack of rainfall; and increasing demand through industrial and population growth, particularly in the northern coastal zone. This has led to increased exploitation of the groundwater resources, which in turn has led to problems of contaminant pollution of important aquifers and more frequent instances of saline intrusion. Algeria has a 1200 km northern coastline that borders the Mediterranean Sea. It offers a high potential for desalination of sea water to supply the necessary drinking water to meet the demands of the coastal cities and towns. The Hamma Water Desalination (HWD) plant was scheduled for completion in December 2007 and is the largest desalination plant in Africa. The plant was designed to draw 500,000 m3/d, from which 200,000 m3/d of potable water is generated using a reverse osmosis process. This was fed to the Algiers distribution network. The remaining 300,000 m3/d comprised reject water and wastewater from cleaning processes. This was collected in an outfall basin where it was neutralised. From the basin, wastewater overflows by
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gravity into the outfall pipeline to a submerged discharge point and discharged at a salinity of approximately double that of ambient seawater. The construction period was scheduled for 24 months, which left only 4 months for the Environmental Impact Assessment (EIA) required to support the planning application and application for funding. Also within this time scale an Environmental Monitoring and Management Plan (EMMP) was developed. 3. Site selection 3.1. Geography Figs. 1 and 2 show the site area within the surrounding area of Algiers. The site was surrounded by a major motorway to the south, the coastline on the northern boundary, with industrial facilities such as a gas transfer station to the east and the main port area to the west. The general area was in a state of disuse and it is believed that parts of the proposed site were once used as ‘pleasure gardens’ (Figs. 3 and 4). The area was very dilapidated with concrete and brickwork crumbling and remaining shrubs and trees unkempt. The land itself was reclaimed by dumping rock on the shoreline to support the construction of the motorways and the pleasure gardens. 3.2. Potable water needs The political and social needs for further reliable supplies of water of potable quality were established. They were based on the increasing population of the City of Algiers, the increasing demand for clean water, the low annual rainfall, the cross-contamination of existing groundwater resources, and the incidence of coastal saline intrusion. Economically, the site was ideally situated because it was close to the point of use of the water and would make best use of the local infrastructure in terms of its locality to the road access, the water distribution network and the power grid. There
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was also opportunity to support local economic development through employment and in the provision of the resource required to support such development. The site also had the advantage of being central for local labour, which could use the existing public transport network, and was well-placed to use local contractors, plant and equipment. From an environmental perspective, the immediate coastline offered no amenity value in terms of scenic aspects, leisure, nor were there occurrences of wildlife habitats, feeding, or breeding grounds. Furthermore, was not possible to enjoy views by the sea or the shore. Therefore, it was considered that a well-designed desalination plant, shielded by flowers and trees, would be a positive benefit. The use of reclaimed land and ‘brown field’* site had advantages from a sustainability perspective and the environmental assessment did not identify any ecological or archaeological issues in the terrestrial or marine environments, which may have affected the project. The plant discharge is to a marine area of limited biological value, where a saline discharge was likely to have no significant environmental impact. It was concluded that whilst there are environmental challenges, the mitigation of such will improve the environmental quality of area overall. This brought a clear convergence of the political, social, economic and environmental objectives. 3.3. Location There were two further proposed desalination plants on the east and west headlands of the Bay of Algiers, some 25–30 km from the city centre.
The term ‘brownfield site’ refers to land that is or was occupied by a permanent structure, which has become vacant, underused or derelict and has the potential for redevelopment.
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Fig. 1. Geographic overview.
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Fig. 2. Site layout and local infrastructure map.
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Fig. 3. View of the centre of the site looking east.
Fig. 4. View of the disused ‘Pleasure Gardens’ at the west of the site.
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It was considered that another plant close to these locations, together with new supply pipelines, would cause significant disruption to residential and agricultural areas, and would detract from the scenic and leisure value of Mediterranean coast. As previously stated it was preferable to reuse a brown-field site rather than seek a green-field site. Also, the location was close to the city’s infrastructure and, the area was suitable in environmental terms. 3.4. Water source Algeria has no permanent rivers, and no inland lakes (except for salt lakes at a great distance from the city) which might have provided a water source. Thus it was concluded that seawater was the only feasible resource. Although it was recognised that the enclosed nature of the bay may result in increased pollution levels, the cost of pre-treatment was outweighed by the advantages of proximity to the existing city power grid, the availability of a brown-field site, and proximity to the existing water distribution network.
Fig. 5. View of sewer crossing the existing site.
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3.5. Process The two main processes for desalinating seawater are thermal evaporation and reverse osmosis. The reverse osmosis (membrane) process is considered overall to have the lesser energy demand per unit of product water, to have the lesser use of chemicals, and the lesser volume of atmospheric emissions. The performance of the membranes has been fully proven in installations world-wide, and it is also more robust in handling variations in raw seawater quality. The site location and the process selected were considered to be optimal from the point of view of environmental impacts and socio-economic benefits. 3.6. Seawater quality The desalination site was located adjacent to the eastern side of the Port of Algiers. This part of the bay is exposed to various sources of pollution in particular those generated by the activity of the port and wastewater outfalls which flow directly into the sea at El Hamma.
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After consultation with local authorities, it was planned to collect and treat storm water within the port, and to construct a sewage treatment plant near El Harrach. An immediate problem on local contamination was that of a main sewer that crosses the site (Fig. 5). After consultation with the Hydraulic Department of Wilaya D’Alger, it was agreed that this sewer was to be disabled and diverted to a local pumping station connected to the treatment plant in Koubem, thus eliminating this potential issue. 4. Methodology The developed methodology had to serve two purposes. Firstly, it needed to address the planning requirements and secondly to meet the needs for loan approval of the international finance institutions, such as the Overseas Private Investment Corporation (OPIC) and the World Bank. 4.1. Algerian legislation Environmental Impact Assessment (EIA) was introduced to Algerian legislation by Law 83-03 [1], in 1983, which established the initial framework, with the objectives of assessing and making people aware of the direct and indirect impacts of development projects on ecological balances, the environment and quality of life. Actual implementation of the legislation is by way of Decree 90-78 [2], in 1990, which requires an EIA for any activity that may directly or indirectly affect the environment, public health, agriculture, natural areas, fauna, flora or historic monuments and sites. Several other laws and Decrees were also of relevance covering areas such as air emissions, noise and vibration [3], regulation on water resources [4], regulations on liquid waste [5] and project sustainability [6]. 4.2. Algerian regulatory authorities The following departments were consulted in support of development applications.
4.2.1. The Ministry of Environment and Regional Development The Ministry of the Environment secures compliance with the legislation and regulations in force concerning environmental impact assessments for development, capital and infrastructure projects. It also secures compliance with the enforcement of the technical regulation and standards linked to development planning and the environment. 4.2.2. Ministry of Health and Population The Ministry of Health and Population is responsible for enforcement of the regulations and recommendations described in Law 85-05 [7], on health protection and promotion, and in Law 8807, on hygiene, safety and occupational medicine. Enforcement of the provisions of Law 88-07 [8] is assigned to the Labour Inspectorate in recognition of its expertise in this area. 4.2.3. Ministry of Culture The Ministry of Culture is responsible for the management of protected cultural and archaeological sites. The operational aspect of this responsibility is carried out by the National Agency for Archaeology and Protection of Historical Monuments and Sites. 4.2.4. Local authorities The local authority (Wilaya) is responsible for water resources, development planning, agricultural service, forestry, health and population, urban development and habitat construction. All Environmental Impact Assessment Reports in support of planning applications are first submitted to the Wilaya, which then forwards copies to the other authorities, according to the requirements of Decree No. 90-78 [2]. The local authority with responsibility for the proposed Hamma Desalination Plant project is the Wilaya d’Alger. Recently a law was introduced, Law No. 02-02,
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2002, which refers to the protection of the coastal fringe [9]. Through the consultation process it was understood that the HWD project was exempt from the provisions of this law due to the requirement for a ready supply of fresh water [10].
4.3. OPIC The OPIC requirements for project funding approval are included in the OPIC Environmental Handbook, February 2004 [11]11. They are the result of efforts to progressively harmonise the standards and procedures of the major international funding organisations, to facilitate co-financing arrangements, so making it simpler for clients to address the necessary environmental considerations. OPIC has adopted the World Bank Group guidelines and standards as the foundation for its own procedures. Like the World Bank, OPIC screens all applications according to the following procedure. In the first stage OPIC determines whether its support of a project would violate “Categorical Prohibitions”. The HWD plant pasted this stage. In the second stage of screening OPIC determined the level of effort and public disclosure and consultation required. Dependent on its potential environmental and social severity, the HWD plant would be categorised as A, B or C: • Category A projects require a full EIA Report, as well as an Environmental Management and Monitoring Plan (EMMP). Guidance on the expected contents of these documents is given in Appendices B and C of the OPIC Environmental Handbook and Appendix E provides a fairly comprehensive list of industries and sites likely to be placed in this category. • Category B projects are those likely to have adverse impacts that are less significant than those of Category A projects, meaning that few if any of the impacts are likely to be irreversible: they are site specific; and mitigation measures can be designed more readily than for Category A projects. They normally require
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a limited EIA and a Mitigation Plan, which is incorporated into the project. • Category C projects do not have material impacts on the environment and do not require an EIA. Through this review process, OPIC establishes the project standards and mitigation conditions necessary for funding support. These conditions are then discussed with the applicant and included in the loan agreement. OPIC monitors compliance with these contractual conditions throughout the term of the agreement. Desalination is not included in the OPIC Category A listing of industrial developments and the “World Bank Pollution Prevention and Abatement Handbook” [12]12 has no industry-specific guidelines for this type of operation. The issue faced was that the HWD plant did fall into Category A but there was a risk that a Category B assessment would be insufficient. Had this occurred there would have been consequential impacts on the project time scales and costs. To minimise this risk a bespoke methodology was developed that had elements of Category A and elements of Category B. Additionally, it included the requirements of Algerian legislation. Because the methodology was bespoke it was subject to final screening by OPIC after the submission of the Environment Report. It was thus important to strike a balance between the project constraints and ensuring the methodology was sufficiently robust. 4.4. World Bank In the absence of OPIC guidance, the World Bank Guidelines were referred to. The World Bank guidelines are implemented using The Pollution Prevention and Abatement Handbook, which has general and industry-specific guidelines, including numerical limits for pollutant emissions. Also the World Bank requirements for an EIA are set out in World Bank Operation Policy OP 4.01.
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Various guidelines were available. However, these were general in nature and some did not fit well with a desalination plant development. For example, guidelines for noise emissions were directly relevant, whereas guidelines for liquid waste were non-industry specific, and therefore many were not applicable to a desalination plant discharge, where the discharge is direct to the marine (seawater) environment. Similarly, no emission standards were specified solely for desalination plant processes. However, air emissions from any plant process are evaluated on a case by case basis. Whilst, the General Environmental Guidelines do provide specific emissions guidelines, these are normally applied to plants that produce significant emissions such as power stations. Such guidance again supported the development of a bespoke methodology, underpinned by careful consultation to ensure the areas covered and level of detail were appropriate. 4.5. Harmonisation of guidelines The challenge for the HWD plant was to harmonise the requirements of Algerian, OPIC and World Bank guidelines such that they could be addressed through a single assessment and included in a single report. The report would then be used in support of both the planning and funding applications. Finally, the work was to be completed in a time scale of 4 months. For these reasons, a lot of emphasis was put on the development of the methodology. In particular, communications with various stakeholders were frequent, thorough and relevant. This enabled the methodology to evolve as particular issues become more, or less, relevant. Also of importance, was the experience gained in other industries of developing bespoke methodologies (e.g. oil and gas, water, marine cables). This enabled a deeper understanding of the various guidelines, which in turn helped to “get it right the first time”. Through the blending of Algerian, Category A and Category B requirements to the right level of detail the following areas were investigated.
• • • • • • • • • • • • • • •
Landscape and topography Meteorology and climatology Oceanography Water quality and contamination Air quality Noise Geology, soil composition and ground water quality Marine dredging, spoil dumping and disposal areas Ecology Cultural, wrecks and archaeological issues Infrastructure Visual impact Military activities Fisheries Socio-economic issues
Numerous issues were identified during the EIA process. These were either mitigated directly or included in the Environmental Monitoring and Management Plan (EMMP). The EIA and EMMP were delivered on time and budget to the various stakeholders. Further close liaison was maintained during the review process, with Mott MacDonald acting as OPIC’s environmental auditors. 5. Smart modelling 5.1. Required screening modelling Screening modelling was required as part of the planning and funding applications. Whilst such modelling was entirely fit for purpose, it did not exploit the full value that modelling could have brought to the applications. Screening models were used for the following: • Initial assessment of environmental impact due to the hyper-saline discharge • An estimate of the potential for re-circulation • The effects of trenching the intake and discharge pipes • The environmental impacts of discharging process sludge.
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An oceanographic and water quality assessment of the coastal waters was undertaken as part of the environmental assessment. Care was taken to ensure that the assessment identified, or collected, data necessary for the modelling assessment. Key considerations from the oceanographic and water quality assessment were: • The effect of the coastal Algerian current • Residual currents • Weak tidal effects in the locality • The impact and frequency of storms • Temperature and salinity • Water quality • Sediment transport • Water pollution sources The principal concern in terms of marine water quality was the discharge of the hyper-saline effluent from the plant. A first order modelling tool developed by Metoc, termed QUICK-PLUME was used to estimate the potential impact of the hyper-saline discharge. Modelling was based on the predicted operational characteristics of the plant, hydrodynamic data and experience of similar studies in other locations. The modelling conservatively identified potential environmental risk together with measures that could be taken to minimise this risk. A second model developed United States Environment Protection Agency (USEPA), termed Visual Plumes was used to examine the near-field and mid-field behaviour of: disturbed sediments due to trenching of the intake and discharge pipes and; the dispersion of suspended solids associated with discharge of process sludge. It was determined that suspended solids would rapidly return towards background levels and thus process sludge could be discharged on this basis rather than land filling of sludge. The screening assessment tools met the requirements of the environmental assessment and satisfied the auditors of the project. They also assessed risk and, where appropriate, were used to identify practical solutions.
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5.2. Potential added value from environmental design optimisation It was not considered necessary to develop complex numerical models of the coastal waters for the initial screening. This would go beyond the requirements, add to cost and put pressure on tight time scales. However, there was a further consideration that was not taken up as part of the planning and funding application but could have assisted this phase of the project. It was the use of Environmental Design Optimisation (EDO). EDO is a process developed by Metoc that critically examines the operational and environmental variables such that the optimal length, discharge position and diffuser arrangement of the outfall are identified with reference to a similarly optimum intake arrangement. In this case optimal refers to the arrangement that meets the environmental and operational (e.g. minimising re-circulation risk) constraints at the lowest capital and operational cost. In particular EDO would have enabled the developers to fully understand not only the HWD plant’s impact on the environment but also the impact of the environment on the plant. In effect, EDO would have enabled the developer to identify the intake and outfall arrangement that optimises the following: • Minimise capital costs of outfall and intake pipes • Minimise risk of re-circulation • Fully understand the current and future sources of pollution and how they impact the source water • Understand the implications, and if possible design, to minimise pre-treatment costs The overall output from the EDO would have been to minimise the capital cost and the unit cost of produced water. Whilst it was seriously considered as part of the planning and funding application it was identified as a value added component of the work
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phase rather then a requirement of the environmental assessment. However, it is argued that the output from EDO has a place in both the planning and funding applications. Further, the information is important to the design and construction contractor because it better defines their scope of work. 6. Conclusions The use of reclaimed land and a brown-field site is a good option for the plant development. It was recognised that whilst there are environmental challenges, the mitigation of these will generally improve the environmental quality of area overall. This brings a clear convergence of the political, social, economic and environmental objectives. The methodology was developed to serve multiple needs. These included the requirements of various authorities at local and international level together with the requirements of both planning and funding agencies. The methodology took care to harmonise the various requirements and ensure thorough communications. It is concluded that the approach significantly helped to minimise project time scales and cost. The use of screening models was entirely appropriate for planning and funding requirements. It addressed the key issues and identified solutions without the need for detailed model development that would have compromised the project phase.
However, it is argued that Environmental Design Optimisation (EDO) at this project phase would have brought value to the project and would have better informed subsequent project phases.
References [1] Algerian Law No. 83-03 of 5 February 1983 on environmental protection. [2] Decree No. 90-78 — Decree on environment impact assessment. [3] Decree No. 93-184 — Decree on regulating noise emissions which reinforces Article 121 of Law 8303. [4] Algerian law No. 83-17 — relating to the water code. [5] Decree No. 93-160 — Regulating discharges of industrial liquid effluents. [6] Algerian Law No. 03-10 — Relating to environmental protection within the framework of sustainable development. [7] Algerian Law No. 85-05 — On the protection and promotion of health. [8] Algerian Law No. 88-07 — Relating to occupational hygiene and safety. [9] Law No. 02-02 du 5 février 2002 relative à la protection et à la valorisation du littoral. [10] Meeting between Wilaya D’Alger, HWD & Metoc plc on 03/08/04 in Algiers. [11] OPIC Environmental Handbook February 2004, available through http://www.opic.gov/Publications/ envbook_2004.htm. [12] World Bank Pollution Prevention and Abatement Handbook.