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6.1
Conclusions
6.2 Recommendations for further study
Chapter 6 focuses on the conclusions of the application studies in chapters 35. Remarks on the technical feasibility and cost-effectiveness of the proposed new technology of hydro-powered reverse osmosis (RO) desalination and its application to non-conventional water-resources development alternatives are summarized in the context of national and/or inter-state water master planning. This summary also takes into account the concluding remarks of the review studies in section 2.12 of chapter 2.
From the case study on non-conventional water-resources development in Kuwait, the unit cost of brackish-groundwater RO desalination was estimated to be US$0.40/m³ with and US$0.60/m³ without the hydro-potential energy in the water pipeline system (200 m of differential head). The cost of hydropowered brackish-groundwater RO in these circumstances is estimated to be as low as one-sixth to one-fourth of the cost of conventional seawater desalination either by MSF (US$2.70/m³) or RO (US$1.70/m³).
The potential of brackish waters, both groundwater and surface water, which have long been neglected in water-resources studies, has to be evaluated in the context of national water master planning, taking into account the water quality in the aquifers and the promising progress being made in RO desalination technologies.
The case study of national water-resources master planning in Jordan identified two schemes, the Al-Wuheda dam and Disi fossil groundwater development, as key projects to sustain national water-resources development after the 1990s. The fossil groundwater in the Disi aquifer, however, should be conserved for emergency use only. After completion of the Al-Wuheda dam on the Yarmouk River by the end of the 1990s, non-conventional waterresources development, including desalination of brackish water and the reuse of treated sewage effluents, will become the key technologies in future water plans for Jordan.
The proposed co-generation approach to brackish-groundwater development with hydro-powered RO desalination using the existing DisiAqaba water-supply system will conserve the fossil groundwater in the Disi aquifer and produce both hydro-electricity and fresh water, including 14.6 million m³ of fresh water per water with potential hydropower generation at 15,900 MWh per year. The sustainable management or conservation of the non-renewable fresh groundwater in the Disi aquifer is possible by developing the brackish groundwater in the Kurnub aquifer, which has never been tapped. The unit cost of brackish-groundwater desalination by hydro-powered reverse osmosis is estimated to be US$0.41/m³.
The proposed integrated co-generation approach, coupling the Mediterranean-Dead Sea (MDS) solar-hydro scheme with hydro-powered RO desalination, will be able to produce 100 million m³ of fresh water per year and 500 MW of electricity, which is about 10% of Israel's national grid's capacity of 5,835 MW in 1991. The 1 x 109 kWh of electricity generated per year would have to be shared by the two riparians, Israel and Jordan, to supply their peak demands, while the product fresh water is to be exclusively used and shared in the water supply for the central Ghor (Jordan valley). The unit water cost of seawater desalination by hydro-powered reverse osmosis is estimated to be US$0.68/m³. The much discussed MDS conduit scheme could thus be realizable by introducing new technology and the nonconventional concept of sharing resources in the context of an inter-state water-resources development master plan.
The Al-Wuheda dam project and other side-wad) dam schemes such as flood retention or groundwater recharge dams, together with RO desalination to salvage brackish water from saline springs and irriga tion return in the lower Jordan River system, all of which would enhance the solar-hydro potential of the Dead Sea, should be linked with the MDS conduit scheme in a sharing of valuable inter-state resources and benefits in the context of an integrated development plan. This would not create any new political conflicts but rather promote peace and economic development for Jordan, Palestine, and Israel. Any storage or retention dam schemes and the lower Jordan Peace Drainage Canal scheme with RO desalination will have prominent priority in a short- to medium-term strategy.
The proposed joint inter-state basin-development master plan for the Jordan River system would now seem to be a practical possibility, being not only technically and economically feasible but also politically desirable and urgent.
The interregional economic development planning will need to cover the Dead Sea (Israel/Palestine/Jordan) and Aqaba (Egypt/Israel/ Jordan). These two geopolitical regions have a prominent place in the peace process and will be a gateway to cooperation among all the countries of the Middle East. The Mediterranean-Dead Sea or Red Sea-Dead Sea conduit scheme and Aqaba hybrid seawater pumped-storage with hydro-powered RO desalination for cogeneration are possibly of even greater importance for economic development, including tourism, housing, commerce, and the industry of the whole region.
Further research will be needed to evaluate the technical and institutional feasibilities of the Mediterranean-Dead Sea or Red Sea-Dead Sea conduit scheme and Aqaba hybrid seawater pumped storage with and without hydropowered RO desalination.
Technical issues requiring study include:
>> reassessment of the actual evaporation that will occur from the surface of the Dead Sea after impounding seawater from the Mediterranean, including in-situ tank trials and laboratory model tests;
>> environmental assessment to predict the climatic change and the ecological effect on life in the area;
>> prototype trials of low-pressure-type (40-50 kg/cm²) membrane modules for seawater RO desalination, including the extension of life from the present three years up to five to seven years;
>> design of materials to avoid corrosion of hydraulic structures from seawater and brine reject water.
Institutional issues include:
>> riparian-rights issues relating to multinational use of the Dead Sea surface, including the allocation of potential energy from evaporation from its surface;
>> long-term demilitarization of the Mediterranean-Dead Sea or Red SeaDead Sea conduit route and arrangements for project management by an international agency such as the United Nations, including the establishment of the Middle East Development Bank.