Desalination and the environment

Abstract

Water, a limited definite resource, vital for the very existence of life on earth and a necessity for economic and social development and for environment sustainability, is becoming a scarce commodity. This is caused by the population growth, the change of life style, water pollution caused by the human intervention, inefficient use of water and the climatic change with more frequent extreme events such as droughts and floods. Where the availability of water cannot be increased by using conventional resources or by recycling or cannot be made available by demand management methods, the desalination of sea or brackish water offers an alternative solution. The desalination of water has been practiced since ancient times, but was not widely used due to technological limitations, the prohibitive high capital costs, high-energy consumption and finally very high unit cost of water compared to conventional water development. New technological advances in the last 30 years reduced tremendously the capital cost and the energy consumption so that desalination projects can be considered as alternative solutions to water development. However, desalination projects are still not very cheap to be easily accommodated by the economies of many countries, energy consumption is still comparatively high, and acceptance of such projects is questioned by environmentalists, politicians, engineers and other groups of the population on economic, social and environmental issues. This keynote speech on Desalination and the Environment will outline the approach to be followed on evaluating the need and the feasibility for a desalination project. The approach considers natural water resources availability including risk assessment, water demand for economic and social development and environmental sustainability, existing water allocation and possible reallocation, water supply and water demand management. It also considers for what purpose to desalinate water, how much to desalinate, for how long, siting of the plant, steps for scientific, engineering, social and environ- mental acceptance and environmental mitigation measures. The additional energy demand compared to the al- ready existing demand within the Kyoto Conventions must be considered and advantages and disadvantages of different forms of energy are to be examined. Environmental effects on the sea environment, the air, land and on the region as well as on the regional development plans are to be minimized. Finally, the costs are to be considered including the effects on the total economy of the country and the financing options. The presentation will be highlighted with examples from the Cyprus experience.