A methodology for comparing water desalination to competitive fresh water transportation and treatment

Abstract

The comparison between desalination and other water supply methods i usually based on a conventional economic evaluation which typically takes into account the direct capital and operating costs and utilizes techniques and criteria which differ from designer to designer. While this method is usually adequate when one of the alternative water supply methods is clearly superior, the comparison must be much more systematic and comprehensive where the alternatives are competitive. This paper presents a methodology for such a comprehensive evaluation, addressing the complete water supply-disposal chain and taking into consideration technical, environmental, economic, and political/legal aspects of the problem. Actual examples, mainly from the experience of the Southwest Florida Water Management District, are provided to illustrate the methodology. The economic analysis is based on a present-value life-cycle cost model which accounts for interest, tax, insurance and escalations in energy, labor and material costs.