Cost-Effectiveness Analysis of Wastewater Reuses

The purpose of this paper is to demonstrate, by means of a case study of water reuse, the usefulness of applying Kazanowski's cost-effectiveness approach to civil engineering systems. This method facilitates evaluating and comparing alternative systems designed to reach a given goal. The case study is concerned with two concurrent problems that are commonly facing metropolitan areas: securing an adequate water supply and disposing of the sewage effluent. Several distinct alternative systems to deal with these problems are identified, such as exchange for irrigation water, or tertiary treatment and recycling. For each alternative system, the economic analysis, the environmental impact upon implementation, and the horizontal and vertical externalities are evaluated and presented in tabular form. The result of a sensitivity analysis performed on major system variables is given.