Determination of investment cost functions of water treatment plants

Abstract

Functions representing the relationship between the capacity of a water treatment plant and its investment cost are found in studies by Orlab and Lindorf, by Koening, and by Ackermann, These functions were based on samples of plants constructed in the long period of 1930's - early 1960's. To update the above studies, this study determines similar investment cost functions for the surface-water and ground-water plants, using samples of plants mostly constructed in the short period of 1968-1971. Further, it determines similar cost functions for major components of each type of plant that have not been available in the past studies. A significant difference exists between the result of this study and the results of the past studies on the surface-water plant. The cost functions of the past studies indicate economies of scale in investment cost, whereas the function of this study indicates small but positive diseconomies of scale.