Cost Estimating for Conventional Water Treatment

The Safe Drinking Water Act of 1974 emphasizes the need to take costs into consideration when promulgating regulations. This paper presents cost equations that can be used for water treatment unit process cost estimating. The need for pre-design estimates is discussed, and the factors affecting the reliability of cost estimates is examined. These factors include availability of basic data, stage of development, definition of scope, the time expended on analysis, and experience of the analyst. Data for these equations were derived from a carefully designed study to establish water supply unit process costs on a consistent and understandable basis. The basis for derivation of these curves is presented. Examples of the application of these equations are developed based on a standard layout for a water supply treatment plant and assumed standard values for the input factors for the cost equations.