OVERVIEW

Water treatment process selection is a complex task. Circumstances are likely to be different for each water utility and perhaps may be different for each source used by one utility. Selection of one or more water treatment processes to be used at a given location is influenced by the necessity to meet regulatory quality goals, the desire of the utility and its customers to meet other water quality goals (such as aesthetics), and the need to provide water service at the lowest reasonable cost. Factors that should be included in decisions on water treatment processes include:

• Contaminant removal

• Source water quality

• Reliability

• Existing conditions

• Process flexibility

• Utility capabilities

• Costs

• Environmental compatibility

• Distribution system water quality

• Issues of process scale

This chapter begins with a brief discussion of alternatives to water treatment, followed by a review of the various factors that may influence the selection of a water treatment process. After these factors are covered, the chapter presents examples of water treatment process selection and explains the reasons for the choices made in the examples. The capabilities of commonly used treatment processes are presented in detail in the subsequent chapters of this book.

WATER SUPPLY APPROACHES

Use of the best source water quality that can be obtained economically is a concept that has been advocated by public...