ABSTRACT
A good hydrochemical study is well planned in advance, and as little as possible is left to luck or fate. The first stage is a clear definition of the goals or purpose of the study, its extent, and the means available. The answers will differ from one case to another, but there is a common thread: a thorough understanding of the water system under study has to be reached, and that in turn has to be based on high-quality data collected in the field or obtained in laboratories. There is always a limit to the number of water sources, wells, and springs that can be included in a study, there is a limit to the number of periodically repeated measurements possible, and there is a limit to the type and number of laboratory analyses performed. Thus planning of hydrochemical studies is firmly anchored in optimization decisions. This chapter is devoted to these topics.
