For each stream, three concentration ranges were given: low, typical, and high. The ranges are wide to cover most of the situations in WWTPs. However, they do not cover extreme cases, but these are discussed when possible. As much as possible, references giving an overview of several installations were prioritized. For some parameters, data are not widely available, but the value given was always based on a minimum of three different sources. It is important to note that different analytical techniques were employed to measure the same parameter depending on the reference, which can lead to differences in the concentration ranges obtained.