Compounds such as pharmaceuticals, or personal care products are only partially removed in wastewater treatment processes. Large number of these compounds and their degradation products is out of any control. A small number of compounds are covered by legal regulations. Among the compounds non-regulated by law, the target compounds, as well as non-target compounds can be distinguished. In the scientific literature, number of reports on various target compounds’ determination is increasingly growing. This paper provides an up-to-date review on micropollutants present in treated wastewater and their concentrations found in literature in the years 2015–2019. Because the obtained results of chemical analyses do not adequately reflect the risks to ecosystems and consequently humans, the results of chemical analyses have been supplemented by a review of ecotoxicological studies. In addition, legal issues linked to contamination of treated wastewater and research related to identification of non-target compounds in treated effluents have been discussed.

The assessment of a hazard resulting from the pollution of the environment by chemical compounds is in principle limited to the determination of their concentrations in its various compartments. But for solving many problems in this context, knowledge of the emission sources, transport pathways, and sites of deposition is of great benefit. By far the largest amounts of pollutants, regardless of where they were discharged, end up in the soil or the aquatic environment. By defining the source of origin of compounds like PAHs, and PCBs in the environment, especially in areas where they are emitted from different sources, it is possible to obtain information on the nature of different materials that are sources of these compounds (e.g., petroleum), or on the processes during which they are formed (e.g., combustion). In addition, the fate of toxic compounds in the environment can be tracked. This knowledge enables hypotheses to be formulated regarding the course of environmental phenomena; it also supplies a tool for taking administrative action and for resolving disputed issues concerning environmental pollution.