In the field of water technology, we deal with technological processes of drinking water treatment, wastewater treatment, and water recycling. We address technological aspects of water management, the impact of wastewater on surface waters, and the possibilities of their recycling. Special attention is focused on the removal of substances from the PPCP group (Pharmaceuticals and Personal Care Products) from wastewater at WWTPs. Furthermore, we check the proper functioning of equipment designed for wastewater treatment, drinking water treatment, and sludge and sediment treatment in the form of semi-operational experiments and tests. Wastewater is also used as a source of information on the population’s health and lifestyle, using the so-called epidemiological approach. From wastewater, it is possible to infer, for example, the level of drug consumption or the development of the Covid-19 epidemic in monitored areas.