The aim of the project is to modernise the Przechlebie waste water treatment plant in the municipality of Zbrosławice. The modernisation of the treatment plant includes the reconstruction of the waste water tank, the retention, the fitting of a new sievebox, the reconstruction of the main pumping station, the construction of a biological reactor with a secondary settler, the adaptation of Imhoff settlers to the oxygen stabilisation chambers, the construction of the blower station and the sediment dewatering building, the extension of the administrative building together with the execution of the underground network and land development. Thanks to the implementation of the project, the waste water treatment plant will become a flow-through treatment plant that effectively reduces organic and nutrient compounds. The planned size of the treatment plant will be 1000 m³/d at p.e. = 6400 and the supply of waste water will be 955 m³/d at p.e. = 6360. The project will increase the share of the population using the urban waste water treatment system compliant with the Urban Waste Water Directive.