The place of implementation of the project is Hungary, the municipality of Sárospatak. The Sárospatak waste water disposal agglomeration is in force 25/2002. It is indicated in Table 2 of Government Decree (II.27.) that the municipal sewerage network (CS) and the development of an existing waste water treatment plant (TF) are concerned with tasks. The technical content of the project follows the classification of waste water agglomeration according to the Regulation. The amount of sewerage reconstruction to be declared does not exceed 5 % of the eligible costs. The majority of the city is equipped with a sewerage network, the project requires the extension of the existing sewerage network and the reconstruction of the existing system. Given the current conditions of the existing waste water treatment plant (volumes, mechanical characteristics), the actual biological purification capacity of the existing waste water treatment plant is below the requirements of the valid operating permit and therefore the biological purification capacity of the plant needs to be increased in order to ensure the long-term compliance of the limit values. The development of the waste water treatment plant will take place within the boundaries of the existing operational waste water treatment plant in Sárospatak using the existing infrastructure and the creation of new technological units.