Despite the huge investments made in the wastewater infrastructure sector, managing wastewater remains an important challenge for most of the countries in the Danube River Basin (DRB). The EU Urban Wastewater Treatment Directive (UWWTD) and the EU Water Framework Directive (WFD) mandate significantly higher levels of collection and treatment than is currently the case in many Danube countries. These obligations require additional substantial investments supported by implementation programs. The new infrastructure that is being built or needs to be constructed creates financial, technical and management strains for national and local authorities, utilities and service providers in the region.