Water pollution caused by wastewater persists despite three decades of effort to clean up European surface waters and despite the requirements of the Urban Waste Water Treatment Directive (UWWTD). Several EU Member States have yet to satisfy the requirements of the directive. A European Commission report released in 2004 noted that several countries had failed to designate sensitive areas and were behind schedule in establishing the capacity of sewage treatment as required by the directive deadlines in 1998 and 2000. As the next deadline is approaching at the end of 2005, for extending sewage treatment to urban areas with more than 2000 inhabitants, the EEA has acknowledged the need to improve our understanding of the inherent implementation problem.