References Model project in Slovenia – "License model Maribor": The sewage treatment plant that is currently under construction in Maribor will have a capacity of 190,000 population equivalent and uses fully biological treatment methods. The license model, which is the first of its kind in Slovenia, is a BOT model with a term of 30 years. The mechanical/chemical treatment section was taken into operation in June 2002. First privatization tests in Austria – "BOT model Waidhofen/Thaya": ariwa’s new purification plant, a subsidiary of aqua plus GmbH/Vienna, celebrated its opening on 26.09.2003. The purification plant, on one hand, has been built fully automatic after implementation of the innovative SBR- process. The whole model, on the other, represents the very first application of an operation model of purification plant in Lower Austria. Dr. Rainer Wiedemann, managing director of aqua plus, believes the innovative operation model, which has been developed together with the municipality of Waidhofen, having further advantages, such as reduction of the municipal budget and lowering of investment costs.