Integrated waste water management for a small river basin - a case study

In Austria approximately 70% of the population is connected to sewerage and to biological waste water treatment plants. Whereas the urban areas are already provided with these facilities to a very high extent, effort is still needed in rural areas to meet the requirements of the Austrian legislation. The way, this task should be solved has provoked much controversy. It is mainly the question, whether centralised or decentralised sewage disposal systems are preferable from the ecological and economical point of view, that became a political issue during the last 5 years. The Institute for Water Quality and Waste Management was asked to elaborate a waste water management concept for the Lainsitz River Basin, a mainly rural area in the north of Austria discharging to the Elbe river. Both ecological and economical aspects should be considered. This paper presents the methodology that was applied and the criteria which were decisive for the selection of the final solution.