An integrated assessment of options for rural wastewater management in Austria M. Starkl*, M. Ornetzeder** , E. Binner*, P. Holubar*** , M. Pollak**** , M. Dorninger***** , F. Mascher****** , M. Fuerhacker* and R. Haberl* *Department for Water-Atmosphere-Environment, University of Natural Resources and Applied Life Sciences, Vienna, Austria, Muthgasse 18, 1190 Vienna, Austria (E-mail: markus.starkl@boku.ac.at) **Centre for Social Innovation (now: Austrian Academy of Sciences - ITA), Vienna, Austria ***Department for Biotechnology, University of Natural Resources and Applied Life Sciences, Vienna, Austria ****wpa consulting engineers, Vienna, Austria *****Department of Sustainable Agricultural Systems, University of Natural Resources and Applied Life Sciences, Vienna, Austria ******Institute of Hygiene, Medical University of Graz, Austria Abstract This paper reports a recently finished, interdisciplinary project on rural wastewater management in Austria. The objective of the project was to study alternative wastewater management options based on separation of the wastewater into its constituent parts, and to compare them with conventional ones. Thereby, a feasibility study of both conventional and alternative options for wastewater management in six model regions was carried out. Life cycle costs and social acceptance were analysed by using a case study-based assessment approach. However, hygienic and environmental risks were evaluated on a more general level. In order to complement the findings, a survey on urine separation system users in the Solar City of Linz was conducted. Based on these assessments and empirical findings, the paper concludes that options using a full separation of all wastewater fractions should be considered with care. Options based on a separation of only grey water and black water or in the liquid/solid phase can offer ecological and financial advantages over conventional options. Further, options combining wastewater management and regional biogas plants were identified as an interesting solution. However, legal constraints restrict this option currently. Keywords Assessment; case studies; integrated assessment; options; risks; wastewater management Introduction In Austria, about 10– 15% of the population still does not have an adequate wastewater management system. For instance, in the province of Lower Austria about 200,000 inhabitants are still connected to cesspits or simple mechanical treatment systems. Furnishing these rural communities with conventional, centralised technologies would create high costs. As urban water management is subsidised by the federal government, these costs are of great political concern. For instance, the Austrian Kommunalkredit AG (which manages the funds for urban water management on behalf of the Ministry for Agriculture, Forestry, Environment and Water Management) spends about 250,000 EUR/ year on subsidies for urban water management. Further, the highest subsidies are avail- able for areas with a low connection density (the top funding rate is currently 70% of investment costs). Moreover, in recent years, the traditional combined flow options for wastewater management have been criticised by several authors (e.g. Larsen and Gujer, 1996; Otterpohl et al., 1999; Wilderer and Schreff, 2000). These authors, among many others, argue that the traditional method of sanitation does not reuse the nutrients which wastewater contains, and that the invested capital is tied up in infrastructure (sewerage Water Science & Technology Vol 56 No 5 pp 105–113 Q IWA Publishing 2007 105 doi: 10.2166/wst.2007.562