Alpine infrastructure in Central Europe: integral evaluation of wastewater treatment systems at mountain refuges

Planning, construction and operation of onsite wastewater treatment systems at mountain refuges is a challenge. Energy supply, costly transport, limited water resources, unfavourable climate and load variations are only some of the problems that have to be faced. Additionally, legal regulations are different between and even within countries of the Alps. To ensure sustainability, integrated management of the alpine infrastructure management is needed. The energy and water supply and the wastewater and waste disposal systems and the cross-relations between them were analysed for 100 mountain refuges. Wastewater treatment is a main part of the overall 'mountain refuge' system. The data survey and first analyses showed the complex interaction of the wastewater treatment with the other infrastructure. Main criteria for reliable and efficient operation are training, technical support, user friendly control and a relatively simple system set up. Wastewater temperature, alkalinity consumption and high peak loads have to be considered in the planning process. The availability of power in terms of duration and connexion is decisive for the choice of the system. Further, frequency fluctuations may lead to damages to the installed aerators. The type of water source and the type of sanitary equipment influence the wastewater quantity and quality. Biosolids are treated and disposed separately or together with primary or secondary sludge from wastewater treatment dependent on the legal requirements.