To demonstrate the effects of increased extraneous water on operation, purification, and energy efficiency, two wastewater treatment plants (WWTPs) have been investigated in detail under the research project 'Sealing of sewer pipes - Effects on the purification performance of WWTPs and their impact on the local water balance'. Both treatment plants, after evaluating and analyzing the measurement data and information about them, were compared in the light of existing literature and other practical investigations. Furthermore, the results were assessed with respect to transferability to other treatment plants. In WWTP 1, extraneous water reduction led to lower energy consumption of certain plant components such as the pumping station and aeration. An increased percentage of extraneous water had an impact on the wastewater characteristics (e.g. organic load) in WWTP 2. A decrease in extraneous water increases the concentration of biodegradable matters; however, an increase in extraneous water increases the loads in the effluent. The results are in accordance with the theoretical approaches described in the literature and confirm the correlations between extraneous water and purification efficiency and energy consumption of WWTPs.

In the research project entitled "Disposal of treated residues in Alpine areas", the options for the disposal of residues (sludge) were investigated considering the existing ecological and economical perspectives. Issues of nature conservation, soil conservation, water conservation, agriculture and forestry, climate protection and waste management were included considering the legal and technical basis. In addition, hygienic and esthetic aspects were also taken into consideration. The energy and water supply and the wastewater and waste disposal systems were analyzed for 45 Bavarian mountain refuges. Experiences from operation of their supply and disposal systems were investigated. The problem of supporting decision-and policy-makers in managing issues related to waste water and disposal of residues was addressed within the context of this project. As a result, a guideline and a practical decision making concept for the disposal of residues from wastewater treatment in sensitive mountain regions were elaborated. This paper reveals insights into general assessment criteria that can support the quest for solutions to sustainable waste management in other protected areas and mountain regions. This study presents a guideline supporting Alpine Associations and technical and enforcement authorities while making decision on a sustainable residue disposal.

In recent years, wireless measurement and control units have become more popular for monitoring water distribution systems in the drinking water supply. Electric power supply for a higher number of devices through fixed connections to the public electrical grid is technically complex and requires large investments. Powering monitoring devices, which are installed in areas where electrical power supply is lacking, is difficult and considerably increases personnel and operational costs due to frequent battery changes. In such cases, harvesting energy from the water distribution systems or the environment would be an attractive option. In this work, an energy-self-sufficient system has been developed to solve these problems. The system transforms, by use of an energy harvester, the kinetic and hydraulic energy of water flow in a pipeline to electrical energy, stores this energy, and uses it via a micro-controller unit for measurements and wireless data transmission to a central server.