Tailor-made concepts for the asset management and the operation of drinking water distribution systems are the essential basis for a sustainable and future-proof drinking water supply in Germany. TZW supports its clients in this challenge with many years of experience and innovative approaches from research and development projects.
Efficient removal of deposits with condition-based network flushing
The activities and developments of TZW in the past years focused on the identification of processes in the drinking water distribution systems in order to develop strategies and recommendations for the operation of the networks with the aim of ensuring a high drinking water quality. A key finding is that end pipe flushing is not necessary or purposeful from the point of view of avoiding bacterial regrowth. Drinking water networks should be flushed to remove deposits. TZW has developed the concept of condition-based network flushing, in which the pipes are flushed according to the velocity of formation of deposits. In addition, systematic flushing can identify microbiological contamination points and determine the concrete colonisation of the network with invertebrates. Flushing of large dimensioned pipelines (Link to the document) is a significant challenge for companies. Meanwhile, concepts exist to remove deposits without interruption of supply or for the avoidance of the accumulation of critical deposit amounts by an adapted operating regime.
Preserving water infrastructure for future generations
In addition to operation, specific concepts are also required for the sustainable maintenance of the water infrastructure. Due to the age of the drinking water systems, considerable efforts will be necessary in the coming years, which can only be managed by economically viable asset management. In addition to maintenance, the renewal and expansion of networks and facilities will play an important role. A prerequisite for the efficient use of the financial resources and capacities required for this purpose is not only the most accurate recording and assessment of the condition of the system, but also concepts for the future design of the network and ways of a successive implementation in existing systems.
The main focus of TZW’s work on condition assessment in recent years has been on the development of a methodology for in situ assessment of the corrosion velocity of drinking water pipes (Link to the document) in order to derive concrete conclusions for sharpening the rehabilitation strategy. In addition, an approach to assess the condition of valves based on specific data obtained during operation has been established. The aim of further work is to continue with the development and testing of innovative non-destructive methods for the inspection of pipes, e. g. using fibre optic sensors, in cooperation with specific companies. In the context of digitalisation, innovations in the field of valves are also pursued by equipping them with sensors for recording parameters such as pressure and temperature. Furthermore, information on the condition of networks can also be expected from the multi-criteria evaluation of data series generated by sensors already present in the network. Initial work here concentrated on the evaluation of disturbances or deviations from normal operation of the supply network, for example to record water losses. A further focus of TZW’s work are material tests as an important part of the condition assessment of water distribution plants.
Analysing consumption data for a sustainable network design
The future network design is mainly determined by the development of the water consumption situation, the requirements resulting from the necessity of securing the water quality as well as the possibilities of using online measuring technology in connection with multi-criteria data analysis for the optimization of network operation. Within the framework of a DVGW research project, the water consumption data of about 25 water companies are currently being investigated with regard to the development of peak demand (Link to the document). On this basis, the peak factors for the planning of supply networks are to be adjusted, with methodical individual differentiation and better integration of new aspects such as climate change and demography. The results of another DVGW research project on short-term forecasting of water demand will be important both for the development of adapted operating strategies and for strategic decisions on network expansion (Link to the document). Effects on the future network design may also result from the ongoing project on water temperatures in the distribution network (Link to the document). Here, fields of action for dealing with the problem are to be developed and tested under practical conditions. The possibilities of using IT development are being investigated within the EU project FIWARE4Water, in which TZW is involved (Link to the document).
Publication (in German)
Korth, A.; Donath, O.: Zustandsorientierte Spülstrategie für Trinkwassernetze. DVGW energie|wasser-praxis 11/2018, 36-41 (2018)