Water analysis Conducting and evaluating physical-chemical and microbiological water testing in accordance with the German Drinking Water Ordinance and other relevant legal regulations.
Testing of products and devices Initial testing of products and materials in contact with drinking water. Our Test Centre is accredited for more than 200 different product standards according to DIN EN ISO 17025. Test and develop UV technology.
Treatment technologies Develop sustainable water supply concepts. Implement, monitor and optimise new technologies. Test and further develop existing treatment methods.
Micropollutants and microorganisms Develop and improve the method of determination using cutting-edge equipment. Investigate the presence, behaviour and retention of inorganic and organic micropollutants in the water cycle and drinking water treatment.
Network management and drinking water installation Microbiological quality change, deposit formation and cleaning and optimisation of the distribution network operation. Evaluate and analyse corrosion damage.
Risk management Supporting water supply companies in risk management, based on our comprehensive expertise
Drinking water catchments and resources Support for water supply companies to establish a Water Safety Plan. Benefit from our extensive expertise.
Environmental biotechnology and contaminated sites Evaluation of the decomposition potential at contaminated locations. Development of sustainable ways to eliminate pollutants from the environment. Employ a combination of microbiological and technical methods.
Digitalisation Water demand forecast, Evaluation of water quality and quantity data, Regression and classification models, Machine learning, AI, Databases, GIS-application
Resource protection Protection of water resources, risk management in water catchment areas
Environmental biotechnology Technical and biological methods for the elimination of microorganisms, microbiological degradation processes
Microorganisms Developing and applying reliable and sensitive detection methods, evaluating disinfection and treatment measures
Micropollutants Determination of micropollutants, transformation products and microplastics reliably and sensitively, investigate behaviour in the water cycle, qualified risk assessment
Waste water and water cycle Use of biological decomposition, developing integrated water supply and waste water management concepts
New technologies and products Testing and optimizing processes and products to treat, disinfect and post-process drinking water for efficiency, security and robustness
Asset management and infrastructure Development of management strategies and innovative tools to evaluate the condition of the supply network and its components
Safety and security, digitalisation and management Digital transformation in public drinking water supply, increase the safety and security of drinking water supply
- About TZW
Providing drinking water of highest quality at the tap is one of the primary goals of water supply. This places high requirements on the drinking water network operator. Despite all efforts, it is not possible to entirely exclude variations in quality during water distribution. Targeted measures need to be taken to control and eliminate abnormalities. These measures frequently require detailed knowledge of the complex processes involved in the distribution system. TZW works hard to clarify these processes using specialist methods of analysis and concepts. We offer water supply companies consultation on all aspects of drinking water quality assurance in the distribution system and support them in the development of specific network management strategies.
Pitting corrosion and perforations in galvanised steel, copper and stainless steel can cause damage to water supply systems. We have in-depth technical expertise on this subject and offer comprehensive damage investigations.
Condition-based flushing of drinking water networks
Brown or turbid water is a frequent quality issue in drinking water distribution and is caused by the mobilisation of deposits in the pipes. TZW has developed the concept of condition-based network flushing. This is based on flushing individual network sections once deposit build-up has reached a critical potential. TZW offers its support for the implementation of a condition-based flushing strategy. This includes developing flushing schedules, conducting, evaluating and scientifically assessing the flushing processes as well as defining tailored flushing intervals and districts.
Assessment of corrosion inhibitors
Corrosion inhibitors are primarily used in water distribution with the aim of avoiding rusty water. Continuous turbidity measures are ideal for assessing the need to add inhibitors or to optimise the inhibitor composition as well as the additive quantity under the specific distribution system conditions. The corrosion behaviour of the pipe materials in the network can be evaluated in detail using turbidity curves. TZW defines the representative measurement points, provides the measuring instruments and prepares recommendations on inhibitor use after evaluating the turbidity curves.
Identification of microbiological contamination points
In practice, routine testing is frequently revealing isolated findings of coliform bacteria or enterococci. Findings may relate to an indicator for latent pollution or for a sporadic contamination. TZW established the following approaches to quickly and clearly identify contamination points, which have been tried and tested in a range of cases in practice:
- Microbiological sampling in conjunction with systematic flushing to check colonisation in the network.
- On-site enrichment of bacteria using the MikroSens filtration system, developed by TZW, to increase test sensitivity.
- Molecular biological identification to assess hygienic relevance
Preparation of schedules of measures and action plans
According to Section 16 (5) of the German Drinking Water Ordinance, every water supply company is obliged to create a schedule of measures that considers the regional water supply conditions. It is particularly recommended that water supplies without continuous disinfection also create action plans based on the DVGW worksheet W 1020 in addition to a schedule of measures. These contain rules on what to do if microbiological limits are exceeded with the aim of supplying consumers hygienically flawless drinking water at all times without any restrictions on use.
Cause analysis for non-compliance of microbiological limit values in drinking water
Microbiological problems in drinking water can have a variety of causes. TZW offers consultation for water supply companies, authorities, industry and other partners on microbiological limit breaches and hygienic problems in drinking water treatment, distribution and installation.
Anomalies caused by invertebrates can also arise in water distribution. Using a filtration system developed by TZW, invertebrates are enriched as part of network irrigation and these are then quantified and identified in the lab. As part of a systematic procedure, the exact population density per pipe section is determined and corrective measures are devised and/or evaluated.
Cause analysis for corrosion damage
Corrosion damage negatively impacts water quality and in the worst case it may cause water leaks. These issues often cause consequential damage to buildings. In addition to a thorough survey taking into account all associated aspects, we conduct corrosion-chemical investigations and cut materials which help to determine the type and cause of damage for the most diverse metallic and non-metallic materials.
Methods and equipment
- Utility vehicles with flushing device to record the deposit situation and flushing speed
- Mobile online turbidity measuring devices for installation in the network
- TZW software “OptFlush” to calculate flushing intervals
- On-site bacteria enrichment systems “MikroSens”
- Molecular biological identification procedure
- Filtering system for enriching invertebrates
- Algorithms for time series analysis
Fourier transform infra-red spectrometer (ftir spectrometer)
Wricke, B.; Korth, A.; Richardt, S.: Minimierung sedimentbürtiger Gütebeeinträchtigungen durch modellgestützten Rohrnetzbetrieb. Veröffentlichungen aus dem Technologiezentrum Wasser Karlsruhe [Minimisation of sediment-induced quality issues by means of model-based pipeline operation. Publications from TZW Karlsruhe]. Volume 48, (2010)
Korth, A., Donath, O.: Zustandsorientierte Spülstrategie für Trinkwassernetze [Condition-based flushing strategy for drinking water networks]. Energie- und Wasserpraxis, 11/2018, (2018), p. 38-41
Wricke, B., Korth, A.: Hygienische Sicherheit im Verteilungsnetz – Teil 2: Erkennen und Beseitigen der Ursachen mikrobiologischer Güteveränderungen [Hygienic safety in distribution networks – Part 2: identification and elimination of the causes of microbiological quality changes].. Energie- und Wasserpraxis 11/2016, (2016), p. 32-41
Korth, A. and Lohmann M.: Bewertung der Wirkung von Korrosionsinhibitoren im Verteilungsnetz
Veröffentlichungen aus dem Technologiezentrum Wasser Karlsruhe [Assessment of the effect of corrosion inhibitors in distribution networks. Publications from TZW Karlsruhe]. Volume 82, (2018)
Hügler, M., Petzoldt, H., Korth, A.: Innovativer Ansatz zur Ursachenanalyse mikrobiologischer Belastungen. Veröffentlichungen aus dem Technologiezentrum Wasser Karlsruhe [Innovative approach for the cause analysis of microbiological pollution. Publications from TZW Karlsruhe]. Volume 70, (2015), p. 45-57
Volumes from the TZW publication series can be purchased here.
Water reuse and drinking water reservoirs on trial (FLEXITILITY)
The Flexitility research project entered its implementation phase in October 2022. Until 2024, network partners from practice and research will test…Read more
Increased temperatures in the drinking water distribution network (MibiTemp)
The Project aims on a general understanding of the effects of increased water temperatures on resilience and vulnerability of microbial communities…Read more
Optical-acoustic inspection of drinking water distribution systems (OptInspekt)
Within the scope of inspection projects at water supply companies, the project investigates under which conditions an optical and acoustic inspection…Read more