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Solutions
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Water analysis Conducting and evaluating physical-chemical and microbiological water testing in accordance with the German Drinking Water Ordinance and other relevant legal regulations.
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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.
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Treatment technologies Develop sustainable water supply concepts. Implement, monitor and optimise new technologies. Test and further develop existing treatment methods.
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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.
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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.
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Risk management Support for water supply companies to establish a Water Safety Plan. Benefit from our extensive expertise.
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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.
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Research
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Resource protection Protection of water resources, risk management in water catchment areas
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Environmental biotechnology Technical and biological methods for the elimination of microorganisms, microbiological degradation processes
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Microorganisms Developing and applying reliable and sensitive detection methods, evaluating disinfection and treatment measures
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Micropollutants Determination of micropollutants, transformation products and microplastics reliably and sensitively, investigate behaviour in the water cycle, qualified risk assessment
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Waste water and water cycle Use of biological decomposition, developing integrated water supply and waste water management concepts
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New technologies and products Testing and optimizing processes and products to treat, disinfect and post-process drinking water for efficiency, security and robustness
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Asset management and infrastructure Development of management strategies and innovative tools to evaluate the condition of the supply network and its components
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Safety and security, digitalisation and management Digital transformation in public drinking water supply, increase the safety and security of drinking water supply
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- Projects
- About TZW
- Information

Testing of materials and products
A wide variety of materials and products are used in water supply, drinking water installation, fire fighting and in the water and waste water industry. For many of these products there are national and international standards, that specify requirements for the functionality and safety of the products. The quality of materials for drinking water are also subject to strict requirements to ensure that human health is not affected or that the odour or taste of the water are not changed.
We offer our customers tests pursuant to more than 200 different product standards, for which we are accredited according to DIN EN ISO 17025. Each product test, the detailed testing procedure and set up will be discussed and specified individually with our customers. In addition we develop customized test programmes for products that are not yet standardised or develop pre-standardisation projects with our customers. In these activities, TZW works closely with DVGW CERT GmbH as well as with other international certification companies. Furthermore, TZW is active in national and international standardisation work.
What do we offer?
Hygienic and microbiological tests according to KTW-BWGL and other UBA documents
We offer hygienic suitability tests of products and materials in contact with drinking water in accordance with the evaluation criteria and guidelines of the German Environment Agency UBA (e.g. KTW-BWGL, Enamel and Ceramics BWGL, Silicone transitional recommendation). In addition, hygiene tests are carried out pursuant to other European and international standards. This includes testing the metal release of metallic materials as well as testing cement-bound materials, thread-cutting compounds, solders, fluxes and cleaning agents.
On 21 March 2019, the UBA published the evaluation criteria for plastics and other organic materials in contact with drinking water (KTW-BWGL). The KTW-BWGL is intended to gradually replace the previous KTW guidelines for organic materials.. Since 21 March 2021 it is legally binding for plastics, organic coatings and lubricants. However, there are various transition periods to be observed. In March 2022 elastomers and thermoplastic elastomers have also been included in the KTW-BWGL. The KTW-BWGL will become legally binding for these materials as of 01 March 2025. We have published further information in a separate article (link to article) An information sheet (in English) shows the test procedure within the KTW hygiene certification (link to information sheet).
The test centre at TZW is already accredited as a test centre according to DIN EN 17025 for testing according to the KTW-BWGL. In addition, it provides inspectors who are commissioned by the certification body to carry out the technical audits as part of the initial inspection of the plant and the annual monitoring audits.
Contact:
Dr. Johannes Ruppert Tel. +49 721 93163-51, Send e-mail
Pipes and fittings in water distribution and drinking water installations
In addition to a wide variety of product groups such as shut-off valves, tapping bridges, hydrants, check valves, membrane expansion vessels, water meters and sanitary fittings, drinking water heaters, devices for protecting drinking water, and emergency safety showers are also tested according to international standards. Our test range also covers corrugated pipes, pressure-resistant hose lines as well as pipes and pipe connectors. Resistance coefficients (zeta values), which we determine for every component, play a key role in proper planning of a drinking water installation.
Contact:
Stefan Zimmer Tel. +49 721 93163-66, Send e-mail
Systems and equipment for drinking water treatment
Due to the clear comfort trend of individual post-treatment of drinking water there is an increasing demand for the testing of softener, dosing devices and limescale protection systems. These are tested at TZW according to current European standards. This also includes treatment systems for canteen kitchens. In addition we also offer solutions for individual test programmes for products, processes and methods that have not yet been standardised in order to test them for technical and hygienic safety.
Contact:
Heiko Delong Tel. +49 721 93163-20, Send e-mail
UV disinfection devices, UV sensors and UV lamps
In current practice, only mercury-vapour lamps are used to disinfect water. A distinction is made between UV low-pressure lamps and UV medium-pressure vapour lamps. We have test setups that allow us to validate UV devices with a throughput of up to 3,500 m3/h using various test organisms. In addition, our optoelectronic equipment enables us to conduct ageing tests on UV lamps, their characterisation and the qualification of UV sensors. In future, UV LED technology will also be further developed for use in water disinfection, which is why we are already offering specific testing programmes and approaches.
Contact:
Dr. Jutta Eggers, Tel. +49 721 93163-52, Send e-mail
Fire-fighting equipment and fire-fighting facilities
Our testing services also encompass products from fields of work adjacent to drinking water. This includes, for example, the entire extinguishing water sector. Thus the essential products from the fire brigade are tested. These are e. g. steel pipes, couplings, suction connections, adapters and manifolds. Extinguishing water connection systems as well as filling and drainage stations or direct connection points are also tested.Contact:
Contact:
Stefan Zimmer Tel. +49 721 93163-66, Send e-mail
Equipment and methods
- Federal Environment Agency assessment guidelines (KTW and metals)
- Biofilm according to W 270 or DIN EN 16421
- Protection from contamination and back-suction
- Pressure loss test bench
- Pressure change test bench
- Temperature change test bench
- Endurance test benches for sanitary tapware and other valves
- Test benches for the effectiveness of softeners and limescale protection equipment
- UV collimated beam devices
- Test benches for UV lamps and sensors (optical bench, test reactors)
- Test facility for biodosimetric testing of UV devices
Contact
Head of Test Centre

Deputy of Test Centre

Projects
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 moreUltrafiltration as an element of energy efficiency in drinking water hygiene (Ultra-F)
The aim of the project is the holistic and systematic investigation of drinking water installations on the lab scale, in pilot plants and in field…
Read moreBlack biofilms on drinking water taps
The objective of the DVGW-funded study on the occurrence of black biofilms on drinking water taps was to assess the presence and relevance of black…
Read more