Hygiene Inpections of Dinking Water Installations in Buildings in accordance with VDI 6023

If problems arise with the drinking water quality in a building’s water system, for instance in the event of an outbreak of Legionnaire’s disease, the owner or management of the building immediately comes into conflict with Section 4 of the latest German Drinking Water Ordinance. This requires that generally recognised engineering rules be adhered to. If general deficiencies exist or deviations from these rules are recognised then the management is liable.

To prevent problems occurring VDI 6023 ’Hygiene requirements of drinking water installations in buildings’ provides for hygiene inspections to be carried out so that health risks, especially in large complex building installations, can be objectively assessed. And if hygiene problems already exist, the hygiene inspection acquires all the more significance. Indeed only by analysing the complex interplay between the water chemistry, physical and hydraulic parameters as well as the microbiological situation in the building’s water system is it possible to find a permanent solution to the problem.

Our services range from hygiene/technical inspections of buildings and analyses of water installations to microbiological and chemical investigations, and to the design of remedial measures and also the supervision and control of such remediation work.

On our education site you will find our training courses for drinking water hygiene according to VDI 6023.

Those are held in German Language only


Christian Büning

Am TÜV 1
(Am Technologiepark 1)
45307 Essen

Tel +49 201 172 1367
Fax +49 201 172-1606


VDI / DVGW 6023 - Hygiene in drinking water installations

With the latest amendments to the Drinking Water Ordinance (TrinkwV), extended requirements also arise for operators of drinking water installations in buildings. This is due to the fact that the serious health problems caused by legionella are mainly related to poor drinking water quality in drinking water installations of buildings. Already in the run-up to these amendments, the VDI / DVGW 6023 Directive has taken a holistic approach to the topic of drinking water hygiene, described the problems and defined requirements. These concern the production, planning, construction, maintenance and operation not only directly concern, but above all also the interfaces between these.

This is not only an obligation to inspect the legionella, but also the obligation to test drinking water and the statutory obligation to carry out a hazard analysis, if the technical measure for legionella (100 colony forming units (CFU) / 100 ml) is exceeded.

What are the risks of hygienic deficiencies in drinking water installations?

The health risks associated with the use of drinking water can result from chemical as well as microbiological stress. In the case of chemical loads, an acute hazard to drinking water users is very unlikely. The primary focus here is on the long-term prevention of possible chronic health impairments, For example by lead.

In contrast, risks caused by pathogens in drinking water can lead to acute hazards in the form of infections. According to current knowledge, it is mainly bacteria from the group of legionella from which a significant risk potential in drinking hot water installations emerges. These microorganisms can lead to so-called legionellosis. As an easy progression, the Pontiac fever, this infection shows summer flu-like symptoms. Estimates are based on an annual fall in the six-digit range. In the case of the severe progression of legionellosis in the form of lung inflammation, the legionnaires' disease, the Robert Koch Institute, Berlin, also assumes a considerable underwriting of the cases and a dark figure of> 95%.

After evaluating the findings to date, it is assumed that approximately 800,000 outpatient pneumonia acquired annually is about 4% due to legionella (see also the Justification of the Drinking Water Act). This is about 32,000 illnesses a year with the consequence of about 2000 deaths. This shows the current darkness and the extent of the problem.

In which areas is the guideline VDI / DVGW 6023 valid?

The VDI / DVGW 6023 applies to all drinking water installations on land, in buildings and on merchant ships (including inland waterways). This also includes the "installations of the drinking water installation, from which drinking water .... To consumers (permanent water distribution) ", which fall under §3 of the Drinking Water Ordinance.

Is there a legal obligation to implement the VDI / DVGW 6023?

The VDI / DVGW 6023 is one of the most important generally accepted rules of technology for drinking water installations. The Drinking Water Ordinance requires that the generally accepted rules of technology must be complied with in §4 and also in various places. This concerns the aspects of manufacturing, planning, construction, commissioning, use, operation and maintenance.

It follows that all parties involved must implement the VDI / DVGW 6023 or alternatively equivalent measures. In the case of deviations from the requirements of VDI / DVGW 6023, their effectiveness must be documented. Finally, the VDI / DVGW 6023 is the safest solution, especially to meet the operating requirements! In order to prevent contamination, a hygiene inspection in conjunction with a hygiene plan can provide clarity about the current hygienic condition of the plant.

What are the objectives of VDI / DVGW 6023?

The Directive defines requirements for the hygiene of drinking water installations. This is the totality of all efforts and measures for the prevention of indirect or immediate health impairments and disturbances of the well-being of the individual user.

The aim is to preserve the perfect drinking water structure in the drinking water installation and to comply with the limit values of the drinking water ordinance.

What are the requirements of VDI / DVGW 6023?

For example, The VDI / DVGW 6023 defines hygienically justified structural, technical and organizational requirements with regard to the planning, manufacture, execution, operation and maintenance of drinking water installations. The planning may only be carried out by experts.

As a planning basis a room book with the usage description and a complete concept of the drinking water installation must be available. With reference to other regulations, such as DIN 1988 and EN 1717, requirements for the construction, the material to be used, as well as necessary maintenance measures, including the controls, are described.

Also, interruption operations, e.g. Are subject to the requirements.

The VDI / DVGW 6023 systematically describes these requirements and also deals in detail with the interfaces between the partial tasks. The details are, among other things, the subject of the u. Drinking water hygiene training.

Is there a test obligation for drinking water installations according to VDI / DVGW 6023?

The obligation to test is derived from the Drinking Water Ordinance and the associated requirement for adherence to the generally accepted rules of technology. Within the framework of the commissioning of the drinking water installation, an initial hygiene inspection is to be carried out in accordance with VDI / DVGW 6023.

At the same time, compliance with the requirements for planning and installation must be thoroughly tested before filling the drinking water installation. This test may only be carried out by qualified persons with additional hygienic qualification.

A further test obligation, which relates to legionella in drinking water installations, is derived directly from the drinking water regulation. In the case of large-scale plants (> 400 liters of storage or> 3 liters of water from the storage tank to the final tap), the water is atomized (eg showers) every year or every three years the water is examined for legionella.

What requirements does the VDI / DVGW 6023 require for the qualification of the personnel for drinking water installations?

The VDI / DVGW 6023 requires an additional qualification in the form of hygiene training from everyone who works on drinking water installations, in addition to the basic professional qualification. A distinction is made between a drinking water hygiene training course, type B (1 day), drinking water hygiene training for type A (2 days) and a briefing (for operators). The hygienic training type B is for all persons who erect and maintain drinking water installations. Persons performing planning tasks, carrying out responsible tasks or carrying out auditing activities require hygienic training according to type A.

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