Oct 2, 2026 - Foods
Microbiological self-monitoring of drinking water: What should food companies consider?
Drinking water plays an important role in many food businesses – whether as an ingredient, in the production and processing of food, or in cleaning processes. Accordingly, microbiological testing of water is often part of internal operational controls.
In practice the question repeatedly arises: Do these tests necessarily have to be carried out according to the requirements of the Drinking Water Ordinance?
This is precisely where a differentiated approach is worthwhile.
Not every water sample is subject to the same requirements
Food businesses must ensure that the water used in the production and handling of food has the required quality. At the same time, this does not automatically mean that every internal operational control is fully subject to the testing obligations of the Drinking Water Ordinance. Article Lebensmittelkontrolleur…
Among other things, it is crucial whether a food business operates its own water supply system, for example its own well, or obtains drinking water from the public water supply.
In food businesses without their own water supply system, tests from the building's drinking water installation can, for example, represent voluntary internal controls as part of operational quality assurance. For these, not all specific requirements of the Drinking Water Ordinance regarding sampling and testing automatically apply. Article Lebensmittelkontrolleur…
However, this does not mean that a professional procedure can be dispensed with in such tests. Samples must be taken correctly, protected from contamination, transported appropriately and microbiologically analysed. The specific procedure should be guided by the intended use of the water and the respective operational situation. Article Lebensmittelkontrolleur…
What does this mean for operational practice?
The distinction between legally required tests and internal operational controls can have significant implications for the requirements regarding sampling, scope of testing and the evaluation of results.
There are also important specifics when assessing microbiological test results. For example, for colony counts at 22 °C and 36 °C when applying DIN EN ISO 6222, a numerically defined assessment value is not prescribed in every case. Article Lebensmittelkontrolleur…
A separate consideration is also required for legionella testing. Here too, an obligation to test under the Drinking Water Ordinance depends on the specific operational circumstances and the use of the water. Article Lebensmittelkontrolleur…
Specialist article by Paul Andrei in “Der Lebensmittelkontrolleur”
Paul Andrei, founder and managing director of the BAV Institute and Global Microbiology Manager of the Tentamus Group, deals with these issues in detail in his current specialist article:
In it, Paul Andrei explains, among other things, when the testing obligations of the Drinking Water Ordinance apply, which requirements must be observed for internal operational controls, and which particularities play a role in the evaluation of microbiological results.
Would you like to learn more? You can find the full article in the current issue 3/2026 of “Der Lebensmittelkontrolleur”.