In Germany, the indicator principle is used for routine monitoring of drinking water for hygienic contaminations. This concept reaches its limits in some places, so that the hygienic safety of drinking water should be guaranteed by other methodical procedures.
In Germany, the indicator principle is used for routine monitoring of drinking water for hygienic contamination. The potential presence of fecal pathogens is indicated by the detection of fecal indicator organisms. The pathogens themselves are not measured.
This concept has prevailed for over 100 years and is also anchored in the German Drinking Water Directive.
In recent decades, however, numerous novel water-associated viral and parasitic pathogens have come to the fore worldwide, some of which have led to disease outbreaks even in technically highly developed countries. The concept of indicators thus reaches its limits in some places.
As an alternative, a quantitative microbial risk assessment (QMR) for water supply systems has been recommended by the WHO in the "Guidelines for Drinking-water Quality" for several years. After the mandatory introduction of the risk-based approach in the new Drinking Water Directive, such an application is also increasingly discussed in Germany. In the Netherlands, the implementation of a QMR has been a legal requirement since 2001.
The aim of this project is to examine whether the hygienic safety of drinking water should be guaranteed by other methodological approaches such as a QMR. For this purpose, the different methodological assessment approaches will be compiled and compared. Finally, a concept paper on the future of quantitative microbial risk assessment will be prepared, reflecting the current state of discussion in Germany.
For example, the experiences from the Netherlands were presented in an online workshop on 22.05.2023.
As a central element of the project, a workshop on the topic was held on 06.10.2023 at the TZW in Karlsruhe, where the issues were discussed in detail with all stakeholders involved.