Drinking water is the most important foodstuff in Germany. Protecting its quality is one of the top priority tasks for the water industry and for water researchers.
Drinking water is the most important foodstuff in Germany. Protecting its quality is one of the top priority tasks for the water industry and for water researchers. New research methods offer enhanced capabilities to detect substances and microorganisms. They provide better insights into the quality of drinking water on the one hand, but on the other they also present new questions about e.g. the relevance of the newly discovered substances and microorganisms, and about how to deal with them.
The persistence, mobility and toxicity of these substances and microorganisms need to be evaluated (PMT criteria), and more advanced analysis methods are required to demonstrate their presence. Setting up and managing a database that contains information and guidance is an indispensable basis for well-informed evaluation; last but not least, standards taking into account the specific water supply requirements are required for the approval of substances.
The scope of screening should be limited in order to manage the vast number of newly found substances, e.g. by analysing only regionally present substances. Specific minimisation and avoidance strategies can make sense for a variety of groups of substances.
Clean resources constitute the basis for supplying high-quality drinking water. Resource management and protection are crucial in this context, but conflicting targets have been persisting for decades in the form of problems caused by the pollution of groundwater with nitrate. It is difficult to make other players accept demands for protection, however; furthermore, new challenges have surfaced as more people move to live in cities and as resource-use conflicts intensify in metropolitan areas.
These and similar conflicts may be resolved by guidelines that combine the technical and legal sectors and offer suitable operationalisation proposals. Analysing case examples and identifying procedural weaknesses will yield the necessary knowledge; any findings gained can be used for developing a risk management strategy.
New substances in the environment mean that water suppliers have to meet new requirements. Likewise, they are faced with new problems relating to microbiology and/or molecular biology. The utilities therefore have to characterise their raw water quality and, at the same time, ensure sufficient transparency for their customers.
Polar substances and contaminants such as microplastics, antibiotic resistance genes or algal toxins call for special attention during the water treatment process. Both the chemical composition of these substances as well as the microbiological and biological methods of analysis are relevant. In this context, however, there is a dearth of knowledge about the impact that energy saving measures and lower temperatures may have on hot water systems.
The water industry envisages as its ultimate goal a durable drinking water installation that has the lowest possible impact on drinking water quality. This poses further challenges like e.g. the limited understanding of certain processes caused by some corrosion phenomena; forecasting and assessing the stability of new materials; effects brought about by changes in water quality (e. g. by water changes) and a lack of transparency and available data about the use and suitability of materials.