The “Trinkwasserverordnung” sets limit values for various microorganisms, including Escherichia coli (E. coli): An indicator of faecal contamination. Coliform bacteria: General indicators of water quality. Enterococci: Other indicators of faecal contamination. Clostridium perfringens (including spores): Indicators of past faecal contamination. Legionella: Bacteria that thrive in warm water and can cause Legionnaires' disease.

A microbiological drinking water analysis according to the German “Trinkwasserverordnung” (TrinkwV) tests drinking water for the presence of harmful microorganisms to ensure that the water meets legal requirements and is safe for human consumption.

The frequency of testing depends on the type of water supply: Public water supplies: regular and frequent testing in accordance with the requirements of the “Trinkwasserverordnung”. Private households with their own water supply (e.g. well water): At least once a year. Rented accommodation and public buildings: Depending on local regulations, often at least once a year.

Faecal contamination: From sewage discharges, leaking sewers or flooding. Natural sources: Surface water entering wells or drinking water pipes. Internal contamination: Biofilm formation in poorly maintained pipes and tanks.

Use a sterile sample container: The sample container should be sterile to avoid contamination. Wash your hands: Wash your hands thoroughly before taking a sample. Let the water run: Run the water for at least 2-3 minutes to flush any standing water from the pipes. Collect the sample: Hold the sterile container under the stream of water and fill without touching the rim or lid. Transport: The sample should be transported to the laboratory as quickly as possible and kept cool.

Informing consumers: Consumers must be informed immediately of the contamination. Remedial action: Immediate measures to eliminate the contamination and ensure water quality, e.g. disinfection of pipes. Follow-up testing: Repeated tests to ensure that the contamination has been eliminated and the water is back to legal requirements.

Certified and accredited laboratories working in accordance with the Drinking Water Ordinance are responsible for carrying out the microbiological analyses. These laboratories guarantee accurate and reliable results.

The legal basis is the “Trinkwasserverordnung”, which regulates the quality requirements for drinking water in Germany. This ordinance is based on the EU Drinking Water Directive and defines the limit values for microorganisms and other parameters that drinking water must meet.

Further information can be found on the websites of: Federal Ministry of Health (BMG) Federal Environment Agency (UBA) Regional health authorities Certified water laboratories