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Environmental Radioactivity - Medicine - Occupational Radiation Protection - Nuclear Hazards Defence

Ionisierende Strahlung

Guidelines create basis for safeguarding the quality of drinking water

  • The "Guidelines for the analysis and assessment of radioactive substances in drinking water by implementing the Drinking Water Ordinance" (Leitfaden zur Untersuchung und Bewertung von radioaktiven Stoffen im Trinkwasser bei der Umsetzung der Trinkwasserverordnung, in German only) published in February 2017 form the basis for the comprehensive testing of water quality with respect to radioactivity-related parameters.
  • According to the Drinking Water Ordinance, large water suppliers are obliged by the end of 2019 to undertake analysis of the concentration of radionuclides in drinking water. The new guidelines provide a uniform basis for this.
  • The basis is a European directive, which came into effect in 2013 and which was adopted into the Drinking Water Ordinance in 2015 (in German only). In 2009, the Federal Office for Radiation Protection (BfS) performed a comprehensive and systematic analysis to create a technical basis that established requirements for the monitoring of natural radioactivity in drinking water within the context of drinking water legislation.

The revised guidelines on the analysis and assessment of radioactive substances in drinking water create the basis for the long-term safety of drinking water. They standardise both the analysis and its implementation by the supervisory authority. They came into effect under the careful guidance of the BfS and replaced an earlier version from 2012.

According to the Drinking Water Ordinance, large water suppliers are obliged by the end of 2019 to undertake analysis of the concentration of radionuclides in drinking water. The guidelines contibute to the consistent understanding of the legal provisions.

The Federal Ministry for the Environment, Conservation and Nuclear Safety (BMU), the Federal Office for Radiation Protection (BfS), the Federal Ministry for Health (BMG), the Federal Environment Agency (UBA), the competent state authority, the German Technical and Scientific Association for Gas and Water (DVGW) and the Federal Association of the Energy and Water Industry (BDEW) recommend the application of the new drinking water guidelines. The guidelines correspond to the latest scientific knowledge. This is to ensure the ongoing high quality of drinking water in Germany.

Development of the guidelines: First BfS study in 2009, European regulations and ordinances

The first comprehensive and systematic analysis to assess the radioactivity in drinking water was pulished by the Federal Office for Radiation Protection in 2009 in the study "Radiation exposure through natural radionuclides in drinking water in the Federal Republic of Germany" (in German only).

The study included large areas of the country and experts analysed 582 drinking water samples. In urban areas, these came overwhelmingly from large water supply facilities, which sometimes provided drinking water for several million people. In addition, targeted samples from water supply facilities in areas with increased natural radioactivity were analysed from the states of Bavaria, Saxony, Baden-Wuerttemberg, Thuringia, Rhineland-Palatinate and Saxony-Anhalt. Because of this approach, the data acquired is representative for the purpose of the task.

Result: radiation exposure for people through radionuclides in drinking water is low

The study showed that exposure through natural radionuclides in drinking water in Germany can be classified overall as low. According to this, adults are exposed to radiation of around 0.009 millisieverts per year because of radionuclides in drinking water. For infants this value is on average around 0.05 millisieverts. By comparison, the natural radiation level to which the population as a whole is exposed per year is around 2.1 millisieverts. Of course, depending on the properties of the subsoil, drinking water can show an increased natural radionuclide content.

Between 2009 and 2012, an interdisciplinary working group led by the BfS and consisting of ministries, radioactivity measuring institutions of the Laender, analytical laboratories and drinking water associations developed a guide for the analysis and assessment of radioactivity in drinking water and put the existing requirements into concrete terms on the recommended basis.

With the 2013/51/EURATOM guideline (in German only) published in 2013, the Council of the European Union established requirements to protect the health of the population as regards radioactivity in drinking water and obliged EU members states to implement the guideline in their national legislation by 28 November 2015. In Germany, the implementation was effected with the third regulation to amend the Drinking Water Ordinance (TrinkwV) dated 18 November 2015.

Requirements for practical implementation

The guideline states which requirements the investigative bodies must fulfil when taking samples – for example what investigative procedures to apply or how frequently samples should be taken. For certain radionuclides, the ordinance also indicates reference activity concentrations with which the measurement results can be correlated.

These instruments form the basis for imposing measures in individual cases to reduce radionuclide concentrations in drinking water and therefore for ensuring the quality of drinking water and protecting human health.

The analyses and assessments of parameters relating to radioactivity in drinking water that are set out in the guidelines for the implementation of the Drinking Water Ordinance may be implemented only by the relevant competent authority. Accreditation as an analysis site by the competent state authority is awarded to laboratories that are accredited for analysis under the Drinking Water Ordinance. It is also possible that laboratories can be accredited for the analysis only of individual parameters. The requirements for the accreditation of analysis sites can be found on the Dakks website.

One quality assurance measure for accredited laboratories is successful participation in ring trials. These are implemented for the determination of natural radionuclides in drinking water, for example by the Federal Office for Radiation Protection (BfS) usually over a period of 24 months. This is to ensure the ongoing high quality of drinking water in Germany.

State of 2018.07.03

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