Working Report, 11/2006 – Radioactive isotopes in Danish drinking water

Radioactive isotopes in Danish drinking water

Preface

This project for investigation of radioactivity in drinking water shall be seen as a documentation of the content of radioactivity in Danish drinking water. During revision of the Drinking Water Directive of the Council of the European Union (98/83/EU) radioactivity was included as a new parameter.

Most of the Danish drinking water (about 99%) is obtained from groundwater for what reason radioactivity in Danish drinking water is due mainly to naturally occurring radionuclides.

As the risk for high levels of radioactivity in the Danish Underground was assessed to be very low due to the information on the geological underground, the Danish Environmental Protection Agency (EPA) decided to do a national study on selected drinking waters. Selection criteria were:

Important abstraction areas for the largest water supplies supplemented with
Supplies distributed reasonably well over the country and
Areas where the layers in the ground or the bedrock could indicate a higher risk.

The plan for the investigation was discussed and decided in co-operation between the Danish EPA, the National Institute of Radiation Hygiene (SIS) and Risø National Laboratory. The Geological Survey of Denmark and Greenland (GEUS) were consulted to help by selection of useful sampling point in areas with possibly increased levels of radioactivity.

All the water works selected to take part in this investigation have responded very positively and have been a great help for collecting the many samples. The Danish EPA will hereby thank the water works for their willingness and great help.

The project was carried out by Risø National Laboratory and followed by a Steering Committee with the following members:

Janne Forslund, Danish EPA (chairman)
Martin Skriver, Danish EPA
Kaare Ulbak, National Institute of Radiation Hygiene (SIS)
Carsten Israelson, National Institute of Radiation Hygiene (SIS)
Peter Gravesen, Geological Survey of Denmark and Greenland (GEUS)
Sven P. Nielsen, Risø National Laboratory (Project leader)
Per Roos, Risø National Laboratory