The determination of radon in a number of groundwater and finished drinking water samples from the Dutch provinces Overijssel and Limburg show a low level of radon. A comparison of the data with an earlier campaign in 1995 shows that radon-222 activity concentrations in water samples in the Netherlands are at a constant and low level.

Measurements were conducted in the framework of the Dutch drinking water monitoring programme. In groundwater the radon-222 activity concentration ranges from 1.6 – 16.7 Bq/l, and in finished drinking water from 0.2 – 9.5 Bq/l. Following Euratom Directive (2013/51/EC) it is not necessary to imply radon-222 in the Dutch drinking water monitoring programme if it is clearly demonstrated that all data are well below accepted levels.