In Europe and Germany administrative regulations exist for the surveillance of the Total Indicative Dose of water supplied for human consumption. This parameter, which can not be analysed directly, has to be calculated using nuclide specific activity concentrations, age-specific dose conversion factors and consumption rates. Available calculation methods differ regarding the used radionuclides, consumption rates and whether they use age specific dose conversion factors or not. In Germany, administrative guidelines for the determination of the Total Ingestion Dose are still not available. From a large number of water sample analyses, a graded practical concept for the determination of the ingestion dose is derived, which considers radiological, analytical and hydrochemical aspects as well. Finally, it is suggested to consider mineral water in the same manner as drinking water.