Suitability of Environmental Tracers as groundwater dating tools in the next decade

In the last decade a large and various set of groundwater modelling tools were developed and provide wide range of applications. In contrast, the number of tools for field studies remains limited. One of the tools are Environmental Tracers: substances of natural or anthropogenic origin which enter the groundwater system and were traced on their way to the discharge zone. Methods to interpret the tracer concentrations and how groundwater dynamics could be derived were published also in textbooks by now. One parameter to describe groundwater dynamics is residence time, age or flow velocity. All these terms are interchangeable.

Here, I will present an overview on applied Environmental Tracers to determine groundwater ages and assess their current limitation. Specially, I will make some predictions on the applicability for the near future. This includes some estimates about the concentration changes for the input of the tracers for younger groundwater and the consequences for reliability of the derived ages.

Also, I give an overview on the state of the measurement capacities and the possible development. It will be estimated how the analytical errors affect the ages. These constraints must be recognized for planning of field studies for groundwater age determination.