Determination of groundwater age using environmental isotopes - methodological remarks

Groundwater age plays an important role in both development and management of groundwater resources. This is particularly true for groundwater systems being exploitedfor drinking water purposes and subject to anthropogenic stress. Environmental isotopes play a vital role in quantifying time scales of groundwater flow, ranging from fraction of a year to millions of years. Over the past several decades a large number of groundwater age indicators have been proposed. Apart of radioactive isotopes, also stable isotopes of water, isotopes of noble gases and anthropogenic trace substances present in the atmosphere have been usedfor this purpose. This work is focusing on methodological aspects of groundwater age determinations using tritium, radiocarbon and stable isotope composition of water. The discussion is based on a rich material available after several decades of application of environmental isotope techniques in groundwater studies in Poland