Chlorofluorocarbons and 3H/3He in groundwater -: Applications in tracing and dating young groundwater

Based on the CFC concentration, the fraction of young groundwater in a mixture with old groundwater can be defined if the age of the young component is known. The authors argued that the ratio of [He-3(t)]/[H-3(t)] in a young water is independent of its mixing with old waters. Hence, the H-3-He-3 can be used to determine age of the young groundwater, though mixing with old groundwater may occur. CFC concentrations are susceptible to change by mixing of young and old water. The combination of CFCs and tritium/helium can provide confidential apparent age of the young groundwater and fraction of the young water in the mixture with old groundwater.