Delineation of the coastal aquifer of Israel based on repetitive analysis of 14C and tritium

In most cases, based on the presence of detectable levels of tritium throughout most of the aquifer, the groundwater in the coastal aquifer was determined to contain a young component with a transit time of less than forty years. However, the 14C levels of most of the same groundwater samples were found to be lower than atmospheric levels (34-102 vs. >100 pMC), probably due to water-rock interactions rather than decay due to old age. Some older waters exist in the lower sub-aquifers of the deeper wells (120-140 m) where both lower 14C values (42-69 pMC) and very low levels of tritium were found (0.1-0.7 TU).