Pg. Cook et Dk. Solomon, RECENT ADVANCES IN DATING YOUNG GROUNDWATER - CHLOROFLUOROCARBONS, H-3 HE-3 AND KR-85/, Journal of hydrology, 191(1-4), 1997, pp. 245-265
Chlorofluorocarbons, H-3/He-3 and Kr-85 are tracers of atmospheric ori
gin that can be used to date groundwater over periods from 0 to 40 yea
rs. In suitable aquifers, measured groundwater ages can be used to est
imate groundwater flow paths, and vertical and horizontal flow velocit
ies. In simple, piston flow systems they can be used to estimate groun
dwater recharge rates with an accuracy of 20% or less, better than can
be achieved with traditional hydraulic-based methods. Groundwater dat
ing methods have also been used to reconstruct past releases of contam
inants to aquifers.