Map of estimated mean groundwater ages in the south Atlantic and Gulf

The USGS recently completed a study to estimate groundwater age in the south Atlantic and Gulf Coast principal aquifer systems. Groundwater was relatively old across the aquifer systems, with estimated ages ranging from 17 years to greater than 50,000 years, and a mean age of about 30,000 years. Estimates of groundwater age were related to hydrogeology, with increasing groundwater ages associated with greater depth, confinement, and distance from the recharge zone. These groundwater age distributions were then used to calculate metrics of susceptibility to land surface and geogenic contamination sources, which can be used by resource managers and policy makers to inform assessments of well susceptibility to contamination.

This map presents estimated mean groundwater ages from principal aquifer study well networks in the south Atlantic and Gulf Coast aquifer systems, USA. Source: Figure 7a, Solder, 2020