Groundwater Age Dating
Information about the age of groundwater can be used to define recharge rates, refine hydrologic models of groundwater systems, predict contamination potential, and estimate the time needed to flush contaminants from ground-water systems. Groundwater age dating also can be used to trace seepage from rivers into ground-water systems, provide diagnostic tools for detection and early warning of leakage from landfills and septic tanks, and to assess susceptibility of water-supply wells to contamination from near-surface sources. For example, groundwater discharging from the spring on this page was analyzed by tritium dating to be older than 20th century atmospheric nuclear explosions ("pre-bomb" water).
Photo: Iron-rich spring in Upper Animas River watershed showing rimstone dams and subaqueous formations created by chemotrophic bacteria.