Radiocarbon Dating of Ground Water

Radiocarbon dating of ground water is used in combination with the primary measurements of classical hydrological and chemical analyses. Radiocarbon dating will produce the best results when it involves multiple measurements or sequential sampling. The most useful data come from these comparisons and not from absolute ages. In the case of multiple measurements, the apparent ages of the ground water taken from pumps that are at varying distances from the aquifer outcrop could be a means of verifying flow rate and also indicate situations of overpumping. In the case of sequential sampling of an individual well every six or twelve months, any changes in the apparent age of the water are plotted versus time. In particular, if the age of the water is getting younger with time, it would usually be due to a drawing-down of the more shallow water layers. Radiocarbon dating has the potential of giving advance notice of impending contamination by surface layer waters.