Potential effects of regional pumpage on groundwater age distribution

Water Resources Research
By:  and 



Groundwater ages estimated from environmental tracers can help calibrate groundwater flow models. Groundwater age represents a mixture of traveltimes, with the distribution of ages determined by the detailed structure of the flow field, which can be prone to significant transient variability. Effects of pumping on age distribution were assessed using direct age simulation in a hypothetical layered aquifer system. A steady state predevelopment age distribution was computed first. A well field was then introduced, and pumpage caused leakage into the confined aquifer of older water from an overlying confining unit. Large changes in simulated groundwater ages occurred in both the aquifer and the confining unit at high pumping rates, and the effects propagated a substantial distance downgradient from the wells. The range and variance of ages contributing to the well increased substantially during pumping. The results suggest that the groundwater age distribution in developed aquifers may be affected by transient leakage from low‐permeability material, such as confining units, under certain hydrogeologic conditions.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Potential effects of regional pumpage on groundwater age distribution
Series title Water Resources Research
DOI 10.1029/2006WR004865
Volume 43
Issue 6
Year Published 2007
Language English
Publisher American Geophysical Union
Contributing office(s) Toxic Substances Hydrology Program
Description W06418; 17 p.