The hydrochemistry and age of the water in the Milk River aquifer, Alberta, Canada

Abstract

The Milk River aquifer system in Alberta, Canada, was studied to develop age-dating techniques for old ground water. A steadystate flow model used to calculate hydrodynamic ages of the ground water and ¹⁴C concentrations in the water were used to calculate ages for comparison. The results were compared with ³⁶Cl-predicted ages of the same aquifer. The ages predicted with the flow model showed a progression of increasing age from zero at the Milk River sandstone outcrop near the United States—Canadian border to 500,000 years near Taber, a town about 60 miles northwest of the outcrop. A sensitivity analysis on the input parameters to the flow model indicated that the predicted age of the water is most sensitive to changes in sandstone porosity and the vertical permeability of the shales and clays overlying and underlying the sandstone aquifer.