Cooley and Case Solution for Leaky Aquifers

Well-aquifer configuration for Cooley and Case (1973) pumping test solution for a leaky confined aquifer with a water-table aquitard

A mathematical solution by Cooley and Case (1973) is useful for determining the hydraulic properties (transmissivity, storativity and leakage parameters) of a leaky confined aquifer with a water-table aquitard. Analysis involves matching the Cooley and Case solution to drawdown data collected during a constant- or variable-rate pumping test.

AQTESOLV provides visual and automatic methods for matching the Cooley and Case solution to pumping test data. This easy-to-use and intuitive software promotes rapid and accurate determination of aquifer properties.

Assumptions

The following assumptions apply to the use of the Cooley and Case solution:

  • aquifer has infinite areal extent
  • aquifer is homogeneous, isotropic and of uniform thickness
  • potentiometric surface is initially horizontal
  • aquifer is confined
  • flow is unsteady
  • wells are fully penetrating
  • water is released instantaneously from storage with decline of hydraulic head
  • diameter of control well is very small so that storage in the well can be neglected
  • confining bed has infinite areal extent, uniform vertical hydraulic conductivity, storage coefficient, specific yield and thickness
  • flow is vertical in the aquitard

Solution
Options

provides the following options for the Cooley and Case solution:

  • constant or variable pumping rate with recovery
  • multiple pumping wells
  • multiple observation wells
  • boundaries

References

Cooley, R.L. and C.M. Case, 1973. Effect of a water table aquitard on drawdown in an underlying pumped aquifer, Water Resources Research, vol. 9, no. 2, pp. 434-447.