AssumptionsLeaky Aquifer:

Drawdown (s_W) in the control well is constant,

Well is infinitesimal diameter and fully penetrates aquifer,

The aquifer is homogeneous, isotropic, and areally extensive, and

The control well is 100 % efficient.

AssumptionsNonleaky Aquifer:

Drawdown (s_W) in the control well is constant,

Well is infinitesimal diameter and fully penetrates aquifer,

The aquifer is homogeneous, isotropic, and areally extensive,

Discharge from the well is derived exclusively from storage in the nonleaky aquifer, and

The control well is 100 % efficient.

Implications of Assumptions:

The assumptions are applicable to confined aquifers and fully penetrating control wells. However, this test method may be applied to partially penetrating wells where the method may provide an estimate of hydraulic conductivity for the aquifer adjacent to the open interval of the well if the horizontal hydraulic conductivity is significantly greater than the vertical hydraulic conductivity.

Values obtained for storage coefficient are less reliable than the values calculated for transmissivity. Storage coefficient values calculated from control well data are not reliable.

1.1 This test method covers an analytical solution for determining transmissivity and storage coefficient of a leaky or nonleaky confined aquifer. It is used to analyze data on the flow rate from a control well while a constant head is maintained in the well.

1.2 This analytical procedure is used in conjunction with the field procedure in Practice D5786.

1.3 Limitations—The limitations of this technique for the determination of hydraulic properties of aquifers are primarily related to the correspondence between field situation and the simplifying assumption of the solution.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.