ASTM D5269-15 PDF Download

ASTM D5269-15 standard provides an analytical procedure for determining the transmissivity of a confined aquifer. The test method is used to analyze data on the recovery of water levels following pumping or injection of water to or from a control well at a constant rate.

The standard specifies several assumptions that must be met for the test method to be valid. These assumptions include:

1) The well discharges at a constant rate or at steps of constant rate.

2) The well is of infinitesimal diameter and open through the full thickness of the aquifer.

3) The nonleaky aquifer is homogeneous, isotropic, and extensive in area.

4) Discharge from the well is derived exclusively from storage in the aquifer.

5) The geometry of the aquifer and well are shown in Figure 1.

The standard also discusses the implications of these assumptions. For example, it states that the assumptions imply radial flow, and any vertical flow components should be negligible. It also mentions that the storage in the control well may affect drawdown measurements in the early part of the test.

The standard further clarifies that the Theis recovery method can be applied to unconfined aquifers under certain conditions, such as small drawdown compared with the saturated thickness of the aquifer and small effects of delayed gravity yield.

It is important to note that the quality of the results obtained through this standard depends on the competence of the personnel performing the test, as well as the suitability of the equipment and facilities used. Compliance with Practice D3740 does not guarantee reliable results, as many factors can affect the reliability of the tests.