Appendix F.Piezometer Pressure and Water Level

Frequently, when using a dip meter to check water levels in an open well, it happens that the water level, computed from a piezometer reading taken at the bottom of the well, does not agree with the water level measured directly by the dip meter. This will happen when the specific gravity of the water is not 1 gm/cc, the water is brackish or muddy, or both. It will also occur when there is a flow of water up or down the borehole. In addition, if the piezometer is removed to make room for the dip meter, the volume of the piezometer and cable displaces an equal volume of water, which can cause changes of the water level in a small diameter well.