Environmental Engineering Reference
In-Depth Information
Fig. 3.41 Typical installation to quantify horizontal and vertical hydraulic gradient, seepage rate,
and hydraulic conductivity
wetland and the other constructed to indicate hydraulic head at some point beneath
the water table (Fig.
3.41
). Although both can be considered as piezometers, we will
refer to the first as a water-table well.
Water-Table Well Installation
A water-table well is designed to indicate the elevation of the top of the saturated
portion of the sediments where pressure head is equal to atmospheric pressure (the
water table). Installation of a water-table monitoring well can be simple and
inexpensive if the land surface slopes gently away from the wetland edge, in
which case the vertical distance from land surface to the water table is usually
small. In these shallow, near-shore margins a monitoring well can usually be
installed by hand, precluding the need for a large, mechanical drill rig. Such is
