ABSTRACT
The frequency of well measurements must be established in the wellfield monitoring plan. Since the hydrogeologic information used to design any given wellfield is always incomplete or inexact to some degree, there may be a necessity to adjust the initial wellfield design as operating data are collected. When the natural variation in hydraulic conductivity is localized, an adjustment may be required in the pumping rate of a single production well or perhaps a few wells. Once a problem has been detected in the monitoring well system, it is very important to diagnose the cause of the problem and modify the wellfield operation as needed. Monitoring wells should be used to measure the potentiometric pressure and the water quality in the production aquifer and perhaps in bordering aquifers. Any significant change in the potentiometric pressure or water quality in a monitoring well should be immediately verified and reported.
