A non-pumping well used for observing the elevation of the water table or piezometric surface.
A shaft or borehole used for observing groundwater head or quality.
a well located some distance from a pumping well which is used to measure changes in water levels during an applied aquifer stress.
Non-pumping well used primarily for observing the elevation of the water table or the piezometric pressure; also to obtain water-quality samples.
A well drilled into an aquifer for the purpose of obtaining water level, water temperature, or water quality data.