Preliminary map showing the difference between the potentiometric surfaces of the Aquia aquifer of April 1979 and September 1982 in southern Maryland

A map was prepared that shows the net change in the potentiometric surface of the Aquia aquifer in southern Maryland between April 1979 and September 1983. During this period, the potentiometric surface declined (1) at least a few feet throughout the entire southern Maryland area, and (2) more than 10 feet in the eastern Charles County area and in a few scattered localized areas. The network of observation wells was part of the cooperative program between the U.S. Geological Survey, the Maryland Geological Survey, and the Maryland Energy Administration.