Map showing the difference between the potentiometric surfaces of the Magothy Aquifer of September 1975 and September 1982 in southern Maryland

A map was prepared that shows the net change in the potentiometric surface of the Magothy aquifer in southern Maryland from September 1975 to September 1982. The map is based on measurements from a network of 55 observation wells. During the 8-year period, the potentiometric surface was (1) lowered by at least a few feet throughout the entire southern Maryland area , (2) lowered by at least 10 feet in the southern half of the area, and (3) lowered by 30 to 40 feet in most of northern Charles County. The network of observation wells was developed as part of the cooperative program between the U.S. Geological Survey, the Maryland Geological Survey, and the Maryland Energy Administration. (USGS)