David C. Andreasen Andrew W. Staley Stephen E. Curtin 2009 This report presents a map showing the potentiometric surface of the Magothy aquifer in the Magothy Formation of Late Cretaceous age in Southern Maryland during September 2007. The map is based on water-level measurements in 69 wells. The highest measured water level was 85 feet above sea level near the northern boundary and outcrop area of the aquifer in the north-central part of Anne Arundel County. The potentiometric surface declined towards the south. Local gradients were directed toward the center of a cone of depression in the Waldorf area that developed in response to pumping. Measured ground-water levels were as low as 90 feet below sea level in the Waldorf area. application/pdf 10.3133/ofr20091082 en U.S. Geological Survey Potentiometric Surface of the Magothy Aquifer in Southern Maryland, September 2007 reports