Geology topics
Publications and source records attributed to F. K. Mack.
Thr potentiometric map is highlighted with indications concerning: (1) outcrop areas of the Aquia aquifer; (2) the potentiometric contour of the aquifer; (3) observation and/or supply wells yielding < 10,000 gallons/day (gpd); and (4) other supply wells with yields > 10,000 gpd. (Lantz-PTT)
The potentiometric map is highlighted with indications concerning: (1) outcrop areas of the Magothy aquifer; (2) the potentiometric contour of the aquifer; (3) observation and/or supply wells yielding < 10,000 gallons/day (gpd); and (4) other supply wells with yields > 10,000 gpd. (Lantz-PTT)
The potentiometric map is highlighted with indications concerning: (1) outcrop areas of the Magothy aquifer; (2) the approximate location of the line of equal difference between the potentiometric surface in fall 1975 and fall 1986; (3) observation and/or supply wells yielding < 10,000 gallons/day (gpd); and (4) other supply wells with yields > 10,000 gpd. (Lantz-PTT)
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.
The map is based on measurements from a network of 83 observation wells cased to the Magothy aquifer. Highest levels of the potentiometric surface, 59 to 60 feet above sea level, were measured near the outcrop-subcrop of the aquifer in topographically high areas of Anne Arundel and Prince Georges Counties. The surface slopes to the southeast to above sea level along much of the western shore of Chesapeake Bay. Three separate, distinct, and extensive cones of depression have developed in the potentiometric surface around the well fields of the city of Annapolis-Broadneck Peninsula area, town of Waldorf, and Chalk Point. Several square miles of each cone are below sea level, and, in some areas at Chalk Point and Waldorf, the cone is 40 to 50 feet below sea level. The network of wells was developed as part of the cooperative program between the U.S. Geological Survey, the Maryland Geological Survey, and the Maryland Energy and Coastal Zone Administration. (USGS)
A map has been prepared that shows the net differences between two sets of water-level measurements made in 67 observations wells over a six-year period. One set of measurements was made in 1975, a relatively wet year, and the other set of measurements was made in 1981, a relatively dry year. The map shows that, except for a small area near the Annapolis well field where Magothy production wells were temporarily shut down, the potentiometric surface of 1981, compared with the potentiometric surface 1975, was: lower throughout the entire area; lower by at least 10 feet in the southwestern third of the area; lower by 30 to 40 feet in parts of northern Charles County , where pumping rates increased from an average of one million gallons per day (Mgal/d) in 1975 to 2.5 Mgal/d in 1981. (USGS)
A brief study of the Atlantic Coastal Plain aquifers in the vicinity of the Washington, D.C., metropolitan area was made, using available data, to estimate the water-supply potential of these aquifers and to determine the possibility of developing an emergency water supply during droughts. Assuming that the data available are representative, the study indicates that the water-supply potential of these aquifers, within an assumed 30-mile radius of Washington, D.C., is about 170 million gallons per day. That is, these aquifers, which are now furnishing an estimated 60 million gallons per day, could be developed to supply an additional 110 million gallons per day on a continuous basis. This quantity might be even larger if a significant amount of water is derived from leakage through finer grained confining beds, but further studies would be necessary to determine the amount of leakage and the long-term effects of large-scale continuous use. Furthermore, under intermittent pumping conditions, an assumed emergency supply of 100 million gallons per day could probably be developed from well fields within a 30-mile radius of Washington. An exploration and testing program would be necessary to assess the reliability of these preliminary estimates.
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Explore the source record for details and available documents.