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David C. Andreasen

Publications and source records attributed to David C. Andreasen.

At least 37 records · Page 2Linked to original sources
USGS2009

The Difference Between the Potentiometric Surfaces of the Magothy Aquifer in Southern Maryland, September 1975 and September 2007

This report presents a map showing the change in the potentiometric surface of the Magothy aquifer in the Magothy Formation of Late Cretaceous age in Southern Maryland for September 1975 and September 2007. The map, based on water-level measurements in 51 wells, shows that during the 32-year period, the potentiometric surface had no change at the outcrop area, which is in the northernmost part of the study area, but declined 90 feet at Waldorf. Waldorf is located near the southwesternmost part of the study area, and approaches the downdip boundary of the aquifer.

Open-File Report↗
USGS2009

Potentiometric Surface of the Upper Patapsco Aquifer in Southern Maryland, September 2007

This report presents a map showing the potentiometric surface of the upper Patapsco aquifer in the Patapsco Formation of Early Cretaceous age in Southern Maryland during September 2007. The map is based on water-level measurements in 50 wells. The highest measured water level was 120 feet above sea level near the northern boundary and outcrop area of the aquifer in northern Anne Arundel County. From this area, the potentiometric surface declined to the south toward a well field in the Annapolis-Arnold area, and from all directions toward four cones of depression. These cones are located in the Waldorf-La Plata area, Chalk Point-Prince Frederick area, Swan Point subdivision in southern Charles County, and the Lexington Park-St. Inigoes area. The lowest measured ground-water level was 44 feet below sea level at Arnold, 106 feet below sea level south of Waldorf, 54 feet below sea level at Swan Point, 59 feet below sea level at Chalk Point, and 58 feet below sea level at Lexington Park.

Open-File Report↗
USGS2009

The Difference Between the Potentiometric Surfaces of the Upper Patapsco Aquifer in Southern Maryland, September 1990 and September 2007

This report presents a map showing the change in the potentiometric surface of the upper Patapsco aquifer in the Patapsco Formation of Early Cretaceous age in Southern Maryland for September 1990 and September 2007. The map, based on water-level measurements in 33 wells, shows that during the 17-year period, the change in the potentiometric surface ranged from zero at the edge of the outcrop area in northern Anne Arundel County to a decline of 28 feet at Crofton Meadows, 38 feet at Arnold, 36 feet at Waldorf, 35 feet at the Chalk Point power plant, and 40 feet at Lexington Park.

Open-File Report↗
USGS2009

Potentiometric Surface of the Lower Patapsco Aquifer in Southern Maryland, September 2007

This report presents a map showing the potentiometric surface of the lower Patapsco aquifer in the Patapsco Formation of Early Cretaceous age in Southern Maryland during September 2007. The map is based on water-level measurements in 65 wells. The highest measured water level was 111 feet above sea level near the northwestern boundary and outcrop area of the aquifer in northern Prince George's County. From this area, the potentiometric surface declined towards well fields at Severndale and Arnold. The measured ground-water levels were 87 feet below sea level at Severndale, and 42 feet below sea level at Arnold. There was also a cone of depression covering a large area in Charles County that includes Waldorf, La Plata, Indian Head, and the Morgantown power plant. The ground-water levels measured were as low as 219 feet below sea level at Waldorf, 187 feet below sea level at La Plata, 106 feet below sea level at Indian Head, and 89 feet below sea level at the Morgantown power plant.

Open-File Report↗
USGS2009

The difference between the potentiometric surfaces of the lower Patapsco aquifer in southern Maryland, September 1990 and September 2007

This report presents a map showing the change in the potentiometric surface of the lower Patapsco aquifer in the Patapsco Formation of Early Cretaceous age in Southern Maryland for September 1990 and September 2007. The map, based on water-level measurements in 45 wells, shows that the change of the potentiometric surface during the 17-year period ranged from increases of 19 feet at Indian Head and 6 feet near the outcrop area in Glen Burnie, to declines of 41 feet at Arnold, 45 feet at Severndale, 68 feet at Crofton Meadows, 77 feet at Waldorf, 76 feet at La Plata, 28 feet at the Morgantown power plant, and 35 feet at the Swan Point subdivision south of Morgantown.

Maryland↗
USGS2009

Potentiometric Surface of the Patuxent Aquifer in Southern Maryland, September 2007

This report presents a map showing the potentiometric surface of the Patuxent aquifer in the Patuxent Formation of Early Cretaceous age in Southern Maryland during September 2007. The map is based on water-level measurements in 41 wells. The highest measured water level was 165 feet above sea level near the northwestern boundary and in the outcrop area of the aquifer in northern Prince George's County. From this area, the potentiometric surface declined south towards well fields at Glen Burnie, Bryans Road, the Morgantown power plant, and the Chalk Point power plant. The measured ground-water levels were 81 feet below sea level at Glen Burnie, 47 feet below sea level southwest of Bryans Road, 27 feet below sea level at the Morgantown power plant, and 24 feet below sea level at the Chalk Point power plant.

Open-File Report↗
USGS2006

Potentiometric surface of the Lower Patapsco Aquifer in southern Maryland, September 2003

This report presents a map showing the potentiometric surface of the Lower Patapsco aquifer in the Patapsco Formation of Lower Cretaceous age in Southern Maryland during September 2003. The map is based on water-level measurements in 66 wells. The highest measured water level was 112 feet above sea level near the northwestern boundary and outcrop area of the aquifer in northern Prince Georges County. From this area, the potentiometric surface declined towards well fields at Severndale, Arnold, and Annapolis. The measured ground-water levels were 86 feet below sea level at Severndale, 41 feet below sea level at Arnold, and 39 feet below sea level a few miles west of Annapolis. There was also a cone of depression covering a large area in Charles County that includes Waldorf, LaPlata, Indian Head, and the Morgantown powerplant. The ground-water levels measured were as low as 165 feet below sea level at Waldorf, 135 feet below sea level at LaPlata, 114 feet below sea level at Indian Head, and 92 feet below sea level at the Morgantown powerplant.

Maryland↗
USGS2005

Potentiometric surface map of the Magothy aquifer in southern Maryland, September, 2003

This report presents a map showing the potentiometric surface of the Magothy aquifer in the Magothy Formation of Upper Cretaceous age in Southern Maryland during September 2002. The map is based on water-level measurements in 79 wells. The highest measured water level was 83 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 and east. Local gradients were directed toward the centers of two cones of depression that developed in response to pumping. These cones of depression were centered around well fields in the Waldorf area and at the Chalk Point power plant. Measured ground-water levels were as low as 81 feet below sea level in the Waldorf area and 75 feet below sea level at Chalk Point.

Maryland↗
USGS2005

The difference between the potentiometric surfaces of the Lower Patapsco Aquifer, September 1990 and September 2003 in Southern Maryland

This report presents a map showing the change in the potentiometric surface of the Lower Patapsco aquifer in the Lower Patapsco Formation of Cretaceous age in Southern Maryland for September 1990 and September 2003. The map, based on water level measurements in 45 wells, shows that the change of the potentiometric surface during the 13- year period ranged from rises of 17 feet at Indian Head and 9 feet near the outcrop area in Glen Burnie, to declines of 40 feet at Arnold, 44 feet at Severndale, 48 feet at Waldorf, 69 feet at LaPlata, and 31 feet at the Morgantown powerplant.

Open-File Report↗
USGS2003

The difference between the potentiometric surfaces of the upper Patapsco aquifer, September 1990 and September 1999 in southern Maryland

This report presents a map showing the change in the potentiometric surface of the Upper Patapsco aquifer in the Upper Patapsco Formation of Cretaceous age in Southern Maryland for September 1990 and September 1999. The map, based on water-level measurements in 37 wells, shows that the potentiometric surface during the 9- year period ranged from a decline of 1 foot in the northernmost part of the study area, which is near the outcrop of the aquifer, to a decline of 22 feet at LaPlata, which is near the southwesternmost part of the study area.

Maryland↗
USGS2003

Potentiometric Surface of the Aquia Aquifer in Southern Maryland, September 2002

This report presents a map showing the potentiometric surface of the Aquia aquifer in the Aquia Formation of Paleocene age in Southern Maryland during September 2002. The map is based on water-level measurements in 94 wells. The highest measured water level was 38 feet above sea level near the northern boundary and outcrop area of the aquifer in the central part of Anne Arundel County, and was below sea level just south of this area and in the remainder of the study area. The hydraulic gradient increased southeastward toward an extensive cone of depression around well fields at Lexington Park and Solomons Island. Another cone of depression occurred in northern Calvert County due to pumpage at and near Chesapeake Beach and North Beach. The water level measured in this area has declined to 55 feet below sea level. The lowest water level measured was 169 feet below sea level at the center of a cone of depression at Lexington Park.

Open-File Report↗
USGS2003

Potentiometric Surface of the Upper Patapsco Aquifer in Southern Maryland, September 2002

This report presents a map showing the potentiometric surface of the Upper Patapsco aquifer in the Patapsco Formation of Lower Cretaceous age in Southern Maryland during September 2002. The map is based on water-level measurements in 50 wells. The highest measured water level was 117 feet above sea level near the northern boundary and outcrop area of the aquifer in northern Anne Arundel County. From this area, the potentiometric surface declined to the southeast toward large well fields in Arnold and Annapolis, and from all directions toward a cone of depression located southwest of Waldorf. The measured ground-water level declined to 36 feet below sea level in Arnold, and to 23 feet below sea level in Annapolis. The lowest water level measured was 136 feet below sea level southwest of Waldorf.

Maryland↗
USGS2003

Potentiometric Surface of the Lower Patapsco Aquifer in Southern Maryland, September 2002

This report presents a map showing the potentiometric surface of the Lower Patapsco aquifer in the Patapsco Formation of Lower Cretaceous age in Southern Maryland during September 2002. The map is based on water-level measurements in 69 wells. The highest measured water level was 108 feet above sea level near the northwestern boundary and outcrop area of the aquifer in northern Anne Arundel County. From this area, the potentiometric surface declined towards large well fields at Severndale, Arnold, and Annapolis. The measured ground-water levels declined to 87 feet below sea level at Severndale, 39 feet below sea level at Arnold, and 43 feet below sea level a few miles west of Annapolis. There was also a cone of depression covering a large area in Charles County that includes Waldorf, LaPlata, Indian Head, and the Morgantown power plant. The ground-water levels measured were as low as 191 feet below sea level at Waldorf, 131 feet below sea level at LaPlata, 115 feet below sea level at Indian Head, and 86 feet below sea level at the Morgantown power plant.

Maryland↗
USGS2002

Potentiometric Surface of the Aquia Aquifer in Southern Maryland, September 2001

This report presents a map showing the potentiometric surface of the Aquia aquifer in the Aquia Formation of Paleocene age in Southern Maryland during September 2001. The map is based on water-level measurements in 76 wells. The potentiometric surface was highest at 40 feet above sea level near the northern boundary and outcrop area of the aquifer in the central part of Anne Arundel County, and was below sea level in the remainder of the study area. The hydraulic gradient was directed southeastward toward an extensive cone of depression around well fields at Lexington Park and Solomons Island. A cone of depression formed in northern Calvert County due to pumpage at Chesapeake Beach and North Beach. The water level has declined to 44 feet below sea level in this area. The lowest measurement was 160 feet below sea level at the center of a cone of depression at Lexington Park.

Open-File Report↗
USGS2002

The Difference Between the Potentiometric Surfaces of the Aquia Aquifer, September 1982 and September 2001 in Southern Maryland

This report presents a map showing the change in the potentiometric surface of the Aquia aquifer in the Aquia Formation of Paleocene age in Southern Maryland for September 1982 and September 2001. The map, based on water level measurements in 58 wells, shows that the potentiometric surface during the 19-year period declined from zero in the northernmost part of the study area, which is the outcrop of the aquifer, to 120 feet at Lexington Park. Lexington Park is near the southeasternmost part of the study area and approaches the downdip boundary of the aquifer.

Open-File Report↗