Hydrogeologic framework of the northern Atlantic Coastal Plain in parts of North Carolina, Virginia, Maryland, Delaware, New Jersey, and New York

Abstract

The Regional Aquifer-System Analysis (RASA) Program was started in 1978 following a congressional mandate to develop quantitative appraisals of the major groundwater systems of the United States. The RASA Program represents a systematic effort to study a number of the Nation's most important aquifer systems, which in aggregate underlie much of the country and which represent an important component of the Nation's total water supply. In general, the boundaries of these studies are identified by the hydrologic extent of each system and accordingly transcend the political subdivisions to which investigations have often arbitrarily been limited in the past. The broad objective for each study is to assemble geologic, hydrologic, and geochemical information, to analyze and develop an understanding of the system, and to develop predictive capabilities that will contribute to the effective management of the system. The use of computer simulation is an important element of the RASA studies, both to develop an understanding of the natural, undisturbed hydrologic system and the changes brought about in it by human activities, and to provide a means of predicting the regional effects of future pumping or other stresses. The final interpretive results of the RASA Program are presented in a series of U.S. Geological Survey Professional Papers that describe the geology, hydrology, and geochemistry of each regional aquifer system. Each study within the RASA Program is assigned a single Professional Paper number, and where the volume of interpretive material warrants, separate topical chapters that consider the principal elements of the investigation may be published. The series of RASA interpretive reports begins with Professional Paper 1400 and thereafter will continue in numerical sequence as the interpretive products of subsequent studies become available.

Groundwater level response in U.S. principal aquifers to ENSO, NAO, PDO, and AMO

“…This study focused on wells in the surficial aquifer that consists of unconsolidated sand and gravel and is the uppermost aquifer in the North Atlantic Coastal Plain aquifer system (Trapp, 1992). Average annual temperature is 11° C and average annual precipitation is 1,044 mm (Polsky et al, 2000).…”

Selected hydrogeologic and chloride-concentration data for the northern and central coastal area of New Castle County, Delaware

“…(1) Results of studies of the general geology and hydrology of the study area have been reported by Jordan and Groot (1962), Bonini (1967), Spoljaric (1967), Spoljaric and Woodruff (1970), Owens and others (1970), Pickett (1970), Pickett and Spoljaric (1971), Gushing and others (1973), Woodruff (1981 and1986), Duran (1986), Trapp (1992), and Vroblesky and Fleck (1991).…”

A direct immunoassay for detecting diatoms in groundwater as an indicator of the direct influence of surface water

“…The uGW was collected from a public supply well in the Piney Point Aquifer in Southeastern New Jersey. This confined aquifer extends from Virginia through New Jersey, is approximately 2/3 the width of the North Atlantic Coastal Plain, and does not outcrop in either Maryland or New Jersey (Trapp, 1992). Carbon-14 age estimates for samples taken from this aquifer in Maryland are greater than 30,000 yr old (Aeschbach-Hertig et al, 2002).…”