Ground-water hydraulics, regional flow, and ground-water development of the Floridan aquifer system in Florida and in parts of Georgia, South Carolina, and Alabama

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.

Arsenic and Antimony in Groundwater Flow Systems: A Comparative Study

“…From the Polk City region, groundwater flows radially outward toward the coast in the largely confined Upper Floridan aquifer, discharging in the case of our studied flow path, to the Gulf of Mexico in the vicinity of Venice, Florida ( Fig. 1; Bush and Johnston 1988;Wicks and Herman 1994;Sacks et al 1995;Plummer and Sprinkle 2001;Haque and Johannesson 2006b). Along the studied flow path, the Upper Floridan aquifer is confined from below by the middle confining unit (dolomite with intergranular anhydrite and gypsum) and from above by the overlying Hawthorn Group (sands, marl, clay, limestone, dolostone, and phosphatic depostits; Wilson and Gerhart 1979;Miller 1986;Lamoreaux 1989;Sacks et al 1995;Plummer and Sprinkle 2001).…”

Apparent CFC and 3H/3He age differences in water from Floridan Aquifer springs

“…The porosity and permeability of the UFA varies greatly near springs, because voids in the limestone range from small solution openings to large cavernous openings and networks of conduits. The transmissivity of the UFA near springs ranges from 2800 to 1.1!10 6 m 2 day K1 (Bush and Johnson, 1988) and reflects the large variation in permeability. Hunter's, Tarpon Hole and Deering Estate spring are considered submarine springs that discharge mainly fresh water directly into coastal salt marshes.…”

Using Multiple Chemical Indicators to Assess Sources of Nitrate and Age of Groundwater in a Karstic Spring Basin

“…Recharge to the unconfined UFA in this area ranges from 40 to 80 cm/year (15-31 in./year) (Grubbs, 1998) and is highly variable spatially and seasonally. Regional simulation of the groundwater flow system indicated that first-magnitude springs in this area receive only a very small amount of water from upward movement along deep regional flow paths originating in the lower part of the UFA (Bush and Johnston, 1988).…”