Estimated potentiometric surface for the Tertiary limestone aquifer system, southeastern United States, prior to development

Johnston, Richard H.; Krause, Richard E.; Meyer, Frederick W.; Ryder, Paul D.; Tibbals, C.H.; Hunn, James D.

doi:10.3133/ofr80406

Cited by 26 publications

(12 citation statements)

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“…Here, the overlying Hawthorn Group, which typically acts as a confining layer, is absent allowing for direct recharge to the Upper Floridan aquifer as evidenced by the predevelopment potentiometric high centered on Polk City (e.g., Stringfield 1936;Hanshaw et al 1965a, b;Johnston et al 1980). 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.…”

Section: Upper Floridan Aquifermentioning

confidence: 98%

Arsenic and Antimony in Groundwater Flow Systems: A Comparative Study

2011

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Arsenic (As) and antimony (Sb) concentrations and speciation were determined along flow paths in three groundwater flow systems, the Carrizo Sand aquifer in southeastern Texas, the Upper Floridan aquifer in south-central Florida, and the Aquia aquifer of coastal Maryland, and subsequently compared and contrasted. Previously reported hydrogeochemical parameters for all three aquifer were used to demonstrate how changes in oxidation-reduction conditions and solution chemistry along the flow paths in each of the aquifers affected the concentrations of As and Sb. Total Sb concentrations (Sb T ) of groundwaters from the Carrizo Sand aquifer range from 16 to 198 pmol kg -1 ; in the Upper Floridan aquifer, Sb T concentrations range from 8.1 to 1,462 pmol kg -1 ; and for the Aquia aquifer, Sb T concentrations range between 23 and 512 pmol kg -1 . In each aquifer, As and Sb (except for the Carrizo Sand aquifer) concentrations are highest in the regions where Fe(III) reduction predominates and lower where SO 4 reduction buffers redox conditions. Groundwater data and sequential analysis of the aquifer sediments indicate that reductive dissolution of Fe(III) oxides/oxyhydroxides and subsequent release of sorbed As and Sb are the principal mechanism by which these metalloids are mobilized. Increases in pH along the flow path in the Carrizo Sand and Aquia aquifer also likely promote desorption of As and Sb from mineral surfaces, whereas pyrite oxidation mobilizes As and Sb within oxic groundwaters from the recharge zone of the Upper Floridan aquifer. Both metalloids are subsequently removed from solution by readsorption and/or coprecipitation onto Fe(III) Electronic supplementary material The online version of this article (oxides/oxyhydroxides and mixed Fe(II)/Fe(III) oxides, clay minerals, and pyrite. Speciation modeling using measured and computed Eh values predicts that Sb(III) predominate in Carrizo Sand and Upper Floridan aquifer groundwaters, occurring as the Sb(OH) 3 0 species in solution. In oxic groundwaters from the recharge zones of these aquifers, the speciation model suggests that Sb(V) occurs as the negatively charged Sb(OH) 6 -species, whereas in sufidic groundwaters from both aquifers, the thioantimonite species, HSb 2 S 4 -and Sb 2 S 4 2-, are predicted to be important dissolved forms of Sb. The measured As and Sb speciation in the Aquia aquifer indicates that As(III) and Sb(III) predominate. Comparison of the speciation model results based on measured Eh values, and those computed with the Fe(II)/Fe(III), S(-II)/SO 4 , As(III)/As(V), and Sb(III)/Sb(V) couples, to the analytically determined As and Sb speciation suggests that the Fe(II)/Fe(III), S(-II)/SO 4 couples exert more control on the in situ redox condition of these groundwaters than either metalloid redox couple.

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Section: Upper Floridan Aquifermentioning

confidence: 98%

Arsenic and Antimony in Groundwater Flow Systems: A Comparative Study

2011

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“…In the unconfined section of the upper Floridan aquifer, groundwater flows radially outward from a potentiometric high in the center of Pasco County [Johnston et al, 1980] (Figure 1). Rainfall recharges the unconfined Floridan aquifer at a rate of about 30 cm/yr [Ryder, 1985].…”

Section: Field Site Descriptionmentioning

confidence: 99%

Regional Hydrogeochemistry of a Modern Coastal Mixing Zone

Wicks¹,

Herman²

1996

Water Resources Research

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In west central Florida, groundwater samples were collected along flow paths in the unconfined upper Floridan aquifer that cross the inland, freshwater recharge area and the coastal discharge area. A groundwater flow and solute transport model was used to evaluate groundwater flow and mixing of fresh and saline groundwater along a cross section of the unconfined upper Floridan aquifer. Results show that between 8% and 15% of the fresh and 30-31% of the saline groundwater penetrates to the depth in the flow system where contact with and dissolution of gypsum is likely. The deeply circulating fresh and saline groundwater returns to the near-surface environment discharging CaSO4-rich water to the coastal area where it mixes with fresh CaliCO 3 groundwater, resulting in a prediction of calcite precipitation in the modern mixing zone. saline groundwater environments [Stoessell et al., 1989•]. In Mallorca, Spain, mixing of fresh and saline water results in brackish water that is slightly oversaturated with respect to calcite but in equilibrium with respect to aragonite, abundant in the unsaturated zone through which local meteoric recharge to the aquifer occurs [Price and Herman, 1991]. However, previous studies have not had to account for the possibility of a 401 402 WICKS AND HERMAN: HYDROGEOCHEMISTRY OF A COASTAL MIXING ZONE

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“…Deep-well injection of wastes Goolsby (1972), Kaufman and others (1973), Wilson and others (1973), Kaufman and McKenzie (1975), Ehrlich and others (1979), Meyer (1980), Vecchioli (1981), Hickey (1982), and Merritt (1983).…”

Section: Trace Organic Contaminantsmentioning

confidence: 99%

Geochemistry of the Floridan aquifer system in Florida and in parts of Georgia, South Carolina, and Alabama

Sprinkle¹

1989

Professional Paper

150

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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.

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Estimated potentiometric surface for the Tertiary limestone aquifer system, southeastern United States, prior to development

Cited by 26 publications

References 0 publications

Arsenic and Antimony in Groundwater Flow Systems: A Comparative Study

Arsenic and Antimony in Groundwater Flow Systems: A Comparative Study

Regional Hydrogeochemistry of a Modern Coastal Mixing Zone

Geochemistry of the Floridan aquifer system in Florida and in parts of Georgia, South Carolina, and Alabama

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