bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Floridan Aquifer in Northeast Floridaa
Authors: Leve G. W. 
Published: July 2006

AbstractThe Floridan aquifer in northeast Florida is comprised of limestone and dolomite beds of Tertiary age. These formations in ascending order are: the Cedar Keys Formation of Paleocene age; the Oldsmar Limestone, Lake City Limestone, Avon Park Limestone, and the Ocala Group, all of Eocene age; locally the Suwannee Limestone of Oligocene age; and limestone and sand beds at the base of the Hawthorn Formation of Miocene age. The top of the Ocala Group ranges in elevation from 100 feet above sea level to 550 feet below sea level throughout the area.Except in the western part of the area where the Ocala Group is at the surface, impermeable beds in the Miocene to Recent deposits overlie the aquifer and confine the water under artesian pressure. Hard, impermeable beds within the aquifer separate the water‐bearing zones. The coefficient of transmissibility ranges from about 50,000 gpd/ft (gallons per day /foot) to more than 1,000,000 gpd/ft and the coefficient of storage ranges from 1.5 × 10−4 to 1.7 × 10−2 in areas where the water in the aquifer is under artesian conditions.The estimated annual recharge averages one‐half mgd (million gallons per day) in the western part of northeast Florida and 45 mgd in the south central part. Limited recharge also occurs throughout the central and eastern part of northeast Florida by downward leakage of water through the overlying confining beds. The coefficient of leakance of these confining beds ranges from about 1.7 × l0−2 to 1 ×10−3 gpd/ft3.Natural discharge occurs by perennial and intermittent springs and upward leakage through the confining beds in the areas of artesian flow. Artificial discharge by wells occurs principally in the farming, urban, and industrial areas in the eastern part of northeast Florida.Between 1940 and 1962 artesian pressures declined from 5 to 25 feet throughout the eastern part of northeast Florida.Seasonal declines of artesian pressure of 5 to 10 feet in the farming areas resulted in temporary increases of chloride content of water of 200 to 500 ppm (parts per million). The chloride content of water in the aquifer in the vicinity of Jacksonville and Fernandina has increased from 22 to 1400 ppm in wells more than 1,400 feet deep. Thus far, impermeable zones below the fresh water have prevented serious salt‐water contamination in shallower wells at Jacksonville and Fernandiua.
Monitoring of Changes in Quality of Ground Watera
Authors: LeGrand Harry E. 
Published: July 2006

AbstractGround water of acceptable quality is commonly interspersed with water of inferior quality. Water of inferior quality may be naturally occurring salty water commonly underlying fresh water, or it may be enclaves of contaminated water from wastes that lie in the fresh‐water bodies. Disposal of wastes on and in the ground and pumping of water from wells cause a dispersion of contaminated water; migration of contaminated water toward wells may be spontaneously induced by the natural hydraulic gradient, or it may be induced artificially by the cone of depression about one or more wells. Economic methods of determining precisely the boundary zones between contaminated and uncontaminated water are not available. Much reliance is placed on monitoring wells.A prerequisite to monitoring is a synthetic hydrogeologic framework or model in which the behavior of the contaminated water is conceived. Such a conceptual model, using pertinent data that are available, helps to assess the need for monitoring and to guide a monitoring program for optimum results. Unplanned, indiscriminate monitoring of water from wells is expensive, inefficient, and fallible. The need for monitoring will increase in the future; yet, the proper objective is to improve the technology of determining the distribution of contaminated water so that monitoring can be minimized and conducted with optimum results.
Geophysical Logging and Hydraulic Testing, Pahute Mesa, Nevada Test Sitea
Authors: Blankennagel Richard K. 
Published: July 2006

AbstractThe U. S. Geological Survey, on behalf of the U. S. Atomic Energy Commission, performs a broad range of geologic and hydrologic studies related to underground nuclear explosions at the Nevada Test Site. One phase of the studies involved extensive geophysical logging and hydraulic testing in deep exploratory holes at Pahute Mesa, Nevada Test Site. Various geophysical logs and hydraulic testing techniques used in the study are described in this paper.Interpretations of logs and logging techniques depend on factors such as rock characteristics in a particular area, drilling methods, and the objectives of the hydrologic investigations. From experience gained at Pahute Mesa, some qualitative data on rock lithologies and hydraulic conditions in the borehole may be determined by electric, caliper, temperature, and fluid resistivity logs. Quantitative data on the major water‐yielding intervals in the borehole are obtained from radioactive tracer or spinner surveys. Interpretations of the geophysical logs have been verified by isolating specific zones in the drill holes with inflatable packers and spacers. These intervals were tested by injection or swabbing of fluid and measuring the resultant change in water level caused by fluid outflow from or inflow to the interval of rock isolated by the packers.
Volume of Aquifer Tested for Permeability During a One‐Well Pumping Test
Authors: Strausberg Sanford I. 
Published: July 2006

AbstractPumping test data from a single well were used to estimate aquifer volume affecting drawdown. After four days of pumping from a 240 feet thick welded tuff aquifer in southern Nevada, the volume of the wedge‐shaped mass tested was estimated to be about 15.6 billion cubic feet (440 million cubic meters). The field coefficient of permeability of the aquifer is 275 gallons per day per square foot.
Cones of Influence Developed in the Silurian‐Devonian Aquifer, Maumee River Basin, Ohio
Authors: Rowland Mark R. , Kunkle George R. 
Published: July 2006

AbstractIn the Maumee River Basin of northwestern Ohio the principal source of ground water is the Silurian‐Devonian carbonate aquifer. The use rate of ground water from this aquifer could rapidly increase many fold in the near future. This situation demands quantitative information on the resource potential of the aquifer, if proper development is to be encouraged.A relationship between ground‐water use and recharge rates through an analysis of the cones of influence is demonstrated in this paper. Computed recharge rates for the cones of influence vary from 6,800 to 75,300 gpd/sq mi, and the variation is systematic in that the higher recharge rates correlate with the higher pumpage rates. Recharge rates appear to have an upper limit of approximately 100,000 gpd/ sq mi, which corresponds to a maximization of the vertical hydraulic gradient. Although maximization of the vertical hydraulic gradient is impossible to achieve for a given cone of influence, it can be approached by lowering the piezometric surface of the aquifer by increasing the pumpage rate.Assuming that the safe yield of an aquifer is equivalent to the rate of recharge, this study demonstrates that development of an aquifer can increase many times its potential.
Electric Well Logging of Hawaiian Basaltic Aquifers
Authors: Peterson Frank L. , Lao Chester 
Published: July 2006

ABSTRACTAn extensive program of electric well logging has been conducted in Hawaii during the past three years to determine the applicability of this tool to the volcanic environment which exists in Hawaii. Electric well logging techniques were found to be useful in Hawaiian basaltic aquifers; however interpretation of both spontaneous potential logs and resistivity logs varies from the conventional interpretation of electric logs in sediments. The interpretation of fluid conductivity logs in Hawaii follows conventional water well techniques.The analysis of spontaneous potential and resistivity well logging in basalts, which constitute most of the Hawaiian aquifers, poses problems because of the relatively uniform composition of the basalts and the complex relation of porosity to resistivity in basaltic aquifers, and because logging usually is performed in water‐filled boreholes. Spontaneous potentials are thought to result primarily from fluid flow rather than from electrochemical potential, and positive SPs generally indicate zones with flow from the aquifers into the well, and negative SPs generally indicate zones with little flow or flow from the well into the aquifer. Resistivity logs indicate the location, number, individual thickness, and total thicknesses of permeable and less permeable formations, and are useful as indicators of water‐yielding zones. High resistivities generally are indicative of dense impermeable basalts and low resistivities are indicative of porous permeable zones most likely to contribute water to the borehole. Both resistivity and spontaneous potential logs provide a direct measurement of depth to water, depth of casing, and depth of hole.
Type‐Curve Solution of Step‐Drawdown Test
Authors: Sheahan N. Thomas 
Published: July 2006

AbstractA set of type‐curves is presented which simplifies and quickens the solution of the Rorabaugh equation for drawdown in a pumping well by eliminating the trial‐and‐error computations. Type‐curve analysis of test data in the field, before pumping is discontinued, provides an indication of the accuracy and adequacy of test data points. For optimum accuracy, test data should cover the portion of maximum curvature of the curve, and the range between the lowest and the highest pumping rates used in the step‐drawdown test should be great enough to define a unique curve.
Recharge Characteristics of a Watercourse Aquifer System at Springfield, Ohioa
Authors: Norris Stanley E. , Eagon Herbert B. 
Published: July 2006

ABSTRACTAn investigation was made of infiltration conditions in the alluvial‐filled Mad River valley in the vicinity of the Springfield municipal wells. The study shows that most recharge to the 100‐foot thick sand and gravel aquifer is from induced infiltration from the Mad River. Local precipitation and natural, down‐valley underflow also are important in sustaining the 14 mgd (million gallons per day) pumping rate.The investigation was designed to learn more about rates of streambed infiltration. Gaging stations were established at points above and below the well field in the expectation that infiltration losses could be measured directly. The attempt was unsuccessful because infiltration losses proved too small to measure accurately by ordinary stream gaging methods. The investigation has, nevertheless, provided much new data about this important watercourse aquifer system.Observation‐well records covering the 4‐year period 1965 through 1968 show that ground‐water levels follow an annual cycle, typically rising in the period February through June, when recharge exceeds depletion, and falling during the remainder of the year. The rate of induced stream infiltration is not sufficient to prevent perennial dewatering of the aquifer beneath the streambed. The water table beneath the center of the losing reach ranges in depth from about 17 feet in January to about 6 feet in June in the average year. Bedrock highs beneath the stream, which result in local thinning of the aquifer upstream and downstream from the well field, essentially limit infiltration to a reach about 2½ miles long having an area of approximately 24 acres. During the 7‐month depletion period average infiltration is estimated at 9 mgd and during the 5‐month accretion period estimated infiltration is 12 mgd. On the basis of these estimates the infiltration rate for the respective periods is 0.37 and 0.50 mgd per acre, or about 0.35 mgd per acre per foot of depth.
Observations on Water Content Changes in Stratified Sediments During Pit Rechargea, b
Authors: Wilson L. G. 
Published: July 2006

ABSTRACTTwo pit recharge tests were conducted at an instrumented research site near Tucson, Arizona using cooling tower blowdown effluent from a nearby power plant. The first trial in 1966 consisted of 142 days of continuous inundation. The second test in 1968, comprised 15 wet‐dry cycles with a total inundation time of 80 days. Quantities recharged by the two management techniques were contrasted. Water content profiles, obtained via a “moisture logger” in 14 access wells, clearly delineated two principal zones of water transmission on mounds within stratified materials of the 80 ft zone of aeration at the site. During the continuous inundation test three stages were apparent in the history of these mounds: growth stage, equilibrium stage and drainage stage. It was possible to relate these various stages to intake characteristics of the pit. The development of models to characterize recharge within the zone of aeration in areas of the Tucson basin with geological controls similar to those at the recharge site, should accommodate the three stages in the history of mound development and dissipation.
Replenishment Sources of the Alluvial Aquifers of the Peruvian Coast
Authors: Gilboa Yaakov 
Published: July 2006

ABSTRACTGround water in the arid coastal area of Peru occurs in more than fifty alluvial aquifers. The aquifers are limited to river valleys and to nearby sedimentary plains.The coast is rainless and the river valleys serve as the drainage outlet of the western slopes of the Andes. The coastal alluvial aquifers are located below the lower limit of the active catchment areas, and are not recharged directly by precipitation.The long igneous batholith and the volcanic formations of the Andean Cordillera form an impermeable barrier which prevents the replenishment of the aquifers by underflow from the Andes.The main source of replenishment of the aquifers in the Peruvian coastal zone is river water. The water infiltrates through the river beds and irrigation canals and migrates laterally within the alluvial deposits. Another important source of recharge is return flow from irrigation. Water also enters the aquifers through boundary faults.
Factors Affecting the Validity of Chemical Analyses of Natural Water
Authors: Summers W. K. 
Published: July 2006

ABSTRACTChemical analyses of natural water may be inadequate because of inadvertent human errors and sample aging. Characteristic deficiencies can be demonstrated by multiple chemical analyses of the same sample by different laboratories, multiple analyses of the same sample by one laboratory, repeated analyses of one sample as a function of time, and a simple laboratory experiment in rock‐water chemistry. Whenever possible, complete chemical analyses should be made. The most reliable analyses are those in which combining weights of the cation equal the combining weight of the anion and in which the sum of the individually measured constituents equals the observed residue on evaporation at 180°C (total dissolved solids).
Application of Nonparametric Statistical Tests in Hydrogeology
Authors: Siddiqui S. H. , Parizek R. R. 
Published: July 2006

ABSTRACTAppropriate nonparametric or distribution free statistical techniques are useful tools when data do not satisfy the conditions required by parametric statistical tests, and may be applied to a variety of hydrogeological problems. Two nonparametric tests, Krusk‐Wallis One‐Way Analysis of Variance and Mann‐Whitney U Test, were used to test the significance of observed differences in well yields with respect to variation in controlling hydrogeologic factors. This paper presents the steps involved in performing these two tests with one example for each and suggests other applications to water‐related problems. To avoid computational errors and save time, a computer program was written for calculating the statistics used in these tests.
Infill of Nuclear Rubble Chimneys by Ground Watera
Authors: Fenske Paul R. , Charnell Robert L. 
Published: July 2006

ABSTRACTThis paper presents some of the preliminary results of a theoretical analysis of the ground‐water infill rate of a rubble chimney produced by an underground nuclear explosion. The study was conducted to evaluate effects that various features of the hydrogeology regime have on rate of infill. This model for infill is based on the analogy of a rubble chimney to a small diameter gravity well. The infill history is approximated by integrating production from a series of steady state infill rates based on Dupuit‐Forchheimer assumptions. The model has been used for parameter sensitivity analysis. Of the aquifer characteristics, changes of the hydraulic conductivity have the greatest effect on infill; the radius of influence is most sensitive to changes in the specific yield. The effect of infill rate of using a rubble porosity that decreases with depth is small, although initial infill is more rapid. The hydrogeology data from two events where infill data are available have been used with this model for verification. For both BILBY and GREELEY events, agreement between measured and calculated infill data are good. BILBY data suggest that substantial dewatering of the rubble in the chimney occurred before much ground water entered the chimney. Comparison of the GREELEY data indicates that dewatering of the rubble is minimal but that porosity of the rubble near the surface was higher than originally anticipated.
Ground‐Water Volumes from Anomalous Mass Determinations for Alluvial Basinsa
Authors: West Robert E. , Sumner John S. 
Published: July 2006

ABSTRACTIf there are gravity data and some geological information available from the region of an intermontane basin, then the volume of saturated sediments, volume of ground water available from storage, and the total volume of ground water can be determined from the gravitationally determined anomalous mass. The anomalous mass occurs because of a density contrast which exists between low density alluvium and high density bedrock which define the surface and subsurface boundaries of the basin. The gravity effect of the anomalous mass can be detected by a gravity survey of the basin after which it can be separated from other gravity effects by a regional‐residual separation. The anomalous mass is uniquely determined by applying Gauss's theorem to the residual gravity map.A model of an intermontane basin is developed which relates the anomalous mass to the total volume of saturated sediments. The total volume of saturated sediments is determined from the anomalous mass, the density contrasts between unsaturated and saturated alluvium and bedrock, the area of the basin, and the water table depth.The volume of water available from storage and the total volume of water in the basin are determined from the volume of saturated sediments and the storage coefficient and porosity of the sediments.The method is illustrated by a case history from Avra Valley, Arizona. It is concluded that the major advantage of this method occurs when well data are not available, because it eliminates the need for arbitrary assumptions about subsurface basin geometry to determine the volume of saturated sediments.
The Genesis of Selected Hydrochemical Facies in Baton Rouge, Louisiana, Ground Waters
Authors: Khan Rashid A. , Ferrell Ray E. , Billings Gale K. 
Published: July 2006

ABSTRACTBicarbonate‐rich ground waters are present beneath Baton Rouge, Louisiana. They may be subdivided into two subtypes based on the dominant cation. Many ground waters are Na‐rich, the others are Ca and Mg‐dominant bicarbonate waters. Na/Ca and Na/Mg epm ratios in the Na‐rich subfacies are 126‐394 and 347‐1649, respectively. The corresponding ratios in the Ca + Mg‐dominant subfacies are 0.14‐0.58 and 0.17‐0.58. The HCO3 concentration varies from 77 to, 412 ppm and the total dissolved solids content is usually lower than 500 ppm.The chloride ion is dominant in some chemical analyses of Baton Rouge ground waters. These waters form a separate hydrochemical facies whose origin is not discussed in this report.Multiple regression analyses of the ion distributions and calculated correlation coefficients for ion associations help quantify the distribution of the dissolved species and help to define the proposed mechanisms for genesis of the ground waters. Ion exchange, selective filtration of dissolved constituents, and mixing of surface waters in the aquifers are the primary mechanisms controlling the chemical composition of the ground waters. The occurrence of the Na‐HCO3 facies at shallow levels in the area of maximum offtake is especially interesting. This is attributed to the accelerated ion filtration accompanying the high rate of ground‐water production.
An Approach to Hydrogeologic Investigations of River Alluvium by the Use of Computerized Data Processing Techniquesa
Authors: Kent Douglas C. , Naney James W. , Barnes Bill B. 
Published: July 2006

ABSTRACTA data storage and retrieval system for hydrogeologic data is designed to produce lithology distribution maps, isopachous maps, and cross sections showing the boundaries and hydraulic characteristics of river alluvium. Emphasis has been placed on selecting and coding characteristics of the alluvial sediments which will facilitate description in terms of hydraulic properties and in a manner convenient for interpretation. The hydraulic properties of fluvial deposits for input to the system are defined based on analysis of core samples and pump tests.A ground‐water study, for which this retrieval system was designed, is part of the research being conducted by the Agricultural Research Service in the Washita River valley in south‐central Oklahoma near Chickasha. In the ground‐water study, maps and cross sections from the retrieval system are used—in conjunction with the hydraulic coefficients and water‐level records—to estimate the rate of ground‐water flow and storage for selected time increments. This information is needed in the study for developing a mathematical model of surface runoff as influenced by upstream tributary development.
Investigation of a Landfill in Granite‐Loess Terrane
Authors: Seitz Harold R. , Wallace Alfred T. , Williams Roy E. 
Published: July 2006

ABSTRACTThe hydrogeologic environment adjacent to the sanitary landfill used by the City of Moscow, Idaho, was investigated in an attempt to identify the factors contributing to its alteration and to the reported alteration of ground water downgradient from the fill. The refuse disposal trenches cut through loess and penetrate weathered granite. Field observations and samples from piezometer drillholes showed the major aquifer in the area to be the weathered granite underlying the loess, particularly in the draws. Ground‐water samples collected from the piezometers and from a stream downgradient from the landfill revealed that certain aspects of surface water quality are degraded and that shallow ground water is slightly contaminated. However, serious widespread pollution of ground water by the landfill is not in evidence.Electrical resistivity was tested as a means of detecting leachate from landfills in this type of environment. Comparison of resistivity data with water quality data showed that the technique is satisfactory, provided traverses are nearly horizontal.