bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ground Water, Gravity and Rift Valleys in Malawi
Authors: Davis Richard W. 
Published: July 2006

AbstractA preliminary geohydrologic survey was carried out in the Lower Shire Vailey, Malawi, Africa in the summer of 1967. The valley is part of: he East African Rift System. In order to develop more adequate knowledge of subsurface conditions, a reconnaissance gravity survey was performed. The survey showed that potential aquifer material over much of the valley was too chin to support high yield irrigation wells. In addition, when combined with hydrochemical data the survey disclosed a high probability of water contamination by brines circulating upward along fault systems.
Control of Sea‐Water Intrusion in a Ground‐Water Aquifera
Authors: Bruington A. E. 
Published: July 2006

AbstractSea‐water intrusion into ground‐water reservoirs occurs when permeable formations outcrop into a body of sea water and when there is a landward gradient. Intrusion can be controlled by reducing pumping, by increasing supply, or by forming some type of barrier. A pressure barrier has been operated in Los Angeles County, California. Special facilities are needed. Costs of operation are high.The intrusion of sea water into ground‐water reservoirs can greatly impair the water‐supply systems of local areas adjacent to coastlines and tidal estuaries. Such intrusion is always the result of some activity of man either in trying to improve his environment or in his use of natural resources. Following is a discussion of how intrusion occurs, some ways of controlling intrusion, the results of one project in southern California where intrusion is being controlled, and some examples of related costs.
Significance of Ground‐Wafer Management Strategy— A Systems Approacha
Authors: Beaver J. A. , Frankel M. L. 
Published: July 2006

AbstractIn Southern California's San Bernardino Valley a unique experiment is being performed by a local water district, the State government, and a private industry. Both the experiment and the organizational arrangements for getting the job done are the subject of this paper. The experiment is the application of systems analysis technology to water resource management. The organization is formed by a combination of contracts and cooperative agreement between private and government agencies. The result is a favorable environment for the development of effective water resource management strategies.The San Bernardino Valley is similar Co many areas in the world where water resource management reduces to the allocation of locally available ground water and potential imported water resources. This paper outlines in detail the analysis tools and long‐range planning needs of effective ground‐water management strategies.
Methods for Calculating the Cost of Developing Ground‐Water Resources in Appalachiaa
Authors: Wyrick Granville G. 
Published: July 2006

AbstractThe project developed between the U. S. Army Corps of Engineers, Office of Appalachian studies and the U. S. Geological Survey for a study of the ground‐water resources in Appalachia had two principal objectives. The first objective was to describe in general terms the ground‐water resources of the Region as a whole and the second objective was to describe in greater detail the ground‐water resources at about 20 selected sites. This paper deals with the methods used to describe the Region as a whole, wich a special emphasis on availability and cost of developing ground water, as was requested by the Office of Appalachian Studies.
Air Pump for Small‐Diameter Piezometers
Authors: Trescott Peter C. , Pinder George F. 
Published: July 2006

AbstractThe engine of a field vehicle can easily be used as an air pump by inserting a commercially manufactured check valve into a spark‐plug socket. Small‐diameter piezometers can be pumped with compressed air from this source. With sufficient air‐line submergence, the air lift method can be used to pump 1‐inch diameter piezometers where the pumping lift is less than 70 feet and 1.25‐inch diameter piezometers where the pumping lift is less than 50 feet. In cases where this method will not work, some of the water contained in a piezometer can be pumped out by pressurizing the piezometer if the formation transmissivity is low and the pumping lift is not excessive. The maximum pumping lift is a function of the rate at which pressure in the piezometer is increased and the rate at which water flows into the formation with increasing head in the piezometer.The engine air pump is useful in developing piezometers, flushing out stagnant water before taking water samples, obtaining water samples, and creating head differences to initiate slug tests.
Drain Installation for Nitrate Reductiona
Authors: Willardson L. S. , Meek B. D. , Grass L. B. , Dickey G. L. , Bailey J. W. 
Published: July 2006

AbstractA field experiment has been installed near Firebaugh in the San Joaquin Valley of California to test submergence of drains as a means of denitrification of ground water. Laboratory and field experiments have shown that denitrification occurs in saturated soil where there is ample organic carbon available for bacterial metabolism. Denitrification and dilution of high nitrate ground water were accomplished in the field.
Aquifer Simulation on Slow Time Resistance‐Capacitance Networks
Authors: Rushton K. R. , Bannister R. G. 
Published: July 2006

ABSTRACTFor several years resistance‐capacitance networks have been used to simulate aquifers. Most reported work has been concerned with fast time analogues in which the period under consideracign is represented in micro‐seconds. However the alternative slow time analogue has many advan tages since the electrical experiment takes several seconds. This results in simpler equipment and simpler experimental techniques.The paper concentrates on the practical aspects or the slow time analogue giving details of the components, describing a method of simulating wells and recharge and comparing measuring instruments. The techniques are illustrated by a simplified example.
A Computer Method for Pumping‐Test Analysis
Authors: Saleem Z. A. 
Published: July 2006

AbstractThe knowledge of aquifer parameters is invaluable for quantitative description of geohydrologic systems and for optimal utilization of ground‐water resources. The classical methods of pumping‐test analysis are mostly graphical in nature and there is room for error in individual judgment in the geographical analysis. The computer method for aquifer evaluation comes under the inverse analysis techniques and is based on the classical principle of least squares. The sum of the weighted squares of differences between the observed drawdowns and the drawdowns calculated using the theoretical drawdown equations for the flow system under consideration is minimized, treating the aquifer parameters as decision variables. The method can be applied to any flow system for which analytical expressions for the potential distribution are known. The method was successfully applied to four pumping tests, two in nonleaky confined flow 1 systems, one in a leaky confined flow system, and one in an anisotropic nonleaky confined flow system. The percentage differences between the values of storativity and of transmissivity arrived at by the two methods are found to be as much as 24‐and 1.6 percents, respectively.
Use of Alluvial Faults in the storage and Retention of Ground Watera
Authors: Williams Dennis E. 
Published: July 2006

AbstractAlluvial faults are generally treated as impermeable boundaries. Recent investigations of the faults in Califoria's Owens Valley, however, reveal that they are semi‐pervious, or leaky in nature. The rate of ground‐water movement through a semi‐pervious alluvial fault is dependent upon the hydraulic conductivity of the fault gouge, the thickness of this zone, and the water‐level differential across the fault. Optimization of the ground‐water resources in the Owens Valley is currently being practiced using these faults in a controlled RECHARGE‐EXTRACTION‐SALVAGE System. In a system of this type, artificial recharge is induced into the Valley's aquifers upgradient from alluvial fault zones by impounding and diverting the creek flow tributary to the area. Extraction of ground water is effected by means of large‐diameter supply wells located near the faults on the upstream side. Salvage of ground water is accomplished by lowering the water table in the vicinity of these faults, thereby causing phreatic growth to die out. When predicting water levels in the vicinity of semi‐pervious faults, a solution is obtained for the induced water‐level decline caused by backward leakage through the faults.
ModelTests for a Horizontal Well
Authors: Peter Yehuda 
Published: July 2006

AbstractThis paper deals with the ground‐water flow into a drilled well, consisting of a vertical shaft and radially spaced horizontal intake pipes.It is based on model tests, devised and executed by the author in the Hydraulic Laboratory of the Haile Selassie I University in Addis Ababa, Ethiopia.The author tested the assumption of linearly distributed inflow into the pipes, based on the steady‐flow theory of Darcy‐Thiem, and found satisfactory agreement between theory and experiment.
The Rock and Bong Techniques of Measuring Water Levels in Wells
Authors: Stewart David M. 
Published: July 2006

AbstractMeasurement of the depth to water in wells can be accomplished by timing the fall of a marble or BB. Depth to water can also be determined in terms of the frequency of the reverberations heard in a well. These two methods are called the rock and the bong techniques respectively. Their theoretical basis, their proper execution, and their usefulness are discussed.
Water Levels in Carbonate Rock Terranesa
Authors: LeGrand Harry E. , Stringfield V. T. 
Published: July 2006

AbstractMany subtle aspects of water levels in carbonate rocks need to be put in perspective even though hydrologists have recognized the fundamental value of characteristics of ground‐water levels. The depth to the water table in carbonate rocks is controlled by local factors such as permeability and topography and by the regional factor of climate; both permeability and topography are dynamically developed according to the degree of preferential circulation of subsurface water and of solution of the rock, and the water table responds by lying deep beneath hilly permeable karstlands and shallow beneath flat and poorly permeable carbonate rocks. The uneven distribution of permeability and of topographic conditions is responsible for the intriguing karst phenomena of disappearing and reappearing surface streams. Great infiltration capacities of some karst regions result in large local fluctuations of the water table and in some cases to local reversals in direction of ground‐water flow between wet and dry seasons. Water‐level behavior in space and time is a primary consideration for interpreting the hydrology of carbonate terranes.
Where Does Water Quality Improvement Begin?
Authors: Jones Elmer E. 
Published: July 2006

AbstractMost ground‐water aquifers have a multibarrier natural defense system. With all these natural defenses, why are there so many contaminated wells? In most cases the well itself is the path of entrance for the contamination. The American Water Works Association and the National Water Well Association state in their joint Standard for Deep Wells: “Only when the sole available water‐bearing formation lies so near the surface that it is continually contaminated is production of a safe supply not feasible.” Only in very rare circumstances is it economically justified to substitute disinfection for adequate protection of a ground‐water source.Rapid changes in well water quality with pumping time indicate less than optimum construction. Poorly constructed and abandoned wells serve as unauthorized and uncontrolled ground‐water recharge points and have a degrading effect on ground‐water quality. Water quality improvement should begin with excluding water of undesirable quality from the source of supply. For the home owner and farmer to profit from this ideal it must be accepted by well drillers, water conditioning dealers, and county and State health departments.
Hydrogeology in Czechoslovakiaa
Authors: Zaporozec Alexander 
Published: July 2006

ABSTRACTGround water is an important source of water supply in Czechoslovakia, and its use is very carefully planned because the resources are unevenly distributed. The supply is limited because Czechoslovakia is situated on the European water divide between the North, Baltic, and Black Seas, and all waters flow out of the State. The paucity of ground‐water resources, requiring assessment and classification of the utilizable ground water, has led to development of a State ground‐water resources zoning plan. Increasing demand for ground water has resulted in extensive and responsible hydrogeological research, contributing to a good knowledge of the ground‐water resources. Czechoslovak hydrogeology has been developed to a high level, even though it is a relatively young branch of science, and stands in some respects in the forefront of world hydrogeology, especially in prospecting, development and protection of mineral‐water resources, hydrogeological mapping, and ground‐water zoning.
Protective Pumping to Reduce Aquifer Pollution, Glynn County, Georgiaa
Authors: Gregg Dean O. 
Published: July 2006

AbstractWater‐level declines in the principal artesian aquifer have created a head imbalance between the aquifer and an underlying brackish‐water zone containing up to 4,550 mg/1 chloride. The brackish‐water zone leaks brackish water into the aquifer through several breaks in a confining unit.A relief well tapping the brackish‐water zone was drilled near a suspected break and pumped at about 3,000 gpm to lower the potential in the zone and bring it into hydrostatic equilibrium with the aquifer. The pumping apparently succeeded in decreasing the rate of brackish‐water leakage into the aquifer. Successive samples of water from a well tapping the aquifer and downgradient from the relief well showed a decrease in the chloride content. Several more relief wells may be necessary to ultimately control chloride contamination of the aquifer.
Survey of Interstate and International Aquifer Problems
Authors: Bittinger Morton W. 
Published: July 2006

ABSTRACTA survey of State water agency and university personnel was conducted to identify and classify interstate and international aquifer problems in the conterminous United States. Questionnaires returned identified nearly 200 of such situations. Of these, 30 situations were classified as being a major problem at the present time. An additional 73 situations were classified as minor at the present time. For those problems that were indicated as being expected to develop within the next five years, 9 were classified as major and 25 as minor. For those problems that were indicated as being expected to develop after five or more years, 19 were classified as major and 42 as minor.
The Role of the U. S. Geological Survey in Waste Disposal Monitoringa
Authors: Callahan Joseph T. 
Published: July 2006

ABSTRACTThe disposal of all types of liquid and solid wastes threatens the health and well‐being of mankind. In recent years the constraints on the disposal of industrial and municipal wastes into rivers and the seas have prompted the disposal through wells into the subsurface. Limestone terrane is particularly amenable to the acceptance of all types of wastes in the cavernous subsurface, and has resulted in widespread contamination of shallow ground‐water resources. Highway salting has caused the contamination of thousands of household wells, causing large‐scale replacement drilling programs in some northern States. A semantics problem also has arisen, because liquid wastes injected into the subsurface have not been disposed of, but rather have been placed in a new environment. They may be in storage, they may be attenuating, or they may be changing character by reaction with the rock mass or formation fluids.The U. S. Geological Survey has been concerned with the study of ground‐water resources for more than 80 years, and with the problems of radioactive waste contamination since World War II. A newly identified program of investigations of waste emplacement into the subsurface was begun two years ago. The purpose of the program is to develop the ability to predict the fate of any wastes deliberately or accidentally emplaced in the subsurface. The program includes research contracts and grants with universities and governmental organizations as well as in‐house research.
A Basin Study of Ground‐Water Discharge from Bedrock into Glacial Drift Part I—Definition of Ground‐Water System
Authors: Kent Douglas C. , Sendlein Lyle V. A. 
Published: July 2006

ABSTRACTA regional preliminary ground‐water investigation was conducted in the Upper Skunk River Basin near Ames, Iowa. A systematic basin approach integrating geological, geophysical, ground‐water, and water quality investigations was used to study this 800‐square mile basin. The data were compiled in such a manner that first, second and final approximation maps could be constructed. Interpretation of first approximation maps led to a field program which resulted in the second approximation maps. Examination and comparison of the second approximation maps through a system of acetate overlays pointed to problem areas which with further geophysical and geological field checks led to construction of the final approximation maps.A complex system of bedrock channels were defined using electrical resistivity, shallow seismic refraction and geological methods. A series of map overlays define the bedrock topography, the subcrop geology, the piezometric surface, the sand and gravel thickness, the distribution of water quality, resistivity data and regolith lithology.Hydraulic continuity between a partially‐confined bedrock aquifer and channel and shallow sands is indicated from a comparison of piezometric and water quality maps. The similarity of bedrock and piezometric surfaces is evidence of discharge from the bedrock into the channel sands and gravel. Finally, a bedrock recharge map was prepared in order to define zones of ground‐water recharge from the bedrock.
Well Losses Due to Reduced Formation Permeability
Authors: Karanjac Jasminko 
Published: July 2006

ABSTRACTSteady‐state flow to a single well fully penetrating a confined isotropic aquifer is analyzed. The hydraulic conductivity of the aquifer changes exponentially from a minimum value at the well face to a constant value in the “undamaged” aquifer. An‐equation for laminar flow well losses that are due to a decreased permeability in the vicinity of the well is obtained. The well loss depends upon the pattern in which permeability changes. The integral expressing the well loss is evaluated numerically. The results are presented in a graph with nondimensional parameters and could be used for engineering evaluation of the laminar well loss.
The Use of Gamma Logs in Determining the Character of Unconsolidated Sediments and Well Construction Featuresa
Authors: Norris Stanley E. 
Published: July 2006

ABSTRACTGamma logs, by revealing differences in the radiation intensity of unconsolidated sediments, can provide important information on the depth and sequence of beds penetrated by a cased well. In some instances the log of a well drilled into a sand and gravel aquifer can indicate the interval, or intervals, most favorable for screening. Changes in logs made before and after a well is screened and developed can show zones in the screened interval where most development occurred, and provide valuable clues as to the overall effectiveness of development.Although little used at present, gamma logging holds promise of becoming an important tool in hydrologic studies and in the well construction industry. More testing and possibly standardization of equipment is currently needed, along with experimentation in logging techniques, to improve the method. Field correlation between logs and drilling samples are necessary to improve the accuracy of log interpretation.
Ground Water and Land Values in Southwestern Kansasa
Authors: Lee Samuel H. , Bagley Edgar S. 
Published: July 2006

ABSTRACTGround‐water irrigation has developed rapidly in the High Plains region of the United States, especially in Texas since the 1930's and more recently in western Kansas. Although most land sales transactions do not show the water value separate from the dry land value, the availability of ground water has greatly affected land values. This study measures this effect by two methods for an area of southwestern Kansas where ground‐water irrigation has become important.The purchasers of all farm land sold in the selected area between 1962‐67 were surveyed to obtain information on sale price and numerous factors which it was thought might have a bearing on the land value. One method of measuring the effect of ground water on land value involved matching a number of tracts not known to have available ground water for irrigation with an equal number having ground water. Since other factors were matched as closely as possible, the differences in land value were attributed to water. The second method was multiple regression in which total tract land value and land value per acre for some 160 tracts were related to several factors–soil and topographic conditions, tract size, availability of ground water for irrigation, nearness to elevator, mineral rights, and wheat allotment. Both methods produced approximately the same results–for the period studied the availability of ground water for irrigation contributed $95 to $100 per acre to the value of the land.
The Use of Resistivity Techniques to Delineate Acid Mine Drainage in Ground Water
Authors: Merkel R. H. 
Published: July 2006

ABSTRACTA resistivity survey was run in an area of good geologic control to determine if resistivity is a viable technique for delineating aquifers contaminated with acid mine drainage. Results show that due to the high conductivity of the acid water, it makes an excellent target to define electrically. Aquifers polluted in this fashion were traced from their surface expression back under clays, shales, and coal toward the point of origin. Based on these results along with chemical analysis of streams and ground‐water samples, techniques are presented for the periodic monitoring of the ground water through surface resistivity techniques to determine both the extent and degree of contamination.
Physics of Brine Coning Beneath Skimming Wells
Authors: Sahni Brij M. 
Published: July 2006

ABSTRACTThe purpose of this paper is to elucidate the phenomenon of brine upconing beneath a discharge well partially penetrating an unconfined aquifer in which fresh water is underlain by saline water. In order to predict the maximum uncontaminated fresh water production for given aquifer conditions and well geometry, the potential distribution in the flow region must be known. However, since the partial differential equation describing the flow is nonlinear and so are the boundary conditions, it is not possible to arrive at an exact analytic solution to the problem. Therefore, a less rigorous but tractable approach is to solve this problem using simplifying and physically plausible assumptions. A comparative study is made of the approximate analytic solutions available at the present time and the validity of the assumptions used is evaluated. Factors affecting the stability of the brine cone beneath a skimming well and conditions leading to entrainment of salt water along with fresh water production are also discussed.