bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling Rapid Flow in Aquifers
Authors: Rushton K. R. , Rathod K. S. 
Published: July 2006

ABSTRACTThis paper examines the situation when, due to heavy rainfall, rapid transfer of water occurs in the upper highly permeable region of an unconfined aquifer. The conventional modelling approach of a single transmissivity, which either remains constant or increases with the saturated depth, is shown to be unsatisfactory. Instead it is necessary to consider the aquifer as consisting of two systems with flow always occurring in the primary system but only entering the secondary system during periods of high recharge. This is necessary because the velocities in the different regions of the aquifer are of significantly different magnitudes.The Lincolnshire Limestone aquifer in England is used as an illustrative example. Initially a one‐dimensional approximation to the aquifer is considered so that the different features of the flow mechanism can be examined in detail. The method of dividing the recharge between the primary and secondary systems is shown to be of great importance. Then a preliminary two‐dimensional model of the whole region is considered. The model response is shown to be of the same form as that observed in the field and described in greater detail by Smith (1979).
A Study of the Reuse of Reused Water
Authors: Smith Edgar D. , Sweazy Robert M. , Whetstone George A. , Ramsey R. H. 
Published: July 2006

ABSTRACTLubbock is located in the center of the semiarid High Plains of Texas. Due to a shortage of adequate water‐based recreational facilities in the region, the City Planning Department developed a scheme for converting an eight‐mile intracity canyon into a linear park containing a series of small recreational lakes. Funds amounting to over 11 million dollars were committed to the project by a local bond issue and various governmental organizations.The proposed lake makeup water is unique. Never before has a serious attempt been made to develop recreational lakes utilizing urban runoff and twice‐used reclaimed municipal waste water as the sole source of supply. The majority of the makeup water will be obtained from wells on a farm which has received the major portion of Lubbock's secondary treated sewage since 1938 and used it for irrigation purposes.In order to ascertain the suitability of utilizing this reclaimed sewage effluent for recreational purposes, the Texas Tech University Water Resources Center with the aid of an OWRT grant constructed a model system designed to simulate the lake project. Research performed to date includes algal growth potential studies, water quality analyses, bacteriological assays, viral assays, and fish life studies.
Tracing Subterranean Flow of Sewage‐Plant Effluent in Lower Ordovician Dolomite in the Lebanon Area, Missouria
Authors: Skelton John , Miller Don E. 
Published: July 2006

ABSTRACTIn an area of faulted, cavernous, carbonate rocks of Ordovician age near Lebanon, Missouri, sewage‐treatment‐plant effluent was traced from Dry Auglaize Creek, a losing Ozark stream, to Sweet Blue and Hahatonka Springs in an adjacent basin. Rhodamine WT dye (20‐percent solution) was used to trace the subsurface movement of the effluent. Activated charcoal packets and grab samples of water were collected at 10 sites where dye might be expected to reappear and at a control site outside the area. The leading edge of the dye reached Sweet Blue Spring, a distance of 22.5 km from the injection point, 25 to 30 days after injection, and Hahatonka Spring, at a distance of 29.0 km, 45 to 50 days after injection. The apparent underground travel rate, based on straight‐line distances between injection and resurgence points, was 0.6 to 0.8 km per day.
Aquifer Coefficients Determined from Multiple Well Effects, Fernandina Beach, Florida
Authors: Bentley Craig B. 
Published: July 2006

ABSTRACTOn September 30, 1977, a large industrial plant in Fernandina Beach, Florida, shut down six artesian wells that had been pumping continuously for several weeks from the Floridan aquifer. Two wells continued pumping until November 20, 1977, at which time the shutdown wells were restarted. A water‐level recorder on an observation well recorded the changing water level following shutdown and startup. Pumping rates of the wells ranged from 400,000 to 590,000 cubic feet per day (11,000 to 16,000 cubic meters per day). Distances from the pumped wells to the observation well range from 660 to 7,920 feet (200‐2,420 meters). Analysis of the water‐level data was further complicated because the wells were neither turned off nor restarted simultaneously; during recovery one well was restarted and pumped for several hours; and at the beginning of startup, a well that had been pumping continuously during the shutdown was turned off. The Cooper‐Jacob graphical method, based on the principle of superposition and using values of specific drawdown or specific recovery (s/Q) and weighted logarithmic mean of the distance squared divided by time , was applied to determine the aquifer coefficients for the upper water‐bearing zone of the aquifer. A transmissivity of 30,000 feet squared per day (2,800 meters squared per day) and a storage coefficient of between 2.5 × 10‐4 and 4.0 × 10‐4 were computed.
Well Grouting and Casing Temperature Increases
Authors: Johnson Roy C. , Kurt Carl E. , Dunham George F. 
Published: July 2006

ABSTRACTGrouting of water wells is commonly done to increase the well life and to protect the water supply. When Portland cement‐based grouts cure, a by‐product of the process is heat of hydration which causes increased temperatures in the vicinity of the well casing. Since thermoplastic casing materials lose significant strength at elevated temperatures, it is important to know what range of temperature increases might be associated with the grouting operation.A series of experiments has been performed to determine these temperature increases. Wells were simulated in the laboratory and temperatures monitored throughout the casing‐grout‐soil system. Results indicate that under certain circumstances the casing temperature could increase by as much as 180° F; however, for nominal 1 1/2‐inch grout thicknesses, casing temperature increases between 17° F and 26° F were measured.
Gravity Survey of a Deep Buried Valley
Authors: Stewart Mark T. 
Published: July 2006

ABSTRACTA gravity survey was conducted as part of a ground‐water investigation covering 400 mi2 (1,000 km2) in Outagamie County, northeastern Wisconsin. The objective of the gravity survey was to supplement bedrock topography data obtained from well logs and seismic refraction profiles. The gravity method was chosen as it is a rapid and low‐cost reconnaissance technique, and conditions in the study area were favorable for a successful gravimetric survey. The simple Bouguer gravity values were referenced to a local base station as only relative gravity values were required. The data were interpolated to a regular grid by an inverse‐distance weighted average algorithm. The gravity residual was derived using a five‐ring inverse weighted filtering routine. The residual map accurately reflects the major topographic features of the bedrock surface. A two‐dimensional geologic model fitted to the residual data agrees well with the simple flat plate approximation used to obtain quantitative estimates of glacial drift thickness. Estimates of drift thickness from the gravity data also agree well with bedrock depths obtained from well logs. The most productive drift aquifers are restricted to the major bedrock valleys. Gravity data were coupled with seismic refraction and well data to produce a bedrock elevation map, from which it is possible to predict the extent and distribution of the major drift aquifers.
Overflow Tests Analysed by Theoretical and Numerical Methods
Authors: Rushton K. R. , Rathod K. S. 
Published: July 2006

ABSTRACTThe assumptions inherent in the theoretical analysis of constant drawdown overflow tests are difficult to achieve in practice. This paper shows that, even if there is a restriction in the flow which causes some delay in the achievement of the constant drawdown condition, the theoretical discharge curve is followed once the constant drawdown condition is reached. Recovery tests following overflow are also examined and it is shown that the discharge used in the calculation should be the discharge at the instant that the test is stopped. Further, it is demonstrated that if well and formation losses occur, the aquifer response is distinctly different from that of the theoretical analysis.A brief description is given of an alternative method of analysis using a numerical model. A preliminary study of a field test yields promising results.
Methodology for Monitoring Ground Water at Uranium Solution Mines
Authors: Humenick Michael J. , Turk L. Jan , Colchin Michael P. 
Published: July 2006

ABSTRACTMonitoring the chemistry of ground water near in‐situ uranium leach mines is complicated by chemical variations unrelated to the mining operation that result from (1) spatial differences in the aquifer environment, and hence, in the water chemistry, (2) inconsistent or inadequate sampling procedures, and (3) errors in chemical analyses. Differences in the chemistry of water from place to place in the aquifer should be identified in pre‐mining baseline studies and must be taken into account during monitoring of the leaching operation, because natural waters of chemistry different from that established at a particular well during the baseline sampling period may be drawn into the monitoring well by pumping. The most important factor in developing proper sampling techniques is the configuration of the well and pumping equipment; if the pump intake is set near the point where water enters the well, and if the pumping rate is kept low to reduce turbulent mixing of waters in the well, it is not necessary to pump a full well‐bore volume before collecting a sample. Errors in chemical data can be eliminated by proper storage and handling of the samples and by careful checking of the analyses for chemical balance and eliminating the analyses that do not balance properly. Interpretation of the chemical data should be made only after assuring that these monitoring problems have been taken into account.
Ground‐Water Management in the High Plainsa
Authors: Wickersham Ginia 
Published: July 2006

ABSTRACTThe High Plains region of mid‐America depends on ground water to a huge extent. A review of three States‐Texas, Colorado and Oklahoma—shows a disparity in ground‐water management in the region. Texas landowners own the ground water as a property right and the emphasis is on local management districts to control ground‐water use. Colorado, in contrast, has State control of ground water and regulation by permit from the State Engineer. Oklahoma is unique in tightly regulating ground water through limitations on pumpage, while still adhering to ownership by the individual landowner.In spite of these differences, six of the High Plains States have united in a joint effort to study the ground water in the Ogallala. A $6 million study funded by EDA will evaluate the economic impacts of ground‐water mining and determine future water resources management in the region.
High Water Levels in Ground‐Water Dominant Lakes — A Case Study from Northwestern Wisconsin
Authors: Rinaldo‐Lee M. B. , Anderson M. P. 
Published: July 2006

ABSTRACTAn investigation into the cause of high lake levels during the early 1970's in a ground‐water dominant lake in northwestern Wisconsin was conducted from December 1976 to July 1978, in part to address allegations by shoreline property owners that regulation of water levels in a reservoir 2.4 km south of the lake had caused the high lake levels. High lake levels also coincided with above average precipitation. Data collected during the study allowed the definition of the ground‐water flow system around the lake and the calculation of the water budget for the lake. Field data indicated that there is no ground‐water flow between the reservoir and the lake and that ground water flowing out of the reservoir is intercepted by a trough in the potentiometric surface. The trough is probably oriented along a permeable fault zone or a buried river valley. A ground‐water flow model was used to determine whether increased recharge rates of the magnitude that probably occurred as a result of above average precipitation in the early 1970's would be sufficient to account for the observed rise in lake level or whether regulation of the water level in the reservoir could be expected to affect lake level.
Convective Heat Transfer in Selected Geologic Situations
Authors: Kilty Kevin , Chapman David S. 
Published: July 2006

ABSTRACTThere are many geological situations where moving ground water transfers a significant amount of heat. Yet, while convective heat transfer is a common phenomenon, it is very difficult to treat analytically. In this paper we present a simple model of convective heat transfer in porous materials and a numerical method of solving the model. The model is then applied to three diverse field situations: (1) a thermal anomaly on the Hartville uplift in eastern Wyoming; (2) a fault‐controlled hydrothermal system near Monroe, Utah; and (3) the Luanshya copper mine in the Republic of Zambia. In each case heat transfer by moving ground water is shown to explain the observed thermal anomalies satisfactorily. Our results indicate that in certain situations the effect of ground‐water flow needs to be considered in making local and regional assessments of heat‐flow data. Furthermore, temperature measurements can be very useful in estimating aquifer recharge, particularly when thermal conductivity and structural information are available.
The Deccan Basalts of Maharashtra, India —Their Potential as Aquifers
Authors: Deolankar S. B. 
Published: July 2006

ABSTRACTIn order to study the potential of the Deccan basalts as aquifers, the properties of transmissivity and storativity must be considered. Analysis of large‐diameter dug wells tapping unconfined aquifers in the Deccan basalts shows that there exists a relationship between porosity and specific yield. The aggregate porosities of weathered basalts, vesicular basalts and fractured‐jointed basalts are respectively up to 34%, 50%, and 15%. On the contrary, specific yield has a maximum value of 7%, 4%, and 1% respectively. In relation to aggregate porosity the specific yield is low suggesting that in Deccan basalts effective porosity constitutes only a small fraction of aggregate porosity. It is found that this effective porosity is about 7%. The weathered basalts and vesicular basalts have higher transmissivities than fractured‐jointed basalt and, therefore, form better aquifers. The variation in transmissivity values in various directions, and from point to point, indicates that the Deccan basalts are hydrogeologically anisotropic and heterogeneous in nature.
Ground‐Water Use for Cooling: Associated Aquifer Temperature Changes
Authors: Lippmann Marcelo J. , Tsang Chin Fu 
Published: July 2006

ABSTRACTIn steam‐electric power plants, large volumes of surface waters are used for cooling the plant's condensers. There, approximately two‐thirds of the energy produced by the fuel is removed as waste heat. This heat is carried away by the cooling waters, is dispersed into the atmosphere or surface‐water bodies, and is lost for other potential uses. When condenser cooling systems such as towers or ponds are used, there is also a considerable net loss of water through evaporation.Injection and storage of spent cooling waters underground would reduce the evaporative (consumptive) losses to the atmosphere. Later, these waters could be recovered for use in heating and in industrial or agricultural applications. The resulting conservation of energy and water may make such a project economically feasible in the near future as the costs of water and fuel increase.In this paper, we review the use of ground water from a confined aquifer for this application and analyze a simple configuration of one withdrawal and one injection well to determine: (1) the areal extent of temperature changes caused by reinjection of spent cooling waters into the aquifer from which they originated; and (2) how long it would take for the water to become too hot to use for cooling.
Monitoring Ground‐Water Contamination at a Fly Ash Disposal Site Using Surface Electrical Resistivity Methods
Authors: Rogers Robert B. , Kean William F. 
Published: July 2006

ABSTRACTGround‐water quality has been monitored at a fly ash disposal site. The monitoring technique consists of electrical resistivity soundings, and profiles in conjunction with analysis of water samples from 33 wells on the site. In addition laboratory measurements were made on samples from the well borings to determine the changes in resistivity of each lithology as a function of water saturation, and the temperature and conductivity of the pore fluid.For a line approximately perpendicular to the ground‐water flow, we were able to detail the subsurface lithology using electrical sounding, and in conjunction with the laboratory studies, it was possible to determine the vertical and horizontal extent of the contamination for that cross section.Electrical profiles, which were taken on a monthly basis, were able to monitor the changing concentration of leachate after the profiles were corrected to a common ground‐water temperature.
Ground‐Water Modeling: Applicationsa
Authors: Mercer James W. , Faust Charles R. 
Published: July 2006

ABSTRACTThe numerical models used in ground‐water studies are general computer programs that can be applied to a variety of hydrogeological conditions. These programs are based on approximations to the governing partial differential equations for ground‐water flow and transport. To use these models requires an understanding of the physical problem and field data. Although program input data and output results are quantitative, the appropriate application of numerical models remains a partly subjective procedure. To use models, the hydrologist must assess the merits of alternative numerical methods, evaluate available data, estimate data where missing or absent, and interpret computed results. The review of previous model applications can provide valuable insight on how these tasks may be approached.
Control of Ground‐Water Salinity, Orange County, California
Authors: Hammer Mark J. , Elser Gordon 
Published: July 2006

ABSTRACTThe Orange County Water District in Southern California imports approximately 75 percent of its supply from aqueducts drawing waters from the Colorado River and Northern California. Twenty‐five percent comes from natural flow in the Santa Ana River and local precipitation. Only about one‐half of the aqueduct water is treated and distributed in pipelines. The other one‐half is applied to infiltration basins and ponds for ground‐water recharge. This allows communities within the District to draw ground water as their major supply, which is supplemented by aqueduct water purchased after treatment by the Metropolitan Water District of Southern California. The economic advantages of ground‐water recharge, as opposed to direct use of surface supplies, include eliminating water treatment, minimizing the size of pipe networks to distribute potable supplies, and reducing the requirement for storage reservoirs. However, using the basin aquifers as a reservoir to balance cyclic supply and demand creates two possible problems: excessive pumping lowers the fresh‐water table below sea level, and infiltration can result in a gradual increase in the level of dissolved salts in the ground water. Sea‐water intrusion has been greatly reduced by injection wells that provide a hydraulic barrier between the salt water and fresh inland water. Salt accumulation in the basin is a more serious long‐term problem since the salinity in the Colorado River water is increasing. Greater use of less salty Northern California water and reducing unwanted seepage of waste waters containing high dissolved solids are two of the remedial measures being implemented at present.
Pumping Test Analysis with a Handheld Calculator
Authors: Rayner Frank A. 
Published: July 2006

ABSTRACTThe time‐consuming curve construction and, in some cases, curve matching, and the gross approximations of aquifer geohydrologic properties, can be supplanted by a simple, speedy, accurate, and inexpensive analysis of pumping test data by a handheld programmable calculator.With such calculators—in actuality, minicomputers‐pumping test data can be analyzed within seconds, while the test is ongoing, and pumping test time and expense can be reduced, while still securing representative values for transmissivity and storage coefficients.
Ground‐Water Flow and Uranium in Colorado Plateau
Authors: Ortiz N. V. , Ferentchak J. A. , Ethridge F. G. , Granger H. C. , Sunada D. K. 
Published: July 2006

ABSTRACTThe precipitation of humates at the interface between a humic acid solution and an aluminum potassium sulfate solution was studied in porous media models to gain some insight into the deposition of Colorado Plateau type uranium deposits. The effects of variable flow rates, porous‐media layering, mudstone lenses, fluid density differences, and geochemical reactions on the flow phenomenon and the resulting precipitate were evaluated. A numerical model was developed to predict the shape and location of the interface where precipitation occurs. The numerical model was verified by comparing its predictions with the results obtained from the porous media model. The association of precipitate bands with modeled sedimentary features and the similarities between these precipitate bands and actual deposits in the Colorado Plateau suggest that these model studies provide data useful both in understanding and predicting the relations between tabular ore deposits and ground‐water flow patterns.
A Comparison of Nitrogen in Shallow Ground Water from Sewered and Unsewered Areas, Nassau County, New York, from 1952 through 1976a
Authors: Katz Brian G. , Lindner Juli B. , Ragone S. E. 
Published: July 2006

ABSTRACTMedian nitrogen concentrations of ground water and water from streams in Nassau County were statistically analyzed on an areal and temporal basis and by individual well to compare concentrations of nitrogen in ground water beneath sewered and unsewered areas. The comparison is discussed in terms of hydrogeologic conditions and major point and nonpoint sources of nitrogen.Although no significant differences in median nitrate concentrations during the 25‐year period of record were observed between the sewered and unsewered areas, recent (1972–76) ammonium and nitrate data suggest a relative improvement in water quality in the sewered area. This finding is based on (1) significantly lower ammonium and nitrate concentrations in stream water of the sewered area during base flow, (2) significantly lower median ammonium concentrations in ground water in the sewered area, (3) significant decreasing long‐term nitrate trends in water from 8 of 13 wells in the sewered area where records were sufficient for analysis, and (4) significantly lower median nitrate concentrations near the water table beneath the sewered area.The lack of significant difference between median nitrate concentrations in the sewered and unsewered areas may be in part due to sampling bias and to the considerable length of time necessary for ground water in the sewered area, which was contaminated by cesspool and septic‐tank effluent before sewering, to reach a point of discharge in a stream or bay.In addition, ammonium leached from landfills and nitrate originating from nonpoint sources such as fertilizers and animal wastes, cannot be removed by sewers and may be obscuring water‐quality improvements brought about by sewering.