bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ground‐Water Management in Basaltsa
Authors: Shelton M. L. 
Published: March 2006

AbstractBasalts are a major source of ground water throughout the Columbia River Plateau region of the Pacific Northwest. Development and management of ground water in these basalts are complicated by the spatial variability of the hydrologic characteristics of the deep, stratified lava flows, but new irrigation developments and municipal and industrial water needs are placing increasingly larger demands on the ground‐water resource. Water management decisions are aided by individual basin studies that contribute to greater understanding of the regional ground‐water system. A distributed‐system multiple‐storage model for the Deschutes River Basin, Oregon, reveals the magnitude of spatial differences in ground‐water recharge, storage, and discharge for this watershed. Input‐output analysis elucidates the functional characteristics of the basin groundwater system, and it identifies the presence and magnitude of interbasin linkages in the ground‐water system. Implementation of ground‐water development strategies based on storage and transmission characteristics simulated by the model demonstrates that basin or regional perspectives are necessary to fully utilize ground‐water storage in basalts.
Cyclic Storage: A Preliminary Assessment
Authors: Lettenmaier Dennis P. , Burges Stephen J. 
Published: March 2006

AbstractThe performance of a simplified water resource system consisting of a single surface reservoir and adjacent aquifer storage operated as a coupled flow buffering device is investigated on an annual scale to provide insight into the most important physical and climatic (streamflow) parameters governing cyclic storage performance. The hypo thetical system is fully characterized by aquifer capacity, pumping and recharge capacity, surface storage size, annual demand, and reservoir inflow statistics, including annual mean, coefficient of variation, skew coefficient, lag one correlation coefficient, and Hurst coefficient. System performance under a range of these parameters is reviewed via Monte Carlo simulation; for the cases considered system performance is almost always limited by total system storage (sum of surface and aquifer storage). A preliminary economic analysis indicates that the cost of providing flow buffering via development of subsurface storage is about an order of magnitude less than for surface storage in the cases considered.
Sulfate‐Reducing Bacteria in Ground Water from Clogging and Nonclogging Shallow Wells in the Netherlands River Region
Authors: van Beek C.G.E.M. , van der Kooij D. 
Published: March 2006

ABSTRACTThe majority of well fields in the river region in the Netherlands, where anaerobic water is withdrawn from the shallow aquifer, have problems with well clogging. In order to test the supposition that sulfate‐reducing bacteria play a role in this clogging process, sulfate‐reducing bacteria in water from wells on well fields with and without the occurrence of clogging were enumerated. In water withdrawn from nonclogging wells, the Most Probable Number of sulfate‐reducing bacteria averaged 5 per 100 ml, whereas in wells subject to clogging, the number averaged 25 per 100 ml. A statistical analysis by Wilcoxon's order test confirmed that a significant difference exists between the numbers of sulfate‐reducing bacteria in clogging and nonclogging wells. The mechanism whereby sulfate‐reducing bacteria contribute towards this type of well clogging is as yet unclear.
Analysis of Leaky Aquifer Pumping Test Data: An Automated Numerical Solution Using Sensitivity Analysis
Authors: Cobb P. M. , McElwee C. D. , Butt M. A. 
Published: March 2006

ABSTRACTThe Kansas Geological Survey is pursuing an effort to automate some of the more common methods of aquifer pumping‐test analysis. This paper discusses the results of work done on the leaky artesian aquifer as defined by Hantush and Jacob (1955). The paper covers the basic theory of the aquifer type, the numerical solution of the leaky artesian‐well function, and the methodology of achieving the “best fit” parameters in the least squares' sense. Several data sets are used to demonstrate the applicability of the proposed technique. These examples indicate the generally satisfactory results produced by the automated analysis documented here.The algorithm has good convergence properties. Initial estimates for the aquifer parameters may vary by about three orders of magnitude above or below the correct values. For typical data sets the rms fitting error should be less than a few tenths of a foot. If this is not the case, one is probably not dealing with a simple leaky aquifer. This method of pumping‐test analysis does not eliminate the role of an experienced hydrologist to define the local hydrogeology and aquifer type. However, once the decision is made as to which aquifer configuration is being observed, this program will, in a quick and unbiased fashion, give an accurate assessment of the leaky‐aquifer parameters within the limits of the theoretical approximations and the data quality.
Evaluation of Electromagnetic Methods for Rapid Mapping of Salt‐Water Interfaces in Coastal Aquifers
Authors: Stewart Mark T. 
Published: March 2006

ABSTRACTIn coastal areas salt‐water intrusion represents a significant threat to water quality in coastal aquifer systems. The electromagnetic method evaluated in this study proved to be rapid, very inexpensive, and it yields results which agree well with geologic and geochemical surveys using direct sampling. The instrument reads directly in conductivity units and the depth of investigation is constant for a particular spacing and orientation of the receiver and transmitter coils. Data can be obtained and interpreted by personnel with little technical training. Data interpretation normally involves producing terrain conductivity contour maps, but quantitative solutions can be obtained where the geoelectric section can be reasonably approximated by a two‐layer section. Some problems were experienced with interference. However, interference sources usually were very localized and could be avoided.This study, conducted in two areas of Florida, demonstrates that the EM conductivity method is very useful for rapid, inexpensive ground‐water surveys where the objective is to locate zones of conductive pore fluids at depths less than 30–40 meters. Although interpretation is indirect and qualitative, neither data aquisition nor interpretation require special training. This characteristic of the EM method makes it very suitable for use by agencies where highly‐trained technical personnel are not available.
Numerical Simulation of Thermal Energy Storage Experiment Conducted by Auburn University
Authors: Sykes J. F. , Lantz R. B. , Pahwa S. B. , Ward D. S. 
Published: March 2006

ABSTRACTA multidimensional, finite‐difference model for ground‐water flow and heat transport is used to analyze the thermal energy storage experiment conducted by Auburn University in Mobile, Alabama. The experiment consisted of three stages–namely, injection, storage and recovery occurring for 80, 51 and 41 days, respectively. This application demonstrates the validation evidence that the model adequately and accurately simulates the field experiment. The numerical model includes the effects of: hydraulic anisotropy, thermal convection and conduction, and heat loss to the adjacent confining strata. Observed aquifer isotherms at the end of each stage are compared with predicted values on a cylindrical grid situated about the well. The degree of vertical discretization used in the model is shown to impact the predicted temperature profiles at each stage, but has minimal effect on the recovery water temperature.
In‐Situ Determination of Three‐Dimensional Aquifer Permeabilities
Authors: Way Shao‐Chih , McKee Chester R. 
Published: March 2006

ABSTRACTIn conventional methods of aquifer tests, homogeneous and isotropic formations are assumed. In many instances, however, aquifers are anisotropic. To resolve this problem, three‐dimensional flow equations in homogeneous, anisotropic and leaky aquifers are derived. With the equation and method outlined in the report, we can determine the three components of directional permeability (x, y, and z) in the presence of leakage, and determine the statistical distribution of fractures and stream channels. Field tests that verify our theory are presented.
Nitrate Distribution in the Ground Water of the Alliston Region of Ontario, Canada
Authors: Hill A. R. 
Published: March 2006

ABSTRACTNitrate‐N concentrations during the Summers of 1980 and 1981 exceeded 10 mg/1 in 68 of the 164 ground‐water samples collected from a shallow water‐table aquifer underlying a sand plain near Alliston, Ontario. Three extensive zones of nitrate contamination were associated with major potato‐growing areas on the sand plain. Nitrate concentrations were positively correlated with both the percentage area of heavily fertilized crops (potatoes, corn, sod and asparagus) and nitrogen fertilizer application rates in the vicinity of ground‐water sampling sites. Chloride levels in ground water exhibited a positive association with KCl fertilizer application rates. Ground water under potato fields had relatively consistent C1/NO3‐N ratios despite considerable variations in nitrate‐N and chloride concentrations. Ground water with a low nitrate content was found beneath forest and permanent pasture. These data suggest that the use of commercial nitrogen fertilizer is a major source of nitrate in the aquifer.
Degradation of Phenolic Contaminants in Ground Water by Anaerobic Bacteria: St. Louis Park, Minnesota
Authors: Ehrlich G. G. , Goerlitz D. F. , Godsy E. M. , Hult M. F. 
Published: March 2006

ABSTRACTCoal‐tar derivatives from a coal‐tar distillation and wood‐treating plant that operated from 1918 to 1972 at St. Louis Park, Minnesota contaminated the near‐surface ground water. Solutions of phenolic compounds and a water‐immiscible mixture of polynuclear aromatic compounds accumulated in wetlands near the plant site and entered the aquifer. The concentration of phenolic compounds in the aqueous phase under the wetlands is about 30 mg/1 but decreases to less than 0.2 mg/1 at a distance of 430 m immediately downgradient from the source. Concentrations of naphthalene (the predominant polynuclear compound in the ground water) and sodium (selected as a conservative tracer) range from about 20 mg/1 and 430 mg/1 in the aqueous phase at the source to about 2 mg/1 and 120 mg/1 at 430 m downgradient, respectively. Phenolic compounds and naphthalene are disappearing faster than expected if only dilution were occurring. Sorption of phenolic compounds on aquifer sediments is negligible but naphthalene is slightly sorbed. Anaerobic biodegradation of phenolic compounds is primarily responsible for the observed attenuation. Methane was found only in water samples from the contaminated zone (2‐20 mg/1). Methane‐producing bacteria were found only in water from the contaminated zone. Methane was produced in laboratory cultures of contaminated water inoculated with bacteria from the contaminated zone. Evidence for anaerobic biodegradation of naphthalene under either field or laboratory conditions was not obtained.
Approximating Pollutant Transport to Ground Watera
Authors: Enfield Carl G. , Carsel Robert F. , Cohen Stuart Z. , Phan To , Walters David M. 
Published: March 2006

ABSTRACTThree simplistic models are developed for evaluating the transport of organic pollutants through soil to ground water. The models consider mobility and first‐order degradation. The first calculates linear sorption/desorption of the pollutant and first‐order degradation without considering dispersion. The second is similar to the first but also considers dispersion. The third considers nonlinear sorption following a Freundlich equation and first‐order degradation but does not consider dispersion. The models are compared to field data for the pesticides aldicarb and DDT. The models projected a lower mobility for DDT than was observed in the field.
ISOTOPES IN GROUND‐WATER INVESTIGATIONS
Authors: Toran Laura 
Published: March 2006

AbstractDuring the past 20 years, hydrologists have made increasing use of isotopes to obtain a better theoretical and practical understanding of ground water. The distribution of isotopic species in water provides information on sources of ground water, on flow paths and mixing, and on physical and chemical characteristics of aquifers.Numerous examples in the literature illustrate the techniques and applications of isotopes to ground‐water studies. Isotopes have helped solve problems as diverse as what is a fair tax rate for people using imported water in a California water district, and why Venice is sinking. Demands are increasing for better understanding of hydrologic systems to facilitate management of water as a resource, and to evaluate environmental problems. Thus, we can anticipate isotopes will be used more and more in hydrologic studies.
The Use of Microorganisms as Ground‐Water Tracers: A Review
Authors: Keswick Bruce H. , Wang De‐Shin , Gerba Charles P. 
Published: March 2006

ABSTRACTMicrobial contamination of ground water results in numerous disease outbreaks each year. Tracing their movement in ground water is therefore essential. Bacteria, viruses, yeasts and spores have been used for this purpose and to trace underground movement of water in much the same manner as chemical tracers are used. Chemical tracers do not always reflect the movement of microorganisms in ground water. The use of certain bacteria and animal viruses is undesirable due to their pathogenic potential and difficulties in their differentiation from background, naturally‐occurring organisms. Bacterial viruses appear to be the microorganisms most suited as a microbial tracer because of their size, ease of assay and lack of pathogenicity. Bacteriophages have been used to trace ground‐water movement over distances of 1,600 meters and can be used under a variety of conditions.
Hydraulic Conductivity of a Glacial Till in Albertaa
Authors: Hendry M. James 
Published: March 2006

ABSTRACTSoils underlain at shallow depths (less than 1 m, 3 ft) by glacial till are generally considered undesirable for irrigation because of their unfavourable internal drainage characteristics. In some areas of southern Alberta, Canada, soils developed upon shallow tills have been irrigated successfully for over 60 years with no adverse effects on the soil. An investigation was conducted to describe the hydro‐geologic properties of till under one of these areas and to assess the properties with regard to drainage. Study techniques consisted of detailed test drilling and sampling, excavation of test pits, installation and monitoring of ground‐water instrumentation, field and laboratory hydraulic conductivity testing and tritium analyses of ground‐water samples. Two fracture sets were found in this till. Both sets of fractures produce secondary permeabilities which mask the low hydraulic conductivity of the till matrix (10−10m·s−1). Small‐scale fractures which have a fracture spacing of approximately 10 mm (0.4 in.) have an apparent mean hydraulic conductivity of 5 × 10−9m·s−1, whereas large‐scale fractures which have fracture spacings from 20 mm (0.8 in.) to over 630 mm(2 ft) have an apparent mean hydraulic conductivity of approximately 2 × 10−7m·s−1. The high hydraulic conductivity of the large‐scale fractures was corroborated by tritium analyses of ground‐water samples. Tritium analyses also indicate the presence of recent water at depth in the till. The large‐scale fractures, which control the bulk hydraulic conductivity of this till, provide conduits through which infiltrating water can be transmitted to the ground‐water regime. These fractures are believed to be the reason why this land has remained irrigable for over 60 years.
Determining Hydraulic Conductivity Distributions in a Mountainous Area Using Mathematical Modeling
Authors: Jamieson Gordon R. , Freeze R. Allan 
Published: March 2006

ABSTRACTMeager Mountain is a recently‐active andesite‐dacite volcano situated 160 km NNW of Vancouver, British Columbia. The mountain is presently being jointly evaluated by the Geological Survey of Canada and the British Columbia Hydro and Power Authority as a potential geo‐thermal resource. Limited existing and field‐generated geological and hydrogeological data were employed to evaluate the ground‐water flow regime at the study area. Mathematical modeling was carried out to determine the feasible range of ground‐water‐flow characteristics in the area. Field observations indicate that the water table is located at an intermediate elevation in the mountain system with the discharge area confined to the portion of the valley covered by unconsolidated deposits. Water balance calculations for the Lillooet River basin and baseflow determinations in the Meager Creek basin indicate that 14 to 17% of the total precipitation recharges the ground‐water system. Various possible geological configurations were mathematically modeled with the water‐table configuration and recharge rates restricted to the above ranges. The model results were used to predict the variations in the hydraulic conductivity in each geological formation. The results fell into a discrete range of values thought to be within an order of magnitude of the actual values.
Lower Hawthorn Aquifer on Sanibel Island, Florida
Authors: Motz Louis H. 
Published: March 2006

ABSTRACTIn 1977, the Island Water Association (IWA) on Sanibel Island, Florida, was concerned that the total dissolved solids concentrations in several wells in its well field were increasing and might cause the blended raw water to exceed the design capacity of its electrodialysis plant. Test wells were drilled several miles west of the existing well field, and two pumping tests, one at the site of the test wells and the other in the existing well field, were run. Average values for the transmissivity (T), storage coefficient (S), and leakance (K′/b′) of the lower Hawthorn aquifer were determined to be T = 1,290 ft2/d (119 m2/d), S = 2.7 × 10−5, and K′/b′= 7.47 × 10−6 (1/d). The results of the pumping tests and other findings indicated that pumpage from the lower Hawthorn aquifer was being derived from artesian storage in the aquifer and from vertical leakage into the aquifer from adjacent formations. It was estimated that the IWA would be able to recover usable water from the lower Hawthorn aquifer for about 5 more years by drilling new wells in the vicinity of the test wells and in other nearby areas that might be determined to yield usable water. After this period of time, it likely would become increasingly difficult, if not impossible, to obtain large quantities of usable water from the lower Hawthorn aquifer, unless significant quantities of water could be found in areas in which few data were then available. The principal recommendations, which subsequently were acted upon by the IWA, were to conduct drilling and testing in the lower Hawthorn aquifer several miles west of the test wells and to investigate the underlying Suwannee aquifer and deeper zones as possible sources of large quantities of brackish water.
Bailing and Construction Considerations for Deep Aquifer Monitoring Wells on Western Oil Shale Leases
Authors: Kelly K. E. 
Published: March 2006

ABSTRACTWater quality data collected from monitoring wells in the Piceance Creek Basin oil shale area can be significantly influenced by well design and sampling techniques. Many of these influences can be attributed to hydrogeologic complexities, which can have notable variations on a fairly local scale. To adequately address these complexities, a site‐specific characterization of the hydrogeology is necessary. This is particularly important for specifying well construction details of monitoring wells for a ground‐water quality monitoring program.Data collected during the bailing of deep aquifer wells on Federal Prototype Oil Shale Lease Tract C‐a indicates the need for consistent and representative sample collection depths. Appreciable changes in water quality can be induced by variations in sample collection depths. In addition, unrepresentative data can be obtained due to the incorrect selection of intervals to be sampled in the well. Care must be taken to sample consistently from the same depth and aquifer interval during each and every sampling effort.Studies such as these provide necessary background information for developing ground‐water monitoring guidelines in the oil shale region. Sampling procedures must be consistent to assure representative data collection. In addition, wells should be designed and completed according to the local hydrogeology and the specific goals of the monitoring program.
A Repeated Pulse Technique for Determining the Hydraulic Properties of Tight Formations
Authors: Walter G. R. , Thompson G. M. 
Published: March 2006

ABSTRACTSlug and bailer tests are being used increasingly to evaluate the hydraulic properties of “tight” geologic units. Although these pulse methods of stressing a system are used typically only on single wells, the repeated pulse method described here stresses the system in the same manner, but the response is measured in observation wells. This type of pulse test yields much the same information as conventional pumping tests, but it is easier to perform in very low permeability units.The observation well response hydrographs are analyzed by curve‐matching techniques. In general, a unique set of type curves must be computed for each pulse test. These type curves are computed easily if the pulsed well is treated as a line‐source (or sink). The accuracy of the value of transmissivity (T) determined from the line‐source type curves compared to using the finite‐diameter well solution depends both on the pulsed well radius (rc) and the time interval between pulses (Δt). If TΔt/rc2 is maintained greater than 50, then T determined from the line‐source solution will be within 25% of that determined from more accurate, but computationally inconvenient, finite‐diameter well type curves.The repeated‐pulse test technique was applied to an experimental well array completed in the Conasauga Shale Formation at Oak Ridge National Laboratory. Values of transmissivity determined by the repeated‐pulse method agreed well with the results of slug tests performed on each well individually, and in addition, provided information on storage coefficients and anisotropy at the site.
Hydrogeology of Pipeline Canyon, Near Gallup, New Mexicoa
Authors: Raymondi Richard R. , Conrad Ronald C. 
Published: March 2006

ABSTRACTThe principal water‐bearing units (in descending stratigraphie order) in Pipeline Canyon are the alluvium, the Dilco Coal Member of the Crevasse Canyon Formation, the Torrivio Sandstone Member of the Gallup Formation, and the Upper and Lower Gallup Sandstones. Presently, the alluvium is recharged by a perennial, southward‐flowing stream sustained by mine dewatering discharge in addition to natural precipitation and runoff. Localized infiltration has created ground‐water mounds in the alluvium. Artesian conditions may exist in sandstone units which are adjacent and hydraulically connected to the alluvium in these areas. Basement faults have produced the Fort Wingate and Pipeline Canyon lineaments which intersect in the area of investigation. Fault‐related fracturing of the sandstones allows for significant ground‐water recharge via the overlying alluvium. Flow in the sedimentary formations is generally to the northeast, while the alluvial system flows to the southwest. The natural water quality for the aquifers in the area is dominated by sodium and sulfate ions. However, complete characterization of the natural water quality is complex because of ground‐water contamination by acidic tailings fluids from a local uranium mill.