bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Nitrate in the Ground War in the Delaware Coastal Plain
Authors: Robertson Frederick N. 
Published: July 2006

ABSTRACTData from over 800 well samples collected and analyzed during a study of ground‐water quality in Sussex County, Delaware revealed that the water‐table aquifer contains excessively high concentrations of nitrate in several areas. Over 20 percent of the wells sampled contained concentrations that exceeded 45 milligrams per liter (mg/l), and in many areas, over 50 percent of the wells sampled exceeded 45 mg/l.Sussex County is part of the Atlantic Coastal Plain Province, geologically consisting of a series of unconsolidated sands, gravels, silts, and clays that contain extensive ground‐water reserves of generally high quality. On the basis of iron and nitrate concentrations, two major areas of differing water quality were delineated: one in which the ground water contained variable concentrations of nitrate with low concentrations of iron (<0.2 mg/l), and another in which it contained large concentrations of iron (>2.0 mg/l) and little detectable nitrate.Nitrate concentrations ranged from zero to 224 mg/l; average and median values determined for the area of nitrate occurrence were 33.9 mg/l and 25 mg/l respectively. Treatment of the nitrate data allowed depicting of 19 areas of possible excessive nitrate contamination. Nitrate occurrences were closely related to land use, soil permeability, water‐table depths and aquifer chemistry. The greatest incidence of high nitrate concentrations was associated with confined feeding operations. Other nitrate sources are septic tank effluent, natural and chemical fertilizers, foliage in forests, and precipitation.
Spring Discharge in Relation to Rapid Fissure Flow
Authors: Smith Edward John 
Published: July 2006

ABSTRACTRapid fissure flow has been recognised as an important factor in understanding the hydraulic behaviour of the Lincolnshire Limestone aquifer of eastern England. A study of the hydrogeology of a Lincolnshire Limestone spring‐fed catchment enables three zones of discharge to be defined, based on their relative elevation along the valley floor. Comparison of the discharge characteristics of each zone reveals the existence of rapid ground‐water flow associated with a discrete fissure system. Comparison of spring discharges and ground‐water storage during a period of “high,”“low” and “typical” recharge enables a conceptual flow model of the aquifer to be constructed. A two‐layered model is proposed, in which the secondary zone (upper unit) is characterised by higher transmissivity and lower storativity than the primary zone (lower unit). In addition, there is evidence of a rapid increase in transmissivity with water‐table elevation in the secondary zone. The areal distribution of the secondary zone is associated with a net work dry valleys. The spatial distribution of the two zones is explained by geological structure, lithological variations and the post‐glacial history of the area. A two‐layered model is developed with these concepts in mind in order to simulate the spring discharges. Once proven, the model can be integreated with the regional hydrogeology and incorporated into existing digital models of the aquifer.
Hydrogeological Processes and Chemical Reactions at a Landfill
Authors: Baedecker Mary Jo , Back William 
Published: July 2006

ABSTRACTChemical and isotopic analyses were made of water from wells in and downgradient from a landfill to determine chemical and isotopic effects of generation and migration of leachate on ground water. The distribution and wide concentration range of oxygen and methane permit the delineation of an anaerobic zone, a regional oxygenated zone and an intermediate zone. The ratio of reduced nitrogen to nitrate indicates location of reducing fronts as the leachate migrates. The pH of the native ground water is low (≥5.0) primarily because of the low pH of rainfall and the lack of calcareous or other soluble minerals in the aquifer material. The pH is higher (∼6.6) in the leachate because of generation of carbon dioxide, ammonia, and methane. The native ground water has a low TDS (80 mg/l) while the leachate has an average TDS of 2800 mg/l and is primarily a NaHCO3 type water. Sulfate concentrations are extremely low and H2S was not detected.We suggest that a major source of cations may be their exchange from the clays by the ammonium generated in the leachate. High concentrations of Fe and Mn are attributed to a source in the refuse but more important to reduction of oxide cements and coatings resulting from degradation of organic matter. The main source of bicarbonate is from organic degradation with minimal CO2 from the soil zone. At one landfill site 52% of the total alkalinity is attributed to organic compounds, mainly organic acid anions. The δ13C of bicarbonate in the leachate is exceedingly heavy (+18.400/00) which results from fractionation during the formation of methane. The 10 per mil deuterium enrichment of water may be due to decomposition of deuterium‐enriched compounds and bacterial processes that preferentially consume the lighter hydrogen isotope.
The Application of a Digital Model for Evaluating the Bedrock Water Resources of the Maumee River Basin, Northwestern Ohioa
Authors: Naymik Thomas G. 
Published: July 2006

ABSTRACTIncreasing population and industrial development in northwestern Ohio indicated the need for an evaluation of the bedrock ground‐water resources of the region. A digital ground‐water model was designed and used as a tool for predicting water‐level declines resulting from projected ground‐water withdrawal. Potentiometric surfaces, keyed to historic, accelerated, and peak projected ground‐water withdrawals, were predicted by decades to the year 2036. These withdrawals at the calculated rates will cause severe overdrafts at Lima, Toledo, and Findlay, Ohio, and at Ft. Wayne, Indiana, by the year 2036.
Electric Analog Model Study of Aquifer in Krishni‐Hindon Interstream Region, U.P., India
Authors: Gupta C. P. , Thangarajan M. , Rao V.V.S. Gurunadha 
Published: July 2006

ABSTRACTOverexploitation of ground water in Krishni‐Hindon interstream region (Lat. 29°05′N–29°29′N and Long. 77°19′E–77°32′E) in Uttar Pradesh, India, prompted us to carry out aquifer modeling studies. The area lies in Gangetic alluvial plain. The interconnections in the phreatic aquifer and the lower semiconfined aquifer led to the assumption of a single‐story aquifer for which an R‐C analog model was constructed.The input‐output quantities in the model have been simulated using current/voltage generators and current sinks which are appropriately programmed in time‐domain with the help of wave‐form synthesizers for a realistic representation of the field system.The model study shows that the aquifer can sustain the present output rate of 200 mcm/year without much damage to the ground‐water regime. In another scheme, an annual increase of 5% in exploitation rate, shows deleterious effects on the aquifer. Decreased rainfall/droughts would worsen the situation.The influence of hydraulic connectivity between the aquifer and the Krishni‐Hindon river system is quite significant. If the present exploitation rate were to continue for 20 years, the annual inflow to the aquifer from rivers is estimated to increase by about 36.0 mcm.More hydrogeological data is required for further validation and refinement of the model.
Programmable Hand Calculator Programs for Pumping and Injection Wells: I — Constant or Variable Pumping (Injection) Rate, Single or Multiple Fully Penetrating Wells
Authors: Warner Don L. , Yow M. Gene 
Published: July 2006

ABSTRACTSmall programmable calculators have recently become available that will allow many routine pumping or injection well calculations to be made rapidly, accurately and inexpensively. Programs and example calculations are given for the exponential integral and multiple well‐multiple rate pumping or injection well equations using water well and oilfield units. The programs are for the TI 59 card programmable calculator.
A Simplified Statistical Sequence Applied to Routine Water Quality Analysis: A Case History
Authors: Alther George A. 
Published: July 2006

ABSTRACTA sequence of simple statistical tests was used to interpret the data from a routine water sampling project for a stream that was contaminated with effluent from a sewage treatment plant. The contamination of this stream was apparent from the murky condition of the water and its pungent odor. The outlet of the sewage treatment plant enters the stream at its origin.The chemical variables analysed were Ca, Mg, Na, K, Cl, nitrates, TDS, and hardness. Background data from other streams in this drainage basin and data from the stream under investigation were subjected to cluster analysis in order to classify the sampled area into geochemical provinces. The contaminated stream under investigation comprised one province and the background streams constituted another province. A linear regression performed on the data showed a statistically significant decrease of several variables with increasing distance from the outlet of the sewage treatment plant. An abrupt decrease in concentration of iron some 450 m below the plant outlet implied the presence of two populations with different means, which was statistically verified with a trimmed t‐test.Use of these simple tests greatly facilitated interpretation of the data.
Chemical Changes in an Industrial Waste Liquid During Post‐Injection Movement in a Limestone Aquifer, Pensacola, Florida
Authors: Ehrlich G. G. , Godsy E. M. , Pascale C. A. , Vecchioli John 
Published: July 2006

ABSTRACTAn industrial waste liquid containing organonitrile compounds and nitrate ion has been injected into the lower limestone of the Floridan aquifer near Pensacola, Florida since June 1975. Chemical analyses of water from monitor wells and backflow from the injection well indicate that organic carbon compounds are converted to CO2 and nitrate is converted to N2. These transformations are caused by bacteria immediately after injection, and are virtually completed within 100 m of the injection well. The zone near the injection well behaves like an anaerobic filter with nitrate respiring bacteria dominating the microbial flora in this zone.Sodium thiocyanate contained in the waste is unaltered during passage through the injection zone and is used to detect the degree of mixing of injected waste liquid with native water at a monitor well 312 m (712 ft) from the injection well. The dispersivity of the injection zone was calculated to be 10 m (33 ft). Analyses of samples from the monitor well indicate 80 percent reduction in chemical oxygen demand and virtually complete loss of organonitriles and nitrate from the waste liquid during passage from the injection well to the monitor well. Bacterial densities were much lower at the monitor well than in backflow from the injection well.
Theis Parameter Evaluation from Pumping Tests by Sensitivity Analysis
Authors: McElwee Carl D. 
Published: July 2006

ABSTRACTThrough the years the Theis equation has played an important role in ground‐water hydrology. Comparison of experimental pumping‐test data with this theoretical curve by graphic means has been a standard method of determining aquifer transmissivity and storage. The purpose of this paper is to present a technique and an algorithm to automatically fit experimental pumping‐test data to the Theis equation by obtaining the “best” transmissivity and storage in the least squares sense through the use of sensitivity analysis. The automated fit for pumping‐test data developed in this work should be a useful tool for the ground‐water hydrologist. Use of the technique is simple, quick, and inexpensive, and has the advantage of always being objective. As a measure of the error in fitting, the rms deviation in drawdown is calculated for the “best” transmissivity and storage.
Programmable Hand Calculator Programs for Pumping and Injection Wells: II — Constant Pumping (Injection) Rate, Single Fully Penetrating Well, Semiconfined Aquifer
Authors: Warner Don L. , Yow M. Gene 
Published: July 2006

ABSTRACTProgrammable calculator programs have been previously given for the calculation of head or pressure change resulting from the pumping from or injection into wells completely penetrating a fully confined aquifer. Programs are documented and example calculations shown here for wells completely penetrating a semiconfined aquifer. The programs are for the TI 59 card programmable calculator.
Aquifer Occurrence in the Fort Payne Formationab
Authors: Moran Mary S. 
Published: July 2006

ABSTRACTThe Fort Payne Formation of Early Mississippian (Osagean) age crops out over extensive areas of central Tennessee, south‐central Kentucky, and northern Alabama. Specific formation lithologies are known to have been modified locally through weathering into an artesian aquifer along the Eastern Highland Rim of central Tennessee. The shallow aquifer can be divided into two parts; uppermost is a highly permeable chert gravel zone that is in hydraulic communication with a lower zone of interconnected solution cavities within bedrock. The gravel, at depths as great as 24.4 m (80 ft), fines upward into the clay‐sized chert of the upper confining bed. The lower confining bed is the Chattanooga Shale of Late Devonian to Early Mississippian age.Field and petrographic studies of the Fort Payne Formation indicate that the aquifer has developed near the base of the unit. The chert gravel portion of the aquifer has developed from silicified dolowackestones of the Beaver Creek Limestone Member and from interbedded Fort Payne dolostones. The lower portion of the aquifer occurs within preferentially weathered, silicified and non‐silicified dolosiltstone.
Ground‐Water Modeling: Mathematical Modelsa
Authors: Mercer James W. , Faust Charles R. 
Published: July 2006

ABSTRACTGround‐water modeling begins with a conceptual understanding of the physical problem. The next step in modeling is translating the physical system into mathematical terms. In general, the final results are the familiar ground‐water flow equation and transport equations. These equations, however, are often simplified, using site‐specific assumptions, to form a variety of equation subsets. An understanding of these equations and their associated boundary and initial conditions is necessary before a modeling problem can be formulated.
Trace‐Organics Biodegradation in Aquifer Recharge
Authors: Rittmann Bruce E. , McCarty Perry L. , Roberts Paul V. 
Published: July 2006

ABSTRACTThe low organic concentration and high specific surface area that characterize ground‐water recharge environments allow biofilms to predominate microbial kinetics. Consideration of the kinetics of substrate utilization and growth of biofilms indicates that microbiological activity occurs very near the injection well. The aggregate substrate expressed, for example, as chemical oxygen demand, can be considered the primary substrate; the biofilm's growth is supported through the utilization of the aggregate primary substrate. Individual trace organic compounds, none of which could support biofilm growth alone, are utilized as secondary substrates. Although biodegradable, secondary substrates that have slow utilization kinetics will pass through the biologically active zone undegraded. Field data from the ground‐water recharge project in Palo Alto, California, illustrate that naphthalene and heptaldehyde are biodegraded, while other compounds, such as chloroform and chlorobenzene, pass through the biologically active zone without biodegradation.
The Role of Ground Water in Stream Discharges from Two Small Wetland Controlled Basins in Eastern Massachusetts
Authors: O'Brien Arnold L. 
Published: July 2006

ABSTRACTGround‐water discharge was found to be the primary cause of flood peaks generated at two small wetland controlled basins in eastern Massachusetts. Within the wetlands, ground water rose rapidly following precipitation and in near synchronization with stream levels indicating a close coupling between ground water and the stream. Stream hydrographs were separated into baseflow and surface runoff by a dynamic technique which matches the hydrograph of an index well with the stream hydrograph to determine the moment of maximum ground‐water discharge. Hydrograph analysis showed that for both wetlands ground water was the major component of all flood peaks and accounted for approximately 93% of the total annual discharge.
Simulation of Salt‐Water Interface Motion
Authors: Mercer James W. , Larson Steven P. , Faust Charles R. 
Published: July 2006

ABSTRACTA numerical model is presented that solves the partial differential equations describing the motion of salt water and fresh water separated by a sharp interface. The areal equations are based on the Dupuit approximation and are obtained from partial integration over the vertical dimension. Finite‐difference techniques are applied and the utility of several solution schemes is tested. The most efficient and accurate solution scheme uses block line‐successive over‐relaxation. Examples are given to: (1) test the model, (2) evaluate the Dupuit approximation, and (3) demonstrate the application to a field situation. The results show that the model is in good agreement with an analytical solution, but under severe conditions the Dupuit approximation may be inappropriate. The model is applied to a field area near Kahului, Maui, Hawaii and results extend the analysis of the problem beyond previous efforts.
A Nitrogen Powered Continuous Delivery, All‐Glass‐Teflon Pumping System for Ground‐Water Sampling from Below 10 Meters
Authors: Tomson M. B. , Hutchinsa Steve , Kingb Joe M. , Warda C. H. 
Published: July 2006

ABSTRACTA nitrogen powered, all‐glass‐Teflon, continuous delivery, noncontaminating pump system is described. Continuous flow rates up to 45 gal‐hr‐1 (2.84 1‐sec‐1) are obtainable. The system was developed and field tested to sample water wells with static heads greater than 32 ft (10 m) for measurements of trace level organics. The system is equally applicable to environments such as marine, lake, and other unconfined water or fluid systems. Also, the analysis can be extended to inorganic and microbial assays in that the sample obtained is unaltered with respect to chemical, physical, and biological properties.
Investigation of Organic Contamination of Ground Water in South Brunswick Township, New Jersey
Authors: Roux Paul H. , Althoff William F. 
Published: July 2006

ABSTRACTAnalyses of several hundred ground‐water samples from over 100 wells, and water table elevations measured in about 60 wells were used to determine the sources, distribution and movement of organohalide contaminants within two unconsolidated aquifers in South Brunswick Township, New Jersey. 1,1,1‐trichloroethane and other organic contaminants were found to have migrated more than 3,000 feet from one source to a public supply well. Lithologic logs from existing wells and monitor wells drilled for the investigation indicate that the Old Bridge aquifer, used for domestic supplies, is underlain by a clay aquitard (Woodbridge clay?) which in turn is underlain by the Farrington sand, a very productive and heavily pumped aquifer used for public supply. Well logs and water elevations were used to define the existence and location of a breach or window in the clay formation. This feature recharges the deeper aquifer and has allowed organic contaminants to reach the Farrington after contaminating wells screened in the upper unit. A large‐capacity well has been contaminated as a result. Water table altitudes were used to show the possible existence of a second breach in the clay layer that may allow organics to reach a second public supply well screened in the lower aquifer within the next few years.
Aquifer Response in the Ultramafic Field Area of Sukhinda Valley — Orissa (India)
Authors: Radhakrishna I. , Venkateswarlu T. 
Published: July 2006

ABSTRACTAnalysis of a long‐duration aquifer performance test utilizing a well near Kansa in the Sukhinda ultramafic body of the Cuttack District in Orissa has demonstrated that nonequilibrium formulae can be applied to hard‐rock regions depending upon the stage of hydrogeological regime and the vertical leakage in the system. Graphical analysis of test results under nonsteady and steady‐state conditions have helped in understanding the behavior of aquifers and their characteristics. A comparative examination of results obtained by different methods and careful insight has helped in delineating the boundary conditions, long‐term withdrawal effects and well spacing problems in the present area, and this approach could be applied in similar well fields.
Ground‐Water Information: NWWA Provides the Resources
Authors: Poland Jean 
Published: July 2006

ABSTRACTAs the volume of hydrogeologic literature increases, researchers are finding it more difficult to identify and locate information. The National Water Well Association's Library/Information Center is a central source of ground‐water information. In addition to collecting books, journals, and reports relevant to ground‐water research, the Library/ Information Center conducts both manual and computer literature searches. A bibliographic data base of hydro‐geologic references is in development.
Hydraulic Properties of Coal and Related Materials, Northern Great Plains
Authors: Rehm Bernd W. , Groenewold Gerald H. , Morin Kevin A. 
Published: July 2006

ABSTRACTThe hydraulic properties (hydraulic conductivity, specific storage and porosity) of coal and the sediments that surround the coal must be known or estimated to properly evaluate the environmental impact of coal strip mining on ground‐water flow systems. Published and unpublished data have been summarized from five study areas in North Dakota, three areas in Wyoming, two areas in Montana and two study sites in Alberta. Coal and sand beds form important aquifers in the region. Both materials have hydraulic conductivities of about 2 × 10−6 m.s−1 and specific storage values on the order of 5 × 10−6 m−1. Aquitards in the region consist of clayey silt to clay bedrock and pebble−loam (in parts of the region). The aquitards are fractured to varying degrees resulting in a wide range of measured hydraulic conductivity values. The aquitards are, in general, 100 to 1,000 times less permeable than the aquifers. Specific storage values of the aquitard material is on the order of 3 × 10−4 m−1. The hydraulic conductivity of strip mine spoils has a six order of magnitude range with a mean of 8 × 10−7 m.s−1. Variability is due to a number of factors including spatial variation of overburden lithology, method of spoil handling and contouring and time of year during which the spoil is handled. The hydraulic conductivity of the coal shows wide spatial variability within a given mine site. Variability of coal hydraulic conductivity between mines within North Dakota is less than within a given mine. Within the Northern Great Plains the permeability of coal may increase slightly from east to west.
The Clogging of Shallow Discharge Wells in the Netherlands River Region
Authors: van Beek C.G.E.M. , Kooper W. F. 
Published: July 2006

ABSTRACTA serious type of clogging occurs in wells which abstract anaerobic water from the shallow aquifer in the river region in The Netherlands. These clogged wells can easily be regenerated by means of sodium hypochlorite (15%). The figure for the specific yield after regeneration approximates to the figure on commissioning.During the pumping to waste to clear the well after regeneration, the types of reaction products present in the spent chlorine solution were investigated. From this it can be deduced that the chlorine solution added was utilised mostly for the oxidation of iron sulphides. The remainder was used mainly for the oxidation of organic material. At the same time, calcium carbonate went into solution and iron carbonate was formed. During the regeneration of a number of wells, some silt was also removed.Although information can be obtained in this way about the composition of the materials removed, it is impossible to form any concept of the nature in which these substances are present around the clogged wells.