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Sample records for ground-water transport model

  1. An assembly model for simulation of large-scale ground water flow and transport.

    Science.gov (United States)

    Huang, Junqi; Christ, John A; Goltz, Mark N

    2008-01-01

    When managing large-scale ground water contamination problems, it is often necessary to model flow and transport using finely discretized domains--for instance (1) to simulate flow and transport near a contamination source area or in the area where a remediation technology is being implemented; (2) to account for small-scale heterogeneities; (3) to represent ground water-surface water interactions; or (4) some combination of these scenarios. A model with a large domain and fine-grid resolution will need extensive computing resources. In this work, a domain decomposition-based assembly model implemented in a parallel computing environment is developed, which will allow efficient simulation of large-scale ground water flow and transport problems using domain-wide grid refinement. The method employs common ground water flow (MODFLOW) and transport (RT3D) simulators, enabling the solution of almost all commonly encountered ground water flow and transport problems. The basic approach partitions a large model domain into any number of subdomains. Parallel processors are used to solve the model equations within each subdomain. Schwarz iteration is applied to match the flow solution at the subdomain boundaries. For the transport model, an extended numerical array is implemented to permit the exchange of dispersive and advective flux information across subdomain boundaries. The model is verified using a conventional single-domain model. Model simulations demonstrate that the proposed model operated in a parallel computing environment can result in considerable savings in computer run times (between 50% and 80%) compared with conventional modeling approaches and may be used to simulate grid discretizations that were formerly intractable.

  2. Reactive chemical transport in ground-water hydrology: Challenges to mathematical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, T.N.; Apps, J.A.

    1990-07-01

    For a long time, earth scientists have qualitatively recognized that mineral assemblages in soils and rocks conform to established principles of chemistry. In the early 1960's geochemists began systematizing this knowledge by developing quantitative thermodynamic models based on equilibrium considerations. These models have since been coupled with advective-dispersive-diffusive transport models, already developed by ground-water hydrologists. Spurred by a need for handling difficult environmental issues related to ground-water contamination, these models are being improved, refined and applied to realistic problems of interest. There is little doubt that these models will play an important role in solving important problems of engineering as well as science over the coming years. Even as these models are being used practically, there is scope for their improvement and many challenges lie ahead. In addition to improving the conceptual basis of the governing equations, much remains to be done to incorporate kinetic processes and biological mediation into extant chemical equilibrium models. Much also remains to be learned about the limits to which model predictability can be reasonably taken. The purpose of this paper is to broadly assess the current status of knowledge in modeling reactive chemical transport and to identify the challenges that lie ahead.

  3. Modelling of the reactive transport of organic pollutants in ground water; Modellierung des reaktiven Transports organischer Schadstoffe im Grundwasser

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, W. [Heidelberg Univ. (Germany). Inst. fuer Umweltphysik

    1999-07-01

    The book describes reactive transport of organic pollutants in ground water and its quantitative monitoring by means of numerical reaction transport models. A brief introduction dealing with the importance of and hazards to ground water and opportunities for making use of ground water models is followed by a more detailed chapter on organic pollutants in ground water. Here the focus is on organochlorine compounds and mineral oil products. Described are propagation mechanisms for these substances in the ground and, especially, their degradability in ground water. A separate chapter is dedicated to possibilities for cleaning up polluted ground water aquifers. The most important decontamination techniques are presented, with special emphasis on in-situ processes with hydraulic components. Moreover, this chapter discusses the self-cleaning capability of aquifers and the benefits of the application of models to ground water cleanup. In the fourth chapter the individual components of reaction transport models are indicated. Here it is, inter alia, differences in the formulation of reaction models as to their complexity, and coupling between suspended matter transport and reaction processes that are dealt with. This chapter ends with a comprehensive survey of literature regarding the application of suspended matter transport models to real ground water accidents. Chapter 5 consists of a description of the capability and principle of function of the reaction transport model TBC (transport biochemism/chemism). This model is used in the two described applications to the reactive transport of organic pollutants in ground water. (orig.) [German] Inhalt des vorliegenden Buches ist die Darstellung des reaktiven Transports organischer Schadstoffe im Grundwasser und dessen quantitative Erfassung mithilfe numerischer Reaktions-Transportmodelle. Auf eine kurze Einleitung zur Bedeutung und Gefaehrdung von Grundwasser und zu den Einsatzmoeglichkeiten von Grundwassermodellen folgt ein

  4. Computer model of two-dimensional solute transport and dispersion in ground water

    Science.gov (United States)

    Konikow, Leonard F.; Bredehoeft, J.D.

    1978-01-01

    This report presents a model that simulates solute transport in flowing ground water. The model is both general and flexible in that it can be applied to a wide range of problem types. It is applicable to one- or two-dimensional problems involving steady-state or transient flow. The model computes changes in concentration over time caused by the processes of convective transport, hydrodynamic dispersion, and mixing (or dilution) from fluid sources. The model assumes that the solute is non-reactive and that gradients of fluid density, viscosity, and temperature do not affect the velocity distribution. However, the aquifer may be heterogeneous and (or) anisotropic. The model couples the ground-water flow equation with the solute-transport equation. The digital computer program uses an alternating-direction implicit procedure to solve a finite-difference approximation to the ground-water flow equation, and it uses the method of characteristics to solve the solute-transport equation. The latter uses a particle- tracking procedure to represent convective transport and a two-step explicit procedure to solve a finite-difference equation that describes the effects of hydrodynamic dispersion, fluid sources and sinks, and divergence of velocity. This explicit procedure has several stability criteria, but the consequent time-step limitations are automatically determined by the program. The report includes a listing of the computer program, which is written in FORTRAN IV and contains about 2,000 lines. The model is based on a rectangular, block-centered, finite difference grid. It allows the specification of any number of injection or withdrawal wells and of spatially varying diffuse recharge or discharge, saturated thickness, transmissivity, boundary conditions, and initial heads and concentrations. The program also permits the designation of up to five nodes as observation points, for which a summary table of head and concentration versus time is printed at the end of the

  5. Digital-transport model study of Diisopropylmethylphosphonate (DIMP) ground-water contamination at the Rocky Mountain Arsenal, Colorado

    Science.gov (United States)

    Warner, James W.

    1979-01-01

    Diisopropylmethylphosphonate (DIMP) is an organic compound produced as a by-product of the manufacture and detoxification of GB nerve gas. Ground-water contamination by DIMP from the disposal of wastes into unlined surface ponds at the Rocky Mountain Arsenal occurred from 1952 to 1956. A digital-transport model was used to determine the effects on ground-water movement and on DIMP concentrations in the ground water of a bentonite barrier in the aquifer near the northern boundary of the arsenal. The transport model is based on an iterative-alternating-direction-implicit mathematical solution of the ground-water-flow equation coupled with a method-of-characteristics solution of the solute-transport equation. The model assumes conservative (nonreactive) transient transport of DIMP and steady-state ground-water flow. In the model simulations, a bentonite barrier was assumed that was impermeable and penetrated the entire saturated thickness of the aquifer. Ground water intercepted by the barrier was assumed to be pumped by wells located south (upgradient) of the barrier, to be treated to remove DIMP, and to be recharged by pits or wells to the aquifer north (downgradient) of the barrier. The amount of DIMP transported across the northern boundary of the arsenal was substantially reduced by a ground-water-barrier system of this type. For a 1,500-foot-long bentonite barrier located along the northern boundary of the arsenal near D Street, about 50 percent of the DIMP that would otherwise cross the boundary would be intercepted by the barrier. This barrier configuration and location were proposed by the U.S. Army. Of the ground water with DIMP concentrations greater than 500 micrograms per liter, the safe DIMP-concentration level determined by the U.S. Army, about 72 percent would be intercepted by the barrier system. The amount of DIMP underflow intercepted may be increased to 65 percent by doubling the pumpage, or to 73 percent by doubling the length of the barrier

  6. Modeled ground water age distributions

    Science.gov (United States)

    Woolfenden, Linda R.; Ginn, Timothy R.

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  7. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-05-01

    This document was written to provide guidance to managers and site operators on how ground-water transport codes should be selected for assessing burial site performance. There is a need for a formal approach to selecting appropriate codes from the multitude of potentially useful ground-water transport codes that are currently available. Code selection is a problem that requires more than merely considering mathematical equation-solving methods. These guidelines are very general and flexible and are also meant for developing systems simulation models to be used to assess the environmental safety of low-level waste burial facilities. Code selection is only a single aspect of the overall objective of developing a systems simulation model for a burial site. The guidance given here is mainly directed toward applications-oriented users, but managers and site operators need to be familiar with this information to direct the development of scientifically credible and defensible transport assessment models. Some specific advice for managers and site operators on how to direct a modeling exercise is based on the following five steps: identify specific questions and study objectives; establish costs and schedules for achieving answers; enlist the aid of professional model applications group; decide on approach with applications group and guide code selection; and facilitate the availability of site-specific data. These five steps for managers/site operators are discussed in detail following an explanation of the nine systems model development steps, which are presented first to clarify what code selection entails.

  8. Numerical modeling of ground water flow and contaminant transport in a saturated porous medium

    Science.gov (United States)

    Valipour, Mohammad S.; Sadeghi, Masoomeh; Mahmoudi, Amir H.; Shahi, Mina; Gandaghi, Hadi

    2012-05-01

    In this paper, numerical modeling and experimental testing of the distribution of pollutants along the water flow in a porous medium is discussed. Governing equations including overall continuity, momentum and species continuity equations are derived for porous medium. The governing equations have been solved numerical using the Finite Volume Method based on collocated grids. The SIMPLE algorithm has been adopted for the pressure _ velocity linked equations. In order to validate the numerical results, experimental data from laboratory apparatus are applied and there is a good agreement among numerical results and experimental test. Finally, the main affecting parameters on the distribution and transport of pollutants porous medium were investigated. Results indicate that, the domain of pollution rises with increasing dispersion coefficient and the dispersion phenomenon overcomes on pollutant transfer. Reduction of porosity has decreased the pollutant transfer and increased velocity has result in the increasing pollutant transport phenomenon but has reduced the domain of the pollution.

  9. Recharge estimation for transient ground water modeling.

    Science.gov (United States)

    Jyrkama, Mikko I; Sykes, Jon F; Normani, Stefano D

    2002-01-01

    Reliable ground water models require both an accurate physical representation of the system and appropriate boundary conditions. While physical attributes are generally considered static, boundary conditions, such as ground water recharge rates, can be highly variable in both space and time. A practical methodology incorporating the hydrologic model HELP3 in conjunction with a geographic information system was developed to generate a physically based and highly detailed recharge boundary condition for ground water modeling. The approach uses daily precipitation and temperature records in addition to land use/land cover and soils data. The importance of the method in transient ground water modeling is demonstrated by applying it to a MODFLOW modeling study in New Jersey. In addition to improved model calibration, the results from the study clearly indicate the importance of using a physically based and highly detailed recharge boundary condition in ground water quality modeling, where the detailed knowledge of the evolution of the ground water flowpaths is imperative. The simulated water table is within 0.5 m of the observed values using the method, while the water levels can differ by as much as 2 m using uniform recharge conditions. The results also show that the combination of temperature and precipitation plays an important role in the amount and timing of recharge in cooler climates. A sensitivity analysis further reveals that increasing the leaf area index, the evaporative zone depth, or the curve number in the model will result in decreased recharge rates over time, with the curve number having the greatest impact.

  10. SUTRA: A model for 2D or 3D saturated-unsaturated, variable-density ground-water flow with solute or energy transport

    Science.gov (United States)

    Voss, Clifford I.; Provost, A.M.

    2002-01-01

    SUTRA (Saturated-Unsaturated Transport) is a computer program that simulates fluid movement and the transport of either energy or dissolved substances in a subsurface environment. This upgraded version of SUTRA adds the capability for three-dimensional simulation to the former code (Voss, 1984), which allowed only two-dimensional simulation. The code employs a two- or three-dimensional finite-element and finite-difference method to approximate the governing equations that describe the two interdependent processes that are simulated: 1) fluid density-dependent saturated or unsaturated ground-water flow; and 2) either (a) transport of a solute in the ground water, in which the solute may be subject to: equilibrium adsorption on the porous matrix, and both first-order and zero-order production or decay; or (b) transport of thermal energy in the ground water and solid matrix of the aquifer. SUTRA may also be used to simulate simpler subsets of the above processes. A flow-direction-dependent dispersion process for anisotropic media is also provided by the code and is introduced in this report. As the primary calculated result, SUTRA provides fluid pressures and either solute concentrations or temperatures, as they vary with time, everywhere in the simulated subsurface system. SUTRA flow simulation may be employed for two-dimensional (2D) areal, cross sectional and three-dimensional (3D) modeling of saturated ground-water flow systems, and for cross sectional and 3D modeling of unsaturated zone flow. Solute-transport simulation using SUTRA may be employed to model natural or man-induced chemical-species transport including processes of solute sorption, production, and decay. For example, it may be applied to analyze ground-water contaminant transport problems and aquifer restoration designs. In addition, solute-transport simulation with SUTRA may be used for modeling of variable-density leachate movement, and for cross sectional modeling of saltwater intrusion in

  11. Ground-water models: Validate or invalidate

    Science.gov (United States)

    Bredehoeft, J.D.; Konikow, L.F.

    1993-01-01

    The word validation has a clear meaning to both the scientific community and the general public. Within the scientific community the validation of scientific theory has been the subject of philosophical debate. The philosopher of science, Karl Popper, argued that scientific theory cannot be validated, only invalidated. Popper’s view is not the only opinion in this debate; however, many scientists today agree with Popper (including the authors). To the general public, proclaiming that a ground-water model is validated carries with it an aura of correctness that we do not believe many of us who model would claim. We can place all the caveats we wish, but the public has its own understanding of what the word implies. Using the word valid with respect to models misleads the public; verification carries with it similar connotations as far as the public is concerned. Our point is this: using the terms validation and verification are misleading, at best. These terms should be abandoned by the ground-water community.

  12. CHEMICAL REACTIONS SIMULATED BY GROUND-WATER-QUALITY MODELS.

    Science.gov (United States)

    Grove, David B.; Stollenwerk, Kenneth G.

    1987-01-01

    Recent literature concerning the modeling of chemical reactions during transport in ground water is examined with emphasis on sorption reactions. The theory of transport and reactions in porous media has been well documented. Numerous equations have been developed from this theory, to provide both continuous and sequential or multistep models, with the water phase considered for both mobile and immobile phases. Chemical reactions can be either equilibrium or non-equilibrium, and can be quantified in linear or non-linear mathematical forms. Non-equilibrium reactions can be separated into kinetic and diffusional rate-limiting mechanisms. Solutions to the equations are available by either analytical expressions or numerical techniques. Saturated and unsaturated batch, column, and field studies are discussed with one-dimensional, laboratory-column experiments predominating. A summary table is presented that references the various kinds of models studied and their applications in predicting chemical concentrations in ground waters.

  13. Ground water flow in a desert basin: challenges of simulating transport of dissolved chromium.

    Science.gov (United States)

    Andrews, Charles B; Neville, Christopher J

    2003-01-01

    A large chromium plume that evolved from chromium releases in a valley near the Mojave River was studied to understand the processes controlling fate and migration of chromium in ground water and used as a tracer to study the dynamics of a basin and range ground water system. The valley that was studied is naturally arid with high evapotranspiration such that essentially no precipitation infiltrates to the water table. The dominant natural hydrogeologic processes are recharge to the ground water system from the Mojave River during the infrequent episodes when there is flow in the river, and ground water flow toward a playa lake where the ground water evaporates. Agricultural pumping in the valley from the mid-1930s to the 1970s significantly altered ground water flow conditions by decreasing water levels in the valley by more than 20 m. This pumping declined significantly as a result of dewatering of the aquifer, and water levels have since recovered modestly. The ground water system was modeled using MODFLOW, and chromium transport was simulated using MT3D. Several innovative modifications were made to these modeling programs to simulate important processes in this ground water system. Modifications to MODFLOW include developing a new well package that estimates pumping rates from irrigation wells at each time step based on available drawdown. MT3D was modified to account for mass trapped above the water table when the water table declines beneath nonirrigated areas and to redistribute mass to the system when water levels rise.

  14. User interface for ground-water modeling: Arcview extension

    Science.gov (United States)

    Tsou, M.-S.; Whittemore, D.O.

    2001-01-01

    Numerical simulation for ground-water modeling often involves handling large input and output data sets. A geographic information system (GIS) provides an integrated platform to manage, analyze, and display disparate data and can greatly facilitate modeling efforts in data compilation, model calibration, and display of model parameters and results. Furthermore, GIS can be used to generate information for decision making through spatial overlay and processing of model results. Arc View is the most widely used Windows-based GIS software that provides a robust user-friendly interface to facilitate data handling and display. An extension is an add-on program to Arc View that provides additional specialized functions. An Arc View interface for the ground-water flow and transport models MODFLOW and MT3D was built as an extension for facilitating modeling. The extension includes preprocessing of spatially distributed (point, line, and polygon) data for model input and postprocessing of model output. An object database is used for linking user dialogs and model input files. The Arc View interface utilizes the capabilities of the 3D Analyst extension. Models can be automatically calibrated through the Arc View interface by external linking to such programs as PEST. The efficient pre- and postprocessing capabilities and calibration link were demonstrated for ground-water modeling in southwest Kansas.

  15. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Volume 2. Special test cases

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-08-01

    This document was written for the National Low-Level Waste Management Program to provide guidance for managers and site operators who need to select ground-water transport codes for assessing shallow-land burial site performance. The guidance given in this report also serves the needs of applications-oriented users who work under the direction of a manager or site operator. The guidelines are published in two volumes designed to support the needs of users having different technical backgrounds. An executive summary, published separately, gives managers and site operators an overview of the main guideline report. Volume 1, titled ''Guideline Approach,'' consists of Chapters 1 through 5 and a glossary. Chapters 2 through 5 provide the more detailed discussions about the code selection approach. This volume, Volume 2, consists of four appendices reporting on the technical evaluation test cases designed to help verify the accuracy of ground-water transport codes. 20 refs.

  16. Use of a ground-water flow model with particle tracking to evaluate ground-water vulnerability, Clark County, Washington

    Science.gov (United States)

    Snyder, D.T.; Wilkinson, J.M.; Orzol, L.L.

    1996-01-01

    public-supply wells in Clark County may be receiving a component of water that recharged in areas that are more conducive to contaminant entry. The aquifer sensitivity maps illustrate a critical deficiency in the DRASTIC methodology: the failure to account for the dynamics of the ground-water flow system. DRASTIC indices calculated for a particular location thus do not necessarily reflect the conditions of the ground-water resources at the recharge areas to that particular location. Each hydrogeologic unit was also mapped to highlight those areas that will eventually receive flow from recharge areas with on-site waste-disposal systems. Most public-supply wells in southern Clark County may eventually receive a component of water that was recharged from on-site waste-disposal systems.Traveltimes from particle tracking were used to estimate the minimum and maximum age of ground water within each model-grid cell. Chlorofluorocarbon (CFC)-age dating of ground water from 51 wells was used to calibrate effective porosity values used for the particle- tracking program by comparison of ground-water ages determined through the use of the CFC-age dating with those calculated by the particle- tracking program. There was a 76 percent agreement in predicting the presence of modern water in the 51 wells as determined using CFCs and calculated by the particle-tracking program. Maps showing the age of ground water were prepared for all the hydrogeologic units. Areas with the youngest ground-water ages are expected to be at greatest risk for contamination from anthropogenic sources. Comparison of these maps with maps of public- supply wells in Clark County indicates that most of these wells may withdraw ground water that is, in part, less than 100 years old, and in many instances less than 10 years old. Results of the analysis showed that a single particle-tracking analysis simulating advective transport can be used to evaluate ground-water vulnerability for any part of a ground-wate

  17. Documentation of a computer program to simulate lake-aquifer interaction using the MODFLOW ground water flow model and the MOC3D solute-transport model

    Science.gov (United States)

    Merritt, Michael L.; Konikow, Leonard F.

    2000-01-01

    Heads and flow patterns in surficial aquifers can be strongly influenced by the presence of stationary surface-water bodies (lakes) that are in direct contact, vertically and laterally, with the aquifer. Conversely, lake stages can be significantly affected by the volume of water that seeps through the lakebed that separates the lake from the aquifer. For these reasons, a set of computer subroutines called the Lake Package (LAK3) was developed to represent lake/aquifer interaction in numerical simulations using the U.S. Geological Survey three-dimensional, finite-difference, modular ground-water flow model MODFLOW and the U.S. Geological Survey three-dimensional method-of-characteristics solute-transport model MOC3D. In the Lake Package described in this report, a lake is represented as a volume of space within the model grid which consists of inactive cells extending downward from the upper surface of the grid. Active model grid cells bordering this space, representing the adjacent aquifer, exchange water with the lake at a rate determined by the relative heads and by conductances that are based on grid cell dimensions, hydraulic conductivities of the aquifer material, and user-specified leakance distributions that represent the resistance to flow through the material of the lakebed. Parts of the lake may become ?dry? as upper layers of the model are dewatered, with a concomitant reduction in lake surface area, and may subsequently rewet when aquifer heads rise. An empirical approximation has been encoded to simulate the rewetting of a lake that becomes completely dry. The variations of lake stages are determined by independent water budgets computed for each lake in the model grid. This lake budget process makes the package a simulator of the response of lake stage to hydraulic stresses applied to the aquifer. Implementation of a lake water budget requires input of parameters including those representing the rate of lake atmospheric recharge and evaporation

  18. Potential risk of microplastics transportation into ground water

    Science.gov (United States)

    Huerta, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A.; Geissen, Violette

    2016-04-01

    Microplastics, are plastics particles with a size smaller than 5mm. They are formed by the fragmentation of plastic wastes. They are present in the air, soil and water. But only in aquatic systems (ocean and rivers) are studies over their distribution, and the effect of microplastics on organisms. There is a lack of information of what is the distribution of microplastics in the soil, and in the ground water. This study tries to estimate the potential risk of microplastics transportation into the ground water by the activity of earthworms. Earthworms can produce burrows and/or galleries inside the soil, with the presence of earthworms some ecosystem services are enhanced, as infiltration. In this study we observed after 14 days with 5 treatments (0, 7, 28 and 60% w/w microplastics mixed with Populus nigra litter) and the anecic earthworm Lumbricus terrestris, in microcosms (3 replicas per treatment) that macroplastics are indeed deposit inside earthworms burrows, with 7% microplastics on the surface is possible to find 1.8 g.kg-1 microplastics inside the burrows, with a bioaumentation factor of 0.65. Burrows made by earthworms under 60% microplastics, are significant bigger (pmicroplastics in their soil surface. The amount of litter that is deposit inside the burrows is significant higher (pmicroplastics on the surface than without microplastics. The microplastics size distribution is smaller inside the burrows than on the surface, with an abundance of particles under 63 μm.

  19. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Volume 1. Guideline approach

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-05-01

    This document was written for the National Low-Level Waste Management Program to provide guidance for managers and site operators who need to select ground-water transport codes for assessing shallow-land burial site performance. The guidance given in this report also serves the needs of applications-oriented users who work under the direction of a manager or site operator. The guidelines are published in two volumes designed to support the needs of users having different technical backgrounds. An executive summary, published separately, gives managers and site operators an overview of the main guideline report. This volume includes specific recommendations for decision-making managers and site operators on how to use these guidelines. The more detailed discussions about the code selection approach are provided. 242 refs., 6 figs.

  20. Death Valley regional ground-water flow system, Nevada and California -- hydrogeologic framework and transient ground-water flow model

    Science.gov (United States)

    : Belcher, Wayne R.

    2004-01-01

    A numerical three-dimensional (3D) transient ground-water flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Energy programs at the Nevada Test Site and at Yucca Mountain, Nevada. Decades of study of aspects of the ground-water flow system and previous less extensive ground-water flow models were incorporated and reevaluated together with new data to provide greater detail for the complex, digital model. A 3D digital hydrogeologic framework model (HFM) was developed from digital elevation models, geologic maps, borehole information, geologic and hydrogeologic cross sections, and other 3D models to represent the geometry of the hydrogeologic units (HGUs). Structural features, such as faults and fractures, that affect ground-water flow also were added. The HFM represents Precambrian and Paleozoic crystalline and sedimentary rocks, Mesozoic sedimentary rocks, Mesozoic to Cenozoic intrusive rocks, Cenozoic volcanic tuffs and lavas, and late Cenozoic sedimentary deposits of the Death Valley Regional Ground-Water Flow System (DVRFS) region in 27 HGUs. Information from a series of investigations was compiled to conceptualize and quantify hydrologic components of the ground-water flow system within the DVRFS model domain and to provide hydraulic-property and head-observation data used in the calibration of the transient-flow model. These studies reevaluated natural ground-water discharge occurring through evapotranspiration and spring flow; the history of ground-water pumping from 1913 through 1998; ground-water recharge simulated as net infiltration; model boundary inflows and outflows based on regional hydraulic gradients and water budgets of surrounding areas; hydraulic conductivity and its relation to depth; and water levels appropriate for regional simulation of prepumped and pumped conditions within the DVRFS model domain. Simulation results appropriate for the regional extent and scale of the model were

  1. Reduction of large-scale numerical ground water flow models

    NARCIS (Netherlands)

    Vermeulen, P.T.M.; Heemink, A.W.; Testroet, C.B.M.

    2002-01-01

    Numerical models are often used for simulating ground water flow. Written in state space form, the dimension of these models is of the order of the number of model cells and can be very high (> million). As a result, these models are computationally very demanding, especially if many different scena

  2. The role of hand calculations in ground water flow modeling.

    Science.gov (United States)

    Haitjema, Henk

    2006-01-01

    Most ground water modeling courses focus on the use of computer models and pay little or no attention to traditional analytic solutions to ground water flow problems. This shift in education seems logical. Why waste time to learn about the method of images, or why study analytic solutions to one-dimensional or radial flow problems? Computer models solve much more realistic problems and offer sophisticated graphical output, such as contour plots of potentiometric levels and ground water path lines. However, analytic solutions to elementary ground water flow problems do have something to offer over computer models: insight. For instance, an analytic one-dimensional or radial flow solution, in terms of a mathematical expression, may reveal which parameters affect the success of calibrating a computer model and what to expect when changing parameter values. Similarly, solutions for periodic forcing of one-dimensional or radial flow systems have resulted in a simple decision criterion to assess whether or not transient flow modeling is needed. Basic water balance calculations may offer a useful check on computer-generated capture zones for wellhead protection or aquifer remediation. An easily calculated "characteristic leakage length" provides critical insight into surface water and ground water interactions and flow in multi-aquifer systems. The list goes on. Familiarity with elementary analytic solutions and the capability of performing some simple hand calculations can promote appropriate (computer) modeling techniques, avoids unnecessary complexity, improves reliability, and is likely to save time and money. Training in basic hand calculations should be an important part of the curriculum of ground water modeling courses.

  3. Regression modeling of ground-water flow

    Science.gov (United States)

    Cooley, R.L.; Naff, R.L.

    1985-01-01

    Nonlinear multiple regression methods are developed to model and analyze groundwater flow systems. Complete descriptions of regression methodology as applied to groundwater flow models allow scientists and engineers engaged in flow modeling to apply the methods to a wide range of problems. Organization of the text proceeds from an introduction that discusses the general topic of groundwater flow modeling, to a review of basic statistics necessary to properly apply regression techniques, and then to the main topic: exposition and use of linear and nonlinear regression to model groundwater flow. Statistical procedures are given to analyze and use the regression models. A number of exercises and answers are included to exercise the student on nearly all the methods that are presented for modeling and statistical analysis. Three computer programs implement the more complex methods. These three are a general two-dimensional, steady-state regression model for flow in an anisotropic, heterogeneous porous medium, a program to calculate a measure of model nonlinearity with respect to the regression parameters, and a program to analyze model errors in computed dependent variables such as hydraulic head. (USGS)

  4. Model grid and infiltration values for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the model grid and infiltration values simulated in the transient ground-water flow model of the Death Valley regional ground-water...

  5. Model grid and infiltration values for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the model grid and infiltration values simulated in the transient ground-water flow model of the Death Valley regional ground-water...

  6. MODFLOW-2000, the U.S. Geological Survey modular ground-water model : user guide to the LMT6 package, the linkage with MT3DMS for multi-species mass transport modeling

    Science.gov (United States)

    Zheng, Chunmiao; Hill, Mary Catherine; Hsieh, Paul A.

    2001-01-01

    MODFLOW-2000, the newest version of MODFLOW, is a computer program that numerically solves the three-dimensional ground-water flow equation for a porous medium using a finite-difference method. MT3DMS, the successor to MT3D, is a computer program for modeling multi-species solute transport in three-dimensional ground-water systems using multiple solution techniques, including the finite-difference method, the method of characteristics (MOC), and the total-variation-diminishing (TVD) method. This report documents a new version of the Link-MT3DMS Package, which enables MODFLOW-2000 to produce the information needed by MT3DMS, and also discusses new visualization software for MT3DMS. Unlike the Link-MT3D Packages that coordinated previous versions of MODFLOW and MT3D, the new Link-MT3DMS Package requires an input file that, among other things, provides enhanced support for additional MODFLOW sink/source packages and allows list-directed (free) format for the flow model produced flow-transport link file. The report contains four parts: (a) documentation of the Link-MT3DMS Package Version 6 for MODFLOW-2000; (b) discussion of several issues related to simulation setup and input data preparation for running MT3DMS with MODFLOW-2000; (c) description of two test example problems, with comparison to results obtained using another MODFLOW-based transport program; and (d) overview of post-simulation visualization and animation using the U.S. Geological Survey?s Model Viewer.

  7. Determining extreme parameter correlation in ground water models

    DEFF Research Database (Denmark)

    Hill, Mary Cole; Østerby, Ole

    2003-01-01

    In ground water flow system models with hydraulic-head observations but without significant imposed or observed flows, extreme parameter correlation generally exists. As a result, hydraulic conductivity and recharge parameters cannot be uniquely estimated. In complicated problems, such correlation...... correlation coefficients, but it required sensitivities that were one to two significant digits less accurate than those that required using parameter correlation coefficients; and (3) both the SVD and parameter correlation coefficients identified extremely correlated parameters better when the parameters...

  8. An assessment of aquifer storage recovery using ground water flow models.

    Science.gov (United States)

    Lowry, Christopher S; Anderson, Mary P

    2006-01-01

    Owing to increased demands on ground water accompanied by increased drawdowns, technologies that use recharge options, such as aquifer storage recovery (ASR), are being used to optimize available water resources and reduce adverse effects of pumping. In this paper, three representative ground water flow models were created to assess the impact of hydrogeologic and operational parameters/factors on recovery efficiency of ASR systems. Flow/particle tracking and solute transport models were used to track the movement of water during injection, storage, and recovery. Results from particle tracking models consistently produced higher recovery efficiency than the solute transport models for the parameters/properties examined because the particle tracking models neglected mixing of the injected and ambient water. Mixing between injected and ambient water affected recovery efficiency. Results from this study demonstrate the interactions between hydrogeologic and operational parameters on predictions of recovery efficiency. These interactions are best simulated using coupled numerical ground water flow and transport models that include the effects of mixing of injected water and ambient ground water.

  9. Discharge areas for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents discharge areas in the Death Valley regional ground-water flow system (DVRFS) transient model. Natural ground-water discharge occurs...

  10. Boundary of the ground-water flow model by IT Corporation (1996), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the steady-state ground-water flow model built by IT Corporation (1996). The regional, 20-layer ground-water flow...

  11. Discharge areas for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents discharge areas in the Death Valley regional ground-water flow system (DVRFS) transient model. Natural ground-water discharge...

  12. A Guide for Using the Transient Ground-Water Flow Model of the Death Valley Regional Ground-Water Flow System, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    Joan B. Blainey; Claudia C. Faunt, and Mary C. Hill

    2006-05-16

    This report is a guide for executing numerical simulations with the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California using the U.S. Geological Survey modular finite-difference ground-water flow model, MODFLOW-2000. Model inputs, including observations of hydraulic head, discharge, and boundary flows, are summarized. Modification of the DVRFS transient ground-water model is discussed for two common uses of the Death Valley regional ground-water flow system model: predictive pumping scenarios that extend beyond the end of the model simulation period (1998), and model simulations with only steady-state conditions.

  13. PHAST--a program for simulating ground-water flow, solute transport, and multicomponent geochemical reactions

    Science.gov (United States)

    Parkhurst, David L.; Kipp, Kenneth L.; Engesgaard, Peter; Charlton, Scott R.

    2004-01-01

    The computer program PHAST simulates multi-component, reactive solute transport in three-dimensional saturated ground-water flow systems. PHAST is a versatile ground-water flow and solute-transport simulator with capabilities to model a wide range of equilibrium and kinetic geochemical reactions. The flow and transport calculations are based on a modified version of HST3D that is restricted to constant fluid density and constant temperature. The geochemical reactions are simulated with the geochemical model PHREEQC, which is embedded in PHAST. PHAST is applicable to the study of natural and contaminated ground-water systems at a variety of scales ranging from laboratory experiments to local and regional field scales. PHAST can be used in studies of migration of nutrients, inorganic and organic contaminants, and radionuclides; in projects such as aquifer storage and recovery or engineered remediation; and in investigations of the natural rock-water interactions in aquifers. PHAST is not appropriate for unsaturated-zone flow, multiphase flow, density-dependent flow, or waters with high ionic strengths. A variety of boundary conditions are available in PHAST to simulate flow and transport, including specified-head, flux, and leaky conditions, as well as the special cases of rivers and wells. Chemical reactions in PHAST include (1) homogeneous equilibria using an ion-association thermodynamic model; (2) heterogeneous equilibria between the aqueous solution and minerals, gases, surface complexation sites, ion exchange sites, and solid solutions; and (3) kinetic reactions with rates that are a function of solution composition. The aqueous model (elements, chemical reactions, and equilibrium constants), minerals, gases, exchangers, surfaces, and rate expressions may be defined or modified by the user. A number of options are available to save results of simulations to output files. The data may be saved in three formats: a format suitable for viewing with a text editor; a

  14. Pumpage for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents ground-water discharged from the Death Valley regional ground-water flow system (DVRFS) through pumped wells. Pumping from wells in...

  15. A regression model to estimate regional ground water recharge.

    Science.gov (United States)

    Lorenz, David L; Delin, Geoffrey N

    2007-01-01

    A regional regression model was developed to estimate the spatial distribution of ground water recharge in subhumid regions. The regional regression recharge (RRR) model was based on a regression of basin-wide estimates of recharge from surface water drainage basins, precipitation, growing degree days (GDD), and average basin specific yield (SY). Decadal average recharge, precipitation, and GDD were used in the RRR model. The RRR estimates were derived from analysis of stream base flow using a computer program that was based on the Rorabaugh method. As expected, there was a strong correlation between recharge and precipitation. The model was applied to statewide data in Minnesota. Where precipitation was least in the western and northwestern parts of the state (50 to 65 cm/year), recharge computed by the RRR model also was lowest (0 to 5 cm/year). A strong correlation also exists between recharge and SY. SY was least in areas where glacial lake clay occurs, primarily in the northwest part of the state; recharge estimates in these areas were in the 0- to 5-cm/year range. In sand-plain areas where SY is greatest, recharge estimates were in the 15- to 29-cm/year range on the basis of the RRR model. Recharge estimates that were based on the RRR model compared favorably with estimates made on the basis of other methods. The RRR model can be applied in other subhumid regions where region wide data sets of precipitation, streamflow, GDD, and soils data are available.

  16. Boundary of the ground-water flow model by IT Corporation (1996), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the steady-state ground-water flow model built by IT Corporation (1996). The regional, 20-layer ground-water flow model...

  17. GWM-a ground-water management process for the U.S. Geological Survey modular ground-water model (MODFLOW-2000)

    Science.gov (United States)

    Ahlfeld, David P.; Barlow, Paul M.; Mulligan, Anne E.

    2005-01-01

    GWM is a Ground?Water Management Process for the U.S. Geological Survey modular three?dimensional ground?water model, MODFLOW?2000. GWM uses a response?matrix approach to solve several types of linear, nonlinear, and mixed?binary linear ground?water management formulations. Each management formulation consists of a set of decision variables, an objective function, and a set of constraints. Three types of decision variables are supported by GWM: flow?rate decision variables, which are withdrawal or injection rates at well sites; external decision variables, which are sources or sinks of water that are external to the flow model and do not directly affect the state variables of the simulated ground?water system (heads, streamflows, and so forth); and binary variables, which have values of 0 or 1 and are used to define the status of flow?rate or external decision variables. Flow?rate decision variables can represent wells that extend over one or more model cells and be active during one or more model stress periods; external variables also can be active during one or more stress periods. A single objective function is supported by GWM, which can be specified to either minimize or maximize the weighted sum of the three types of decision variables. Four types of constraints can be specified in a GWM formulation: upper and lower bounds on the flow?rate and external decision variables; linear summations of the three types of decision variables; hydraulic?head based constraints, including drawdowns, head differences, and head gradients; and streamflow and streamflow?depletion constraints. The Response Matrix Solution (RMS) Package of GWM uses the Ground?Water Flow Process of MODFLOW to calculate the change in head at each constraint location that results from a perturbation of a flow?rate variable; these changes are used to calculate the response coefficients. For linear management formulations, the resulting matrix of response coefficients is then combined with other

  18. 75 FR 8412 - Office of New Reactors: Interim Staff Guidance on Assessing Ground Water Flow and Transport of...

    Science.gov (United States)

    2010-02-24

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Office of New Reactors: Interim Staff Guidance on Assessing Ground Water Flow and Transport of... Sections 2.4.12 and 2.4.13 regarding the assessment of ground water flow and transport of...

  19. Altitudes of the top of model layers for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the altitudes of the tops of 16 model layers simulated in the Death Valley regional ground-water flow system (DVRFS) transient flow...

  20. Probabilistic Modeling for Risk Assessment of California Ground Water Contamination by Pesticides

    Science.gov (United States)

    Clayton, M.; Troiano, J.; Spurlock, F.

    2007-12-01

    The California Department of Pesticide Regulation (DPR) is responsible for the registration of pesticides in California. DPR's Environmental Monitoring Branch evaluates the potential for pesticide active ingredients to move to ground water under legal agricultural use conditions. Previous evaluations were primarily based on threshold values for specific persistence and mobility properties of pesticides as prescribed in the California Pesticide Contamination Prevention Act of 1985. Two limitations identified with that process were the univariate nature where interactions of the properties were not accounted for, and the inability to accommodate multiple values of a physical-chemical property. We addressed these limitations by developing a probabilistic modeling method based on prediction of potential well water concentrations. A mechanistic pesticide transport model, LEACHM, is used to simulate sorption, degradation and transport of a candidate pesticide through the root zone. A second empirical model component then simulates pesticide degradation and transport through the vadose zone to a receiving ground water aquifer. Finally, degradation during transport in the aquifer to the well screen is included in calculating final potential well concentrations. Using Monte Carlo techniques, numerous LEACHM simulations are conducted using random samples of the organic carbon normalized soil adsorption coefficients (Koc) and soil dissipation half-life values derived from terrestrial field dissipation (TFD) studies. Koc and TFD values are obtained from gamma distributions fitted to pooled data from agricultural-use pesticides detected in California ground water: atrazine, simazine, diuron, bromacil, hexazinone, and norflurazon. The distribution of predicted well water concentrations for these pesticides is in good agreement with concentrations measured in domestic wells in coarse, leaching vulnerable soils of Fresno and Tulure Counties. The leaching potential of a new

  1. Lateral boundary of the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the lateral boundary and model domain of the area simulated by the transient ground-water flow model of the Death Valley regional...

  2. Lateral boundary of the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the lateral boundary and model domain of the area simulated by the transient ground-water flow model of the Death Valley regional...

  3. MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model--Documentation of the SEAWAT-2000 Version with the Variable-Density Flow Process (VDF) and the Integrated MT3DMS Transport Process (IMT)

    Science.gov (United States)

    Langevin, Christian D.; Shoemaker, W. Barclay; Guo, Weixing

    2003-01-01

    SEAWAT-2000 is the latest release of the SEAWAT computer program for simulation of three-dimensional, variable-density, transient ground-water flow in porous media. SEAWAT-2000 was designed by combining a modified version of MODFLOW-2000 and MT3DMS into a single computer program. The code was developed using the MODFLOW-2000 concept of a process, which is defined as ?part of the code that solves a fundamental equation by a specified numerical method.? SEAWAT-2000 contains all of the processes distributed with MODFLOW-2000 and also includes the Variable-Density Flow Process (as an alternative to the constant-density Ground-Water Flow Process) and the Integrated MT3DMS Transport Process. Processes may be active or inactive, depending on simulation objectives; however, not all processes are compatible. For example, the Sensitivity and Parameter Estimation Processes are not compatible with the Variable-Density Flow and Integrated MT3DMS Transport Processes. The SEAWAT-2000 computer code was tested with the common variable-density benchmark problems and also with problems representing evaporation from a salt lake and rotation of immiscible fluids.

  4. Initial hydraulic heads for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the hydraulic-head values in 16 model layers used to initiate the transient simulation of the Death Valley regional ground-water flow...

  5. Transport and fate of nitrate at the ground-water/surface-water interface

    Science.gov (United States)

    Puckett, L.J.; Zamora, C.; Essaid, H.; Wilson, J.T.; Johnson, H.M.; Brayton, M.J.; Vogel, J.R.

    2008-01-01

    Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic, mineralogical, chemical, dissolved gas, and isotopic data, were used to determine the processes controlling transport and fate of NO3- in streambeds at five sites across the USA. Water samples were collected from streambeds at depths ranging from 0.3 to 3 m at three to five points across the stream and in two to five separate transects. Residence times of water ranging from 0.28 to 34.7 d m-1 in the streambeds of N-rich watersheds played an important role in allowing denitrification to decrease NO3- concentrations. Where potential electron donors were limited and residence times were short, denitrification was limited. Consequently, in spite of reducing conditions at some sites, NO3- was transported into the stream. At two of the five study sites, NO3- in surface water infiltrated the streambeds and concentrations decreased, supporting current models that NO3- would be retained in N-rich streams. At the other three study sites, hydrogeologic controls limited or prevented infiltration of surface water into the streambed, and ground-water discharge contributed to NO 3- loads. Our results also show that in these low hydrologic-gradient systems, storm and other high-flow events can be important factors for increasing surface-water movement into streambeds. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  6. Methods for Using Ground-Water Model Predictions to Guide Hydrogeologic Data Collection, with Applications to the Death Valley Regional Ground-Water Flow System

    Energy Technology Data Exchange (ETDEWEB)

    Claire R. Tiedeman; M.C. Hill; F.A. D' Agnese; C.C. Faunt

    2001-07-31

    Calibrated models of ground-water systems can provide substantial information for guiding data collection. This work considers using such models to guide hydrogeologic data collection for improving model predictions, by identifying model parameters that are most important to the predictions. Identification of these important parameters can help guide collection of field data about parameter values and associated flow-system features that can lead to improved predictions. Methods for identifying parameters important to predictions include prediction scaled sensitivities (PSS), which account for uncertainty on individual parameters as well as prediction sensitivity to parameters, and a new ''value of improved information'' (VOII) method, which includes the effects of parameter correlation in addition to individual parameter uncertainty and prediction sensitivity. The PSS and VOII methods are demonstrated using a model of the Death Valley regional ground-water flow system. The predictions of interest are advective-transport paths originating at sites of past underground nuclear testing. Results show that for two paths evaluated, the most important parameters include a subset of five or six of the 23 defined model parameters. Some of the parameters identified as most important are associated with flow-system attributes that do not lie in the immediate vicinity of the paths. Results also indicate that the PSS and VOII methods can identify different important parameters. Because the methods emphasize somewhat different criteria for parameter importance, it is suggested that parameters identified by both methods be carefully considered in subsequent data collection efforts aimed at improving model predictions.

  7. Using MODFLOW 2000 to model ET and recharge for shallow ground water problems.

    Science.gov (United States)

    Doble, Rebecca C; Simmons, Craig T; Walker, Glen R

    2009-01-01

    In environments with shallow ground water elevation, small changes in the water table can cause significant variations in recharge and evapotranspiration fluxes. Particularly, where ground water is close to the soil surface, both recharge and evapotranspiration are regulated by a thin unsaturated zone and, for accuracy, must be represented using nonconstant and often nonlinear relationships. The most commonly used ground water flow model today, MODFLOW, was originally designed with a modular structure with independent packages representing recharge and evaporation processes. Systems with shallow ground water, however, may be better represented using either a recharge function that varies with ground water depth or a continuous recharge and evapotranspiration function that is dependent on depth to water table. In situations where the boundaries between recharging and nonrecharging cells change with time, such as near a seepage zone, a continuous ground water flux relationship allows recharge rates to change with depth rather than having to calculate them at each stress period. This research article describes the modification of the MODFLOW 2000 recharge and segmented evapotranspiration packages into a continuous recharge-discharge function that allows ground water flux to be represented as a continuous process, dependent on head. The modifications were then used to model long-term recharge and evapotranspiration processes on a saline, semiarid floodplain in order to understand spatial patterns of salinization, and an overview of this process is given.

  8. Vadose zone-attenuated artificial recharge for input to a ground water model.

    Science.gov (United States)

    Nichols, William E; Wurstner, Signe K; Eslinger, Paul W

    2007-01-01

    Accurate representation of artificial recharge is requisite to calibration of a ground water model of an unconfined aquifer for a semiarid or arid site with a vadose zone that imparts significant attenuation of liquid transmission and substantial anthropogenic liquid discharges. Under such circumstances, artificial recharge occurs in response to liquid disposal to the vadose zone in areas that are small relative to the ground water model domain. Natural recharge, in contrast, is spatially variable and occurs over the entire upper boundary of a typical unconfined ground water model. An improved technique for partitioning artificial recharge from simulated total recharge for inclusion in a ground water model is presented. The improved technique is applied using data from the semiarid Hanford Site. From 1944 until the late 1980s, when Hanford's mission was the production of nuclear materials, the quantities of liquid discharged from production facilities to the ground vastly exceeded natural recharge. Nearly all hydraulic head data available for use in calibrating a ground water model at this site were collected during this period or later, when the aquifer was under the diminishing influence of the massive water disposals. The vadose zone is typically 80 to 90 m thick at the Central Plateau where most production facilities were located at this semiarid site, and its attenuation of liquid transmission to the aquifer can be significant. The new technique is shown to improve the representation of artificial recharge and thereby contribute to improvement in the calibration of a site-wide ground water model.

  9. Guide to the Revised Ground-Water Flow and Heat Transport Simulator: HYDROTHERM - Version 3

    Science.gov (United States)

    Kipp, Kenneth L.; Hsieh, Paul A.; Charlton, Scott R.

    2008-01-01

    The HYDROTHERM computer program simulates multi-phase ground-water flow and associated thermal energy transport in three dimensions. It can handle high fluid pressures, up to 1 ? 109 pascals (104 atmospheres), and high temperatures, up to 1,200 degrees Celsius. This report documents the release of Version 3, which includes various additions, modifications, and corrections that have been made to the original simulator. Primary changes to the simulator include: (1) the ability to simulate unconfined ground-water flow, (2) a precipitation-recharge boundary condition, (3) a seepage-surface boundary condition at the land surface, (4) the removal of the limitation that a specified-pressure boundary also have a specified temperature, (5) a new iterative solver for the linear equations based on a generalized minimum-residual method, (6) the ability to use time- or depth-dependent functions for permeability, (7) the conversion of the program code to Fortran 90 to employ dynamic allocation of arrays, and (8) the incorporation of a graphical user interface (GUI) for input and output. The graphical user interface has been developed for defining a simulation, running the HYDROTHERM simulator interactively, and displaying the results. The combination of the graphical user interface and the HYDROTHERM simulator forms the HYDROTHERM INTERACTIVE (HTI) program. HTI can be used for two-dimensional simulations only. New features in Version 3 of the HYDROTHERM simulator have been verified using four test problems. Three problems come from the published literature and one problem was simulated by another partially saturated flow and thermal transport simulator. The test problems include: transient partially saturated vertical infiltration, transient one-dimensional horizontal infiltration, two-dimensional steady-state drainage with a seepage surface, and two-dimensional drainage with coupled heat transport. An example application to a hypothetical stratovolcano system with unconfined

  10. Simulation of ground-water flow and transport of chlorinated hydrocarbons at Graces Quarters, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Tenbus, Frederick J.; Fleck, William B.

    2001-01-01

    Military activity at Graces Quarters, a former open-air chemical-agent facility at Aberdeen Proving Ground, Maryland, has resulted in ground-water contamination by chlorinated hydrocarbons. As part of a ground-water remediation feasibility study, a three-dimensional model was constructed to simulate transport of four chlorinated hydrocarbons (1,1,2,2-tetrachloroethane, trichloroethene, carbon tetrachloride, and chloroform) that are components of a contaminant plume in the surficial and middle aquifers underlying the east-central part of Graces Quarters. The model was calibrated to steady-state hydraulic head at 58 observation wells and to the concentration of 1,1,2,2-tetrachloroethane in 58 observation wells and 101direct-push probe samples from the mid-1990s. Simulations using the same basic model with minor adjustments were then run for each of the other plume constituents. The error statistics between the simulated and measured concentrations of each of the constituents compared favorably to the error statisticst,1,2,2-tetrachloroethane calibration. Model simulations were used in conjunction with contaminant concentration data to examine the sources and degradation of the plume constituents. It was determined from this that mixed contaminant sources with no ambient degradation was the best approach for simulating multi-species solute transport at the site. Forward simulations were run to show potential solute transport 30 years and 100 years into the future with and without source removal. Although forward simulations are subject to uncertainty, they can be useful for illustrating various aspects of the conceptual model and its implementation. The forward simulation with no source removal indicates that contaminants would spread throughout various parts of the surficial and middle aquifers, with the100-year simulation showing potential discharge areas in either the marshes at the end of the Graces Quarters peninsula or just offshore in the estuaries. The

  11. Simulation of ground-water flow and solute transport in the Glen Canyon aquifer, East-Central Utah

    Science.gov (United States)

    Freethey, Geoffrey W.; Stolp, Bernard J.

    2010-01-01

    The extraction of methane from coal beds in the Ferron coal trend in central Utah started in the mid-1980s. Beginning in 1994, water from the extraction process was pressure injected into the Glen Canyon aquifer. The lateral extent of the aquifer that could be affected by injection is about 7,600 square miles. To address regional-scale effects of injection over a decadal time frame, a conceptual model of ground-water movement and transport of dissolved solids was formulated. A numerical model that incorporates aquifer concepts was then constructed and used to simulate injection. The Glen Canyon aquifer within the study area is conceptualized in two parts-an active area of ground-water flow and solute transport that exists between recharge areas in the San Rafael Swell and Desert, Waterpocket Fold, and Henry Mountains and discharge locations along the Muddy, Dirty Devil, San Rafael, and Green Rivers. An area of little or negligible ground-water flow exists north of Price, Utah, and beneath the Wasatch Plateau. Pressurized injection of coal-bed methane production water occurs in this area where dissolved-solids concentrations can be more than 100,000 milligrams per liter. Injection has the potential to increase hydrologic interaction with the active flow area, where dissolved-solids concentrations are generally less than 3,000 milligrams per liter. Pressurized injection of coal-bed methane production water in 1994 initiated a net addition of flow and mass of solutes into the Glen Canyon aquifer. To better understand the regional scale hydrologic interaction between the two areas of the Glen Canyon aquifer, pressurized injection was numerically simulated. Data constraints precluded development of a fully calibrated simulation; instead, an uncalibrated model was constructed that is a plausible representation of the conceptual flow and solute-transport processes. The amount of injected water over the 36-year simulation period is about 25,000 acre-feet. As a result

  12. A modelling approach to determine the origin of urban ground water.

    Science.gov (United States)

    Trowsdale, Sam A; Lerner, David N

    2007-04-01

    A simple modelling approach was developed to link patterns of urban land-use with ground water flow and chemistry in three dimensions and was applied to characterize the origin of recharge in the aquifer beneath the old industrial city of Nottingham, UK. The approach involved dividing land uses into types, and times into periods, and assigning the recharge from each an individual tracer-solute with a unit concentration. The computer code MT3DMS was used to track the multiple tracer-solutes in transient, three-dimensional simulations of the important urban aquifer. A depth-specific hydrochemical dataset collected in parallel supported the model predictions. At depth under the industrial area studied, a large component of ground water originated of older agricultural origin, with relatively low nitrate concentrations. Shallower ground water originated mainly from residential and industrial areas, with higher nitrate concentrations probably arising from leaking sewers and contaminated land. The results highlighted the spectrum of ground water from different origins that amalgamate even at short well screens in a non-pumped borehole and remind us that the non-point-source pollution of ground water from anthropogenic activities will involve more years of slow degradation of quality.

  13. STUDY OF INFLUENCE OF EFFLUENT ON GROUND WATER USING REMOTE SENSING, GIS AND MODELING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    S. Pathak

    2012-07-01

    Full Text Available The area lies in arid zone of western Rajasthan having very scanty rains and very low ground water reserves. Some of the other problems that are faced by the area are disposal of industrial effluent posing threat to its sustainability of water resource. Textiles, dyeing and printing industries, various mechanical process and chemical/synthetic dyes are used and considerable wastewater discharged from these textile units contains about high amount of the dyes into the adjoining drainages. This has caused degradation of water quality in this water scarce semi-arid region of the country. Pali city is located South-West, 70 Kms from Jodhpur in western Rajasthan (India. There are four Common Effluent Treatment Plant (CETP treating wastewater to meet the pollutant level permissible to river discharge, a huge amount of effluent water of these factories directly meets the into the river Bandi – a tributary of river Luni. In order to monitor the impact of industrial effluents on the environment, identifying the extent of the degradation and evolving possible means of minimizing the impacts studies on quality of effluents, polluted river water and water of adjoining wells, the contamination migration of the pollutants from the river to ground water were studied. Remote sensing analysis has been carried out using Resourcesat −1 multispectral satellite data along with DEM derived from IRS P5 stereo pair. GIS database generated of various thematic layers viz. base layer – inventorying all waterbodies in the vicinity, transport network and village layer, drainage, geomorphology, structure, land use. Analysis of spatial distribution of the features and change detection in land use/cover carried out. GIS maps have been used to help factor in spatial location of source and hydro-geomorphological settings. DEM & elevation contour helped in delineation of watershed and identifying flow modelling boundaries. Litholog data analysis carried out for aquifer

  14. Study of Influence of Effluent on Ground Water Using Remote Sensing, GIS and Modeling Techniques

    Science.gov (United States)

    Pathak, S.; Bhadra, B. K.; Sharma, J. R.

    2012-07-01

    The area lies in arid zone of western Rajasthan having very scanty rains and very low ground water reserves. Some of the other problems that are faced by the area are disposal of industrial effluent posing threat to its sustainability of water resource. Textiles, dyeing and printing industries, various mechanical process and chemical/synthetic dyes are used and considerable wastewater discharged from these textile units contains about high amount of the dyes into the adjoining drainages. This has caused degradation of water quality in this water scarce semi-arid region of the country. Pali city is located South-West, 70 Kms from Jodhpur in western Rajasthan (India). There are four Common Effluent Treatment Plant (CETP) treating wastewater to meet the pollutant level permissible to river discharge, a huge amount of effluent water of these factories directly meets the into the river Bandi - a tributary of river Luni. In order to monitor the impact of industrial effluents on the environment, identifying the extent of the degradation and evolving possible means of minimizing the impacts studies on quality of effluents, polluted river water and water of adjoining wells, the contamination migration of the pollutants from the river to ground water were studied. Remote sensing analysis has been carried out using Resourcesat -1 multispectral satellite data along with DEM derived from IRS P5 stereo pair. GIS database generated of various thematic layers viz. base layer - inventorying all waterbodies in the vicinity, transport network and village layer, drainage, geomorphology, structure, land use. Analysis of spatial distribution of the features and change detection in land use/cover carried out. GIS maps have been used to help factor in spatial location of source and hydro-geomorphological settings. DEM & elevation contour helped in delineation of watershed and identifying flow modelling boundaries. Litholog data analysis carried out for aquifer boundaries using specialized

  15. Ground-water flow modeling of the Culebra dolomite

    Energy Technology Data Exchange (ETDEWEB)

    LaVenue, A.M.; Cauffman, T.L.; Pickens, J.F. (INTERA, Inc., Austin, TX (USA))

    1990-10-01

    This hydrogeologic modeling study has been performed as part of the regional hydrologic characterization of the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico. The study has produced an estimation of the transmissivity and Darcy-velocity distributions in the Culebra Dolomite Member of the Permian Rustler Formation at the WIPP site. The results of this study are intended to support Sandia National Laboratories performance-assessment calculations. The three-dimensional finite-difference code SWIFT II was employed for the numerical modeling, using a variable-fluid-density and single-porosity formulation. The spatial scale of the model, 21.3 km by 30.6 km, was chosen to allow simulation of regional-scale pumping tests conducted at the H-3 and H-11 hydropads and the WIPP-13 borehole, which are located south, southeast, and northwest, respectively, of the center of the WIPP site. The modeled area includes and extends beyond the controlled area defined by the WIPP-site boundaries. The work performed in this study consisted of modeling the hydrogeology of the Culebra in two stages: steady-state modeling to develop the best estimate of the undisturbed head distribution (i.e., of the hydraulic conditions before excavation of the WIPP shafts, which began in 1981) and superimposed transient modeling of local hydrologic response to excavation of the four WIPP shafts at the center of the WIPP site, as well as to various well tests. The transient modeling used the calculated steady-state freshwater heads as initial conditions. 144 refs., 98 figs., 23 tabs.

  16. A theory for modeling ground-water flow in heterogeneous media

    Science.gov (United States)

    Cooley, Richard L.

    2004-01-01

    Construction of a ground-water model for a field area is not a straightforward process. Data are virtually never complete or detailed enough to allow substitution into the model equations and direct computation of the results of interest. Formal model calibration through optimization, statistical, and geostatistical methods is being applied to an increasing extent to deal with this problem and provide for quantitative evaluation and uncertainty analysis of the model. However, these approaches are hampered by two pervasive problems: 1) nonlinearity of the solution of the model equations with respect to some of the model (or hydrogeologic) input variables (termed in this report system characteristics) and 2) detailed and generally unknown spatial variability (heterogeneity) of some of the system characteristics such as log hydraulic conductivity, specific storage, recharge and discharge, and boundary conditions. A theory is developed in this report to address these problems. The theory allows construction and analysis of a ground-water model of flow (and, by extension, transport) in heterogeneous media using a small number of lumped or smoothed system characteristics (termed parameters). The theory fully addresses both nonlinearity and heterogeneity in such a way that the parameters are not assumed to be effective values. The ground-water flow system is assumed to be adequately characterized by a set of spatially and temporally distributed discrete values, ?, of the system characteristics. This set contains both small-scale variability that cannot be described in a model and large-scale variability that can. The spatial and temporal variability in ? are accounted for by imagining ? to be generated by a stochastic process wherein ? is normally distributed, although normality is not essential. Because ? has too large a dimension to be estimated using the data normally available, for modeling purposes ? is replaced by a smoothed or lumped approximation y?. (where y is a

  17. Modeling surface and ground water mixing in the hyporheic zone using MODFLOW and MT3D

    Science.gov (United States)

    Lautz, Laura K.; Siegel, Donald I.

    2006-11-01

    We used a three-dimensional MODFLOW model, paired with MT3D, to simulate hyporheic zones around debris dams and meanders along a semi-arid stream. MT3D simulates both advective transport and sink/source mixing of solutes, in contrast to particle tracking (e.g. MODPATH), which only considers advection. We delineated the hydrochemically active hyporheic zone based on a new definition, specifically as near-stream subsurface zones receiving a minimum of 10% surface water within a 10-day travel time. Modeling results indicate that movement of surface water into the hyporheic zone is predominantly an advective process. We show that debris dams are a key driver of surface water into the subsurface along the experimental reach, causing the largest flux rates of water across the streambed and creating hyporheic zones with up to twice the cross-sectional area of other hyporheic zones. Hyporheic exchange was also found in highly sinuous segments of the experimental reach, but flux rates are lower and the cross-sectional areas of these zones are generally smaller. Our modeling approach simulated surface and ground water mixing in the hyporheic zone, and thus provides numerical approximations that are more comparable to field-based observations of surface-groundwater exchange than standard particle-tracking simulations.

  18. Modeling analysis of ground water recharge potential on alluvial fans using limited data.

    Science.gov (United States)

    Munévar, A; Mariño, M A

    1999-01-01

    A modeling approach is developed to evaluate the potential for artificial recharge on alluvial fans in the Salinas Valley, California, using limited data of soil texture, soil hydraulic properties, and interwell stratigraphy. Promising areas for surface recharge are identified and mapped on a broad-scale using soil surveys, geologic investigations, permeability tests, and seasonal ground water response to rainfall and runoff. Two-dimensional representations of the vadose zone at selected sites are then constructed from drillers'logs and soil material types are estimated. Next, hydraulic properties are assigned to each soil material type by comparing them to laboratory-tested cores of similar soils taken from one site. Finally, water flow through the vadose zone is modeled in two dimensions at seven sites using a transient, finite-difference, variably saturated flow model. Average infiltration rates range from 0.84 to 1.54 cm/hr and recharge efficiency, the percentage of infiltrated water that reaches the water table, varies from 51% to 79%. Infiltration rates and recharge efficiency are found to be relatively insensitive to recharge basin ponding depth due to the thickness of the vadose zones modeled (31 to 84 m). The impact of artificial recharge on the Salinas Valley ground water basin is investigated by simulating the regional ground water response to surface spreading and streamflow augmentation with a recently calibrated, finite-element, ground water-surface water model for the basin. It was determined that a combined approach of surface recharge and streamflow augmentation significantly reduces the state of ground water overdraft and, to a lesser extent, reduces the rate of sea water intrusion.

  19. The value of long-term monitoring in the development of ground-water-flow models

    Science.gov (United States)

    Feinstein, Daniel T.; Hart, David J.; Krohelski, James T.

    2004-01-01

    As environmental issues have come to the forefront of public concern, so has the awareness of the importance of ground water in the overall water cycle and as a source of the Nation’s drinking water. Heightened interest has spawned a host of scientific enterprises (Taylor and Alley, 2001). Some activities are directed toward collection of water-level data and related information to monitor the physical and chemical state of the resource. Other activities are directed at interpretive studies undertaken, for example, to optimize the location of new water-supply wells or to protect rivers and lakes fed by ground water. An important type of interpretive study is the computer ground-water-flow model that inte- grates field data in a mathematical framework. Long-term, systematic collection of hydro- logic data is crucial to the construction and testing of ground-water models so that they can reproduce the evolution of flow systems and forecast future conditions. 

  20. Documentation of finite-difference model for simulation of three-dimensional ground-water flow

    Science.gov (United States)

    Trescott, Peter C.; Larson, S.P.

    1976-01-01

    User experience has indicated that the documentation of the model of three-dimensional ground-water flow (Trescott and Larson, 1975) should be expanded. This supplement is intended to fulfill that need. The original report emphasized the theory of the strongly implicit procedure, instructions for using the groundwater-flow model, and practical considerations for application. (See also W76-02962 and W76-13085) (Woodard-USGS)

  1. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 21. Ground water movement and nuclide transport

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-01

    This volume, TM-36/21 Ground Water Movement and Nuclide Transport, is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-36'' which supplements a ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-44.'' The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling of spent fuel and uranium-only recycling. The studies presented in this volume consider the effect of the construction of the repository and the consequent heat generation on the ground water movement. Additionally, the source concentrations and leach rates of selected radionuclides were studied in relation to the estimated ground water inflow rates. Studies were also performed to evaluate the long term migration of radionuclides as affected by the ground water flow. In all these studies, three geologic environments are considered; granite, shale and basalt.

  2. Material-property zones used in the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Zones in this data set represent spatially contiguous areas that influence ground-water flow in the Death Valley regional ground-water flow system (DVRFS), an...

  3. Material-property zones used in the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Zones in this data set represent spatially contiguous areas that influence ground-water flow in the Death Valley regional ground-water flow system (DVRFS), an...

  4. Documentation of the Santa Clara Valley regional ground-water/surface-water flow model, Santa Clara Valley, California

    Science.gov (United States)

    Hanson, R.T.; Li, Zhen; Faunt, C.C.

    2004-01-01

    The Santa Clara Valley is a long, narrow trough extending about 35 miles southeast from the southern end of San Francisco Bay where the regional alluvial-aquifer system has been a major source of water. Intensive agricultural and urban development throughout the 20th century and related ground-water development resulted in ground-water-level declines of more than 200 feet and land subsidence of as much as 12.7 feet between the early 1900s and the mid-1960s. Since the 1960s, Santa Clara Valley Water District has imported surface water to meet growing demands and reduce dependence on ground-water supplies. This importation of water has resulted in a sustained recovery of the ground-water flow system. To help support effective management of the ground-water resources, a regional ground-water/surface-water flow model was developed. This model simulates the flow of ground water and surface water, changes in ground-water storage, and related effects such as land subsidence. A numerical ground-water/surface-water flow model of the Santa Clara Valley subbasin of the Santa Clara Valley was developed as part of a cooperative investigation with the Santa Clara Valley Water District. The model better defines the geohydrologic framework of the regional flow system and better delineates the supply and demand components that affect the inflows to and outflows from the regional ground-water flow system. Development of the model includes revisions to the previous ground-water flow model that upgraded the temporal and spatial discretization, added source-specific inflows and outflows, simulated additional flow features such as land subsidence and multi-aquifer wellbore flow, and extended the period of simulation through September 1999. The transient-state model was calibrated to historical surface-water and ground-water data for the period 197099 and to historical subsidence for the period 198399. The regional ground-water flow system consists of multiple aquifers that are grouped

  5. Geostatical Modelling For Ground Water Pollution in Salem by Using Gis

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-06-01

    Full Text Available Ground waters are the major resources to meet out the entire requirements. Pollution of air, water and land has an effect on the quality of the ground waters. The chemical characteristics of groundwater in Salem taluk of Salem district have been studied using Geostatistical modeling to evaluate the suitability of water for irrigation and domestic uses. The 32 water samples from PWD wells taken during the years 1999 to 2009 for post monsson and pre monsoon were tested for various chemical parameters like pH and TDS .The Geostatistical analyst of mean, mode, standard deviation, cluster & simple to study the spatial pattern of contamination movement for the years 1999 to 2009. Trend analysis was performed to identify trends in the input dataset. The concentrations of physical and chemical constituents in the water samples were compared with the World Health Organization (WHO standard to know the suitability of water for drinking.

  6. Simulations of Ground-Water Flow, Transport, Age, and Particle Tracking near York, Nebraska, for a Study of Transport of Anthropogenic and Natural Contaminants (TANC) to Public-Supply Wells

    Science.gov (United States)

    Clark, Brian R.; Landon, Matthew K.; Kauffman, Leon J.; Hornberger, George Z.

    2008-01-01

    Contamination of public-supply wells has resulted in public-health threats and negative economic effects for communities that must treat contaminated water or find alternative water supplies. To investigate factors controlling vulnerability of public-supply wells to anthropogenic and natural contaminants using consistent and systematic data collected in a variety of principal aquifer settings in the United States, a study of Transport of Anthropogenic and Natural Contaminants to public-supply wells was begun in 2001 as part of the U.S. Geological Survey National Water-Quality Assessment Program. The area simulated by the ground-water flow model described in this report was selected for a study of processes influencing contaminant distribution and transport along the direction of ground-water flow towards a public-supply well in southeastern York, Nebraska. Ground-water flow is simulated for a 60-year period from September 1, 1944, to August 31, 2004. Steady-state conditions are simulated prior to September 1, 1944, and represent conditions prior to use of ground water for irrigation. Irrigation, municipal, and industrial wells were simulated using the Multi-Node Well package of the modular three-dimensional ground-water flow model code, MODFLOW-2000, which allows simulation of flow and solutes through wells that are simulated in multiple nodes or layers. Ground-water flow, age, and transport of selected tracers were simulated using the Ground-Water Transport process of MODFLOW-2000. Simulated ground-water age was compared to interpreted ground-water age in six monitoring wells in the unconfined aquifer. The tracer chlorofluorocarbon-11 was simulated directly using Ground-Water Transport for comparison with concentrations measured in six monitoring wells and one public supply well screened in the upper confined aquifer. Three alternative model simulations indicate that simulation results are highly sensitive to the distribution of multilayer well bores where leakage

  7. Boundary of the ground-water flow model by D'Agnese and others (1997), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the ground-water flow model by D'Agnese and others (1997). This steady-state, 3-layer ground-water flow model was...

  8. Estimating ground water recharge using flow models of perched karstic aquifers.

    Science.gov (United States)

    Weiss, Menachem; Gvirtzman, Haim

    2007-01-01

    The fraction of rain that is annually recharged to ground water is a function of the transient quantities of precipitation (wet vs. dry years) as well as other meteorological and geologic factors, and thus it is very difficult to estimate. In this study, we have used long records (20 to 30 years) of precipitation and spring discharge to reconstruct the transient character of yearly recharge. These data sets were used to calibrate numerical ground water flow models on the less than 3 km(2) scale for four separate perched karstic aquifers in the Judean and Samarian Mountains of Israel. The stratification and karstic character of the local carbonate rock aquifers cause ground water to flow through discrete dissolution channels and to discharge at isolated springs. An innovative, dual-porosity approach was used where a finite-difference solution simulates flow in the rock matrix, while the karstic channels are simulated using computationally simple drains. Perched conditions are also simulated innovatively using MODFLOW by treating the bottom unsaturated layer as if it is saturated, but by assuming zero pressure head throughout the "unsaturated" layer. Best fitting between measured and computed spring hydrograph data has allowed us to develop a set of empirical functions relating measured precipitation to recharge to the aquifer. The generic methodology presented gives insight into the suspected changes in aquifer recharge rates between particularly wet or dry years.

  9. Testing alternative ground water models using cross-validation and other methods

    Science.gov (United States)

    Foglia, L.; Mehl, S.W.; Hill, M.C.; Perona, P.; Burlando, P.

    2007-01-01

    Many methods can be used to test alternative ground water models. Of concern in this work are methods able to (1) rank alternative models (also called model discrimination) and (2) identify observations important to parameter estimates and predictions (equivalent to the purpose served by some types of sensitivity analysis). Some of the measures investigated are computationally efficient; others are computationally demanding. The latter are generally needed to account for model nonlinearity. The efficient model discrimination methods investigated include the information criteria: the corrected Akaike information criterion, Bayesian information criterion, and generalized cross-validation. The efficient sensitivity analysis measures used are dimensionless scaled sensitivity (DSS), composite scaled sensitivity, and parameter correlation coefficient (PCC); the other statistics are DFBETAS, Cook's D, and observation-prediction statistic. Acronyms are explained in the introduction. Cross-validation (CV) is a computationally intensive nonlinear method that is used for both model discrimination and sensitivity analysis. The methods are tested using up to five alternative parsimoniously constructed models of the ground water system of the Maggia Valley in southern Switzerland. The alternative models differ in their representation of hydraulic conductivity. A new method for graphically representing CV and sensitivity analysis results for complex models is presented and used to evaluate the utility of the efficient statistics. The results indicate that for model selection, the information criteria produce similar results at much smaller computational cost than CV. For identifying important observations, the only obviously inferior linear measure is DSS; the poor performance was expected because DSS does not include the effects of parameter correlation and PCC reveals large parameter correlations. ?? 2007 National Ground Water Association.

  10. Lateral boundary of the steady-state ground-water flow model by D'Agnese and others (2002), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the lateral boundary of the area simulated by the steady-state ground-water flow model of the Death Valley regional ground-water flow...

  11. Simulated potentiometric surface contours at end of simulation (1998) in model layer 1 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These contours represent the simulated potentiometric surface at the end of simulation (1998) in model layer 1 of the Death Valley regional ground-water flow system...

  12. Simulated potentiometric surface contours at end of simulation (1998) in model layer 16 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These contours represent the simulated potentiometric surface at the end of simulation (1998) in model layer 16 of the Death Valley regional ground-water flow system...

  13. Simulated potentiometric surface contours at end of simulation (1998) in model layer 1 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These contours represent the simulated potentiometric surface at the end of simulation (1998) in model layer 1 of the Death Valley regional ground-water flow system...

  14. Simulated potentiometric surface contours at end of simulation (1998) in model layer 16 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These contours represent the simulated potentiometric surface at the end of simulation (1998) in model layer 16 of the Death Valley regional ground-water flow...

  15. User's guide to Model Viewer, a program for three-dimensional visualization of ground-water model results

    Science.gov (United States)

    Hsieh, Paul A.; Winston, Richard B.

    2002-01-01

    Model Viewer is a computer program that displays the results of three-dimensional groundwater models. Scalar data (such as hydraulic head or solute concentration) may be displayed as a solid or a set of isosurfaces, using a red-to-blue color spectrum to represent a range of scalar values. Vector data (such as velocity or specific discharge) are represented by lines oriented to the vector direction and scaled to the vector magnitude. Model Viewer can also display pathlines, cells or nodes that represent model features such as streams and wells, and auxiliary graphic objects such as grid lines and coordinate axes. Users may crop the model grid in different orientations to examine the interior structure of the data. For transient simulations, Model Viewer can animate the time evolution of the simulated quantities. The current version (1.0) of Model Viewer runs on Microsoft Windows 95, 98, NT and 2000 operating systems, and supports the following models: MODFLOW-2000, MODFLOW-2000 with the Ground-Water Transport Process, MODFLOW-96, MOC3D (Version 3.5), MODPATH, MT3DMS, and SUTRA (Version 2D3D.1). Model Viewer is designed to directly read input and output files from these models, thus minimizing the need for additional postprocessing. This report provides an overview of Model Viewer. Complete instructions on how to use the software are provided in the on-line help pages.

  16. Isostatic gravity map of the Death Valley ground-water model area, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    Ponce, D.A.; Blakely, R.J.; Morin, R.L.; Mankinen, E.A.

    2002-03-12

    Gravity investigations of the Death Valley ground-water model area are part of an interagency effort by the U.S. Geological Survey (USGS) and the U.S. Department of Energy (Interagency agreement DE-AI08-96NV11967) to help characterize the geology and hydrology of southwestern Nevada and parts of California. The Death Valley ground-water model is located between lat 35 degrees 00' and 38 degrees 15' N., and long 115 degrees and 118 degrees W. An isostatic gravity map of the Death Valley ground-water model was prepared from over 40,000 gravity stations, most of which are publicly available on a CD-ROM of gravity data of Nevada (Ponce, 1997). The map also includes gravity data recently collected by the U.S. Geological Survey (Mankinen and others, 1998; Morin and Blakely, 1999). A subset of these gravity data in the Nevada Test Site and vicinity were described in detail by Harris and others (1989) who included information on gravity meters used, dates of collection, sources, descriptions of base stations, plots of data, and digital and paper lists of principal facts. For display purposes only, gravity data within Yucca Flat were thinned by a factor of 10. The digital gravity data set was gridded at an interval of 400 m using a computer program (Webring, 1981) based on a minimum curvature algorithm by Briggs (1974). The resulting grid was then interpolated to a 200-m grid to minimize pixel size, and then it was color contoured.

  17. Questa baseline and pre-mining ground-water quality investigation. 12. Geochemical and reactive-transport modeling based on tracer injection-synoptic sampling studies for the Red River, New Mexico, 2001-2002

    Science.gov (United States)

    Ball, James W.; Runkel, Robert L.; Nordstrom, D. Kirk

    2005-01-01

    Reactive-transport processes in the Red River, downstream from the town of Red River in north-central New Mexico, were simulated using the OTEQ reactive-transport model. The simulations were calibrated using physical and chemical data from synoptic studies conducted during low-flow conditions in August 2001 and during March/April 2002. Discharge over the 20-km reach from the town of Red River to the USGS streamflow-gaging station near the town of Questa ranged from 395 to 1,180 L/s during the 2001 tracer and from 234 to 421 L/s during the 2002 tracer. The pH of the Red River ranged from 7.4 to 8.5 during the 2001 tracer and from 7.1 to 8.7 during the 2002 tracer, and seep and tributary samples had pH values of 2.8 to 9.0 during the 2001 tracer and 3.8 to 7.2 during the 2002 tracer. Mass-loading calculations allowed identification of several specific locations where elevated concentrations of potential contaminants entered the Red River . These locations, characterized by features on the north side of the Red River that are known to be sources of low-pH water containing elevated metal and sulfate concentrations, are: the initial 2.4 km of the study reach, including Bitter Creek, the stream section from 6.2 to 7.8 km, encompassing La Bobita well and the Hansen debris fan, Sulphur Gulch, at about 10.5 km, the area near Portal Springs, from 12.2 to 12.6 km, and the largest contributors of mass loading, the 13.7 to 13.9 km stream section near Cabin Springs and the 14.7 to 17.5 km stream section from Shaft Spring to Thunder Bridge, Goathill Gulch, and Capulin Canyon. Speciation and saturation index calculations indicated that although solubility limits the concentration of aluminum above pH 5.0, at pH values above 7 and aluminum concentrations below 0.3 mg/L inorganic speciation and mineral solubility controls no longer dominate and aluminum-organic complexing may occur. The August 2001 reactive-transport simulations included dissolved iron(II) oxidation, constrained

  18. Thermal use of ground water; Thermische Grundwassernutzung

    Energy Technology Data Exchange (ETDEWEB)

    Cathomen, N.; Stauffer, F.; Kinzelbach, W.; Osterkorn, F.

    2002-07-01

    This article discusses possible regional changes in ground water temperature caused by thermal use of the ground water in heat pump installations and by the infiltration of cooling water. The article reports on investigations made into the influence of ground water usage in the community of Altach in the Rhine Valley in Austria. The procedures used and the geology of the area investigated are described and the results of the measurements that were made are presented. The mathematical modelling of regional long-term heat transport is presented. The results of simulations are compared with long-term temperature measurements. The use of the results as a basis for the assessment of permissible thermal use of ground water is discussed.

  19. User Guide and Documentation for Five MODFLOW Ground-Water Modeling Utility Programs

    Science.gov (United States)

    Banta, Edward R.; Paschke, Suzanne S.; Litke, David W.

    2008-01-01

    This report documents five utility programs designed for use in conjunction with ground-water flow models developed with the U.S. Geological Survey's MODFLOW ground-water modeling program. One program extracts calculated flow values from one model for use as input to another model. The other four programs extract model input or output arrays from one model and make them available in a form that can be used to generate an ArcGIS raster data set. The resulting raster data sets may be useful for visual display of the data or for further geographic data processing. The utility program GRID2GRIDFLOW reads a MODFLOW binary output file of cell-by-cell flow terms for one (source) model grid and converts the flow values to input flow values for a different (target) model grid. The spatial and temporal discretization of the two models may differ. The four other utilities extract selected 2-dimensional data arrays in MODFLOW input and output files and write them to text files that can be imported into an ArcGIS geographic information system raster format. These four utilities require that the model cells be square and aligned with the projected coordinate system in which the model grid is defined. The four raster-conversion utilities are * CBC2RASTER, which extracts selected stress-package flow data from a MODFLOW binary output file of cell-by-cell flows; * DIS2RASTER, which extracts cell-elevation data from a MODFLOW Discretization file; * MFBIN2RASTER, which extracts array data from a MODFLOW binary output file of head or drawdown; and * MULT2RASTER, which extracts array data from a MODFLOW Multiplier file.

  20. Simulated potentiometric surface contours of prepumping conditions in layer 1 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These simulated potentiometric surface contours represent prepumping (or steady-state) conditions for model layer 1 of the Death Valley regional ground-water flow...

  1. Simulated potentiometric surface contours of prepumping conditions in layer 16 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These simulated potentiometric surface contours represent prepumping (or steady-state) conditions for model layer 16 of the Death Valley regional ground-water flow...

  2. Biogeochemical Processes Responsible for the Enhanced Transport of Plutonium Under transient Unsaturated Ground Water Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fred J. Molz, III

    2010-05-28

    To better understand longer-term vadose zone transport in southeastern soils, field lysimeter experiments were conducted at the Savannah River Site (SRS) near Aiken, SC, in the 1980s. Each of the three lysimeters analyzed herein contained a filter paper spiked with different Pu solutions, and they were left exposed to natural environmental conditions (including the growth of annual weed grasses) for 11 years. The resulting Pu activity measurements from each lysimeter core showed anomalous activity distributions below the source, with significant migration of Pu above the source. Such results are not explainable by adsorption phenomena alone. A transient variably saturated flow model with root water uptake was developed and coupled to a soil reactive transport model. Somewhat surprisingly, the fully transient analysis showed results nearly identical to those of a much simpler steady flow analysis performed previously. However, all phenomena studied were unable to produce the upward Pu transport observed in the data. This result suggests another transport mechanism such as Pu uptake by roots and upward transport due to transpiration. Thus, the variably saturated flow and reactive transport model was extended to include uptake and transport of Pu within the root xylem, along with computational methodology and results. In the extended model, flow velocity in the soil was driven by precipitation input along with transpiration and drainage. Water uptake by the roots determined the flow velocity in the root xylem, and this along with uptake of Pu in the transpiration stream drove advection and dispersion of the two Pu species in the xylem. During wet periods with high potential evapotranspiration, maximum flow velocities through the xylem would approached 600 cm/hr, orders of magnitude larger that flow velocities in the soil. Values for parameters and the correct conceptual viewpoint for Pu transport in plant xylem was uncertain. This motivated further experiments devoted

  3. Simulated constant-head boundary for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents the constant head-boundary used to simulate ground-water inflow or outflow at the lateral boundary of the Death Valley regional...

  4. Horizontal flow barriers for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the surface traces of regional features simulated as horizontal flow barriers in the Death Valley regional ground-water flow system...

  5. Horizontal flow barriers for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the surface traces of regional features simulated as horizontal flow barriers in the Death Valley regional ground-water flow system...

  6. Simulated constant-head boundary for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents the constant head-boundary used to simulate ground-water inflow or outflow at the lateral boundary of the Death Valley regional...

  7. Radon (222Rn) in ground water of fractured rocks: A diffusion/ion exchange model

    Science.gov (United States)

    Wood, W.W.; Kraemer, T.F.; Shapiro, A.

    2004-01-01

    Ground waters from fractured igneous and high-grade sialic metamorphic rocks frequently have elevated activity of dissolved radon (222Rn). A chemically based model is proposed whereby radium (226Ra) from the decay of uranium (238U) diffuses through the primary porosity of the rock to the water-transmitting fracture where it is sorbed on weathering products. Sorption of 226Ra on the fracture surface maintains an activity gradient in the rock matrix, ensuring a continuous supply of 226Ra to fracture surfaces. As a result of the relatively long half-life of 226Ra (1601 years), significant activity can accumulate on fracture surfaces. The proximity of this sorbed 226Ra to the active ground water flow system allows its decay progeny 222Rn to enter directly into the water. Laboratory analyses of primary porosity and diffusion coefficients of the rock matrix, radon emanation, and ion exchange at fracture surfaces are consistent with the requirements of a diffusion/ion- exchange model. A dipole-brine injection/withdrawal experiment conducted between bedrock boreholes in the high-grade metamorphic and granite rocks at the Hubbard Brook Experimental Forest, Grafton County, New Hampshire, United States (42??56???N, 71??43???W) shows a large activity of 226Ra exchanged from fracture surfaces by a magnesium brine. The 226Ra activity removed by the exchange process is 34 times greater than that of 238U activity. These observations are consistent with the diffusion/ion-exchange model. Elutriate isotopic ratios of 223Ra/226Ra and 238U/226Ra are also consistent with the proposed chemically based diffusion/ion-exchange model.

  8. Fate and transport of pesticides in the ground water systems of southwest Georgia, 1993-2005

    Science.gov (United States)

    Dalton, M.S.; Frick, E.A.

    2008-01-01

    Modern agricultural practices in the United States have resulted in nearly unrivaled efficiency and productivity. Unfortunately, there is also the potential for release of these compounds to the environment and consequent adverse affects on wildlife and human populations. Since 1993, the National Water-Quality Assessment (NAWQA) program of the U.S. Geological Survey has evaluated water quality in agricultural areas to address these concerns. The objective of this study is to evaluate trends in pesticide concentrations from 1993-2005 in the surficial and Upper Floridan aquifers of southwest Georgia using pesticide and pesticide degradate data collected for the NAWQA program. There were six compounds - five herbicides and one degradate - that were detected in more than 20% of samples: atrazine, deethylatrazine (DEA), metolachlor, alachlor, floumeturon, and tebuthiuron. Of the 128 wells sampled during the study, only eight wells had pesticide concentrations that either increased (7) or decreased (1) on a decadal time scale. Most of the significant trends were increasing concentrations of pesticides in older water; median pesticide concentrations did not differ between the surficial and Upper Floridan aquifers from 1993 and 2005. Deethylatrazine, in the Upper Floridan aquifer, was the only compound that had a significant change (increase) in concentration during the study. The limited number of wells with increases in pesticide concentrations suggest that ground-water sources of these compounds are not increasing in concentration over the time scale represented in this study. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  9. Computer simulation models relevant to ground water contamination from EOR or other fluids - state-of-the-art

    Energy Technology Data Exchange (ETDEWEB)

    Kayser, M.B.; Collins, A.G.

    1986-03-01

    Ground water contamination is a serious national problem. The use of computers to simulate the behavior of fluids in the subsurface has proliferated extensively over the last decade. Numerical models are being used to solve water supply problems, various kinds of enertgy production problems, and ground water contamination problems. Modeling techniques have progressed to the point that their accuracy is only limited by the modeller's ability to describe the reservoir in question and the heterogeneities therein. Pursuant to the Task and Milestone Update of Project BE3A, this report summarizes the state of the art of computer simulation models relevant to contamination of ground water by enhanced oil recovery (EOR) chemicals and/or waste fluids. 150 refs., 6 tabs.

  10. Well-response model of the confined area, Bunker Hill ground-water basin, San Bernardino County, California

    Science.gov (United States)

    Durbin, Timothy J.; Morgan, Charles O.

    1978-01-01

    The Bunker Hill ground-water basin, in the vicinity of San Bernardino, Calif., is being artificially recharged with imported water. Current and future artificial recharge of the basin may cause the potentiometric surface in an area of confined ground water to rise above land surface and water to flow from uncapped and unplugged wells. This could cause damage to structures where the soil becomes waterlogged and where buried wells begin to flow beneath the structures. A well-response model was used to generate a series of water-level hydrographs representing the response of the ground-water basin to six possible combinations of conditions for each well; one pumping rate, two artificial-recharge rate, and three natural-recharge rates. Inflow to the ground-water basin exceeds outflow for all tested combinations. According to model predictions, the accumulation of stored ground water resulting from the excess of inflow is sufficient to cause the water level in the selected wells to rise above land surface for all but one of the combinations of conditions tested. Water levels in wells are predicted to rise above the land surface as early as 1981 for the combination with the greatest excess of inflow. (Woodard-USGS)

  11. GSFLOW - Coupled Ground-Water and Surface-Water Flow Model Based on the Integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005)

    Science.gov (United States)

    Markstrom, Steven L.; Niswonger, Richard G.; Regan, R. Steven; Prudic, David E.; Barlow, Paul M.

    2008-01-01

    The need to assess the effects of variability in climate, biota, geology, and human activities on water availability and flow requires the development of models that couple two or more components of the hydrologic cycle. An integrated hydrologic model called GSFLOW (Ground-water and Surface-water FLOW) was developed to simulate coupled ground-water and surface-water resources. The new model is based on the integration of the U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) and the U.S. Geological Survey Modular Ground-Water Flow Model (MODFLOW). Additional model components were developed, and existing components were modified, to facilitate integration of the models. Methods were developed to route flow among the PRMS Hydrologic Response Units (HRUs) and between the HRUs and the MODFLOW finite-difference cells. This report describes the organization, concepts, design, and mathematical formulation of all GSFLOW model components. An important aspect of the integrated model design is its ability to conserve water mass and to provide comprehensive water budgets for a location of interest. This report includes descriptions of how water budgets are calculated for the integrated model and for individual model components. GSFLOW provides a robust modeling system for simulating flow through the hydrologic cycle, while allowing for future enhancements to incorporate other simulation techniques.

  12. Application of nonlinear-regression methods to a ground-water flow model of the Albuquerque Basin, New Mexico

    Science.gov (United States)

    Tiedeman, C.R.; Kernodle, J.M.; McAda, D.P.

    1998-01-01

    This report documents the application of nonlinear-regression methods to a numerical model of ground-water flow in the Albuquerque Basin, New Mexico. In the Albuquerque Basin, ground water is the primary source for most water uses. Ground-water withdrawal has steadily increased since the 1940's, resulting in large declines in water levels in the Albuquerque area. A ground-water flow model was developed in 1994 and revised and updated in 1995 for the purpose of managing basin ground- water resources. In the work presented here, nonlinear-regression methods were applied to a modified version of the previous flow model. Goals of this work were to use regression methods to calibrate the model with each of six different configurations of the basin subsurface and to assess and compare optimal parameter estimates, model fit, and model error among the resulting calibrations. The Albuquerque Basin is one in a series of north trending structural basins within the Rio Grande Rift, a region of Cenozoic crustal extension. Mountains, uplifts, and fault zones bound the basin, and rock units within the basin include pre-Santa Fe Group deposits, Tertiary Santa Fe Group basin fill, and post-Santa Fe Group volcanics and sediments. The Santa Fe Group is greater than 14,000 feet (ft) thick in the central part of the basin. During deposition of the Santa Fe Group, crustal extension resulted in development of north trending normal faults with vertical displacements of as much as 30,000 ft. Ground-water flow in the Albuquerque Basin occurs primarily in the Santa Fe Group and post-Santa Fe Group deposits. Water flows between the ground-water system and surface-water bodies in the inner valley of the basin, where the Rio Grande, a network of interconnected canals and drains, and Cochiti Reservoir are located. Recharge to the ground-water flow system occurs as infiltration of precipitation along mountain fronts and infiltration of stream water along tributaries to the Rio Grande; subsurface

  13. Multidisciplinary Studies of the Fate and Transport of Contaminants in Ground Water at the U.S. Geological Survey Cape Cod Toxic Substances Hydrology Program Research Site, Massachusetts

    Science.gov (United States)

    Leblanc, D. R.; Smith, R. L.; Kent, D. B.; Barber, L. B.; Harvey, R. W.

    2008-12-01

    The U.S. Geological Survey conducts multidisciplinary research on the physical, chemical, and microbiological processes affecting ground-water contaminants of global concern at its Cape Cod Toxic Substances Hydrology Program site in Massachusetts, USA. The work centers on a 6-kilometer-long plume of treated wastewater in a glacial sand and gravel aquifer. The plume is characterized by distinct geochemical zones caused by the biodegradation of organic materials in treated wastewater that was disposed to the aquifer by rapid infiltration during the period 1936-95. A core group of hydrogeologists, geochemists, microbiologists, and geophysicists has been involved in the research effort for more than two decades. The effort has been enhanced by stable funding, a readily accessible site, a relatively simple hydrologic setting, and logistical support from an adjacent military base. The research team uses a three-part approach to plan and conduct research at the site. First, detailed spatial and temporal monitoring of the plume since the late 1970s provides field evidence of important contaminant-transport processes and provides the basis for multidisciplinary, process-oriented studies. Second, ground-water tracer experiments are conducted in various geochemical zones in the plume to study factors that control the rate and extent of contaminant transport. Several arrays of multilevel sampling devices, including an array with more than 15,000 individual sampling points, are used to conduct these experiments. Plume-scale (kilometers) and tracer-test-scale (1- 100 meters) studies are complemented by laboratory experiments and mathematical modeling of flow and reactive transport. Third, results are applied to the treated-wastewater plume, other contaminant plumes at the military base, and other sites nationally to evaluate the applicability of the findings and to point toward further research. Examples of findings to date include that (1) macrodispersivity can be related to

  14. Geohydrological characterization, water-chemistry, and ground-water flow simulation model of the Sonoma Valley area, Sonoma County, California

    Science.gov (United States)

    Farrar, Christopher D.; Metzger, Loren F.; Nishikawa, Tracy; Koczot, Kathryn M.; Reichard, Eric G.; Langenheim, V.E.

    2006-01-01

    The Sonoma Valley, located about 30 miles north of San Francisco, is one of several basins in Sonoma County that use a combination of ground water and water delivered from the Russian River for supply. Over the past 30 years, Sonoma Valley has experienced rapid population growth and land-use changes. In particular, there has been a significant increase in irrigated agriculture, predominantly vineyards. To provide a better understanding of the ground-water/surface-water system in Sonoma Valley, the U.S. Geological Survey compiled and evaluated existing data, collected and analyzed new data, and developed a ground-water flow model to better understand and manage the ground-water system. The new data collected include subsurface lithology, gravity measurements, groundwater levels, streamflow gains and losses, temperature, water chemistry, and stable isotopes. Sonoma Valley is drained by Sonoma Creek, which discharges into San Pablo Bay. The long-term average annual volume of precipitation in the watershed is estimated to be 269,000 acre-feet. Recharge to the ground-water system is primarily from direct precipitation and Sonoma Creek. Discharge from the ground-water system is predominantly outflow to Sonoma Creek, pumpage, and outflow to marshlands and to San Pablo Bay. Geologic units of most importance for groundwater supply are the Quaternary alluvial deposits, the Glen Ellen Formation, the Huichica Formation, and the Sonoma Volcanics. In this report, the ground-water system is divided into three depth-based geohydrologic units: upper (less than 200 feet below land surface), middle (between 200 and 500 feet), and lower (greater than 500 feet). Synoptic streamflow measurements were made along Sonoma Creek and indicate those reaches with statistically significant gains or losses. Changes in ground-water levels in wells were analyzed by comparing historical contour maps with the contour map for 2003. In addition, individual hydrographs were evaluated to assess temporal

  15. Fact Sheet: Documenting Ground-Water Models Selection at Site Contaminated with Radioactive Substance

    Science.gov (United States)

    This fact sheet summarizes the report by a joint Interagency Environmental Pathway Modeling Working Group. It was designed to be used by technical staff responsible for identifying and implementing flow and transport models to support cleanup decisions.

  16. Evaluation of the matrix exponential for use in ground-water-flow and solute-transport simulations; theoretical framework

    Science.gov (United States)

    Umari, A.M.; Gorelick, S.M.

    1986-01-01

    It is possible to obtain analytic solutions to the groundwater flow and solute transport equations if space variables are discretized but time is left continuous. From these solutions, hydraulic head and concentration fields for any future time can be obtained without ' marching ' through intermediate time steps. This analytical approach involves matrix exponentiation and is referred to as the Matrix Exponential Time Advancement (META) method. Two algorithms are presented for the META method, one for symmetric and the other for non-symmetric exponent matrices. A numerical accuracy indicator, referred to as the matrix condition number, was defined and used to determine the maximum number of significant figures that may be lost in the META method computations. The relative computational and storage requirements of the META method with respect to the time marching method increase with the number of nodes in the discretized problem. The potential greater accuracy of the META method and the associated greater reliability through use of the matrix condition number have to be weighed against this increased relative computational and storage requirements of this approach as the number of nodes becomes large. For a particular number of nodes, the META method may be computationally more efficient than the time-marching method, depending on the size of time steps used in the latter. A numerical example illustrates application of the META method to a sample ground-water-flow problem. (Author 's abstract)

  17. Ground water and energy

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)

  18. Ground-water flow, geochemistry, and effects of agricultural practices on nitrogen transport at study sites in the Piedmont and Coastal Plain physiographic provinces, Patuxent River basin, Maryland

    Science.gov (United States)

    McFarland, Randolph E.

    1997-01-01

    In an effort to improve water quality in Chesapeake Bay, agricultural practices are being promoted that are intended to reduce contaminant transport to the Bay. The effects of agricultural practices on nitrogen transport were assessed at two 10-acre study sites in the Patuxent River basin, Maryland, during 1986-92. Nitrogen load was larger in ground water than in surface runoff at both sites. At the study site in the Piedmont Province, nitrogen load in ground water decreased from 12 to 6 (lb/acre)/yr (pound per acre per year) as corn under no-till cultivation was replaced by no-till soybeans, continuous alfalfa, and contoured strip crops alternated among corn, alfalfa, and soybeans. At the study site in the Coastal Plain Province, no-till soybeans resulted in a nitrogen load in ground water of 12.55 (lb/acre)/yr, whereas conventional-till soybeans resulted in a nitrogen load in ground water of 11.51 (lb/acre)/yr.

  19. Transport of a nematicide in surface and ground waters in a farmed tropical catchment with volcanic substratum

    Science.gov (United States)

    Charlier, J.-B.; Cattan, P.; Voltz, M.; Moussa, R.

    2009-04-01

    Assessment of water-pollution risks in agricultural regions requires studying pesticide transport processes in soil and water compartments at the catchment scale. In tropical regions, banana (Musa spp.) plantations are located in zones with abundant rainfalls and soils with high infiltration rates, which lead to washout and leaching of soil-applied pesticides, causing severe diffuse pollution of water resources. The aim of this paper is to determine how the nematicide cadusafos [S,S-di-sec-butyl O-ethyl phosphorodithioate], used in banana plantations, contaminates water and soils at the two scales of subcatchment and catchment. The study site was a small banana-growing catchment on the tropical volcanic island of Guadeloupe in the Caribbean (FWI). The catchment is located in pedoclimatic conditions where rainfall is abundant (> 4000 mm/year), and soil permeable (saturated hydraulic conductivity of Andosol Ks > 30 mm/h). Two campaigns of nematicide application were conducted, one in 2003 over 40% of the catchment and one in 2006 over 12%. For 100 days after application, we monitored the surface water and groundwater flows and the cadusafos concentrations in the soil and in surface and ground waters in a 2400 m² subcatchment and a 17.8 ha catchment. The results show that at the subcatchment scale the high retention in the A horizon of the soil limited the transport of cadusafos by runoff, whereas the lower retention of the molecule in the B horizon favoured percolation towards the shallow groundwater. The contamination levels of surface water, as well as shallow and deep groundwaters, reflected the geological structure of the Féfé catchment: i.e. a shallow aquifer in the most recent volcanic deposits that is rapidly exposed to pollution and a deeper aquifer that is relatively protected from the pollution coming from the treated fields. Comparing the losses of cadusafos at the subcatchment and at the catchment scales revealed that the nematicide re-infiltrated in

  20. Fate and transport of petroleum hydrocarbons in soil and ground water at Big South Fork National River and Recreation Area, Tennessee and Kentucky, 2002-2003

    Science.gov (United States)

    Williams, Shannon D.; Ladd, David E.; Farmer, James

    2006-01-01

    In 2002 and 2003, the U.S. Geological Survey (USGS), by agreement with the National Park Service (NPS), investigated the effects of oil and gas production operations on ground-water quality at Big South Fork National River and Recreation Area (BISO) with particular emphasis on the fate and transport of petroleum hydrocarbons in soils and ground water. During a reconnaissance of ground-water-quality conditions, samples were collected from 24 different locations (17 springs, 5 water-supply wells, 1 small stream, and 1 spring-fed pond) in and near BISO. Benzene, toluene, ethylbenzene, and xylene (BTEX) compounds were not detected in any of the water samples, indicating that no widespread contamination of ground-water resources by dissolved petroleum hydrocarbons probably exists at BISO. Additional water-quality samples were collected from three springs and two wells for more detailed analyses to obtain additional information on ambient water-quality conditions at BISO. Soil gas, soil, water, and crude oil samples were collected at three study sites in or near BISO where crude oil had been spilled or released (before 1993). Diesel range organics (DRO) were detected in soil samples from all three of the sites at concentrations greater than 2,000 milligrams per kilogram. Low concentrations (less than 10 micrograms per kilogram) of BTEX compounds were detected in lab-analyzed soil samples from two of the sites. Hydrocarbon-degrading bacteria counts in soil samples from the most contaminated areas of the sites were not greater than counts for soil samples from uncontaminated (background) sites. The elevated DRO concentrations, the presence of BTEX compounds, and the low number of -hydrocarbon-degrading bacteria in contaminated soils indicate that biodegradation of petroleum hydrocarbons in soils at these sites is incomplete. Water samples collected from the three study sites were analyzed for BTEX and DRO. Ground-water samples were collected from three small springs at the

  1. Variable thickness transient ground-water flow model. Volume 3. Program listings

    Energy Technology Data Exchange (ETDEWEB)

    Reisenauer, A.E.

    1979-12-01

    The Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program is developing and applying the methodology for assessing the far-field, long-term post-closure safety of deep geologic nuclear waste repositories. AEGIS is being performed by Pacific Northwest Laboratory (PNL) under contract with the Office of Nuclear Waste Isolation (OWNI) for the Department of Energy (DOE). One task within AEGIS is the development of methodology for analysis of the consequences (water pathway) from loss of repository containment as defined by various release scenarios. Analysis of the long-term, far-field consequences of release scenarios requires the application of numerical codes which simulate the hydrologic systems, model the transport of released radionuclides through the hydrologic systems to the biosphere, and, where applicable, assess the radiological dose to humans. Hydrologic and transport models are available at several levels of complexity or sophistication. Model selection and use are determined by the quantity and quality of input data. Model development under AEGIS and related programs provides three levels of hydrologic models, two levels of transport models, and one level of dose models (with several separate models). This is the third of 3 volumes of the description of the VTT (Variable Thickness Transient) Groundwater Hydrologic Model - second level (intermediate complexity) two-dimensional saturated groundwater flow.

  2. Evaluating the effects of urbanization and land-use planning using ground-water and surface-water models

    Science.gov (United States)

    Hunt, R.J.; Steuer, J.J.

    2001-01-01

    Why are the effects of urbanization a concern? As the city of Middleton, Wisconsin, and its surroundings continue to develop, the Pheasant Branch watershed (fig.l) is expected to undergo urbanization. For the downstream city of Middleton, urbanization in the watershed can mean increased flood peaks, water volume and pollutant loads. More subtly, it may also reduce water that sustains the ground-water system (called "recharge") and adversely affect downstream ecosystems that depend on ground water such as the Pheasant Branch Springs (hereafter referred to as the Springs). The relation of stormwater runoff and reduced ground-water recharge is complex because the surface-water system is coupled to the underlying ground-water system. In many cases there is movement of water from one system to the other that varies seasonally or daily depending on changing conditions. Therefore, it is difficult to reliably determine the effects of urbanization on stream baseflow and spring flows without rigorous investigation. Moreover, mitigating adverse effects after development has occurred can be expensive and administratively difficult. Overlying these concerns are issues such as stewardship of the resource, the rights of the public, and land owners' rights both of those developing their land and those whose land is affected by this development. With the often- contradictory goals, a scientific basis for assessing effects of urbanization and effectiveness of mitigation measures helps ensure fair and constructive decision-making. The U.S. Geological Survey, in cooperation with the City of Middleton and Wisconsin Department of Natural Resources, completed a study that helps address these issues through modeling of the hydrologic system. This Fact Sheet discusses the results of this work.

  3. Ground-water flow and contaminant transport at a radioactive-materials processing site, Wood River Junction, Rhode Island

    Science.gov (United States)

    Ryan, Barbara J.; Kipp, Kenneth L.

    1997-01-01

    Liquid wastes from an enriched-uranium cold-scrap recovery plant at Wood River Junction, Rhode Island, were discharged to the environment through evaporation ponds and trenches from 1966 through 1980. Leakage from the ponds and trenches resulted in a plume of contaminated ground water extending northwestward to the Pawcatuck River through a highly permeable sand and gravel aquifer of glacial origin.

  4. A three-dimensional numerical model of predevelopment conditions in the Death Valley regional ground-water flow system, Nevada and California

    Science.gov (United States)

    D'Agnese, Frank A.; O'Brien, G. M.; Faunt, C.C.; Belcher, W.R.; San Juan, C.

    2002-01-01

    In the early 1990's, two numerical models of the Death Valley regional ground-water flow system were developed by the U.S. Department of Energy. In general, the two models were based on the same basic hydrogeologic data set. In 1998, the U.S. Department of Energy requested that the U.S. Geological Survey develop and maintain a ground-water flow model of the Death Valley region in support of U.S. Department of Energy programs at the Nevada Test Site. The purpose of developing this 'second-generation' regional model was to enhance the knowledge an understanding of the ground-water flow system as new information and tools are developed. The U.S. Geological Survey also was encouraged by the U.S. Department of Energy to cooperate to the fullest extent with other Federal, State, and local entities in the region to take advantage of the benefits of their knowledge and expertise. The short-term objective of the Death Valley regional ground-water flow system project was to develop a steady-state representation of the predevelopment conditions of the ground-water flow system utilizing the two geologic interpretations used to develop the previous numerical models. The long-term objective of this project was to construct and calibrate a transient model that simulates the ground-water conditions of the study area over the historical record that utilizes a newly interpreted hydrogeologic conceptual model. This report describes the result of the predevelopment steady-state model construction and calibration. The Death Valley regional ground-water flow system is situated within the southern Great Basin, a subprovince of the Basin and Range physiographic province, bounded by latitudes 35 degrees north and 38 degrees 15 minutes north and by longitudes 115 and 118 degrees west. Hydrology in the region is a result of both the arid climatic conditions and the complex geology. Ground-water flow generally can be described as dominated by interbasinal flow and may be conceptualized as

  5. Ground-Water Flow Model of the Sierra Vista Subwatershed and Sonoran Portions of the Upper San Pedro Basin, Southeastern Arizona, United States, and Northern Sonora, Mexico

    Science.gov (United States)

    Pool, D.R.; Dickinson, Jesse E.

    2007-01-01

    A numerical ground-water model was developed to simulate seasonal and long-term variations in ground-water flow in the Sierra Vista subwatershed, Arizona, United States, and Sonora, Mexico, portions of the Upper San Pedro Basin. This model includes the simulation of details of the groundwater flow system that were not simulated by previous models, such as ground-water flow in the sedimentary rocks that surround and underlie the alluvial basin deposits, withdrawals for dewatering purposes at the Tombstone mine, discharge to springs in the Huachuca Mountains, thick low-permeability intervals of silt and clay that separate the ground-water flow system into deep-confined and shallow-unconfined systems, ephemeral-channel recharge, and seasonal variations in ground-water discharge by wells and evapotranspiration. Steady-state and transient conditions during 1902-2003 were simulated by using a five-layer numerical ground- water flow model representing multiple hydrogeologic units. Hydraulic properties of model layers, streamflow, and evapotranspiration rates were estimated as part of the calibration process by using observed water levels, vertical hydraulic gradients, streamflow, and estimated evapotranspiration rates as constraints. Simulations approximate observed water-level trends throughout most of the model area and streamflow trends at the Charleston streamflow-gaging station on the San Pedro River. Differences in observed and simulated water levels, streamflow, and evapotranspiration could be reduced through simulation of climate-related variations in recharge rates and recharge from flood-flow infiltration.

  6. The use of hydrological and geoelectrical data to fix the boundary conditions of a ground water flow model: a case study

    Directory of Open Access Journals (Sweden)

    M. Giudici

    2003-01-01

    Full Text Available To assess whether the hydrometric level of an artificial lake in a quarry near Milan (Italy could be assigned as a Dirichlet boundary condition for the phreatic aquifer in a fine scale groundwater flow model, hydrological measurements of piezometric head and rainfall rate time series have been analysed by spectral and statistical methods. The piezometric head close to the quarry lake proved to be well correlated with seasonal variations in the rainfall. Furthermore, geoelectrical tomography detected no semi-permeable layer between the phreatic aquifer and the lake, so the contact between surface and ground water is good. Finally, a time-varying prescribed head condition can be applied for ground water flow modelling. Keywords: ground water flow, boundary conditions, surface and ground water interactions, geoelectrical tomography, statistical analysis.

  7. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  8. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  9. Assessment of Effectiveness of Geologic Isolation Systems. Variable thickness transient ground-water flow model. Volume 2. Users' manual

    Energy Technology Data Exchange (ETDEWEB)

    Reisenauer, A.E.

    1979-12-01

    A system of computer codes to aid in the preparation and evaluation of ground-water model input, as well as in the computer codes and auxillary programs developed and adapted for use in modeling major ground-water aquifers is described. The ground-water model is interactive, rather than a batch-type model. Interactive models have been demonstrated to be superior to batch in the ground-water field. For example, looking through reams of numerical lists can be avoided with the much superior graphical output forms or summary type numerical output. The system of computer codes permits the flexibility to develop rapidly the model-required data files from engineering data and geologic maps, as well as efficiently manipulating the voluminous data generated. Central to these codes is the Ground-water Model, which given the boundary value problem, produces either the steady-state or transient time plane solutions. A sizeable part of the codes available provide rapid evaluation of the results. Besides contouring the new water potentials, the model allows graphical review of streamlines of flow, travel times, and detailed comparisons of surfaces or points at designated wells. Use of the graphics scopes provide immediate, but temporary displays which can be used for evaluation of input and output and which can be reproduced easily on hard copy devices, such as a line printer, Calcomp plotter and image photographs.

  10. Locations, values, and uncertainties of hydraulic-head observations for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set contains the locations, values, and uncertainties of hydraulic-head observations used in the calibration of the transient model of...

  11. Locations, values, and uncertainties of hydraulic-head observations for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set contains the locations, values, and uncertainties of hydraulic-head observations used in the calibration of the transient model of...

  12. Interactions between surface water and ground water and effects on mercury transport in the north-central Everglades

    Science.gov (United States)

    Harvey, Judson W.; Krupa, Steven L.; Gefvert, Cynthia; Mooney, Robert H.; Choi, Jungyill; King, Susan A.; Giddings, Jefferson B.

    2002-01-01

    The hydrology of the north-central Everglades was altered substantially in the past century by canal dredging, land subsidence, ground-water pumping, and levee construction. Vast areas of seasonal and perennial wetlands were converted to uses for agriculture, light industry, and suburban development. As the catchment area for the Everglades decreased, so did the sources of water from local precipitation and runoff from surrounding uplands. Partly in response to those alterations, water-resources managers compartmentalized the remaining wetlands in the north-central Everglades into large retention basins, called Water Conservation Areas (WCAs). In spite of efforts to improve how water resources are managed, the result has been frequent periods of excessive drying out or flooding of the WCAs because the managed system does not have the same water-storage capacity as the pre-drainage Everglades. Linked to the hydrological modifications are ecological changes including large-scale invasions of cattail, loss of tree islands, and diminishing bird populations in the Everglades. Complex interactions among numerous physical, chemical, and biological factors are responsible for the long-term degradation of the ecological character of the Everglades.Over the past 15 years, a new set of smaller wetland basins, called Stormwater Treatment Areas (STAs), have been designed and constructed by water-resources engineers on the former wetlands adjacent to WCAs. The purpose of STAs is to remove excess nutrients from agricultural drainage water prior to its input to WCAs. STAs tend to be about one-tenth the size of a WCA, and they are located on former wetlands on the northwestern side of WCAs on sites that were managed as farmland for much of the twentieth century in an area referred to as the Everglades Agricultural Area, or EAA. The objective of the present investigation was to quantify interactions between surface water and ground water in the Everglades Nutrient Removal Project

  13. A three-dimensional numerical model of predevelopment conditions in the Death Valley regional ground-water flow system, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    D' Agnese, F.A.; O' Brien, G.M.; Faunt, C.C.; Belcher, W.R.; San Juan, Carma

    2002-11-22

    In the early 1990's, two numerical models of the Death Valley regional ground-water flow system were developed by the U.S. Department of Energy. In general, the two models were based on the same basic hydrogeologic data set. In 1998, the U.S. Department of Energy requested that the U.S. Geological Survey develop and maintain a ground-water flow model of the Death Valley region in support of U.S. Department of Energy programs at the Nevada Test Site. The purpose of developing this ''second-generation'' regional model was to enhance the knowledge and understanding of the ground-water flow system as new information and tools are developed. The U.S. Geological Survey also was encouraged by the U.S. Department of Energy to cooperate to the fullest extent with other Federal, State, and local entities in the region to take advantage of the benefits of their knowledge and expertise. The short-term objective of the Death Valley regional ground-water flow system project was to develop a steady-stat e representation of the predevelopment conditions of the ground-water flow system utilizing the two geologic interpretations used to develop the previous numerical models. The long-term objective of this project was to construct and calibrate a transient model that simulates the ground-water conditions of the study area over the historical record that utilizes a newly interpreted hydrogeologic conceptual model. This report describes the result of the predevelopment steady-state model construction and calibration.

  14. Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in shallow, recently recharged ground water -- Model output data set (gwava-s_out)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents predicted nitrate concentration in shallow, recently recharged ground water, in milligrams per liter, in the conterminous United States, and...

  15. Investigation of the behavior of VOCs in ground water across fine- and coarse-grained geological contacts using a medium-scale physical model

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, F.; Chiarappa, M.L.

    1998-03-01

    One of the serious impediments to the remediation of ground water contaminated with volatile organic compounds (VOCs) is that the VOCs are retarded with respect to the movement of the ground water. Although the processes that result in VOC retardation are poorly understood, we have developed a conceptual model that includes several retarding mechanisms. These include adsorption to inorganic surfaces, absorption to organic carbon, and diffusion into areas of immobile waters. This project was designed to evaluate the relative contributions of these mechanisms; by improving our understanding, we hope to inspire new remediation technologies or approaches. Our project consisted of a series of column experiments designed to measure the retardation, in different geological media, of four common ground water VOCs (chloroform, carbon tetrachloride, trichloroethylene, and tetrachloroethylene) which have differing physical and chemical characteristics. It also included a series of diffusion parameters that constrain the model, we compared the data from these experiments to the output of a computational model.

  16. Organic Wastewater Compounds, Pharmaceuticals, andColiphage in Ground Water Receiving Discharge from OnsiteWastewater Treatment Systems near La Pine, Oregon:Occurrence and Implications for Transport

    Science.gov (United States)

    Hinkle, Stephen J.; Weick, Rodney J.; Johnson, Jill M.; Cahill, Jeffery D.; Smith, Steven G.; Rich, Barbara J.

    2005-01-01

    The occurrence of organic wastewater compounds (components of 'personal care products' and other common household chemicals), pharmaceuticals (human prescription and nonprescription medical drugs), and coliphage (viruses that infect coliform bacteria, and found in high concentrations in municipal wastewater) in onsite wastewater (septic tank effluent) and in a shallow, unconfined, sandy aquifer that serves as the primary source of drinking water for most residents near La Pine, Oregon, was documented. Samples from two types of observation networks provided basic occurrence data for onsite wastewater and downgradient ground water. One observation network was a group of 28 traditional and innovative (advanced treatment) onsite wastewater treatment systems and associated downgradient drainfield monitoring wells, referred to as the 'innovative systems network'. The drainfield monitoring wells were located adjacent to or under onsite wastewater treatment system drainfield lines. Another observation network, termed the 'transect network', consisted of 31 wells distributed among three transects of temporary, stainless-steel-screened, direct-push monitoring wells installed along three plumes of onsite wastewater. The transect network, by virtue of its design, also provided a basis for increased understanding of the transport of analytes in natural systems. Coliphage were frequently detected in onsite wastewater. Coliphage concentrations in onsite wastewater were highly variable, ranging from less than 1 to 3,000,000 plaque forming units per 100 milliliters. Coliphage were occasionally detected (eight occurrences) at low concentrations in samples from wells located downgradient from onsite wastewater treatment system drainfield lines. However, coliphage concentrations were below method detection limits in replicate or repeat samples collected from the eight sites. The consistent absence of coliphage detections in the replicate or repeat samples is interpreted to indicate

  17. Transport and fate of nitrate in a glacial outwash aquifer in relation to ground water age, land use practices, and redox processes

    Science.gov (United States)

    Puckett, L.J.; Cowdery, T.K.

    2002-01-01

    A combination of ground water modeling, chemical and dissolved gas analyses, and chlorofluorocarbon age dating of water was used to determine the relation between changes in agricultural practices, and NO3- concentrations in ground water of a glacial outwash aquifer in west-central Minnesota. The results revealed a redox zonation throughout the saturated zone with oxygen reduction occurring near the water table, NO3- reduction immediately below it, and then a large zone of ferric iron reduction, with a small area of sulfate (SO42-) reduction and methanogenesis (CH4) near the end of the transect. Analytical and NETPATH modeling results supported the hypothesis that organic carbon served as the electron donor for the redox reactions. Denitrification rates were quite small, 0.005 to 0.047 mmol NO3- yr-1, and were limited by the small amounts of organic carbon, 0.01 to 1.45%. In spite of the organic carbon limitation, denitrification was virtually complete because residence time is sufficient to allow even slow processes to reach completion. Ground water sample ages showed that maximum residence times were on the order of 50 to 70 yr. Reconstructed NO3- concentrations, estimated from measured NO3- and dissolved N gas showed that NO3- concentrations have been increasing in the aquifer since the 1940s, and have been above the 714 ??mol L-1 maximum contaminant level at most sites since the mid- to late-1960s. This increase in NO3- has been accompanied by a corresponding increase in agricultural use of fertilizer, identified as the major source of NO3- to the aquifer.

  18. Documenting Ground-Water Modeling at Sites Contaminated with Radioactive Substances

    Science.gov (United States)

    This report is the product of the Interagency Environmental Pathway Modeling Working Group. This report demonstrates how to document model applications in a consistent manner and is intended to assist technical staff.

  19. Ground water in Oklahoma

    Science.gov (United States)

    Leonard, A.R.

    1960-01-01

    One of the first requisites for the intelligent planning of utilization and control of water and for the administration of laws relating to its use is data on the quantity, quality, and mode of occurrence of the available supplies. The collection, evaluation and interpretation, and publication of such data are among the primary functions of the U.S. Geological Survey. Since 1895 the Congress has made appropriations to the Survey for investigation of the water resources of the Nation. In 1929 the Congress adopted the policy of dollar-for-dollar cooperation with the States and local governmental agencies in water-resources investigations of the U.S. Geological Survey. In 1937 a program of ground-water investigations was started in cooperation with the Oklahoma Geological Survey, and in 1949 this program was expanded to include cooperation with the Oklahoma Planning and Resources Board. In 1957 the State Legislature created the Oklahoma Water Resources Board as the principal State water agency and it became the principal local cooperator. The Ground Water Branch of the U.S. Geological Survey collects, analyzes, and evaluates basic information on ground-water resources and prepares interpretive reports based on those data. Cooperative ground-water work was first concentrated in the Panhandle counties. During World War II most work was related to problems of water supply for defense requirements. Since 1945 detailed investigations of ground-water availability have been made in 11 areas, chiefly in the western and central parts of the State. In addition, water levels in more than 300 wells are measured periodically, principally in the western half of the State. In Oklahoma current studies are directed toward determining the source, occurrence, and availability of ground water and toward estimating the quantity of water and rate of replenishment to specific areas and water-bearing formations. Ground water plays an important role in the economy of the State. It is

  20. Recalibration of a ground-water flow model of the Mississippi River Valley alluvial aquifer of northeastern Arkansas, 1918-1998, with simulations of water levels caused by projected ground-water withdrawals through 2049

    Science.gov (United States)

    Reed, Thomas B.

    2003-01-01

    A digital model of the Mississippi River Valley alluvial aquifer in eastern Arkansas was used to simulate ground-water flow for the period from 1918 to 2049. The model results were used to evaluate effects on water levels caused by demand for ground water from the alluvial aquifer, which has increased steadily for the last 40 years. The model results showed that water currently (1998) is being withdrawn from the aquifer at rates greater than what can be sustained for the long term. The saturated thickness of the alluvial aquifer has been reduced in some areas resulting in dry wells, degraded water quality, decreased water availability, increased pumping costs, and lower well yields. The model simulated the aquifer from a line just north of the Arkansas-Missouri border to south of the Arkansas River and on the east from the Mississippi River westward to the less permeable geologic units of Paleozoic age. The model consists of 2 layers, a grid of 184 rows by 156 columns, and comprises 14,118 active cells each measuring 1 mile on a side. It simulates time periods from 1918 to 1998 along with further time periods to 2049 testing different pumping scenarios. Model flux boundary conditions were specified for rivers, general head boundaries along parts of the western side of the model and parts of Crowleys Ridge, and a specified head boundary across the aquifer further north in Missouri. Model calibration was conducted for observed water levels for the years 1972, 1982, 1992, and 1998. The average absolute residual was 4.69 feet and the root-mean square error was 6.04 feet for the hydraulic head observations for 1998. Hydraulic-conductivity values obtained during the calibration process were 230 feet per day for the upper layer and ranged from 230 to 730 feet per day for the lower layer with the maximum mean for the combined aquifer of 480 feet per day. Specific yield values were 0.30 throughout the model and specific storage values were 0.000001 inverse-feet throughout

  1. Hydrogeologic controls on ground-water and contaminant discharge to the Columbia River near the Hanford Townsite

    Energy Technology Data Exchange (ETDEWEB)

    Luttrell, S.P.; Newcomer, D.R.; Teel, S.S.; Vermeul, V.R.

    1992-11-01

    The purpose of this study is to quantify ground-water and contaminant discharge to the Columbia River in the Hanford Townsite vicinity. The primary objectives of the work are to: describe the hydrogeologic setting and controls on ground-water movement and contaminant discharge to the Columbia River; understand the river/aquifer relationship and its effects on contaminant discharge to the Columbia River; quantify the ground-water and contaminant mass discharge to the Columbia River; and provide data that may be useful for a three-dimensional model of ground-water flow and contaminant transport in the Hanford Townsite study area. The majority of ground-water contamination occurs within the unconfined aquifer; therefore, ground-water and contaminant discharge from the unconfined aquifer is the emphasis of this study. The period of study is primarily from June 1990 through March 1992.

  2. Hanford Site ground-water monitoring for July through December 1987

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Dennison, D.I.; Bryce, R.W.; Mitchell, P.J.; Sherwood, D.R.; Krupka, K.M.; Hinman, N.W.; Jacobson, E.A.; Freshley, M.D.

    1988-12-01

    The Pacific Northwest Laboratory monitors ground-water quality at the Hanford Site for the US Department of Energy to assess the impact of Site operations on the environment. Work undertaken between July and December 1987 included monitoring ground-water elevations across the Site, monitoring hazardous chemicals and radionuclides in ground water, geochemical evaluations of unconfined ground-water data, and calibration of ground-water flow and transport models. Water levels continued to rise in areas receiving increased recharge (e.g., beneath B Pond) and decline in areas where the release of water to disposal facilities has been terminated (e.g., U Pond). The major areas of ground-water contamination defined by monitoring activities are (1) carbon tetrachloride in the 200-West Area; (2) cyanide in and north of the 200-East and 200-West Areas; (3) hexavalent chromium contamination in the 100-B, 100-D, 100-F, 100-H, 100-K, and 200-West Areas; (4) chlorinated hydrocarbons in the vicinity of the Central Landfill and 300 Area; (5) uranium in the 100-F, 100-H, 200-West, and 300 Areas; and (6) tritium and nitrate across the Site. The MINTEQ geochemical code was used to identify chemical reactions that may be affecting the concentrations of dissolved hazardous chemicals in the unconfined ground water. Results indicate that many cations are present mainly as dissolved carbonate complexes and that a majority of the ground-water samples are in near equilibrium with carbonate minerals (e.g., calcite, dolomite, otavite).

  3. Forward Modeling and validation of a new formulation to compute self-potential signals associated with ground water flow

    Directory of Open Access Journals (Sweden)

    A. Bolève

    2007-10-01

    Full Text Available The classical formulation of the coupled hydroelectrical flow in porous media is based on a linear formulation of two coupled constitutive equations for the electrical current density and the seepage velocity of the water phase and obeying Onsager's reciprocity. This formulation shows that the streaming current density is controlled by the gradient of the fluid pressure of the water phase and a streaming current coupling coefficient that depends on the so-called zeta potential. Recently a new formulation has been introduced in which the streaming current density is directly connected to the seepage velocity of the water phase and to the excess of electrical charge per unit pore volume in the porous material. The advantages of this formulation are numerous. First this new formulation is more intuitive not only in terms of establishing a constitutive equation for the generalized Ohm's law but also in specifying boundary conditions for the influence of the flow field upon the streaming potential. With the new formulation, the streaming potential coupling coefficient shows a decrease of its magnitude with permeability in agreement with published results. The new formulation has been extended in the inertial laminar flow regime and to unsaturated conditions with applications to the vadose zone. This formulation is suitable to model self-potential signals in the field. We investigate infiltration of water from an agricultural ditch, vertical infiltration of water into a sinkhole, and preferential horizontal flow of ground water in a paleochannel. For the three cases reported in the present study, a good match is obtained between finite element simulations performed and field observations. Thus, this formulation could be useful for the inverse mapping of the geometry of groundwater flow from self-potential field measurements.

  4. Submarine ground-water discharge: nutrient loading and nitrogen transformations

    Science.gov (United States)

    Kroeger, Kevin D.; Swarzenski, Peter W.; Crusius, John; Bratton, John F.; Charette, Matthew A.

    2006-01-01

    Eutrophication of coastal waters due to nonpoint source land-derived nitrogen (N) loads is a worldwide phenomenon and perhaps the greatest agent of change altering coastal ecology (National Research Council, 2000; Howarth and others, 2000). Within the United States, a majority of estuaries have been determined to be moderately to severely impaired by eutrophication associated with increasing nutrient loads (Bricker and others, 1999).In coastal watersheds with soils of high hydraulic conductivity and permeable coastal sediments, ground water is a major route of transport of freshwater and its solutes from land to sea. Freshwater flowing downgradient from aquifers may either discharge from a seepage face near the intertidal zone, or flow directly into the sea as submarine ground-water discharge (SGD) (fig. 1). In the coastal aquifer, entrainment of saline pore water occurs prior to discharge, producing a gradient in ground-water salinity from land to sea, referred to as a subterranean estuary (Moore, 1999). In addition, processes including density-driven flow and tidal pumping create brackish and saline ground-water circulation. Hence, submarine ground-water discharge often consists of a substantial amount of recirculating seawater. Mixing of fresh and saline ground waters in the context of coastal sediments may alter the chemical composition of the discharging fluid. Depending on the biogeochemical setting, removal of fixed N due to processes leading to N2 (dinitrogen gas) production in the nearshore aquifer and subterranean estuary may significantly attenuate land-derived N loads; or, processes such as ion exchange and tidal pumping in the subterranean estuary may substantially accelerate the transport of both land-derived and sediment re-mineralized N to estuarine water columns.As emphasized by Burnett and others (2001, 2002), a fundamental problem in evaluating the importance of ground-water discharge in marine geochemical budgets is the difficulty of collecting

  5. Simulation of cylindrical flow to a well using the U.S. Geological Survey Modular Finite-Difference Ground-Water Flow Model

    Science.gov (United States)

    Reilly, Thomas E.; Harbaugh, Arlen W.

    1993-01-01

    Cylindrical (axisymmetric) flow to a well is an important specialized topic of ground-water hydraulics and has been applied by many investigators to determine aquifer properties and determine heads and flows in the vicinity of the well. A recent modification to the U.S. Geological Survey Modular Three-Dimensional Finite-Difference Ground-Water Flow Model provides the opportunity to simulate axisymmetric flow to a well. The theory involves the conceptualization of a system of concentric shells that are capable of reproducing the large variations in gradient in the vicinity of the well by decreasing their area in the direction of the well. The computer program presented serves as a preprocessor to the U.S. Geological Survey model by creating the input data file needed to implement the axisymmetric conceptualization. Data input requirements to this preprocessor are described, and a comparison with a known analytical solution indicates that the model functions appropriately.

  6. Identifying the hotspots of non-renewable water use using HiGW-MAT: A new land surface model coupled with human interventions and ground water reservoir

    Science.gov (United States)

    Oki, T.; Pokhrel, Y. N.; Yeh, P. J.; Koirala, S.; Kanae, S.; Hanasaki, N.

    2011-12-01

    The real hydrological cycles on the Earth are not natural anymore. Global hydrological model simulations of the water cycle and available water resources should have an ability to consider the effects of human interventions on hydrological cycles. Anthropogenic activity modules (Hanasaki et al., 2008), such as reservoir operation, crop growth and water demand in crop lands, and environmental flows, were incorporated into a land surface model called MATSIRO (Takata et al., 2003), to form a new model, MAT-HI (Pokhrel et al., 2011). Total terrestrial water storages (TWS) in large river basins were estimated using the new model by off-line simulation, and compared with the TWS observed by GRACE for 2002-2007. The results showed MAT-HI has an advantage estimating TWS particularly in arid river basins compared with H08 (Hanasaki et al., 2008). MAT-HI was further coupled with a module representing the ground water level fluctuations (Yeh et al., 2005), and consists a new land surface scheme HiGW-MAT (Human Intervention and Ground Water coupled MATSIRO). HiGW-MAT is also associated with a scheme tracing the origin and flow path with the consideration on the sources of water withdrawal from stream flow, medium-size reservoirs and nonrenewable groundwater in addition to precipitation to croplands enabled the assessment of the origin of water producing major crops as Hanasaki et al. (2010). Areas highly dependent on nonrenewable groundwater are detected in the Pakistan, Bangladesh, western part of India, north and western parts of China, some regions in the Arabian Peninsula and the western part of the United States through Mexico. Cumulative nonrenewable groundwater withdrawals estimated by the model are corresponding fairly well with the country statistics of total groundwater withdrawals. Ground water table depletions in large aquifers in US estimated by HiGW-MAT were compared with in-situ observational data, and the correspondences are very good. Mean global exploitation

  7. Simulative models for the analysis of ground-water flow in Vekol Valley, the Waterman Wash area, and the Bosque area, Maricopa and Pina counties, Arizona

    Science.gov (United States)

    Matlock, D.T.

    1981-01-01

    Simulative ground-water flow models for Vekol Valley, the Waterman Wash area, and the Bosque area were developed for use in evaluating alternatives for developing a ground-water supply for the Ak-Chin Indian Community. The hydraulic properties of the basin-fill deposits used in the models were estimated primarily from aquifer tests made by the U.S. Geological Survey. Annual recharge to Vekol Valley and the Waterman Wash area is negligible in comparison to the quantity of water in storage and the quantity proposed to be pumped. The models are based on a three-dimensional, block-centered, finite-difference scheme. The Vekol Valley model was calibrated for steady-state onditions, and the Waterman Wash area model was calibrated for steady-state and transient conditions. The sensitivity of calibrated heads to changes in transmissivity was also investigated. An uncalibrated storage-depletion model was developed for the Bosque area. Simulated water levels for steady-state conditions average within 5 feet of measured values for Vekoi Valley and within 6 feet for the Waterman Wash area. Simulated water levels for transient conditions in the Waterman Wash area average within 8 feet of measured values for 15 years of analysis and within 15 feet for 24 years. Water-level declines simulated by the Waterman Wash area model average within 17 feet of those measured during the 24-year period, 1951-75.

  8. ITE CHARACTERIZATION TO SUPPORT CONCEPTUAL MODEL DEVELOPMENT FOR SUBSURFACE RADIONUCLIDE TRANSPORT

    Science.gov (United States)

    Remediation of radionuclide contaminants in ground water often begins with the development of conceptual and analytical models that guide our understanding of the processes controlling radionuclide transport. The reliability of these models is often predicated on the collection o...

  9. Potential development and recharge of ground water in Mill Creek Valley, Butler and Hamilton Counties, Ohio, based on analog model analysis

    Science.gov (United States)

    Fidler, Richard E.

    1971-01-01

    Mill Creek valley is part of the greater Cincinnati industrial area in southwestern Ohio. In 1964, nearly 30 percent of the water supply in the study area of about 27 square miles was obtained from wells in the glacial-outwash aquifer underlying the valley. Ground-water demand has increased steadily since the late 1800's, and excessive pumpage during the years of World War II caused water levels to decline to critical levels. Natural recharge to the aquifer, from precipitation, is about 8.5 mgd (million gallons per day). In 1964, the total water use was about 30 mgd, of which 8.1 mgd was obtained from wells in Mill Creek valley, and the remainder was imported from outside the basin. With rapid industrial expansion and population growth, demand for ground water is continuing to increase. By the year 2000 ground-water pumpage is expected to exceed 25 mgd. At a public hearing before the Ohio Water Commission in 1961, artificial recharge of the aquifer through injection wells was proposed as a possible solution to the Mill Creek valley water-supply problem. The present study attempts to determine the feasibility of injection-well recharge systems in the Mill Creek valley. Although basically simple, the hydrologic system in Mill Creek valley is complex in detail and is difficult to evaluate using conventional quantitative methods. Because of this complexity, an electric analog model was used to test specific development plans. Three hypothetical pumping plans were developed by projecting past pumpage data to the years 1980 and 2000. Various combinations of injection wells were tested on the model under different hypothetical conditions of pumpage. Based on analog model analysis, from three to eight inject-ion wells, with an approximate input of 2 mgd each, would reverse the trend in declining groundwater levels and provide adequate water to meet anticipated future demands.

  10. Ground water and climate change

    NARCIS (Netherlands)

    Taylor, R.G.; Scanlon, B.; Döll, P.; Rodell, M.; Beek, R. van; Wada, Y.; Longuevergne, L.; Leblanc, M.; Famiglietti, J.S.; Edmunds, M.; Konikow, L.; Green, T.R.; Chen, J.; Taniguchi, M.; Bierkens, M.F.P.; MacDonald, A.; Fan, Y.; Maxwell, R.M.; Yechieli, Y.; Gurdak, J.J.; Allen, D.M.; Shamsudduha, M.; Hiscock, K.; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world’s largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate chang

  11. Ground water and climate change

    NARCIS (Netherlands)

    Taylor, R.G.; Scanlon, B.; Döll, P.; Rodell, M.; Beek, R. van; Wada, Y.; Longuevergne, L.; Leblanc, M.; Famiglietti, J.S.; Edmunds, M.; Konikow, L.; Green, T.R.; Chen, J.; Taniguchi, M.; Bierkens, M.F.P.; MacDonald, A.; Fan, Y.; Maxwell, R.M.; Yechieli, Y.; Gurdak, J.J.; Allen, D.M.; Shamsudduha, M.; Hiscock, K.; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world’s largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate

  12. A ground-water model of the upper San Pedro Basin from the Mexico-United States International Boundary to Fairbank, Arizona

    Science.gov (United States)

    Freethey, G.W.

    1982-01-01

    A definition of the hydrologic system of the upper San Pedro basin was obtained by developing a numerical ground-water model to evaluate a conceptual model of the system. Information on hydraulic properties of the basin fill, recharge from bordering mountain ranges, discharge by evapotranspiration, and exchange of water between aquifer and stream was available from previous measurements or estimates. The steady-state calibration procedure and subsequent transient simulations demonstrated that the original conceptualization can be reasonably simulated. An analysis of model sensitivity to increases and decreases in certain hydraulic properties indicated a low sensitivity to aquifer anisotropy and a low to moderate sensitivity to stream leakance and evapotranspiration rate. An analysis to investigate the effects of generalizing aquifer conductivity and recharge showed that flow components and water-level response to stress could be simulated adequately but that steady-state water-level conditions could not. During equilibrium conditions, recharge to and discharge from the basin was about 16,500 acre-feet per year. Modeling results indicated that by 1978 the storage depletion rate had reached 5,600 acre-feet per year resulting from a ground-water withdrawal rate of 10,500 acre-feet per year. (USGS)

  13. General database for ground water site information.

    Science.gov (United States)

    de Dreuzy, Jean-Raynald; Bodin, Jacques; Le Grand, Hervé; Davy, Philippe; Boulanger, Damien; Battais, Annick; Bour, Olivier; Gouze, Philippe; Porel, Gilles

    2006-01-01

    In most cases, analysis and modeling of flow and transport dynamics in ground water systems require long-term, high-quality, and multisource data sets. This paper discusses the structure of a multisite database (the H+ database) developed within the scope of the ERO program (French Environmental Research Observatory, http://www.ore.fr). The database provides an interface between field experimentalists and modelers, which can be used on a daily basis. The database structure enables the storage of a large number of data and data types collected from a given site or multiple-site network. The database is well suited to the integration, backup, and retrieval of data for flow and transport modeling in heterogeneous aquifers. It relies on the definition of standards and uses a templated structure, such that any type of geolocalized data obtained from wells, hydrological stations, and meteorological stations can be handled. New types of platforms other than wells, hydrological stations, and meteorological stations, and new types of experiments and/or parameters could easily be added without modifying the database structure. Thus, we propose that the database structure could be used as a template for designing databases for complex sites. An example application is the H+ database, which gathers data collected from a network of hydrogeological sites associated with the French Environmental Research Observatory.

  14. Environmental Pathway Models-Ground-Water Modeling in Support of Remedial Decision Making at Sites Contaminated with Radioactive Material

    Science.gov (United States)

    The Joint Interagency Environmental Pathway Modeling Working Group wrote this report to promote appropriate and consistent use of mathematical environmental models in the remediation and restoration of sites contaminated by radioactive substances.

  15. Predicted effects on ground water of construction of Divide Cut section, Tennessee-Tombigbee Waterway, northeastern Mississippi, using a digital model

    Science.gov (United States)

    McBride, Mark S.

    1981-01-01

    The Tennessee-Tombigbee Waterway, connecting the Tennessee River in northeastern Mississippi with the Gulf of Mexico, is currently (1980) under construction. The Divide Section, the northernmost 39 miles of the Waterway, will consist, from north to south, of (1) a dredged channel, (2) the Divide Cut, and (3) an artifical lake impounded by the Bay Springs Dam. In all three , water will be at Tennessee River level. A three-dimensional digital model covering 3,273 square miles was constructed to simulate ground-water flow in the Gordo and Eutaw Formations and the Coffee Sand in the vicinity of the Divide Section. The model was calibrated to preconstruction water levels, then used to simulate the effects of stresses imposed by the construction of the Divide Section. The model indicates that the system stabilizes after major changes in conditions within a few months. The Divide Cut acts as a drain, lowering water levels as much as 55 feet. Drawdowns of 5 feet occur as much as 8 miles from the Cut. The 80-foot-high Bay Springs Dam raises ground-water levels by 5 feet as far as 6 miles from its impoundment. Drawdown is not likely to affect public water supplies significantly, but probably will adversely affect a relatively small number of private wells. (USGS)

  16. Ground Water Flow No Longer A Mystery

    Science.gov (United States)

    Lehr, Jay H.; Pettyjohn, Wayne A.

    1976-01-01

    Examined are the physical characteristics of ground water movement. Some potential pollution problems are identified. Models are used to explain mathematical and hydraulic principles of flow toward a pumping well and an effluent stream, flow around and through lenticular beds, and effects of pumping on the water table. (Author/MR)

  17. Ground water and climate change

    Science.gov (United States)

    Taylor, Richard G.; Scanlon, Bridget; Döll, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F.P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  18. Ground water and climate change

    Science.gov (United States)

    Taylor, Richard G.; Scanlon, Bridget; Döll, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F. P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2013-04-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  19. Ground Water and Climate Change

    Science.gov (United States)

    Taylor, Richard G.; Scanlon, Bridget; Doell, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F. P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J. -F; Holman, Ian; Treidel, Holger

    2013-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  20. Ground-Water-Flow Modeling of a Freshwater and Brine-Filled Aquifer in the Onondaga Trough, Onondaga County, New York - A Summary of Findings

    Science.gov (United States)

    Kappel, William M.; Yager, Richard M.

    2008-01-01

    In 2007, the U.S. Geological Survey (USGS) completed a hydrogeologic study that included the development of a groundwater-flow model of the glacial-drift aquifer in the Onondaga Trough near Syracuse, N.Y., which extends from the Valley Heads Moraine near Tully, N.Y., to Onondaga Lake (fig. 1). Glacial sediments within the Onondaga Trough contain freshwater, saline water, and brine, which has historically supported several chemical industries in Syracuse. The ground-water-flow model was developed as a means to assist the members of the Onondaga Lake Partnership (local, State, and Federal governmental agencies) to assess remediation plans for Onondaga Lake and the Onondaga Creek watershed. Prior to this study, in the late 1990s, very little information was known about the physical nature of the valley-fill aquifer or the quality of water within it. Acquisition of this information would help local agencies understand the interactions of fresh and saline water within the aquifer and Onondaga Lake, and would facilitate the design of proposed and ongoing remediation work in and near the lake. The USGS study characterized the geology and geochemistry of the aquifer system, estimated the rate and direction of ground-water movement, and estimated mass loadings of chloride to Onondaga Lake and its tributaries from natural and anthropogenic sources. The study required analysis of existing hydrogeologic data and drilling of new test wells to collect additional hydrogeologic data to supplement this database. A three-dimensional geologic model of the unconsolidated deposits that fill the Onondaga Trough was developed from this information. Water-quality samples were collected, and hydraulic head (water-level) measurements were made in the test wells. The water samples were analyzed for a variety of chemical constituents to determine the composition and age of saline waters within the aquifer. The geologic model, together with the water-quality and hydraulic-head data, supported

  1. Evaluating data worth for ground-water management under uncertainty

    Science.gov (United States)

    Wagner, B.J.

    1999-01-01

    A decision framework is presented for assessing the value of ground-water sampling within the context of ground-water management under uncertainty. The framework couples two optimization models-a chance-constrained ground-water management model and an integer-programing sampling network design model-to identify optimal pumping and sampling strategies. The methodology consists of four steps: (1) The optimal ground-water management strategy for the present level of model uncertainty is determined using the chance-constrained management model; (2) for a specified data collection budget, the monitoring network design model identifies, prior to data collection, the sampling strategy that will minimize model uncertainty; (3) the optimal ground-water management strategy is recalculated on the basis of the projected model uncertainty after sampling; and (4) the worth of the monitoring strategy is assessed by comparing the value of the sample information-i.e., the projected reduction in management costs-with the cost of data collection. Steps 2-4 are repeated for a series of data collection budgets, producing a suite of management/monitoring alternatives, from which the best alternative can be selected. A hypothetical example demonstrates the methodology's ability to identify the ground-water sampling strategy with greatest net economic benefit for ground-water management.A decision framework is presented for assessing the value of ground-water sampling within the context of ground-water management under uncertainty. The framework couples two optimization models - a chance-constrained ground-water management model and an integer-programming sampling network design model - to identify optimal pumping and sampling strategies. The methodology consists of four steps: (1) The optimal ground-water management strategy for the present level of model uncertainty is determined using the chance-constrained management model; (2) for a specified data collection budget, the monitoring

  2. Transport modeling

    Institute of Scientific and Technical Information of China (English)

    R.E. Waltz

    2007-01-01

    @@ There has been remarkable progress during the past decade in understanding and modeling turbulent transport in tokamaks. With some exceptions the progress is derived from the huge increases in computational power and the ability to simulate tokamak turbulence with ever more fundamental and physically realistic dynamical equations, e.g.

  3. Ground-water contribution to dose from past Hanford Operations

    Energy Technology Data Exchange (ETDEWEB)

    Freshley, M.D.; Thorne, P.D.

    1992-08-01

    The Hanford Environmental Dose Reconstruction (HEDR) Project is being conducted to estimate radiation doses that populations and individuals could have received from Hanford Site operations from 1944 to the present. Four possible pathways by which radionuclides migrating in ground water on the Hanford Site could have reached the public have been identified: (1) through contaminated ground water migrating to the Columbia River; (2) through wells on or adjacent to the Hanford Site; (3) through wells next to the Columbia River downstream of Hanford that draw some or all of their water from the river (riparian wells); and (4) through atmospheric deposition resulting in contamination of a small watershed that, in turn, results in contamination of a shallow well or spring by transport in the ground water. These four pathways make up the ground-water pathway,'' which is the subject of this study. Assessment of the ground-water pathway was performed by (1) reviewing the existing extensive literature on ground water and ground-water monitoring at Hanford and (2) performing calculations to estimate radionuclide concentrations where no monitoring data were collected. Radiation doses that would result from exposure to these radionuclides were calculated.

  4. Structure and application of an interface program between a geographic-information system and a ground-water flow model

    Science.gov (United States)

    Van Metre, P.C.

    1990-01-01

    A computer-program interface between a geographic-information system and a groundwater flow model links two unrelated software systems for use in developing the flow models. The interface program allows the modeler to compile and manage geographic components of a groundwater model within the geographic information system. A significant savings of time and effort is realized in developing, calibrating, and displaying the groundwater flow model. Four major guidelines were followed in developing the interface program: (1) no changes to the groundwater flow model code were to be made; (2) a data structure was to be designed within the geographic information system that follows the same basic data structure as the groundwater flow model; (3) the interface program was to be flexible enough to support all basic data options available within the model; and (4) the interface program was to be as efficient as possible in terms of computer time used and online-storage space needed. Because some programs in the interface are written in control-program language, the interface will run only on a computer with the PRIMOS operating system. (USGS)

  5. Fact Sheet: Environmental Pathway Models-Ground-Water Modeling in Support of Remedial Decision Making at Sites Contaminated with Radioactive Material

    Science.gov (United States)

    This fact sheet was designed to be used by technical staff responsible for identifying and implementing flow and transport models to support cleanup decisions at hazardous and radioactive waste sites.

  6. Contrast of evolution models for agricultural contaminants in ground waters by means of fuzzy logic and data mining

    Science.gov (United States)

    Andujar, J. M.; Aroba, J.; de Torre, M. L. La; Grande, J. A.

    2006-01-01

    This work aims at contrasting, by means of a set of fuzzy logic- and data mining-based algorithms, the functioning model of a detritic aquifer undergoing overexploitation and nitrate excess input coming from strawberry and citrus intensive crops in its recharge zone. To provide researchers unskilled in data mining techniques with an easy and intuitive interpretation, the authors have developed a computer tool based on fuzzy logic that allows immediate qualitative analysis of the data contained in a data mass from the water chemical analyses, and serves as a contrast to functioning models previously proposed with classical statistics.

  7. Case study on ground water flow (8)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    The report comprises research activities made in fiscal year 1997 under the contract of Japan Nuclear Fuel Cycle Development Center and the main items are: (1) Evaluation of water permeability through discontinuous hard bedrock in deep strata in relevant with underground disposal of radioactive wastes, (2) Three dimensional analysis of permeated water in bedrock, including flow analysis in T ono district using neuro-network and modification of Evaporation Logging System, (3) Development of hydraulic tests and necessary equipment applicable to measurements of complex dielectric constants of contaminated soils using FUDR-V method, this giving information on soil component materials, (4) Investigation methods and modeling of hydraulics in deep strata, (5) Geological study of ground water using environmental isotopes such as {sup 14}C, {sup 36}Cl and {sup 4}He, particularly measurement of ages of ground water using an accelerator-mass spectrometer, and (6) Re-submerging phenomena affecting the long-term geological stability. (S. Ohno)

  8. Case study on ground water flow (8)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    The report comprises research activities made in fiscal year 1997 under the contract of Japan Nuclear Fuel Cycle Development Center and the main items are: (1) Evaluation of water permeability through discontinuous hard bedrock in deep strata in relevant with underground disposal of radioactive wastes, (2) Three dimensional analysis of permeated water in bedrock, including flow analysis in T ono district using neuro-network and modification of Evaporation Logging System, (3) Development of hydraulic tests and necessary equipment applicable to measurements of complex dielectric constants of contaminated soils using FUDR-V method, this giving information on soil component materials, (4) Investigation methods and modeling of hydraulics in deep strata, (5) Geological study of ground water using environmental isotopes such as {sup 14}C, {sup 36}Cl and {sup 4}He, particularly measurement of ages of ground water using an accelerator-mass spectrometer, and (6) Re-submerging phenomena affecting the long-term geological stability. (S. Ohno)

  9. Compilation of geologic, hydrologic, and ground-water flow modeling information for the Spokane Valley-Rathdrum Prairie aquifer, Spokane County, Washington, and Bonner and Kootenai Counties, Idaho

    Science.gov (United States)

    Kahle, Sue C.; Caldwell, Rodney R.; Bartolino, James R.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources and Washington Department of Ecology compiled and described geologic, hydrologic, and ground-water flow modeling information about the Spokane Valley-Rathdrum Prairie (SVRP) aquifer in northern Idaho and northeastern Washington. Descriptions of the hydrogeologic framework, water-budget components, ground- and surface-water interactions, computer flow models, and further data needs are provided. The SVRP aquifer, which covers about 370 square miles including the Rathdrum Prairie, Idaho and the Spokane valley and Hillyard Trough, Washington, was designated a Sole Source Aquifer by the U.S. Environmental Protection Agency in 1978. Continued growth, water management issues, and potential effects on water availability and water quality in the aquifer and in the Spokane and Little Spokane Rivers have illustrated the need to better understand and manage the region's water resources. The SVRP aquifer is composed of sand, gravel, cobbles, and boulders primarily deposited by a series of catastrophic glacial outburst floods from ancient Glacial Lake Missoula. The material deposited in this high-energy environment is coarser-grained than is typical for most basin-fill deposits, resulting in an unusually productive aquifer with well yields as high as 40,000 gallons per minute. In most places, the aquifer is bounded laterally by bedrock composed of granite, metasedimentary rocks, or basalt. The lower boundary of the aquifer is largely unknown except along the margins or in shallower parts of the aquifer where wells have penetrated its entire thickness and reached bedrock or silt and clay deposits. Based on surface geophysics, the thickness of the aquifer is about 500 ft near the Washington-Idaho state line, but more than 600 feet within the Rathdrum Prairie and more than 700 feet in the Hillyard trough based on drilling records. Depth to water in the aquifer is greatest in the northern

  10. Subregions of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the subregions of the transient ground-water flow model of the Death Valley regional ground-water flow system (DVRFS). Subregions are...

  11. Investigation of Ground water Potential using Mathematical Model: A Case Study in Part of Northwest Region of Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Tarikul Islam

    2015-05-01

    Full Text Available Groundwater is the most essential and valuable resources for agriculture, domestic and industrial purposes. Unplanned withdrawal of groundwater is risky for the system due to limited replenishment and increasing water demand with continuously growing population, especially for the arid and semi-arid catchments. Scarcity of rainfall in time and reducing of upstream flow in the internal rivers have increased dependency on groundwater irrigation. Estimation of groundwater potential for a region is essential not only for sustainability of irrigation project but also for a sustainable water resources management at the regional level, which means in general at the basin scale. Due to the competition of all water users of a river basin, especially in water scarce regions, a comprehensive approach is needed regarding agricultural, domestic, industrial, and ecological aspects. In this paper, a case study was carried out for Pabna, Sirajgonj, Bogra, Gaibandha, Rangpur, Kurigram, Nilphamari and Lalamonirhat Districts which is situated in the north-west part of Bangladesh using physically distributed hydrological modelling. To bring about 3,000 km2 potential land under irrigation through sustainable water resources management, an integrated Groundwater-Surface Water model was developed using mathematical modelling tools which was calibrated for the period 2006-2010 and validated for the period 2011-2013. Using model result, groundwater water resources, requirement for present and future demand for various purposes and possible expansion of irrigation coverage for the study area were assessed. As a result irrigation coverage as well as agricultural production would be increased considerably if the project is implemented following the study findings and suggestions. So the study output has positive impact and for sustainable water resources management it is essential to use the state-of -the art technology.

  12. Modeling the impact of soil and water conservation on surface and ground water based on the SCS and Visual MODFLOW.

    Science.gov (United States)

    Wang, Hong; Gao, Jian-en; Zhang, Shao-long; Zhang, Meng-jie; Li, Xing-hua

    2013-01-01

    Soil and water conservation measures can impact hydrological cycle, but quantitative analysis of this impact is still difficult in a watershed scale. To assess the effect quantitatively, a three-dimensional finite-difference groundwater flow model (MODFLOW) with a surface runoff model-the Soil Conservation Service (SCS) were calibrated and applied based on the artificial rainfall experiments. Then, three soil and water conservation scenarios were simulated on the sand-box model to assess the effect of bare slope changing to grass land and straw mulching on water volume, hydraulic head, runoff process of groundwater and surface water. Under the 120 mm rainfall, 60 mm/h rainfall intensity, 5 m(2) area, 3° slope conditions, the comparative results indicated that the trend was decrease in surface runoff and increase in subsurface runoff coincided with the land-use converted from bare slope to grass land and straw mulching. The simulated mean surface runoff modulus was 3.64×10(-2) m(3)/m(2)/h in the bare slope scenario, while the observed values were 1.54×10(-2) m(3)/m(2)/h and 0.12×10(-2) m(3)/m(2)/h in the lawn and straw mulching scenarios respectively. Compared to the bare slope, the benefits of surface water reduction were 57.8% and 92.4% correspondingly. At the end of simulation period (T = 396 min), the simulated mean groundwater runoff modulus was 2.82×10(-2) m(3)/m(2)/h in the bare slope scenario, while the observed volumes were 3.46×10(-2) m(3)/m(2)/h and 4.91×10(-2) m(3)/m(2)/h in the lawn and straw mulching scenarios respectively. So the benefits of groundwater increase were 22.7% and 60.4% correspondingly. It was concluded that the soil and water conservation played an important role in weakening the surface runoff and strengthening the underground runoff. Meanwhile the quantitative analysis using a modeling approach could provide a thought for the study in a watershed scale to help decision-makers manage water resources.

  13. M3 version 3.0: Verification and validation; Hydrochemical model of ground water at repository site

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Javier B. (Dept. of Earth Sciences, Univ. of Zaragoza, Zaragoza (Spain)); Laaksoharju, Marcus (Geopoint AB, Sollentuna (Sweden)); Skaarman, Erik (Abscondo, Bromma (Sweden)); Gurban, Ioana (3D-Terra (Canada))

    2009-01-15

    Hydrochemical evaluation is a complex type of work that is carried out by specialists. The outcome of this work is generally presented as qualitative models and process descriptions of a site. To support and help to quantify the processes in an objective way, a multivariate mathematical tool entitled M3 (Multivariate Mixing and Mass balance calculations) has been constructed. The computer code can be used to trace the origin of the groundwater, and to calculate the mixing proportions and mass balances from groundwater data. The M3 code is a groundwater response model, which means that changes in the groundwater chemistry in terms of sources and sinks are traced in relation to an ideal mixing model. The complexity of the measured groundwater data determines the configuration of the ideal mixing model. Deviations from the ideal mixing model are interpreted as being due to reactions. Assumptions concerning important mineral phases altering the groundwater or uncertainties associated with thermodynamic constants do not affect the modelling because the calculations are solely based on the measured groundwater composition. M3 uses the opposite approach to that of many standard hydrochemical models. In M3, mixing is evaluated and calculated first. The constituents that cannot be described by mixing are described by reactions. The M3 model consists of three steps: the first is a standard principal component analysis, followed by mixing and finally mass balance calculations. The measured groundwater composition can be described in terms of mixing proportions (%), while the sinks and sources of an element associated with reactions are reported in mg/L. This report contains a set of verification and validation exercises with the intention of building confidence in the use of the M3 methodology. At the same time, clear answers are given to questions related to the accuracy and the precision of the results, including the inherent uncertainties and the errors that can be made

  14. M3 version 3.0: Verification and validation; Hydrochemical model of ground water at repository site

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Javier B. (Dept. of Earth Sciences, Univ. of Zaragoza, Zaragoza (Spain)); Laaksoharju, Marcus (Geopoint AB, Sollentuna (Sweden)); Skaarman, Erik (Abscondo, Bromma (Sweden)); Gurban, Ioana (3D-Terra (Canada))

    2009-01-15

    Hydrochemical evaluation is a complex type of work that is carried out by specialists. The outcome of this work is generally presented as qualitative models and process descriptions of a site. To support and help to quantify the processes in an objective way, a multivariate mathematical tool entitled M3 (Multivariate Mixing and Mass balance calculations) has been constructed. The computer code can be used to trace the origin of the groundwater, and to calculate the mixing proportions and mass balances from groundwater data. The M3 code is a groundwater response model, which means that changes in the groundwater chemistry in terms of sources and sinks are traced in relation to an ideal mixing model. The complexity of the measured groundwater data determines the configuration of the ideal mixing model. Deviations from the ideal mixing model are interpreted as being due to reactions. Assumptions concerning important mineral phases altering the groundwater or uncertainties associated with thermodynamic constants do not affect the modelling because the calculations are solely based on the measured groundwater composition. M3 uses the opposite approach to that of many standard hydrochemical models. In M3, mixing is evaluated and calculated first. The constituents that cannot be described by mixing are described by reactions. The M3 model consists of three steps: the first is a standard principal component analysis, followed by mixing and finally mass balance calculations. The measured groundwater composition can be described in terms of mixing proportions (%), while the sinks and sources of an element associated with reactions are reported in mg/L. This report contains a set of verification and validation exercises with the intention of building confidence in the use of the M3 methodology. At the same time, clear answers are given to questions related to the accuracy and the precision of the results, including the inherent uncertainties and the errors that can be made

  15. Simulation of solute transport of tetrachloroethylene in ground water of the glacial-drift aquifer at the Savage Municipal Well Superfund Site, Milford, New Hampshire, 1960-2000

    Science.gov (United States)

    Harte, Philip T.

    2004-01-01

    The Savage Municipal Well Superfund site, named after the former municipal water-supply well for the town of Milford, is underlain by a 0.5-square mile plume of volatile organic compounds (VOCs), primarily tetrachloroethylene (PCE). The plume occurs mostly within a highly transmissive sand-and-gravel unit, but also extends to an underlying till and bedrock unit. The plume logistically is divided into two areas termed Operable Unit No. 1 (OU1), which contains the primary source area, and Operable Unit No. 2 (OU2), which is the extended plume area. PCE concentrations in excess of 100,000 parts per billion (ppb) had been detected in the OU1 area in 1995, indicating a likely Dense Non-Aqueous Phase Liquid (DNAPL) source. In the fall of 1998, the New Hampshire Department of Environmental Services (NHDES) and the U.S. Environmental Protection Agency (USEPA) installed a remedial system in OU1. The OU1 remedial system includes a low-permeability barrier that encircles the highest detected concentrations of PCE, and a series of injection and extraction wells. The barrier primarily sits atop bedrock and penetrates the full thickness of the sand and gravel; and in some places, the full thickness of the underlying basal till. The sand and gravel unit and the till comprise the aquifer termed the Milford-Souhegan glacial-drift aquifer (MSGD). Two-dimensional and three-dimensional finite-difference solute-transport models of the unconsolidated sediments (MSGD aquifer) were constructed to help evaluate solute-transport processes, assess the effectiveness of remedial activities in OU1, and to help design remedial strategies in OU2. The solute-transport models simulate PCE concentrations, and model results were compared to observed concentrations of PCE. Simulations were grouped into the following three time periods: an historical calibration of the distribution of PCE from the initial input (circa 1960) of PCE into the subsurface to the 1990s, a pre-remedial calibration from 1995

  16. AQMAN; linear and quadratic programming matrix generator using two-dimensional ground-water flow simulation for aquifer management modeling

    Science.gov (United States)

    Lefkoff, L.J.; Gorelick, S.M.

    1987-01-01

    A FORTRAN-77 computer program code that helps solve a variety of aquifer management problems involving the control of groundwater hydraulics. It is intended for use with any standard mathematical programming package that uses Mathematical Programming System input format. The computer program creates the input files to be used by the optimization program. These files contain all the hydrologic information and management objectives needed to solve the management problem. Used in conjunction with a mathematical programming code, the computer program identifies the pumping or recharge strategy that achieves a user 's management objective while maintaining groundwater hydraulic conditions within desired limits. The objective may be linear or quadratic, and may involve the minimization of pumping and recharge rates or of variable pumping costs. The problem may contain constraints on groundwater heads, gradients, and velocities for a complex, transient hydrologic system. Linear superposition of solutions to the transient, two-dimensional groundwater flow equation is used by the computer program in conjunction with the response matrix optimization method. A unit stress is applied at each decision well and transient responses at all control locations are computed using a modified version of the U.S. Geological Survey two dimensional aquifer simulation model. The program also computes discounted cost coefficients for the objective function and accounts for transient aquifer conditions. (Author 's abstract)

  17. Radon determination in ground water

    Energy Technology Data Exchange (ETDEWEB)

    Segovia A, N.; Bulbulian G, S

    1991-08-15

    Studies on natural radioactivity in ground water were started in Mexico in San Luis Potosi state followed by samplings from deep wells and springs in the states of Mexico and Michoacan. The samples were analyzed for solubilized and {sup 226} Ra- supported {sup 222} Rn. Some of them were also studied for {sup 234} U/ {sup 238} U activity ratio. In this paper we discuss the activities obtained and their relationship with the geologic characteristics of the studied zones. (Author)

  18. Hanford Site ground-water monitoring for 1994

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.; Thorne, P.D.; Luttrell, S.P. [and others

    1995-08-01

    This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1994 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiologic and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1994 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1993 and June 1994. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal.

  19. Dynamic factor analysis for estimating ground water arsenic trends.

    Science.gov (United States)

    Kuo, Yi-Ming; Chang, Fi-John

    2010-01-01

    Drinking ground water containing high arsenic (As) concentrations has been associated with blackfoot disease and the occurrence of cancer along the southwestern coast of Taiwan. As a result, 28 ground water observation wells were installed to monitor the ground water quality in this area. Dynamic factor analysis (DFA) is used to identify common trends that represent unexplained variability in ground water As concentrations of decommissioned wells and to investigate whether explanatory variables (total organic carbon [TOC], As, alkalinity, ground water elevation, and rainfall) affect the temporal variation in ground water As concentration. The results of the DFA show that rainfall dilutes As concentration in areas under aquacultural and agricultural use. Different combinations of geochemical variables (As, alkalinity, and TOC) of nearby monitoring wells affected the As concentrations of the most decommissioned wells. Model performance was acceptable for 11 wells (coefficient of efficiency >0.50), which represents 52% (11/21) of the decommissioned wells. Based on DFA results, we infer that surface water recharge may be effective for diluting the As concentration, especially in the areas that are relatively far from the coastline. We demonstrate that DFA can effectively identify the important factors and common effects representing unexplained variability common to decommissioned wells on As variation in ground water and extrapolate information from existing monitoring wells to the nearby decommissioned wells.

  20. Heat, chloride, and specific conductance as ground water tracers near streams

    Science.gov (United States)

    Cox, M.H.; Su, G.W.; Constantz, J.

    2007-01-01

    Commonly measured water quality parameters were compared to heat as tracers of stream water exchange with ground water. Temperature, specific conductance, and chloride were sampled at various frequencies in the stream and adjacent wells over a 2-year period. Strong seasonal variations in stream water were observed for temperature and specific conductance. In observation wells where the temperature response correlated to stream water, chloride and specific conductance values were similar to stream water values as well, indicating significant stream water exchange with ground water. At sites where ground water temperature fluctuations were negligible, chloride and/or specific conductance values did not correlate to stream water values, indicating that ground water was not significantly influenced by exchange with stream water. Best-fit simulation modeling was performed at two sites to derive temperature-based estimates of hydraulic conductivities of the alluvial sediments between the stream and wells. These estimates were used in solute transport simulations for a comparison of measured and simulated values for chloride and specific conductance. Simulation results showed that hydraulic conductivities vary seasonally and annually. This variability was a result of seasonal changes in temperature-dependent hydraulic conductivity and scouring or clogging of the streambed. Specific conductance fits were good, while chloride data were difficult to fit due to the infrequent (quarterly) stream water chloride measurements during the study period. Combined analyses of temperature, chloride, and specific conductance led to improved quantification of the spatial and temporal variability of stream water exchange with shallow ground water in an alluvial system. ?? 2007 National Ground Water Association.

  1. Ground water recharge and flow characterization using multiple isotopes.

    Science.gov (United States)

    Chowdhury, Ali H; Uliana, Matthew; Wade, Shirley

    2008-01-01

    Stable isotopes of delta(18)O, delta(2)H, and (13)C, radiogenic isotopes of (14)C and (3)H, and ground water chemical compositions were used to distinguish ground water, recharge areas, and possible recharge processes in an arid zone, fault-bounded alluvial aquifer. Recharge mainly occurs through exposed stream channel beds as opposed to subsurface inflow along mountain fronts. This recharge distribution pattern may also occur in other fault-bounded aquifers, with important implications for conceptualization of ground water flow systems, development of ground water models, and ground water resource management. Ground water along the mountain front near the basin margins contains low delta(18)O, (14)C (percent modern carbon [pmC]), and (3)H (tritium units [TU]), suggesting older recharge. In addition, water levels lie at greater depths, and basin-bounding faults that locally act as a flow barrier may further reduce subsurface inflow into the aquifer along the mountain front. Chemical differences in ground water composition, attributed to varying aquifer mineralogy and recharge processes, further discriminate the basin-margin and the basin-center water. Direct recharge through the indurated sandstones and mudstones in the basin center is minimal. Modern recharge in the aquifer is mainly through the broad, exposed stream channel beds containing coarse sand and gravel where ground water contains higher delta(18)O, (14)C (pmC), and (3)H (TU). Spatial differences in delta(18)O, (14)C (pmC), and (3)H (TU) and occurrences of extensive mudstones in the basin center suggest sluggish ground water movement, including local compartmentalization of the flow system.

  2. Thicknesses of hydrogeologic units used in the hydrogeologic framework and transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital three-dimensional hydrogeologic framework model (HFM) represents the geometry and extent of hydrogeologic units (HGUs) and major structures in the Death...

  3. Surface altitudes of hydrogeologic units used in the hydrogeologic framework and transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital three-dimensional (3D) hydrogeologic framework model (HFM) represents the geometry and extent of hydrogeologic units (HGUs) and major structures in the...

  4. Surface altitudes of hydrogeologic units used in the hydrogeologic framework and transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital three-dimensional (3D) hydrogeologic framework model (HFM) represents the geometry and extent of hydrogeologic units (HGUs) and major structures in the...

  5. Thicknesses of hydrogeologic units used in the hydrogeologic framework and transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital three-dimensional hydrogeologic framework model (HFM) represents the geometry and extent of hydrogeologic units (HGUs) and major structures in the Death...

  6. SITE-94. Glaciation and regional ground-water flow in the Fennoscandian shield

    Energy Technology Data Exchange (ETDEWEB)

    Provost, A.M.; Voss, C.I.; Neuzil, C.E. [US Geological Survey, Reston, VA (United States)

    1998-02-01

    Results from a regional-scale ground-water flow model of the Fennoscandian shield suggest that ground-water flow is strongly affected by surface conditions associated with climatic change and glaciation. The model was used to run a series of numerical simulations of variable-density ground-water flow in a 1500-km-long and approximately 10-km-deep cross-section that passes through southern Sweden. Ground-water flow and shield brine transport in the cross-sectional model are controlled by an assumed time evolution of surface conditions over the next 140 ka. The simulation results suggest that vertical movement of deep shield brines induced by the next few glacial cycles should not increase the concentration of dissolved solids significantly above present-day levels. However, the concentration of dissolved solids should decrease significantly at depths of up to several kilometers during periods of glacial melt water recharge. The melt water may reside in the subsurface for periods exceeding 10 ka and may bring oxygenated conditions to an otherwise reducing chemical environment 33 refs, 32 figs, 4 tabs

  7. Bacteriophages as surface and ground water tracers

    Directory of Open Access Journals (Sweden)

    P. Rossi

    1998-01-01

    Full Text Available Bacteriophages are increasingly used as tracers for quantitative analysis in both hydrology and hydrogeology. The biological particles are neither toxic nor pathogenic for other living organisms as they penetrate only a specific bacterial host. They have many advantages over classical fluorescent tracers and offer the additional possibility of multi-point injection for tracer tests. Several years of research make them suitable for quantitative transport analysis and flow boundary delineation in both surface and ground waters, including karst, fractured and porous media aquifers. This article presents the effective application of bacteriophages based on their use in differing Swiss hydrological environments and compares their behaviour to conventional coloured dye or salt-type tracers. In surface water and karst aquifers, bacteriophages travel at about the same speed as the typically referenced fluorescent tracers (uranine, sulphurhodamine G extra. In aquifers of interstitial porosity, however, they appear to migrate more rapidly than fluorescent tracers, albeit with a significant reduction in their numbers within the porous media. This faster travel time implies that a modified rationale is needed for defining some ground water protection area boundaries. Further developments of other bacteriophages and their documentation as tracer methods should result in an accurate and efficient tracer tool that will be a proven alternative to conventional fluorescent dyes.

  8. Bacteriophages as surface and ground water tracers

    Science.gov (United States)

    Rossi, P.; Dörfliger, N.; Kennedy, K.; Müller, I.; Aragno, M.

    Bacteriophages are increasingly used as tracers for quantitative analysis in both hydrology and hydrogeology. The biological particles are neither toxic nor pathogenic for other living organisms as they penetrate only a specific bacterial host. They have many advantages over classical fluorescent tracers and offer the additional possibility of multi-point injection for tracer tests. Several years of research make them suitable for quantitative transport analysis and flow boundary delineation in both surface and ground waters, including karst, fractured and porous media aquifers. This article presents the effective application of bacteriophages based on their use in differing Swiss hydrological environments and compares their behaviour to conventional coloured dye or salt-type tracers. In surface water and karst aquifers, bacteriophages travel at about the same speed as the typically referenced fluorescent tracers (uranine, sulphurhodamine G extra). In aquifers of interstitial porosity, however, they appear to migrate more rapidly than fluorescent tracers, albeit with a significant reduction in their numbers within the porous media. This faster travel time implies that a modified rationale is needed for defining some ground water protection area boundaries. Further developments of other bacteriophages and their documentation as tracer methods should result in an accurate and efficient tracer tool that will be a proven alternative to conventional fluorescent dyes.

  9. Hanford ground-water data base management guide and user's manual. [CIRMIS

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, P.J.; Argo, R.S.; Bradymire, S.L.; Newbill, C.A.

    1985-05-01

    This management guide and user's manual is a working document for the computerized Hanford Ground-water Data Base maintained by the Geosciences Research and Engineering Department at Pacific Northwest Laboratory for the Hanford Ground-Water Surveillance Program. The program is managed by the Occupational and Environmental Protection Department for the US Department of Energy. The data base is maintained to provide rapid access to data that are rountinely collected from ground-water monitoring wells at the Hanford site. The data include water levels, sample analyses, geologic descriptions and well construction information of over 3000 existing or destroyed wells. These data are used to monitor water quality and for the evaluation of ground-water flow and pollutant transport problems. The management guide gives instructions for maintenance of the data base on the Digital Equipment Corporation PDP 11/70 Computer using the CIRMIS (Comprehensive Information Retrieval and Model Input Sequence) data base management software developed at Pacific Northwest Laboratory. Maintenance activities include inserting, modifying and deleting data, making back-up copies of the data base, and generating tables for annual monitoring reports. The user's guide includes instructions for running programs to retrieve the data in the form of listings of graphical plots. 3 refs.

  10. Simulation of the Regional Ground-Water-Flow System and Ground-Water/Surface-Water Interaction in the Rock River Basin, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.

    2009-01-01

    A regional, two-dimensional, areal ground-water-flow model was developed to simulate the ground-water-flow system and ground-water/surface-water interaction in the Rock River Basin. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Rock River Coalition. The objectives of the regional model were to improve understanding of the ground-water-flow system and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate ground-water/surface-water interactions, provide a framework for simulating regional ground-water-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate ground-water-flow patterns at multiple scales. The ground-water-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, ground-water/surface-water interactions, and ground-water withdrawals from high-capacity wells. The steady-state model treats the ground-water-flow system as a single layer with hydraulic conductivity and base elevation zones that reflect the distribution of lithologic groups above the Precambrian bedrock and a regionally significant confining unit, the Maquoketa Formation. In the eastern part of the Basin where the shale-rich Maquoketa Formation is present, deep ground-water flow in the sandstone aquifer below the Maquoketa Formation was not simulated directly, but flow into this aquifer was incorporated into the GFLOW model from previous work in southeastern Wisconsin. Recharge was constrained primarily by stream base-flow estimates and was applied uniformly within zones guided by regional infiltration estimates for soils. The model includes average ground-water withdrawals from 1997 to 2006 for municipal wells and from 1997 to 2005 for high-capacity irrigation, industrial, and commercial wells. In addition

  11. Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in U.S. ground water used for drinking (simulation depth 50 meters) -- Model output data set (gwava-dw_out)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents predicted nitrate concentration in ground water used for drinking, in milligrams per liter, in the conterminous United States, and was...

  12. 基于人工神经网络模型的地下水水位动态变化模拟%Dynamic Variation Simulation of Ground Water Table Based on Artificial Neural Network Model

    Institute of Scientific and Technical Information of China (English)

    魏光辉

    2015-01-01

    Predication of the ground water table plays an important role in planning management of catchement surface and ground water resources.In this study, the artificial neural network model is applied in predication of the ground water table around the Xinier reser-voir.By application of data from 6 monitoring wells in the study area and of the artificial neural network model, the ground water table af-ter one week is predicated by simulation.The factors input the model include evaporation, reservoir level, escape canal level, water pumped volume and ground water table of the monitoring wells in last week.Therefore, the model is with 15 input points and 6 output points.Three different neural network methods of GDX, LM and BR methods are applied for the predication of the ground water table. The study shows that all three methods perform well in the predication.Generally, BR performance is better than these of GDX and LM. The artificial neural network model trained by BR method is applied for the predication of the ground water table in future 2nd, 3rd and 4th weeks in the study area.The simulation results are still better although the accuracy of the predication of the ground water table slight-ly decreases with time increment.%地下水水位的预测在流域地表水和地下水资源的综合规划管理中起着非常重要的作用。在该研究中,人工神经网络模型被应用于希尼尔水库周边地下水水位的预测中。采用研究区6口地下水观测井资料,用人工神经网络模型进行模拟预测1周后的地下水水位。模型输入因子包括此前1周蒸发量、水库水位、排渠水位、抽水量和观测井地下水位,因此模型有15个输入节点和6个输出节点。将3种不同的神经网络训练算法,即自适应学习速率动量梯度下降反向传播算法( GDX)、LM算法和贝叶斯正则化算法( BR)用于地下水水位预测,并对模拟结果进行了评估。结果表明:3种神经

  13. Shallow Alluvial Aquifer Ground Water System and Surface Water/Ground Water Interaction, Boulder Creek, Boulder, Colorado

    Science.gov (United States)

    Babcock, K. P.; Ge, S.; Crifasi, R. R.

    2006-12-01

    Water chemistry in Boulder Creek, Colorado, shows significant variation as the Creek flows through the City of Boulder [Barber et al., 2006]. This variation is partially due to ground water inputs, which are not quantitatively understood. The purpose of this study is (1) to understand ground water movement in a shallow alluvial aquifer system and (2) to assess surface water/ground water interaction. The study area, encompassing an area of 1 mi2, is located at the Sawhill and Walden Ponds area in Boulder. This area was reclaimed by the City of Boulder and Boulder County after gravel mining operations ceased in the 1970's. Consequently, ground water has filled in the numerous gravel pits allowing riparian vegetation regrowth and replanting. An integrated approach is used to examine the shallow ground water and surface water of the study area through field measurements, water table mapping, graphical data analysis, and numerical modeling. Collected field data suggest that lateral heterogeneity exists throughout the unconsolidated sediment. Alluvial hydraulic conductivities range from 1 to 24 ft/day and flow rates range from 0.01 to 2 ft/day. Preliminary data analysis suggests that ground water movement parallels surface topography and does not noticeably vary with season. Recharge via infiltrating precipitation is dependent on evapotranspiration (ET) demands and is influenced by preferential flow paths. During the growing season when ET demand exceeds precipitation rates, there is little recharge; however recharge occurs during cooler months when ET demand is insignificant. Preliminary data suggest that the Boulder Creek is gaining ground water as it traverses the study area. Stream flow influences the water table for distances up to 400 feet. The influence of stream flow is reflected in the zones relatively low total dissolved solids concentration. A modeling study is being conducted to synthesize aquifer test data, ground water levels, and stream flow data. The

  14. GWVis: A tool for comparative ground-water data visualization

    Science.gov (United States)

    Best, Daniel M.; Lewis, Robert R.

    2010-11-01

    The Ground-Water Visualization application ( GWVis) presents ground-water data visually in order to educate the public on ground-water issues. It is also intended for presentations to government and other funding agencies. GWVis works with ground-water level elevation data collected or modeled over a given time span, together with a matching fixed underlying terrain. GWVis was developed using the Python programming language in conjunction with associated extension packages and application program interfaces such as OpenGLTM to improve performance and allow us fine control of attributes of the model such as lighting, material properties, transformations, and interpolation. There are currently several systems available for visualizing ground-water data. We classify these into two categories: research-oriented models and static presentation-based models. While both of them have their strengths, we find the former overly complex and non-intuitive and the latter not engaging and presenting problems showing multiple data dimensions. GWVis bridges the gap between static and research based visualizations by providing an intuitive, interactive design that allows participants to view the model from different perspectives, infer information about simulations, and view a comparison of two datasets. By incorporating scientific data in an environment that can be easily understood, GWVis allows that information to be presented to a large audience base.

  15. Characterizing Hydraulic Properties and Ground-Water Chemistry in Fractured-Rock Aquifers: A User's Manual for the Multifunction Bedrock-Aquifer Transportable Testing Tool (BAT3)

    Science.gov (United States)

    Shapiro, Allen M.

    2007-01-01

    A borehole testing apparatus has been designed to isolate discrete intervals of a bedrock borehole and conduct hydraulic tests or collect water samples for geochemical analyses. This borehole testing apparatus, referred to as the Multifunction Bedrock-Aquifer Transportable Testing Tool (BAT3), includes two borehole packers, which when inflated can form a pressure-tight seal against smooth borehole walls; a pump apparatus to withdraw water from between the two packers; a fluid-injection apparatus to inject water between the two packers; pressure transducers to monitor fluid pressure between the two packers, as well as above and below the packers; flowmeters to monitor rates of fluid withdrawal or fluid injection; and data-acquisition equipment to record and store digital records from the pressure transducers and flowmeters. The generic design of this apparatus was originally discussed in United States Patent Number 6,761,062 (Shapiro, 2004). The prototype of the apparatus discussed in this report is designed for boreholes that are approximately 6 inches in diameter and can be used to depths of approximately 300 feet below land surface. The apparatus is designed to fit in five hard plastic boxes that can be shipped by overnight freight car-riers. The equipment can be assembled rapidly once it is removed from the shipping boxes, and the length of the test interval (the distance between the two packers) can be adjusted to account for different borehole conditions without reconfiguring the downhole components. The downhole components of the Multifunction BAT3 can be lowered in a borehole using steel pipe or a cable; a truck mounted winch or a winch and tripod can be used for this purpose. The equipment used to raise and lower the downhole components of the Multifunction BAT3 must be supplied on site, along with electrical power, a compressor or cylinders of compressed gas to inflate the packers and operate downhole valves, and the proper length of tubing to connect the

  16. Finite-element three-dimensional ground-water (FE3DGW) flow model - formulation, program listings and users' manual

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S.K.; Cole, C.R.; Bond, F.W.

    1979-12-01

    The Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program is developing and applying the methodology for assessing the far-field, long-term post-closure safety of deep geologic nuclear waste repositories. AEGIS is being performed by Pacific Northwest Laboratory (PNL) under contract with the Office of Nuclear Waste Isolation (OWNI) for the Department of Energy (DOE). One task within AEGIS is the development of methodology for analysis of the consequences (water pathway) from loss of repository containment as defined by various release scenarios. Analysis of the long-term, far-field consequences of release scenarios requires the application of numerical codes which simulate the hydrologic systems, model the transport of released radionuclides through the hydrologic systems to the biosphere, and, where applicable, assess the radiological dose to humans. Hydrologic and transport models are available at several levels of complexity or sophistication. Model selection and use are determined by the quantity and quality of input data. Model development under AEGIS and related programs provides three levels of hydrologic models, two levels of transport models, and one level of dose models (with several separate models). This document consists of the description of the FE3DGW (Finite Element, Three-Dimensional Groundwater) Hydrologic model third level (high complexity) three-dimensional, finite element approach (Galerkin formulation) for saturated groundwater flow.

  17. Pesticides in Ground Water of the Maryland Coastal Plain

    Science.gov (United States)

    Denver, Judith M.; Ator, Scott W.

    2006-01-01

    Selected pesticides are detectable at low levels (generally less than 0.1 microgram per liter) in unconfined ground water in many parts of the Maryland Coastal Plain. Samples were recently collected (2001-04) from 47 wells in the Coastal Plain and analyzed for selected pesticides and degradate compounds (products of pesticide degradation). Most pesticide degradation occurs in the soil zone before infiltration to the water table, and degradates of selected pesticides were commonly detected in ground water, often at higher concentrations than their respective parent compounds. Pesticides and their degradates often occur in ground water in mixtures of multiple compounds, reflecting similar patterns in usage. All measured concentrations in ground water were below established standards for drinking water, and nearly all were below other health-based guidelines. Although drinking-water standards and guidelines are typically much higher than observed concentrations in ground water, they do not exist for many detected compounds (particularly degradates), or for mixtures of multiple compounds. The distribution of observed pesticide compounds reflects known usage patterns, as well as chemical properties and environmental factors that affect the fate and transport of these compounds in the environment. Many commonly used pesticides, such as glyphosate, pendimethalin, and 2,4-D were not detected in ground water, likely because they were sorbed onto organic matter or degraded in the soil zone. Others that are more soluble and (or) persistent, like atrazine, metolachlor, and several of their degradates, were commonly detected in ground water where they have been used. Atrazine, for example, an herbicide used primarily on corn, was most commonly detected in ground water on the Eastern Shore (where agriculture is common), particularly where soils are well drained. Conversely, dieldrin, an insecticide previously used heavily for termite control, was detected only on the Western

  18. Use of Ground-water Temperature Patterns to Determine the Hydraulic Conductance of the Streambed Along the Middle Reaches of the Russian River, CA

    Science.gov (United States)

    Su, G. W.; Constantz, J.; Jasperse, J.; Seymour, D.

    2002-12-01

    Along the Russian River in Sonoma County, the alluvial aquifer is the preferred source of drinking water because sediments and other constituents in the river water would require additional treatment. From late spring to early winter, an inflatable dam is erected to raise the river stage and passively recharge the alluvial aquifer. The raised stage also permits diversion of river water to a series of recharge ponds located near the dam along the river. Improved understanding of stream exchanges with ground water is needed to better manage available water resources. Heat is used as a tracer of shallow ground-water movement for detailed hydraulic parameter estimation along the middle reaches of the river. Water-levels and ground-water temperatures were measured in a series of observations wells and compared to the river stage and surface-water temperatures. Hydraulic conductivities were predicted by optimizing simulated ground-water temperatures using VS2DHI, a heat and water transport model, to observed temperatures in the aquifer. These conductivity values will be used in a stream/ground-water model of this region being developed using MODFLOW. Temperature-based estimates of streambed conductance will be inserted in the STREAM package of the model to constrain this parameter. Although temperature-based predictions of hydraulic conductivity vary significantly along the reach, the results generally suggest that an anisotropy of 5 to 1 (horizontal to vertical) provides the best hydraulic conductivity matches for predicted versus observed ground-water temperatures.

  19. Iowa ground-water quality

    Science.gov (United States)

    Buchmiller, R.C.; Squillace, P.J.; Drustrup, R.D.

    1987-01-01

    The population served by ground-water supplies in Iowa (fig. L4) is estimated to be about 2,392,000, or 82 percent of the total population (U.S. Geological Survey, 1985, p. 211). The population of Iowa is distributed fairly uniformly throughout the State (fig. IB), with 59 percent residing in rural areas or towns of less than 10,000 (U.S. Bureau of the Census, 1982). Surficial aquifers, the Jordan aquifer, and aquifers that form the uppermost bedrock aquifer in a particular area are most commonly used for drinking-water supplies and usually provide ample amounts of good quality water. However, naturally occurring properties or substances such as hardness, dissolved solids, and radioactivity limit the use of water for drinking purposes in some areas of each of the five principal aquifers (fig. 2/4). Median concentrations of nitrate in all aquifers and radium-226 in all aquifers except the Jordan are within the primary drinking-water standards established by the U.S. Environmental Protection Agency (1986a). Median concentrations for dissolved solids in the surficial, Dakota, and Jordan aquifers exceed secondary drinking-water standards established by the U.S. Environmental Protection Agency (1986b).

  20. Hanford Site ground-water monitoring for 1993

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.; Luttrell, S.P.; Evans, J.C. [and others

    1994-09-01

    This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1993 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiological and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1993 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1992 and June 1993. The greatest declines occurred in the 200-West Area. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal. Water levels remained nearly constant in the vicinity of B Pond, as a result of continued disposal to the pond. Water levels measured from wells in the unconfined aquifer north and east of the Columbia River indicate that the primary source of recharge is irrigation practices.

  1. Guide to Louisiana's ground-water resources

    Science.gov (United States)

    Stuart, C.G.; Knochenmus, D.D.; McGee, B.D.

    1994-01-01

    Ground water is one of the most valuable and abundant natural resources of Louisiana. Of the 4-.4 million people who live in the State, 61 percent use ground water as a source for drinking water. Most industrial and rural users and half of the irrigation users in the State rely on ground water. Quantity, however, is not the only aspect that makes ground water so valuable; quality also is important for its use. In most areas, little or no water treatment is required for drinking water and industrial purposes. Knowledge of Louisiana's ground-water resources is needed to ensure proper development and protection of this valuable resource. This report is designed to inform citizens about the availability and quality of ground water in Louisiana. It is not intended as a technical reference; rather, it is a guide to ground water and the significant role this resource plays in the state. Most of the ground water that is used in the State is withdrawn from 13 aquifers and aquifer systems: the Cockfield, Sparta, and Carrizo-Wilcox aquifersin northern Louisiana; Chicot aquifer system, Evangeline aquifer, Jasper aquifer system, and Catahoula aquifer in central and southwestern Louisiana; the Chicot equivalent, Evangeline equivalent, and Jasper equivalent aquifer systems in southeastern Louisiana; and the MississippiRiver alluvial, Red River alluvial, and upland terrace aquifers that are statewide. Ground water is affected by man's activities on the land surface, and the major ground-water concerns in Louisiana are: (1) contamination from surface disposal of hazardous waste, agricultural chemicals, and petroleum products; (2) contamination from surface wastes and saltwater through abandoned wells; (3) saltwater encroachment; and (4) local overdevelopment. Information about ground water in Louisiana is extensive and available to the public. Several State and Federal agencies provide published and unpublished material upon request.

  2. Hydrogeology, simulated ground-water flow, and ground-water quality, Wright-Patterson Air Force Base, Ohio

    Science.gov (United States)

    Dumouchelle, D.H.; Schalk, C.W.; Rowe, G.L.; De Roche, J.T.

    1993-01-01

    Ground water is the primary source of water in the Wright-Patterson Air Force Base area. The aquifer consists of glacial sands and gravels that fill a buried bedrock-valley system. Consolidated rocks in the area consist of poorly permeable Ordovician shale of the Richmondian stage, in the upland areas, the Brassfield Limestone of Silurian age. The valleys are filled with glacial sediments of Wisconsinan age consisting of clay-rich tills and coarse-grained outwash deposits. Estimates of hydraulic conductivity of the shales based on results of displacement/recovery tests range from 0.0016 to 12 feet per day; estimates for the glacial sediments range from less than 1 foot per day to more than 1,000 feet per day. Ground water flow from the uplands towards the valleys and the major rivers in the region, the Great Miami and the Mad Rivers. Hydraulic-head data indicate that ground water flows between the bedrock and unconsolidated deposits. Data from a gain/loss study of the Mad River System and hydrographs from nearby wells reveal that the reach of the river next to Wright-Patterson Air Force Base is a ground-water discharge area. A steady-state, three-dimensional ground-water-flow model was developed to simulate ground-water flow in the region. The model contains three layers and encompasses about 100 square miles centered on Wright-Patterson Air Force Base. Ground water enters the modeled area primarily by river leakage and underflow at the model boundary. Ground water exits the modeled area primarily by flow through the valleys at the model boundaries and through production wells. A model sensitivity analysis involving systematic changes in values of hydrologic parameters in the model indicates that the model is most sensitive to decreases in riverbed conductance and vertical conductance between the upper two layers. The analysis also indicates that the contribution of water to the buried-valley aquifer from the bedrock that forms the valley walls is about 2 to 4

  3. Geotechnics - the key to ground water protection

    DEFF Research Database (Denmark)

    Baumann, Jens; Foged, Niels; Jørgensen, Peter

    2000-01-01

    During the past 5 to 10 years research into ground water protection has proved that fractures in clay till may increase the hydraulic conductivity and herby the vulnerability of the ground water considerably. However, research has not identified a non-expensive and efficient method to map...

  4. Procedures for ground-water investigations

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water monitoring procedures are developed and used in accordance with the PNL Quality Assurance Program.

  5. Boundary of the area contributing flow to the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the area contributing ground-water flow to the Death Valley regional ground-water flow-system (DVRFS) model domain. The...

  6. Boundary of the area contributing flow to the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the area contributing ground-water flow to the Death Valley regional ground-water flow-system (DVRFS) model domain....

  7. Hydrogeology and simulation of ground-water flow at Arnold Air Force Base, Coffee and Franklin counties, Tennessee

    Science.gov (United States)

    Haugh, C.J.; Mahoney, E.N.

    1994-01-01

    The U.S. Air Force at Arnold Air Force Base (AAFB), in Coffee and Franklin Counties, Tennessee, is investigating ground-water contamination in selected areas of the base. This report documents the results of a comprehensive investigation of the regional hydrogeology of the AAFB area. Three aquifers within the Highland Rim aquifer system, the shallow aquifer, the Manchester aquifer, and the Fort Payne aquifer, have been identified in the study area. Of these, the Manchester aquifer is the primary source of water for domestic use. Drilling and water- quality data indicate that the Chattanooga Shale is an effective confining unit, isolating the Highland Rim aquifer system from the deeper, upper Central Basin aquifer system. A regional ground-water divide, approximately coinciding with the Duck River-Elk River drainage divide, underlies AAFB and runs from southwest to northeast. The general direction of most ground-water flow is to the north- west or to the northwest or to the southeast from the divide towards tributary streams that drain the area. Recharge estimates range from 4 to 11 inches per year. Digital computer modeling was used to simulate and provide a better understanding of the ground-water flow system. The model indicates that most of the ground-water flow occurs in the shallow and Manchester aquifers. The model was most sensitive to increases in hydraulic conductivity and changes in recharge rates. Particle-tracking analysis from selected sites of ground-water contamination indicates a potential for contami- nants to be transported beyond the boundary of AAFB.

  8. Hanford site ground water protection management plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    Ground water protection at the Hanford Site consists of preventative and remedial measures that are implemented in compliance with a variety of environmental regulations at local, state, and federal levels. These measures seek to ensure that the resource can sustain a broad range of beneficial uses. To effectively coordinate and ensure compliance with applicable regulations, the U.S. Department of Energy has issued DOE Order 5400.1 (DOE 1988a). This order requires all U.S. Department of Energy facilities to prepare separate ground water protection program descriptions and plans. This document describes the Ground Water Protection Management Plan (GPMP) for the Hanford Site located in the state of Washington. DOE Order 5400.1 specifies that the GPMP covers the following general topical areas: (1) documentation of the ground water regime; (2) design and implementation of a ground water monitoring program to support resource management and comply with applicable laws and regulations; (3) a management program for ground water protection and remediation; (4) a summary and identification of areas that may be contaminated with hazardous waste; (5) strategies for controlling hazardous waste sources; (6) a remedial action program; and (7) decontamination, decommissioning, and related remedial action requirements. Many of the above elements are currently covered by existing programs at the Hanford Site; thus, one of the primary purposes of this document is to provide a framework for coordination of existing ground water protection activities. The GPMP provides the ground water protection policy and strategies for ground water protection/management at the Hanford Site, as well as an implementation plan to improve coordination of site ground water activities.

  9. Simulations of Ground-Water Flow and Particle Pathline Analysis in the Zone of Contribution of a Public-Supply Well in Modesto, Eastern San Joaquin Valley, California

    Science.gov (United States)

    Burow, Karen R.; Jurgens, Bryant C.; Kauffman, Leon J.; Phillips, Steven P.; Dalgish, Barbara A.; Shelton, Jennifer L.

    2008-01-01

    Shallow ground water in the eastern San Joaquin Valley is affected by high nitrate and uranium concentrations and frequent detections of pesticides and volatile organic compounds (VOC), as a result of ground-water development and intensive agricultural and urban land use. A single public-supply well was selected for intensive study to evaluate the dominant processes affecting the vulnerability of public-supply wells in the Modesto area. A network of 23 monitoring wells was installed, and water and sediment samples were collected within the approximate zone of contribution of the public-supply well, to support a detailed analysis of physical and chemical conditions and processes affecting the water chemistry in the well. A three-dimensional, steady-state local ground-water-flow and transport model was developed to evaluate the age of ground water reaching the well and to evaluate the vulnerability of the well to nonpoint source input of nitrate and uranium. Particle tracking was used to compute pathlines and advective travel times in the ground-water flow model. The simulated ages of particles reaching the public-supply well ranged from 9 to 30,000 years, with a median of 54 years. The age of the ground water contributed to the public-supply well increased with depth below the water table. Measured nitrate concentrations, derived primarily from agricultural fertilizer, were highest (17 milligrams per liter) in shallow ground water and decreased with depth to background concentrations of less than 2 milligrams per liter in the deepest wells. Because the movement of water is predominantly downward as a result of ground-water development, and because geochemical conditions are generally oxic, high nitrate concentrations in shallow ground water are expected to continue moving downward without significant attenuation. Simulated long-term nitrate concentrations indicate that concentrations have peaked and will decrease in the public-supply well during the next 100 years

  10. Questa Baseline and Pre-Mining Ground-Water Quality Investigation. 25. Summary of Results and Baseline and Pre-Mining Ground-Water Geochemistry, Red River Valley, Taos County, New Mexico, 2001-2005

    Science.gov (United States)

    Nordstrom, D. Kirk

    2008-01-01

    Active and inactive mine sites are challenging to remediate because of their complexity and scale. Regulations meant to achieve environmental restoration at mine sites are equally challenging to apply for the same reasons. The goal of environmental restoration should be to restore contaminated mine sites, as closely as possible, to pre-mining conditions. Metalliferous mine sites in the Western United States are commonly located in hydrothermally altered and mineralized terrain in which pre-mining concentrations of metals were already anomalously high. Typically, those pre-mining concentrations were not measured, but sometimes they can be reconstructed using scientific inference. Molycorp?s Questa molybdenum mine in the Red River Valley, northern New Mexico, is located near the margin of the Questa caldera in a highly mineralized region. The State of New Mexico requires that ground-water quality standards be met on closure unless it can be shown that potential contaminant concentrations were higher than the standards before mining. No ground water at the mine site had been chemically analyzed before mining. The aim of this investigation, in cooperation with the New Mexico Environment Department (NMED), is to infer the pre-mining ground-water quality by an examination of the geologic, hydrologic, and geochemical controls on ground-water quality in a nearby, or proximal, analog site in the Straight Creek drainage basin. Twenty-seven reports contain details of investigations on the geological, hydrological, and geochemical characteristics of the Red River Valley that are summarized in this report. These studies include mapping of surface mineralogy by Airborne Visible-Infrared Imaging Spectrometry (AVIRIS); compilations of historical surface- and ground- water quality data; synoptic/tracer studies with mass loading and temporal water-quality trends of the Red River; reaction-transport modeling of the Red River; environmental geology of the Red River Valley; lake

  11. Simulation of ground-water flow in the vicinity of Hyde Park landfill, Niagara Falls, New York

    Science.gov (United States)

    Maslia, M.L.; Johnston, R.H.

    1982-01-01

    The Hyde Park landfill is a 15-acre chemical waste disposal site located north of Niagara Falls, New York. Underlying the site in descending order are: (1) low permeability glacial till, (2) a moderately permeable fractured rock aquifer--the Lockport Dolomite, and (3) a low permeability unit--the Rochester Shale. The site is bounded on three sides by ground-water drains; the Niagara River Gorge, the Niagara Power Project canal, and the power project conduits. A finite element model was used to simulate ground-water flow along an east-west section through the Hyde Park site (from the power project conduits to the Niagara Gorge). Steady-state conditions were simulated with an average annual recharge rate of 5 inches per year. The calibrated model simulated measured water levels within 5 feet in the glacial till and upper unit of the Lockport Dolomite and approximated the configuration of the water table. Based on simulation, ground-water flow near the Hyde Park site can be summarized as follows: 1. Specific discharge (Darcy velocity) ranges from about 0.01 to 0.1 foot per day in the upper unit of the Lockport Dolomite to less than 0.00001 foot per day in the Rochester Shale. Real velocities are highest in the upper unit of the Lockport, ranging from about 1.5 to 4.8 feet per day. 2. A ground-water divide exists east of the landfill, indicating that all ground water originating near or flowing beneath the landfill will flow toward and discharge in the gorge. 3. The zone of highest velocities (and presumably greatest potential for transporting chemical contaminants) includes the upper unit of the Lockport and part of the lower unit of the Lockport Dolomite between the landfill and the gorge. The time required for ground water to move from the landfill to the gorge in the Lockport Dolomite is estimated to be 5 to 7 years.

  12. Apparent chlorofluorocarbon age of ground water of the shallow aquifer system, Naval Weapons Station Yorktown, Yorktown, Virginia

    Science.gov (United States)

    Nelms, David L.; Harlow, George E.; Brockman, Allen R.

    2001-01-01

    reporting limit of 0.3 to 15.9 tritium units (TU) with a median value of 10.8 TU. Water-quality field properties are highly variable for ground water with apparent CFC ages less than 15 years because of geochemical processes within local flow systems. Ground water with apparent CFC ages greater than 15 years represents more stable conditions in subregional flow systems.The range of apparent CFC ages is slightly greater than the ranges in time of travel of ground water calculated for shallow wells (less than 60- feet deep) from flow-path analysis. Calculated travel times to springs can be up to two orders of magnitude greater than the CFC-based apparent ages. Reasonable assumptions of values for hydraulic parameters can result in substantial overestimates for time of travel to springs.Recharge rates computed from apparent CFC ages range from 0.29 to 0.89 feet per year (ft/ yr) with an average value of 0.54 ft/yr. The analysis of apparent CFC ages in conjunction with geohydrologic data indicates that young water (less than 50 years) is present at depth (nearly 120 feet) and that both local and subregional flow systems occur in the shallow aquifer system at the Station. The addition of the dimension of time to the three-dimensional framework of Brockman and others (1997) will benefit current (2001) and future remediation activities by providing estimates of advective transport rates and how these rates vary depending upon geohydrologic setting and position within the ground-water-flow system. Estimated ground-water apparent ages and recharge rates can be used as calibration criteria in simulations of ground-water flow on the Station to refine and constrain future ground-water-flow models of the shallow aquifer system.

  13. Ground-Water Protection and Monitoring Program

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the ground-water protection and monitoring program strategy for the Hanford Site in 1994. Two of the key elements of this strategy are to (1) protect the unconfined aquifer from further contamination, and (2) conduct a monitoring program to provide early warning when contamination of ground water does occur. The monitoring program at Hanford is designed to document the distribution and movement of existing ground-water contamination and provides a historical baseline for evaluating current and future risk from exposure to the contamination and for deciding on remedial action options.

  14. Characterizing Ground-Water Flow Paths in High-Altitude Fractured Rock Settings Impacted by Mining Activities

    Science.gov (United States)

    Wireman, M.; Williams, D.

    2003-12-01

    investigations have been used to develop a sound conceptual model of ground-water flow and transport of heavy metals from the mine workings to Chalk Creek. Ground-water tracing techniques (using organic, fluorescent dyes) have been successfully used to delineate ground-water flow paths. Surface-water tracing techniques have been used to acquire very accurate stream flow measuements and to identify ground-water inflow zones to streams. Stable (O18/D)and radioactive (tritium,sulphur 35) isotope anlysis of waters flowing into and out of underground workings have proved useful for conducting end member mixing analysis to determine which inflows and outflows are most significant with respect to metals loading. Hydrogeologic mapping, inverse geochemical modeling (using MINTEQAK code)and helium 3 analysis of ground water have also proven to useful tools. These tools, used in combination have provided multiple lines of evidence regarding the nature, timing and magnitude of ground-water inflow into underground mine workings and the distribution and types of hydrologic pathways that transport metals from the underground workings to Chalk Creek. This paper presents the results of some of the more important hydrologic investigations completed at the site and a conceptual model of ground-water flow in fractured rock settings that have been impacted by underground mining activites.

  15. 40 CFR 265.91 - Ground-water monitoring system.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Ground-water monitoring system. 265.91... DISPOSAL FACILITIES Ground-Water Monitoring § 265.91 Ground-water monitoring system. (a) A ground-water monitoring system must be capable of yielding ground-water samples for analysis and must consist of: (1...

  16. GROUND WATER CONTAMINATION POTENTIAL FROM STORMWATER INFILTRATION

    Science.gov (United States)

    Prior to urbanization, ground water recharge resulted from infiltration of precipitation through pervious surfaces, including grasslands and woods. This infiltration water was relatively uncontaminated. With urbanization, the permeable soil surface area through which recharge by...

  17. Section 10: Ground Water - Waste Characteristics & Targets

    Science.gov (United States)

    HRS Training. The waste characteristics factor category in the ground water pathway is made up of two components: the toxicity/mobility of the most hazardous substance associated with the site and the hazardous waste quantity at the site.

  18. Section 9: Ground Water - Likelihood of Release

    Science.gov (United States)

    HRS training. the ground water pathway likelihood of release factor category reflects the likelihood that there has been, or will be, a release of hazardous substances in any of the aquifers underlying the site.

  19. Estimating ground water discharge by hydrograph separation.

    Science.gov (United States)

    Hannula, Steven R; Esposito, Kenneth J; Chermak, John A; Runnells, Donald D; Keith, David C; Hall, Larry E

    2003-01-01

    Iron Mountain is located in the West Shasta Mining District in California. An investigation of the generation of acid rock drainage and metals loading to Boulder Creek at Iron Mountain was conducted. As part of that investigation, a hydrograph separation technique was used to determine the contribution of ground water to total flow in Boulder Creek. During high-flow storm events in the winter months, peak flow in Boulder Creek can exceed 22.7 m3/sec, and comprises surface runoff, interflow, and ground water discharge. A hydrograph separation technique was used to estimate ground water discharge into Boulder Creek during high-flow conditions. Total ground water discharge to the creek approaches 0.31 m3/sec during the high-flow season. The hydrograph separation technique combined with an extensive field data set provided reasonable estimates of ground water discharge. These estimates are useful for other investigations, such as determining a corresponding metals load from the metal-rich ground water found at Iron Mountain and thus contributing to remedial alternatives.

  20. Ground water flow analysis of a mid-Atlantic outer coastal plain watershed, Virginia, U.S.A.

    Science.gov (United States)

    Robinson, Michael A; Reay, William G

    2002-01-01

    Models for ground water flow (MODFLOW) and particle tracking (MODPATH) were used to determine ground water flow patterns, principal ground water discharge and recharge zones, and estimates of ground water travel times in an unconfined ground water system of an outer coastal plain watershed on the Delmarva Peninsula, Virginia. By coupling recharge and discharge zones within the watershed, flowpath analysis can provide a method to locate and implement specific management strategies within a watershed to reduce ground water nitrogen loading to surface water. A monitoring well network was installed in Eyreville Creek watershed, a first-order creek, to determine hydraulic conductivities and spatial and temporal variations in hydraulic heads for use in model calibration. Ground water flow patterns indicated the convergence of flow along the four surface water features of the watershed; primary discharge areas were in the nontidal portions of the watershed. Ground water recharge zones corresponded to the surface water features with minimal development of a regional ground water system. Predicted ground water velocities varied between water features. Some ground water residence times exceeded 100 years, although average residence times ranged between 16 and 21 years; approximately 95% of the ground water resource would reflect land use activities within the last 50 years.

  1. Ground water budget analysis and cross-formational leakage in an arid basin.

    Science.gov (United States)

    Hutchison, William R; Hibbs, Barry J

    2008-01-01

    Ground water budget analysis in arid basins is substantially aided by integrated use of numerical models and environmental isotopes. Spatial variability of recharge, storage of water of both modern and pluvial age, and complex three-dimensional flow processes in these basins provide challenges to the development of a good conceptual model. Ground water age dating and mixing analysis with isotopic tracers complement standard hydrogeologic data that are collected and processed as an initial step in the development and calibration of a numerical model. Environmental isotopes can confirm or refute a priori assumptions of ground water flow, such as the general assumption that natural recharge occurs primarily along mountains and mountain fronts. Isotopes also serve as powerful tools during postaudits of numerical models. Ground water models provide a means of developing ground water budgets for entire model domains or for smaller regions within the model domain. These ground water budgets can be used to evaluate the impacts of pumping and estimate the magnitude of capture in the form of induced recharge from streams, as well as quantify storage changes within the system. The coupled analyses of ground water budget analysis and isotope sampling and analysis provide a means to confirm, refute, or modify conceptual models of ground water flow.

  2. Modelling removal mechanisms of Pb, Cu, Zn and Cd in acidic groundwater during the neutralization by ambient surface and ground waters

    Science.gov (United States)

    Paulson, Anthony J.; Balistrieri, Laurie S.

    1999-01-01

    Removal of Pb, Cu, Zn, and Cd during neutralization of acid rock drainage is examined using model simulations of field conditions and laboratory experiments involving mixing of natural drainage and surface waters or groundwaters. The simulations consider sorption onto hydrous Fe and Al oxides and particulate organic carbon, mineral precipitation, and organic and inorganic solution complexation of metals for two physical systems where newly formed oxides and particulate organic matter are either transported or retained along the chemical pathway. The calculations indicate that metal removal is a strong function of the physical system. Relative to direct discharge of ARD into streams, lower metal removals are observed where ARD enters streamwaters during the latter stages of neutralization by ambient groundwater after most of the Fe has precipitated and been retained in the soils. The mixing experiments, which represent the field simulations, also demonstrated the importance of dissolved metal to particle Fe ratios in controlling dissolved metal removal along the chemical pathway. Finally, model calculations indicate that hydrous Fe oxides and particulate organic carbon are more important than hydrous Al oxides in removing metals and that both inorganic and organic complexation must be considered when modeling metal removal from aquatic systems that are impacted by sulfide oxidation.

  3. Climatic-geologic conditions in ground water radon concentrations; Condicionamento climatico-geologico na concentracao de radonio em aguas subterraneas

    Energy Technology Data Exchange (ETDEWEB)

    Rebelo, Antonio M.A.; Jachic, Joao; Souza, Nereu J.M. de [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil); Bittencourt, Andre V.L. [Parana Univ., Curitiba, PR (Brazil). Dept. de Geologia

    1997-12-01

    In regions with warm and moist climates uranium and thorium leaching and redistribution in landscapes, under evolution of the weathering processes upon existent radioanomalous rocks, may be regarded as the principal conditions to the understanding of the geologic controls on radon ({sup 222} Rn and {sup 22O} Rn) emanation, concentration diffusion and transport from rocks and soils to ground waters and atmosphere. On the basis of the concepts of landscape geochemistry and geochemical behaviour of U and Th, a study of a virtual radioanomalous granitic context is performed. A mathematical model simulates the concentration variations of Ra and Rn in ground waters as result of U leaching and redistribution in materials and of Rn recoil transport after Ra radioactive decay around the pores. (author). 13 refs., 1 fig.

  4. Artificial recharge of humic ground water.

    Science.gov (United States)

    Alborzfar, M; Villumsen, A; Grøn, C

    2001-01-01

    The purpose of this study was to investigate the efficiency of soil in removing natural organic matter from humic ground waters using artificial recharge. The study site, in western Denmark, was a 10,000 ml football field of which 2,000 m2 served as an infiltration field. The impact of the artificial recharge was studied by monitoring the water level and the quality of the underlying shallow aquifer. The humic ground water contained mainly humic adds with an organic carbon (OC) concentration of 100 to 200 mg C L(-1). A total of 5,000 mS of humic ground water were sprinkled onto the infiltration field at an average rate of 4.25 mm h(-1). This resulted in a rise in the water table of the shallow aquifer. The organic matter concentration of the water in the shallow aquifer, however, remained below 2.7 mg C L(-1). The organic matter concentration of the pore water in the unsaturated zone was measured at the end of the experiment. The organic matter concentration of the pore water decreased from 105 mg C L(-1) at 0.5 m to 20 mg C L(-1) at 2.5 m under the infiltration field indicating that the soil removed the organic matter from the humic ground water. From these results we conclude that artificial recharge is a possible method for humic ground water treatment.

  5. Ground Water Quality of Selected Wells

    Directory of Open Access Journals (Sweden)

    Mosher R. Ahmed

    2013-05-01

    Full Text Available In order to characterize ground water quality in Zaweta district / Dohuk governorate, eight wells are selected to represent their water quality. Monthly samples are collected from the wells for the period from October 2005 to April 2006. The samples are tested for conductivity, total dissolved solids, pH, total hardness, chloride, alkalinity and nitrate according to the standard methods. The results of statistical analysis showed significant difference among the wells water quality in the measured parameters. Ground water quality of Zaweta district has high dissolved ions due to the nature of studied area rocks. Total dissolved solids of more than 1000 mg/l made the wells Gre-Qassroka, Kora and Swaratoka need to be treated to make taste palatable. Additionally high electrical conductivity and TDS made Zaweta ground water have a slight to moderate restriction to crop growth. The high alkalinity of Zaweta ground water indicated stabilized pH. The water quality of all the wells is found excessively hard. The nitrate concentration of Zaweta ground water ranged between 0.19-42.4 mg/l below the guidelines for WHO and the maximum nitrate concentration is recorded in Kora well .

  6. Geohydrology, Geochemistry, and Ground-Water Simulation-Optimization of the Central and West Coast Basins, Los Angeles County, California

    Science.gov (United States)

    Reichard, Eric G.; Land, Michael; Crawford, Steven M.; Johnson, Tyler D.; Everett, Rhett; Kulshan, Trayle V.; Ponti, Daniel J.; Halford, Keith L.; Johnson, Theodore A.; Paybins, Katherine S.; Nishikawa, Tracy

    2003-01-01

    abundant tritium (greater than 8 tritium units) is found in and downgradient from the Montebello Forebay and near the seawater barrier projects, indicating recent recharge. Water with less than measurable tritium is present in, and downgradient from, the Los Angeles Forebay and in most wells in the West Coast Basin. Water from several deep wells was analyzed for carbon-14. Uncorrected estimates of age for these samples range from 600 to more than 20,000 years before present. Chemical and isotopic data are combined to evaluate changes in chemical character along flow paths emanating from the Montebello and Los Angeles Forebays. A four-layer ground-water flow model was developed to simulate steady-state ground-water conditions representative of those in 1971 and transient conditions for the period 1971?2000. Model results indicate increases in ground-water storage in all parts of the study area over the simulated thirty-year period. The model was used to develop a three-dimensional ground-water budget and to assess impacts of two alternative future (2001?25) ground-water development scenarios?one that assumes continued pumping at average current rates and a second that assumes increasing pumping from most wells in the Central Basin. The model simulates stable or slightly increasing water levels for the first scenario and declining water levels (25 to 50 ft in the Central Basin) in the second scenario. Model sensitivity to parameter values and to the assumed Orange County boundary condition was evaluated. Particle tracking was applied to simulate advective transport of water from the spreading ponds, the coastline, and the seawater injection barriers. Particle tracking results indicate that most flow within the Upper San Pedro aquifer system occurs within about 20 percent of the total aquifer system thickness and that virtually all water injected into the seawater barrier projects has flowed inland. The simulation model was linked with optimizatio

  7. UZ Colloid Transport Model

    Energy Technology Data Exchange (ETDEWEB)

    M. McGraw

    2000-04-13

    The UZ Colloid Transport model development plan states that the objective of this Analysis/Model Report (AMR) is to document the development of a model for simulating unsaturated colloid transport. This objective includes the following: (1) use of a process level model to evaluate the potential mechanisms for colloid transport at Yucca Mountain; (2) Provide ranges of parameters for significant colloid transport processes to Performance Assessment (PA) for the unsaturated zone (UZ); (3) Provide a basis for development of an abstracted model for use in PA calculations.

  8. Numerical simulation of vertical ground-water flux of the Rio Grande from ground-water temperature profiles, central New Mexico

    Science.gov (United States)

    Bartolino, James R.; Niswonger, Richard G.

    1999-01-01

    An important gap in the understanding of the hydrology of the Middle Rio Grande Basin, central New Mexico, is the rate at which water from the Rio Grande recharges the Santa Fe Group aquifer system. Several methodologies-including use of the Glover-Balmer equation, flood pulses, and channel permeameters- have been applied to this problem in the Middle Rio Grande Basin. In the work presented here, ground-water temperature profiles and ground-water levels beneath the Rio Grande were measured and numerically simulated at four sites. The direction and rate of vertical ground-water flux between the river and underlying aquifer was simulated and the effective vertical hydraulic conductivity of the sediments underlying the river was estimated through model calibration. Seven sets of nested piezometers were installed during July and August 1996 at four sites along the Rio Grande in the Albuquerque area, though only four of the piezometer nests were simulated. In downstream order, these four sites are (1) the Bernalillo site, upstream from the New Mexico State Highway 44 bridge in Bernalillo (piezometer nest BRN02); (2) the Corrales site, upstream from the Rio Rancho sewage treatment plant in Rio Rancho (COR01); (3) the Paseo del Norte site, upstream from the Paseo del Norte bridge in Albuquerque (PDN01); and (4) the Rio Bravo site, upstream from the Rio Bravo bridge in Albuquerque (RBR01). All piezometers were completed in the inner-valley alluvium of the Santa Fe Group aquifer system. Ground-water levels and temperatures were measured in the four piezometer nests a total of seven times in the 24-month period from September 1996 through August 1998. The flux between the surface- and ground-water systems at each of the field sites was quantified by one-dimensional numerical simulation of the water and heat exchange in the subsurface using the heat and water transport model VS2DH. Model calibration was aided by the use of PEST, a model-independent computer program that uses

  9. Reagent removal of manganese from ground water

    Science.gov (United States)

    Brayalovsky, G.; Migalaty, E.; Naschetnikova, O.

    2017-06-01

    The study is aimed at the technology development of treating drinking water from ground waters with high manganese content and oxidizability. Current technologies, physical/chemical mechanisms and factors affecting in ground treatment efficiency are reviewed. Research has been conducted on manganese compound removal from ground waters with high manganese content (5 ppm) and oxidizability. The studies were carried out on granular sorbent industrial ODM-2F filters (0.7-1.5 mm fraction). It was determined that conventional reagent oxidization technologies followed by filtration do not allow us to obtain the manganese content below 0.1 ppm when treating ground waters with high oxidizability. The innovative oxidation-based manganese removal technology with continuous introduction of reaction catalytic agent is suggested. This technology is effective in alkalization up to pH 8.8-9. Potassium permanganate was used as a catalytic agent, sodium hypochlorite was an oxidizer and cauistic soda served an alkalifying agent.

  10. Ground-water quality atlas of Wisconsin

    Science.gov (United States)

    Kammerer, Phil A.

    1981-01-01

    This report summarizes data on ground-water quality stored in the U.S. Geological Survey's computer system (WATSTORE). The summary includes water quality data for 2,443 single-aquifer wells, which tap one of the State's three major aquifers (sand and gravel, Silurian dolomite, and sandstone). Data for dissolved solids, hardness, alkalinity, calcium, magnesium, sodium, potassium, iron, manganese, sulfate, chloride, fluoride, and nitrate are summarized by aquifer and by county, and locations of wells for which data are available 1 are shown for each aquifer. Calcium, magnesium, and bicarbonate (the principal component of alkalinity) are the major dissolved constituents in Wisconsin's ground water. High iron concentrations and hardness cause ground-water quality problems in much of the State. Statewide ,summaries of trace constituent (selected trace metals; arsenic, boron, and organic carbon) concentrations show that these constituents impair water quality in only a few isolated wells.

  11. MODFLOW-2000, the U.S. Geological Survey modular ground-water model -- Documentation of the Model-Layer Variable-Direction Horizontal Anisotropy (LVDA) capability of the Hydrogeologic-Unit Flow (HUF) package

    Science.gov (United States)

    Anderman, Evan R.; Kipp, K.L.; Hill, Mary C.; Valstar, Johan; Neupauer, R.M.

    2002-01-01

    This report documents the model-layer variable-direction horizontal anisotropy (LVDA) capability of the Hydrogeologic-Unit Flow (HUF) Package of MODFLOW-2000. The LVDA capability allows the principal directions of horizontal anisotropy to be different than the model-grid row and column directions, and for the directions to vary on a cell-by-cell basis within model layers. The HUF Package calculates effective hydraulic properties for model grid cells based on hydraulic properties of hydrogeologic units with thicknesses defined independently of the model layers. These hydraulic properties include, among other characteristics, hydraulic conductivity and a horizontal anisotropy ratio. Using the LVDA capability, horizontal anisotropy direction is defined for model grid cells within which one or more hydrogeologic units may occur. For each grid cell, the HUF Package calculates the effective horizontal hydraulic conductivity along the primary direction of anisotropy using the hydrogeologic-unit hydraulic conductivities, and calculates the effective horizontal hydraulic conductivity along the orthogonal anisotropy direction using the effective primary direction hydraulic conductivities and horizontal anisotropy ratios. The direction assigned to the model layer effective primary hydraulic conductivity is specified using a new data set defined by the LVDA capability, when active, to calculate coefficients needed to solve the ground-water flow equation. Use of the LVDA capability is illustrated in four simulation examples, which also serve to verify hydraulic heads, advective-travel paths, and sensitivities calculated using the LVDA capability. This version of the LVDA capability defines variable-direction horizontal anisotropy using model layers, not the hydrogeologic units defined by the HUF Package. This difference needs to be taken into account when designing model layers and hydrogeologic units to produce simulations that accurately represent a given field problem. This

  12. Contamination of ground water, surface water, and soil, and evaluation of selected ground-water pumping alternatives in the Canal Creek area of Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Lorah, Michelle M.; Clark, Jeffrey S.

    1996-01-01

    Chemical manufacturing, munitions filling, and other military-support activities have resulted in the contamination of ground water, surface water, and soil in the Canal Creek area of Aberdeen Proving Ground, Maryland. Chlorinated volatile organic compounds, including 1,1,2,2-tetrachloroethane and trichloroethylene, are widespread ground-water contaminants in two aquifers that are composed of unconsolidated sand and gravel. Distribution and fate of chlorinated organic compounds in the ground water has been affected by the movement and dissolution of solvents in their dense immiscible phase and by microbial degradation under anaerobic conditions. Detection of volatile organic contaminants in adjacent surface water indicates that shallow contaminated ground water discharges to surface water. Semivolatile organic compounds, especially polycyclic aromatic hydrocarbons, are the most prevalent organic contaminants in soils. Various trace elements, such as arsenic, cadmium, lead, and zinc, were found in elevated concentrations in ground water, surface water, and soil. Simulations with a ground-water-flow model and particle tracker postprocessor show that, without remedial pumpage, the contaminants will eventually migrate to Canal Creek and Gunpowder River. Simulations indicate that remedial pumpage of 2.0 million gallons per day from existing wells is needed to capture all particles originating in the contaminant plumes. Simulated pumpage from offsite wells screened in a lower confined aquifer does not affect the flow of contaminated ground water in the Canal Creek area.

  13. Seepage laws in aquifer near a partially penetrating river with an intensive extraction of ground water

    Institute of Scientific and Technical Information of China (English)

    刘国东; 李俊亭

    1997-01-01

    The intensive extraction of ground water from aquifers near a river is an efficient way to exploit ground water resources. A lot of problems, however, have arisen because the mechanism of ground water flow in this way has not been clear. A sand-box model and a numerical model are respectively used to simulate the extraction of ground water near a partially penetrating river physically and theoretically. The results show that the ground water will lose saturated hydraulic connection with the river water as the pumping intensity increases. The broken point of hydraulic connection is located in the interior of aquifers rather than on the riverbed. After hydraulic disconnection occurs, two saturated zones, a suspended saturated zone linked with river and an unconfined aquifer, are formed.

  14. Geochemistry and the understanding of ground-water systems

    Science.gov (United States)

    Glynn, Pierre D.; Plummer, L. Niel

    2005-03-01

    Geochemistry has contributed significantly to the understanding of ground-water systems over the last 50 years. Historic advances include development of the hydrochemical facies concept, application of equilibrium theory, investigation of redox processes, and radiocarbon dating. Other hydrochemical concepts, tools, and techniques have helped elucidate mechanisms of flow and transport in ground-water systems, and have helped unlock an archive of paleoenvironmental information. Hydrochemical and isotopic information can be used to interpret the origin and mode of ground-water recharge, refine estimates of time scales of recharge and ground-water flow, decipher reactive processes, provide paleohydrological information, and calibrate ground-water flow models. Progress needs to be made in obtaining representative samples. Improvements are needed in the interpretation of the information obtained, and in the construction and interpretation of numerical models utilizing hydrochemical data. The best approach will ensure an optimized iterative process between field data collection and analysis, interpretation, and the application of forward, inverse, and statistical modeling tools. Advances are anticipated from microbiological investigations, the characterization of natural organics, isotopic fingerprinting, applications of dissolved gas measurements, and the fields of reaction kinetics and coupled processes. A thermodynamic perspective is offered that could facilitate the comparison and understanding of the multiple physical, chemical, and biological processes affecting ground-water systems. La géochimie a contribué de façon importante à la compréhension des systèmes d'eaux souterraines pendant les 50 dernières années. Les avancées ont portées sur le développement du concept des faciès hydrochimiques, sur l'application de la théorie des équilibres, l'étude des processus d'oxydoréduction, et sur la datation au radiocarbone. D'autres concepts, outils et

  15. Induced infiltration from the Rockaway River and water chemistry in a stratified-drift aquifer at Dover, New Jersey, with a section on modeling ground-water flow in the Rockaway River Valley

    Science.gov (United States)

    Dysart, Joel E.; Rheaume, Stephen J.; Kontis, Angelo L.

    1999-01-01

    The vertical hydraulic conductivity per unit thickness (streambed leakance) of unconsolidated sediment immediately beneath the channel of the Rockaway River near a municipal well field at Dover, N.J., is between 0.2 and 0.6 feet per day per foot and is probably near the low end of this range. This estimate is based on evaluation of three lines of evidence: (1) Streamflow measurements, which indicated that induced infiltration of river water near the well field averaged 0.67 cubic feet per second; (2) measurements of the rate of downward propagation of diurnal fluctuations in dissolved oxygen and water temperature at three piezometers, which indicated vertical Darcian flow velocities of 0.6 and 1.5 feet per day, respectively; and (3) chemical mixing models based on stable isotopes of oxygen and hydrogen, which indicated that 30 percent of the water reaching a well near the center of the well field was derived from the river. The estimated streambed-leakance values are compatible with other aquifer properties and with hydraulic stresses observed over a 2-year period, as demonstrated by a set of six alternative groundwater flow models of the Rockaway River valley. Simulated water levels rose 0.5 to 1.7 feet near the well field when simulated streambed leakance was changed from 0.2 to 0.6 feet per day per foot, or when a former reach of the Rockaway River valley that is now blocked by glacial drift was simulated as containing a continuous sand aquifer (rather than impermeable till). Model recalibration to observed water levels could accommodate either of these changes, however, by plausible adjustments in hydraulic conductivity of 35 percent or less.The ground-water flow models incorporate a new procedure for simulating areal recharge, in which water available for recharge in any time interval is accepted as recharge only where the water level in the uppermost model layer is below land surface. Water rejected as recharge on upland hillsides is allowed to recharge

  16. Processing, Analysis, and General Evaluation of Well-Driller Logs for Estimating Hydrogeologic Parameters of the Glacial Sediments in a Ground-Water Flow Model of the Lake Michigan Basin

    Science.gov (United States)

    Arihood, Leslie D.

    2009-01-01

    In 2005, the U.S. Geological Survey began a pilot study for the National Assessment of Water Availability and Use Program to assess the availability of water and water use in the Great Lakes Basin. Part of the study involves constructing a ground-water flow model for the Lake Michigan part of the Basin. Most ground-water flow occurs in the glacial sediments above the bedrock formations; therefore, adequate representation by the model of the horizontal and vertical hydraulic conductivity of the glacial sediments is important to the accuracy of model simulations. This work processed and analyzed well records to provide the hydrogeologic parameters of horizontal and vertical hydraulic conductivity and ground-water levels for the model layers used to simulated ground-water flow in the glacial sediments. The methods used to convert (1) lithology descriptions into assumed values of horizontal and vertical hydraulic conductivity for entire model layers, (2) aquifer-test data into point values of horizontal hydraulic conductivity, and (3) static water levels into water-level calibration data are presented. A large data set of about 458,000 well driller well logs for monitoring, observation, and water wells was available from three statewide electronic data bases to characterize hydrogeologic parameters. More than 1.8 million records of lithology from the well logs were used to create a lithologic-based representation of horizontal and vertical hydraulic conductivity of the glacial sediments. Specific-capacity data from about 292,000 well logs were converted into horizontal hydraulic conductivity values to determine specific values of horizontal hydraulic conductivity and its aerial variation. About 396,000 well logs contained data on ground-water levels that were assembled into a water-level calibration data set. A lithology-based distribution of hydraulic conductivity was created by use of a computer program to convert well-log lithology descriptions into aquifer or

  17. 40 CFR 257.22 - Ground-water monitoring systems.

    Science.gov (United States)

    2010-07-01

    ... operator. When physical obstacles preclude installation of ground-water monitoring wells at the relevant... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water monitoring systems. 257... Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.22 Ground-water......

  18. Estimating the Ground Water Resources of Atoll Islands

    Directory of Open Access Journals (Sweden)

    Arne E. Olsen

    2010-01-01

    Full Text Available Ground water resources of atolls, already minimal due to the small surface area and low elevation of the islands, are also subject to recurring, and sometimes devastating, droughts. As ground water resources become the sole fresh water source when rain catchment supplies are exhausted, it is critical to assess current groundwater resources and predict their depletion during drought conditions. Several published models, both analytical and empirical, are available to estimate the steady-state freshwater lens thickness of small oceanic islands. None fully incorporates unique shallow geologic characteristics of atoll islands, and none incorporates time-dependent processes. In this paper, we provide a review of these models, and then present a simple algebraic model, derived from results of a comprehensive numerical modeling study of steady-state atoll island aquifer dynamics, to predict the ground water response to changes in recharge on atoll islands. The model provides an estimate thickness of the freshwater lens as a function of annual rainfall rate, island width, Thurber Discontinuity depth, upper aquifer hydraulic conductivity, presence or absence of a confining reef flat plate, and in the case of drought, time. Results compare favorably with published atoll island lens thickness observations. The algebraic model is incorporated into a spreadsheet interface for use by island water resources managers.

  19. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    Directory of Open Access Journals (Sweden)

    Yu. P. Sedlukho

    2015-01-01

    Full Text Available The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation. In addition to this violation of sulfide-carbonate equilibrium taking place in the process of aeration due to desorption of H2S and CO2, often leads to clogging of degasifier nozzles with formed CaCO3 that causes serious operational problems. Chemical methods require relatively large flow of complex reagent facilities, storage facilities and transportation costs.In terms of hydrogen sulfide ground water purification the greatest interest is given to the biochemical method. Factors deterring widespread application of the biochemical method is its insufficient previous investigation and necessity to execute special research in order to determine optimal process parameters while purifying groundwater of a particular water supply source. Biochemical methods for oxidation of sulfur compounds are based on natural biological processes that ensure natural sulfur cycle. S. Vinogradsky has established a two-stage mechanism for oxidation of hydrogen sulfide with sulfur bacteria (Beggiatoa. The first stage presupposes oxidation of hydrogen sulphide to elemental sulfur which is accumulating in the cytoplasm in the form of globules. During the second stage sulfur bacteria begin to oxidize intracellular sulfur to sulfuric acid due to shortage of hydrogen sulfide.The paper provides the results of technological tests of large-scale pilot plants for biochemical purification of groundwater from hydrogen sulfide in semi-industrial conditions. Dependences of water quality

  20. Factors influencing ground-water recharge in the eastern United States

    Science.gov (United States)

    Nolan, B.T.; Healy, R.W.; Taber, P.E.; Perkins, K.; Hitt, K.J.; Wolock, D.M.

    2007-01-01

    Ground-water recharge estimates for selected locations in the eastern half of the United States were obtained by Darcian and chloride-tracer methods and compared using statistical analyses. Recharge estimates derived from unsaturated-zone (RUZC) and saturated-zone (RSZC) chloride mass balance methods are less variable (interquartile ranges or IQRs are 9.5 and 16.1 cm/yr, respectively) and more strongly correlated with climatic, hydrologic, land use, and sediment variables than Darcian estimates (IQR = 22.8 cm/yr). The unit-gradient Darcian estimates are a nonlinear function of moisture content and also reflect the uncertainty of pedotransfer functions used to estimate hydraulic parameters. Significance level is 0.3. Estimates of RSZC were evaluated using analysis of variance, multiple comparison tests, and an exploratory nonlinear regression (NLR) model. Recharge generally is greater in coastal plain surficial aquifers, fractured crystalline rocks, and carbonate rocks, or in areas with high sand content. Westernmost portions of the study area have low recharge, receive somewhat less precipitation, and contain fine-grained sediment. The NLR model simulates water input to the land surface followed by transport to ground water, depending on factors that either promote or inhibit water infiltration. The model explains a moderate amount of variation in the data set (coefficient of determination = 0.61). Model sensitivity analysis indicates that mean annual runoff, air temperature, and precipitation, and an index of ground-water exfiltration potential most influence estimates of recharge at sampled sites in the region. Soil characteristics and land use have less influence on the recharge estimates, but nonetheless are significant in the NLR model. ?? 2006 Elsevier B.V. All rights reserved.

  1. Estimation of ground water hydraulic parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hvilshoej, Soeren

    1998-11-01

    The main objective was to assess field methods to determine ground water hydraulic parameters and to develop and apply new analysis methods to selected field techniques. A field site in Vejen, Denmark, which previously has been intensively investigated on the basis of a large amount of mini slug tests and tracer tests, was chosen for experimental application and evaluation. Particular interest was in analysing partially penetrating pumping tests and a recently proposed single-well dipole test. Three wells were constructed in which partially penetrating pumping tests and multi-level single-well dipole tests were performed. In addition, multi-level slug tests, flow meter tests, gamma-logs, and geologic characterisation of soil samples were carried out. In addition to the three Vejen analyses, data from previously published partially penetrating pumping tests were analysed assuming homogeneous anisotropic aquifer conditions. In the present study methods were developed to analyse partially penetrating pumping tests and multi-level single-well dipole tests based on an inverse numerical model. The obtained horizontal hydraulic conductivities from the partially penetrating pumping tests were in accordance with measurements obtained from multi-level slug tests and mini slug tests. Accordance was also achieved between the anisotropy ratios determined from partially penetrating pumping tests and multi-level single-well dipole tests. It was demonstrated that the partially penetrating pumping test analysed by and inverse numerical model is a very valuable technique that may provide hydraulic information on the storage terms and the vertical distribution of the horizontal and vertical hydraulic conductivity under both confined and unconfined aquifer conditions. (EG) 138 refs.

  2. Ground-water provinces of southern Rhodesia

    Science.gov (United States)

    Dennis, Philip Eldon; Hindson, L.L.

    1964-01-01

    Ground-water development, utilization, and occurrence in nine ground-water provinces of Southern Rhodesia are summarized in this report. Water obtained from drilled wells for domestic and stock use has played an important part in the social and economic development of Southern Rhodesia from the beginnings of European settlement to the present. Most of the wells obtain water from fractures and weathered zones in crystalline rocks, before recently, there has been an interest in the possibility of obtaining water for irrigation from wells. Studies of the authors indicate that quantities of water sufficient for irrigation can be obtained from alluvial sediments in the S'abi Valley, from Kalahari sands in the western part of the country, are perhaps from aquifers in other areas. The ground-water provinces fall into two groups--those in the crystalline rocks and those in the noncrystalline rocks. Historically, the wells in crystalline rocks, especially the Gold belts province and the Intrusive granites province, have played a major role in supplying water for the needs of man. These provinces, together with two other less important crystalline rock provinces, form the broad arch which constitutes the central core of the country. The noncrystalline rocks overlie and flank the crystalline rocks to the southeast, northwest, and north. The noncrystalline rock provinces, especially the Alluvium-Kalahari province, contain the most productive or potentially productive ground-water reservoirs in Southern Rhodesia and offer promise of supplying water for irrigation and for other purposes.

  3. Magnificent Ground Water Connection. [Sample Activities].

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    Water conservation and usage is an important concept in science. This document, geared specifically to New England, provides many activities for protecting and discussing ground water situations. Sample activities for grades K-6 include: (1) All the Water in the World; (2) The Case of the Disappearing Water; (3) Deep Subjects--Wells and Ground…

  4. Depth to ground water of Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a raster-based, depth to ground-water data set for the State of Nevada. The source of this data set is a statewide water-table contour data set constructed...

  5. Ground-water contribution to dose from past Hanford Operations. Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Freshley, M.D.; Thorne, P.D.

    1992-08-01

    The Hanford Environmental Dose Reconstruction (HEDR) Project is being conducted to estimate radiation doses that populations and individuals could have received from Hanford Site operations from 1944 to the present. Four possible pathways by which radionuclides migrating in ground water on the Hanford Site could have reached the public have been identified: (1) through contaminated ground water migrating to the Columbia River; (2) through wells on or adjacent to the Hanford Site; (3) through wells next to the Columbia River downstream of Hanford that draw some or all of their water from the river (riparian wells); and (4) through atmospheric deposition resulting in contamination of a small watershed that, in turn, results in contamination of a shallow well or spring by transport in the ground water. These four pathways make up the ``ground-water pathway,`` which is the subject of this study. Assessment of the ground-water pathway was performed by (1) reviewing the existing extensive literature on ground water and ground-water monitoring at Hanford and (2) performing calculations to estimate radionuclide concentrations where no monitoring data were collected. Radiation doses that would result from exposure to these radionuclides were calculated.

  6. Salinization of a fresh palaeo-ground water resource by enhanced recharge.

    Science.gov (United States)

    Leaney, F W; Herczeg, A L; Walker, G R

    2003-01-01

    Deterioration of fresh ground water resources caused by salinization is a growing issue in many arid and semi-arid parts of the world. We discuss here the incipient salinization of a 10(4) km2 area of fresh ground water (Ground water 14C concentrations and unsaturated zone Cl soil water inventories indicate that the low salinity ground water originated mainly from palaeo-recharge during wet climatic periods more than 20,000 years ago. However, much of the soil water in the 20 to 60 m thick unsaturated zone throughout the area is generally saline (>15,000 mg/L) because of relatively high evapotranspiration during the predominantly semiarid climate of the last 20,000 years. Widespread clearing of native vegetation over the last 100 years and replacement with crops and pastures leads to enhancement of recharge rates that progressively displace the saline soil-water from the unsaturated zone into the ground water. To quantify the impact of this new hydrologic regime, a one-dimensional model that simulates projected ground water salinities as a function of depth to ground water, recharge rates, and soil water salt inventory was developed. Results from the model suggest that, in some areas, the ground water salinity within the top 10 m of the water table is likely to increase by a factor of 2 to 6 during the next 100 years. Ground water quality will therefore potentially degrade beyond the point of usefulness well before extraction of the ground water exhausts the resource.

  7. Isotopic composition of ground waters from Kufra (Lybia) as indicator for ground water formation

    Energy Technology Data Exchange (ETDEWEB)

    Swailem, F.M.; Hamza, M.S.; Aly, A.I.M. (Middle Eastern Regional Radioisotope Centre for the Arab Countries, Cairo (Egypt))

    1984-02-01

    The results of the isotopic composition of shallow and deep ground waters from the Kufra region indicate the fossil origin of these waters and that they are not recharged under the present climatic conditions. The virtual absence of tritium and the radiocarbon ages of these waters show that they were formed mainly in the past pluvial periods. Deuterium and oxygen-18 data indicate that the ground waters were recharged under cooler climatic conditions. These results may explain the origin of the large amounts of ground water which existed in the region.

  8. Probability of nitrate contamination of recently recharged ground waters in the conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a national map of predicted probability of nitrate contamination of shallow ground waters based on a logistic regression (LR) model. The LR model...

  9. A FIXED BED SORPTION SYSTEM FOR DEFLUORIDATION OF GROUND WATER

    Directory of Open Access Journals (Sweden)

    Ayoob Sulaiman

    2009-06-01

    Full Text Available The presence of excess fluoride in ground water has become a global threat with as many as 200 million people affected in more than 35 countries in all the continents. Of late, there have been significant advances in the knowledge base regarding the effects of excess fluoride on human health. As a result, defluoridation of ground water is regarded as one of the key areas of attention among the universal water community triggering global research. This study describes the sorptive responses of a newly developed adsorbent, alumina cement granules (ALC, in its real-life application in fixed beds, for removing fluoride from the ground waters of a rural Indian village. ALC exhibited almost consistent scavenging capacity at various bed depths in column studies with an enhanced adsorption potential of 0.818 mg/g at a flow rate of 4 ml/min. The Thomas model was examined to describe the sorption process. The process design parameters of the column were obtained by linear regression of the model. In all the conditions examined, the Thomas model could consistently predict its characteristic parameters and describe the breakthrough sorption profiles in the whole range of sorption process.

  10. EFFECT OF NATURAL AND COMMERCIAL SURFACTANTS ON THE SURVIVAL AND SORPTION OF BACTERIOPHAGES IN GROUND WATER SYSTEMS

    Science.gov (United States)

    There is an increasing concern about the protection of ground water from contamination by enteric viruses and the prevention of outbreaks of waterborne diseases. This study was undertaken to determine the processes that control viral transport in soil and ground water. In this ...

  11. EFFECT OF NATURAL AND COMMERCIAL SURFACTANTS ON THE SURVIVAL AND SORPTION OF BACTERIOPHAGES IN GROUND WATER SYSTEMS

    Science.gov (United States)

    There is an increasing concern about the protection of ground water from contamination by enteric viruses and the prevention of outbreaks of waterborne diseases. This study was undertaken to determine the processes that control viral transport in soil and ground water. In this ...

  12. Ground water discharge and the related nutrient and trace metal fluxes into Quincy Bay, Massachusetts

    Science.gov (United States)

    Poppe, L.J.; Moffett, A.M.

    1993-01-01

    Measurement of the rate and direction of ground water flow beneath Wollaston Beach, Quincy, Massachusetts by use of a heat-pulsing flowmeter shows a mean velocity in the bulk sediment of 40 cm d-1. The estimated total discharge of ground water into Quincy Bay during October 1990 was 1324-2177 m3 d-1, a relatively low ground Water discharge rate. The tides have only a moderate effect on the rate and direction of this flow. Other important controls on the rate and volume of ground water flow are the limited thickness, geographic extent, and permeability of the aquifer. Comparisons of published streamflow data and estimates of ground water discharge indicate that ground water makes up between 7.4-12.1% of the gaged freshwater input into Quincy Bay. The data from this study suggest the ground water discharge is a less important recharge component to Quincy Bay than predicted by National Urban Runoff Program (NURP) models. The high nitrate and low nitrite and ammonia concentrations in the ground water at the backshore we]l sites and low nitrate and high nitrite and ammonia concentrations in the water flowing from the foreshore suggests that denitrification is active in the sediments. The low ground water flow rates and low nitrate concentrations in the foreshore samples suggest that little or no nitrate is surviving the denitrification process to affect the planktonic community. Similarly, oxidizing conditions in the aquifer and low trace metal concentrations in the ground water samples suggest that the metals may be precipitating and binding to sedimentary phases before impacting the bay.

  13. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Naturita, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (phase I), and the Ground Water Project (phase II). For the UMTRA Project site located near Naturita, Colorado (the Naturita site), phase I involves the removal of radioactively contaminated soils and materials and their transportation to a disposal site at Union Carbide Corporation`s Upper Burbank Repository at Uravan, Colorado, about 13 road miles (mi) (21 kilometers [km]) to the northwest. No uranium mill tailings are involved because the tailings were removed from the Naturita site and placed at Coke Oven, Colorado, during 1977 to 1979. Phase II of the project will evaluate the nature and extent of ground water contamination resulting from uranium processing and its effect on human health or the environment; and will determine site-specific ground water compliance strategies in accordance with the US Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. Human health risks could occur from drinking water pumped from a hypothetical well drilled in the contaminated ground water area. Environmental risks may result if plants or animals are exposed to contaminated ground water, or surface water that has received contaminated ground water. Therefore, a risk assessment is conducted for the Naturita site. This risk assessment report is the first site-specific document prepared for the Ground Water Project at the Naturita site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine whether any action is needed to protect human health or the environment.

  14. Geohydrology, simulation of ground-water flow, and ground-water quality at two landfills, Marion County, Indiana. Water Resources Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Duwelius, R.F.; Greeman, T.K.

    1989-01-01

    The report presents the results of a study to provide a quantitative evaluation of the ground-water flow system at the Julietta and Tibbs-Banta landfills and provide a general description of the ground-water quality beneath and near the two landfills. These objectives provide the information necessary to evaluate the effects of the landfills on ground-water quality. Geologic, hydrologic, and water-quality data were collected in 1985 and 1986 at the Julietta and Tibbs-Banta landfills to fulfill the study objectives. Ground-water models were used to investigate the flow systems and estimate the volume of flow at the landfills. The report includes descriptions of the data collection, geologic and hydrologic descriptions of the two landfills, and brief histories of trash and sludge disposal. Ground-water-flow models are described and estimates of the volume of flow are discussed. A description of the quality-assurance plan used in conjunction with the water-quality data collection and analysis is included. Water-quality data are presented with statistical summaries of ground-water quality related to well depth and position in the flow system.

  15. Clinoptilolite as an in-situ permeable barrier to strontium migration in ground water

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, K.J.; Martin, P.F.; Szecsody, J.E. [Pacific Northwest Lab., Richland, WA (United States)

    1994-12-31

    Batch adsorption experiments were conducted with three zeolites (clinoptilolite, chabazite, and A-51) to determine their potential applicability as in-situ permeable barriers to ground water strontium migration in the 100-N Area of the Hanford Site. Each of the zeolites was an effective adsorbent for strontium, even in competition with calcium at concentrations typical of Hanford ground water, and the authors determined that clinoptilolite would be the most cost-effective. The strontium adsorption data for calcium-saturated clinoptilolite were fitted to a Langmuir isotherm, which is linear at solution concentrations of less than 10{sup {minus}5} mol/L. In this region, the adsorption coefficient (K{sub d}) was 956 L/kg. Because strontium concentrations in hanford ground water are typically 3 x 10{sup {minus}6} mol/L, assuming linear adsorption (K{sub d} = 956 L/kg) for modeling purposes is appropriate. These data were used to design an effective barrier and were incorporated into a transport model to assess its performance. Calculations indicated that a barrier 1.3 m thick would prevent strontium-90 migration to the Columbia river at 100-N Area for over 50 yr. Because of radioactive decay and adsorption, the maximum breakthrough of strontium-90, approximately 5% of the initial input, would occur at 100 yr. Preliminary experimental work was conducted to determine the adsorption kinetics of strontium on clinoptilolite. A comparison of the adsorption rate of strontium with its residence time (within the barrier) indicates that adsorption kinetics are sufficiently fast that the barrier performance will not be significantly affected.

  16. Artificial Ground Water Recharge with Surface Water

    Science.gov (United States)

    Heviánková, Silvie; Marschalko, Marian; Chromíková, Jitka; Kyncl, Miroslav; Korabík, Michal

    2016-10-01

    With regard to the adverse manifestations of the recent climatic conditions, Europe as well as the world have been facing the problem of dry periods that reduce the possibility of drawing drinking water from the underground sources. The paper aims to describe artificial ground water recharge (infiltration) that may be used to restock underground sources with surface water from natural streams. Among many conditions, it aims to specify the boundary and operational conditions of the individual aspects of the artificial ground water recharge technology. The principle of artificial infiltration lies in the design of a technical system, by means of which it is possible to conduct surplus water from one place (in this case a natural stream) into another place (an infiltration basin in this case). This way, the water begins to infiltrate into the underground resources of drinking water, while the mixed water composition corresponds to the water parameters required for drinking water.

  17. Procedures for ground-water investigations

    Energy Technology Data Exchange (ETDEWEB)

    1989-09-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water investigations are carried out to fulfill the requirements for the US Department of Energy (DOE) to meet the requirements of DOE Orders. Investigations are also performed for various clients to meet the requirements of the Resource Conservation and Recovery Act of 1976 (RCRA) and the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA). National standards including procedures published by the American Society for Testing and Materials (ASTM) and the US Geological Survey were utilized in developing the procedures contained in this manual.

  18. Impacts of Irrigation and Drought on Salem Ground Water

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-06-01

    Full Text Available This investigation is the first of three phases of a ground-water management study. In this report, effects of irrigation and drought on the ground-water resources of Salem are examined. Irrigation water use for five soil types is estimated from a monthly water budget model on the basis of precipitation and temperature data from the last 30 years at selected weather stations across Salem. Moisture deficits are computed for each soil type on the basis of the water requirements of a corn crop. It is assumed that irrigation is used to make up the moisture deficit in those places where irrigation systems already exist. Irrigation water use from each township with irrigated acreage is added to municipal and industrial ground-water use data and then compared to aquifer potential yields. The spatial analysis is accomplished with a statewide geographic information system. An important distinction is made between the seasonal effects of irrigation water use and the annual or long-term effects.

  19. Detection of Ground Water Availability at Buhias Island, Sitaro Regency

    Directory of Open Access Journals (Sweden)

    Zetly E Tamod

    2016-08-01

    Full Text Available The study aims to detect ground water availability at Buhias Island, Siau Timur Selatan District, Sitaro Regency. The research method used the survey method by geoelectrical instrument based on subsurface rock resistivity as a geophysical exploration results with geoelectrical method of Wenner-Schlumberger configuration. Resistivity geoelectrical method is done by injecting a flow into the earth surface, then it is measured the potential difference. This study consists of 4 tracks in which each track is made the stretch model of soil layer on subsurface of ground.  Then, the exploration results were processed using software RES2DINV to look at the data of soil layer based on the value of resistivity (2D. Interpretation result of the track 1 to 4 concluded that there is a layer of ground water. State of dominant ground water contains the saline (brackish. Location of trajectory in the basin to the lowland areas is mostly mangrove swamp vegetation. That location is the junction between the results of the runoff of rainfall water that falls down from the hills with sea water. Bedrock as a constituent of rock layer formed from marine sediments that carry minerals salts.

  20. SITE-94. Geochemical characterization of Simpevarp ground waters near the Aespoe Hard Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Glynn, P.D.; Voss, C.I. [US Geological Survey, Reston, VA (United States)

    1999-09-01

    possible range of values that need to be considered. Tritium measurements confirm that the recent ground water type, originally identified on the basis of deuterium and chloride measurements, contains a significant proportion of recent, post-1950, water. Better tritium analyses, together with a greater number of carbon-13 analyses on dissolved inorganic carbon, would have helped interpret the carbon-14 analyses that were obtained primarily from relatively shallow ground waters (< 500 m depth). The SITE-94 Central Scenario climate model suggests that three glaciations may occur in the Northern Hemisphere during the next 120,000 years. If such glaciations do occur, possible climate-driven changes in ground-water geochemistry, particularly in redox conditions, could occur in the Fennoscandian shield. During two of these glaciations, 2- to3-km high ice sheets are predicted to form over the Fennoscandian shield, extending over Aespoe island and further south. Modeling of ground-water flow and transport suggests the possibility of deep and fast penetration of glacial melt waters during periods of glacial advance. The intruding melt waters have a median travel time of less than 100 years to 500 m depth. Ice composition data from the base of the Greenland ice sheet suggests that the melt waters will be highly enriched in dissolved oxygen, with concentrations at least 3 to 5 times higher than would be obtained at atmospheric equilibrium. The relative scarcity of fast-reacting pyrite in hydraulically conductive fractures, and the expected scarcity of organic carbon that would be exposed to the intruding melt waters, implies that Fe(II)-rich silicate minerals would be the primary reductants for the intruding dissolved oxygen. Current information suggests that the reaction rates would not be sufficiently fast to prevent penetration of oxygenated melt waters to a depth of at least 500 m. Despite clear evidence of past, deep, glacial meltwater penetration, convincing geochemical

  1. Nitrate Removal from Ground Water: A Review

    OpenAIRE

    Archna *; Surinder K. Sharma; Ranbir Chander Sobti

    2012-01-01

    Nitrate contamination of ground water resources has increased in Asia, Europe, United States, and various other parts of the world. This trend has raised concern as nitrates cause methemoglobinemia and cancer. Several treatment processes can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation. Available technical data, experience, and economics indicate that biological denitrification is more acceptable for nitrate removal than reverse osmosis and ion ex...

  2. Ground water and the rural homeowner

    Science.gov (United States)

    Waller, Roger M.

    1994-01-01

    As the salesmen sang in the musical The Music Man, "You gotta know the territory." This saying is also true when planning to buy or build a house. Learn as much as possible about the land, the water supply, and the septic system of the house before buying or building. Do not just look at the construction aspects or the beauty of the home and surroundings. Be sure to consider the environmental conditions around and beneath the site as well. Try to visit the site under adverse conditions, such as during heavy rain or meltwater runoff, to observe the drainage characteristics, particularly the condition of the basement. Many of the conditions discussed in this book, such as lowered well-water levels, flooded basements, and contamination from septic systems, are so common that rural families often have to deal with one or more of them. The purpose of this book is to awaken an interest in ground water and an awareness of where it is available, how it moves, how people can adjust to its patterns to avoid problems, and how it can be protected and used wisely. This booklet provides both present and prospective rural homeowners, particularly those in the glaciated northern parts of the United States, with a basic but comprehensive description of ground water. It also presents problems one may expect to encounter with ground water and some solutions or suggestions for help with these problems.

  3. Boundary of the hydrogeologic framework model by IT Corporation (1996), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the hydrogeologic framework model (HFM) developed by IT Corporation (1996) for the U.S. Department of Energy...

  4. Three-dimensional model simulation of steady-state ground-water flow in the Albuquerque-Belen Basin, New Mexico

    Science.gov (United States)

    Kernodle, J.M.; Scott, W.B.

    1986-01-01

    As part of the Southwest Alluvial Basins study, model was constructed to simulate the alluvial aquifer system underlying the Albuquerque-Belen Basin. The model was used to simulate the steady-state flow condition assumed to have existed prior to 1960. Until this time there apparently were no long-term groundwater level changes of a significant magnitude outside the immediate vicinity of Albuquerque. Therefore, the construction of a steady-state flow model of the aquifer system based on reported hydrologic data predating 1960 was justified. During construction of the steady-state model, simulated hydraulic conductivity values were adjusted, within acceptable physical limits, until a best fit between measured or reported and computed heads at 34 control wells was achieved. The modeled area was divided into six sub-areas, or zones, within each of which hydraulic conductivity was assumed to be uniform. The model consisted of six layers for each of which simulated transmissivity was proportional to the layer thickness. Adjustments to simulated hydraulic conductivity values in the different zones resulted in final values that ranged from a low of 0.25 ft/day in the west to 50 ft/day in the eastern part of the basin. The error of the simulation, defined as the absolute difference between the computed and the measured or reported water level at the corresponding point in the physical system being modeled, ranged from 0.6 ft to 36 ft, with an average of 14.6 ft for the 34 control wells. (Author 's abstract)

  5. Hydrogeologic Setting and Ground-Water Flow in the Leetown Area, West Virginia

    Science.gov (United States)

    Kozar, Mark D.; Weary, David J.; Paybins, Katherine S.; Pierce, Herbert A.

    2007-01-01

    The Leetown Science Center is a research facility operated by the U.S. Geological Survey that occupies approximately 455-acres near Kearneysville, Jefferson County, West Virginia. Aquatic and fish research conducted at the Center requires adequate supplies of high-quality, cold ground water. Three large springs and three production wells currently (in 2006) supply water to the Center. The recent construction of a second research facility (National Center for Cool and Cold Water Aquaculture) operated by the U.S. Department of Agriculture and co-located on Center property has placed additional demands on available water resources in the area. A three-dimensional steady-state finite-difference ground-water flow model was developed to simulate ground-water flow in the Leetown area and was used to assess the availability of ground water to sustain current and anticipated future demands. The model also was developed to test a conceptual model of ground-water flow in the complex karst aquifer system in the Leetown area. Due to the complexity of the karst aquifer system, a multidisciplinary research study was required to define the hydrogeologic setting. Geologic mapping, surface- and borehole-geophysical surveys, stream base-flow surveys, and aquifer tests were conducted to provide the hydrogeologic data necessary to develop and calibrate the model. It would not have been possible to develop a numerical model of the study area without the intensive data collection and methods developments components of the larger, more comprehensive hydrogeologic investigation. Results of geologic mapping and surface-geophysical surveys verified the presence of several prominent thrust faults and identified additional faults and other complex geologic structures (including overturned anticlines and synclines) in the area. These geologic structures are known to control ground-water flow in the region. Results of this study indicate that cross-strike faults and fracture zones are major

  6. Assessment of ground water pollution in the residential areas of ...

    African Journals Online (AJOL)

    Assessment of ground water pollution in the residential areas of Ewekoro and Shagamu ... of the ground water distribution of the settlements around cement factories in ... The concentrations of lead and cadmium are above the World Health ...

  7. Simulation of regional ground-water flow in the Upper Deschutes Basin, Oregon

    Science.gov (United States)

    Gannett, Marshall W.; Lite, Kenneth E.

    2004-01-01

    This report describes a numerical model that simulates regional ground-water flow in the upper Deschutes Basin of central Oregon. Ground water and surface water are intimately connected in the upper Deschutes Basin and most of the flow of the Deschutes River is supplied by ground water. Because of this connection, ground-water pumping and reduction of artificial recharge by lining leaking irrigation canals can reduce the amount of ground water discharging to streams and, consequently, streamflow. The model described in this report is intended to help water-management agencies and the public evaluate how the regional ground-water system and streamflow will respond to ground-water pumping, canal lining, drought, and other stresses. Ground-water flow is simulated in the model by the finite-difference method using MODFLOW and MODFLOWP. The finite-difference grid consists of 8 layers, 127 rows, and 87 columns. All major streams and most principal tributaries in the upper Deschutes Basin are included. Ground-water recharge from precipitation was estimated using a daily water-balance approach. Artificial recharge from leaking irrigation canals and on-farm losses was estimated from diversion and delivery records, seepage studies, and crop data. Ground-water pumpage for irrigation and public water supplies, and evapotranspiration are also included in the model. The model was calibrated to mean annual (1993-95) steady-state conditions using parameter-estimation techniques employing nonlinear regression. Fourteen hydraulic-conductivity parameters and two vertical conductance parameters were determined using nonlinear regression. Final parameter values are all within expected ranges. The general shape and slope of the simulated water-table surface and overall hydraulic-head distribution match the geometry determined from field measurements. The fitted standard deviation for hydraulic head is about 76 feet. The general magnitude and distribution of ground-water discharge to

  8. Ground-water, surface-water, and bottom-sediment contamination in the O-field area, Aberdeen Proving Ground, Maryland, and the possible effects of selected remedial actions on ground water

    Science.gov (United States)

    Vroblesky, Don A.; Lorah, Michelle M.; Oliveros, James P.

    1995-01-01

    Disposal of munitions and chemical-warfare substances has introduced inorganic and organic contaminants to the ground water, surface water, and bottom sediment at O-Field, in the Edgewood area of Aberdeen Proving Ground, Maryland. Contaminants include chloride, arsenic, transition metals, chlorinated aliphatic hydrocarbons, aromatic compounds, and organosulfur and organophosphorus compounds. The hydrologic effects of several remedial actions were estimated by use of a ground-water-flow model. The remedial actions examined were an impermeable covering, encapsulation, subsurface barriers, a ground-water drain, pumping of wells to manage water levels or to remove contaminated ground water for treatment, and no action.

  9. Denitrification in the shallow ground water of a tile-drained, agricultural watershed

    Science.gov (United States)

    Mehnert, E.; Hwang, H.-H.; Johnson, T.M.; Sanford, R.A.; Beaumont, W.C.; Holm, T.R.

    2007-01-01

    Nonpoint-source pollution of surface water by N is considered a major cause of hypoxia. Because Corn Belt watersheds have been identified as major sources of N in the Mississippi River basin, the fate and transport of N from midwestern agricultural watersheds have received considerable interest. The fate and transport of N in the shallow ground water of these watersheds still needs additional research. Our purpose was to estimate denitrification in the shallow ground water of a tile-drained, Corn Belt watershed with fine-grained soils. Over a 3-yr period, N was monitored in the surface and ground water of an agricultural watershed in central Illinois. A significant amount of N was transported past the tile drains and into shallow ground water. The ground water nitrate was isotopically heavier than tile drain nitrate, which can be explained by denitrification in the subsurface. Denitrifying bacteria were found at depths to 10 m throughout the watershed. Laboratory and push-pull tests showed that a significant fraction of nitrate could be denitrified rapidly. We estimated that the N denitrified in shallow ground water was equivalent to 0.3 to 6.4% of the applied N or 9 to 27% of N exported via surface water. These estimates varied by water year and peaked in a year of normal precipitation after 2 yr of below average precipitation. Three years of monitoring data indicate that shallow ground water in watersheds with fine-grained soils may be a significant N sink compared with N exported via surface water. ?? ASA, CSSA, SSSA.

  10. 40 CFR 258.51 - Ground-water monitoring systems.

    Science.gov (United States)

    2010-07-01

    ... preclude installation of ground-water monitoring wells at the relevant point of compliance at existing... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water monitoring systems. 258... CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.51...

  11. Ground-water surveillance at the Hanford Site for CY 1983

    Energy Technology Data Exchange (ETDEWEB)

    Prater, L.S.; Rieger, J.T.; Cline, C.S.; Jensen, E.J.; Liikala, T.L.; Oster, K.R.

    1984-07-01

    Operations at the Hanford Site have resulted in the discharge of large volumes of process cooling water and other waste waters to the ground. These effluents contain low level of radioactive and chemical substances. During 1983, 328 monitoring wells were sampled at various times for radioactive and chemical constituents. Three of these constituents, specifically tritium, nitrate, and gross beta activity, were selected for detailed discussion in this report because they are more readily transported in the ground water than some of the other constituents. Transport of these constituents in the ground water has resulted in the formation of plumes that can be mapped by contouring the analytical data obtained from the monitoring wells. This report describes recent changes in the configuration of the tritium, nitrate and gross beta plumes. Changes or trends in contaminant levels in wells located within both the main plumes (originating from the 200 Areas) and the smaller plumes are discussed in this report. Two potential pathways for radionuclide transport from the ground water to the environmental are discussed in this report, and the radiological impacts are examined. In addition to describing the present status of the ground water beneath the Hanford Site, this report contains the results of studies conducted in support of the ground-water surveillance effort during CY 1983. 21 references, 26 figures, 5 tables.

  12. Development of a Ground Water Data Portal for Interoperable Data Exchange within the U.S. National Ground Water Monitoring Network and Beyond

    Science.gov (United States)

    Booth, N. L.; Brodaric, B.; Lucido, J. M.; Kuo, I.; Boisvert, E.; Cunningham, W. L.

    2011-12-01

    The need for a national groundwater monitoring network within the United States is profound and has been recognized by organizations outside government as a major data gap for managing ground-water resources. Our country's communities, industries, agriculture, energy production and critical ecosystems rely on water being available in adequate quantity and suitable quality. To meet this need the Subcommittee on Ground Water, established by the Federal Advisory Committee on Water Information, created a National Ground Water Monitoring Network (NGWMN) envisioned as a voluntary, integrated system of data collection, management and reporting that will provide the data needed to address present and future ground-water management questions raised by Congress, Federal, State and Tribal agencies and the public. The NGWMN Data Portal is the means by which policy makers, academics and the public will be able to access ground water data through one seamless web-based application from disparate data sources. Data systems in the United States exist at many organizational and geographic levels and differing vocabulary and data structures have prevented data sharing and reuse. The data portal will facilitate the retrieval of and access to groundwater data on an as-needed basis from multiple, dispersed data repositories allowing the data to continue to be housed and managed by the data provider while being accessible for the purposes of the national monitoring network. This work leverages Open Geospatial Consortium (OGC) data exchange standards and information models. To advance these standards for supporting the exchange of ground water information, an OGC Interoperability Experiment was organized among international participants from government, academia and the private sector. The experiment focused on ground water data exchange across the U.S. / Canadian border. WaterML2.0, an evolving international standard for water observations, encodes ground water levels and is exchanged

  13. Characterization of Climax granite ground water

    Energy Technology Data Exchange (ETDEWEB)

    Isherwood, D.; Harrar, J.; Raber, E.

    1982-08-01

    The Climax ground water fails to match the commonly held views regarding the nature of deep granitic ground waters. It is neither dilute nor in equilibrium with the granite. Ground-water samples were taken for chemical analysis from five sites in the fractured Climax granite at the Nevada Test Site. The waters are high in total dissolved solids (1200 to 2160 mg/L) and rich in sodium (56 to 250 mg/L), calcium (114 to 283 mg/L) and sulfate (325 to 1060 mg/L). Two of the samples contained relatively high amounts of uranium (1.8 and 18.5 mg/L), whereas the other three contained uranium below the level of detection (< 0.1 mg/L). The pH is in the neutral range (7.3 to 8.2). The differences in composition between samples (as seen in the wide range of values for the major constituents and total dissolved solids) suggest the samples came from different, independent fracture systems. However, the apparent trend of increasing sodium with depth at the expense of calcium and magnesium suggests a common evolutionary chemical process, if not an interconnected system. The waters appear to be less oxidizing with depth (+ 410 mV at 420 m below the surface vs + 86 mV at 565 m). However, with Eh measurements on only two samples, this correlation is questionable. Isotopic analyses show that the waters are of meteoric origin and that the source of the sulfate is probably the pyrite in the fracture-fill material. Analysis of the measured water characteristics using the chemical equilibrium computer program EQ3 indicates that the waters are not in equilibrium with the local mineral assemblage. The solutions appear to be supersaturated with respect to the mineral calcite, quartz, kaolinite, muscovite, k-feldspar, and many others.

  14. Risk evaluation of ground water table decline as a type of desertification. A case study are: Southern Iran

    Energy Technology Data Exchange (ETDEWEB)

    Asrari, E.; Masoudi, M.

    2009-07-01

    This paper presents a model to assess risk of ground water table decline. Taking into consideration eleven indicators of lowering of ground water table the model identifies areas with Potential Risk (risky zones) and areas of Actual risk as well as projects the probability of the worse degradation in future. (Author) 7 refs.

  15. An Excel Workbook for Identifying Redox Processes in Ground Water

    Science.gov (United States)

    Jurgens, Bryant C.; McMahon, Peter B.; Chapelle, Francis H.; Eberts, Sandra M.

    2009-01-01

    The reduction/oxidation (redox) condition of ground water affects the concentration, transport, and fate of many anthropogenic and natural contaminants. The redox state of a ground-water sample is defined by the dominant type of reduction/oxidation reaction, or redox process, occurring in the sample, as inferred from water-quality data. However, because of the difficulty in defining and applying a systematic redox framework to samples from diverse hydrogeologic settings, many regional water-quality investigations do not attempt to determine the predominant redox process in ground water. Recently, McMahon and Chapelle (2008) devised a redox framework that was applied to a large number of samples from 15 principal aquifer systems in the United States to examine the effect of redox processes on water quality. This framework was expanded by Chapelle and others (in press) to use measured sulfide data to differentiate between iron(III)- and sulfate-reducing conditions. These investigations showed that a systematic approach to characterize redox conditions in ground water could be applied to datasets from diverse hydrogeologic settings using water-quality data routinely collected in regional water-quality investigations. This report describes the Microsoft Excel workbook, RedoxAssignment_McMahon&Chapelle.xls, that assigns the predominant redox process to samples using the framework created by McMahon and Chapelle (2008) and expanded by Chapelle and others (in press). Assignment of redox conditions is based on concentrations of dissolved oxygen (O2), nitrate (NO3-), manganese (Mn2+), iron (Fe2+), sulfate (SO42-), and sulfide (sum of dihydrogen sulfide [aqueous H2S], hydrogen sulfide [HS-], and sulfide [S2-]). The logical arguments for assigning the predominant redox process to each sample are performed by a program written in Microsoft Visual Basic for Applications (VBA). The program is called from buttons on the main worksheet. The number of samples that can be analyzed

  16. Community Sediment Transport Model

    Science.gov (United States)

    2007-01-01

    are used to determine that model results are consistent across compilers, platforms, and computer architectures , and to ensure that changes in code do...Mississippi State University: Bhate During the early months of this project, the focus was on understanding ROMS-CSTM model, architecture , and...Marchesiello, J.C. McWilliams, & K.D. Stolzenbach, 2007: Sediment transport modeling on Southern Californian shelves: A ROMS case study. Continental

  17. Hydrogeology and simulation of regional ground-water-level declines in Monroe County, Michigan

    Science.gov (United States)

    Reeves, Howard W.; Wright, Kirsten V.; Nicholas, J.R.

    2004-01-01

    Observed ground-water-level declines from 1991 to 2003 in northern Monroe County, Michigan, are consistent with increased ground-water demands in the region. In 1991, the estimated ground-water use in the county was 20 million gallons per day, and 80 percent of this total was from quarry dewatering. In 2001, the estimated ground-water use in the county was 30 million gallons per day, and 75 percent of this total was from quarry dewatering. Prior to approximately 1990, the ground-water demands were met by capturing natural discharge from the area and by inducing leakage through glacial deposits that cover the bedrock aquifer. Increased ground-water demand after 1990 led to declines in ground-water level as the system moves toward a new steady-state. Much of the available natural discharge from the bedrock aquifer had been captured by the 1991 conditions, and the response to additional withdrawals resulted in the observed widespread decline in water levels. The causes of the observed declines were explored through the use of a regional ground-water-flow model. The model area includes portions of Lenawee, Monroe, Washtenaw, and Wayne Counties in Michigan, and portions of Fulton, Henry, and Lucas Counties in Ohio. Factors, including lowered water-table elevations because of below average precipitation during the time period (1991 - 2001) and reduction in water supply to the bedrock aquifer because of land-use changes, were found to affect the regional system, but these factors did not explain the regional decline. Potential ground-water capture for the bedrock aquifer in Monroe County is limited by the low hydraulic conductivity of the overlying glacial deposits and shales and the presence of dense saline water within the bedrock as it dips into the Michigan Basin to the west and north of the county. Hydrogeologic features of the bedrock and the overlying glacial deposits were included in the model design. An important step of characterizing the bedrock aquifer was the

  18. Interaction of ground water with the Rock River near Byron, Illinois

    Science.gov (United States)

    Avery, C.F.

    1994-01-01

    Ground-water discharge to the Rock River in the study area, estimated by three independent methods, ranged from 16,300 to 30,900 cubic feet per day; the low value, determined by the use of the modified Darcy equation, is an estimate only of ground-water discharge from the southern side of the Rock River. The vertical distribution of trichloroethene (TCE) in ground water was determined at a test hole along the estimated centerline of the contaminant plume and as close to the river as property access would allow. The maximum concentrations of TCE of 3 micro- grams per liter were found at depths of 59 and 64 feet. The contaminant was dispersed across a verti- cal interval of about 75 feet at depths of 19 and 94 feet. All of the TCE in ground water discharges to the Rock River because no TCE was detected below a depth of 109 feet, and increasing vertical head gradients with depth indicate ground-water flow from a depth of 119 feet is to the river. The maximum possible discharge of TCE is estimated to be about 1.7 grams per day. A finite-difference numerical model was used to simulate ground-water flow along a vertical section through the ground-water system from the Byron Superfund site to the Rock River. Results of the ground-water flow simulation indicate that, if underflow in the St. Peter aquifer occurs beneath the Rock River, it would be water that was present at depth in the flow system at the Byron Superfund site rather than contaminated water that had recharged the system in the vicinity of the Byron Superfund site. (USGS)

  19. Ground-Water Resources in Kaloko-Honokohau National Historical Park, Island of Hawaii, and Numerical Simulation of the Effects of Ground-Water Withdrawals

    Science.gov (United States)

    Oki, Delwyn S.; Tribble, Gordon W.; Souza, William R.; Bolke, Edward L.

    1999-01-01

    Within the Kaloko-Honokohau National Historical Park, which was established in 1978, the ground-water flow system is composed of brackish water overlying saltwater. Ground-water levels measured in the Park range from about 1 to 2 feet above mean sea level, and fluctuate daily by about 0.5 to 1.5 feet in response to ocean tides. The brackish water is formed by mixing of seaward flowing fresh ground water with underlying saltwater from the ocean. The major source of fresh ground water is from subsurface flow originating from inland areas to the east of the Park. Ground-water recharge from the direct infiltration of precipitation within the Park area, which has land-surface altitudes less than 100 feet, is small because of low rainfall and high rates of evaporation. Brackish water flowing through the Park ultimately discharges to the fishponds in the Park or to the ocean. The ground water, fishponds, and anchialine ponds in the Park are hydrologically connected; thus, the water levels in the ponds mark the local position of the water table. Within the Park, ground water near the water table is brackish; measured chloride concentrations of water samples from three exploratory wells in the Park range from 2,610 to 5,910 milligrams per liter. Chromium and copper were detected in water samples from the three wells in the Park and one well upgradient of the Park at concentrations of 1 to 5 micrograms per liter. One semi-volatile organic compound, phenol, was detected in water samples from the three wells in the Park at concentrations between 4 and 10 micrograms per liter. A regional, two-dimensional (areal), freshwater-saltwater, sharp-interface ground-water flow model was used to simulate the effects of regional withdrawals on ground-water flow within the Park. For average 1978 withdrawal rates, the estimated rate of fresh ground-water discharge to the ocean within the Park is about 6.48 million gallons per day, or about 3 million gallons per day per mile of coastline

  20. Ground Water Redox Zonation near La Pine, Oregon: Relation to River Position within the Aquifer-Riparian Zone Continuum

    Science.gov (United States)

    Hinkle, Stephen R.; Morgan, David S.; Orzol, Leonard L.; Polette, Danial J.

    2007-01-01

    Increasing residential development since in the 1960s has lead to increases in nitrate concentrations in shallow ground water in parts of the 247 square mile study area near La Pine, Oregon. Denitrification is the dominant nitrate-removal process that occurs in suboxic ground water, and suboxic ground water serves as a barrier to transport of most nitrate in the aquifer. Oxic ground water, on the other hand, represents a potential pathway for nitrate transport from terrestrial recharge areas to the Deschutes and Little Deschutes Rivers. The effects of present and potential future discharge of ground-water nitrate into the nitrogen-limited Deschutes and Little Deschutes Rivers are not known. However, additions of nitrogen to nitrogen-limited rivers can lead to increases in primary productivity which, in turn, can increase the magnitudes of dissolved oxygen and pH swings in river water. An understanding of the distribution of oxic ground water in the near-river environment could facilitate understanding the vulnerability of these rivers and could be a useful tool for management of these rivers. In this study, transects of temporary wells were installed in sub-river sediments beneath the Deschutes and Little Deschutes Rivers near La Pine to characterize near-river reduction/oxidation (redox) conditions near the ends of ground-water flow paths. Samples from transects installed near the center of the riparian zone or flood plain were consistently suboxic. Where transects were near edges of riparian zones, most ground-water samples also were suboxic. Oxic ground water (other than hyporheic water) was uncommon, and was only detected near the outside edge of some meander bends. This pattern of occurrence likely reflects geochemical controls throughout the aquifer as well as geochemical processes in the microbiologically active riparian zone near the end of ground-water flow paths. Younger, typically less reduced ground water generally enters near-river environments through

  1. Ground Water Redox Zonation near La Pine, Oregon: Relation to River Position within the Aquifer-Riparian Zone Continuum

    Science.gov (United States)

    Hinkle, Stephen R.; Morgan, David S.; Orzol, Leonard L.; Polette, Danial J.

    2007-01-01

    Increasing residential development since in the 1960s has lead to increases in nitrate concentrations in shallow ground water in parts of the 247 square mile study area near La Pine, Oregon. Denitrification is the dominant nitrate-removal process that occurs in suboxic ground water, and suboxic ground water serves as a barrier to transport of most nitrate in the aquifer. Oxic ground water, on the other hand, represents a potential pathway for nitrate transport from terrestrial recharge areas to the Deschutes and Little Deschutes Rivers. The effects of present and potential future discharge of ground-water nitrate into the nitrogen-limited Deschutes and Little Deschutes Rivers are not known. However, additions of nitrogen to nitrogen-limited rivers can lead to increases in primary productivity which, in turn, can increase the magnitudes of dissolved oxygen and pH swings in river water. An understanding of the distribution of oxic ground water in the near-river environment could facilitate understanding the vulnerability of these rivers and could be a useful tool for management of these rivers. In this study, transects of temporary wells were installed in sub-river sediments beneath the Deschutes and Little Deschutes Rivers near La Pine to characterize near-river reduction/oxidation (redox) conditions near the ends of ground-water flow paths. Samples from transects installed near the center of the riparian zone or flood plain were consistently suboxic. Where transects were near edges of riparian zones, most ground-water samples also were suboxic. Oxic ground water (other than hyporheic water) was uncommon, and was only detected near the outside edge of some meander bends. This pattern of occurrence likely reflects geochemical controls throughout the aquifer as well as geochemical processes in the microbiologically active riparian zone near the end of ground-water flow paths. Younger, typically less reduced ground water generally enters near-river environments through

  2. Delineating ground water recharge from leaking irrigation canals using water chemistry and isotopes.

    Science.gov (United States)

    Harvey, F E; Sibray, S S

    2001-01-01

    Across the Great Plains irrigation canals are used to transport water to cropland. Many of these canals are unlined, and leakage from them has been the focus of an ongoing legal, economic, and philosophical debate as to whether this lost water should be considered waste or be viewed as a beneficial and reasonable use since it contributes to regional ground water recharge. While historically there has been much speculation about the impact of canal leakage on local ground water, actual data are scarce. This study was launched to investigate the impact of leakage from the Interstate Canal, in the western panhandle of Nebraska, on the hydrology and water quality of the local aquifer using water chemistry and environmental isotopes. Numerous monitoring wells were installed in and around a small wetland area adjacent to the canal, and ground water levels were monitored from June 1992 until January 1995. Using the water level data, the seepage loss from the canal was estimated. In addition, the canal, the monitoring wells, and several nearby stock and irrigation wells were sampled for inorganic and environmental isotope analysis to assess water quality changes, and to determine the extent of recharge resulting from canal leakage. The results of water level monitoring within study wells indicates a rise in local ground water levels occurs seasonally as a result of leakage during periods when the canal is filled. This rise redirects local ground water flow and provides water to nearby wetland ecosystems during the summer months. Chemical and isotopic results were used to delineate canal, surface, and ground water and indicate that leaking canal water recharges both the surface alluvial aquifer and upper portions of the underlying Brule Aquifer. The results of this study indicate that lining the Interstate Canal could lower ground water levels adjacent to the canal, and could adversely impact the local aquifer.

  3. CHEMICAL QUALITY CHARACTERISTICS OF TEHRAN GROUND WATER

    Directory of Open Access Journals (Sweden)

    K. Imandel

    1994-06-01

    Full Text Available For better understanding of Tehran ground water, samples were taken randomly from 340 out of 655 deep & semi deep wells in 1993, which dug by Tehran Water Supply and Sewage Engineering Company. 260 Water specimens were examined chemically and physically and compared with the 1993 World Health Organization (WHO and Food and Agriculture Organization (FAO criteria and analyzed statistically. Logarithmic diagram of arithmetic mean of 53 deep wells which are now connected to Tehran water supply system showed Sodium- Sulphate category. Main chemical components of water are closely adjusted to the international standards and no overdoses were observed in any cases. Logarithmic diagram of arithmetic mean of 72 deep wells, which were rsed for the Tehran’s orbital town's drinking water, showed that chemical components of the water were Calcic-Chloride category and there were not observed any increases within the other compounds.

  4. Animating ground water levels with Excel.

    Science.gov (United States)

    Shikaze, Steven G; Crowe, Allan S

    2003-01-01

    This note describes the use of Microsoft Excel macros (programs written in Excel's internal language, Visual Basic for Applications) to create simple onscreen animations of transient ground water data within Excel. Compared to many specialized visualization software packages, the use of Excel macros is much cheaper, much simpler, and can rapidly be learned. The Excel macro can also be used to create individual GIF files for each animation frame. This series of frames can then be used to create an AVI video file using any of a number of graphics packages, such as Corel PhotoPaint. The technique is demonstrated through a macro that animates changes in the elevation of a water table along a transect over several years.

  5. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Naturita, Colorado. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project, and the Ground Water Project. For the UMTRA Project site located near Naturita, Colorado, phase I involves the removal of radioactively contaminated soils and materials and their transportation to a disposal site at Union Carbide Corporation`s Upper Burbank Repository at Uravan, Colorado. The surface cleanup will reduce radon and other radiation emissions from the former uranium processing site and prevent further site-related contamination of ground water. Phase II of the project will evaluate the nature and extent of ground water contamination resulting from uranium processing and its effect on human health and the environment, and will determine site-specific ground water compliance strategies in accordance with the US Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. Human health risks could occur from drinking water pumped from a hypothetical well drilled in the contaminated ground water area. Environmental risks may result if plants or animals are exposed to contaminated ground water or surface water that has mixed with contaminated ground water. Therefore, a risk assessment was conducted for the Naturita site. This risk assessment report is the first site-specific document prepared for the Ground Water Project at the Naturita site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine whether any action is needed to protect human health or the environment.

  6. Application of environmental tracers to mixing, evolution, and nitrate contamination of ground water in Jeju Island, Korea

    Science.gov (United States)

    Koh, D.-C.; Niel, Plummer L.; Kip, Solomon D.; Busenberg, E.; Kim, Y.-J.; Chang, H.-W.

    2006-01-01

    Tritium/helium-3 (3H/3He) and chlorofluorocarbons (CFCs) were investigated as environmental tracers in ground water from Jeju Island (Republic of Korea), a basaltic volcanic island. Ground-water mixing was evaluated by comparing 3H and CFC-12 concentrations with lumped-parameter dispersion models, which distinguished old water recharged before the 1950s with negligible 3H and CFC-12 from younger water. Low 3H levels in a considerable number of samples cannot be explained by the mixing models, and were interpreted as binary mixing of old and younger water; a process also identified in alkalinity and pH of ground water. The ground-water CFC-12 age is much older in water from wells completed in confined zones of the hydro-volcanic Seogwipo Formation in coastal areas than in water from the basaltic aquifer. Major cation concentrations are much higher in young water with high nitrate than those in uncontaminated old water. Chemical evolution of ground water resulting from silicate weathering in basaltic rocks reaches the zeolite-smectite phase boundary. The calcite saturation state of ground water increases with the CFC-12 apparent (piston flow) age. In agricultural areas, the temporal trend of nitrate concentration in ground water is consistent with the known history of chemical fertilizer use on the island, but increase of nitrate concentration in ground water is more abrupt after the late 1970s compared with the exponential growth of nitrogen inputs. ?? 2005 Elsevier B.V. All rights reserved.

  7. Ground-Water Temperature, Noble Gas, and Carbon Isotope Data from the Espanola Basin, New Mexico

    Science.gov (United States)

    Manning, Andrew H.

    2009-01-01

    Ground-water samples were collected from 56 locations throughout the Espanola Basin and analyzed for general chemistry (major ions and trace elements), carbon isotopes (delta 13C and 14C activity) in dissolved inorganic carbon, noble gases (He, Ne, Ar, Kr, Xe, and 3He/4He ratio), and tritium. Temperature profiles were measured at six locations in the southeastern part of the basin. Temperature profiles suggest that ground water generally becomes warmer with distance from the mountains and that most ground-water flow occurs at depths 50 years old, consistent with the 14C ages. Terrigenic He (Heterr) concentrations in ground water are high (log Delta Heterr of 2 to 5) throughout much of the basin. High Heterr concentrations are probably caused by in situ production in the Tesuque Formation from locally high concentrations of U-bearing minerals (Northeast zone only), or by upward diffusive/advective transport of crustal- and mantle-sourced He possibly enhanced by basement piercing faults, or by both. The 3He/4He ratio of Heterr (Rterr) is commonly high (Rterr/Ra of 0.3-2.0, where Ra is the 3He/4He ratio in air) suggesting that Espanola Basin ground water commonly contains mantle-sourced He. The 3He/4He ratio of Heterr is generally the highest in the western and southern parts of the basin, closest to the western border fault system and the Quaternary to Miocene volcanics of the Jemez Mountains and Cerros del Rio.

  8. Factors affecting ground-water exchange and catchment size for Florida lakes in mantled karst terrain

    Science.gov (United States)

    Lee, Terrie Mackin

    2002-01-01

    In the mantled karst terrain of Florida, the size of the catchment delivering ground-water inflow to lakes is often considerably smaller than the topographically defined drainage basin. The size is determined by a balance of factors that act individually to enhance or diminish the hydraulic connection between the lake and the adjacent surficial aquifer, as well as the hydraulic connection between the surficial aquifer and the deeper limestone aquifer. Factors affecting ground-water exchange and the size of the ground-water catchment for lakes in mantled karst terrain were examined by: (1) reviewing the physical and hydrogeological characteristics of 14 Florida lake basins with available ground-water inflow estimates, and (2) simulating ground-water flow in hypothetical lake basins. Variably-saturated flow modeling was used to simulate a range of physical and hydrogeologic factors observed at the 14 lake basins. These factors included: recharge rate to the surficial aquifer, thickness of the unsaturated zone, size of the topographically defined basin, depth of the lake, thickness of the surficial aquifer, hydraulic conductivity of the geologic units, the location and size of karst subsidence features beneath and onshore of the lake, and the head in the Upper Floridan aquifer. Catchment size and the magnitude of ground-water inflow increased with increases in recharge rate to the surficial aquifer, the size of the topographically defined basin, hydraulic conductivity in the surficial aquifer, the degree of confinement of the deeper Upper Floridan aquifer, and the head in the Upper Floridan aquifer. The catchment size and magnitude of ground-water inflow increased with decreases in the number and size of karst subsidence features in the basin, and the thickness of the unsaturated zone near the lake. Model results, although qualitative, provided insights into: (1) the types of lake basins in mantled karst terrain that have the potential to generate small and large

  9. Groupage Cargo Transportation Model

    Directory of Open Access Journals (Sweden)

    Aleksejevs Ruslans

    2016-03-01

    Full Text Available In this work we consider a specific problem of optimal planning of maritime transportation of multiproduct cargo by ships of one (corporate strategy or several (partially corporate strategy companies: the core of the problem consists of the existence of the network of intermediate seaports (i.e. transitional seaports, where for every ship arrived the cargo handling is done, and which are situated between the starting and the finishing seaports. In this work, there are mathematical models built from scratch in the form of multicriteria optimization problem; then the goal attainment method of Gembicki is used for reducing the built models to a one-criterion problem of linear programming.

  10. Tomography of ground water flow from self-potential data

    Science.gov (United States)

    Revil, A.; Jardani, A.

    2007-12-01

    An inversion algorithm is developed to interpret self-potential (SP) data in terms of distribution of the seepage velocity of the ground water. The model is based on the proportionality existing between the electrokinetic source current density and the seepage velocity of the water phase. As the inverse problem is underdetermined, we use a Tikhonov regularization method with a smoothness constraint based on the differential Laplacian operator to solve the inverse problem. The regularization parameter is determined by the L-shape method. The recovery of the distribution of the seepage velocity vector of the ground water flow depends on the localization and number of non-polarizing electrodes and information relative to the distribution of the electrical resistivity of the ground. The inversion method is tested on two 2D synthetic cases and on two real SP data. The first field test corresponds to the infiltration of water from a ditch. The second one corresponds to large flow at the Cerro Prieto geothermal field in Baja California.

  11. Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface ground water: background, base cases, shallow reservoirs, short-term gas and water transport

    Science.gov (United States)

    Researchers examined gas and water transport between a deep tight shale gas reservoir and a shallow overlying aquifer in the two years following hydraulic fracturing, assuming a pre-existing connecting pathway.

  12. Ground-water resources of Cambodia

    Science.gov (United States)

    Rasmussen, William Charles; Bradford, Gary M.

    1977-01-01

    available information is on the central lowlands and contiguous low plateaus, as the mountainous areas on the west and the high plateaus on the east are relatively unexplored with respect to their ground-water availability. No persistent artesian aquifer has been identified nor have any large potential ground-water sources been found .although much of the country yet remains to be explored by test drilling. Well irrigation for garden produce is feasible on a modest scale in many localities throughout Cambodia. It does not seem likely, however, that large-scale irrigation from wells will come about in the future. Ground water may be regarded as a widely available supplemental source to surface water for domestic, small-scale industrial, and irrigation use.

  13. Ground-water system, estimation of aquifer hydraulic properties, and effects of pumping on ground-water flow in Triassic sedimentary rocks in and near Lansdale, Pennsylvania

    Science.gov (United States)

    Senior, Lisa A.; Goode, Daniel J.

    1999-01-01

    Ground water in Triassic-age sedimentary fractured-rock aquifers in the area of Lansdale, Pa., is used as drinking water and for industrial supply. In 1979, ground water in the Lansdale area was found to be contaminated with trichloroethylene, tetrachloroethylene, and other man-made organic compounds, and in 1989, the area was placed on the U.S. Environmental Protection Agency's (USEPA) National Priority List as the North Penn Area 6 site. To assist the USEPA in the hydrogeological assessment of the site, the U.S. Geological Survey began a study in 1995 to describe the ground-water system and to determine the effects of changes in the well pumping patterns on the direction of ground-water flow in the Lansdale area. This determination is based on hydrologic and geophysical data collected from 1995-98 and on results of the simulation of the regional ground-water-flow system by use of a numerical model.Correlation of natural-gamma logs indicate that the sedimentary rock beds strike generally northeast and dip at angles less than 30 degrees to the northwest. The ground-water system is confined or semi-confined, even at shallow depths; depth to bedrock commonly is less than 20 feet (6 meters); and depth to water commonly is about 15 to 60 feet (5 to 18 meters) below land surface. Single-well, aquifer-interval-isolation (packer) tests indicate that vertical permeability of the sedimentary rocks is low. Multiple-well aquifer tests indicate that the system is heterogeneous and that flow appears primarily in discrete zones parallel to bedding. Preferred horizontal flow along strike was not observed in the aquifer tests for wells open to the pumped interval. Water levels in wells that are open to the pumped interval, as projected along the dipping stratigraphy, are drawn down more than water levels in wells that do not intersect the pumped interval. A regional potentiometric map based on measured water levels indicates that ground water flows from Lansdale towards discharge

  14. Transport hub flow modelling

    OpenAIRE

    Despagne, Wilfried; Frenod, Emmanuel

    2014-01-01

    Purpose: The purpose of this paper is to investigate the road freight haulage activity. Using the physical and data flow information from a freight forwarder, we intend to model the flow of inbound and outbound goods in a freight transport hub. Approach: This paper presents the operation of a road haulage group. To deliver goods within two days to any location in France, a haulage contractor needs to be part of a network. This network handles the processing of both physical goods and data. We...

  15. Summary of the Ground-Water-Level Hydrologic Conditions in New Jersey 2006

    Science.gov (United States)

    Jones, Walter; Pope, Daryll

    2007-01-01

    Ground water is one of the Nation's most important natural resources. It provides about 40 percent of our Nation's public water supply. Currently, nearly one-half of New Jersey's drinking-water is supplied by over 300,000 wells that serve more than 4.3 million people (John P. Nawyn, U.S. Geological Survey, written commun., 2007). New Jersey's population is projected to grow by more than a million people by 2030 (U.S. Census Bureau, accessed March 2, 2006, at http://www.census.gov). As demand for water increases, managing the development and use of the ground-water resource so that the supply can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences is of paramount importance. This report describes the U.S. Geological Survey (USGS) New Jersey Water Science Center Observation Well Networks. Record low ground-water levels during water year 2006 (October 1, 2005 to September 30, 2006) are listed, and water levels in six selected water-table observation wells and three selected confined wells are shown in hydrographs. The report describes the trends in water levels in various confined aquifers in southern New Jersey and in water-table and fracture rock aquifers throughout the State. Web site addresses to access the data also are included. The USGS has operated a network of observation wells in New Jersey since 1923 for the purpose of monitoring ground-water-level changes throughout the State. Long-term systematic measurement of water levels in observation wells provides the data needed to evaluate changes in the ground-water resource over time. Records of ground-water levels are used to evaluate the effects of climate changes and water-supply development, to develop ground-water models, and to forecast trends.

  16. Thermal Methods for Investigating Ground-Water Recharge

    Science.gov (United States)

    Blasch, Kyle W.; Constantz, Jim; Stonestrom, David A.

    2007-01-01

    Recharge of aquifers within arid and semiarid environments is defined as the downward flux of water across the regional water table. The introduction of recharging water at the land surface can occur at discreet locations, such as in stream channels, or be distributed over the landscape, such as across broad interarroyo areas within an alluvial ground-water basin. The occurrence of recharge at discreet locations is referred to as focused recharge, whereas the occurrence of recharge over broad regions is referred to as diffuse recharge. The primary interest of this appendix is focused recharge, but regardless of the type of recharge, estimation of downward fluxes is essential to its quantification. Like chemical tracers, heat can come from natural sources or be intentionally introduced to infer transport properties and aquifer recharge. The admission and redistribution of heat from natural processes such as insolation, infiltration, and geothermal activity can be used to quantify subsurface flow regimes. Heat is well suited as a ground-water tracer because it provides a naturally present dynamic signal and is relatively harmless over a useful range of induced perturbations. Thermal methods have proven valuable for recharge investigations for several reasons. First, theoretical descriptions of coupled water-and-heat transport are available for the hydrologic processes most often encountered in practice. These include land-surface mechanisms such as radiant heating from the sun, radiant cooling into space, and evapotranspiration, in addition to the advective and conductive mechanisms that usually dominate at depth. Second, temperature is theoretically well defined and readily measured. Third, thermal methods for depths ranging from the land surface to depths of hundreds of meters are based on similar physical principles. Fourth, numerical codes for simulating heat and water transport have become increasingly reliable and widely available. Direct measurement of water

  17. Factors Affecting Nitrate Delivery to Streams from Shallow Ground Water in the North Carolina Coastal Plain

    Science.gov (United States)

    Harden, Stephen L.; Spruill, Timothy B.

    2008-01-01

    An analysis of data collected at five flow-path study sites between 1997 and 2006 was performed to identify the factors needed to formulate a comprehensive program, with a focus on nitrogen, for protecting ground water and surface water in the North Carolina Coastal Plain. Water-quality protection in the Coastal Plain requires the identification of factors that affect the transport of nutrients from recharge areas to streams through the shallow ground-water system. Some basins process or retain nitrogen more readily than others, and the factors that affect nitrogen processing and retention were the focus of this investigation to improve nutrient management in Coastal Plain streams and to reduce nutrient loads to coastal waters. Nitrate reduction in ground water was observed at all five flow-path study sites in the North Carolina Coastal Plain, although the extent of reduction at each site was influenced by various environmental, hydrogeologic, and geochemical factors. Denitrification was the most common factor responsible for decreases in nitrate along the ground-water flow paths. Specific factors, some of which affect denitrification rates, that appeared to influence ground-water nitrate concentrations along the flow paths or in the streams include soil drainage, presence or absence of riparian buffers, evapotranspiration, fertilizer use, ground-water recharge rates and residence times, aquifer properties, subsurface tile drainage, sources and amounts of organic matter, and hyporheic processes. The study data indicate that the nitrate-reducing capacity of the buffer zone combined with that of the hyporheic zone can substantially lower the amount of ground-water nitrate discharged to streams in agricultural settings of the North Carolina Coastal Plain. At the watershed scale, the effects of ground-water discharge on surface-water quality appear to be greatly influenced by streamflow conditions and the presence of extensive riparian vegetation. Streamflow statistics

  18. 40 CFR 257.3-4 - Ground water.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground water. 257.3-4 Section 257.3-4... and Practices § 257.3-4 Ground water. (a) A facility or practice shall not contaminate an underground drinking water source beyond the solid waste boundary or beyond an alternative boundary specified...

  19. Ground-water conditions in Whisky Flat, Mineral County, Nevada

    Science.gov (United States)

    Eakin, T.E.; Robinson, T.W.

    1950-01-01

    As a part of the State-wide cooperative program between the Office of the State Engineer of Nevada and the U.S. Geological Survey, the Ground Water Branch of the Geological Survey made a reconnaissance study of ground-water conditions in Whisky Flat, Mineral County, Nevada.

  20. Contamination of Ground Water Samples from Well Installations

    DEFF Research Database (Denmark)

    Grøn, Christian; Madsen, Jørgen Øgaard; Simonsen, Y.

    1996-01-01

    Leaching of a plasticizer, N-butylbenzenesulfonamide, from ground water multilevel sampling installations in nylon has been demonstrated. The leaching resulted in concentrations of DOC and apparent AOX, both comparable with those observed in landfill contaminated ground waters. It is concluded th...

  1. IN-SITU BIOREMEDIATION OF CONTAMINATED GROUND WATER

    Science.gov (United States)

    This document is one in a series of Ground Water Issue papers which have been prepared in response to needs expressed by the Ground Water Forum. It is based on findings from the research community in concert with experience gained at sites undergoing remediation. the intent of th...

  2. Ground water hydrology report: Revision 1, Attachment 3. Final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    This report presents ground water hydrogeologic activities for the Maybell, Colorado, Uranium Mill Tailings Remedial Action Project site. The Department of Energy has characterized the hydrogeology, water quality, and water resources at the site and determined that the proposed remedial action would comply with the requirements of the EPA ground water protection standards.

  3. Procedures for ground-water investigations. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water monitoring procedures are developed and used in accordance with the PNL Quality Assurance Program.

  4. Ground-water flow and the possible effects of remedial actions at J-Field, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Hughes, W.B.

    1995-01-01

    J-Field, located in the Edgewood Area of Aberdeen Proving Ground, Md, has been used since World War II to test and dispose of explosives, chemical warfare agents, and industrial chemicals resulting in ground-water, surface-water, and soil contami- nation. The U.S. Geological Survey finite-difference model was used to better understand ground-water flow at the site and to simulate the effects of remedial actions. A surficial aquifer and a confined aquifer were simulated with the model. A confining unit separates these units and is represented by leakance between the layers. The area modeled is 3.65 mi2; the model was constructed with a variably spaced 40 X 38 grid. The horizontal and lower boundaries of the model are all no-flow boundaries. Steady-state conditions were used. Ground water at the areas under investigation flows from disposal pit areas toward discharge areas in adjacent estuaries or wetlands. Simulations indicate that capping disposal areas with an impermeable cover effectively slows advective ground water flow by 0.7 to 0.5 times. Barriers to lateral ground-water flow were simulated and effectively prevented the movement of ground water toward discharge areas. Extraction wells were simulated as a way to contain ground-water contamination and to extract ground water for treatment. Two wells pumping 5 gallons per minute each at the toxic-materials disposal area and a single well pumping 2.5 gallons per minute at the riot-control-agent disposal area effectively contained contamination at these sites. A combi- nation of barriers to horizontal flow east and south of the toxic-materials disposal area, and a single extraction well pumping at 5 gallons per minute can extract contaminated ground water and prevent pumpage of marsh water.

  5. Ground-water flow related to streamflow and water quality

    Science.gov (United States)

    Van Voast, W. A.; Novitzki, R.P.

    1968-01-01

    A ground-water flow system in southwestern Minnesota illustrates water movement between geologic units and between the land surface and the subsurface. The flow patterns indicate numerous zones of ground-water recharge and discharge controlled by topography, varying thicknesses of geologic units, variation in permeabilities, and the configuration of the basement rock surface. Variations in streamflow along a reach of the Yellow Medicine River agree with the subsurface flow system. Increases and decreases in runoff per square mile correspond, apparently, to ground-water discharge and recharge zones. Ground-water quality variations between calcium sulfate waters typical of the Quaternary drift and sodium chloride waters typical of the Cretaceous rocks are caused by mixing of the two water types. The zones of mixing are in agreement with ground-water flow patterns along the hydrologic section.

  6. Nitrate retention in riparian ground water at natural and elevated nitrate levels in North Central Minnesota

    Science.gov (United States)

    Duff, J.H.; Jackman, A.P.; Triska, F.J.; Sheibley, R.W.; Avanzino, R.J.

    2007-01-01

    The relationship between local ground water flows and NO3- transport to the channel was examined in three well transects from a natural, wooded riparian zone adjacent to the Shingobee River, MN. The hillslope ground water originated as recharge from intermittently grazed pasture up slope of the site. In the hillslope transect perpendicular to the stream, ground water NO3- concentrations decreased from ???3 mg N L-1 beneath the ridge (80 m from the channel) to 0.01 to 1.0 mg N L-1 at wells 1 to 3 m from the channel. The Cl- concentrations and NO3/Cl ratios decreased toward the channel indicating NO3- dilution and biotic retention. In the bankside well transect parallel to the stream, two distinct ground water environments were observed: an alluvial environment upstream of a relict beaver dam influenced by stream water and a hillslope environment downstream of the relict beaver dam. Nitrate was elevated to levels representative of agricultural runoff in a third well transect looted ???5 m from the stream to assess the effectiveness of the riparian zone as a NO3- sink. Subsurface NO3- injections revealed transport of up to 15 mg N L-1 was nearly conservative in the alluvial riparian environment. Addition of glucose stimulated dissolved oxygen uptake and promoted NO3- retention under both background and elevated NO 3- levels in summer and winter. Disappearance of added NO3- was followed by transient NO2- formation and, in the presence of C2H2, by N2O formation, demonstrating potential denitrification. Under current land use, most NO3- associated with local ground water is biotically retained or diluted before reaching the channel. However, elevating NO 3- levels through agricultural cultivation would likely result in increased NO3- transport to the channel. ?? ASA, CSSA, SSSA.

  7. Application of GIS and MODFLOW to Ground Water Hydrology- A Review

    Directory of Open Access Journals (Sweden)

    Singha Sudhakar

    2016-01-01

    Full Text Available Groundwater is one of the most valuable natural resources, which supports human health, economic development and ecological diversity. Due to over exploitation, the ground water systems are affected and require management to maintain the conditions of ground water resources within acceptable limits. With the development of computers and advances in information technology, efficient techniques for water management has evolved. The main intent of the paper is to present a comprehensive review on application of GIS (Geographic Information System followed by coupling with MODFLOW package for ground water management and development. Two major areas are discussed stating GIS applications in ground water hydrology. (i GIS based subsurface flow and pollution modelling (ii Selection of artificial recharge sites. Although the use of these techniques in groundwater studies has rapidly increased since last decade the sucess rate is very limited. Based on this review , it is concluded that integation of GIS and MODFLOW have great potential to revolutionize the monitoring and management of vital ground water resources in the future.

  8. The anti-obesity effect of natural vanadium-containing Jeju ground water.

    Science.gov (United States)

    Park, Seon-Joo; Youn, Cha-Kyung; Hyun, Jin Won; You, Ho Jin

    2013-02-01

    This study investigated the anti-obesity effects of Jeju ground water containing the vanadium components S1 (8.0 ± 0.9 μg/l) and S3 (26.0 ± 2.09 μg/l) on the differentiation of 3 T3-L1 preadipocytes and obesity in mice that were fed a high-fat diet (HFD). The 3 T3-L1 preadipocyte cells were cultured and differentiated in media consisting of Jeju ground water (S1, S3) or deionized water (DW) containing dexamethasone, isobutylmethylxanthine, and insulin. Oil Red O staining showed that lipid accumulation was attenuated in adipocyte cells treated with Jeju ground water. S3 significantly decreased peroxisome-activated receptor γ and CCAAT-enhancer-binding protein α mRNA expression levels, which play major roles in the transcriptional control of adipogenesis, compared to DW. Furthermore, mRNA expression levels of targeted genes, such as adipocyte fatty acid, lipoprotein lipase, and leptin, were decreased by S3 treatment compared with the control group. In mice with HFD-induced obesity, Jeju ground water decreased HFD-induced body weight gain and reduced total cholesterol, triglyceride, and glucose levels in the plasma compared to control mice. Taken together, Jeju ground water inhibits preadipocyte differentiation and adipogenesis in obesity animal models.

  9. Hydrochemistry of the Mahomet Bedrock Valley Aquifer, East-Central Illinois: indicators of recharge and ground-water flow

    Science.gov (United States)

    Panno, S.V.; Hackley, Keith C.; Cartwright, K.; Liu, Chao-Li

    1994-01-01

    A conceptual model of the ground-water flow and recharge to the Mahomet Bedrock Valley Aquifer (MVA), east-central Illinois, was developed using major ion chemistry and isotope geochemistry. The MVA is a 'basal' fill in the east-west trending buried bedrock valley composed of clean, permeable sand and gravel to thicknesses of up to 61 m. It is covered by a thick sequence of glacial till containing thinner bodies of interbedded sand and gravel. Ground water from the MVA was found to be characterized by clearly defined geochemical regions with three distinct ground-water types. A fourth ground-water type was found at the confluence of the MVA and the Mackinaw Bedrock Valley Aquifer (MAK) to the west. Ground water in the Onarga Valley, a northeastern tributary of the MVA, is of two types, a mixed cation-SO42- type and a mixed cation-HCO3- type. The ground water is enriched in Na+, Ca2+, Mg2+, and SO42- which appears to be the result of an upward hydraulic gradient and interaction of deeper ground water with oxidized pyritic coals and shale. We suggest that recharge to the Onarga Valley and overlying aquifers is 100% from bedrock (leakage) and lateral flow from the MVA to the south. The central MVA (south of the Onarga Valley) is composed of relatively dilute ground water of a mixed cation-HCO3- type, with low total dissolved solids, and very low concentrations of Cl- and SO42-. Stratigraphic relationships of overlying aquifers and ground-water chemistry of these and the MVA suggest recharge to this region of the MVA (predominantly in Champaign County) is relatively rapid and primarily from the surface. Midway along the westerly flow path of the MVA (western MVA), ground water is a mixed cation-HCO3- type with relatively high Cl-, where Cl- increases abruptly by one to ??? two orders of magnitude. Data suggest that the increase in Cl- is the result of leakage of saline ground water from bedrock into the MVA. Mass-balance calculations indicate that approximately 9.5% of

  10. Hydrogeology and simulation of ground-water flow, Picatinny Arsenal and vicinity, Morris County, New Jersey

    Science.gov (United States)

    Voronin, L.M.; Rice, D.E.

    1996-01-01

    Ground-water flow in glacial sediments and bedrock at Picatinny Arsenal, N.J., was simulated by use of a three-dimensional finite-difference ground- water-flow model. The modeled area includes a 4.3-square-mile area that extends from Picatinny Lake to the Rockaway River. Most of the study area is bounded by the natural hydrologic boundaries of the ground-water system. eophysical logs, lithologic logs, particle-size data, and core data from selected wells and surface geophysical data were analyzed to define the hydrogeologic framework. Hydrogeologic sections and thickness maps define six permeable and three low-permeability layers that are represented in the model as aquifers and confining units, respectively. Hydrologic data incorporated in the model include a rate of recharge from precipitation of 22 inches per year, estimated from long-term precipitation records and estimates of evapotranspiration. Additional recharge from infiltration along valleys was estimated from measured discharge of springs along the adjacent valley walls and from estimates of runoff from upland drainage that flows to the valley floor. Horizontal and vertical hydraulic conductivities of permeable and low-permeability layers were estimated from examination of aquifer-test data, gamma-ray logs, borehole cuttings, and previously published data. Horizontal hydraulic conductivities in glacial sediments range from 10 to 380 feet per day. Vertical hydraulic conductivities of the low-permeability layers range from 0.01 to 0.7 feet per day. The model was calibrated by simulating steady-state conditions during 1989-93 and by closely matching simulated and measured ground-water levels, vertical ground-water-head differences, and streamflow gain and loss. Simulated steady-state potentiometric- surface maps produced for the six permeable layers indicate that ground water in the unconfined material within Picatinny Arsenal flows predominantly toward the center of the valley, where it discharges to Green

  11. EFFECT OF SANTA ROSA LAKE ON GROUND WATER FLOW TO THE PECOS RIVER, NEW MEXICO.

    Science.gov (United States)

    Risser, Dennis W.

    1985-01-01

    In 1980, Santa Rosa Dam began impounding water on the Pecos River about 7 miles (11 kilometers) north of Santa Rosa, New Mexico, to provide flood control and storage for irrigation. Santa Rosa Lake has caused changes in the ground water flow system, which may cause changes in the streamflow of the Pecos River that cannot be detected at the present streamflow-gaging stations, which are used to administer water rights along the Pecos River. The effect of the lake on streamflow was investigated using a three-dimensional ground water flow model. These simulations indicated that the net change in ground water flow to the river would be almost zero if the lake were maintained at its flood control pool for 90 days.

  12. Estimating ground water recharge from topography, hydrogeology, and land cover.

    Science.gov (United States)

    Cherkauer, Douglas S; Ansari, Sajjad A

    2005-01-01

    Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long-term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine-tuned with other methods as time permits. Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases. The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed-parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error < 12%.

  13. Ground-water contamination from lead shot at Prime Hook National Wildlife Refuge, Sussex County, Delaware

    Science.gov (United States)

    Soeder, Daniel J.; Miller, Cherie V.

    2003-01-01

    Prime Hook National Wildlife Refuge is located in southeastern Delaware in coastal lowlands along the margin of Delaware Bay. For 37 years, the Broadkiln Sportsman?s Club adjacent to the refuge operated a trap-shooting range, with the clay-target launchers oriented so that the expended lead shot from the range dropped into forested wetland areas on the refuge property. Investigators have estimated that up to 58,000 shotgun pellets per square foot are present in locations on the refuge where the lead shot fell to the ground. As part of the environmental risk assessment for the site, the U.S. Geological Survey (USGS) investigated the potential for lead contamination in ground water. Results from two sampling rounds in 19 shallow wells indicate that elevated levels of dissolved lead are present in ground water at the site. The lead and associated metals, such as antimony and arsenic (common shotgun pellet alloys), are being transported along shallow ground-water flowpaths toward an open-water slough in the forested wetland adjacent to the downrange target area. Water samples from wells located along the bank of the slough contained dissolved lead concentrations higher than 400 micrograms per liter, and as high as 1 milligram per liter. In contrast, a natural background concentration of lead from ground water in a well upgradient from the site is about 1 microgram per liter. Two water samples collected several months apart from the slough directly downgradient of the shooting range contained 24 and 212 micrograms per liter of lead, respectively. The data indicate that lead from a concentrated deposit of shotgun pellets on the refuge has been mobilized through a combination of acidic water conditions and a very sandy, shallow, unconfined aquifer, and is moving along ground-water flowpaths toward the surface-water drainage. Data from this study will be used to help delineate the lead plume, and determine the fate and transport of lead from the source area.

  14. Role of ground water in geomorphology, geology, and paleoclimate of the Southern High Plains, USA.

    Science.gov (United States)

    Wood, Warren W

    2002-01-01

    Study of ground water in the Southern High Plains is central to an understanding of the geomorphology, deposition of economic minerals, and climate change record in the area. Ground water has controlled the course of the Canadian and Pecos rivers that isolated the Southern High Plains from the Great Plains and has contributed significantly to the continuing retreat of the westward escarpment. Evaporative and dissolution processes are responsible for current plateau topography and the development of the signature 20,000 small playa basins and 40 to 50 large saline lake basins in the area. In conjunction with eolian processes, ground water transport controls the mineralogy of commercially valuable mineral deposits and sets up the distribution of fine efflorescent salts that adversely affect water quality. As the water table rises and retreats, lunette and tufa formation provides valuable paleoclimate data for the Southern High Plains. In all these cases, an understanding of ground water processes contributes valuable information to a broad range of geological topics, well beyond traditional interest in water supply and environmental issues.

  15. Environmental Effect / Impact Assessment of Industrial Effulent on Ground Water

    Directory of Open Access Journals (Sweden)

    Dr. Parmod Kumar

    2013-12-01

    Full Text Available In the present study the aim of investigation is physical and chemical parameters of ground water and soil. By selected Physical and chemical parameters it is found that (1.Biological oxygen demand (BOD and chemical oxygen demand (COD are directly proportional to each other where dissolved oxygen (DO is indirectly proportional to BOD and COD. (2. Total dissolved solids, alkalinity and hardness are significantly higher in pre monsoon and winter season as compared to monsoon season.(3. High values of different parameters of ground water sources indicate the influence of industrial wastes on ground water.

  16. Ground-water and precipitation data for South Carolina, 1990

    Science.gov (United States)

    Conrads, Paul A.; Jones, Kathy H.; Stringfield, Whitney J.

    1994-01-01

    Continuous water-level data collected from 53 wells in South Carolina during 1990 provide the basic data for this report. Hydrographs are presented for selected wells to illustrate the effects that changes in ground-water recharge and artificial ground-water discharge have had on the ground-water reservoirs in the State. Daily mean water levels are listed in tables. Monthly mean water levels for 1990 and for the entire period of record at each monitoring well are depicted in hydrographs. Also included are precipitation records from ten National Weather Service stations in South Carolina.

  17. Evaluation of geohydrologic framework, recharge estimates and ground-water flow of the Joshua Tree area, San Bernardino County, California

    Science.gov (United States)

    Nishikawa, Tracy; Izbicki, John A.; Hevesi, Joseph A.; Stamos, Christina L.; Martin, Peter

    2005-01-01

    Ground water historically has been the sole source of water supply for the community of Joshua Tree in the Joshua Tree ground-water subbasin of the Morongo ground-water basin in the southern Mojave Desert. The Joshua Basin Water District (JBWD) supplies water to the community from the underlying Joshua Tree ground-water subbasin. The JBWD is concerned with the long-term sustainability of the underlying aquifer. To help meet future demands, the JBWD plans to construct production wells in the adjacent Copper Mountain ground-water subbasin. As growth continues in the desert, there may be a need to import water to supplement the available ground-water resources. In order to manage the ground-water resources and to identify future mitigating measures, a thorough understanding of the ground-water system is needed. The purpose of this study was threefold: (1) improve the understanding of the geohydrologic framework of the Joshua Tree and Copper Mountain ground-water subbasins, (2) determine the distribution and quantity of recharge using field and numerical techniques, and (3) develop a ground-water flow model that can be used to help manage the water resources of the region. The geohydrologic framework was refined by collecting and interpreting water-level and water-quality data, geologic and electric logs, and gravity data. The water-bearing deposits in the Joshua Tree and Copper Mountain ground-water subbasins are Quarternary alluvial deposits and Tertiary sedimentary and volcanic deposits. The Quarternary alluvial deposits were divided into two aquifers (referred to as the 'upper' and the 'middle' alluvial aquifers), which are about 600 feet (ft) thick, and the Tertiary sedimentary and volcanic deposits were assigned to a single aquifer (referred to as the 'lower' aquifer), which is as thick as 1,500 ft. The ground-water quality of the Joshua Tree and Copper Mountain ground-water subbasins was defined by collecting 53 ground-water samples from 15 wells (10 in the

  18. Simulation of ground-water/surface-water flow in the Santa Clara-Calleguas ground-water basin, Ventura County, California

    Science.gov (United States)

    Hanson, Randall T.; Martin, Peter; Koczot, Kathryn M.

    2003-01-01

    Ground water is the main source of water in the Santa Clara-Calleguas ground-water basin that covers about 310 square miles in Ventura County, California. A steady increase in the demand for surface- and ground-water resources since the late 1800s has resulted in streamflow depletion and ground-water overdraft. This steady increase in water use has resulted in seawater intrusion, inter-aquifer flow, land subsidence, and ground-water contamination. The Santa Clara-Calleguas Basin consists of multiple aquifers that are grouped into upper- and lower-aquifer systems. The upper-aquifer system includes the Shallow, Oxnard, and Mugu aquifers. The lower-aquifer system includes the upper and lower Hueneme, Fox Canyon, and Grimes Canyon aquifers. The layered aquifer systems are each bounded below by regional unconformities that are overlain by extensive basal coarse-grained layers that are the major pathways for ground-water production from wells and related seawater intrusion. The aquifer systems are bounded below and along mountain fronts by consolidated bedrock that forms a relatively impermeable boundary to ground-water flow. Numerous faults act as additional exterior and interior boundaries to ground-water flow. The aquifer systems extend offshore where they crop out along the edge of the submarine shelf and within the coastal submarine canyons. Submarine canyons have dissected these regional aquifers, providing a hydraulic connection to the ocean through the submarine outcrops of the aquifer systems. Coastal landward flow (seawater intrusion) occurs within both the upper- and lower-aquifer systems. A numerical ground-water flow model of the Santa Clara-Calleguas Basin was developed by the U.S. Geological Survey to better define the geohydrologic framework of the regional ground-water flow system and to help analyze the major problems affecting water-resources management of a typical coastal aquifer system. Construction of the Santa Clara-Calleguas Basin model required

  19. EFFECT OF GROUND-WATER REMEDIATION ACTIVITIES ON INDIGENOUS MICROFLORA

    Science.gov (United States)

    The United States Environmental Protection Agency (EPA), working with the Interagency DNAPL Consortium, completed an independent evaluation of microbial responses to ground-water remediation technology demonstrations at Launch Pad 34 at Cape Canaveral Air Station in Brevard Count...

  20. Arsenic in Ground Water of the United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This image shows national-scale patterns of naturally occurring arsenic in potable ground-water resources of the continental United States. The image was generated...

  1. Ground-water monitoring sites for Carson Valley, Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains the monitoring sites where water levels were collected and used to develop a spatial ground-water data base in Carson Valley, west-central...

  2. Contamination of Ground Water Due To Landfill Leachate

    Directory of Open Access Journals (Sweden)

    M. V. S. Raju

    2012-12-01

    Full Text Available The present site under investigation at Ajitsingh Nagar in Vijayawada of Andhra Pradesh is initially a low lying area and used for disposing the urban solid waste for the last few years, through open dumping with out taking any measures to protect the Ground water against pollution. The present study has been taken up to measure the degree of pollution of ground water due to leachate produced in the landfill site. Bore holes were made at eight random locations to measure the depth and characteristics of solid waste. Four sampling wells were made for the collection of ground water samples and they were analyzed for various parameters. All parameters were measured based on Standard methods. It is found that the ground water is contaminated due leachates of Landfill to the large extent and is not suitable for Drinking, Domestic and Irrigation purposes.

  3. Stochastic models of intracellular transport

    KAUST Repository

    Bressloff, Paul C.

    2013-01-09

    The interior of a living cell is a crowded, heterogenuous, fluctuating environment. Hence, a major challenge in modeling intracellular transport is to analyze stochastic processes within complex environments. Broadly speaking, there are two basic mechanisms for intracellular transport: passive diffusion and motor-driven active transport. Diffusive transport can be formulated in terms of the motion of an overdamped Brownian particle. On the other hand, active transport requires chemical energy, usually in the form of adenosine triphosphate hydrolysis, and can be direction specific, allowing biomolecules to be transported long distances; this is particularly important in neurons due to their complex geometry. In this review a wide range of analytical methods and models of intracellular transport is presented. In the case of diffusive transport, narrow escape problems, diffusion to a small target, confined and single-file diffusion, homogenization theory, and fractional diffusion are considered. In the case of active transport, Brownian ratchets, random walk models, exclusion processes, random intermittent search processes, quasi-steady-state reduction methods, and mean-field approximations are considered. Applications include receptor trafficking, axonal transport, membrane diffusion, nuclear transport, protein-DNA interactions, virus trafficking, and the self-organization of subcellular structures. © 2013 American Physical Society.

  4. Goods Transport Modelling, Vol 1

    DEFF Research Database (Denmark)

    Petersen, Morten Steen (red.); Kristiansen, Jørgen

    The report is a study of data requirements and methodologies for goods transport. The study is intended to provide the basis for general discussion about the application of goods transport models in Denmark. The report provides an overview of different types of models and data availability....

  5. A national look at nitrate contamination of ground water

    Science.gov (United States)

    Nolan, Bernard T.; Ruddy, Barbara C.; Hitt, Kerie J.; Helsel, Dennis R.

    1998-01-01

    Ground water provides drinking water for more than one-half of the Nation's population (Solley and others, 1993), and is the sole source of drinking water for many rural communities and some large cities. In 1990, ground water accounted for 39 percent of water withdrawn for public supply for cities and towns and 96 percent of water withdrawn by self-supplied systems for domestic use.

  6. Petroleum contaminated ground-water: Remediation using activated carbon.

    OpenAIRE

    2006-01-01

    Ground-water contamination resulting from the leakage of crude oil and refined petroleum products during extraction and processing operations is a serious and a growing environmental problem in Nigeria. Consequently, a study of the use of activated carbon (AC) in the clean up was undertaken with the aim of reducing the water contamination to a more acceptable level. In the experiments described, crude-oil contamination of ground water was simulated under laboratory conditions using ground-wat...

  7. Radon-222 in the ground water of Chester County, Pennsylvania

    Science.gov (United States)

    Senior, Lisa A.

    1998-01-01

    Radon-222 concentrations in ground water in 31 geologic units in Chester County, Pa., were measured in 665 samples collected from 534 wells from 1986 to 1997. Chester County is underlain by schists, gneisses, quartzites, carbonates, sandstones, shales, and other rocks of the Piedmont Physiographic Province. On average, radon concentration was measured in water from one well per 1.4 square miles, throughout the 759 square-mile county, although the distribution of wells was not even areally or among geologic units. The median concentration of radon-222 in ground water from the 534 wells was 1,400 pCi/L (picocuries per liter). About 89 percent of the wells sampled contained radon-222 at concentrations greater than 300 pCi/L, and about 11 percent of the wells sampled contained radon-222 at concentrations greater than 5,000 pCi/L. The highest concentration measured was 53,000 pCi/L. Of the geologic units sampled, the median radon-222 concentration in ground water was greatest (4,400 pCi/L) in the Peters Creek Schist, the second most areally extensive formation in the county. Signifi- cant differences in the radon-222 concentrations in ground water among geologic units were observed. Generally, concentrations in ground water in schists, quartzites, and gneisses were greater than in ground water in anorthosite, carbonates, and ultramafic rocks. The distribution of radon-222 in ground water is related to the distribution of uranium in aquifer materials of the various rock types. Temporal variability in radon-222 concentrations in ground water does not appear to be greater than about a factor of two for most (75 percent) of wells sampled more than once but was observed to range up to almost a factor of three in water from one well. In water samples from this well, seasonal variations were observed; the maximum concentrations were measured in the fall and the minimum in the spring.

  8. Ground-Water Recharge in the Arid and Semiarid Southwestern United States

    Science.gov (United States)

    Stonestrom, David A.; Constantz, Jim; Ferre, Ty P.A.; Leake, Stanley A.

    2007-01-01

    Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Ni?o and Pacific Decadal Oscillations strongly, but irregularly, control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of naturally occurring multidecadal droughts unlike any in the modern instrumental record. Any anthropogenically induced climate change will likely reduce ground-water recharge through diminished snowpack at higher elevations. Future changes in El Ni?o and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Current land-use modifications influence ground-water recharge through vegetation, irrigation, and impermeable area. High mountain ranges bounding the study area?the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east?provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive Paleozoic aquifers in mountainous recharge areas

  9. Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms

    Science.gov (United States)

    Watanabe, N.; Harter, T.H.; Bergamaschi, B.A.

    2008-01-01

    Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin, which is given to lactating cows as a feed. By weight, monensin can be the most significant antibiotic used in a dairy farm. This study investigates the potential of monensin to move from dairy operations into the surrounding ground water. Using two dairy farms in California as study sites, we twice collected samples along the environmental pathway-from flush lanes, lagoon waters, and shallow ground water beneath the dairies and beneath its associated manured fields. Monensin concentrations were determined using solid-phase extraction and liquid chromatography-tandem mass spectrometry with positive electrospray ionization. Monensin was detected in all of the flush lane and lagoon water samples. Theoretical maximum concentration estimated from the actual dosing rate and the theoretical excretion rate assuming no attenuation was one order of magnitude greater than observed concentrations, suggesting significant attenuation in the manure collection and storage system. Monensin was also detected, at levels ranging from 0.04 to 0.39 microg L(-1), in some of the ground water samples underneath the production area of the dairy but not from the adjacent manured fields. Concentrations in ground water immediately downgradient of the lagoons were one to two orders of magnitude lower than the concentrations detected in lagoons, suggesting attenuation in the subsurface. The data suggest the possibility of monensin transport into shallow (2-5 m) alluvial ground water from dairy management units, including manure storage lagoons and freestalls occupied by heifers, lactating cows, and dry cows.

  10. Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms

    Science.gov (United States)

    Watanabe, N.; Harter, T.H.; Bergamaschi, B.A.

    2008-01-01

    Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin, which is given to lactating cows as a feed. By weight, monensin can be the most significant antibiotic used in a dairy farm. This study investigates the potential of monensin to move from dairy operations into the surrounding ground water. Using two dairy farms in California as study sites, we twice collected samples along the environmental pathway - from flush lanes, lagoon waters, and shallow ground water beneath the dairies and beneath its associated manured fields. Monensin concentrations were determined using solid-phase extraction and liquid chromatography-tandem mass spectrometry with positive electrospray ionization. Monensin was detected in all of the flush lane and lagoon water samples. Theoretical maximum concentration estimated from the actual dosing rate and the theoretical excretion rate assuming no attenuation was one order of magnitude greater than observed concentrations, suggesting significant attenuation in the manure collection and storage system. Monensin was also detected, at levels ranging from 0.04 to 0.39 ??g L-1, in some of the ground water samples underneath the production area of the dairy but not from the adjacent manured fields. Concentrations in ground water immediately downgradient of the lagoons were one to two orders of magnitude lower than the concentrations detected in lagoons, suggesting attenuation in the subsurface. The data suggest the possibility of monensin transport into shallow (2-5 m) alluvial ground water from dairy management units, including manure storage lagoons and freestalls occupied by heifers, lactating cows, and dry cows

  11. Identification of Naegleria fowleri in warm ground water aquifers.

    Science.gov (United States)

    Laseke, Ian; Korte, Jill; Lamendella, Regina; Kaneshiro, Edna S; Marciano-Cabral, Francine; Oerther, Daniel B

    2010-01-01

    The free-living amoeba Naegleria fowleri was identified as the etiological agent of primary amoebic meningoencephalitis that caused the deaths of two children in Peoria, Arizona, in autumn of 2002. It was suspected that the source of N. fowleri was the domestic water supply, which originates from ground water sources. In this study, ground water from the greater Phoenix Metropolitan area was tested for the presence of N. fowleri using a nested polymerase chain reaction approach. Phylogenetic analyses of 16S rRNA sequences of bacterial populations in the ground water were performed to examine the potential link between the presence of N. fowleri and bacterial groups inhabiting water wells. The results showed the presence of N. fowleri in five out of six wells sampled and in 26.6% of all ground water samples tested. Phylogenetic analyses showed that beta- and gamma-proteobacteria were the dominant bacterial populations present in the ground water. Bacterial community analyses revealed a very diverse community structure in ground water samples testing positive for N. fowleri.

  12. An imminent human resource crisis in ground water hydrology?

    Science.gov (United States)

    Stephens, Daniel B

    2009-01-01

    Anecdotal evidence, mostly from the United States, suggests that it has become increasingly difficult to find well-trained, entry-level ground water hydrologists to fill open positions in consulting firms and regulatory agencies. The future prospects for filling positions that require training in ground water hydrology are assessed by considering three factors: the market, the numbers of qualified students entering colleges and universities, and the aging of the existing workforce. The environmental and water resources consulting industry has seen continuous albeit variable growth, and demand for environmental scientists and hydrologists is expected to increase significantly. Conversely, students' interest and their enrollment in hydrology and water resources programs have waned in recent years, and the interests of students within these departments have shifted away from ground water hydrology in some schools. This decrease in the numbers of U.S. students graduating in hydrology or emphasizing ground water hydrology is coinciding with the aging of and pending retirement of ground water scientists and engineers in the baby boomer generation. We need to both trigger the imagination of students at the elementary school level so that they later want to apply science and math and communicate the career opportunities in ground water hydrology to those high school and college graduates who have acquired the appropriate technical background. Because the success of a consulting firm, research organization, or regulatory agency is derived from the skills and judgment of the employees, human resources will be an increasingly more critical strategic issue for many years.

  13. Ground-water conditions in Utah, spring of 2009

    Science.gov (United States)

    Burden, Carole B.; Allen, David V.; Rowland, Ryan C.; Fisher, Martel J.; Freeman, Michael L.; Downhour, Paul; Nielson, Ashley; Eacret, Robert J.; Myers, Andrew; Slaugh, Bradley A.; Swenson, Robert L.; Howells, James H.; Christiansen, Howard K.

    2009-01-01

    This is the forty-sixth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources and Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality, provide data to enable interested parties to maintain awareness of changing ground-water conditions. This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of ground water. Supplementary data are included in reports of this series only for those years or areas which are important to a discussion of changing ground-water conditions and for which applicable data are available.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 2008. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Resources and Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality. This report is available online at http://www.waterrights. utah.gov/techinfo/ and http://ut.water.usgs.gov/publications/ GW2009.pdf.

  14. Ground-water conditions in Utah, spring of 2003

    Science.gov (United States)

    Burden, Carole B.; Enright, Michael; Danner, M.R.; Fisher, M.J.; Haraden, Peter L.; Kenney, T.A.; Wilkowske, C.D.; Eacret, Robert J.; Downhour, Paul; Slaugh, B.A.; Swenson, R.L.; Howells, J.H.; Christiansen, H.K.

    2003-01-01

    This is the fortieth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources and Division of Water Rights, provide data to enable interested parties to maintain awareness of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of ground water. Supplementary data are included in reports of this series only for those years or areas which are important to a discussion of changing ground-water conditions and for which applicable data are available.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 2002. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights and Division of Water Resources.

  15. Ground-water conditions in Utah, spring of 2002

    Science.gov (United States)

    Burden, Carole B.; Enright, Michael; Danner, M.R.; Fisher, M.J.; Haraden, Peter L.; Kenney, T.A.; Wilkowske, C.D.; Eacret, Robert J.; Downhour, Paul; Slaugh, B.A.; Swenson, R.L.; Howells, J.H.; Christiansen, H.K.

    2002-01-01

    This is the thirty-ninth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources and Division of Water Rights, provide data to enable interested parties to maintain awareness of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of ground water. Supplementary data are included in reports of this series only for those years or areas which are important to a discussion of changing ground-water conditions and for which applicable data are available.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 2001. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights and Division of Water Resources.

  16. Ground-water conditions in Utah, spring of 2008

    Science.gov (United States)

    Burden, Carole B.; Allen, David V.; Danner, M.R.; Fisher, Martel J.; Freeman, Michael L.; Downhour, Paul; Wilkowske, C.D.; Eacret, Robert J.; Enright, Michael; Swenson, Robert L.; Howells, James H.; Christiansen, Howard K.

    2008-01-01

    This is the forty-fifth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources and Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality, provide data to enable interested parties to maintain awareness of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of ground water. Supplementary data are included in reports of this series only for those years or areas which are important to a discussion of changing ground-water conditions and for which applicable data are available.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 2007. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Resources and Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality. This report is available online at http://www.waterrights.utah.gov/techinfo/ and http://ut.water.usgs.gov/publications/GW2008.pdf.

  17. Ground-water conditions in Utah, spring of 2007

    Science.gov (United States)

    Burden, Carole B.; Allen, David V.; Danner, M.R.; Enright, Michael; Cillessen, J.L.; Gerner, S.J.; Eacret, Robert J.; Downhour, Paul; Slaugh, Bradley A.; Swenson, Robert L.; Howells, James H.; Christiansen, Howard K.; Fisher, Martel J.

    2007-01-01

    This is the forty-fourth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources and Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality, provide data to enable interested parties to maintain awareness of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to wells constructed for new appropriations of ground water. Supplementary data are included in reports of this series only for those years or areas which are important to a discussion of changing ground-water conditions and for which applicable data are available.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 2006. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Resources and Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality. This report is available online at http://www.waterrights.utah. gov/ and http://ut.water.usgs.gov/newUTAH/GW2007.pdf.

  18. Container Logistic Transport Planning Model

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2013-05-01

    Full Text Available The study proposed a stochastic method of container logistic transport in order to solve the unreasonable transportation’s problem and overcome the traditional models’ two shortcomings. Container transport has rapidly developed into a modern means of transportation because of their significant advantages. With the development, it also exacerbated the flaws of transport in the original. One of the most important problems was that the invalid transport had not still reduced due to the congenital imbalances of transportation. Container transport exacerbated the invalid transport for the empty containers. To solve the problem, people made many efforts, but they did not make much progress. There had two theoretical flaws by analyzing the previous management methods in container transport. The first one was the default empty containers inevitability. The second one was that they did not overall consider how to solve the problem of empty containers allocation. In order to solve the unreasonable transportation’s problem and overcome the traditional models’ two shortcomings, the study re-built the container transport planning model-gravity model. It gave the general algorithm and has analyzed the final result of model.

  19. Potential structural barriers to ground-water flow, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the surface traces of regional geologic structures designated as potential ground-water flow barriers in an approximately 45,000...

  20. Potential structural barriers to ground-water flow, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the surface traces of regional geologic structures designated as potential ground-water flow barriers in an approximately 45,000...

  1. Heat as a tool for studying the movement of ground water near streams

    Science.gov (United States)

    Stonestrom, David A.; Constantz, Jim

    2003-01-01

    and practical constraints. As an alternative, naturally occurring variations in temperature can be used to track (or trace) the heat carried by flowing water. The hydraulic transport of heat enables its use as a tracer. Differences between temperatures in the stream and surrounding sediments are now being analyzed to trace the movement of ground water to and from streams. As shown in the subsequent chapters of this circular, tracing the transport of heat leads to a better understanding of the magnitudes and mechanisms of stream/ground-water exchanges, and helps quantify the resulting effects on stream and streambed temperatures. Chapter 1 describes the general principals and procedures by which the natural transport of heat can be utilized to infer the movement of subsurface water near streams. This information sets the foundation for understanding the advanced applications in chapters 2 through 8. Each of these chapters provides a case study, using heat tracing as a tool, of interactions between surface water and ground water for a different location in the western United States. Technical details of the use of heat as an environmental tracer appear in appendices.

  2. Surface-Water and Ground-Water Interactions in the Central Everglades, Florida

    Science.gov (United States)

    Harvey, Judson W.; Newlin, Jessica T.; Krest, James M.; Choi, Jungyill; Nemeth, Eric A.; Krupa, Steven L.

    2004-01-01

    Recharge and discharge are hydrological processes that cause Everglades surface water to be exchanged for subsurface water in the peat soil and the underlying sand and limestone aquifer. These interactions are thought to be important to water budgets, water quality, and ecology in the Everglades. Nonetheless, relatively few studies of surface water and ground water interactions have been conducted in the Everglades, especially in its vast interior areas. This report is a product of a cooperative investigation conducted by the USGS and the South Florida Water Management District (SFWMD) aimed at developing and testing techniques that would provide reliable estimates of recharge and discharge in interior areas of WCA-2A (Water Conservation Area 2A) and several other sites in the central Everglades. The new techniques quantified flow from surface water to the subsurface (recharge) and the opposite (discharge) using (1) Darcy-flux calculations based on measured vertical gradients in hydraulic head and hydraulic conductivity of peat; (2) modeling transport through peat and decay of the naturally occurring isotopes 224Ra and 223Ra (with half-lives of 4 and 11 days, respectively); and (3) modeling transport and decay of naturally occurring and 'bomb-pulse' tritium (half-life of 12.4 years) in ground water. Advantages and disadvantages of each method for quantifying recharge and discharge were compared. In addition, spatial and temporal variability of recharge and discharge were evaluated and controlling factors identified. A final goal was to develop appropriately simplified (that is, time averaged) expressions of the results that will be useful in addressing a broad range of hydrological and ecological problems in the Everglades. Results were compared with existing information about water budgets from the South Florida Water Management Model (SFWMM), a principal tool used by the South Florida Water Management District to plan many of the hydrological aspects of the

  3. Optimization of ground-water withdrawal in the lower Fox River communities, Wisconsin

    Science.gov (United States)

    Walker, J.F.; Saad, D.A.; Krohelski, J.T.

    1998-01-01

    Pumping from closely spaced wells in the Central Brown County area and the Fox Cities area near the north shore of Lake Winnebago has resulted in the formation of deep cones of depression in the vicinity of the two pumping centers. Water-level measurements indicate there has been a steady decline in water levels in the vicinity of these two pumping centers for the past 50 years. This report describes the use of ground-water optimization modeling to efficiently allocate the ground-water resources in the Lower Fox River Valley. A 3-dimensional ground-water flow model was used along with optimization techniques to determine the optimal withdrawal rates for a variety of management alternatives. The simulations were conducted separately for the Central Brown County area and the Fox Cities area. For all simulations, the objective of the optimization was to maximize total ground-water withdrawals. The results indicate that ground water can supply nearly all of the projected 2030 demand for Central Brown County municipalities if all of the wells are managed (including the city of Green Bay), 8 new wells are installed, and the water-levels are allowed to decline to 100 ft below the bottom of the confining unit. Ground water can supply nearly all of the projected 2030 demand for the Fox Cities if the municipalities in Central Brown County convert to surface water; if Central Brown County municipalities follow the optimized strategy described above, there will be a considerable shortfall of available ground water for the Fox Cities communities. Relaxing the water-level constraint in a few wells, however, would likely result in increased availability of water. In all cases examined, optimization alternatives result in a rebound of the steady-state water levels due to projected 2030 withdrawal rates to levels at or near the bottom of the confining unit, resulting in increased well capacity. Because the simulations are steady-state, if all of the conditions of the model remain

  4. Distinguishing sources of ground water recharge by using delta2H and delta18O.

    Science.gov (United States)

    Blasch, Kyle W; Bryson, Jeannie R

    2007-01-01

    Stable isotope values of hydrogen and oxygen from precipitation and ground water samples were compared by using a volumetrically based mixing equation and stable isotope gradient to estimate the season and location of recharge in four basins. Stable isotopes were sampled at 11 precipitation sites of differing elevation during a 2-year period to quantify seasonal stable isotope contributions as a function of elevation. Supplemental stable isotope data collected by the International Atomic Energy Association during a 14-year period were used to reduce annual variability of the mean seasonal stable isotope data. The stable isotope elevation relationships and local precipitation elevation relationships were combined by using a digital elevation model to calculate the total volumetric contribution of water and stable isotope values as a function of elevation within the basins. The results of these precipitation calculations were compared to measured ground water stable isotope values at the major discharge points near the terminus of the basins. Volumetric precipitation contributions to recharge were adjusted to isolate contributing elevations. This procedure provides an improved representation of recharge contributions within the basins over conventional stable isotope methods. Stable isotope values from wells and springs at the terminus of each basin were used to infer the elevations of precipitation important for recharge of the regional ground water flow system. Ancillary climatic, geologic, and stable isotope values were used to further constrain the location where precipitation is entering the ground water flow system.

  5. Geology and ground-water resources of Goshen County, Wyoming; Chemical quality of the ground water

    Science.gov (United States)

    Rapp, J.R.; Visher, F.N.; Littleton, R.T.; Durum, W.H.

    1957-01-01

    Goshen County, which has an area of 2,186 square miles, lies in southeastern Wyoming. The purpose of this study was to evaluate the ground-water resources of the county by determining the character, thickness, and extent of the waterbearing materials; the source, occurrence, movement, quantity, and quality of the ground water; and the possibility of developing additional ground water. The rocks exposed in the area are sedimentary and range in age from Precambrian to Recent. A map that shows the areas of outcrop and a generalized section that summarizes the age, thickness, physical character, and water supply of these formations are included in the report. Owing to the great depths at which they lie beneath most of the county, the formations older than the Lance formation of Late Cretaceous age are not discussed in detail. The Lance formation, of Late Cretaceous age, which consists mainly of beds of fine-grained sandstone and shale, has a maximum thickness of about 1,400 feet. It yields water, which usually is under artesian pressure, to a large number of domestic and stock wells in the south-central part of the county. Tertiary rocks in the area include the Chadron and Brule formations of Oligocene age, the Arikaree formation of Miocene age, and channel deposits of Pliocene age. The Chadron formation is made up of two distinct units: a lower unit of highly variegated fluviatile deposits that has been found only in the report area; and an upper unit that is typical of the formation as it occurs in adjacent areas. The lower unit, which ranges in thickness from a knife edge to about 95 feet, is not known to yield water to wells, but its coarse-grained channel deposits probably would yield small quantities of water to wells. The upper unit, which ranges in thickness from a knife edge to about 150 feet, yields sufficient quantities of water for domestic and stock uses from channel deposits of sandstone under artesian pressure. The Brule formation, which is mainly a

  6. Modeling Np and Pu transport with a surface complexation model and spatially variant sorption capacities: Implications for reactive transport modeling and performance assessments of nuclear waste disposal sites

    Science.gov (United States)

    Glynn, P.D.

    2003-01-01

    One-dimensional (1D) geochemical transport modeling is used to demonstrate the effects of speciation and sorption reactions on the ground-water transport of Np and Pu, two redox-sensitive elements. Earlier 1D simulations (Reardon, 1981) considered the kinetically limited dissolution of calcite and its effect on ion-exchange reactions (involving 90Sr, Ca, Na, Mg and K), and documented the spatial variation of a 90Sr partition coefficient under both transient and steady-state chemical conditions. In contrast, the simulations presented here assume local equilibrium for all reactions, and consider sorption on constant potential, rather than constant charge, surfaces. Reardon's (1981) seminal findings on the spatial and temporal variability of partitioning (of 90Sr) are reexamined and found partially caused by his assumption of a kinetically limited reaction. In the present work, sorption is assumed the predominant retardation process controlling Pu and Np transport, and is simulated using a diffuse-double-layer-surface-complexation (DDLSC) model. Transport simulations consider the infiltration of Np- and Pu-contaminated waters into an initially uncontaminated environment, followed by the cleanup of the resultant contamination with uncontaminated water. Simulations are conducted using different spatial distributions of sorption capacities (with the same total potential sorption capacity, but with different variances and spatial correlation structures). Results obtained differ markedly from those that would be obtained in transport simulations using constant Kd, Langmuir or Freundlich sorption models. When possible, simulation results (breakthrough curves) are fitted to a constant K d advection-dispersion transport model and compared. Functional differences often are great enough that they prevent a meaningful fit of the simulation results with a constant K d (or even a Langmuir or Freundlich) model, even in the case of Np, a weakly sorbed radionuclide under the

  7. Preliminary estimates of residence times and apparent ages of ground water in the Chesapeake Bay watershed, and water-quality data from a survey of springs

    Science.gov (United States)

    Focazio, Michael J.; Plummer, L. Neil; Bohlke, John K.; Busenberg, Eurybiades; Bachman, L. Joseph; Powars, David S.

    1998-01-01

    Knowledge of the residence times of the ground-water systems in Chesapeake Bay watershed helps resource managers anticipate potential delays between implementation of land-management practices and any improve-ments in river and estuary water quality. This report presents preliminary estimates of ground-water residence times and apparent ages of water in the shallow aquifers of the Chesapeake Bay watershed. A simple reservoir model, published data, and analyses of spring water were used to estimate residence times and apparent ages of ground-water discharge. Ranges of aquifer hydraulic characteristics throughout the Bay watershed were derived from published literature and were used to estimate ground-water residence times on the basis of a simple reservoir model. Simple combinations of rock type and physiographic province were used to delineate hydrogeomorphic regions (HGMR?s) for the study area. The HGMR?s are used to facilitate organization and display of the data and analyses. Illustrations depicting the relation of aquifer characteristics and associated residence times as a continuum for each HGMR were developed. In this way, the natural variation of aquifer characteristics can be seen graphically by use of data from selected representative studies. Water samples collected in September and November 1996, from 46 springs throughout the watershed were analyzed for chlorofluorocarbons (CFC?s) to estimate the apparent age of ground water. For comparison purposes, apparent ages of water from springs were calculated assuming piston flow. Additi-onal data are given to estimate apparent ages assuming an exponential distribution of ages in spring discharge. Additionally, results from previous studies of CFC-dating of ground water from other springs and wells in the watershed were compiled. The CFC data, and the data on major ions, nutrients, and nitrogen isotopes in the water collected from the 46 springs are included in this report. The apparent ages of water

  8. Ground water dependence of endangered ecosystems: Nebraska's eastern saline wetlands.

    Science.gov (United States)

    Harvey, F Edwin; Ayers, Jerry F; Gosselin, David C

    2007-01-01

    Many endangered or threatened ecosystems depend on ground water for their survival. Nebraska's saline wetlands, home to a number of endangered species, are ecosystems whose development, sustenance, and survival depend on saline ground water discharge at the surface. This study demonstrates that the saline conditions present within the eastern Nebraska saline wetlands result from the upwelling of saline ground water from within the underlying Dakota Aquifer and deeper underlying formations of Pennsylvanian age. Over thousands to tens of thousands of years, saline ground water has migrated over regional scale flowpaths from recharge zones in the west to the present-day discharge zones along the saline streams of Rock, Little Salt, and Salt Creeks in Lancaster and Saunders counties. An endangered endemic species of tiger beetle living within the wetlands has evolved under a unique set of hydrologic conditions, is intolerant to recent anthropogenic changes in hydrology and salinity, and is therefore on the brink of extinction. As a result, the fragility of such systems demands an even greater understanding of the interrelationships among geology, hydrology, water chemistry, and biology than in less imperiled systems where adaptation is more likely. Results further indicate that when dealing with ground water discharge-dependent ecosystems, and particularly those dependent on dissolved constituents as well as the water, wetland management must be expanded outside of the immediate surface location of the visible ecosystem to include areas where recharge and lateral water movement might play a vital role in wetland hydrologic and chemical mixing dynamics.

  9. Global optimal design of ground water monitoring network using embedded kriging.

    Science.gov (United States)

    Dhar, Anirban; Datta, Bithin

    2009-01-01

    We present a methodology for global optimal design of ground water quality monitoring networks using a linear mixed-integer formulation. The proposed methodology incorporates ordinary kriging (OK) within the decision model formulation for spatial estimation of contaminant concentration values. Different monitoring network design models incorporating concentration estimation error, variance estimation error, mass estimation error, error in locating plume centroid, and spatial coverage of the designed network are developed. A big-M technique is used for reformulating the monitoring network design model to a linear decision model while incorporating different objectives and OK equations. Global optimality of the solutions obtained for the monitoring network design can be ensured due to the linear mixed-integer programming formulations proposed. Performances of the proposed models are evaluated for both field and hypothetical illustrative systems. Evaluation results indicate that the proposed methodology performs satisfactorily. These performance evaluation results demonstrate the potential applicability of the proposed methodology for optimal ground water contaminant monitoring network design.

  10. Regional estimation of total recharge to ground water in Nebraska.

    Science.gov (United States)

    Szilagyi, Jozsef; Harvey, F Edwin; Ayers, Jerry F

    2005-01-01

    Naturally occurring long-term mean annual recharge to ground water in Nebraska was estimated by a novel water-balance approach. This approach uses geographic information systems (GIS) layers of land cover, elevation of land and ground water surfaces, base recharge, and the recharge potential in combination with monthly climatic data. Long-term mean recharge > 140 mm per year was estimated in eastern Nebraska, having the highest annual precipitation rates within the state, along the Elkhorn, Platte, Missouri, and Big Nemaha River valleys where ground water is very close to the surface. Similarly high recharge values were obtained for the Sand Hills sections of the North and Middle Loup, as well as Cedar River and Beaver Creek valleys due to high infiltration rates of the sandy soil in the area. The westernmost and southwesternmost parts of the state were estimated to typically receive recharge a year.

  11. Coliphages and bacteria in ground water from Tehran, Iran

    Energy Technology Data Exchange (ETDEWEB)

    Shariatpanahi, M.; Anderson, A.C.

    1987-07-01

    The purpose of this study was to examine the microbial quality of Tehran's ground water and selected springs, using coliphages and selected bacteria as indicator organisms. The water table in Tehran varies from approximately 160 meters in the north to approximately 5 meters in the south. Individual wells and subterranean man-made aqueducts (qanate) tap the ground water. Since Tehran lacks municipal sewage facilities, waste disposal is by means of seepage pits, privies and leaching cesspools. There is potential for waste from these sites to leach into the ground water, particularly in the south where the water table is near the surface and the clay content of the soil holds moisture during periods of heavy rainfall.

  12. Geochemical and isotopic composition of ground water with emphasis on sources of sulfate in the upper Floridan Aquifer in parts of Marion, Sumter, and Citrus counties, Florida

    Science.gov (United States)

    Sacks, Laura A.

    1996-01-01

    In inland areas of northwest central Florida, sulfate concentrations in the Upper Floridan aquifer are extremely variable and sometimes exceed drinking water standards (250 milligrams per liter). This is unusual because the aquifer is unconfined and near the surface, allowing for active recharge. The sources of sulfate and geochemical processes controlling ground-water composition were evaluated in this area. Water was sampled from thirty-three wells in parts of Marion, Sumter, and Citrus Counties, within the Southwest Florida Water Management District; these included at least a shallow and a deep well at fifteen separate locations. Ground water was analyzed for major ions, selected trace constituents, dissolved organic carbon, and stable isotopes (sulfur-34 of sulfate and sulfide, carbon-13 of inorganic carbon, deuterium, and oxygen-18). Sulfate concentrations ranged from less than 0.2 to 1,400 milligrams per liter, with higher sulfate concentrations usually in water from deeper wells. The samples can be categorized into a low sulfate group (less than 30 milligrams per liter) and a high sulfate group (greater than 30 milligrams per liter). For the high sulfate water, concentrations of calcium and magnesium increased concurrently with sulfate. Chemical and isotopic data and mass-balance modeling indicate that the composition of high sulfate waters is controlled by dedolomitization reactions (dolomite dissolution and calcite precipitation, driven by dissolution of gypsum). Gypsum occurs deeper in the aquifer than open intervals of sampled wells. Upward flow has been documented in deeper parts of the aquifer in the study area, which may be driven by localized discharge areas or rapid flow in shallow parts of the aquifer. Mixing between shallow ground water and sulfate-rich water that dissolved gypsum at the base of the aquifer is probably responsible for the range of concentrations observed in the study area. Other solutes that increased with sulfate apparently

  13. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    Energy Technology Data Exchange (ETDEWEB)

    P. Tucci

    2001-12-20

    This Analysis/Model Report (AMR) documents an updated analysis of water-level data performed to provide the saturated-zone, site-scale flow and transport model (CRWMS M&O 2000) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for model calibration. The previous analysis was presented in ANL-NBS-HS-000034, Rev 00 ICN 01, Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model (USGS 2001). This analysis is designed to use updated water-level data as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain. The objectives of this revision are to develop computer files containing (1) water-level data within the model area (DTN: GS010908312332.002), (2) a table of known vertical head differences (DTN: GS0109083 12332.003), and (3) a potentiometric-surface map (DTN: GS010608312332.001) using an alternate concept from that presented in ANL-NBS-HS-000034, Rev 00 ICN 01 for the area north of Yucca Mountain. The updated water-level data include data obtained from the Nye County Early Warning Drilling Program (EWDP) and data from borehole USW WT-24. In addition to being utilized by the SZ site-scale flow and transport model, the water-level data and potentiometric-surface map contained within this report will be available to other government agencies and water users for ground-water management purposes. The potentiometric surface defines an upper boundary of the site-scale flow model, as well as provides information useful to estimation of the magnitude and direction of lateral ground-water flow within the flow system. Therefore, the analysis documented in this revision is important to SZ flow and transport calculations in support of total system performance assessment.

  14. Cost analysis of ground-water supplies in the North Atlantic region, 1970

    Science.gov (United States)

    Cederstrom, Dagfin John

    1973-01-01

    The cost of municipal and industrial ground water (or, more specifically, large supplies of ground water) at the wellhead in the North Atlantic Region in 1970 generally ranged from 1.5 to 5 cents per thousand gallons. Water from crystalline rocks and shale is relatively expensive. Water from sandstone is less so. Costs of water from sands and gravels in glaciated areas and from Coastal Plain sediments range from moderate to very low. In carbonate rocks costs range from low to fairly high. The cost of ground water at the wellhead is low in areas of productive aquifers, but owing to the cost of connecting pipe, costs increase significantly in multiple-well fields. In the North Atlantic Region, development of small to moderate supplies of ground water may offer favorable cost alternatives to planners, but large supplies of ground water for delivery to one point cannot generally be developed inexpensively. Well fields in the less productive aquifers may be limited by costs to 1 or 2 million gallons a day, but in the more favorable aquifers development of several tens of millions of gallons a day may be practicable and inexpensive. Cost evaluations presented cannot be applied to any one specific well or specific site because yields of wells in any one place will depend on the local geologic and hydrologic conditions; however, with such cost adjustments as may be necessary, the methodology presented should have wide applicability. Data given show the cost of water at the wellhead based on the average yield of several wells. The cost of water delivered by a well field includes costs of connecting pipe and of wells that have the yields and spacings specified. Cost of transport of water from the well field to point of consumption and possible cost of treatment are not evaluated. In the methodology employed, costs of drilling and testing, pumping equipment, engineering for the well field, amortization at 5% percent interest, maintenance, and cost of power are considered. The

  15. Hydrogeologic setting, hydraulic properties, and ground-water flow at the O-Field area of Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Banks, W.S.; Smith, B.S.; Donnelly, C.A.

    1996-01-01

    The U.S. Army disposed chemical agents, laboratory materials, and unexploded ordnance at O-Field in the Edgewood area of Aberdeen Proving Ground, Maryland, from before World War II until at least the 1950's. Soil, ground water, surface water,and wetland sediments in the O-Field area were contaminated from the disposal activity. A ground-water-flow model of the O-Field area was constructed by the U.S. Geological Survey (USGS) in 1989 to simulate flow in the central and southern part of the Gunpowder Neck. The USGS began an additional study of the contamination in the O-Field area in cooperation with the U.S. Army in 1990 to (1) further define the hydrogeologic framework of the O-Field area, (2) characterize the hydraulic properties of the aquifers and confining units, and (3) define ground-water flow paths at O-Field based on the current data and simulations of ground-water flow. A water-table aquifer, an upper confining unit, and an upper confined aquifer comprise the shallow ground-water aquifer system of the O-Field area. A lower confining unit, through which ground-water movement is negligible, is considered a lower boundary to the shallow aquifer system. These units are all part of the Pleistocene Talbot Formation. The model developed in the previous study was redesigned using the data collected during this study and emphasized New O-Field. The current steady-state model was calibrated to water levels of June 1993. The rate of ground-water flow calculated by the model was approximately 0.48 feet per day (ft/d) and the rate determined from chlorofluorocarbon dates was approximately 0.39 ft/d.

  16. Geophysical Methods for Investigating Ground-Water Recharge

    Science.gov (United States)

    Ferre, Ty P.A.; Binley, Andrew M.; Blasch, Kyle W.; Callegary, James B.; Crawford, Steven M.; Fink, James B.; Flint, Alan L.; Flint, Lorraine E.; Hoffmann, John P.; Izbicki, John A.; Levitt, Marc T.; Pool, Donald R.; Scanlon, Bridget R.

    2007-01-01

    While numerical modeling has revolutionized our understanding of basin-scale hydrologic processes, such models rely almost exclusively on traditional measurements?rainfall, streamflow, and water-table elevations?for calibration and testing. Model calibration provides initial estimates of ground-water recharge. Calibrated models are important yet crude tools for addressing questions about the spatial and temporal distribution of recharge. An inverse approach to recharge estimation is taken of necessity, due to inherent difficulties in making direct measurements of flow across the water table. Difficulties arise because recharging fluxes are typically small, even in humid regions, and because the location of the water table changes with time. Deep water tables in arid and semiarid regions make recharge monitoring especially difficult. Nevertheless, recharge monitoring must advance in order to improve assessments of ground-water recharge. Improved characterization of basin-scale recharge is critical for informed water-resources management. Difficulties in directly measuring recharge have prompted many efforts to develop indirect methods. The mass-balance approach of estimating recharge as the residual of generally much larger terms has persisted despite the use of increasing complex and finely gridded large-scale hydrologic models. Geophysical data pertaining to recharge rates, timing, and patterns have the potential to substantially improve modeling efforts by providing information on boundary conditions, by constraining model inputs, by testing simplifying assumptions, and by identifying the spatial and temporal resolutions needed to predict recharge to a specified tolerance in space and in time. Moreover, under certain conditions, geophysical measurements can yield direct estimates of recharge rates or changes in water storage, largely eliminating the need for indirect measures of recharge. This appendix presents an overview of physically based, geophysical methods

  17. UNCERT: geostatistics, uncertainty analysis and visualization software applied to groundwater flow and contaminant transport modeling

    Science.gov (United States)

    Wingle, William L.; Poeter, Eileen P.; McKenna, Sean A.

    1999-05-01

    UNCERT is a 2D and 3D geostatistics, uncertainty analysis and visualization software package applied to ground water flow and contaminant transport modeling. It is a collection of modules that provides tools for linear regression, univariate statistics, semivariogram analysis, inverse-distance gridding, trend-surface analysis, simple and ordinary kriging and discrete conditional indicator simulation. Graphical user interfaces for MODFLOW and MT3D, ground water flow and contaminant transport models, are provided for streamlined data input and result analysis. Visualization tools are included for displaying data input and output. These include, but are not limited to, 2D and 3D scatter plots, histograms, box and whisker plots, 2D contour maps, surface renderings of 2D gridded data and 3D views of gridded data. By design, UNCERT's graphical user interface and visualization tools facilitate model design and analysis. There are few built in restrictions on data set sizes and each module (with two exceptions) can be run in either graphical or batch mode. UNCERT is in the public domain and is available from the World Wide Web with complete on-line and printable (PDF) documentation. UNCERT is written in ANSI-C with a small amount of FORTRAN77, for UNIX workstations running X-Windows and Motif (or Lesstif). This article discusses the features of each module and demonstrates how they can be used individually and in combination. The tools are applicable to a wide range of fields and are currently used by researchers in the ground water, mining, mathematics, chemistry and geophysics, to name a few disciplines.

  18. Shallow ground-water conditions, Tom Green County, Texas

    Science.gov (United States)

    Lee, J.N.

    1986-01-01

    Most of the water needs of Tom Green County, Texas, are supplied by ground water; however, the city of San Angelo is supplied by surface water. Groundwater withdrawals during 1980 (latest year for which data are available) in Tom Green County totaled about 15,300 acre-feet, all derived from shallow aquifers. Shallow aquifers in this report refer to the ground-water system generally less than 400 feet deep that contains water with less than a 10,000 milligrams per liter concentration of dissolved solids; aquifers comprising this system include: The Leona, Comanche Peak, Trinity, Blaine, San Angelo, Choza, Bullwagon, Vale, Standpipe, and Arroyo aquifers.

  19. Apparatus for ground water chemistry investigations in field caissons

    Energy Technology Data Exchange (ETDEWEB)

    Cokal, E.J.; Stallings, E.; Walker, R.; Nyhan, J.W.; Polzer, W.L.; Essington, E.H.

    1985-01-01

    Los Alamos is currently in its second season of ground water chemistry and hydrology experimentation in a field facility that incorporates clusters of six, 3-meter-diameter by 6-meter-deep, soil-filled caissons and required ancillaries. Initial experience gained during the 1983 field season indicated the need for further development of the technology of this type of experimentation supporting hydrologic waste management research. Uniform field application of water/matrix solutions to the caisson, matrix and tracer solution blending/storage, and devices for ground water sampling are discussed.

  20. 40 CFR Appendix Ix to Part 264 - Ground-Water Monitoring List

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Ground-Water Monitoring List IX... Pt. 264, App. IX Appendix IX to Part 264—Ground-Water Monitoring List Ground-Water Monitoring List... species in the ground water that contain this element are included. 3 CAS index names are those used in...

  1. Fracture control of ground water flow and water chemistry in a rock aquitard.

    Science.gov (United States)

    Eaton, Timothy T; Anderson, Mary P; Bradbury, Kenneth R

    2007-01-01

    There are few studies on the hydrogeology of sedimentary rock aquitards although they are important controls in regional ground water flow systems. We formulate and test a three-dimensional (3D) conceptual model of ground water flow and hydrochemistry in a fractured sedimentary rock aquitard to show that flow dynamics within the aquitard are more complex than previously believed. Similar conceptual models, based on regional observations and recently emerging principles of mechanical stratigraphy in heterogeneous sedimentary rocks, have previously been applied only to aquifers, but we show that they are potentially applicable to aquitards. The major elements of this conceptual model, which is based on detailed information from two sites in the Maquoketa Formation in southeastern Wisconsin, include orders of magnitude contrast between hydraulic diffusivity (K/S(s)) of fractured zones and relatively intact aquitard rock matrix, laterally extensive bedding-plane fracture zones extending over distances of over 10 km, very low vertical hydraulic conductivity of thick shale-rich intervals of the aquitard, and a vertical hydraulic head profile controlled by a lateral boundary at the aquitard subcrop, where numerous surface water bodies dominate the shallow aquifer system. Results from a 3D numerical flow model based on this conceptual model are consistent with field observations, which did not fit the typical conceptual model of strictly vertical flow through an aquitard. The 3D flow through an aquitard has implications for predicting ground water flow and for planning and protecting water supplies.

  2. Status Of Physico-Chemical Parameter Of Ground Water Of Gorakhpur City U.P. India

    Directory of Open Access Journals (Sweden)

    Priyanka Chaudhary

    2015-08-01

    Full Text Available ABSTRACT The ground water is most prime water which has multipurpose use ranging from drinking to industrial and agricultural uses. The continuously increase in the level of pollution of water is a serious problem. The city of Gorakhpur is not untouched with this serious issue .The pollution level of the major water sources in and around the city is increase rapidly. The main objective of the present study is to study the variation of ground water quality in Gorakhpur district by collecting 20 samples of water from hand pump from 20 locations well distributed with in Gorakhpur district were analyzed for different parameters such as pH electric conductivity chloride total free chlorine hardness fluoride nitrate iron Turbidity potassium. Groundwater is polluted from seepage pits refuse dumps septic tanks barnyards manures transport accident and different pollutant. Important sources of ground water pollution are sewage is dumped in shallow soak pits. It gives rise to cholera hepatitis dysenteries etc. especially in areas with high water table.

  3. Hydrologic and biogeochemical controls of river subsurface solutes under agriculturally enhanced ground water flow

    Science.gov (United States)

    Wildman, R.A.; Domagalski, J.L.; Hering, J.G.

    2009-01-01

    The relative influences of hydrologic processes and biogeochemistry on the transport and retention of minor solutes were compared in the riverbed of the lower Merced River (California, USA). The subsurface of this reach receives ground water discharge and surface water infiltration due to an altered hydraulic setting resulting from agricultural irrigation. Filtered ground water samples were collected from 30 drive point locations in March, June, and October 2004. Hydrologic processes, described previously, were verified by observations of bromine concentrations; manganese was used to indicate redox conditions. The separate responses of the minor solutes strontium, barium, uranium, and phosphorus to these influences were examined. Correlation and principal component analyses indicate that hydrologic processes dominate the distribution of trace elements in the ground water. Redox conditions appear to be independent of hydrologic processes and account for most of the remaining data variability. With some variability, major processes are consistent in two sampling transects separated by 100 m. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  4. Modelling of Transport Projects Uncertainties

    DEFF Research Database (Denmark)

    Salling, Kim Bang; Leleur, Steen

    2009-01-01

    This paper proposes a new way of handling the uncertainties present in transport decision making based on infrastructure appraisals. The paper suggests to combine the principle of Optimism Bias, which depicts the historical tendency of overestimating transport related benefits and underestimating...... investment costs, with a quantitative risk analysis based on Monte Carlo simulation and to make use of a set of exploratory scenarios. The analysis is carried out by using the CBA-DK model representing the Danish standard approach to socio-economic cost-benefit analysis. Specifically, the paper proposes......-based graphs which function as risk-related decision support for the appraised transport infrastructure project....

  5. Ground water heat pumps and cooling with ground water basins as seasonal storage; Grundvandsvarmepumper og -koeling med grundvandsmagasiner som saesonlager

    Energy Technology Data Exchange (ETDEWEB)

    2008-04-15

    Ground water temperature is constant all the year round, in Denmark approximately 9 deg. C, which is ideal for a number of cooling purposes including cooling of buildings. The structures in which the ground water flows (sand, gravel and chalk) are efficient for storing coldness and heat over longer periods. By using seasonal storage of low-temperature heat and coldness in ground water layers close to the terrain it is feasible to reach profitable energy savings of up to 90% for cooling and heating of e.g. hotels, airports, shopping malls, office buildings and other larger buildings. At the same time the large energy savings means major reduction of CO{sub 2} emissions. (BA)

  6. Maps showing ground-water levels, springs, and depth to ground water, Basin and Range Province, Texas

    Science.gov (United States)

    Brady, B.T.; Bedinger, M.S.; Mulvihill, D.A.; Mikels, John; Langer, W.H.

    1984-01-01

    This report on ground-water levels, springs, and depth to ground water in the Basin and Range province of Texas (see index map) was prepared as part of a program of the U.S. Geological Survey to identify prospective regions for further study relative to isolation of high-level nuclear waste (Bedinger, Sargent, and Reed, 1984), utilizing program guidelines defined in Sargent and Bedinger (1984). Also included in this report are selected references on pertinent geologic and hydrologic studies of the region. Other map reports in this series contain detailed data on ground-water quality, surface distribution of selected rock types, tectonic conditions, areal geophysics, Pleistocene lakes and marshes, and mineral and energy resources.

  7. Ground water heat pumps and cooling with ground water basins as seasonal storage; Grundvandsvarmepumper og -koeling med grundvandsmagasiner som saesonlager

    Energy Technology Data Exchange (ETDEWEB)

    2008-04-15

    Ground water temperature is constant all the year round, in Denmark approximately 9 deg. C, which is ideal for a number of cooling purposes including cooling of buildings. The structures in which the ground water flows (sand, gravel and chalk) are efficient for storing coldness and heat over longer periods. By using seasonal storage of low-temperature heat and coldness in ground water layers close to the terrain it is feasible to reach profitable energy savings of up to 90% for cooling and heating of e.g. hotels, airports, shopping malls, office buildings and other larger buildings. At the same time the large energy savings means major reduction of CO{sub 2} emissions. (BA)

  8. Next Generation Transport Phenomenology Model

    Science.gov (United States)

    Strickland, Douglas J.; Knight, Harold; Evans, J. Scott

    2004-01-01

    This report describes the progress made in Quarter 3 of Contract Year 3 on the development of Aeronomy Phenomenology Modeling Tool (APMT), an open-source, component-based, client-server architecture for distributed modeling, analysis, and simulation activities focused on electron and photon transport for general atmospheres. In the past quarter, column emission rate computations were implemented in Java, preexisting Fortran programs for computing synthetic spectra were embedded into APMT through Java wrappers, and work began on a web-based user interface for setting input parameters and running the photoelectron and auroral electron transport models.

  9. The Influence of Ground Water on Stream Restoration Following Dam Removal

    Science.gov (United States)

    Constantz, J.; Essaid, H.

    2003-12-01

    With the exception of ground-water seepage beneath dams and the resulting impact on structural failure, there is a void of work directly examining the downstream impacts of dams from the perspective of ground-water/surface-water interaction. This work considers alterations in an alluvial basin caused by: (1) erection of a dam upstream, (2) followed by ground-water pumping in the basin, and (3) dam removal. Theoretical results predict that when dams are removed in developed ground-water basins, downstream baseflows may be greatly reduced relative to natural baseflows, as a result of lower water table elevations in the developed basin relative to the natural setting. Without the dam as a `safety valve' providing extra streamflow during low-flow seasons, there is a real potential for ephemeral conditions downstream of the previous location of the dam as the dry season progresses. MODFLOW simulations are used to test these theoretical results, by quantifying the impact of dam removal on downstream surface water and ground water. The simulations incorporate an improved stream-aquifer interaction and streamflow routing package to represent movement of water in the vadose zone between the stream and a lowered water table. An idealized MODFLOW model with the new stream package has been constructed, which extends from the upland bedrock headwaters of a stream to the downstream sediment-filled basin. The model domain is 180 km long, 15 km wide, and 2.2 km deep, including a stream with a potential length of 180 km. In the upper reaches, the stream is divided into a north, south, and main stem with their confluence upstream of a dam situated in the domain above the bedrock/basin contact. Horizontal discretization is 1000 m in the direction parallel to the stream, 200 to 600 m perpendicular to the stream, and vertical discretization is 100 m. This modeling framework affords the opportunity to examine a variety of cases with and without the presence of an upstream dam. Initial

  10. Ground water in the southeastern Uinta Basin, Utah and Colorado

    Science.gov (United States)

    Holmes, Walter F.; Kimball, Briant A.

    1987-01-01

    The potential for developing oil-shale resources in the southeastern Uinta Basin of Utah and Colorado has created the need for information on the quantity and quality of water available in the area. This report describes the availability and chemical quality of ground water, which might provide a source or supplement of water supply for an oil-shale industry. Ground water in the southeastern Uinta Basin occurs in three major aquifers. Alluvial aquifers of small areal extent are present in valley-fill deposits of six major drainages. Consolidated-rock aquifers include the bird?s-nest aquifer in the Parachute Creek Member of the Green River Formation, which is limited to the central part of the study area; and the Douglas Creek aquifer, which includes parts of the Douglas Creek Member of the Green River Formation and parts of the intertonguing Renegade Tongue of the Wasatch Formation; this aquifer underlies most of the study area. The alluvial aquifers are recharged by infiltration of streamflow and leakage from consolidated-rock aquifers. Recharge is estimated to average about 32,000 acre-feet per year. Discharge from alluvial aquifers, primarily by evapotranspiration, also averages about 32,000 acre-feet per year. The estimated volume of recoverable water in storage in alluvial aquifers is about 200,000 acre-feet. Maximum yields to individual wells are less than 1,000 gallons per minute. Recharge to the bird's-nest aquifer, primarily from stream infiltration and downward leakage from the overlying Uinta Formation, is estimated to average 670 acre-feet per year. Discharge from the bird's-nest aquifer, which is primarily by seepage to Bitter Creek and the White River, is estimated to be at 670 acre-feet per year. The estimated volume of recoverable water in storage in the bird's-nest aquifer is 1.9 million acre-feet. Maximum yields to individual wells in some areas may be as much as 5,000 gallons per minute. A digital-computer model of the flow system was used to

  11. SUPERFUND GROUND WATER ISSUE - ACCURACY OF DEPTH TO WATER MEASUREMENTS

    Science.gov (United States)

    Accuracy of depth to water measurements is an issue identified by the Forum as a concern of Superfund decision-makers as they attempt to determine directions of ground-water flow, areas of recharge of discharge, the hydraulic characteristics of aquifers, or the effects of manmade...

  12. Influence on shallow ground water by nitrogen in polluted river

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-ping; CAO Lian-hai; CHEN Xiao-gang; SHEN Zhao-li; ZHONG Zuo-shen

    2008-01-01

    The main purpose of the research is to discuss the influence on ground water by NH4-N in polluted river and river bed. In the lab-scale experiment three kinds of natural sand were chosen as infiltration medium, and polluted rivers were simulated by domestic sewage, after 10-month sand column test it was found that NH4-N came to adsorption sa-turation on the 17th day in coarse sand and on the 130~140th day in medium sand, then had a higher effluent concentration because of desorption. It is concluded that NH4-N eas-ily moved to ground water. When the concentration of NH4-N in Liangshui River were 46.86, 26.95 mg/L, that in groundwater are less than 1.10 mg/L. It is found that Liangshui River have a little influence on groundwater because of bottom mud, thickness and char-acter of the infiltration medium under the river bed and seepage quantity of river water.Clean water leaching test states that after the silt is cleared away and clean water is poured, NH4-N in the penetration media under the polluted river is obviously carried into ground water, and ground water is polluted secondly.

  13. A proposed ground-water quality monitoring network for Idaho

    Science.gov (United States)

    Whitehead, R.L.; Parliman, D.J.

    1979-01-01

    A ground water quality monitoring network is proposed for Idaho. The network comprises 565 sites, 8 of which will require construction of new wells. Frequencies of sampling at the different sites are assigned at quarterly, semiannual, annual, and 5 years. Selected characteristics of the water will be monitored by both laboratory- and field-analysis methods. The network is designed to: (1) Enable water managers to keep abreast of the general quality of the State 's ground water, and (2) serve as a warning system for undesirable changes in ground-water quality. Data were compiled for hydrogeologic conditions, ground-water quality, cultural elements, and pollution sources. A ' hydrologic unit priority index ' is used to rank 84 hydrologic units (river basins or segments of river basins) of the State for monitoring according to pollution potential. Emphasis for selection of monitoring sites is placed on the 15 highest ranked units. The potential for pollution is greatest in areas of privately owned agricultural land. Other areas of pollution potential are residential development, mining and related processes, and hazardous waste disposal. Data are given for laboratory and field analyses, number of site visits, manpower, subsistence, and mileage, from which costs for implementing the network can be estimated. Suggestions are made for data storage and retrieval and for reporting changes in water quality. (Kosco-USGS)

  14. Ground Water Arsenic Contamination: A Local Survey in India

    Science.gov (United States)

    Kumar, Arun; Rahman, Md. Samiur; Iqubal, Md. Asif; Ali, Mohammad; Niraj, Pintoo Kumar; Anand, Gautam; Kumar, Prabhat; Abhinav; Ghosh, Ashok Kumar

    2016-01-01

    Background: In the present times, arsenic poisoning contamination in the ground water has caused lots of health-related problems in the village population residing in middle Gangetic plain. In Bihar, about 16 districts have been reported to be affected with arsenic poisoning. For the ground water and health assessment, Simri village of Buxar district was undertaken which is a flood plain region of river Ganga. Methods: In this study, 322 water samples were collected for arsenic estimation, and their results were analyzed. Furthermore, the correlation between arsenic contamination in ground water with depth and its distance from river Ganga were analyzed. Results are presented as mean ± standard deviation and total variation present in a set of data was analyzed through one-way analysis of variance. The difference among mean values has been analyzed by applying Dunnett's test. The criterion for statistical significance was set at P arsenic concentration in hand pumps. Furthermore, a correlation between the arsenic concentration with the depth of the hand pumps and the distance from the river Ganga was also a significant study. Conclusions: The present study concludes that in Simri village there is high contamination of arsenic in ground water in all the strips. Such a huge population is at very high risk leading the village on the verge of causing health hazards among them. Therefore, an immediate strategy is required to combat the present problem. PMID:27625765

  15. The Use Of Permeable Concrete For Ground Water Recharge

    Directory of Open Access Journals (Sweden)

    Akshay Tejankar

    2016-09-01

    Full Text Available In order to develop Smart Cities in India, we need to develop smart technologies and smart construction materials. Permeable concrete an innovative material is environment friendly and a smart material which can be used for construction of several structures. In India, the ground water table is decreasing at a faster rate due to reduction in ground water recharge. These days, the vegetation cover is replaced by infrastructure hence the water gets very less opportunity to infiltrate itself into the soil. If the permeable concrete which has a high porosity is used for the construction of pavements, walking tracks, parking lots, well lining, etc. then it can reduce the runoff from the site and help in the ground water recharge. Such type of smart materials will play an important role for Indian conditions where government is putting lot of efforts to implement ground water recharging techniques. During the research work, the runoff for a particular storm was calculated for a bitumen pavement on a sloping ground. Later after studying the various topographical features, the traffic intensity and the rainfall for that particular area, the concrete was designed and tested for the different proportion and thus the mix design for the permeable concrete was finalized based upon its permeability and strength characteristics. Later by using this permeable concrete the infiltration and runoff for the same storm was compared and studied. The research paper will thus give an account of the properties of permeable concrete where it can be used over an existing road.

  16. Water law, with special reference to ground water

    Science.gov (United States)

    McGuinness, C.L.

    1951-01-01

    This report was prepared in July 1950 at the request of the President's Water Resources Policy Commission. It followed the report entitled Water facts in relation to a national water-resources policy," which, in part, has been published as Geological Survey Circular 114 under the title "The water situation in the United States, with special reference to ground water.''

  17. RESEARCH TO SUPPORT RESTORATION OF GROUND WATER CONTAMINATED WITH ARSENIC

    Science.gov (United States)

    A brief programmatic overview will be presented to highlight research and technical support efforts underway at the Ground Water and Ecosystems Restoration Division in Ada, Oklahoma. Details from a case study will be presented to emphasize the technical challenges encountered du...

  18. Ground water arsenic contamination: A local survey in India

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2016-01-01

    Conclusions: The present study concludes that in Simri village there is high contamination of arsenic in ground water in all the strips. Such a huge population is at very high risk leading the village on the verge of causing health hazards among them. Therefore, an immediate strategy is required to combat the present problem.

  19. Ground Water Arsenic Contamination: A Local Survey in India.

    Science.gov (United States)

    Kumar, Arun; Rahman, Md Samiur; Iqubal, Md Asif; Ali, Mohammad; Niraj, Pintoo Kumar; Anand, Gautam; Kumar, Prabhat; Abhinav; Ghosh, Ashok Kumar

    2016-01-01

    In the present times, arsenic poisoning contamination in the ground water has caused lots of health-related problems in the village population residing in middle Gangetic plain. In Bihar, about 16 districts have been reported to be affected with arsenic poisoning. For the ground water and health assessment, Simri village of Buxar district was undertaken which is a flood plain region of river Ganga. In this study, 322 water samples were collected for arsenic estimation, and their results were analyzed. Furthermore, the correlation between arsenic contamination in ground water with depth and its distance from river Ganga were analyzed. Results are presented as mean ± standard deviation and total variation present in a set of data was analyzed through one-way analysis of variance. The difference among mean values has been analyzed by applying Dunnett's test. The criterion for statistical significance was set at P arsenic concentration in hand pumps. Furthermore, a correlation between the arsenic concentration with the depth of the hand pumps and the distance from the river Ganga was also a significant study. The present study concludes that in Simri village there is high contamination of arsenic in ground water in all the strips. Such a huge population is at very high risk leading the village on the verge of causing health hazards among them. Therefore, an immediate strategy is required to combat the present problem.

  20. Ground-water resources in the vicinity of Cortland, Trumbull County, Ohio

    Science.gov (United States)

    Barton, G.J.; Wright, P.R.

    1997-01-01

    Mosquito Creek Lake shoreline and the Bazetta-Fowler Township line-approximately 15,000 million gallons of water currently in the Cussewago Sandstone can be gravity drained from the aquifer without considering recharge to the aquifer. The 15,000 million gallons is equivalent to about 75 years of withdrawals by Cortland public-supply wells at current (1990-95) rates. A numerical flow model rather than an analytical or semianalytical model would be needed to accurately simulate flow and ground-water withdrawals in the Cussewago Sandstone in the vicinity of Cortland. Computer simulations of flow would likely involve conditions where a fully saturated, confined Cussewago Sandstone becomes a partially saturated aquifer.

  1. Hydrogeology, ground-water use, and ground-water levels in the Mill Creek Valley near Evendale, Ohio

    Science.gov (United States)

    Schalk, Charles; Schumann, Thomas

    2002-01-01

    Withdrawals of ground water in the central Mill Creek Valley near Evendale, Ohio, caused water-level declines of more than 100 feet by the 1950s. Since the 1950s, management practices have changed to reduce the withdrawals of ground water, and recovery of water levels in long-term monitoring wells in the valley has been documented. Changing conditions such as these prompted a survey of water use, streamflow conditions, and water levels in several aquifers in the central Mill Creek Valley, Hamilton and Butler Counties, Ohio. Geohydrologic information, water use, and water levels were compiled from historical records and collected during the regional survey. Data collected during the survey are presented in terms of updated geohydrologic information, water use in the study area, water levels in the aquifers, and interactions between ground water and surface water. Some of the data are concentrated at former Air Force Plant 36 (AFP36), which is collocated with the General Electric Aircraft Engines (GEAE) plant, and these data are used to describe geohydrology and water levels on a more local scale at and near the plant. A comparison of past and current ground-water use and levels indicates that the demand for ground water is decreasing and water levels are rising. Before 1955, most of the major industrial ground-water users had their own wells, ground water was mined from a confined surficial (lower) aquifer, and water levels were more than 100 feet below their predevelopment level. Since 1955, however, these users have been purchasing their water from the city of Cincinnati or a private water purveyor. The cities of Reading and Lockland, both producers of municipal ground-water supplies in the area, shut down their well fields within their city limits. Because the demand for ground-water supplies in the valley has lessened greatly since the 1950s, withdrawals have decreased, and, consequently, water levels in the lower aquifer are 65 to 105 feet higher than they were

  2. Mathematical modeling of kidney transport.

    Science.gov (United States)

    Layton, Anita T

    2013-01-01

    In addition to metabolic waste and toxin excretion, the kidney also plays an indispensable role in regulating the balance of water, electrolytes, nitrogen, and acid-base. In this review, we describe representative mathematical models that have been developed to better understand kidney physiology and pathophysiology, including the regulation of glomerular filtration, the regulation of renal blood flow by means of the tubuloglomerular feedback mechanisms and of the myogenic mechanism, the urine concentrating mechanism, epithelial transport, and regulation of renal oxygen transport. We discuss the extent to which these modeling efforts have expanded our understanding of renal function in both health and disease.

  3. Use of environmental tracers to evaluate ground-water age and water-quality trends in a buried-valley aquifer, Dayton area, southwestern, Ohio

    Science.gov (United States)

    Rowe, Gary L.; Shapiro, Stephanie Dunkle; Schlosser, Peter

    1999-01-01

    Chlorofluorocarbons (CFC method) and tritium and helium isotopes (3H-3He method) were used as environmental tracers to estimate ground-water age in conjunction with efforts to develop a regional ground-water flow model of the buried-valley aquifer in the Dayton area, southwestern Ohio. This report describes results of CFC and water-quality sampling, summarizes relevant aspects of previously published work, and describes the use of 3H-3He ages to characterize temporal trends in ground-water quality of the buried-valley aquifer near Dayton, Ohio. Results of CFC sampling indicate that approximately 25 percent of the 137 sampled wells were contaminated with excess CFC's that rendered the ground water unsuitable for age dating. Evaluation of CFC ages obtained for the remaining samples indicated that the CFC compounds used for dating were being affected by microbial degradation. The degradation occurred under anoxic conditions that are found in most parts of the buried-valley aquifer. As a result, ground-water ages derived by the CFC method were too old and were inconsistent with measured tritium concentrations and independently derived 3H-3He ages. Limited data indicate that dissolved methane may play an important role in the degradation of the CFC's. In contrast, the 3H-3He technique was found to yield ground-water ages that were chemically and hydrologically reasonable. Ground-water ages derived by the 3H-3He technique were compared to values for selected water- quality characteristics to evaluate temporal trends in ground-water quality in the buried- valley aquifer. Distinct temporal trends were not identified for pH, alkalinity, or calcium and magnesium because of rapid equilibration of ground-water with calcite and dolomite in aquifer sediments. Temporal trends in which the amount of scatter and the number of outlier concentrations increased as ground-water age decreased were noted for sodium, potassium, boron, bromide, chloride, ammonia, nitrate, phosphate

  4. Ground-water conditions in the Dutch Flats area, Scotts Bluff and Sioux Counties, Nebraska, with a section on chemical quality of the ground water

    Science.gov (United States)

    Babcock, H.M.; Visher, F.N.; Durum, W.H.

    1951-01-01

    The U.S. Department of the Interior (DOI) studied contamination induced by irrigation drainage in 26 areas of the Western United States during 1986-95. Comprehensive compilation, synthesis, and evaluation of the data resulting from these studies were initiated by DOI in 1992. Soils and ground water in irrigated areas of the West can contain high concentrations of selenium because of (1) residual selenium from the soil's parent rock beneath irrigated land; (2) selenium derived from rocks in mountains upland from irrigated land by erosion and transport along local drainages, and (3) selenium brought into the area in surface water imported for irrigation. Application of irrigation water to seleniferous soils can dissolve and mobilize selenium and create hydraulic gradients that cause the discharge of seleniferous ground water into irrigation drains. Given a source of selenium, the magnitude of selenium contamination in drainage-affected aquatic ecosystems is strongly related to the aridity of the area and the presence of terminal lakes and ponds. Marine sedimentary rocks and deposits of Late Cretaceous or Tertiary age are generally seleniferous in the Western United States. Depending on their origin and history, some Tertiary continental sedimentary deposits also are seleniferous. Irrigation of areas associated with these rocks and deposits can result in concentrations of selenium in water that exceed criteria for the protection of freshwater aquatic life. Geologic and climatic data for the Western United States were evaluated and incorporated into a geographic information system (GIS) to produce a map identifying areas susceptible to irrigation-induced selenium contamination. Land is considered susceptible where a geologic source of selenium is in or near the area and where the evaporation rate is more than 2.5 times the precipitation rate. In the Western United States, about 160,000 square miles of land, which includes about 4,100 square miles (2.6 million acres) of

  5. Radionuclides in ground water of the Carson River Basin, western Nevada and eastern California, U.S.A.

    Science.gov (United States)

    Thomas, J.M.; Welch, A.H.; Lico, M.S.; Hughes, J.L.; Whitney, R.

    1993-01-01

    Ground water is the main source of domestic and public supply in the Carson River Basin. Ground water originates as precipitation primarily in the Sierra Nevada in the western part of Carson and Eagle Valleys, and flows down gradient in the direction of the Carson River through Dayton and Churchill Valleys to a terminal sink in the Carson Desert. Because radionuclides dissolved in ground water can pose a threat to human health, the distribution and sources of several naturally occurring radionuclides that contribute to gross-alpha and gross-beta activities in the study area were investigated. Generally, alpha and beta activities and U concentration increase from the up-gradient to down-gradient hydrographic areas of the Carson River Basin, whereas 222Rn concentration decreases. Both 226Ra and 228Ra concentrations are similar throughout the study area. Alpha and beta activities and U concentration commonly exceed 100 pCi/l in the Carson Desert at the distal end of the flow system. Radon-222 commonly exceeds 2,000 pCi/l in the western part of Carson and Eagle Valleys adjacent to the Sierra Nevada. Radium-226 and 228Ra concentrations are oxide coatings on fracture surfaces and fine-grained sediment, by adsorption on organic matter, and by coprecipitation with Fe and Mn oxides. These coated sediments are transported throughout the basin by fluvial processes. Thus, U is transported as dissolved and adsorbed species. A rise in the water table in the Carson Desert because of irrigation has resulted in the oxidation of U-rich organic matter and dissolution of U-bearing coatings on sediments, producing unusually high U concentration in the ground water. Alpha activity in the ground water is almost entirely from the decay of U dissolved in the water. Beta activity in ground water samples is primarily from the decay of 40K dissolved in the water and ingrowth of 238U progeny in the sample before analysis. Approximately one-half of the measured beta activity may not be present

  6. Ground-water temperature of the Wyoming quadrangle in central Delaware : with application to ground-water-source heat pumps

    Science.gov (United States)

    Hodges, Arthur L.

    1982-01-01

    Ground-water temperature was measured during a one-year period (1980-81) in 20 wells in the Wyoming Quadrangle in central Delaware. Data from thermistors set at fixed depths in two wells were collected twice each week, and vertical temperature profiles of the remaining 18 wells were made monthly. Ground-water temperature at 8 feet below land surface in well Jc55-1 ranged from 45.0 degrees F in February to 70.1 degrees F in September. Temperature at 35 feet below land surface in the same well reached a minimum of 56.0 degrees F in August, and a maximum of 57.8 degrees F in February. Average annual temperature of ground water at 25 feet below land surface in all wells ranged from 54.6 degrees F to 57.8 degrees F. Variations of average temperature probably reflect the presence or absence of forestation in the recharge areas of the wells. Ground-water-source heat pumps supplied with water from wells 30 or more feet below land surface will operate more efficiently in both heating and cooling modes than those supplied with water from shallower depths. (USGS)

  7. Hydrogeologic setting, ground-water flow, and ground-water quality at the Lake Wheeler Road research station, 2001-03 : North Carolina Piedmont and Mountains Resource Evaluation Program

    Science.gov (United States)

    Chapman, Melinda J.; Bolich, Richard E.; Huffman, Brad A.

    2005-01-01

    Results of a 2-year field study of the regolith-fractured bedrock ground-water system at the Lake Wheeler Road research station in Wake County, North Carolina, indicate both disconnection and interaction among components of the ground-water system. The three components of the ground-water system include (1) shallow, porous regolith; (2) a transition zone, including partially weathered rock, having both secondary (fractures) and primary porosity; and (3) deeper, fractured bedrock that has little, if any, primary porosity and is dominated by secondary fractures. The research station includes 15 wells (including a well transect from topographic high to low settings) completed in the three major components of the ground-water-flow system and a surface-water gaging station on an unnamed tributary. The Lake Wheeler Road research station is considered representative of a felsic gneiss hydrogeologic unit having steeply dipping foliation and a relatively thick overlying regolith. Bedrock foliation generally strikes N. 10? E. to N. 30? E. and N. 20? W. to N. 40? W. to a depth of about 400 feet and dips between 70? and 80? SE. and NE., respectively. From 400 to 600 feet, the foliation generally strikes N. 70? E. to N. 80? E., dipping 70? to 80? SE. Depth to bedrock locally ranges from about 67 to 77 feet below land surface. Fractures in the bedrock generally occur in two primary sets: low dip angle, stress relief fractures that cross cut foliation, and steeply dipping fractures parallel to foliation. Findings of this study generally support the conceptual models of ground-water flow from high to low topographic settings developed for the Piedmont and Blue Ridge Provinces in previous investigations, but are considered a refinement of the generalized conceptual model based on a detailed local-scale investigation. Ground water flows toward a surface-water boundary, and hydraulic gradients generally are downward in recharge areas and upward in discharge areas; however, local

  8. Potential ground water resources of Hat Yai Basin in Peninsular Thailand by gravity study

    Directory of Open Access Journals (Sweden)

    Warawutti Lohawijarn

    2005-05-01

    Full Text Available Residual gravity anomaly with a minimum of about -140 mm s-2 with approximately NS trend and a limited axial length was observed over Hat Yai Basin in Peninsular Thailand. The modeled Hat Yai basin is about 1 km deep at its deepest, 60 km long and 20 km wide. The porosity of basin sediment and the amount of potential ground water reserves within the basin are estimated to be 39% and 121.7±0.8 km3 respectively, assuming full saturation. Within the topmost 80 m of ground where the present extraction is concentrated, the estimated ground water reserve is 12.5±0.5 km3.

  9. Industrial Waste Management Evaluation Model Version 3.1

    Science.gov (United States)

    IWEM is a screening level ground water model designed to simulate contaminant fate and transport. IWEM v3.1 is the latest version of the IWEM software, which includes additional tools to evaluate the beneficial use of industrial materials

  10. Precipitation; ground-water age; ground-water nitrate concentrations, 1995-2002; and ground-water levels, 2002-03 in Eastern Bernalillo County, New Mexico

    Science.gov (United States)

    Blanchard, Paul J.

    2004-01-01

    The eastern Bernalillo County study area consists of about 150 square miles and includes all of Bernalillo County east of the crests of the Sandia and Manzanita Mountains. Soil and unconsolidated alluvial deposits overlie fractured and solution-channeled limestone in most of the study area. North of Interstate Highway 40 and east of New Mexico Highway 14, the uppermost consolidated geologic units are fractured sandstones and shales. Average annual precipitation at three long-term National Oceanic and Atmospheric Administration precipitation and snowfall data-collection sites was 14.94 inches at approximately 6,300 feet (Sandia Ranger Station), 19.06 inches at about 7,020 feet (Sandia Park), and 23.07 inches at approximately 10,680 feet (Sandia Crest). The periods of record at these sites are 1933-74, 1939-2001, and 1953-79, respectively. Average annual snowfall during these same periods of record was 27.7 inches at Sandia Ranger Station, 60.8 inches at Sandia Park, and 115.5 inches at Sandia Crest. Seven precipitation data-collection sites were established during December 2000-March 2001. Precipitation during 2001-03 at three U.S. Geological Survey sites ranged from 66 to 94 percent of period-of-record average annual precipitation at corresponding National Oceanic and Atmospheric Administration long-term sites in 2001, from 51 to 75 percent in 2002, and from 34 to 81 percent during January through September 2003. Missing precipitation records for one site resulted in the 34-percent value in 2003. Analyses of concentrations of chlorofluorocarbons CFC-11, CFC-12, and CFC-113 in ground-water samples from nine wells and one spring were used to estimate when the sampled water entered the ground-water system. Apparent ages of ground water ranged from as young as about 10 to 16 years to as old as about 20 to 26 years. Concentrations of dissolved nitrates in samples collected from 24 wells during 2001-02 were similar to concentrations in samples collected from the same

  11. Ground-water conditions and studies in Georgia, 2001

    Science.gov (United States)

    Leeth, David C.; Clarke, John S.; Craigg, Steven D.; Wipperfurth, Caryl J.

    2003-01-01

    The U.S. Geological Survey (USGS) collects ground-water data and conducts studies to monitor hydrologic conditions, to better define ground-water resources, and address problems related to water supply and water quality. Data collected as part of ground-water studies include geologic, geophysical, hydraulic property, water level, and water quality. A ground-water-level network has been established throughout most of the State of Georgia, and ground-water-quality networks have been established in the cities of Albany, Savannah, and Brunswick and in Camden County, Georgia. Ground-water levels are monitored continuously in a network of wells completed in major aquifers of the State. This network includes 17 wells in the surficial aquifer, 12 wells in the upper and lower Brunswick aquifers, 73 wells in the Upper Floridan aquifer, 10 wells in the Lower Floridan aquifer and underlying units, 12 wells in the Claiborne aquifer, 1 well in the Gordon aquifer, 11 wells in the Clayton aquifer, 11 wells in the Cretaceous aquifer system, 2 wells in Paleozoic-rock aquifers, and 7 wells in crystalline-rock aquifers. In this report, data from these 156 wells were evaluated to determine whether mean-annual ground-water levels were within, below, or above the normal range during 2001, based on summary statistics for the period of record. Information from these summaries indicates that water levels during 2001 were below normal in almost all aquifers monitored, largely reflecting climatic effects from drought and pumping. In addition, water-level hydrographs for selected wells indicate that water levels have declined during the past 5 years (since 1997) in almost all aquifers monitored, with water levels in some wells falling below historical lows. In addition to continuous water-level data, periodic measurements taken in 52 wells in the Camden County-Charlton County area, and 65 wells in the city of Albany-Dougherty County area were used to construct potentiometric-surface maps for

  12. Simulation of ground-water flow in the Albuquerque Basin, central New Mexico, 1901-95, with projections to 2020

    Science.gov (United States)

    Kernodle, J.M.

    1998-01-01

    The ground-water-flow model of the Albuquerque Basin (Kernodle, J.M., McAda, D.P., and Thorn, C.R., 1995, Simulation of ground-water flow in the Albuquerque Basin, central New Mexico, with projections to 2020: U.S. Geological Survey Water-Resources Investigations Report 94-4251, 114 p.) was updated to include new information on the hydrogeologic framework (Hawley, J.W., Haase, C.S., and Lozinsky, R.P., 1995, An underground view of the Albuquerque Basin: Proceedings of the 39th Annual New Mexico Water Conference, November 3-4, 1994, p. 37-55). An additional year of ground-water-withdrawal data was appended to the simulation of the historical period and incorporated into the base for future projections to the year 2020. The revised model projects the simulated ground-water levels associated with an aerally enlarged occurrence of the relatively high hydraulic conductivity in the upper part of the Santa Fe Group east and west of the Rio Grande in the Albuquerque area and north to Bernalillo. Although the differences between the two model versions are substantial, the revised model does not contradict any previous conclusions about the effect of City of Albuquerque ground-water withdrawals on flow in the Rio Grande or the net benefits of an effort to conserve ground water. Recent revisions to the hydrogeologic model (Hawley, J.W., Haneberg, W.C., and Whitworth, P.M., in press, Hydrogeologic investigations in the Albuquerque Basin, central New Mexico, 1992-1995: Socorro, New Mexico Bureau of Mines and Mineral Resources Open- File Report 402) of the Albuquerque Basin eventually will require that this model version also be revised and updated.

  13. Aquifer-scale controls on the distribution of nitrate and ammonium in ground water near La Pine, Oregon, USA

    Science.gov (United States)

    Hinkle, Stephen R.; Böhlke, J. K.; Duff, John H.; Morgan, David S.; Weick, Rodney J.

    2007-02-01

    SummaryGeochemical and isotopic tools were applied at aquifer, transect, and subtransect scales to provide a framework for understanding sources, transport, and fate of dissolved inorganic N in a sandy aquifer near La Pine, Oregon. NO 3 is a common contaminant in shallow ground water in this area, whereas high concentrations of NH 4-N (up to 39 mg/L) are present in deep ground water. N concentrations, N/Cl ratios, tracer-based apparent ground-water ages, N isotope data, and hydraulic gradients indicate that septic tank effluent is the primary source of NO 3. N isotope data, N/Cl and N/C relations, 3H data, and hydraulic considerations point to a natural, sedimentary organic matter source for the high concentrations of NH 4, and are inconsistent with an origin as septic tank N. Low recharge rates and flow velocities have largely restricted anthropogenic NO 3 to isolated plumes within several meters of the water table. A variety of geochemical and isotopic data indicate that denitrification also affects NO 3 gradients in the aquifer. Ground water in the La Pine aquifer evolves from oxic to increasingly reduced conditions. Suboxic conditions are achieved after about 15-30 y of transport below the water table. NO 3 is denitrified near the oxic/suboxic boundary. Denitrification in the La Pine aquifer is characterized well at the aquifer scale with a redox boundary approach that inherently captures spatial variability in the distribution of electron donors.

  14. Ground-Water Recharge in Humid Areas of the United States--A Summary of Ground-Water Resources Program Studies, 2003-2006

    Science.gov (United States)

    Delin, Geoffrey N.; Risser, Dennis W.

    2007-01-01

    Increased demands on water resources by a growing population and recent droughts have raised awareness about the adequacy of ground-water resources in humid areas of the United States. The spatial and temporal variability of ground-water recharge are key factors that need to be quantified to determine the sustainability of ground-water resources. Ground-water recharge is defined herein as the entry into the saturated zone of water made available at the water-table surface, together with the associated flow away from the water table within the saturated zone (Freeze and Cherry, 1979). In response to the need for better estimates of ground-water recharge, the Ground-Water Resources Program (GWRP) of the U.S. Geological Survey (USGS) began an initiative in 2003 to estimate ground-water recharge rates in the relatively humid areas of the United States.

  15. Simulation of Ground-Water Flow in the Irwin Basin Aquifer System, Fort Irwin National Training Center, California

    Science.gov (United States)

    Densmore, Jill N.

    2003-01-01

    Ground-water pumping in the Irwin Basin at Fort Irwin National Training Center, California resulted in water-level declines of about 30 feet from 1941 to 1996. Since 1992, artificial recharge from wastewater-effluent infiltration and irrigation-return flow has stabilized water levels, but there is concern that future water demands associated with expansion of the base may cause a resumption of water-level declines. To address these concerns, a ground-water flow model of the Irwin Basin was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Historical data show that ground-water-level declines in the Irwin Basin between 1941 and 1996, caused the formation of a pumping depression near the pumped wells, and that recharge from the wastewater-treatment facility and disposal area caused the formation of a recharge mound. There have been two periods of water-level recovery in the Irwin Basin since the development of ground water in this basin; these periods coincide with a period of decreased pumpage from the basin and a period of increased recharge of water imported from the Bicycle Basin beginning in 1967 and from the Langford Basin beginning in 1992. Since 1992, artificial recharge has exceeded pumpage in the Irwin Basin and has stabilized water-level declines. A two-layer ground-water flow model was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Boundary conditions, hydraulic conductivity, altitude of the bottom of the layers, vertical conductance, storage coefficient, recharge, and discharge were determined using existing geohydrologic data. Rates and distribution of recharge and discharge were determined from

  16. Ground-water quality and geochemistry in Dayton, Stagecoach, and Churchill Valleys, western Nevada

    Science.gov (United States)

    Thomas, James M.; Lawrence, Stephen J.

    1994-01-01

    The U.S. Geological Survey investigated the quality of ground water in the Dayton, Stagecoach, and Churchill Valleys as part of the Carson River Basin National Water-Quality Assessment (NAWQA) pilot study. Four aquifer systems have been de- lineated in the study area. Principal aquifers are unconsolidated deposits at altitudes of less than 4,900 feet above sea level and more than 50 feet below land surface. Shallow aquifers are at altitudes of less than 4,900 feet and less than 50 feet below land surface. Upland aquifers are above 4,900 feet and provide recharge to the principal aquifers. Thermal aquifers, defined as those having a water temperature greater than 30 degrees Celsius, are also present. Ground water used in Dayton, Stagecoach, and Churchill Valleys is pumped from principal aquifers in unconsolidated basin-fill deposits. Ground water in these aquifers originates as precipitation in the adjacent mountains and is recharged by the Carson River and by underflow from adjacent upstream valleys. Ground-water flow is generally parallel to the direction of surface-water flow in the Carson River. Ground water is discharged by pumping, evapo- transpiration, and underflow into the Carson River. The results of geochemical modeling indicate that as ground water moves from upland aquifers in mountainous recharge areas to principal aquifers in basin-fill deposits, the following processes probably occur: (1) plagioclase feldspar, sodium chloride, gypsum (or pyrite), potassium feldspar, and biotite dissolve; (2) calcite precipitates; (3) kaolinite forms; (4) small amounts of calcium and magnesium in the water exchange for potassium on aquifer minerals; and (5) carbon dioxide is gained or lost. The geochemical models are consistent with (1) phases identified in basin- fill sediments; (2) chemical activity of major cations and silica; (3) saturation indices of calcite and amorphous silica; (4) phase relations for aluminosilicate minerals indicated by activity diagrams; and

  17. PRO-GRADE: GIS toolkits for ground water recharge and discharge estimation.

    Science.gov (United States)

    Lin, Yu-Feng; Wang, Jihua; Valocchi, Albert J

    2009-01-01

    PRO-GRADE is an ESRI ArcGIS 9.2 plug-in package that consists of two separate toolkits: (1) the pattern recognition organizer for geographic information system (PRO-GIS) and (2) the ground water recharge and discharge estimator for GIS (GRADE-GIS). PRO-GIS is a collection of several existing image-processing algorithms into one user interface to offer the flexibility to extract spatial patterns according to the user's needs. GRADE-GIS is a ground water recharge and discharge estimation interface using a mass balance method that requires only hydraulic conductivity, water table, and bedrock elevation data for simulating two-dimensional steady-state unconfined aquifers. PRO-GRADE was developed to assist ongoing assessments of the water resources in Illinois and Wisconsin, and is being used to assist several ground water resource studies in several locations in the United States. The advantage of using PRO-GRADE is to enable fast production of initial recharge and discharge maps that can be further enhanced by using a follow-up ground water flow model with parameter estimation codes. PRO-GRADE leverages ArcGIS to provide a computer-assisted framework to support expert judgment in order to efficiently select alternative recharge and discharge maps that can be used as (1) guidelines for field study planning and decision making; (2) initial conditions for numerical simulation; and (3) screening for alternative model selection and prediction/parameter uncertainty evaluation. In addition, PRO-GRADE allows for more easy and rapid correlation of those maps with other hydrologically relevant geospatial data.

  18. Documentation of the Surface-Water Routing (SWR1) Process for modeling surface-water flow with the U.S. Geological Survey Modular Ground-Water Model (MODFLOW-2005)

    Science.gov (United States)

    Hughes, Joseph D.; Langevin, Christian D.; Chartier, Kevin L.; White, Jeremy T.

    2012-01-01

    A flexible Surface-Water Routing (SWR1) Process that solves the continuity equation for one-dimensional and two-dimensional surface-water flow routing has been developed for the U.S. Geological Survey three-dimensional groundwater model, MODFLOW-2005. Simple level- and tilted-pool reservoir routing and a diffusive-wave approximation of the Saint-Venant equations have been implemented. Both methods can be implemented in the same model and the solution method can be simplified to represent constant-stage elements that are functionally equivalent to the standard MODFLOW River or Drain Package boundary conditions. A generic approach has been used to represent surface-water features (reaches) and allows implementation of a variety of geometric forms. One-dimensional geometric forms include rectangular, trapezoidal, and irregular cross section reaches to simulate one-dimensional surface-water features, such as canals and streams. Two-dimensional geometric forms include reaches defined using specified stage-volume-area-perimeter (SVAP) tables and reaches covering entire finite-difference grid cells to simulate two-dimensional surface-water features, such as wetlands and lakes. Specified SVAP tables can be used to represent reaches that are smaller than the finite-difference grid cell (for example, isolated lakes), or reaches that cannot be represented accurately using the defined top of the model. Specified lateral flows (which can represent point and distributed flows) and stage-dependent rainfall and evaporation can be applied to each reach. The SWR1 Process can be used with the MODFLOW Unsaturated Zone Flow (UZF1) Package to permit dynamic simulation of runoff from the land surface to specified reaches. Surface-water/groundwater interactions in the SWR1 Process are mathematically defined to be a function of the difference between simulated stages and groundwater levels, and the specific form of the reach conductance equation used in each reach. Conductance can be

  19. Ground-water resources in the Hood Basin, Oregon

    Science.gov (United States)

    Grady, Stephen J.

    1983-01-01

    The Hood Basin, an area of 1,035 square miles in north-central Oregon, includes the drainage basins of all tributaries of the Columbia River between Eagle Creek and Fifteenmile Creek. The physical characteristics and climate of the basin are diverse. The Wasco subarea, in the eastern half of the basin, has moderate relief, mostly intermittent streams, and semiarid climate. The Hood subarea, in the western half, has rugged topography, numerous perennial streams, and a humid climate.Water-bearing geologic units that underlie the basin include volcanic, volcaniclastic, and sedimentary rocks of Miocene to Holocene age, and unconsolidated surficial deposits of Pleistocene and Holocene age. The most important water-bearing unit, the Columbia River Basalt Group, underlies almost the entire basin. Total thickness probably exceeds 2,000 feet, but by 1980 only the upper 1,000 feet or less had been developed by wells. Wells in this unit generally yield from 15 to 1,000 gallons per minute and a few yield as much as 3,300 gallons per minute.The most productive aquifer in the Columbia River Basalt Group is The Dalles Ground Water Reservoir, a permeable zone of fractured basalt about 25 to 30 square miles in extent that underlies the city of The Dalles. During the late 1950's and mid-1960's, withdrawals of 15,000 acre-feet per year or more caused water levels in the aquifer to decline sharply. Pumpage had diminished to about 5,000 acre-feet per year in 1979 and water levels have stabilized, indicating that ground water recharge and discharge, including the pumping, are in balance.The other principal geologic units in the basin have more limited areal distribution and less saturated thickness than the Columbia River Basalt Group. Generally, these units are capable of yielding from a few to a hundred gallons per minute to wells.Most of the ground water in the basin is chemically suitable for domestic, irrigation, or other uses. Some ground water has objectionable concentrations of

  20. Ground Water Atlas of the United States: Segment 1, California, Nevada

    Science.gov (United States)

    Planert, Michael; Williams, John S.

    1995-01-01

    California and Nevada compose Segment 1 of the Ground Water Atlas of the United States. Segment 1 is a region of pronounced physiographic and climatic contrasts. From the Cascade Mountains and the Sierra Nevada of northern California, where precipitation is abundant, to the Great Basin in Nevada and the deserts of southern California, which have the most arid environments in the United States, few regions exhibit such a diversity of topography or environment. Since the discovery of gold in the mid-1800's, California has experienced a population, industrial, and agricultural boom unrivaled by that of any other State. Water needs in California are very large, and the State leads the United States in agricultural and municipal water use. The demand for water exceeds the natural water supply in many agricultural and nearly all urban areas. As a result, water is impounded by reservoirs in areas of surplus and transported to areas of scarcity by an extensive network of aqueducts. Unlike California, which has a relative abundance of water, development in Nevada has been limited by a scarcity of recoverable freshwater. The Truckee, the Carson, the Walker, the Humboldt, and the Colorado Rivers are the only perennial streams of significance in the State. The individual basin-fill aquifers, which together compose the largest known ground-water reserves, receive little annual recharge and are easily depleted. Nevada is sparsely populated, except for the Las Vegas, the Reno-Sparks, and the Carson City areas, which rely heavily on imported water for public supplies. Although important to the economy of Nevada, agriculture has not been developed to the same degree as in California due, in large part, to a scarcity of water. Some additional ground-water development might be possible in Nevada through prudent management of the basin-fill aquifers and increased utilization of ground water in the little-developed carbonate-rock aquifers that underlie the eastern one-half of the State

  1. Modelling of Transport Projects Uncertainties

    DEFF Research Database (Denmark)

    Salling, Kim Bang; Leleur, Steen

    2012-01-01

    This paper proposes a new way of handling the uncertainties present in transport decision making based on infrastructure appraisals. The paper suggests to combine the principle of Optimism Bias, which depicts the historical tendency of overestimating transport related benefits and underestimating...... investment costs, with a quantitative risk analysis based on Monte Carlo simulation and to make use of a set of exploratory scenarios. The analysis is carried out by using the CBA-DK model representing the Danish standard approach to socio-economic cost-benefit analysis. Specifically, the paper proposes......-based graphs which functions as risk-related decision support for the appraised transport infrastructure project. The presentation of RSF is demonstrated by using an appraisal case concerning a new airfield in the capital of Greenland, Nuuk....

  2. Estimates of ground-water discharge as determined from measurements of evapotranspiration, Ash Meadows area, Nye County, Nevada

    Science.gov (United States)

    Laczniak, R.J.; DeMeo, G.A.; Reiner, S.R.; Smith, Jody L.; Nylund, W.E.

    1999-01-01

    Ash Meadows is one of the major discharge areas within the regional Death Valley ground-water flow system of southern Nevada and adjacent California. Ground water discharging at Ash Meadows is replenished from inflow derived from an extensive recharge area that includes the eastern part of the Nevada Test Site (NTS). Currently, contaminants introduced into the subsurface by past nuclear testing at NTS are the subject of study by the U.S. Department of Energy's Environmental Restoration Program. The transport of any contaminant in contact with ground water is controlled in part by the rate and direction of ground-water flow, which itself depends on the location and quantity of ground water discharging from the flow system. To best evaluate any potential risk associated with these test-generated contaminants, studies were undertaken to accurately quantify discharge from areas downgradient from the NTS. This report presents results of a study to refine the estimate of ground-water discharge at Ash Meadows. The study estimates ground-water discharge from the Ash Meadows area through a rigorous quantification of evapotranspiration (ET). To accomplish this objective, the study identifies areas of ongoing ground-water ET, delineates unique areas of ET defined on the basis of similarities in vegetation and soil-moisture conditions, and computes ET rates for each of the delineated areas. A classification technique using spectral-reflectance characteristics determined from satellite images recorded in 1992 identified seven unique units representing areas of ground-water ET. The total area classified encompasses about 10,350 acres dominated primarily by lush desert vegetation. Each unique area, referred to as an ET unit, generally consists of one or more assemblages of local phreatophytes. The ET units identified range from sparse grasslands to open water. Annual ET rates are computed by energy-budget methods from micrometeorological measurements made at 10 sites within six

  3. Assessment of Ground Water Quality in Rajajinagar of Bangalore

    Directory of Open Access Journals (Sweden)

    Alimuddin

    2015-04-01

    Full Text Available Water borne diseases continue to be a dominant cause of water borne morbidities and mortality all over the world. Hence, drinking water needs to be protected from pollution and biological contamination. Ground water samples were collected from ten different sampling point in Rajajinagar area of Bangalore and analysed for water quality parameters viz. pH , total alkalinity, chloride, total dissolved solids, electrical conductivity, sodium, potassium, calcium, magnesium, dissolved oxygen, BOD, COD and total hardness. The pH value of the study area ranges between 7.3 to 8.4 indicating that ground water is slightly alkaline. The total alkalinity are varied in the range from 122 to 282 mg/l which is well within the limit prescribed by BIS. The TDS value found from 397 to 546 mg/l. The values of hardness of water ranges from 125 to 267 mg/l which is within the prescribed limit as per BIS.

  4. Vulnerability of ground water to contamination, northern Bexar County, Texas

    Science.gov (United States)

    Clark, Amy R.

    2003-01-01

    The Trinity aquifer, composed of Lower Cretaceous carbonate rocks, largely controls the ground-water hydrology in the study area of northern Bexar County, Texas. Discharge from the Trinity aquifer recharges the downgradient, hydraulically connected Edwards aquifer one of the most permeable and productive aquifers in the Nation and the sole source of water for more than a million people in south-central Texas. The unconfined, karstic outcrop of the Edwards aquifer makes it particularly vulnerable to contamination resulting from urbanization that is spreading rapidly northward across an "environmentally sensitive" recharge zone of the Edwards aquifer and its upgradient "catchment area," composed mostly of the less permeable Trinity aquifer.A better understanding of the Trinity aquifer is needed to evaluate water-management decisions affecting the quality of water in both the Trinity and Edwards aquifers. A study was made, therefore, in cooperation with the San Antonio Water System to assess northern Bexar County's vulnerability to ground-water contamination. The vulnerability of ground water to contamination in this area varies with the effects of five categories of natural features (hydrogeologic units, faults, caves and (or) sinkholes, slopes, and soils) that occur on the outcrop and in the shallow subcrop of the Glen Rose Limestone.Where faults affect the rates of recharge or discharge or the patterns of ground-water flow in the Glen Rose Limestone, they likewise affect the risk of water-quality degradation. Caves and sinkholes generally increase the vulnerability of ground water to contamination, especially where their occurrences are concentrated. The slope of land surface can affect the vulnerability of ground water by controlling where and how long a potential contaminant remains on the surface. Disregarding the exception of steep slopes which are assumed to have no soil cover the greater the slope, the less the risk of ground-water contamination. Because most

  5. Ground-Water Conditions and Studies in the Brunswick-Glynn County Area, Georgia, 2007

    Science.gov (United States)

    Cherry, Gregory S.; Clarke, John S.

    2008-01-01

    The Upper Floridan aquifer is contaminated with saltwater in a 2-square-mile area of downtown Brunswick, Georgia. This contamination has limited the development of the ground-water supply in the Glynn County area. Hydrologic, geologic, and water-quality data are needed to effectively manage water resources. Since 1959, the U.S. Geological Survey has conducted a cooperative water-resources program with the City of Brunswick to monitor and assess the effect of ground-water development on saltwater contamination of the Floridan aquifer system. The potential development of alternative sources of water in the Brunswick and surficial aquifer systems also is an important consideration in coastal areas. During calendar year 2007, the cooperative water-resources monitoring program included continuous water-level recording of 13 wells completed in the Floridan, Brunswick, and surficial aquifer systems; collecting water levels from 22 wells to map the potentiometric surface of the Upper Floridan aquifer during July and August 2007; and collecting and analyzing water samples from 76 wells to map chloride concentrations in the Upper Floridan aquifer during July and August 2007. In addition, work was initiated to refine an existing ground-water flow model for evaluation of water-management scenarios.

  6. Ground-water resources of coastal Citrus, Hernando, and southwestern Levy counties, Florida

    Science.gov (United States)

    Fretwell, J.D.

    1983-01-01

    Ground water in the coastal parts of Citrus, Hernando, and Levy Counties is obtained almost entirely from the Floridan aquifer. The aquifer is unconfined near the coast and semiconfined in the ridge area. Transmissivity ranges from 20,000 feet squared per day in the ridge area to greater than 2,000,000 feet squared per day near major springs. Changes in the potentiometric surface of the aquifer are small between the wet and dry seasons. Water quality within the study area is generally very good except immediately adjacent to the coast where saltwater from the Gulf of Mexico poses a threat to freshwater supply. This threat can be compensated for by placing well fields a sufficient distance away from the zone of transition from saltwater to freshwater so as not to reduce or reverse the hydraulic gradient in that zone. Computer models are presently available to help predict the extent of influence of ground-water withdrawals in an area. These may be used as management tools in planning ground-water development of the area. (USGS)

  7. Environmental and ground-water surveillance at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Dirkes, R.L.; Luttrell, S.P.

    1995-06-01

    Environmental and ground-water surveillance of the Hanford Site and surrounding region is conducted to demonstrate compliance with environmental regulations, confirm adherence to DOE environmental protection policies, support DOE environmental management decisions, and provide information to the public. Environmental surveillance encompasses sampling and analyzing for potential radiological and nonradiological chemical contaminants on and off the Hanford Site. Emphasis is placed on surveillance of exposure pathways and chemical constituents that pose the greatest risk to human health and the environment.

  8. Geology and ground-water resources of Richardson County, Nebraska

    Science.gov (United States)

    Emery, Philip A.

    1964-01-01

    Richardson County is in the extreme southeast corner of Nebraska. It has an area of 545 square miles, and in 1960 it had a population of 13,903. The county is in the physiographic region referred to as the Dissected Loess-covered Till Prairies. Major drainage consists of the Big Nemaha River, including its North and South Forks, and Muddy Creek. These streams flow southeastward and empty into the Missouri River, which forms the eastern boundary of the county. The climate of Richardson County is subhumid; the normal annual precipitation is about 35 inches. Agriculture is the chief industry, and corn is the principal crop. Pleistocene glacial drift, loess, and alluvial deposits mantle the bedrock except in the southern and southwestern parts of the county where the bedrock is at the surface. Ground water is obtained from glacial till, fluvioglacial material, terrace deposits, and coarse alluvial deposits, all of Pleistocene age--and some is obtained from bedrock aquifers of Pennsylvanian and Permian age. Adequate supplies of ground water are in many places difficult to locate because the water-bearing sands and gravels of Pleistocene age vary in composition and lack lateral persistence. Perched water tables are common in the upland areas and provide limited amounts of water to many of the shallow wells, Very few wells in bedrock yield adequate supplies, as the permeability of the rock is low and water that is more than a few tens of feet below the bedrock surface is highly mineralized. Recharge is primarily from local precipitation, and water levels in many wells respond rapidly to increased or decreased precipitation. The quality of the ground water is generally satisfactory for most uses, although all the water is hard, and iron and manganese concentrations, in some areas, are relatively high. Ground water is used mainly for domestic and stock purposes.

  9. Simulation of the ground-water-flow system in the Kalamazoo County area, Michigan

    Science.gov (United States)

    Luukkonen, Carol L.; Blumer, Stephen P.; Weaver, T.L.; Jean, Julie

    2004-01-01

    A ground-water-flow model was developed to investigate the ground-water resources of Kalamazoo County. Ground water is widely used as a source of water for drinking and industry in Kalamazoo County and the surrounding area. Additionally, lakes and streams are valued for their recreational and aesthetic uses. Stresses on the ground-water system, both natural and human-induced, have raised concerns about the long-term availability of ground water for people to use and for replenishment of lakes and streams. Potential changes in these stresses, including withdrawals and recharge, were simulated using a ground-water-flow model. Simulations included steady-state conditions (in which stresses remained constant and changes in storage were not included) and transient conditions (in which stresses changed in seasonal and monthly time scales and storage within the system was included). Steady-state simulations were used to investigate the long-term effects on water levels and streamflow of a reduction in recharge or an increase in pumping to projected 2010 withdrawal rates, withdrawal and application of water for irrigation, and a reduction in recharge in urban areas caused by impervious surfaces. Transient simulations were used to investigate changes in withdrawals to match seasonal and monthly patterns under various recharge conditions, and the potential effects of the use of water for irrigation over the summer months. With a reduction in recharge, simulated water levels declined over most of the model area in Kalamazoo County; with an increase in pumping, water levels declined primarily near pumping centers. Because withdrawals by wells intercept water that would have discharged possibly to a stream or lake, model simulations indicated that streamflow was reduced with increased withdrawals. With withdrawal and consumption of water for irrigation, simulated water levels declined. Assuming a reduction in recharge due to urbanization, water levels declined and flow to

  10. A Theoretic Model of Transport Logistics Demand

    Directory of Open Access Journals (Sweden)

    Natalija Jolić

    2006-01-01

    Full Text Available Concerning transport logistics as relation between transportand integrated approaches to logistics, some transport and logisticsspecialists consider the tenn tautological. However,transport is one of the components of logistics, along with inventories,resources, warehousing, infonnation and goods handling.Transport logistics considers wider commercial and operationalframeworks within which the flow of goods is plannedand managed. The demand for transport logistics services canbe valorised as highly qualitative, differentiated and derived.While researching transport phenomenon the implementationof models is inevitable and demand models highly desirable. Asa contribution to transport modelling this paper improves decisionmaking and planning in the transport logistics field.

  11. Photodegradation of dimethenamid-P in deionised and ground water

    Directory of Open Access Journals (Sweden)

    Glavaški O.S.

    2016-01-01

    Full Text Available The study of photodegradation of dimethenamid-P herbicide was performed in deionised and ground water using TiO2 as a catalyst under UV light. The effect of electron acceptor (H2O2, scavenger of •OH radicals (C2H5OH and scavenger of holes (NaCl and Na2SO4 as well as solution pH was analyzed. The photodegradation of dimethenamid-P was followed by HPLC. The formation of transformation products was followed using high performance liquid chromatography-electrospray mass spectrometry. Ion chromatography and total organic carbon measurements were used for the determination of the mineralization level. HPLC analysis showed the almost complete removal of herbicide after 90 min in deionised and ground water, while total organic carbon analysis showed that dimethenamid-P was mineralized 64 and 50 % in deionised and ground water, respectively. The ion chromatography results showed that the mineralization process leads to the formation of chloride, sulphate and nitrate anions during the process. Transformation products were identified and the degradation mechanism was proposed. [Projekat Ministarstva nauke Republike Srbije, br. 172013

  12. Trace organic chemicals contamination in ground water recharge.

    Science.gov (United States)

    Díaz-Cruz, M Silvia; Barceló, Damià

    2008-06-01

    Population growth and unpredictable climate changes will pose high demands on water resources in the future. Even at present, surface water is certainly not enough to cope with the water requirement for agricultural, industrial, recreational and drinking purposes. In this context, the usage of ground water has become essential, therefore, their quality and quantity has to be carefully managed. Regarding quantity, artificial recharge can guarantee a sustainable level of ground water, whilst the strict quality control of the waters intended for recharge will minimize contamination of both the ground water and aquifer area. However, all water resources in the planet are threatened by multiple sources of contamination coming from the extended use of chemicals worldwide. In this respect, the environmental occurrence of organic micropollutants such as pesticides, pharmaceuticals, industrial chemicals and their metabolites has experienced fast growing interest. In this paper an overview of the priority and emerging organic micropollutants in the different source waters used for artificial aquifer recharge purposes and in the recovered water is presented. Besides, some considerations regarding fate and removal of such compounds are also addressed.

  13. UMTRA Ground Water Project management action process document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    A critical U.S. Department of Energy (DOE) mission is to plan, implement, and complete DOE Environmental Restoration (ER) programs at facilities that were operated by or in support of the former Atomic Energy Commission (AEC). These facilities include the 24 inactive processing sites the Uranium Mill Tailings Radiation Control Act (UMTRCA) (42 USC Section 7901 et seq.) identified as Title I sites, which had operated from the late 1940s through the 1970s. In UMTRCA, Congress acknowledged the potentially harmful health effects associated with uranium mill tailings and directed the DOE to stabilize, dispose of, and control the tailings in a safe and environmentally sound manner. The UMTRA Surface Project deals with buildings, tailings, and contaminated soils at the processing sites and any associated vicinity properties (VP). Surface remediation at the processing sites will be completed in 1997 when the Naturita, Colorado, site is scheduled to be finished. The UMTRA Ground Water Project was authorized in an amendment to the UMTRCA (42 USC Section 7922(a)), when Congress directed DOE to comply with U.S. Environmental Protection Agency (EPA) ground water standards. The UMTRA Ground Water Project addresses any contamination derived from the milling operation that is determined to be present at levels above the EPA standards.

  14. [Metal contamination of the ground water in Mohammedia (Morocco)].

    Science.gov (United States)

    Serghini, Amal; Fekhaoui, Mohammed; El Abidi, Abdellah; Tahri, Latifa; Bouissi, Mostafa; El Houssine, Zaid

    2003-01-01

    This aim of this study was to assess the heavy metal contamination of the ground water in the Moroccan city of Mohammedia and its relation to the highly developed industrial and domestic activities in the region. Six heavy metals, Cu, Zn, Cd, Hg, Fe and Pb, were assayed in the waters of 19 wells throughout the city, in industrial areas, public landfills, and residential zones. Four sampling campaigns were conducted between January and May 1999. Analysis of the heavy metal levels revealed a causal relation between the human activities at the sites studied and the degree of contamination recorded. The sites in the industrial areas had elevated concentrations of Fe, Zn, Cu or Pb and most often a combination of at least two of these at a single site. Moreover, the spatial distribution of this pollution showed water in S7 areas to be high in iron and that in S5 and S7 (industrial) areas high in mercury. The concentrations measured are respectively 2.5 and 3-5 times greater than the Maximum Acceptable Concentration (MAC) recommended by WHO for potable water. This work has conclusively proven the presence of dangerous heavy metal contamination of the ground water supply in the area of Mohammedia; it demonstrates the need for conservation and antipollution measures aimed against heavy metal contamination of the overall water supply and in particular the ground water.

  15. Geochemical characterization of ground-water flow in the Santa Fe Group aquifer system, Middle Rio Grande Basin, New Mexico

    Science.gov (United States)

    Plummer, L. Niel; Bexfield, Laura M.; Anderholm, Scott K.; Sanford, Ward E.; Busenberg, Eurybiades

    2004-01-01

    Chemical and isotopic data were obtained from ground water and surface water throughout the Middle Rio Grande Basin (MRGB), New Mexico, and supplemented with selected data from the U.S. Geological Survey (USGS) National Water Information System (NWIS) and City of Albuquerque water-quality database in an effort to refine the conceptual model of ground-water flow in the basin. The ground-water data collected as part of this study include major- and minor-element chemistry (30 elements), oxygen-18 and deuterium content of water, carbon-13 content and carbon-14 activity of dissolved inorganic carbon, sulfur-34 content of dissolved sulfate, tritium, and dissolved atmospheric gases including nitrogen, argon, helium, chlorofluorocarbons,

  16. 地下水源热泵系统热平衡模拟三维数值模型%Three-dimensional numerical model for heat balance simulation of ground-water heat pump

    Institute of Scientific and Technical Information of China (English)

    骆祖江; 李伟; 王琰; 张德忠; 方连育

    2014-01-01

    In order to simulate and predict the change law of heat balance accurately and avoid heat penetration phenomenon during the groundwater heat pump operation, a three dimensional coupling numerical model of groundwater seepage and thermal transport was established and applied to the demonstration project of groundwater heat pump system in Zhengding, Hebei province. The model was based on the groundwater seepage theory, saturated water-bearing medium thermal transport theory and Terzaghi effective stress principle, combined with the design scheme and operation situation of groundwater heat pump, the future heat balance development tendency of groundwater heat pump system under three different conditions was forecasted and analyzed. The water temperature difference between the pumping well and recharge well reduced by 20%(eight degree centigrade) or increased by 20%(twelve degree centigrade) was the first condition which means the cooling and heating load was kept constant. Second condition was the water temperature difference between pumping well and recharge well confirmed and the circulating water volume increased by 20%, or the volume of circulating water kept constant and water temperature difference between pumping well and recharge well increased 20%, which means the cooling and heating load was increased. Meanwhile, in the third condition, the cooling and heating load was reduced. The water temperature difference between the pumping well and recharge well was confirmed and the volume of circulating water reduced 20%, or the water temperature difference between pumping well and recharge well reduced 20%while the circulating water volume kept constant. It was shown that there is a heat penetration phenomenon between the pumping well and recharge well in the demonstration project under the condition of design scheme, which has one pumping well and one recharge well. When the cooling and heating load of the groundwater heat pump system is confirmed, increasing 20

  17. Estimated potentiometric surface by D'Agnese and others (1998), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — D'Agnese and others (1998) developed a potentiometric surface to conceptualize the regional ground-water flow system and to construct numerical flow models of the...

  18. Flow system boundary by D'Agnese and others (1997) for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the flow-system boundary encompassing the regional ground-water flow model by D'Agnese and others (1997). The boundary encompasses an...

  19. Modelling of Transport Projects Uncertainties

    DEFF Research Database (Denmark)

    Salling, Kim Bang; Leleur, Steen

    2009-01-01

    This paper proposes a new way of handling the uncertainties present in transport decision making based on infrastructure appraisals. The paper suggests to combine the principle of Optimism Bias, which depicts the historical tendency of overestimating transport related benefits and underestimating...... investment costs, with a quantitative risk analysis based on Monte Carlo simulation and to make use of a set of exploratory scenarios. The analysis is carried out by using the CBA-DK model representing the Danish standard approach to socio-economic cost-benefit analysis. Specifically, the paper proposes...... to supplement Optimism Bias and the associated Reference Class Forecasting (RCF) technique with a new technique that makes use of a scenario-grid. We tentatively introduce and refer to this as Reference Scenario Forecasting (RSF). The final RSF output from the CBA-DK model consists of a set of scenario...

  20. Ground water/surface water responses to global climate simulations, Santa Clara-Calleguas Basin, Ventura, California

    Science.gov (United States)

    Hanson, R.T.; Dettinger, M.D.

    2005-01-01

    Climate variations can play an important, if not always crucial, role in successful conjunctive management of ground water and surface water resources. This will require accurate accounting of the links between variations in climate, recharge, and withdrawal from the resource systems, accurate projection or predictions of the climate variations, and accurate simulation of the responses of the resource systems. To assess linkages and predictability of climate influences on conjunctive management, global climate model (GCM) simulated precipitation rates were used to estimate inflows and outflows from a regional ground water model (RGWM) of the coastal aquifers of the Santa ClaraCalleguas Basin at Ventura, California, for 1950 to 1993. Interannual to interdecadal time scales of the El Nin??o Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) climate variations are imparted to simulated precipitation variations in the Southern California area and are realistically imparted to the simulated ground water level variations through the climate-driven recharge (and discharge) variations. For example, the simulated average ground water level response at a key observation well in the basin to ENSO variations of tropical Pacific sea surface temperatures is 1.2 m/??C, compared to 0.9 m/??C in observations. This close agreement shows that the GCM-RGWM combination can translate global scale climate variations into realistic local ground water responses. Probability distributions of simulated ground water level excursions above a local water level threshold for potential seawater intrusion compare well to the corresponding distributions from observations and historical RGWM simulations, demonstrating the combination's potential usefulness for water management and planning. Thus the GCM-RGWM combination could be used for planning purposes and - when the GCM forecast skills are adequate - for near term predictions.

  1. Ground-Water Resource Assessment in the Rio Grande de Manati Alluvial Plain, Rio Arriba Saliente Area, Puerto Rico

    Science.gov (United States)

    Torres-Gonzalez, Sigfredo; Gómez-Gómez, Fernando; Warne, Andrew G.

    2002-01-01

    the present study indicate that fecal coliform and fecal streptococcus concentrations are within the standards for surface water intended for use (or with the potential for use) as a raw source of public water supply in Puerto Rico. If a production well were constructed in the study area, it would be located close to the river channel (within 500 to 800 feet). Pumping from the porous and permeable alluvial aquifer close to the river channel could substantially enhance recharge from the Rio Grande de Manati channel to the aquifer. Enhanced recharge could shorten travel times for ground water in the aquifer, which might not allow sufficient time to attenuate bacteria and viruses. Travel times for bacteria moving from the river channel to a hypothetical production well were estimated using the numerical transport model MODFLOW/MT3DMS with an uncalibrated model of the alluvial aquifer. The model assumes a well pumping at 1 cubic foot per second. The transport of particles from the river to the well is most sensitive to the porosity of the aquifer and the pumping rate of the well. Sensitivity analysis indicates that a decrease in pumpage will increase the time of travel for particles to move from the river to the pumping well. The model indicates that the leading edge of a plume would reach the production well in about 40 days assuming a porosity of 0.20, 60 days assuming a porosity of 0.275, and about 70 days assuming a porosity of 0.35. If the well were moved 50 feet further from the river, the leading edge of the plume would reach the well in about 50 days assuming a porosity of 0.20 and about 70 days assuming a porosity of 0.275. These estimates are considered worse case estimates because no decay rate was included in the simulation, and because the hypothetical well was located in the center of the alluvial plain rather than further eastward, away from the river channel.

  2. Geospatial Database of Ground-Water Altitude and Depth-to-Ground-Water Data for Utah, 1971-2000

    Science.gov (United States)

    Buto, Susan G.; Jorgensen, Brent E.

    2007-01-01

    A geospatial database of ground-water-level altitude and depth-to-ground-water data for Utah was developed. Water-level contours from selected published reports were converted to digital Geographic Information System format and attributes describing the contours were added. Water-level altitude values were input to an inverse distance weighted interpolator to create a raster of interpolated water-level altitude for each report. The water-level altitude raster was subtracted from digital land-surface altitude data to obtain depth-to-water rasters for each study. Comparison of the interpolated rasters to actual water-level measurements shows that the interpolated water-level altitudes are well correlated with measured water-level altitudes from the same time period. The data can be downloaded and displayed in any Geographic Information System or can be explored by downloading a data package and map from the U.S. Geological Survey.

  3. Geology and ground-water resources of Washington County, Colorado

    Science.gov (United States)

    McGovern, Harold E.

    1964-01-01

    Washington County, in northeastern Colorado, has an area of 2,520 square miles. The eastern two-thirds of the county, part of the High Plains physiographic section, is relatively flat and has been moderately altered by the deposition of loess and dune sand, and by stream erosion. The western one-third is a part of the South Platte River basin and has been deeply dissected by tributary streams. The soils and climate of the county are generally suited for agriculture, which is the principal industry. The rocks that crop out in the county influence the availability of ground water. The Pierre Shale, of Late Cretaceous age, underlies the entire area and ranges in thickness from 2,000 to 4,500 feet. This dense shale is a barrier to the downward movement of water and yields little or no water to wells. The Chadron Formation, of Oligocene age, overlies the Pierre Shale in the northern and central parts of the area. The thickness of the formation ranges from a few feet to about 300 feet. Small to moderate quantities of water are available from the scattered sand lenses and from the highly fractured zones of the siltstone. The Ogallala Formation, of Pliocene age, overlies the Chadron Formation and in Washington County forms the High Plains section of the Great Plains province. The thickness of the Ogallala Formation ranges from 0 to about 400 feet, and the yield from wells ranges from a few gallons per hour to about 1,500 gpm. Peorian loess, of Pleistocene age, and dune sand, of Pleistocene to Recent age, mantle a large pan of the county and range in thickness from a few inches to about 120 feet Although the loess and dune sand yield little water to wells, they absorb much of the precipitation and conduct the water to underlying formations. Alluvium, of Pleistocene and Recent age, occupies most of the major stream valleys in thicknesses of a few feet to about 250 feet. The yield of wells tapping the alluvium ranges from a few gallons per minute to about 3,000 gpm, according

  4. Water management, agriculture, and ground-water supplies

    Science.gov (United States)

    Nace, Raymond L.

    1960-01-01

    Encyclopedic data on world geography strikingly illustrate the drastic inequity in the distribution of the world's water supply. About 97 percent of the total volume of water is in the world's oceans. The area of continents and islands not under icecaps, glaciers, lakes, and inland seas is about 57.5 million square miles, of which 18 million (36 percent) is arid to semiarid. The total world supply of water is about 326.5 million cubic miles, of which about 317 million is in the oceans and about 9.4 million is in the land areas. Atmospheric moisture is equivalent to only about 3,100 cubic miles of water. The available and accessible supply of ground water in the United States is somewhat more than 53,000 cubic miles (about 180 billion acre ft). The amount of fresh water on the land areas of the world at any one time is roughly 30,300 cubic miles and more than a fourth of this is in large fresh-water lakes on the North American Continent. Annual recharge of ground water in the United States may average somewhat more than 1 billion acre-feet yearly, but the total volume of ground water in storage is equivalent to all the recharge in about the last 160 years. This accumulation of ground water is the nation's only reserve water resource, but already it is being withdrawn or mined on a large scale in a few areas. The principal withdrawals of water in the United States are for agriculture and industry. Only 7.4 percent of agricultural land is irrigated, however; so natural soil moisture is the principal source of agricultural water, and on that basis agriculture is incomparably the largest water user. In view of current forecasts of population and industrial expansion, new commitments of water for agriculture should be scrutinized very closely, and thorough justification should be required. The 17 Western States no longer contain all the large irrigation developments. Nearly 10 percent of the irrigated area is in States east of the western bloc, chiefly in several

  5. Water management, agriculture, and ground-water supplies

    Science.gov (United States)

    Nace, Raymond L.

    1960-01-01

    Encyclopedic data on world geography strikingly illustrate the drastic inequity in the distribution of the world's water supply. About 97 percent of the total volume of water is in the world's oceans. The area of continents and islands not under icecaps, glaciers, lakes, and inland seas is about 57.5 million square miles, of which 18 million (36 percent) is arid to semiarid. The total world supply of water is about 326.5 million cubic miles, of which about 317 million is in the oceans and about 9.4 million is in the land areas. Atmospheric moisture is equivalent to only about 3,100 cubic miles of water. The available and accessible supply of ground water in the United States is somewhat more than 53,000 cubic miles (about 180 billion acre ft). The amount of fresh water on the land areas of the world at any one time is roughly 30,300 cubic miles and more than a fourth of this is in large fresh-water lakes on the North American Continent. Annual recharge of ground water in the United States may average somewhat more than 1 billion acre-feet yearly, but the total volume of ground water in storage is equivalent to all the recharge in about the last 160 years. This accumulation of ground water is the nation's only reserve water resource, but already it is being withdrawn or mined on a large scale in a few areas. The principal withdrawals of water in the United States are for agriculture and industry. Only 7.4 percent of agricultural land is irrigated, however; so natural soil moisture is the principal source of agricultural water, and on that basis agriculture is incomparably the largest water user. In view of current forecasts of population and industrial expansion, new commitments of water for agriculture should be scrutinized very closely, and thorough justification should be required. The 17 Western States no longer contain all the large irrigation developments. Nearly 10 percent of the irrigated area is in States east of the western bloc, chiefly in several

  6. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site in Lakeview, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    This Baseline Risk Assessment of Ground Water Contamination at the Uranium Mill Tailings Site in Lake view, Oregon evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site.

  7. Depth to ground water contours of hydrographic area 153, Diamond Valley, Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of depth to ground water contours for hydrographic-area (HA) 153, Diamond Valley, Nevada. These data represent static ground-water levels...

  8. Digital data set describing ground-water regions with unconsolidated watercourses in the conterminous US

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set describes ground-water regions in the United States defined by the U.S. Geological Survey. These ground-water regions are useful for dividing the...

  9. Ground-water hydraulics - A summary of lectures presented by John G. Ferris at short courses conducted by the Ground Water Branch, part 1, Theory

    Science.gov (United States)

    Knowles, D.B.

    1955-01-01

    The objective of the Ground Water Branch is to evaluate the occurrence, availability, and quality of ground water.  The science of ground-water hydrology is applied toward attaining that goal.  Although many ground-water investigations are of a qualitative nature, quantitative studies are necessarily an integral component of the complete evaluation of occurrence and availability.  The worth of an aquifer as a fully developed source of water depends largely on two inherent characteristics: its ability to store, and its ability to transmit water.  Furthermore, quantitative knowledge of these characteristics facilitates measurement of hydrologic entities such as recharge, leakage, evapotranspiration, etc.  It is recognized that these two characteristics, referred to as the coefficients of storage and transmissibility, generally provide the very foundation on which quantitative studies are constructed.  Within the science of ground-water hydrology, ground-water hydraulics methods are applied to determine these constats from field data.

  10. Areal studies aid protection of ground-water quality in Illinois, Indiana, and Wisconsin

    Science.gov (United States)

    Mills, Patrick C.; Kay, Robert T.; Brown, Timothy A.; Yeskis, Douglas J.

    1999-01-01

    In 1991, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, initiated studies designed to characterize the ground-water quality and hydrogeology in northern Illinois, and southern and eastern Wisconsin (with a focus on the north-central Illinois cities of Belvidere and Rockford, and the Calumet region of northeastern Illinois and northwestern Indiana). These areas are considered especially susceptible to ground-water contamination because of the high density of industrial and waste-disposal sites and the shallow depth to the unconsolidated sand and gravel aquifers and the fractured, carbonate bedrock aquifers that underlie the areas. The data and conceptual models of ground-water flow and contaminant distribution and movement developed as part of the studies have allowed Federal, State, and local agencies to better manage, protect, and restore the water supplies of the areas. Water-quality, hydrologic, geologic, and geophysical data collected as part of these areal studies indicate that industrial contaminants are present locally in the aquifers underlying the areas. Most of the contaminants, particularly those at concentrations that exceeded regulatory water-quality levels, were detected in the sand and gravel aquifers near industrial or waste-disposal sites. In water from water-supply wells, the contaminants that were present generally were at concentrations below regulatory levels. The organic compounds detected most frequently at concentrations near or above regulatory levels varied by area. Trichloroethene, tetrachloroethene, and 1,1,1-trichloroethane (volatile chlorinated compounds) were most prevalent in north-central Illinois; benzene (a petroleum-related compound) was most prevalent in the Calumet region. Differences in the type of organic compounds that were detected in each area likely reflect differences in the types of industrial sites that predominate in the areas. Nickel and aluminum were the trace metals

  11. SUTRA (Saturated-Unsaturated Transport). A Finite-Element Simulation Model for Saturated-Unsaturated, Fluid-Density-Dependent Ground-Water Flow with Energy Transport or Chemically-Reactive Single-Species Solute Transport.

    Science.gov (United States)

    2014-09-26

    Copies of this report can be . write to. purchased from: • Chief Hydrologist U.S, Geological Survey U.S. Geological Survey Open-File Services Section 431...request to the originating office at the following address: Chief Hydrologist - SUTRA U.S. Geological Survey 431 National Center Reston, VA 22092 Copies ...P P p p P P".. !Iol’e tor: fr sOl i ," ,ir p every third irv step and tor I’ each t’me step (NPCCYC=3 and NI (’ i =1 I: " - : 2 - 12 1

  12. Assessment of nitrification potential in ground water using short term, single-well injection experiments.

    Science.gov (United States)

    Smith, R L; Baumgartner, L K; Miller, D N; Repert, D A; Böhlke, J K

    2006-01-01

    Nitrification was measured within a sand and gravel aquifer on Cape Cod, MA, using a series of single-well injection tests. The aquifer contained a wastewater-derived contaminant plume, the core of which was anoxic and contained ammonium. The study was conducted near the downgradient end of the ammonium zone, which was characterized by inversely trending vertical gradients of oxygen (270 to 0 microM) and ammonium (19 to 625 microM) and appeared to be a potentially active zone for nitrification. The tests were conducted by injecting a tracer solution (ambient ground water + added constituents) into selected locations within the gradients using multilevel samplers. After injection, the tracers moved by natural ground water flow and were sampled with time from the injection port. Rates of nitrification were determined from changes in nitrate and nitrite concentration relative to bromide. Initial tests were conducted with (15)N-enriched ammonium; subsequent tests examined the effect of adding ammonium, nitrite, or oxygen above background concentrations and of adding difluoromethane, a nitrification inhibitor. In situ net nitrate production exceeded net nitrite production by 3- to 6- fold and production rates of both decreased in the presence of difluoromethane. Nitrification rates were 0.02-0.28 mumol (L aquifer)(-1) h(-1) with in situ oxygen concentrations and up to 0.81 mumol (L aquifer)(-1) h(-1) with non-limiting substrate concentrations. Geochemical considerations indicate that the rates derived from single-well injection tests yielded overestimates of in situ rates, possibly because the injections promoted small-scale mixing within a transport-limited reaction zone. Nonetheless, these tests were useful for characterizing ground water nitrification in situ and for comparing potential rates of activity when the tracer cloud included non-limiting ammonium and oxygen concentrations.

  13. Geology and ground-water resources in the Zebulon area, Georgia

    Science.gov (United States)

    Chapman, M.J.; Milby, B.J.; Peck, M.F.

    1993-01-01

    The current (1991) surface-water source of drinking-water supply for the city of Zebulon, Pike County, Georgia, no longer provides an adequate water supply and periodically does not meet water-quality standards. The hydrogeology of crystalline rocks in the Zebulon area was evaluated to assess the potential of ground-water resources as a supplemental or alternative source of water to present surface-water supplies. As part of the ground-water resource evaluation, well location and construction data were compiled, a geologic map was constructed, and ground water was sampled and analyzed. Three mappable geologic units delineated during this study provide a basic understanding of hydrogeologic settings in the Zebulon area. Rock types include a variety of aluminosilicate schists, granitic rocks, amphibolites/honblende gneisses, and gondites. Several geologic features that may enhance ground-water availability were identified in the study area. These features include contacts between contrasting rock types, where a high degree of differential weathering has occurred, and well-developed structural features, such as foliation and jointing are present. High-yielding wells (greater than 25 gallons per minute) and low-yielding wells (less than one gallon per minute) were located in all three geologic units in a variety of topographic settings. Well yields range from less than one gallon per minute to 250 gallons per minute. The variable total depths and wide ranges of casing depths of the high-yielding wells are indicative of variations in depths to water-bearing zones and regolith thicknesses, respectively. The depth of water-bearing zones is highly variable, even on a local scale. Analyses of ground-water samples indicate that the distribution of iron concentration is as variable as well yield in the study area and does not seem to be related to a particular rock type. Iron concentrations in ground-water samples ranged from 0.02 to 5.3 milligrams per liter. Both iron

  14. 40 CFR 258.53 - Ground-water sampling and analysis requirements.

    Science.gov (United States)

    2010-07-01

    ....53 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program must... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water sampling and analysis requirements. 258.53 Section 258.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  15. 40 CFR 264.97 - General ground-water monitoring requirements.

    Science.gov (United States)

    2010-07-01

    ... FACILITIES Releases From Solid Waste Management Units § 264.97 General ground-water monitoring requirements. The owner or operator must comply with the following requirements for any ground-water monitoring... 40 Protection of Environment 25 2010-07-01 2010-07-01 false General ground-water...

  16. Hydrogeology and simulation of ground-water flow at the Gettysburg Elevator Plant Superfund Site, Adams County, Pennsylvania

    Science.gov (United States)

    Low, Dennis J.; Goode, Daniel J.; Risser, Dennis W.

    2000-01-01

    Ground water in Triassic-age sedimentary fractured-rock aquifers in the area of Gettysburg, Pa., is used as drinking water and for industrial and commercial supply. In 1983, ground water at the Gettysburg Elevator Plant was found by the Pennsylvania Department of Environmental Resources to be contaminated with trichloroethene, 1,1,1-trichloroethane, and other synthetic organic compounds. As part of the U.S. Environmental Protection Agency?s Comprehensive Environmental Response, Compensation, and Liability Act, 1980 process, a Remedial Investigation was completed in July 1991, a method of site remediation was issued in the Record of Decision dated June 1992, and a Final Design Report was completed in May 1997. In cooperation with the U.S. Environmental Protection Agency in the hydrogeologic assessment of the site remediation, the U.S. Geological Survey began a study in 1997 to determine the effects of the onsite and offsite extraction wells on ground-water flow and contaminant migration from the Gettysburg Elevator Plant. This determination is based on hydrologic and geophysical data collected from 1991 to 1998 and on results of numerical model simulations of the local ground-water flow-system. The Gettysburg Elevator Site is underlain by red, green, gray, and black shales of the Heidlersburg Member of the Gettysburg Formation. Correlation of natural-gamma logs indicates the sedimentary rock strike about N. 23 degrees E. and dip about 23 degrees NW. Depth to bedrock onsite commonly is about 6 feet but offsite may be as deep as 40 feet. The ground-water system consists of two zones?a thin, shallow zone composed of soil, clay, and highly weathered bedrock and a thicker, nonweathered or fractured bedrock zone. The shallow zone overlies the bedrock zone and truncates the dipping beds parallel to land surface. Diabase dikes are barriers to ground-water flow in the bedrock zone. The ground-water system is generally confined or semi-confined, even at shallow depths. Depth

  17. Ground-water resources of Catron County, New Mexico

    Science.gov (United States)

    Basabilvazo, G.T.

    1997-01-01

    This report describes the occurrence, availability, and quality of ground-water and related surface-water resources in Catron County, the largest county in New Mexico. The county is located in the Lower Colorado River Basin and the Rio Grande Basin, and the Continental Divide is the boundary between the two river basins. Increases in water used for mining activities (coal, mineral, and geothermal), irrigated agriculture, reservoir construction, or domestic purposes could affect the quantity or quality of ground- water and surface-water resources in the county. Parts of seven major drainage basins are within the two regional river basins in the county--Carrizo Wash, North Plains, Rio Salado, San Agustin, Alamosa Creek, Gila, and San Francisco Basins. The San Francisco, Gila, and Tularosa Rivers typically flow perennially. During periods of low flow, most streamflow is derived from baseflow. The stream channels of the Rio Salado and Carrizo Wash Basins are commonly perennial in their upper reaches and ephemeral in their lower reaches. Largo Creek in the Carrizo Wash Basin is perennial downstream from Quemado Lake and ephemeral in the lower reaches. Aquifers in Catron County include Quaternary alluvium and bolson fill; Quaternary to Tertiary Gila Conglomerate; Tertiary Bearwallow Mountain Andesite, Datil Group, and Baca Formation; Cretaceous Mesaverde Group, Crevasse Canyon Formation, Gallup Sandstone, Mancos Shale, and Dakota Sandstone; Triassic Chinle Formation; and undifferentiated rocks of Permian age. Water in the aquifers in the county generally is unconfined; however, confined conditions may exist where the aquifers are overlain by other units of lower permeability. Yields of ground water from the Quaternary alluvium in the county range from 1 to 375 gallons per minute. Yields of ground water from the alluvium in the Carrizo Wash Basin are as much as 250 gallons per minute for short time periods. North of the Plains of San Agustin, ground-water yields from the

  18. Estimating nitrogen loading to ground water and assessing vulnerability to nitrate contamination in a large karstic springs Basin, Florida

    Science.gov (United States)

    Katz, B.G.; Sepulveda, A.A.; Verdi, R.J.

    2009-01-01

    A nitrogen (N) mass-balance budget was developed to assess the sources of N affecting increasing ground-water nitrate concentrations in the 960-km 2 karstic Ichetucknee Springs basin. This budget included direct measurements of N species in rainfall, ground water, and spring waters, along with estimates of N loading from fertilizers, septic tanks, animal wastes, and the land application of treated municipal wastewater and residual solids. Based on a range of N leaching estimates, N loads to ground water ranged from 262,000 to 1.3 million kg/year; and were similar to N export from the basin in spring waters (266,000 kg/year) when 80-90% N losses were assumed. Fertilizers applied to cropland, lawns, and pine stands contributed about 51% of the estimated total annual N load to ground water in the basin. Other sources contributed the following percentages of total N load to ground water: animal wastes, 27%; septic tanks, 12%; atmospheric deposition, 8%; and the land application of treated wastewater and biosolids, 2%. Due to below normal rainfall (97.3 cm) during the 12-month rainfall collection period, N inputs from rainfall likely were about 30% lower than estimates for normal annual rainfall (136 cm). Low N-isotope values for six spring waters (??15N-NO3 = 3.3 to 6.3???) and elevated potassium concentrations in ground water and spring waters were consistent with the large N contribution from fertilizers. Given ground-water residence times on the order of decades for spring waters, possible sinks for excess N inputs to the basin include N storage in the unsaturated zone and parts of the aquifer with relatively sluggish ground-water movement and denitrification. A geographical-based model of spatial loading from fertilizers indicated that areas most vulnerable to nitrate contamination were located in closed depressions containing sinkholes and other dissolution features in the southern half of the basin. ?? 2009 American Water Resources Association.

  19. Modelling of radon transport in porous media

    NARCIS (Netherlands)

    van der Graaf, E.R.; de Meijer, R.J.; Katase, A; Shimo, M

    1998-01-01

    This paper aims to describe the state of the art of modelling radon transport in soil on basis of multiphase radon transport equations. Emphasis is given to methods to obtain a consistent set of input parameters needed For such models. Model-measurement comparisons with the KVI radon transport Facil

  20. Modelling of radon transport in porous media

    NARCIS (Netherlands)

    van der Graaf, E.R.; de Meijer, R.J.; Katase, A; Shimo, M

    1998-01-01

    This paper aims to describe the state of the art of modelling radon transport in soil on basis of multiphase radon transport equations. Emphasis is given to methods to obtain a consistent set of input parameters needed For such models. Model-measurement comparisons with the KVI radon transport Facil

  1. Salinity of the ground water in western Pinal County, Arizona

    Science.gov (United States)

    Kister, Lester Ray; Hardt, W.F.

    1966-01-01

    The chemical quality of the ground water in western Pinal County is nonuniform areally and stratigraphically. The main areas of highly mineralized water are near Casa Grande and near Coolidge. Striking differences have been noted in the quality of water from different depths in the same well. Water from one well, (D-6-7) 25cdd, showed an increase in chloride content from 248 ppm (parts per million) at 350 feet below the land surface to 6,580 ppm at 375 feet; the concentration of chloride increased to 10,400 ppm at 550 feet below the land surface. This change was accompanied by an increase in the total dissolved solids as indicated by conductivity measurements. The change in water quality can be correlated with sediment types. The upper and lower sand and gravel units seem to yield water of better quality than the intermediate silt and clay unit. In places the silt and clay unit contains zones of gypsum and common table salt. These zones yield water that contains large amounts of the dissolved minerals usually associated with water from playa deposits. Highly mineralized ground water in an area near Casa Grande has moved southward and westward as much as 4 miles. Similar water near Coolidge has moved a lesser distance. Good management practices and proper use of soil amendments have made possible the use of water that is high in salinity and alkali hazard for agricultural purposes in western Pinal County. The fluoride content of the ground water in western Pinal County is usually low; however, water from wells that penetrate either the bedrock or unconsolidated sediments that contain certain volcanic rocks may have as much as 9 ppm of fluoride.

  2. Transport Properties for Combustion Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J.; Bastein, L.; Price, P.N.

    2010-02-19

    This review examines current approximations and approaches that underlie the evaluation of transport properties for combustion modeling applications. Discussed in the review are: the intermolecular potential and its descriptive molecular parameters; various approaches to evaluating collision integrals; supporting data required for the evaluation of transport properties; commonly used computer programs for predicting transport properties; the quality of experimental measurements and their importance for validating or rejecting approximations to property estimation; the interpretation of corresponding states; combination rules that yield pair molecular potential parameters for unlike species from like species parameters; and mixture approximations. The insensitivity of transport properties to intermolecular forces is noted, especially the non-uniqueness of the supporting potential parameters. Viscosity experiments of pure substances and binary mixtures measured post 1970 are used to evaluate a number of approximations; the intermediate temperature range 1 < T* < 10, where T* is kT/{var_epsilon}, is emphasized since this is where rich data sets are available. When suitable potential parameters are used, errors in transport property predictions for pure substances and binary mixtures are less than 5 %, when they are calculated using the approaches of Kee et al.; Mason, Kestin, and Uribe; Paul and Warnatz; or Ern and Giovangigli. Recommendations stemming from the review include (1) revisiting the supporting data required by the various computational approaches, and updating the data sets with accurate potential parameters, dipole moments, and polarizabilities; (2) characterizing the range of parameter space over which the fit to experimental data is good, rather than the current practice of reporting only the parameter set that best fits the data; (3) looking for improved combining rules, since existing rules were found to under-predict the viscosity in most cases; (4

  3. Directions in Radiation Transport Modelling

    Directory of Open Access Journals (Sweden)

    P Nicholas Smith

    2016-12-01

    More exciting advances are on the horizon to increase the power of simulation tools. The advent of high performance computers is allowing bigger, higher fidelity models to be created, if the challenges of parallelization and memory management can be met. 3D whole core transport modelling is becoming possible. Uncertainty quantification is improving with large benefits to be gained from more accurate, less pessimistic estimates of uncertainty. Advanced graphical displays allow the user to assimilate and make sense of the vast amounts of data produced by modern modelling tools. Numerical solvers are being developed that use goal-based adaptivity to adjust the nodalisation of the system to provide the optimum scheme to achieve the user requested accuracy on the results, thus removing the need to perform costly convergence studies in space and angle etc. More use is being made of multi-physics methods in which radiation transport is coupled with other phenomena, such as thermal-hydraulics, structural response, fuel performance and/or chemistry in order to better understand their interplay in reactor cores.

  4. HANFORD SITE ENVIRONMENTAL DATA FOR CALENDAR YEAR 1989 - GROUND WATER

    Energy Technology Data Exchange (ETDEWEB)

    Bryce, R. W.; Gorst, W. R.

    1990-12-01

    In a continuing effort for the U.S. Department of Energy, Pacific Northwest Laboratory (PNL) is conducting ground-water monitoring at the Hanford Site, near Richland, Washington. This document contains the data listing of monitoring results obtained by PNL and Westinghouse Hanford Company during the period January through December 1989. Samples taken during 1989 were analyzed and reported by United States Testing Company, Inc., Richland, Washington. The data listing contains all chemical results (above contractual reporting limits) and radiochemical results (for which the result is larger than two times the total error).

  5. ENVIRONMENTAL SAFETY IMPROVEMENT OF SURFACE AND GROUND WATER CONTAMINATION AT THE AIRPORT AREA

    Directory of Open Access Journals (Sweden)

    Svitlana Madzhd

    2016-11-01

    Full Text Available Purpose: Taking into account that the airport "Kyiv" is located in one of the central districts of Kyiv and does not have clearly established sanitary protection zones, the problem of environmental pollution is topical and requires monitoring and research. In order to improve environmental compliance we made assessment of superficial and ground water quality in airport zone. Methods: Water quality was estimated by the biotesting method, hydrochemical analysis, and by oil products detection method. Results We performed analysis of wastewaters of airport “Kyiv” and superficial waters of river Nyvka. The samples took place: above the airport drainage, in the drainage place and below drainage place. We conducted assessment of ground waters, which are sources of water supply, on different distance from an airport (20 m, 500 m, 1000 m, 1500 min. Results of hydrochemical investigations of river indicated excess of nitrogen compounds content compare to regulatory discharge. Thus, it was defined excess of ammonia nitrogen in wastewaters in three times and in place of dispersion – in ten times; the content of nitrite nitrogen in the river sample after discharge exceeds in 22 times norm. Analysis of drinking water in airport zone has showed extremely high level of pollution by nitrite nitrogen exceeding norm in 7-17 times. After analysis it was defined high level of river pollution by oil products (in 26-32 times higher than MPC, and ground water in 1, 5-2 times. Results of biotesting confirmed data of hydrochemical investigations of superficial water state (acute toxicity was observed in drainage area and in place of drainage dispersion. Discussion: Increased content of nitrite indicates the strengthening of decomposition process of organic matter in conditions of slower oxidation of NO into NO. This parameter is major sanitary indicator which indicates pollution of water body. High content of such specific pollutant for aviation transport

  6. Up-gradient transport in a probabilistic transport model

    DEFF Research Database (Denmark)

    Gavnholt, J.; Juul Rasmussen, J.; Garcia, O.E.

    2005-01-01

    The transport of particles or heat against the driving gradient is studied by employing a probabilistic transport model with a characteristic particle step length that depends on the local concentration or heat gradient. When this gradient is larger than a prescribed critical value, the standard....... These results supplement recent works by van Milligen [Phys. Plasmas 11, 3787 (2004)], which applied Levy distributed step sizes in the case of supercritical gradients to obtain the up-gradient transport. (c) 2005 American Institute of Physics....

  7. Multi-Fraction Bayesian Sediment Transport Model

    Directory of Open Access Journals (Sweden)

    Mark L. Schmelter

    2015-09-01

    Full Text Available A Bayesian approach to sediment transport modeling can provide a strong basis for evaluating and propagating model uncertainty, which can be useful in transport applications. Previous work in developing and applying Bayesian sediment transport models used a single grain size fraction or characterized the transport of mixed-size sediment with a single characteristic grain size. Although this approach is common in sediment transport modeling, it precludes the possibility of capturing processes that cause mixed-size sediments to sort and, thereby, alter the grain size available for transport and the transport rates themselves. This paper extends development of a Bayesian transport model from one to k fractional dimensions. The model uses an existing transport function as its deterministic core and is applied to the dataset used to originally develop the function. The Bayesian multi-fraction model is able to infer the posterior distributions for essential model parameters and replicates predictive distributions of both bulk and fractional transport. Further, the inferred posterior distributions are used to evaluate parametric and other sources of variability in relations representing mixed-size interactions in the original model. Successful OPEN ACCESS J. Mar. Sci. Eng. 2015, 3 1067 development of the model demonstrates that Bayesian methods can be used to provide a robust and rigorous basis for quantifying uncertainty in mixed-size sediment transport. Such a method has heretofore been unavailable and allows for the propagation of uncertainty in sediment transport applications.

  8. Water-quality and hydrogeologic data used to evaluate the effects of farming systems on ground-water quality at the Management Systems Evaluation Area near Princeton,Minnesota, 1991-95

    Science.gov (United States)

    Landon, M.K.; Delin, G.N.; Nelson, K.J.; Regan, C.P.; Lamb, J.A.; Larson, S.J.; Capel, P.D.; Anderson, J.L.; Dowdy, R.H.

    1997-01-01

    The Minnesota Management Systems Evaluation Area (MSEA) project was part of a multi-scale, inter-agency initiative to evaluate the effects of agricultural management systems on water quality in the midwest corn belt. The research area was located in the Anoka Sand Plain about 5 kilometers southwest of Princeton, Minnesota. The ground-water-quality monitoring network within and immediately surrounding the research area consisted of 73 observation wells and 25 multiport wells. The primary objectives of the ground-water monitoring program at the Minnesota MSEA were to: (1) determine the effects of three farming systems on ground-water quality, and (2) understand the processes and factors affecting the loading, transport, and fate of agricultural chemicals in ground water at the site. This report presents well construction, geologic, water-level, chemical application, water-quality, and quality-assurance data used to evaluate the effects of farming systems on ground-water quality during 1991-95.

  9. Hydrology and simulation of ground-water flow in Kamas Valley, Summit County, Utah

    Science.gov (United States)

    Brooks, L.E.; Stolp, B.J.; Spangler, L.E.

    2003-01-01

    Kamas Valley, Utah, is located about 50 miles east of Salt Lake City and is undergoing residential development. The increasing number of wells and septic systems raised concerns of water managers and prompted this hydrologic study. About 350,000 acre-feet per year of surface water flows through Kamas Valley in the Weber River, Beaver Creek, and Provo River, which originate in the Uinta Mountains east of the study area. The ground-water system in this area consists of water in unconsolidated deposits and consolidated rock; water budgets indicate very little interaction between consolidated rock and unconsolidated deposits. Most recharge to consolidated rock occurs at higher altitudes in the mountains and discharges to streams and springs upgradient of Kamas Valley. About 38,000 acre-feet per year of water flows through the unconsolidated deposits in Kamas Valley. Most recharge is from irrigation and seepage from major streams; most discharge is to Beaver Creek in the middle part of the valley. Long-term water-level fluctuations range from about 3 to 17 feet. Seasonal fluctuations exceed 50 feet. Transmissivity varies over four orders of magnitude in both the unconsolidated deposits and consolidated rock and is typically 1,000 to 10,000 feet squared per day in unconsolidated deposits and 100 feet squared per day in consolidated rock as determined from specific capacity. Water samples collected from wells, streams, and springs had nitrate plus nitrite concentrations (as N) substantially less than 10 mg/L. Total and fecal coliform bacteria were detected in some surface-water samples and probably originate from livestock. Septic systems do not appear to be degrading water quality. A numerical ground-water flow model developed to test the conceptual understanding of the ground-water system adequately simulates water levels and flow in the unconsolidated deposits. Analyses of model fit and sensitivity were used to refine the conceptual and numerical models.

  10. Estimating the Probability of Elevated Nitrate Concentrations in Ground Water in Washington State

    Science.gov (United States)

    Frans, Lonna M.

    2008-01-01

    Logistic regression was used to relate anthropogenic (manmade) and natural variables to the occurrence of elevated nitrate concentrations in ground water in Washington State. Variables that were analyzed included well depth, ground-water recharge rate, precipitation, population density, fertilizer application amounts, soil characteristics, hydrogeomorphic regions, and land-use types. Two models were developed: one with and one without the hydrogeomorphic regions variable. The variables in both models that best explained the occurrence of elevated nitrate concentrations (defined as concentrations of nitrite plus nitrate as nitrogen greater than 2 milligrams per liter) were the percentage of agricultural land use in a 4-kilometer radius of a well, population density, precipitation, soil drainage class, and well depth. Based on the relations between these variables and measured nitrate concentrations, logistic regression models were developed to estimate the probability of nitrate concentrations in ground water exceeding 2 milligrams per liter. Maps of Washington State were produced that illustrate these estimated probabilities for wells drilled to 145 feet below land surface (median well depth) and the estimated depth to which wells would need to be drilled to have a 90-percent probability of drawing water with a nitrate concentration less than 2 milligrams per liter. Maps showing the estimated probability of elevated nitrate concentrations indicated that the agricultural regions are most at risk followed by urban areas. The estimated depths to which wells would need to be drilled to have a 90-percent probability of obtaining water with nitrate concentrations less than 2 milligrams per liter exceeded 1,000 feet in the agricultural regions; whereas, wells in urban areas generally would need to be drilled to depths in excess of 400 feet.

  11. Nitrate removal using Brevundimonas diminuta MTCC 8486 from ground water.

    Science.gov (United States)

    Kavitha, S; Selvakumar, R; Sathishkumar, M; Swaminathan, K; Lakshmanaperumalsamy, P; Singh, A; Jain, S K

    2009-01-01

    Brevundimonas diminuta MTCC 8486, isolated from marine soil of coastal area of Trivandrum, Kerala, was used for biological removal of nitrate from ground water collected from Kar village of Pali district, Rajasthan. The organism was found to be resistance for nitrate up to 10,000 mg L(-1). The optimum growth conditions for biological removal of nitrate were established in batch culture. The effect of carbon sources on nitrate removal was investigated using mineral salt medium (MSM) containing 500 mg L(-1) of nitrate to select the most effective carbon source. Among glucose and starch as carbon source, glucose at 1% concentration increased the growth (182+/-8.24 x 10(4) CFU mL(-1)) and induced maximum nitrate reduction (86.4%) at 72 h. The ground water collected from Kar village, Pali district of Rajasthan containing 460+/-5.92 mg L(-1) of nitrate was subjected to three different treatment processes in pilot scale (T1 to T3). Higher removal of nitrate was observed in T2 process (88%) supplemented with 1% glucose. The system was scaled up to 10 L pilot scale treatment plant. At 72 h the nitrate removal was observed to be 95% in pilot scale plant. The residual nitrate level (23+/-0.41 mg L(-1)) in pilot scale treatment process was found to be below the permissible limit of WHO.

  12. Factors influencing biological treatment of MTBE contaminated ground water

    Energy Technology Data Exchange (ETDEWEB)

    Stringfellow, William T.; Hines Jr., Robert D.; Cockrum, Dirk K.; Kilkenny, Scott T.

    2001-09-14

    Methyl tert-butyl ether (MTBE) contamination has complicated the remediation of gasoline contaminated sites. Many sites are using biological processes for ground water treatment and would like to apply the same technology to MTBE. However, the efficiency and reliability of MTBE biological treatment is not well documented. The objective of this study was to examine the operational and environmental variables influencing MTBE biotreatment. A fluidized bed reactor was installed at a fuel transfer station and used to treat ground water contaminated with MTBE and gasoline hydrocarbons. A complete set of chemical and operational data was collected during this study and a statistical approach was used to determine what variables were influencing MTBE treatment efficiency. It was found that MTBE treatment was more sensitive to up-set than gasoline hydrocarbon treatment. Events, such as excess iron accumulation, inhibited MTBE treatment, but not hydrocarbon treatment. Multiple regression analysis identified biomass accumulation and temperature as the most important variables controlling the efficiency of MTBE treatment. The influent concentration and loading of hydrocarbons, but not MTBE, also impacted MTBE treatment efficiency. The results of this study suggest guidelines for improving MTBE treatment. Long cell retention times in the reactor are necessary for maintaining MTBE treatment. The onset of nitrification only occurs when long cell retention times have been reached and can be used as an indicator in fixed film reactors that conditions favorable to MTBE treatment exist. Conversely, if the reactor can not nitrify, it is unlikely to have stable MTBE treatment.

  13. Geohydrology of the Central Oahu, Hawaii, Ground-Water Flow System and Numerical Simulation of the Effects of Additional Pumping

    Science.gov (United States)

    Oki, Delwyn S.

    1998-01-01

    A two-dimensional, finite-difference, ground-water flow model was developed for the central Oahu flow system, which is the largest and most productive ground-water flow system on the island. The model is based on the computer code SHARP which simulates both freshwater and saltwater flow. The ground-water model was developed using average pumping and recharge conditions during the 1950's, which was considered to be a steady-state period. For 1950's conditions, model results indicate that 62 percent (90.1 million gallons per day) of the discharge from the Schofield ground-water area flows southward and the remaining 38 percent (55.2 million gallons per day) of the discharge from Schofield flows northward. Although the contribution of recharge from infiltration of rainfall and irrigation water directly on top of the southern and northern Schofield ground-water dams was included in the model, the distribution of natural discharge from the Schofield ground-water area was estimated exclusive of the recharge on top of the dams. The model was used to investigate the long-term effects of pumping under future land-use conditions. Future recharge was conservatively estimated by assuming no recharge associated with agricultural activities. Future pumpage used in the model was based on the 1995-allocated rates. Model results indicate that the long-term effect of pumping at the 1995-allocated rates will be a reduction of water levels from present (1995) conditions in all ground-water areas of the central Oahu flow system. In the Schofield ground-water area, model results indicate that water levels could decline about 30 feet from the 1995 water-level altitude of about 275 feet. In the remaining ground-water areas of the central Oahu flow system, water levels may decline from less than 1 foot to as much as 12 feet relative to 1995 water levels. Model results indicate that the bottoms of several existing deep wells in northern and southern Oahu extend below the model

  14. Ground-water recharge in Fortymile Wash near Yucca Mountain, Nevada, 1992--1993

    Energy Technology Data Exchange (ETDEWEB)

    Savard, C.S.

    1994-12-31

    Quantification of the ground-water recharge from streamflow in the Fortymile Wash watershed will contribute to regional ground-water studies. Regional ground-water studies are an important component in the studies evaluating the ground-water flow system as a barrier to the potential migration of radionuclides from the potential underground high-level nuclear waste repository. Knowledge gained in understanding the ground-water recharge mechanisms and pathways in the Pah Canyon area, which is 10 km to the northeast of Yucca Mountain, may transfer to Yucca site specific studies. The current data collection network in Fortymile Canyon does not permit quantification of ground-water recharge, however a qualitative understanding of ground-water recharge was developed from these data.

  15. Business Models For Transport eBusiness

    OpenAIRE

    Dragan Cisic; Ivan Franciskovic; Ana Peric

    2003-01-01

    In this paper authors are presenting expectations from electronic commerce and its connotations on transport logistics. Based on trends, the relations between the companies in the international transport have to be strengthened using Internet business models. In the paper authors are investigating e-business information models for usage in transport

  16. Environmental isotopes as indicators for ground water recharge to fractured granite.

    Science.gov (United States)

    Ofterdinger, U S; Balderer, W; Loew, S; Renard, P

    2004-01-01

    To assess the contribution of accumulated winter precipitation and glacial meltwater to the recharge of deep ground water flow systems in fracture crystalline rocks, measurements of environmental isotope ratios, hydrochemical composition, and in situ parameters of ground water were performed in a deep tunnel. The measurements demonstrate the significance of these ground water recharge components for deep ground water flow systems in fractured granites of a high alpine catchment in the Central Alps, Switzerland. Hydrochemical and in situ parameters, as well as delta(18)O in ground water samples collected in the tunnel, show only small temporal variations. The precipitation record of delta(18)O shows seasonal variations of approximately 14% and a decrease of 0.23% +/- 0.03% per 100 m elevation gain. delta(2)H and delta(18)O in precipitation are well correlated and plot close to the meteoric water line, as well as delta(2)H and delta(18)O in ground water samples, reflecting the meteoric origin of the latter. The depletion of 18O in ground water compared to 18O content in precipitation during the ground water recharge period indicates significant contributions from accumulated depleted winter precipitation to ground water recharge. The hydrochemical composition of the encountered ground water, Na-Ca-HCO3-SO4(-F), reflects an evolution of the ground water along the flowpath through the granite body. Observed tritium concentrations in ground water range from 2.6 to 16.6 TU, with the lowest values associated with a local negative temperature anomaly and anomalous depleted 18O in ground water. This demonstrates the effect of local ground water recharge from meltwater of submodern glacial ice. Such localized recharge from glaciated areas occurs along preferential flowpaths within the granite body that are mainly controlled by observed hydraulic active shear fractures and cataclastic faults.

  17. Modeling energy transport in nanostructures

    Science.gov (United States)

    Pattamatta, Arvind

    Heat transfer in nanostructures differ significantly from that in the bulk materials since the characteristic length scales associated with heat carriers, i.e., the mean free path and the wavelength, are comparable to the characteristic length of the nanostructures. Nanostructure materials hold the promise of novel phenomena, properties, and functions in the areas of thermal management and energy conversion. Example of thermal management in micro/nano electronic devices is the use of efficient nanostructured materials to alleviate 'hot spots' in integrated circuits. Examples in the manipulation of heat flow and energy conversion include nanostructures for thermoelectric energy conversion, thermophotovoltaic power generation, and data storage. One of the major challenges in Metal-Oxide Field Effect Transistor (MOSFET) devices is to study the 'hot spot' generation by accurately modeling the carrier-optical phonon-acoustic phonon interactions. Prediction of hotspot temperature and position in MOSFET devices is necessary for improving thermal design and reliability of micro/nano electronic devices. Thermoelectric properties are among the properties that may drastically change at nanoscale. The efficiency of thermoelectric energy conversion in a material is measured by a non-dimensional figure of merit (ZT) defined as, ZT = sigmaS2T/k where sigma is the electrical conductivity, S is the Seebeck coefficient, T is the temperature, and k is the thermal conductivity. During the last decade, advances have been made in increasing ZT using nanostructures. Three important topics are studied with respect to energy transport in nanostructure materials for micro/nano electronic and thermoelectric applications; (1) the role of nanocomposites in improving the thermal efficiency of thermoelectric devices, (2) the interfacial thermal resistance for the semiconductor/metal contacts in thermoelectric devices and for metallic interconnects in micro/nano electronic devices, (3) the

  18. Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

    1984-04-01

    The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables.

  19. Supra regional ground water modelling - in-depth analysis of the groundwater flow patterns in eastern Smaaland. Comparison with different conceptual descriptions; Storregional grundvattenmodellering - foerdjupad analys av floedesfoerhaallanden i oestra Smaaland. Jaemfoerelse av olika konceptuella beskrivningar

    Energy Technology Data Exchange (ETDEWEB)

    Ericsson, Lars O. [Lars O Ericsson Consulting AB, Stockholm (Sweden); Holmen, Johan [Golder Associates, Uppsala (Sweden); Rhen, Ingvar; Blomquist, Niklas [SWECO VIAK, Stockholm (Sweden)

    2006-05-15

    One of many geoscientific questions in connection with the siting of a final repository for spent nuclear fuel in Sweden has to do with understanding the large-scale flow patterns of the naturally circulating groundwater. The recharge and discharge of the groundwater is therefore a subject for both SKB's research activities and the interest of the regulatory authorities. This report aims at providing an in-depth scientific analysis of the groundwater flow pattern based on the criteria and suitability indicators which SKB has previously presented with respect to recharge and discharge aspects in a supra regional perspective. The analysis was conducted within the framework of a project whose goals were to: evaluate conceptual simplifications and model uncertainties in supra regional groundwater modelling, and to carry out an in-depth and comprehensive analysis of regional flow conditions in eastern Smaaland. Achieving these goals has required an approach based on the use of available geoscientific data on the Smaaland region combined with an analysis of different conceptual assumptions and system descriptions. The following general conclusions can be drawn from the study and the applied methodology: The factor of greatest importance for the regional flow pattern (from repository depth) is the topography. The discharge areas are mainly found in the low-lying parts of the topography, along valleys, and the recharge areas occur on the heights. The topographic undulation is of greater importance than the properties of the conductivity field. Different lithological units, regional deformation zones, local heterogeneity, Quaternary deposits etc are of less importance than the undulation of the topography. For areas described and analyzed with the most realistic assumptions, the groundwater flow pattern can be described as a primarily local flow process. The median flow path length in the study is on the order of 2 km, and the fraction of supra regional flow paths

  20. Cholesterol transport in model membranes

    Science.gov (United States)

    Garg, Sumit; Porcar, Lionel; Butler, Paul; Perez-Salas, Ursula

    2010-03-01

    Physiological processes distribute cholesterol unevenly within the cell. The levels of cholesterol are maintained by intracellular transport and a disruption in the cell's ability to keep these normal levels will lead to disease. Exchange rates of cholesterol are generally studied in model systems using labeled lipid vesicles. Initially donor vesicles have all the cholesterol and acceptor vesicles are devoid of it. They are mixed and after some time the vesicles are separated and cholesterol is traced in each vesicle. The studies performed up to date have significant scatter indicating that the methodologies are not consistent. The present work shows in-situ Time-Resolved SANS studies of cholesterol exchange rates in unsaturated PC lipid vesicles. Molecular dynamics simulations were done to investigate the energetic and kinetic behavior of cholesterol in this system. This synergistic approach will provide insight into our efforts to understand cholesterol traffic.

  1. Aquifer tests and simulation of ground-water flow in Triassic sedimentary rocks near Colmar, Bucks and Montgomery Counties, Pennsylvania

    Science.gov (United States)

    Risser, Dennis W.; Bird, Philip H.

    2003-01-01

    This report presents the results of a study by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency to evaluate ground-water flow in Triassic sedimentary rocks near Colmar, in Bucks and Montgomery Counties, Pa. The study was conducted to help the U.S. Environmental Protection Agency evaluate remediation alternatives at the North Penn Area 5 Superfund Site near Colmar, where ground water has been contaminated by volatile organic solvents (primarily trichloroethene). The investigation focused on determining the (1) drawdown caused by separately pumping North PennWater Authority wells NP?21 and NP?87, (2) probable paths of groundwater movement under present-day (2000) conditions (with NP?21 discontinued), and (3) areas contributing recharge to wells if pumping from wells NP-21 or NP?87 were restarted and new recovery wells were installed. Drawdown was calculated from water levels measured in observation wells during aquifer tests of NP?21 and NP?87. The direction of ground-water flow was estimated by use of a three-dimensional ground-water-flow model. Aquifer tests were conducted by pumping NP?21 for about 7 days at 257 gallons per minute in June 2000 and NP?87 for 3 days at 402 gallons per minute in May 2002. Drawdown was measured in 45 observation wells during the NP?21 test and 35 observation wells during the NP?87 test. Drawdown in observation wells ranged from 0 to 6.8 feet at the end of the NP?21 test and 0.5 to 12 feet at the end of the NP?87 test. The aquifer tests showed that ground-water levels declined mostly in observation wells that were completed in the geologic units penetrated by the pumped wells. Because the geologic units dip about 27 degrees to the northwest, shallow wells up dip to the southeast of the pumped well showed a good hydraulic connection to the geologic units stressed by pumping. Most observation wells down dip from the pumping well penetrated units higher in the stratigraphic section that were not well

  2. A new formulation to compute self-potential signals associated with ground water flow

    Directory of Open Access Journals (Sweden)

    A. Bolève

    2007-06-01

    Full Text Available The classical formulation of the coupled hydroelectrical flow in porous media is based on a linear formulation of two coupled constitutive equations for the electrical current density and the seepage velocity of the water phase and obeying Onsager's reciprocity. This formulation shows that the streaming current density is controlled by the gradient of the fluid pressure of the water phase and a streaming current coupling coefficient that depends on the so-called zeta potential. Recently a new formulation has been introduced in which the streaming current density is directly connected to the seepage velocity of the water phase and to the excess of electrical charge per unit pore volume in the porous material. The advantages of this formulation are numerous. First this new formulation is more intuitive not only in terms of constitutive equation for the generalized Ohm's law but also in specifying boundary conditions for the influence of the flow field upon the streaming potential. With the new formulation, the streaming potential coupling coefficient shows a decrease of its magnitude with permeability in agreement with published results. The new formulation is also easily extendable to non-viscous laminar flow problems (high Reynolds number ground water flow in cracks for example and to unsaturated conditions with applications to the vadose zone. We demonstrate here that this formulation is suitable to model self-potential signals in the field. We investigate infiltration of water from an agricultural ditch, vertical infiltration of water into a sinkhole, and preferential horizontal flow of ground water in a paleochannel. For the three cases reported in the present study, a good match is obtained between the finite element simulations performed with the finite element code Comsol Multiphysics 3.3 and field observations. Finally, this formulation seems also very promising for the inversion of the geometry of ground water flow from the

  3. Expertise in exploiting ground water in Australian prehistory

    Energy Technology Data Exchange (ETDEWEB)

    Bandler, H. [Macquarie Univ., Sydney, NSW (Australia)

    2000-12-01

    The presence of human beings on the Australian continent has been established to go back to at least 40 000 years. Recent research has put this back to about 60 000 years B.P. (Before Present). With the awareness of living on an extremely arid continent, the need to satisfy water demands was a constant concern. Finding water for all members of the various groups, but especially for those living in the Australian inland with extremely low precipitation, was a perpetual challenge. Thus, in desert areas seeking, finding and protecting ground water was demanded continuously. Native wells were established and used for many centuries often when surface water had dried in nearby watercourses. A number of wells found in the Simpson Desert, with habitation around them until recently, are most interesting. In Central Australia, in the Cleland Hills, the location of habitation has been found at a huge rock shelter close to a rock hole providing permanent ground water when all other sources in the vicinity have dried out. It was scientifically established that this occupation goes back 22 000 years. These examples of obtaining ground water in Australian prehistory many thousands of years ago by Aborigines show a highly developed culture. (orig.) [German] Bisher wurde angenommen, dass die Besiedelung des australischen Kontinents durch den Menschen vor 40 000 Jahren begann. Neueste Untersuchungen datieren diesen Zeitpunkt jedoch auf 60 000 Jahre zurueck. Fuer das Leben auf diesem extrem trockenen Erdteil war die Sicherung des Wasserbedarfs von jeher existenziell. Lebenswichtiges Wasser zu finden war fuer alle Mitglieder der verschiedenen Bevoelkerungsgruppen, vor allem aber fuer diejenigen, die sich im australischen Hinterland ansiedelten, von hoechster Bedeutung. Grundwasser in der Wueste zu suchen, zu finden und zu schuetzen war oberstes Ziel. Urspruengliche Brunnen wurden errichtet und ueber Jahrhunderte hindurch genutzt, wenn alle anderen Wasserressourcen versiegten. Hierbei

  4. Electrochemical reduction of hexavalent chromium in ground water

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, S. [Lawrence Livermore National Lab., CA (United States)

    1994-12-01

    Electrochemical reduction of hexavalent chromium (Cr{sup +6}) to its trivalent state (Cr{sup +3}) is showing promising results in treating ground water at Lawrence Livermore National Laboratory`s (LLNL`s) Main Site. An electrolytic cell using stainless-steel and brass electrodes has been found to offer the most efficient reduction while yielding the least amount of precipitate. Trials have successfully lowered concentrations of Cr{sup +6} to below 11 parts per billion (micrograms/liter), the California state standard. We ran several trials to determine optimal voltage for running the cell; each trial consisted of applying a voltage between 6V and 48V for ten minutes through samples obtained at Treatment Facility C(TFC). No conclusive data has been obtained yet.

  5. Status of ground water in the 1100 Area

    Energy Technology Data Exchange (ETDEWEB)

    Law, A.G.

    1990-12-01

    This document contains the results of monthly sampling of 1100 Area Wells and ground water monitoring. Included is a table that presents all of the results of monthly sampling and analyses between April 1989 and May 1990, for four constituents selected to be most indicative of the potential for contamination from US Department of Energy facilities. The samples were collected from the three wells near the city of Richland well field. Also included is a table that presents a listing of the analytical results from sampling and analyses of five wells between April 1989, and May 1990 in the 1100 Area. The detection limit and drinking water standards or maximum contaminant level are also listed in the tables for each constituent.

  6. Ground-water status report, Pearl Harbor area, Hawaii, 1978

    Science.gov (United States)

    Soroos, Ronald L.; Ewart, Charles J.

    1979-01-01

    Increasing demand for freshwater in Hawaii has placed heavy stress on many of the State 's basal aquifer systems. The most heavily stressed of these systems is the Pearl Harbor on Oahu. The Pearl Harbor basal aquifer supplies as much as 277 million gallons per day. Since early in this century, spring discharge has been declining while pumpage has been increasing. Total ground-water discharge has remained steady despite short-term fluctuations. Some wells show general increases in chloride concentration while others remain steady. Chloride concentrations throughout the area show no apparent increase since 1970. Basal water head maps of the Pearl Harbor area clearly reflect the natural discharge points, which are the springs located along the shore near the center of Pearl Harbor. Basal-water hydrographs show a general decline of about 0.09 foot per year. This implies depletion of storage at a rate of about 25 million gallons per day. (USGS).

  7. Ground Water Monitoring Using Laser Fluorescence And Fiber Optics

    Science.gov (United States)

    Chudyk, Wayne; Pohlig, Kenneth; Rico, Nicola; Johnson, Gregory

    1989-01-01

    In-situ measurement of aromatic ground water contaminants, including the benzene, ethylbenzene, toluene, and xylenes (BTEX) fraction of gasoline, has been demonstrated using fiber optic systems. A prototype field instrument has shown that this method has advantages over traditional sampling and analysis. Problems encountered and solved include coupling of the laser energy into to fiber, sensor design, and detector configuration to optimize instrument sensitivity. The effects of sensor length, corresponding to well depth, on limits of detection are presented. Effects of potential interferences, including external fluorescence quenchers, are discuss-ed. The resolution of complex mixtures is addressed, with modifications to the detector shown to be effective in separation of groups of contaminants. Instrument design considerations include the need for portability, ruggedness at field sites, and ease of operation. The modular instrument design used is shown to help solve these potential problems, while maintaining analytical sensitivity and reproducibility. Modular optical system design has also shown to be useful when modifications are made. Changes in the detector as well as provisions for multiple laser sources have allowed a flexible system to be configured to meet analytical demands as they arise. Sensor design considerations included high ultraviolet transmission, physical flexibility, resistance to breakage, and resistance to chemical and/or biological fouling. The approach to these problem areas is presented, as well as discussion of the methods used to minimize effects of fiber solarization. Results of testing the field portable prototype are presented for a variety of typical ground water analysis sites, illustrating the usefulness of this new technology in environmental monitoring.

  8. Ground-water resources of Riverton irrigation project area, Wyoming

    Science.gov (United States)

    Morris, Donald Arthur; Hackett, O.M.; Vanlier, K.E.; Moulder, E.A.; Durum, W.H.

    1959-01-01

    The Riverton irrigation project area is in the northwestern part of the Wind River basin in west-central Wyoming. Because the annual precipitation is only about 9 inches, agriculture, which is the principal occupation in the area, is dependent upon irrigation. Irrigation by surface-water diversion was begum is 1906; water is now supplied to 77,716 acres and irrigation has been proposed for an additional 31,344 acres. This study of the geology and ground-water resources of the Riverton irrigation project, of adjacent irrigated land, and of nearby land proposed for irrigation was begun during the summer of 1948 and was completed in 1951. The purpose of the investigation was to evaluate the ground-water resources of the area and to study the factors that should be considered in the solution of drainage and erosional problems within the area. The Riverton irrigation project area is characterized by flat to gently sloping stream terraces, which are flanked by a combination of badlands, pediment slopes, and broad valleys. These features were formed by long-continued erosion in an arid climate of the essentially horizontal, poorly consolidated beds of the Wind River formation. The principal streams of the area flow south-eastward. Wind River and Fivemile Creek are perennial streams and the others are intermittent. Ground-water discharge and irrigation return flow have created a major problem in erosion control along Fivemile Creek. Similar conditions might develop along Muddy and lower Cottonwood Creeks when land in their drainage basins is irrigated. The bedrock exposed in the area ranges in age from Late Cretaceous to early Tertiary (middle Eocene). The Wind River formation of early and middle Eocene age forms the uppermost bedrock formation in the greater part of the area. Unconsolidated deposits of Quaternary age, which consist of terrace gravel, colluvium, eolian sand and silt. and alluvium, mantle the Wind River formation in much of the area. In the irrigated parts

  9. SATURATED ZONE FLOW AND TRANSPORT MODEL ABSTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    B.W. ARNOLD

    2004-10-27

    The purpose of the saturated zone (SZ) flow and transport model abstraction task is to provide radionuclide-transport simulation results for use in the total system performance assessment (TSPA) for license application (LA) calculations. This task includes assessment of uncertainty in parameters that pertain to both groundwater flow and radionuclide transport in the models used for this purpose. This model report documents the following: (1) The SZ transport abstraction model, which consists of a set of radionuclide breakthrough curves at the accessible environment for use in the TSPA-LA simulations of radionuclide releases into the biosphere. These radionuclide breakthrough curves contain information on radionuclide-transport times through the SZ. (2) The SZ one-dimensional (I-D) transport model, which is incorporated in the TSPA-LA model to simulate the transport, decay, and ingrowth of radionuclide decay chains in the SZ. (3) The analysis of uncertainty in groundwater-flow and radionuclide-transport input parameters for the SZ transport abstraction model and the SZ 1-D transport model. (4) The analysis of the background concentration of alpha-emitting species in the groundwater of the SZ.

  10. Logistics and Transport - a conceptual model

    DEFF Research Database (Denmark)

    Jespersen, Per Homann; Drewes, Lise

    2004-01-01

    This paper describes how the freight transport sector is influenced by logistical principles of production and distribution. It introduces new ways of understanding freight transport as an integrated part of the changing trends of mobility. By introducing a conceptual model for understanding...... the interaction between logistics and transport, it points at ways to over-come inherent methodological difficulties when studying this relation...

  11. Ground Water Flow Model at Fort Devens, Massachusetts

    Science.gov (United States)

    1993-05-24

    o a o 4 Q -- Oooo D :Oooo,3oooo a2o D Cla DOD Do"cli EN 0......... . ooooooorcl o o to oooo ...... ........ ..... .. 0 ::too aaoOoooooo 10 3 oC...CACLAE t LCA rUWS AQIE VELOCI’~~ VECTOR I VECT VETOR ANPS feetDECRASEDHYDAULI CONUCITVIT CONTACT O.: 930.8 DTE: O~T 59 / /4 * PR~t!CION ELL OCATON...569170 GLACIAL 215.6 WWTP WWTMW-O1A 570058 570236 GLACIAL 219.4 WWTP WWTMW-02 570064 570804 GLACIAL 222.6 WWTP WWTMW-02A 569921 571088 GLACIAL 223.4

  12. Algorithms for Model Calibration of Ground Water Simulators

    Science.gov (United States)

    2014-11-20

    cobian, and Jacobian-vector products are computed with a Monte Carlo simulation. This situation differs from the textbook case [5] in that one does not...Anderson acceleration is a natural method for multi-physics coupling (for example subsurface flow, chemistry , and heat transfer) when the individual physics...Online publication 7/12/2014. [11] J. Nance and C. T. Kelley, A sparse interpolation algorithm for dynamical simulations in compu- tational chemistry

  13. Water Use, Ground-Water Recharge and Availability, and Quality of Water in the Greenwich Area, Fairfield County, Connecticut and Westchester County, New York, 2000-2002

    Science.gov (United States)

    Mullaney, John R.

    2004-01-01

    Ground-water budgets were developed for 32 small basin-based zones in the Greenwich area of southwestern Connecticut, where crystalline-bedrock aquifers supply private wells, to determine the status of residential ground-water consumption relative to rates of ground-water recharge and discharge. Estimated residential ground-water withdrawals for small basins (averaging 1.7 square miles (mi2) ranged from 0 to 0.16 million gallons per day per square mile (Mgal/d/mi2). To develop these budgets, residential ground-water withdrawals were estimated using multiple-linear regression models that relate water use from public water supply to data on residential property characteristics. Average daily water use of households with public water supply ranged from 219 to 1,082 gallons per day (gal/d). A steady-state finite-difference ground-water-flow model was developed to track water budgets, and to estimate optimal values for hydraulic conductivity of the bedrock (0.05 feet per day) and recharge to the overlying till deposits (6.9 inches) using nonlinear regression. Estimated recharge rates to the small basins ranged from 3.6 to 7.5 inches per year (in/yr) and relate to the percentage of the basin underlain by coarse-grained glacial stratified deposits. Recharge was not applied to impervious areas to account for the effects of urbanization. Net residential ground-water consumption was estimated as ground-water withdrawals increased during the growing season, and ranged from 0 to 0.9 in/yr. Long-term average stream base flows simulated by the ground-water-flow model were compared to calculated values of average base flow and low flow to determine if base flow was substantially reduced in any of the basins studied. Three of the 32 basins studied had simulated base flows less than 3 in/yr, as a result of either ground-water withdrawals or reduced recharge due to urbanization. A water-availability criteria of the difference between the 30-day 2-year low flow and the recharge rate

  14. RADIONUCLIDE TRANSPORT MODELS UNDER AMBIENT CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    S. Magnuson

    2004-11-01

    The purpose of this model report is to document the unsaturated zone (UZ) radionuclide transport model, which evaluates, by means of three-dimensional numerical models, the transport of radioactive solutes and colloids in the UZ, under ambient conditions, from the repository horizon to the water table at Yucca Mountain, Nevada.

  15. Characterization of ground-water flow between the Canisteo Mine Pit and surrounding aquifers, Mesabi Iron Range, Minnesota

    Science.gov (United States)

    Jones, Perry M.

    2002-01-01

    The U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources, conducted a study to characterize ground-water flow conditions between the Canisteo Mine Pit, Bovey, Minnesota, and surrounding aquifers following mine abandonment. The objective of the study was to estimate the amount of steady-state, ground-water flow between the Canisteo Mine Pit and surrounding aquifers at pit water-level altitudes below the level at which surface-water discharge from the pit may occur. Single-well hydraulic tests and stream-hydrograph analyses were conducted to estimate horizontal hydraulic conductivities and ground-water recharge rates, respectively, for glacial aquifers surrounding the mine pit. Average hydraulic conductivity values ranged from 0.05 to 5.0 ft/day for sands and clays and from 0.01 to 121 ft/day for coarse sands, gravels, and boulders. The 15-year averages for the estimated annual recharge using the winter records and the entire years of record for defining baseflow recession rates were 7.07 and 7.58 in., respectively. These recharge estimates accounted for 25 and 27 percent, respectively, of the average annual precipitation for the 1968-82 streamflow monitoring period. Ground-water flow rates into and out of the mine pit were estimated using a calibrated steady-state, ground-water flow model simulating an area of approximately 75 mi2 surrounding the mine pit. The model residuals, or difference between simulated and measured water levels, for 15 monitoring wells adjacent to the mine pit varied between +28.65 and –3.78 ft. The best-match simulated water levels were within 4 ft of measured water levels for 9 of the 15 wells, and within 2 ft for 4 of the wells. The simulated net ground-water flow into the Canisteo Mine Pit was +1.34 ft3/s, and the net ground-water flow calculated from pit water levels measured between July 5, 1999 and February 25, 2001 was +5.4 ft3/s. Simulated water levels and ground-water flow to and from the mine

  16. Biological transportation networks: Modeling and simulation

    KAUST Repository

    Albi, Giacomo

    2015-09-15

    We present a model for biological network formation originally introduced by Cai and Hu [Adaptation and optimization of biological transport networks, Phys. Rev. Lett. 111 (2013) 138701]. The modeling of fluid transportation (e.g., leaf venation and angiogenesis) and ion transportation networks (e.g., neural networks) is explained in detail and basic analytical features like the gradient flow structure of the fluid transportation network model and the impact of the model parameters on the geometry and topology of network formation are analyzed. We also present a numerical finite-element based discretization scheme and discuss sample cases of network formation simulations.

  17. Ground-water discharge determined from measurements of evapotranspiration, other available hydrologic components, and shallow water-level changes, Oasis Valley, Nye County, Nevada

    Science.gov (United States)

    Reiner, S.R.; Laczniak, R.J.; DeMeo, G.A.; Smith, Jody L.; Elliott, P.E.; Nylund, W.E.; Fridrich, C.J.

    2002-01-01

    Oasis Valley is an area of natural ground-water discharge within the Death Valley regional ground-water flow system of southern Nevada and adjacent California. Ground water discharging at Oasis Valley is replenished from inflow derived from an extensive recharge area that includes the northwestern part of the Nevada Test Site (NTS). Because nuclear testing has introduced radionuclides into the subsurface of the NTS, the U.S. Department of Energy currently is investigating the potential transport of these radionuclides by ground water flow. To better evaluate any potential risk associated with these test-generated contaminants, a number of studies were undertaken to accurately quantify discharge from areas downgradient in the regional ground-water flow system from the NTS. This report refines the estimate of ground-water discharge from Oasis Valley. Ground-water discharge from Oasis Valley was estimated by quantifying evapotranspiration (ET), estimating subsurface outflow, and compiling ground-water withdrawal data. ET was quantified by identifying areas of ongoing ground-water ET, delineating areas of ET defined on the basis of similarities in vegetation and soil-moisture conditions, and computing ET rates for each of the delineated areas. A classification technique using spectral-reflectance characteristics determined from satellite imagery acquired in 1992 identified eight unique areas of ground-water ET. These areas encompass about 3,426 acres of sparsely to densely vegetated grassland, shrubland, wetland, and open water. Annual ET rates in Oasis Valley were computed with energy-budget methods using micrometeorological data collected at five sites. ET rates range from 0.6 foot per year in a sparse, dry saltgrass environment to 3.1 feet per year in dense meadow vegetation. Mean annual ET from Oasis Valley is estimated to be about 7,800 acre-feet. Mean annual ground-water discharge by ET from Oasis Valley, determined by removing the annual local precipitation

  18. SURFACE WATER AND GROUND WATER QUALITY MONITORING FOR RESTORATION OF URBAN LAKES IN GREATER HYDERABAD, INDIA

    Science.gov (United States)

    Mohanty, A. K.

    2009-12-01

    SURFACE WATER AND GROUND WATER QUALITY MONITORING FOR RESTORATION OF URBAN LAKES IN GREATER HYDERABAD, INDIA A.K. Mohanty, K. Mahesh Kumar, B. A. Prakash and V.V.S. Gurunadha Rao Ecology and Environment Group National Geophysical Research Institute, (CSIR) Hyderabad - 500 606, India E-mail:atulyakumarmohanty@yahoo.com Abstract: Hyderabad Metropolitan Development Authority has taken up restoration of urban lakes around Hyderabad city under Green Hyderabad Environment Program. Restoration of Mir Alam Tank, Durgamcheruvu, Patel cheruvu, Pedda Cheruvu and Nallacheruvu lakes have been taken up under the second phase. There are of six lakes viz., RKPuramcheruvu, Nadimicheruvu (Safilguda), Bandacheruvu Patelcheruvu, Peddacheruvu, Nallacheruvu, in North East Musi Basin covering 38 sq km. Bimonthly monitoring of lake water quality for BOD, COD, Total Nitrogen, Total phosphorous has been carried out for two hydrological cycles during October 2002- October 2004 in all the five lakes at inlet channels and outlets. The sediments in the lake have been also assessed for nutrient status. The nutrient parameters have been used to assess eutrophic condition through computation of Trophic Status Index, which has indicated that all the above lakes under study are under hyper-eutrophic condition. The hydrogeological, geophysical, water quality and groundwater data base collected in two watersheds covering 4 lakes has been used to construct groundwater flow and mass transport models. The interaction of lake-water with groundwater has been computed for assessing the lake water budget combining with inflow and outflow measurements on streams entering and leaving the lakes. Individual lake water budget has been used for design of appropriate capacity of Sewage Treatment Plants (STPs) on the inlet channels of the lakes for maintaining Full Tank Level (FTL) in each lake. STPs are designed for tertiary treatment i.e. removal of nutrient load viz., Phosphates and Nitrates. Phosphates are

  19. Long-term ground-water monitoring program and performance-evaluation plan for the extraction system at the former Nike Missile Battery Site, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Senus, Michael P.; Tenbus, Frederick J.

    2000-01-01

    This report presents lithologic and ground-water-quality data collected during April and May 2000 in the remote areas of the tidal wetland of West Branch Canal Creek, Aberdeen Proving Ground, Maryland. Contamination of the Canal Creek aquifer with volatile organic compounds has been documented in previous investigations of the area. This study was conducted to investigate areas that were previously inaccessible because of deep mud and shallow water, and to support ongoing investigations of the fate and transport of volatile organic compounds in the Canal Creek aquifer. A unique vibracore drill rig mounted on a hovercraft was used for drilling and ground-water sampling. Continuous cores of the wetland sediment and of the Canal Creek aquifer were collected at five sites. Attempts to sample ground water were made by use of a continuous profiler at 12 sites, without well installation, at a total of 81 depths within the aquifer. Of those 81 attempts, only 34 sampling depths produced enough water to collect samples. Ground-water samples from two sites had the highest concentrations of volatile organic compounds?with total volatile organic compound concentrations in the upper part of the aquifer ranging from about 15,000 to 50,000 micrograms per liter. Ground-water samples from five sites had much lower total volatile organic compound concentrations (95 to 2,100 micrograms per liter), whereas two sites were essentially not contaminated, with total volatile organic compound concentrations less than or equal to 5 micrograms per liter.

  20. A Sediment Transport Model for Sewers

    DEFF Research Database (Denmark)

    Mark, Ole; Larsson, Johan; Larsen, Torben

    1993-01-01

    This paper describes a mathematical model for transport processes in sewers. The model consists of three sub models, a surface model for the description of the buildup and the washoff of sediment particles from the surface area, a morphological model and an advection-dispersion model. The model...

  1. Modeling of radionuclide transport through rock formations and the resulting radiation exposure of reference persons. Calculations using Asse II parameters; Modellierung des Transports von Radionukliden durch Gesteinsschichten und der resultierenden Strahlenexposition von Referenzpersonen. Berechnungen mit Parametern der Asse II

    Energy Technology Data Exchange (ETDEWEB)

    Kueppers, Christian; Ustohalova, Veronika; Steinhoff, Mathias

    2012-05-21

    The long-term release of radioactivity into the ground water path cannot be excluded for the radioactive waste repository Asse II. The possible radiological consequences were analyzed using a radio-ecological scenario developed by GRS. A second scenario was developed considering the solubility of radionuclides in salt saturated solutions and retarding/retention effects during the radionuclide transport through the cap rock layers. The modeling of possible radiation exposure was based on the lifestyle habits of reference persons. In Germany the calculation procedure for the prediction of radionuclide release from final repositories is not defined by national standards, the used procedures are based on analogue methods from other radiation protection calculations.

  2. Chemometric characterisation of the quality of ground waters from different wells in Slovenia

    OpenAIRE

    Novič, Marjana; Vončina, Ernest; Brodnjak-Vončina, Darinka; Sovič, Nataša

    2015-01-01

    The quality of ground water as a source of drinking water in Slovenia is regularly monitored. One of the monitoring programmes is performed on 5 wells for drinking water supply, 3 industrial wells and 2 ground water monitoring wells. Two hundred and fourteen samples of ground waters were analysed in the time 2003-2004. Samples were gathered from ten different sampling sites and physical chemical measurements were performed. The following 13 physical chemical parameters were regularly controll...

  3. Methods and Indicators for Assessment of Regional Ground-Water Conditions in the Southwestern United States

    Science.gov (United States)

    Tillman, Fred D; Leake, Stanley A.; Flynn, Marilyn E.; Cordova, Jeffrey T.; Schonauer, Kurt T.; Dickinson, Jesse E.

    2008-01-01

    Monitoring the status and trends in the availability of the Nation's ground-water supplies is important to scientists, planners, water managers, and the general public. This is especially true in the semiarid to arid southwestern United States where rapid population growth and limited surface-water resources have led to increased use of ground-water supplies and water-level declines of several hundred feet in many aquifers. Individual well observations may only represent aquifer conditions in a limited area, and wells may be screened over single or multiple aquifers, further complicating single-well interpretations. Additionally, changes in ground-water conditions may involve time scales ranging from days to many decades, depending on the timing of recharge, soil and aquifer properties, and depth to the water table. The lack of an easily identifiable ground-water property indicative of current conditions, combined with differing time scales of water-level changes, makes the presentation of ground-water conditions a difficult task, particularly on a regional basis. One approach is to spatially present several indicators of ground-water conditions that address different time scales and attributes of the aquifer systems. This report describes several methods and indicators for presenting differing aspects of ground-water conditions using water-level observations in existing data-sets. The indicators of ground-water conditions developed in this study include areas experiencing water-level decline and water-level rise, recent trends in ground-water levels, and current depth to ground water. The computer programs written to create these indicators of ground-water conditions and display them in an interactive geographic information systems (GIS) format are explained and results illustrated through analyses of ground-water conditions for selected alluvial basins in the Lower Colorado River Basin in Arizona.

  4. Ground-water data for the Beryl-Enterprise area, Escalante Desert, Utah

    Science.gov (United States)

    Mower, R.W.

    1981-01-01

    This report contains a compilation of selected ground-water data for the Beryl-Enterprise area, Iron and Washington Counties, Utah. The records of the wells include such information as driller 's logs, yield, drawdown, use, and temperature of the well water. There are also records of water levels in selected wells for the period 1973-79, chemical analyses of ground water, records of selected springs, and a tabulation of ground-water withdrawals for 1937-78. (USGS)

  5. Mercury migration into ground water, a literature study

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Carden, J.L.; Kury, R.; Eichholz, G.G.

    1994-11-01

    This report presents a broad review of the technical literature dealing with mercury migration in the soil. The approach followed was to identify relevant articles by searching bibliographic data bases, obtaining the promising articles and searching these articles for any additional relevant citations. Eight catagories were used to organize the literature, with a review and summary of each paper. Catagories used were the following: chemical states of mercury under environmental conditions; diffusion of mercury vapor through soil; solubility and stability of mercury in environmental waters; transport of mercury on colloids; models for mercury migration through the environment; analytical techniques; retention of mercury by soil components; formation of organomecurials.

  6. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Canonsburg, Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    This baseline risk assessment evaluates potential impacts to public health and the environment resulting from ground water contamination from past activities at the former uranium processing site in Canonsburg, Pennsylvania. The US Department of Energy Uranium Mill Tailings Remedial Action (UMTRA) Project has placed contaminated material from this site in an on-site disposal cell. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the UMTRA Ground Water Project. Currently, no domestic or drinking water well tap into contaminated ground water of the two distinct ground water units: the unconsolidated materials and the bedrock. Because there is no access, no current health or environmental ri