WorldWideScience

Sample records for judea group aquifer

  1. Salinity sources of Kefar Uriya wells in the Judea Group aquifer of Israel. Part 1—conceptual hydrogeological model

    Science.gov (United States)

    Avisar, D.; Rosenthal, E.; Flexer, A.; Shulman, H.; Ben-Avraham, Z.; Guttman, J.

    2003-01-01

    In the Yarkon-Taninim groundwater basin, the karstic Judea Group aquifer contains groundwater of high quality. However, in the western wells of the Kefar Uriya area located in the foothills of the Judea Mountains, brackish groundwater was locally encountered. The salinity of this water is caused presumably by two end members designated as the 'Hazerim' and 'Lakhish' water types. The Hazerim type represents surface water percolating through a highly fractured thin chalky limestone formation overlying the Judea Group aquifer. The salinity of the water derives conjointly from several sources such as leachates from rendzina and grumosols, dissolution of caliche crusts which contain evaporites and of rock debris from the surrounding formations. This surface water percolates downwards into the aquifer through a funnel- or chimney-like mechanism. This local salinization mechanism supercedes another regional process caused by the Lakhish waters. These are essentially diluted brines originating from deep formations in the western parts of the Coastal Plain. The study results show that salinization is not caused by the thick chalky beds of the Senonian Mt Scopus Group overlying the Judea Group aquifer, as traditionally considered but prevalently by aqueous leachates from soils and rock debris. The conceptual qualitative hydrogeological model of the salinization as demonstrated in this study, is supported by a quantitative hydrological model presented in another paper in this volume.

  2. The fault pattern in the northern Negev and southern Coastal Plain of Israel and its hydrogeological implications for groundwater flow in the Judea Group aquifer

    Science.gov (United States)

    Weinberger, G.; Rosenthal, E.

    1994-03-01

    On the basis of a broadly expanding data base, the hydrogeological properties of the Judea Group sequence in the northern Negev and southern Coastal Plain of Israel have been reassessed. The updated subsurface model is based on data derived from water- and oil-wells and on recent large-scale geophysical investigations. A new regional pattern of the reassessed geological through the subsurface of the study area has been revealed. In view of the reassessed geological and hydrological subsurface setting, it appears that the Judea Group aquifer should not be regarded as one continuous and undisturbed hydrological unit; owing to the occurrence of regional faults, its subaquifers are locally interconnected. These subaquifers, which contain mainly high-quality water, are juxtaposed, as a result of faulting, against Kurnub Group sandstones containing brackish paleowater. The latter Group is faulted against late Jurassic formations containing highly saline groundwater. In the Beer Sheva area, the Judea Group aquifer is vertically displaced against the Senonian and Eocene Mt. Scopus and Avdat Groups, which also contain brackish and saline water. In the southern Coastal Plain, major faults locally dissect also the Pleistocene Kurkar Group, facilitating inflow of Mg-rich groundwater deriving from Judea Group dolomites. The new geological evidence and its hydrogeological implications provide new solutions for previously unexplained salinization phenomena.

  3. Transition from confined to phreatic conditions as the factor controlling salinization and change in redox state, Upper subaquifer of the Judea Group, Israel

    Science.gov (United States)

    Gavrieli, Ittai; Burg, Avi; Guttman, Joseph

    2002-08-01

    An increase in salinity and change from oxic to anoxic conditions are observed in the Upper subaquifer of the Judea Group in the Kefar Uriyya pumping field at the western foothills of the Judea Mountains, Israel. Hydrogeological data indicate that the change, which occurs over a distance of only a few kilometers, coincides with a transition from confined to phreatic conditions in the aquifer. The deterioration in the water quality is explained as a result of seepage of more saline, organic-rich water from above, into the phreatic "roofed" part of the aquifer. The latter is derived from the bituminous chalky rocks of the Mount Scopus Group, which confine the aquifer in its southeastern part. In this confined part, water in perched horizons within the Mount Scopus Group cannot leak down and flow westward while leaching organic matter and accumulating salts. However, upon reaching the transition area from confined to phreatic conditions, seepage to the Judea Upper subaquifer is possible, thereby allowing it to be defined as a leaky aquifer. The incoming organic matter consumes the dissolved oxygen and allows bacterial sulfate reduction. The latter accounts for the H2S in the aquifer, as indicated by sulfur isotopic analyses of coexisting sulfate and sulfide. Thus, from an aquifer management point of view, in order to maintain the high quality of the water in the confined southeastern part of the Kefar Uriyya field, care should be taken not to draw the confined-roofed transition area further east by over pumping.

  4. HERODIAN JUDEA: GAMES, POLITICS, KINGSHIP

    Directory of Open Access Journals (Sweden)

    Cody Scott Ames

    2015-06-01

    Full Text Available This article will detail the kingship of Herod the Great in Judea and his enrollment of Greco-Roman architecture and culture during his reign in the first century BCE.  Herod, it seems, made a deliberate break from his Jewish kingdom for the electrifying ways of the Greco-Roman world.  Herodian Judea faced many changes over its history, but none more drastic in terms of architecture and culture than during his reign amidst the Roman domination in Judea, a period that begins with Pompey the Great in 63 BCE and ends with the Muslim invasion in the 650’s CE (Herod died in 4 BCE.  Herod the Great is widely regarded as both a Roman sympathizer (OGIS 414 and a promoter of Greco-Roman culture (Roller 1998; Smallwood 1981.  He is believed to have underwritten the construction of monumental buildings including harbors, temples, and arches as well as theaters and amphitheaters (Josephus AJ 15.421.  These architectural endeavors, which bear strong Greco-Roman cultural significances, suggest Herod may have been influenced by Greek designs which were filtered through Roman culture (Smallwood 1981; Geiger 2005.                               The aims of this article are twofold: 1 to offer an explanation for Herod’s adoption of Greco-Roman architecture and Greco-Roman games; and 2 to better understand the socio-political crafting of Herod’s kingship. To this end, I will look into possible relationships between Herod, the Roman aristocracy and Jewish norms as documented by ancient accounts.  I will also examine the physical remains of Herod’s building program in Caesarea Maritima.             Our journey will begin with Herod’s three trips to Rome in the years 40, 17-16 and 13-12 BCE in an effort to attain the crown and bring stability back to Judea as detailed by accounts of Josephus (Josephus Ant. 15.342-3.  It also will discuss select architectural remains from Herod’s building program at Caesarea

  5. Aquifers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands, portrayed as polygons....

  6. Aquifers

    Data.gov (United States)

    Department of Homeland Security — This map layer contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands, portrayed as polygons....

  7. Medicinal plants growing in the Judea region: network approach for searching potential therapeutic targets

    Directory of Open Access Journals (Sweden)

    Arie Budovsky

    2012-09-01

    Full Text Available Plants growing in the Judea region are widely used in traditional medicine of the Levant region. Nevertheless, they have not so far been sufficiently analyzed and their medicinal potential has not been evaluated. This study is the first attempt to fill the gap in the knowledge of the plants growing in the region. Comprehensive data mining of online botanical databases and peer-reviewed scientific literature including ethno-pharmacological surveys from the Levant region was applied to compile a full list of plants growing in the Judea region, with the focus on their medicinal applications. Around 1300 plants growing in the Judea region were identified. Of them, 25% have medicinal applications which were analyzed in this study. Screening for chemical-protein interactions, together with the network-based analysis of potential targets, will facilitate discovery and therapeutic applications of the Judea region plants. Such an approach could also be applied as an integrative platform for further searching the potential therapeutic targets of plants growing in other regions of the world.

  8. A Columbia River Basalt Group Aquifer in Sustained Drought: Insight from Geophysical Methods

    Directory of Open Access Journals (Sweden)

    Mark W. Piersol

    2015-07-01

    Full Text Available Aquifers within the Columbia River Basalt Group (CRBG provide a critical water supply throughout much of the Pacific Northwest of the United States. Increased pumping has resulted in water level declines in this region. Recharge into this aquifer system is generally not well understood. Recent suggestions of probable decades-long droughts in the 21st century add to this problem. We show that geophysical methods can provide useful parameters for improved modeling of aquifers in a primary CRBG aquifer located on the eastern edge of the Columbia Plateau. Groundwater models depend in part on the area, thickness, porosity, storativity, and nature of confinement of this aquifer, most of which are poorly constrained by existing well information and previous stress tests. We have made use of surface gravity measurements, borehole gravity measurements, barometric efficiency estimates, earth tidal response, and earthquake seismology observations to constrain these parameters. We show that the aquifer, despite its persistent drawdown, receives a great deal of recharge annually. Much of the recharge to the aquifer is due to leakage from overlying flows, ultimately tied to precipitation, an important result for future aquifer management in times of sustained drought.

  9. Geochemistry of Paleokarst Aquifers of the Knox Group in Tennessee and Kentucky

    Science.gov (United States)

    Bradley, Michael W.; Parris, Thomas

    2014-01-01

    Water-quality samples were collected from deep carbonate formations in the Cambrian- and Ordovician-age Knox Group in the central areas of Kentucky and Tennessee as part of an evaluation of the formations for carbon sequestration (Kentucky) and the geohydrology of the paleokarst aquifers (Tennessee). Geochemical data from the deep carbonate formations have been used to evaluate the chemical evolution of the groundwater, residence time, and the degree of confinement. The geochemical data indicate differences in groundwater evolution in the different structural settings including the Nashville Dome, Cincinnati Arch, and Illinois Basin (fig. 1).

  10. Fractured-aquifer hydrogeology from geophysical logs: Brunswick group and Lockatong Formation, Pennsylvania

    Science.gov (United States)

    Morin, Roger H.; Senior, Lisa A.; Decker, Edward R.

    2000-01-01

    The Brunswick Group and the underlying Lockatong Formation are composed of lithified Mesozoic sediments that constitute part of the Newark Basin in southeastern Pennsylvania. These fractured rocks form an important regional aquifer that consists of gradational sequences of shale, siltstone, and sandstone, with fluid transport occurring primarily in fractures. An extensive suite of geophysical logs was obtained in seven wells located at the borough of Lansdale, Pennsylvania, in order to better characterize the areal hydrogeologic system and provide guidelines for the refinement of numerical ground water models. Six of the seven wells are approximately 120 m deep and the seventh extends to a depth of 335 m. Temperature, fluid conductivity, and flowmeter logs are used to locate zones of fluid exchange and to quantify transmissivities. Electrical resistivity and natural gamma logs together yield detailed stratigraphic information, and digital acoustic televiewer data provide magnetically oriented images of the borehole wall from which almost 900 fractures are identified.Analyses of the geophysical data indicate that the aquifer penetrated by the deep well can be separated into two distinct structural domains, which may, in turn, reflect different mechanical responses to basin extension by different sedimentary units:1. In the shallow zone (above 125 m), the dominant fracture population consists of gently dipping bedding plane partings that strike N46°E and dip to the northwest at about 11 degrees. Fluid flow is concentrated in the upper 80 m along these subhorizontal fractures, with transmissivities rapidly diminishing in magnitude with depth.2. The zone below 125 m marks the appearance of numerous high-angle fractures that are orthogonal to the bedding planes, striking parallel but dipping steeply southeast at 77 degrees.This secondary set of fractures is associated with a fairly thick (approximately 60 m) high-resistivity, low-transmissivity sandstone unit that is

  11. The diagnostic plot analysis of artesian aquifers with case studies in Table Mountain Group of South Africa

    Science.gov (United States)

    Sun, Xiaobin; Xu, Yongxin; Lin, Lixiang

    2015-05-01

    Parameter estimates of artesian aquifers where piezometric head is above ground level are largely made through free-flowing and recovery tests. The straight-line method proposed by Jacob-Lohman is often used for interpretation of flow rate measured at flowing artesian boreholes. However, the approach fails to interpret the free-flowing test data from two artesian boreholes in the fractured-rock aquifer in Table Mountain Group (TMG) of South Africa. The diagnostic plot method using the reciprocal rate derivative is adapted to evaluate the artesian aquifer properties. The variation of the derivative helps not only identify flow regimes and discern the boundary conditions, but also facilitates conceptualization of the aquifer system and selection of an appropriate model for data interpretation later on. Test data from two free-flowing tests conducted in different sites in TMG are analysed using the diagnostic plot method. Based on the results, conceptual models and appropriate approaches are developed to evaluate the aquifer properties. The advantages and limitations of using the diagnostic plot method on free-flowing test data are discussed.

  12. Time scale for degradation and erosion of archaeological terraces in the Judea Mountains, Israel

    Science.gov (United States)

    Porat, Naomi; Elinson, Rotem; Ben Dor, Eyal; Avni, Yoav; Gadot, Yuval

    2017-04-01

    The fate of mountain bench terraces which have been abandoned in ancient times is puzzling. On the one hand recently abandoned terraces undergo rapid degradation by walls crumbling, leading to soil being washed by rain water out of breaches in the walls, suggesting that within a short time all soil would be washed down-slope. On the other hand slopes with degraded terraces appear to still retain much soil even though only faint remains of the terraces exist. Moreover, if soil is rapidly eroded down-slope when terraces are no longer maintained, where do subsequent terrace builders find the soil to fill behind the stone walls? These questions were addressed as part of a larger study on the chronology of terraces in the Judea Mountains, Israel. Previous OSL dating of terrace soils in the region showed that the majority of the maintained terraces were constructed during the past 700 years, and only occasionally older ages were obtained for the soil at the very base of these terraces. Concerns were raised that soil erosion caused earlier events of terrace construction to disappear. To check if terraces and soils indeed erode entirely and how long this might take, we selected a relatively smooth hill slope showing small patches of limestone bedrock as well as remains of highly degraded sets of terraces. Three pits were excavated in soils within three different terrace remains down to bedrock, some to a depth of 2 m, and samples for OSL dating were collected from the exposed soil sections. In all three pits the lowermost samples gave ages of 3000-4500 years before the present, possibly the natural soils before any human intervention. However samples from a depth of 35-45 cm gave ages of 350-200 years, providing the last time the soil at that depth was exposed to sunlight. This suggests that the terraces were abandoned in the past 200 years or so and since then degraded. However the thick soil present on most of the slope suggests that after the first stage of rapid

  13. Who Are Students of Physical Therapy? A Case Study: The Academic College of Judea and Samaria and the Ben Gurion University

    Science.gov (United States)

    Davidovitch, Nitza; Danziger, Yosefa

    2006-01-01

    This study focuses on the attributes of students of Physical Therapy, and compares the profiles of students of Physical Therapy in two institutions of higher learning in Israel, Ben Gurion University (BGU) and the Academic College of Judea and Samaria (ACJS), Israel's largest public academic college. This study focuses on this department, where…

  14. Alluvial Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — This coverage shows the extents of the alluvial aquifers in Kansas. The alluvial aquifers consist of unconsolidated Quaternary alluvium and contiguous terrace...

  15. Carbonate aquifers

    Science.gov (United States)

    Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen

    2012-01-01

    Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

  16. Life of the Aquifer: Improving Earth Science Education for Teachers and Students in High Schools of Under-represented Groups on the North Carolina Coastal Plain

    Science.gov (United States)

    Farley, M. B.; Phillips, P. L.; McBroom, R.

    2007-12-01

    Life of the Aquifer is a program to improve Earth Science education in local public high schools. Geologic awareness among the local population is low because southeastern N.C. are on the Coastal Plain where rocks are not visible. This has made instruction in Earth Science, now required in North Carolina high schools, difficult. Our approach is to use groundwater, source of local public water, as a theme to organize instruction in geology. More than 70% of the student population in Robeson County, a rural low-wealth area, is from groups under- represented in the geosciences (46% Native American and 31% African American). Linking basic concepts in geology to groundwater is a way to show how geology is real and affects society. Our project engages teachers and students in active inquiry of the functioning of local aquifers from recharge to groundwater production. Although data on water levels in the Black Creek aquifer have been collected, there has been little formal investigation because serious problems with groundwater have not been noted to date. Nonetheless, the hydraulic head of Black Creek Aquifer wells has been declining. We started by improving skills of local Earth Science teachers, because most have had no formal education in geology. The teachers attended workshops on basic geology, groundwater, and exercises based on local groundwater data. The workshops also included field trips to outcrops exposing the local aquifer, 100 km away in South Carolina. We also showed teachers how each topic addresses Competency Goals in the Standard Course of Study. By using our instructional modules, the teachers assist their students to develop spatial reasoning skills by analyzing maps. Student geologic knowledge is increased by learning how the components of a groundwater system form as a result of geologic processes and collecting data from the Internet on changes in groundwater systems over time. Our remaining implementation activity is installation of wells to

  17. Estimated 2008 groundwater potentiometric surface and predevelopment to 2008 water-level change in the Santa Fe Group aquifer system in the Albuquerque area, central New Mexico

    Science.gov (United States)

    Falk, Sarah E.; Bexfield, Laura M.; Anderholm, Scott K.

    2011-01-01

    The water-supply requirements of the Albuquerque metropolitan area of central New Mexico have historically been met almost exclusively by groundwater withdrawal from the Santa Fe Group aquifer system. Previous studies have indicated that the large quantity of groundwater withdrawal relative to recharge has resulted in water-level declines in the aquifer system throughout the metropolitan area. Analysis of the magnitude and pattern of water-level change can help improve understanding of how the groundwater system responds to withdrawals and variations in the management of the water supply and can support water-management agencies' efforts to minimize future water-level declines and improve sustainability. This report, prepared by the U.S. Geological Survey in cooperation with the Albuquerque Bernalillo County Water Utility Authority, presents the estimated groundwater potentiometric surface during winter (from December to March) of the 2008 water year and the estimated changes in water levels between predevelopment and water year 2008 for the production zone of the Santa Fe Group aquifer system in the Albuquerque and surrounding metropolitan and military areas. Hydrographs from selected wells are included to provide details of historical water-level changes. In general, water-level measurements used for this report were measured in small-diameter observation wells screened over short intervals and were considered to best represent the potentiometric head in the production zone-the interval of the aquifer, about 300 feet below land surface to 1,100 feet or more below land surface, in which production wells generally are screened. Water-level measurements were collected by various local and Federal agencies. The 2008 water year potentiometric surface map was created in a geographic information system, and the change in water-level elevation from predevelopment to water year 2008 was calculated. The 2008 water-level contours indicate that the general direction of

  18. Simulated three-dimensional ground-water flow in the Lockport Group, a fractured-dolomite aquifer near Niagara Falls, New York

    Science.gov (United States)

    Yager, Richard M.

    1996-01-01

    A three-dimensional model was developed through a parameter-estimation method based on nonlinear regression to simulate ground-water flow in the Lockport Group, a fractured dolomite aquifer near Niagara Falls, N.Y. Horizontal fracture zones within the Lockport Group were represented by model layers, and connections between the zones were represented by vertical leakage between the layers. Results of steady-state simulations were compared with (1) the observed potentiometric surface of the weathered bedrock surface, (2) average heads measured by piezometers in underlying fracture zones, (3) low-flow measurements of springs and streams, and (4) measurements of discharge from tunnels and excavations. Results indicated that (1) measured flow into the Falls Street tunnel, an unlined storm sewer excavated in bedrock, exceeds the amount that can be sustained by the aquifer, and, therefore, a connection between the tunnel and the Niagara River can be assumed; (2) recharge within the urban parts of the modeled area is greater than in rural areas, possibly because of losses from the municipal water supply or infiltration from unlined storm sewers that intersect the bedrock; and (3) lowlands near the Niagara River might contain widespread areas of upward flow that discharge ground water through evapotranspiration and surface drainage.

  19. Estimated 2012 groundwater potentiometric surface and drawdown from predevelopment to 2012 in the Santa Fe Group aquifer system in the Albuquerque metropolitan area, central New Mexico

    Science.gov (United States)

    Powell, Rachel I.; McKean, Sarah E.

    2014-01-01

    Historically, the water-supply requirements of the Albuquerque metropolitan area of central New Mexico were met almost exclusively by groundwater withdrawal from the Santa Fe Group aquifer system. In response to water-level declines, the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) began diverting water from the San Juan-Chama Drinking Water Project in December 2008 to reduce the use of groundwater to meet municipal demand. Modifications in the demand for water and the source of the supply of water for the Albuquerque metropolitan area have resulted in a variable response in the potentiometric surface of the production zone (the interval of the aquifer, from within about 200 feet below the water table to 900 feet or more, in which supply wells generally are screened) of the Santa Fe Group aquifer system. Analysis of the magnitude and spatial distribution of water-level change can help improve the understanding of how the groundwater system responds to withdrawals and variations in the management of the water supply and can support water-management agencies’ efforts to minimize future water-level declines and improve sustainability. The U.S. Geological Survey (USGS), in cooperation with the ABCWUA, has developed an estimate of the 2012 potentiometric surface of the production zone of the Santa Fe Group aquifer system in the Albuquerque metropolitan area. This potentiometric surface is the latest in a series of reports depicting the potentiometric surface of the area. This report presents the estimated potentiometric surface during winter (from December to March) of water year 2012 and the estimated changes in potentiometric surface between predevelopment (pre-1961) and water year 2012 for the production zone of the Santa Fe Group aquifer system in the Albuquerque metropolitan area. Hydrographs from selected piezometers are included to provide details of historical water-level changes. In general, water-level measurements used for this report were

  20. Ozark Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — These digital maps contain information on the altitude of the base and top, the extent, and the potentiometric surface of the Ozark aquifer in Kansas. The Ozark...

  1. Stable isotope and noble gas constraints on the source and residence time of spring water from the Table Mountain Group Aquifer, Paarl, South Africa and implications for large scale abstraction

    Science.gov (United States)

    Miller, J. A.; Dunford, A. J.; Swana, K. A.; Palcsu, L.; Butler, M.; Clarke, C. E.

    2017-08-01

    Large scale groundwater abstraction is increasingly being used to support large urban centres especially in areas of low rainfall but presents particular challenges in the management and sustainability of the groundwater system. The Table Mountain Group (TMG) Aquifer is one of the largest and most important aquifer systems in South Africa and is currently being considered as an alternative source of potable water for the City of Cape Town, a metropolis of over four million people. The TMG aquifer is a fractured rock aquifer hosted primarily in super mature sandstones, quartzites and quartz arenites. The groundwater naturally emanates from numerous springs throughout the cape region. One set of springs were examined to assess the source and residence time of the spring water. Oxygen and hydrogen isotopes indicate that the spring water has not been subject to evaporation and in combination with Na/Cl ratios implies that recharge to the spring systems is via coastal precipitation. Although rainfall in the Cape is usually modelled on orographic rainfall, δ18O and δ2H values of some rainfall samples are strongly positive indicating a stratiform component as well. Comparing the spring water δ18O and δ2H values with that of local rainfall, indicates that the springs are likely derived from continuous bulk recharge over the immediate hinterland to the springs and not through large and/or heavy downpours. Noble gas concentrations, combined with tritium and radiocarbon activities indicate that the residence time of the TMG groundwater in this area is decadal in age with a probable maximum upper limit of ∼40 years. This residence time is probably a reflection of the slow flow rate through the fractured rock aquifer and hence indicates that the interconnectedness of the fractures is the most important factor controlling groundwater flow. The short residence time of the groundwater suggest that recharge to the springs and the Table Mountain Group Aquifer as a whole is

  2. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Science.gov (United States)

    Becker, C.J.; Runkle, D.L.; Rea, Alan

    1997-01-01

    ARC/INFO export and nonproprietary format files The data sets in this report include digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer covers approximately 82 square miles and supplies water for irrigation, domestic, municipal, and industrial use for the City of Enid and western Garfield County. The Quaternary-age Enid isolated terrace aquifer is composed of terrace deposits that consist of discontinuous layers of clay, sandy clay, sand, and gravel. The aquifer is unconfined and is bounded by the underlying Permian-age Hennessey Group on the east and the Cedar Hills Sandstone Formation of the Permian-age El Reno Group on the west. The Cedar Hills Sandstone Formation fills a channel beneath the thickest section of the Enid isolated terrace aquifer in the midwestern part of the aquifer. All of the data sets were digitized and created from information and maps in a ground-water modeling thesis and report of the Enid isolated terrace aquifer. The maps digitized were published at a scale of 1:62,500. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  3. Escorrentía y erosión a lo largo de un gradiente climático-altitudinal efecto por el pastoreo en el desierto de Judea

    Directory of Open Access Journals (Sweden)

    Artemi Cerdà

    1999-01-01

    Full Text Available Los suelos del Desierto de Judea generan rápidos encharcamientos y abundantes escorrentías, lo que es debido a las ínfimas tasas de infiltración y a curvas de escorrentía de gran pendiente que alcanzan súbitamente las tasas máximas ante chaparrones simulados de 50,36 mm h-1 de intensidad y 45 minutos de duración.Se ha comprobado que el clima determina las características de los suelos y el comportamiento de los procesos geomorfológicos. A lo largo del gradiente climático estudiado las tasas de infiltración decrecen con la precipitación, mientras que las escorrentías, la salinidad de éstas y las pérdidas de suelo aumentan. Además del clima, el uso antrópico influye drásticamente en la respuesta del suelo ante la lluvia. Así, la influencia del clima se ve alterada por el sobrepastoreo, ya que éste modifica la composición florística, la cubierta vegetal y las costras superficiales, con lo que se favorece la erosión del suelo.

  4. Potentiometric surfaces and water-level trends in the Cockfield (upper Claiborne) aquifer in southern Arkansas and the Wilcox (lower Wilcox) aquifer of northeastern and southern Arkansas, 2012

    Science.gov (United States)

    Rodgers, Kirk D.

    2015-01-01

    The Cockfield aquifer, located in southern Arkansas, is composed of Eocene-age sand beds found near the base of the Cockfield Formation of Claiborne Group. The Wilcox aquifer, located in northeastern and southern Arkansas, is composed of Paleocene-age sand beds found in the middle to lower part of the Wilcox Group. The Cockfield and Wilcox aquifers are primary sources of groundwater. In 2010, withdrawals from the Cockfield aquifer in Arkansas totaled 19.2 million gallons per day (Mgal/d), and withdrawals from the Wilcox aquifer totaled 36.5 Mgal/d.

  5. EPA Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Information on sole source aquifers (SSAs) is widely used in assessments under the National Environmental Policy Act and at the state and local level. A national...

  6. Lower Cretaceous aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Lower Cretaceous aquifers in the states of Montana, Wyoming, South Dakota, Kansas, Nebraska, Iowa, and Minnesota..

  7. Hydraulic Tomography to Characterization of Heterogeneity of Unconfined Aquifers

    Science.gov (United States)

    Zhu, J.; Yeh, T. J.

    2008-12-01

    Analytical models are the most widely used methods for analyzing pumping tests in unconfined aquifers. However, one major group analytical models assume instantaneous and complete drainage at the water table and therefore are inadequate to account for gradual drainage of water from the vadose zone due to pumping; the other major group analytical models use an exponential function of drawdown at the water table to account for gradual drainage and are subsequently limited to represent the highly non-linear flow in the vadose zone. Moreover, both models assume aquifer homogeneity while the natural aquifers are inherently heterogeneous. Recently emerged Hydraulic tomography (HT) is a cost-effective method for mapping spatial distribution of aquifer hydraulic properties. HT takes advantage of the power of numerical models and fuses information from multiple cross-hole tests conducted at different locations to image aquifers in great details. In this study, we apply HT concept to unconfined aquifers. To accurately simulate the flow behavior due to a HT survey in an unconfined aquifer, a fully three dimensional variably saturated flow model based on mixed form of Richards equation is used. Pressure responses in both saturated and unsaturated zones are used to estimate spatial variations of hydraulic conductivity, specific storage, and soil water constitutive model parameters through a sequential successive linear estimator. A systematic approach that uses wavelet analysis, least-square method, and fuzzy similarity compassion is applied for data denoising, statistic inputs, convergence, and performance assessment. A cross-correlation is also performed to investigate the relation between pressure change and different parameters. The HT method for unconfined aquifers is tested in a synthetic aquifer. The tests show that the proposed HT method effectively maps heterogeneity of the unconfined aquifer and predicts the vadose zone responses due to a pumping test more accurately

  8. Inquiry and Aquifers.

    Science.gov (United States)

    Leuenberger, Ted; Shepardson, Daniel; Harbor, Jon; Bell, Cheryl; Meyer, Jason; Klagges, Hope; Burgess, Willie

    2001-01-01

    Presents inquiry-oriented activities that acquaint students with groundwater sources, movement of water through aquifers, and contamination of groundwater by pollution. In one activity, students use well log data from web-based resources to explore groundwater systems. Provides sample well log data for those not having access to local information.…

  9. Inquiry and Aquifers.

    Science.gov (United States)

    Leuenberger, Ted; Shepardson, Daniel; Harbor, Jon; Bell, Cheryl; Meyer, Jason; Klagges, Hope; Burgess, Willie

    2001-01-01

    Presents inquiry-oriented activities that acquaint students with groundwater sources, movement of water through aquifers, and contamination of groundwater by pollution. In one activity, students use well log data from web-based resources to explore groundwater systems. Provides sample well log data for those not having access to local information.…

  10. Estimation of hydraulic characteristics in the Santa Fe Group aquifer system using computer simulations of river and drain pulses in the Rio Bravo study area, near Albuquerque, New Mexico

    Science.gov (United States)

    Roark, D.M.

    2001-01-01

    In 1997, the U.S. Geological Survey conducted a hydrologic investigation of the surface-water/ground-water interaction of the Rio Grande and the surrounding alluvium and the Santa Fe Group aquifer system in an area near the Rio Bravo Bridge, south of Albu- querque, New Mexico. A set of existing wells and new wells were instrumented to monitor water levels in a section perpendicular to the Rio Grande on the east side of the river. Equipment to measure stream stage was installed at two sites--on the Albuquerque Riverside Drain and on the Rio Grande. A short-duration river pulse and a long-duration river pulse were used to stress the ground-water system while the changes in water levels were monitored. A ground- water flow-model simulation using the principle of superposition was used to estimate the hydraulic characteristics of the local ground-water system. Simulated horizontal hydraulic conductivities varied from 0.03 to 100 feet per day, and vertical hydraulic conductivities varied from 1.5 x 10-6 to 0.01 foot per day. The specific yield of layer 1 was estimated to be 0.3. Specific storage for layers 2 through 11 was 1.0 x 10-6. Water entering the model from the river along a 300-foot-wide cross section during simulation of the short-duration pulse averaged 7.46 x 10-3 cubic foot per second and during the long-duration pulse was 1.66 x 10-3 cubic foot per second. The average flux from the model to the drain during the short-duration pulse was 3.18 x 10-3 cubic foot per second. The average flux for the long-duration pulse was 7.14 x 10-3 cubic foot per second from the drain to the model.

  11. Investigations of Liquid Water Retention in the Greenland Firn Aquifer

    Science.gov (United States)

    Forster, R. R.; Miège, C.; Solomon, D. K.; Koenig, L.; Miller, O. L.; Schmerr, N. C.; Montgomery, L. N.

    2015-12-01

    Liquid water is retained year-round within the Greenland firn aquifer in the subsurface pore space predominantly in the southeast region of the ice sheet where accumulation and melt rates are high. Our group uses a combination of remote sensing methods and field-based measurements to investigate the aquifer near Helheim Glacier. We map the current spatial extent of the aquifer system from airborne radar measurements on board NASA's Operation IceBridge (OIB) developed at the University of Kansas's Center for Remote Sensing of the Ice Sheets (CReSIS). Ground-based measurements from five field campaigns (2011, 2013, 2014, and two in 2015) are used to investigate the depth, thickness, and volume of water, hydraulic properties of the aquifer system, water saturation concentrations, residence time of the water, and the flow within the aquifer. Techniques include ground penetrating radar, seismic refraction, nuclear magnetic resonance sounding, pumping tests, and environmental tracer measurements. We also model the potential of aquifer discharge into a crevasse to initiate a fracture to the bed of the ice sheet. These types of investigations are needed to understand the aquifers influence on the ice sheet's mass balance.

  12. EPA Region 1 Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — This coverage contains boundaries of EPA-approved sole source aquifers. Sole source aquifers are defined as an aquifer designated as the sole or principal source of...

  13. Sole Source Aquifers for NY and NJ

    Data.gov (United States)

    U.S. Environmental Protection Agency — This layer is the designated sole source aquifers of New York and New Jersey. A Sole Source Aquifer, is an aquifer that supplies 50% or more of the drinking water...

  14. Hydraulic conductivities of fractures and matrix in Slovenian carbonate aquifers

    Directory of Open Access Journals (Sweden)

    Timotej Verbovšek

    2008-12-01

    Full Text Available Hydraulic conductivities and specific storage coefficients of fractures and matrix in Slovenian carbonate aquifers were determined by Barker’s method for pumping test analysis, based on fractional flow dimension. Values are presented for limestones and mainly for dolomites, and additionally for separate aquifers, divided by age andlithology in several groups. Data was obtained from hydrogeological reports for 397 water wells, and among these, 79 pumping tests were reinterpreted. Hydraulic conductivities of fractures are higher than the hydraulic conductivities of matrix, and the differences are highly statistically significant. Likewise, differences are significant for specific storage, and the values of these coefficients are higher in the matrix. Values of all coefficients vary in separate aquifers, and the differences can be explained by diagenetic effects, crystal size, degree of fracturing, andcarbonate purity. Comparison of the methods, used in the reports, and the Barker’s method (being more suitable for karstic and fractured aquifers, shows that the latter fits real data better.

  15. High Temperature Aquifer Storage

    Science.gov (United States)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2016-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. Apart from high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. An enormous technical challenge is the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10 - 50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye, into a depth of about 300 m b.s.l. resp. 470 m b.s.l. Injection and production rates were 15 L/s. To achieve the desired water temperatures, about 4 TJ of heat energy were necessary. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for analysing the concentration of the dyes and the major cations at sampling intervals of down to 15 minutes. Additional water samples were taken and analysed in the laboratory. The disassembled heat exchanger prooved that precipitation was successfully prevented by adding CO2 to the water before heating. Nevertheless, hydrochemical data proved both, dissolution and precipitation processes in the aquifer. This was also suggested by the hydrochemical modelling with PhreeqC and is traced back to mixture dissolution and changing

  16. Specific yield, High Plains aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents specific-yield ranges in the High Plains aquifer of the United States. The High Plains aquifer underlies 112.6 million acres (176,000...

  17. Denitrification in a deep basalt aquifer: implications for aquifer storage and recovery.

    Science.gov (United States)

    Nelson, Dennis; Melady, Jason

    2014-01-01

    Aquifer storage and recovery (ASR) can provide a means of storing water for irrigation in agricultural areas where water availability is limited. A concern, however, is that the injected water may lead to a degradation of groundwater quality. In many agricultural areas, nitrate is a limiting factor. In the Umatilla Basin in north central Oregon, shallow alluvial groundwater with elevated nitrate-nitrogen of 9 mg/L is injected into the Columbia River Basalt Group (CRBG), a transmissive confined aquifer(s) with low natural recharge rates. Once recovery of the injected water begins, however, NO3 -N in the recovered water decreases quickly to storage. In contrast to NO3 -N, other constituents in the recovered water show little variation, inconsistent with migration or simple mixing as an explanation of the NO3 -N decrease. Nitrogen isotopic ratios (δ(15) N) increase markedly, ranging from +3.5 to > +50, and correlate inversely with NO3 -N concentrations. This variation occurs in recovery of aquifer, averaging 3.0 mg/L. Similar to nitrate concentrations, TOC drops in the recovered water, consistent with this component contributing to the denitrification of nitrate during storage.

  18. Bedrock aquifers of eastern San Juan County, Utah

    Science.gov (United States)

    Avery, Charles

    1986-01-01

    This study is one of a series of studies appraising the waterbearing properties of the Navajo Sandstone and associated formations in southern Utah.  The study area is about 4,600 square miles, extending from the Utah-Arizona State line northward to the San Juan-Grand County line and westward from the Utah-Colorado State line to the longitude of about 109°50'.Some of the water-yielding formations are grouped into aquifer systems. The C aquifer is comprised of the DeChelly Sandstone Member of the Cutler Formation.  The P aquifer is comprised of the Cedar Mesa Member of the Cutler Formation and the undifferentiated Cutler Formation. The N aquifer is comprised of the sedimentary section that includes the Wingate Sandstone, Kayenta Formation, Navajo Sandstone, Carmel Formation, and Entrada sandstone.  The M aquifer is comprised of the Bluff Sandstone Member and other sandstone units of the Morrison Formation.  The D aquifer is comprised of the Burro Canyon Formation and Dakota Sandstone.  Discharge from the ground-water reservoir to the San Juan River between gaging stations at Four Corners and Mexican Hat is about 66 cubic feet per second.The N aquifer is the main aquifer in the study area. Recharge by infiltration of precipitation is estimated to be 25,000 acre-feet per year.  A major ground-water divide exists under the broad area east of Monticello.  The thickness of the N aquifer, where the sedimentary section is fully preserved and saturated, generally is 750 to 1,250 feet.   Hydraulic conductivity values obtained from aquifer tests range from 0.02 to 0.34 foot per day.  The total volume of water in transient storage is about 11 million acre-feet. Well discharge somewhat exceeded 2,340 acre-feet during 1981.  Discharge to the San Juan River from the N aquifer is estimated to be 6.9 cubic feet per second. Water quality ranges from a calcium bicarbonate to sodium chloride type water

  19. Hydrogeology and Aquifer Storage and Recovery Performance in the Upper Floridan Aquifer, Southern Florida

    Science.gov (United States)

    Reese, Ronald S.; Alvarez-Zarikian, Carlos A.

    2007-01-01

    between flow zones is better in southwestern Florida than in southeastern Florida. Vertical hydraulic conductivity in the upper part of the aquifer also may be higher in southeastern Florida because of unconformities present at formation contacts within the aquifer that may be better developed in this area. Recovery efficiencies per cycle varied widely. Eight sites had recovery efficiencies of less than about 10 percent for the first cycle, and three of these sites had not yet achieved recoveries exceeding 10 percent, even after three to five cycles. The highest recovery efficiency achieved per cycle was 94 percent. Three southeastern coastal sites and two southwestern coastal sites have achieved potable water recoveries per cycle exceeding 60 percent. One of the southeastern coastal sites and both of the southwestern coastal sites achieved good recoveries, even with long storage periods (from 174 to 191 days). The high recovery efficiencies for some cycles apparently resulted from water banking?an operational approach whereby an initial cycle with a large recharge volume of water is followed by cycles with much smaller recharge volume. This practice flushes out the aquifer around the well and builds up a buffer zone that can maintain high recovery efficiency in the subsequent cycles. The relative performance of all sites with adequate cycle test data was determined. Performance was arbitrarily grouped into ?high? (greater than 40 percent), ?medium? (between 20 and 40 percent), and ?low? (less than 20 percent) categories based primarily on their cumulative recovery efficiency for the first seven cycles, or projected to seven cycles if fewer cycles were conducted. The ratings of three sites, considered to be borderline, were modified using the overall recharge rate derived from the cumulative recharge volumes. A higher overall recharge rate (greater than 300 million gallons per year) can improve recovery efficiency because of the water-bankin

  20. Base of aquifer contours for the Northern High Plains aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Several pre-existing datasets that characterize portions of the Northern High Plains aquifer base were merged together in order to define the entire base of the...

  1. Contrasting definitions for the term `karst aquifer'

    Science.gov (United States)

    Worthington, Stephen R. H.; Jeannin, Pierre-Yves; Alexander, E. Calvin; Davies, Gareth J.; Schindel, Geary M.

    2017-08-01

    It is generally considered that karst aquifers have distinctly different properties from other bedrock aquifers. A search of the literature found five definitions that have been proposed to differentiate karst aquifers from non-karstic aquifers. The five definitions are based upon the presence of solution channel networks, hydraulic conductivities >10-6 m/s, karst landscapes, channels with turbulent flow, and caves. The percentage of unconfined carbonate aquifers that would classify as `karst' ranges from 50%.

  2. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer covers...

  3. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000 acres and...

  4. Mississippi River Valley alluvial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippi River Valley alluvial aquifer in the states of Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and...

  5. Region 9 Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are 7 polygons representing 6 individual sole source aquifer boundaries and one streamflow source area in California, Arizona, and Nevada. Various efforts were...

  6. Southeastern Coastal Plain aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Southeastern Coastal Plain aquifer system in Kentucky, Tennessee, Mississippi, Alabama, Georgia, and South Carolina.

  7. Microbial dynamics in natural aquifers

    OpenAIRE

    Bajracharya, Bijendra Man

    2016-01-01

    Microorganisms in groundwater form ecosystems that can transform chemical compounds. Quantitatively understanding microbial dynamics in soils and groundwater is thus essential for pollutant dynamics and biogeochemistry in the subsurface. This dissertation addresses three factors influencing microbial dynamics in aquifers and soils, namely: (1) the influence of grazing on bacteria in eutrophic aquifers, posing the question whether the carrying capacity of bacteria, which has been observed i...

  8. Aquifer response to recharge-discharge phenomenon: inference from well hydrographs for genetic classification

    Science.gov (United States)

    Mukherjee, Arunangshu; Gupta, Anita; Ray, Ranjan Kumar; Tewari, Dinesh

    2017-05-01

    The continuous groundwater level data emanating from a high-frequency automatic water level recorder installed in a purpose-built piezometer provides a true hydrograph. Analyses of such hydrographs fairly reflect the aquifer character and can be used to draw inference for genetic classification of hard rock aquifers. The signature shape of annual water level fluctuation curve (annual cycle) of a piezometer is due to the specific character of the aquifer and the way it responds to the recharge-discharge phenomenon. The pattern of annual cycle remains identical year after year, although its magnitude may vary with the annual quantum of recharge-discharge. Lithology of the aquifer does not control the shape of the curve. Based on the crest and trough shape, the hard rock aquifers of Peninsular India, where the monsoonal pattern of rainfall occurs, have been classified into genetic groups. It is also found that the nature of the aquifer can be determined by visual comparison of apparent line thickness of the hydrograph, where thin lines denote unconfined aquifer and the apparently thicker lines correspond to confining condition. The response of an aquifer to a pumping event can be identified and separated by its pattern. Thus, the aquifer classification can be automated by adopting the proposed classification scheme.

  9. Characterising aquifer treatment for pathogens in managed aquifer recharge.

    Science.gov (United States)

    Page, D; Dillon, P; Toze, S; Sidhu, J P S

    2010-01-01

    In this study the value of subsurface treatment of urban stormwater during Aquifer Storage Transfer Recovery (ASTR) is characterised using quantitative microbial risk assessment (QMRA) methodology. The ASTR project utilizes a multi-barrier treatment train to treat urban stormwater but to date the role of the aquifer has not been quantified. In this study it was estimated that the aquifer barrier provided 1.4, 2.6, >6.0 log(10) removals for rotavirus, Cryptosporidium and Campylobacter respectively based on pathogen diffusion chamber results. The aquifer treatment barrier was found to vary in importance vis-à-vis the pre-treatment via a constructed wetland and potential post-treatment options of UV-disinfection and chlorination for the reference pathogens. The risk assessment demonstrated that the human health risk associated with potable reuse of stormwater can be mitigated (disability adjusted life years, DALYs aquifer is integrated with suitable post treatment options into a treatment train to attenuate pathogens and protect human health.

  10. ANALYTICAL ELEMENT MODELING OF COASTAL AQUIFERS

    Science.gov (United States)

    Four topics were studied concerning the modeling of groundwater flow in coastal aquifers with analytic elements: (1) practical experience was obtained by constructing a groundwater model of the shallow aquifers below the Delmarva Peninsula USA using the commercial program MVAEM; ...

  11. Saturated thickness, High Plains aquifer, 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents the saturated thickness of the High Plains aquifer of the United States, 2009, in feet. The High Plains aquifer underlies...

  12. ANALYTICAL ELEMENT MODELING OF COASTAL AQUIFERS

    Science.gov (United States)

    Four topics were studied concerning the modeling of groundwater flow in coastal aquifers with analytic elements: (1) practical experience was obtained by constructing a groundwater model of the shallow aquifers below the Delmarva Peninsula USA using the commercial program MVAEM; ...

  13. National Sole Source Aquifer GIS Layer

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data set contains indexes and Esri shape files of boundaries of the designated sole source aquifers and related aquifer boundaries. Data provide a vector...

  14. Fluoride in the Serra Geral Aquifer System: Source Evaluation Using Stable Isotopes and Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Arthur Schmidt Nanni

    2013-01-01

    Full Text Available Groundwater with anomalous fluoride content and water mixture patterns were studied in the fractured Serra Geral Aquifer System, a basaltic to rhyolitic geological unit, using a principal component analysis interpretation of groundwater chemical data from 309 deep wells distributed in the Rio Grande do Sul State, Southern Brazil. A four-component model that explains 81% of the total variance in the Principal Component Analysis is suggested. Six hydrochemical groups were identified. δ18O and δ2H were analyzed in 28 Serra Geral Aquifer System samples in order to identify stable isotopes patterns and make comparisons with data from the Guarani Aquifer System and meteoric waters. The results demonstrated a complex water mixture between the Serra Geral Aquifer System and the Guarani Aquifer System, with meteoric recharge and ascending water infiltration through an intensive tectonic fracturing.

  15. Carbonate Chemistry and Isotope Characteristics of Groundwater of Ljubljansko Polje and Ljubljansko Barje Aquifers in Slovenia

    Science.gov (United States)

    2013-01-01

    Ljubljansko polje and Ljubljansko Barje aquifers are the main groundwater resources for the needs of Ljubljana, the capital of Slovenia. Carbonate chemistry and isotope analysis of the groundwater were performed to acquire new hydrogeological data, which should serve as a base for improvement of hydrogeological conceptual models of both aquifers. A total of 138 groundwater samples were collected at 69 sampling locations from both aquifers. Major carbonate ions and the stable isotope of oxygen were used to identify differences in the recharging areas of aquifers. Four groups of groundwater were identified: (1) Ljubljansko polje aquifer, with higher Ca2+values, as limestone predominates in its recharge area, (2) northern part of Ljubljansko Barje aquifer, with prevailing dolomite in its recharge area, (3) central part of Ljubljansko Barje aquifer, which lies below surface cover of impermeable clay and is poor in carbonate, and (4) Brest and Iški vršaj aquifer in the southern part of Ljubljansko Barje with higher Mg2+ in groundwater and dolomite prevailing in its recharge area. The radioactive isotope tritium was also used to estimate the age of groundwater. Sampled groundwater is recent with tritium activity between 4 and 8 TU and residence time of up to 10 years. PMID:24453928

  16. Carbonate Chemistry and Isotope Characteristics of Groundwater of Ljubljansko Polje and Ljubljansko Barje Aquifers in Slovenia

    Directory of Open Access Journals (Sweden)

    Sonja Cerar

    2013-01-01

    Full Text Available Ljubljansko polje and Ljubljansko Barje aquifers are the main groundwater resources for the needs of Ljubljana, the capital of Slovenia. Carbonate chemistry and isotope analysis of the groundwater were performed to acquire new hydrogeological data, which should serve as a base for improvement of hydrogeological conceptual models of both aquifers. A total of 138 groundwater samples were collected at 69 sampling locations from both aquifers. Major carbonate ions and the stable isotope of oxygen were used to identify differences in the recharging areas of aquifers. Four groups of groundwater were identified: (1 Ljubljansko polje aquifer, with higher Ca2+ values, as limestone predominates in its recharge area, (2 northern part of Ljubljansko Barje aquifer, with prevailing dolomite in its recharge area, (3 central part of Ljubljansko Barje aquifer, which lies below surface cover of impermeable clay and is poor in carbonate, and (4 Brest and Iški vršaj aquifer in the southern part of Ljubljansko Barje with higher Mg2+ in groundwater and dolomite prevailing in its recharge area. The radioactive isotope tritium was also used to estimate the age of groundwater. Sampled groundwater is recent with tritium activity between 4 and 8 TU and residence time of up to 10 years.

  17. Carbonate chemistry and isotope characteristics of groundwater of Ljubljansko polje and Ljubljansko Barje aquifers in Slovenia.

    Science.gov (United States)

    Cerar, Sonja; Urbanc, Janko

    2013-01-01

    Ljubljansko polje and Ljubljansko Barje aquifers are the main groundwater resources for the needs of Ljubljana, the capital of Slovenia. Carbonate chemistry and isotope analysis of the groundwater were performed to acquire new hydrogeological data, which should serve as a base for improvement of hydrogeological conceptual models of both aquifers. A total of 138 groundwater samples were collected at 69 sampling locations from both aquifers. Major carbonate ions and the stable isotope of oxygen were used to identify differences in the recharging areas of aquifers. Four groups of groundwater were identified: (1) Ljubljansko polje aquifer, with higher Ca(2+)values, as limestone predominates in its recharge area, (2) northern part of Ljubljansko Barje aquifer, with prevailing dolomite in its recharge area, (3) central part of Ljubljansko Barje aquifer, which lies below surface cover of impermeable clay and is poor in carbonate, and (4) Brest and Iški vršaj aquifer in the southern part of Ljubljansko Barje with higher Mg(2+) in groundwater and dolomite prevailing in its recharge area. The radioactive isotope tritium was also used to estimate the age of groundwater. Sampled groundwater is recent with tritium activity between 4 and 8 TU and residence time of up to 10 years.

  18. Hydrologic and Geochemical Evaluation of Aquifer Storage Recovery in the Santee Limestone/Black Mingo Aquifer, Charleston, South Carolina, 1998-2002

    Science.gov (United States)

    Petkewich, Matthew D.; Parkhurst, David L.; Conlon, Kevin J.; Campbell, Bruce G.; Mirecki, June E.

    2004-01-01

    The hydrologic and geochemical effects of aquifer storage recovery were evaluated to determine the potential for supplying the city of Charleston, South Carolina, with large quantities of potable water during emergencies, such as earthquakes, hurricanes, or hard freezes. An aquifer storage recovery system, including a production well and three observation wells, was installed at a site located on the Charleston peninsula. The focus of this study was the 23.2-meter thick Tertiary-age carbonate and sand aquifer of the Santee Limestone and the Black Mingo Group, the northernmost equivalent of the Floridan aquifer system. Four cycles of injection, storage, and recovery were conducted between October 1999 and February 2002. Each cycle consisted of injecting between 6.90 and 7.19 million liters of water for storage periods of 1, 3, or 6 months. The volume of recovered water that did not exceed the U.S. Environmental Protection Agency secondary standard for chloride (250 milligrams per liter) varied from 1.48 to 2.46 million liters, which is equivalent to 21 and 34 percent of the total volume injected for the individual tests. Aquifer storage recovery testing occurred within two productive zones of the brackish Santee Limestone/Black Mingo aquifer. The individual productive zones were determined to be approximately 2 to 4 meters thick, based on borehole geophysical logs, electromagnetic flow-meter testing, and specific-conductance profiles collected within the observation wells. A transmissivity and storage coefficient of 37 meters squared per day and 3 x 10-5, respectively, were determined for the Santee Limestone/Black Mingo aquifer. Water-quality and sediment samples collected during this investigation documented baseline aquifer and injected water quality, aquifer matrix composition, and changes in injected/aquifer water quality during injection, storage, and recovery. A total of 193 water-quality samples were collected and analyzed for physical properties, major and

  19. Hydrogeology of the gray limestone aquifer in southern Florida

    Science.gov (United States)

    Reese, Ronald S.; Cunningham, Kevin J.

    2000-01-01

    Results from 35 new test coreholes and aquifer-test, water-level, and water-quality data were combined with existing hydrogeologic data to define the extent, thickness, hydraulic properties, and degree of confinement of the gray limestone aquifer in southern Florida. This aquifer, previously known to be present only in southeastern Florida (Miami-Dade, Broward, and Palm Beach Counties) below, and to the west of, the Biscayne aquifer, extends over most of central-south Florida, including eastern and central Collier County and southern Hendry County; it is the same as the lower Tamiami aquifer to the north, and it becomes the water-table aquifer and the upper limestone part of the lower Tamiami aquifer to the west. The aquifer generally is composed of gray, shelly, lightly to moderately cemented limestone with abundant shell fragments or carbonate sand, abundant skeletal moldic porosity, and minor quartz sand. The gray limestone aquifer comprises the Ochopee Limestone of the Tamiami Formation, and, in some areas, the uppermost permeable part of an unnamed formation principally composed of quartz sand. Underlying the unnamed formation is the Peace River Formation of the upper Hawthorn Group, the top of which is the base of the surficial aquifer system. Overlying the aquifer and providing confinement in much of the area is the Pinecrest Sand Member of the Tamiami Formation. The thickness of the aquifer is comparatively uniform, generally ranging from 30 to 100 feet. The unnamed formation part of the aquifer is up to 20 feet thick. The Ochopee Limestone accumulated in a carbonate ramp depositional system and contains a heterozoan carbonate-particle association. The principal rock types of the aquifer are pelecypod lime rudstones and floatstones and permeable quartz sands and sandstones. The pore types are mainly intergrain and separate vug (skeletal-moldic) pore spaces. The rock fabric and associated primary and secondary pore spaces combine to form a dual diffuse

  20. Investigating groundwater arsenic contamination using aquifer push-pull test

    Science.gov (United States)

    Daigle, A. R.; Jin, Q.

    2009-12-01

    The groundwater of the Southern Willamette Basin, OR is contaminated with arsenic at concentrations as high as several ppm. A single-well push-pull test was conducted to investigate how microbial metabolisms control arsenic occurrence and levels in the bedrock aquifer of the area. During the experiments, a test solution containing ethanol was first injected into the aquifer. As the experiment progressed, dissolved gasses, groundwater, and sediment were sampled to monitor the variations in the chemical parameters, including the speciation of iron, sulfur, and arsenic, in the aquifer. Ethanol amendment stimulated a series of microbial metabolisms, including arsenate reduction, iron reduction, and sulfate reduction. Iron reduction released arsenic sorbed onto the aquifer sediments, increasing groundwater arsenic levels. Arsenate reduction converted arsenate to arsenite and, as a result, most arsenic occurred as arsenite in the groundwater. Results of the experiments demonstrate how different microbial functional groups influenced arsenic contamination in the area. These results also shed new light on potential bioremediation strategies in the area.

  1. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries created for a previously published report about the Central Oklahoma aquifer in central Oklahoma. This area...

  2. Digital data sets that describe aquifer characteristics of the Rush Springs aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Rush Springs aquifer in western Oklahoma. This area encompasses all or part of Blaine, Caddo,...

  3. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Elk City aquifer in western Oklahoma. The aquifer covers an area of...

  4. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant recharge values for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately...

  5. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer...

  6. Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries of the Antlers aquifer in southeastern Oklahoma. The Early Cretaceous-age Antlers Sandstone is an important...

  7. Digital data sets that describe aquifer characteristics of the Elk City aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000...

  8. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the High Plains aquifer in western Oklahoma. This area encompasses the panhandle counties of Cimarron,...

  9. Geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers within northern Bexar and Comal Counties, Texas

    Science.gov (United States)

    Clark, Allan K.; Golab, James A.; Morris, Robert R.

    2016-11-28

    During 2014–16, the U.S. Geological Survey, in cooperation with the Edwards Aquifer Authority, documented the geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers within northern Bexar and Comal Counties, Texas. The Edwards and Trinity aquifers are major sources of water for agriculture, industry, and urban and rural communities in south-central Texas. Both the Edwards and Trinity are classified as major aquifers by the State of Texas.The purpose of this report is to present the geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers within northern Bexar and Comal Counties, Tex. The report includes a detailed 1:24,000-scale hydrostratigraphic map, names, and descriptions of the geology and hydrostratigraphic units (HSUs) in the study area.The scope of the report is focused on geologic framework and hydrostratigraphy of the outcrops and hydrostratigraphy of the Edwards and Trinity aquifers within northern Bexar and Comal Counties, Tex. In addition, parts of the adjacent upper confining unit to the Edwards aquifer are included.The study area, approximately 866 square miles, is within the outcrops of the Edwards and Trinity aquifers and overlying confining units (Washita, Eagle Ford, Austin, and Taylor Groups) in northern Bexar and Comal Counties, Tex. The rocks within the study area are sedimentary and range in age from Early to Late Cretaceous. The Miocene-age Balcones fault zone is the primary structural feature within the study area. The fault zone is an extensional system of faults that generally trends southwest to northeast in south-central Texas. The faults have normal throw, are en echelon, and are mostly downthrown to the southeast.The Early Cretaceous Edwards Group rocks were deposited in an open marine to supratidal flats environment during two marine transgressions. The Edwards Group is composed of the Kainer and Person Formations. Following tectonic uplift, subaerial exposure, and erosion near the end of

  10. Death Valley Lower Carbonate Aquifer Monitoring Program Wells Down Gradient of the Proposed Yucca Mountain Nuclear Waste Repository, U. S. Department of Energy Grant DE-RW0000233 2010 Project Report, prepared by The Hydrodynamics Group, LLC for Inyo County Yucca Mountain Repository Assessment Office

    Energy Technology Data Exchange (ETDEWEB)

    King, Michael J; Bredehoeft, John D., Dr.

    2010-09-03

    Inyo County completed the first year of the U.S. Department of Energy Grant Agreement No. DE-RW0000233. This report presents the results of research conducted within this Grant agreement in the context of Inyo County's Yucca Mountain oversight program goals and objectives. The Hydrodynamics Group, LLC prepared this report for Inyo County Yucca Mountain Repository Assessment Office. The overall goal of Inyo County's Yucca Mountain research program is the evaluation of far-field issues related to potential transport, by ground water, of radionuclide into Inyo County, including Death Valley, and the evaluation of a connection between the Lower Carbonate Aquifer (LCA) and the biosphere. Data collected within the Grant is included in interpretive illustrations and discussions of the results of our analysis. The centeral elements of this Grant prgoram was the drilling of exploratory wells, geophysical surveys, geological mapping of the Southern Funeral Mountain Range. The cullimination of this research was 1) a numerical ground water model of the Southern Funeral Mountain Range demonstrating the potential of a hydraulic connection between the LCA and the major springs in the Furnace Creek area of Death Valley, and 2) a numerical ground water model of the Amargosa Valley to evaluate the potential for radionuclide transport from Yucca Mountain to Inyo County, California. The report provides a description of research and activities performed by The Hydrodynamics Group, LLC on behalf of Inyo County, and copies of key work products in attachments to this report.

  11. Quantification of the reactions in heat storage systems in the Malm aquifer

    Science.gov (United States)

    Ueckert, Martina; Baumann, Thomas

    2017-04-01

    Combined heat and power plants (CHP) are efficient and environmentally friendly because excess heat produced during power generation is used for heating purposes. While the power demand remains rather constant throughout the year, the heat demand shows seasonal variations. In a worst-case scenario, the heat production in winter is not sufficient, and the power production in summer has to be ramped down because the excess heat cannot be released to the environment. Therefore, storage of excess heat of CHP is highly beneficial from an economic and an ecological point of view. Aquifer thermal energy storage (ATES) is considered as a promising technology for energy storage. In a typical setting, water from an aquifer is produced, heated up by excess heat from the CHP and injected through a second borehole back into the aquifer. The carbonate rocks of the upper Jurrasic in the Molasse Basin seem to be promising sites for aquifer heat storage because of their high transmissivity combined with a typical geological setting with tight caprock. However, reactions in the aquifer cannot be neglected and may become the limiting process of the whole operation. While there have been several studies performed in clastic aquifers and for temperatures below 100°C, the knowledge about high injection temperatures and storage into a carbonatic aquifer matrix is still limited. Within a research project funded by the Bavarian State Ministry for Economic Affairs and the BMW Group, the storage and recuperation of excess heat energy into the Bavarian Malm aquifer with flow rates of 15 L/s and temperatures of up to 110°C was investigated. The addition of {CO_2} was used to prevent precipitations. Data from the field site was backed up by autoclave experiments and used to verify a conceptional hydrogeochemical model with PhreeqC for the heat storage operation. The model allows to parametrize the operation and to predict possible reactions in the aquifer.

  12. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace aquifer encompasses...

  13. Digital data sets that describe aquifer characteristics of the Vamoosa-Ada aquifer in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Vamoosa-Ada aquifer in east-central Oklahoma. The Vamoosa-Ada aquifer is an important source of water...

  14. Drought-sensitive aquifer settings in southeastern Pennsylvania

    Science.gov (United States)

    Zimmerman, Tammy M.; Risser, Dennis W.

    2005-01-01

    This report describes the results of a study conducted by the U.S. Geological Survey, in cooperation with the Pennsylvania Department of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey, to determine drought-sensitive aquifer settings in southeastern Pennsylvania. Because all or parts of southeastern Pennsylvania have been in drought-warning or drought-emergency status during 6 of the past 10 years from 1994 through 2004, this information should aid well owners, drillers, and water-resource managers in guiding appropriate well construction and sustainable use of Pennsylvania's water resources. 'Drought-sensitive' aquifer settings are defined for this study as areas unable to supply adequate quantities of water to wells during drought. Using information from previous investigations and a knowledge of the hydrogeology and topography of the study area, drought-sensitive aquifer settings in southeastern Pennsylvania were hypothesized as being associated with two factors - a water-table decline (WTD) index and topographic setting. The WTD index is an estimate of the theoretical water-table decline at the ground-water divide for a hypothetical aquifer with idealized geometry. The index shows the magnitude of ground-water decline after cessation of recharge is a function of (1) distance from stream to divide, (2) ground-water recharge rate, (3) transmissivity, (4) specific yield, and (5) duration of the drought. WTD indices were developed for 39 aquifers that were subsequently grouped into categories of high, moderate, and low WTD index. Drought-sensitive settings determined from the hypothesized factors were compared to locations of wells known to have been affected (gone dry, replaced, or deepened) during recent droughts. Information collected from well owners, drillers, and public agencies identified 2,016 wells affected by drought during 1998-2002. Most of the available data on the location of drought-affected wells in the study area were

  15. Recharge rates and aquifer hydraulic characteristics for selected drainage basins in middle and east Tennessee

    Science.gov (United States)

    Hoos, A.B.

    1990-01-01

    Quantitative information concerning aquifer hydrologic and hydraulic characteristics is needed to manage the development of ground-water resources. These characteristics are poorly defined for the bedrock aquifers in Middle and East Tennessee where demand for water is increasing. This report presents estimates of recharge rate, storage coefficient, diffusivity, and transmissivity for representative drainage basins in Middle and East Tennessee, as determined from analyses of stream-aquifer interactions. The drainage basins have been grouped according to the underlying major aquifer, then statistical descriptions applied to each group, in order to define area1 distribution of these characteristics. Aquifer recharge rates are estimated for representative low, average, and high flow years for 63 drainage basins using hydrograph analysis techniques. Net annual recharge during average flow years for all basins ranges from 4.1 to 16.8 in/yr (inches per year), with a mean value of 7.3 in. In general, recharge rates are highest for basins underlain by the Blue Ridge aquifer (mean value11.7 in/yr) and lowest for basins underlain by the Central Basin aquifer (mean value 5.6 in/yr). Mean recharge values for the Cumberland Plateau, Highland Rim, and Valley and Ridge aquifers are 6.5, 7.4, and 6.6 in/yr, respectively. Gravity drainage characterizes ground-water flow in most surficial bedrock aquifer in Tennessee. Accordingly, a gravity yield analysis, which compares concurrent water-level and streamflow hydrographs, was used to estimate aquifer storage coefficient for nine study basins. The basin estimates range from 0.002 to 0.140; however, most estimates are within a narrow range of values, from 0.01 to 0.025. Accordingly, storage coefficient is estimated to be 0.01 for all aquifers in Middle and East Tennessee, with the exception of the aquifer in the inner part of the Central Basin, for which storage coefficient is estimated to be 0.002. Estimates of aquifer hydraulic

  16. Hydrogeochemical analysis for Tasuj plain aquifer, Iran

    Indian Academy of Sciences (India)

    Ata Allah Nadiri; Asghar Asghari Moghaddam; Frank T-C Tsai; Elham Fijani

    2013-08-01

    This study investigated the hydrogeochemical processes of groundwater in the Tasuj plain, Iran. The Tasuj plain is one of the 12 marginal plains around Urmia Lake which is currently under a critical ecological condition. In the last decades, the Tasuj plain aquifer suffered from severe groundwater level declination and caused degradation of groundwater quality. To better understand hydrogeochemical processes in the Tasuj plain, this study adopted graphical methods and multivariate statistical techniques to analyze groundwater samples. A total of 504 groundwater samples was obtained from 34 different locations (qanats, wells, and springs) over 12 years (1997–2009) and analyzed for 15 water quality parameters. From the results, the Piper diagram indicated four groundwater types and the Stiff diagram showed eight different sources of groundwater samples. The Durov diagram identified five major hydrogeochemical processes in the aquifer. However, hierarchical cluster analysis (HCA) identified five water types in the groundwater samples because HCA was able to analyze more chemical and physical data than graphical methods. The HCA result was checked by discriminant analysis and found consistency in all samples that were classified into correct groups. Using factor analysis, we identified three factors that accounted for 81.6% of the total variance of the dataset. Based on the high factor loadings of the variables, factors 1 and 2 reflected the natural hydrogeochemical processes and factor 3 explained the effect of agricultural fertilizers and human activities in the Tasuj plain. Dendrograms from 2000 to 2009 were studied to understand the temporal variation of groundwater quality. Comparing the distributions of groundwater types in 2000 and 2009, we found that the mixing zone was expanded. This may be due to artificial groundwater recharge in the recharge area and the effect of inverse ion exchange in the discharge area.

  17. Overview of the Ogallala Aquifer Program

    Science.gov (United States)

    Irrigation increased markedly on the Southern High Plains during the second half of the 20th century, drawing water primarily from the Ogallala Aquifer. During this time, irrigation sustained regional farm incomes and rural economies. Withdrawals from the aquifer, however, have exceeded recharge, re...

  18. Geohydrology of the Cerro Prieto geothermal aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez R, J.; de la Pena L, A.

    1981-01-01

    The most recent information on the Cerro Prieto geothermal aquifer is summarized, with special emphasis on the initial production zone where the wells completed in the Alpha aquifer are located. These wells produce steam for power plant units 1 and 2. Brief comments also are made on the Beta aquifer, which underlies the Alpha aquifer in the Cerro Prieto I area and which extends to the east to what is known as the Cerro Prieto II and Cerro Prieto III areas. The location of the area studied is shown. The Alpha and Beta aquifers differ in their mineralogy and cementing mineral composition, temperatures, and piezometric levels. The difference in piezometric levels indicates that there is no local communication between the two aquifers. This situation has been verified by a well interference test, using well E-1 as a producer in the Beta aquifer and well M-46 as the observation well in the Alpha aquifer. No interference between them was observed. Information on the geology, geohydrology, and geochemistry of Cerro Prieto is presented.

  19. Geochemistry of the Arbuckle-Simpson Aquifer

    Science.gov (United States)

    Christenson, Scott; Hunt, Andrew G.; Parkhurst, David L.; Osborn, Noel I.

    2009-01-01

    The Arbuckle-Simpson aquifer in south-central Oklahoma provides water for public supply, farms, mining, wildlife conservation, recreation, and the scenic beauty of springs, streams, and waterfalls. A new understanding of the aquifer flow system was developed as part of the Arbuckle-Simpson Hydrology Study, done in 2003 through 2008 as a collaborative research project between the State of Oklahoma and the Federal government. The U.S. Geological Survey collected 36 water samples from 32 wells and springs in the Arbuckle-Simpson aquifer in 2004 through 2006 for geochemical analyses of major ions, trace elements, isotopes of oxygen and hydrogen, dissolved gases, and dating tracers. The geochemical analyses were used to characterize the water quality in the aquifer, to describe the origin and movement of ground water from recharge areas to discharge at wells and springs, and to determine the age of water in the aquifer.

  20. Aquifer Vulnerability maps and climate change

    Science.gov (United States)

    Ducci, Daniela; Sellerino, Mariangela

    2017-04-01

    The aquifer vulnerability maps to contamination are used worldwide by environmental agencies and water-resource managers with the aim of preserving the water resources and of evaluating the most suitable areas where to locate new settlements. In the parametric methods, more used to assess the groundwater contamination vulnerability, e.g. the DRASTIC and the AVI methods, an important role is played by the protective capacity of cover layers to the introduction and transport of contaminants into the aquifer. Therefore, these methods point out the importance of the "Depth to water" parameter, which represents, where the aquifer is unconfined, the depth of the piezometric level and, where the aquifer is confined, the top of the aquifer. This parameter is rarely variable in confined aquifers and in deep unconfined aquifers, as karst aquifers, where the piezometric oscillations are low, compared with the depth of the water table. On the contrary, in shallow aquifers of flat areas, where in addition a large number of human activities are practiced and the contamination risk is high, the piezometric level varies suddenly with the rainfall, and it is very sensitive to drought periods and climatic changes. This affects noticeably the "Depth to water" parameter and consequently the vulnerability maps (e.g. 3 m of piezometric lowering can produce a change in the DRASTIC index from 10 to 7…). To validate this hypothesis, the DRASTC and AVI methods have been applied on a shallow aquifer located in a flat area in Campania (Italy,) considering data corresponding to an average rainfall period and to a drought period.

  1. Hydrology of the Texas Gulf Coast aquifer systems

    Science.gov (United States)

    Ryder, P.D.; Ardis, A.F.

    1991-01-01

    A complex, multilayered ground-water flow system exists in the Coastal Plain sediments of Texas. The Tertiary and Quaternary clastic deposits have an areal extent of 114,000 square miles onshore and in the Gulf of Mexico. Two distinct aquifer systems are recognized within the sediments, which range in thickness from a few feet to more than 12,000 feet The older system--the Texas coastal uplands aquifer system-consists of four aquifers and two confining units in the Claiborne and Wilcox Groups. It is underlain by the practically impermeable Midway confining unit or by the top of the geopressured zone. It is overlain by the nearly impermeable Vicksburg-Jackson confining unit, which separates it from the younger coastal lowlands aquifer system. The coastal lowlands aquifer system consists of five permeable zones and two confining units that range in age from Oligocene to Holocene. The hydrogeologic units of both systems are exposed in bands that parallel the coastline. The units dip and thicken toward the Gulf. Quality of water in the aquifer systems is highly variable, with dissolved solids ranging from less than 500 to 150,000 milligrams per liter. Substantial withdrawal from the aquifer systems began in the early 1900's and increased nearly continuously into the 1970's. The increase in withdrawal was relatively rapid from about 1940 to 1970. Adverse hydrologic effects, such as saltwater encroachment in coastal areas, land-surface subsidence in the HoustonGalveston area, and long-term dewatering in the Whiter Garden area, were among some of the factors that caused pumping increases to slow or to cease in the 1970's and 1980's. Ground-water withdrawals in the study area in 1980 were about 1.7 billion gallons per day. Nearly all of the withdrawal was from four units: Permeable zones A, B, and C of Miocene age and younger, and the lower Claiborae-upper Wilcox aquifer. Ground-water levels have declined hundreds of feet in the intensively pumped areas of Houston

  2. Economics of Managed Aquifer Recharge

    Directory of Open Access Journals (Sweden)

    Robert G. Maliva

    2014-05-01

    Full Text Available Managed aquifer recharge (MAR technologies can provide a variety of water resources management benefits by increasing the volume of stored water and improving water quality through natural aquifer treatment processes. Implementation of MAR is often hampered by the absence of a clear economic case for the investment to construct and operate the systems. Economic feasibility can be evaluated using cost benefit analysis (CBA, with the challenge of monetizing benefits. The value of water stored or treated by MAR systems can be evaluated by direct and indirect measures of willingness to pay including market price, alternative cost, value marginal product, damage cost avoided, and contingent value methods. CBAs need to incorporate potential risks and uncertainties, such as failure to meet performance objectives. MAR projects involving high value uses, such as potable supply, tend to be economically feasible provided that local hydrogeologic conditions are favorable. They need to have low construction and operational costs for lesser value uses, such as some irrigation. Such systems should therefore be financed by project beneficiaries, but dichotomies may exist between beneficiaries and payers. Hence, MAR projects in developing countries may be economically viable, but external support is often required because of limited local financial resources.

  3. The importance of some carbonate aquifers in the Guadalquivir river basin; Importancia de algunos acuiferos carbonatados representativos de la cuenca del Guadalquivir

    Energy Technology Data Exchange (ETDEWEB)

    Pulido Boch, A.; Lopez Chicano, M.

    1995-07-01

    Carbonate aquifers play an important role in the Guadalquivir river basin, although, until present days, there are very few wells exploiting them. We can distinguish two kinds of carbonate aquifers: fissurated and karstic. In the first group, we consider the Alpujarride carbonates from the western Sierra Nevada- Alfaguara border; in the second, the most important are: Cazorla and Segura Sierras-source of the Guadalquivir river- and Sierra Gorda. The main hydrogeological characteristics of these aquifers are described and we make some reflexions about the role that the aquifers can play in the total resources of the basin. (Author)

  4. Hydrology of the Claiborne aquifer and interconnection with the Upper Floridan aquifer in southwest Georgia

    Science.gov (United States)

    Gordon, Debbie W.; Gonthier, Gerard

    2017-04-24

    The U.S. Geological Survey conducted a study, in cooperation with the Georgia Environmental Protection Division, to define the hydrologic properties of the Claiborne aquifer and evaluate its connection with the Upper Floridan aquifer in southwest Georgia. The effort involved collecting and compiling hydrologic data from the aquifer in subarea 4 of southwestern Georgia. Data collected for this study include borehole geophysical logs in 7 wells, and two 72-hour aquifer tests to determine aquifer properties.The top of the Claiborne aquifer extends from an altitude of about 200 feet above the North American Vertical Datum of 1988 (NAVD 88) in Terrell County to 402 feet below NAVD 88 in Decatur County, Georgia. The base of the aquifer extends from an altitude of about 60 feet above NAVD 88 in eastern Sumter County to about 750 feet below NAVD 88 in Decatur County. Aquifer thickness ranges from about 70 feet in eastern Early County to 400 feet in Decatur County.The transmissivity of the Claiborne aquifer, determined from two 72-hour aquifer tests, was estimated to be 1,500 and 700 feet squared per day in Mitchell and Early Counties, respectively. The storage coefficient was estimated to be 0.0006 and 0.0004 for the same sites, respectively. Aquifer test data from Mitchell County indicate a small amount of leakage occurred during the test. Groundwater-flow models suggest that the source of the leakage was the underlying Clayton aquifer, which produced about 2.5 feet of drawdown in response to pumping in the Claiborne aquifer. The vertical hydraulic conductivity of the confining unit between the Claiborne and Clayton aquifers was simulated to be about 0.02 foot per day.Results from the 72-hour aquifer tests run for this study indicated no interconnection between the Claiborne and overlying Upper Floridan aquifers at the two test sites. Additional data are needed to monitor the effects that increased withdrawals from the Claiborne aquifer may have on future water resources.

  5. Radium contamination in the Nizzana-1 water well, Negev Desert, Israel

    Energy Technology Data Exchange (ETDEWEB)

    Minster, T. E-mail: tsevi.minster@mail.gsi.gov.il; Ilani, S.; Kronfeld, J.; Even, O.; Godfrey-Smith, D.I

    2004-07-01

    In a search for fresh groundwater reserves in the northwestern Negev Desert of Israel, the Nizzana-1 water well drilled into the Judea Group aquifer encountered water that exhibits an anomalously high {sup 226}Ra activity of 2.4 Bq/l, along with 133 Bq/l {sup 222}Rn. The exploited well water is a mixture of the original Judea Group aquifer water and the underlying more saline artesian water of the Kurnub Group (or Nubian Sandstone) aquifer that is currently intruding via faults. Both aquifers elsewhere contain intrinsically low radioactivity. A study of the sedimentary sequence transected by the borehole revealed that much of the bituminous sequence of the Mount Scopus Group of Upper Cretaceous age is substantially depleted in {sup 226}Ra. During its ascent, the Nubian Sandstone water flushes the moderately uranium enriched bituminous sediments, selectively leaching radium and/or receiving alpha-recoil additions of radium. These bituminous chalks and marls are regionally widespread. It is thus suggested that radium should be monitored where faulting allows for inter-aquiferial connections across uranium enriched bituminous sections.

  6. Radial Dupuit interface flow to assess the aquifer storage and recovery potential of saltwater aquifers

    OpenAIRE

    Bakker, M

    2009-01-01

    A new accurate numerical solution is presented for aquifer storage and recovery (ASR) systems in coastal aquifers; flow is approximated as radial Dupuit interface flow. The radial velocities of points on the interface are a function of time, the vertical coordinate, and the dimensionless parameter D (the discharge of the well divided by the product of the hydraulic conductivity, the square of the aquifer thickness, and the dimensionless density difference). The recovery efficiency of an ASR s...

  7. Solute changes during aquifer storage recovery testing in a limestone/clastic aquifer

    Science.gov (United States)

    Mirecki, J.E.; Campbell, B.G.; Conlon, K.J.; Petkewich, M.D.

    1998-01-01

    Aquifer storage recovery (ASR) was tested in the Santee Limestone/Black Mingo Aquifer near Charleston, South Carolina, to assess the feasibility for subsurface storage of treated drinking water. Water quality data obtained during two representative ASR tests were interpreted to show three things: (1) recovery efficiency of ASR in this geological setting; (2) possible changes in physical characteristics of the aquifer during ASR testing; and (3) water quality changes and potability of recovered water during short (one- and six-day) storage durations in the predominantly carbonate aquifer. Recovery efficiency for both ASR tests reported here was 54%. Successive ASR tests increased aquifer permeability of the Santee Limestone/Black Mingo Aquifer. It is likely that aquifer permeability increased during short storage periods due to dissolution of carbonate minerals and amorphous silica in aquifer material by treated drinking water. Dissolution resulted in an estimated 0.3% increase in pore volume of the permeable zones. Ground water composition generally evolved from a sodium-calcium bicarbonate water to a sodium chloride water during storage and recovery. After short duration, stored water can exceed the U.S. Environmental Protection Agency maximum contaminant level (MCL) for chloride (250 mg/L). However, sulfate, fluoride, and trihalomethane concentrations remained below MCLs during storage and recovery.Aquifer storage recovery (ASR) was tested in the Santee Limestone/Black Mingo Aquifer near Charleston, South Carolina, to assess the feasibility for subsurface storage of treated drinking water. Water quality data obtained during two representative ASR tests were interpreted to show three things: (1) recovery efficiency of ASR in this geological setting; (2) possible changes in physical characteristics of the aquifer during ASR testing; and (3) water quality changes and potability of recovered water during short (one- and six-day) storage durations in the predominantly

  8. Hydrogeology - MO 2014 Thermoclines Ozark Aquifer (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Ozark Aquifer thermo cline correlates the temperature data throughout the state in the Ordovician System and the Upper Cambrian Series, consisting of the Eminence...

  9. Aquifer vulnerability for Colorado and New Mexico

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey Data Series provides raster data representing an estimate of aquifer vulnerability calculated for each 30-meter raster cell. Depth to...

  10. Arsenic release from shallow aquifers of the Hetao basin, Inner Mongolia: evidence from bacterial community in aquifer sediments and groundwater.

    Science.gov (United States)

    Li, Yuan; Guo, Huaming; Hao, Chunbo

    2014-12-01

    Indigenous microbes play crucial roles in arsenic mobilization in high arsenic groundwater systems. Databases concerning the presence and the activity of microbial communities are very useful in evaluating the potential of microbe-mediated arsenic mobilization in shallow aquifers hosting high arsenic groundwater. This study characterized microbial communities in groundwaters at different depths with different arsenic concentrations by DGGE and one sediment by 16S rRNA gene clone library, and evaluated arsenic mobilization in microcosm batches with the presence of indigenous bacteria. DGGE fingerprints revealed that the community structure changed substantially with depth at the same location. It indicated that a relatively higher bacterial diversity was present in the groundwater sample with lower arsenic concentration. Sequence analysis of 16S rRNA gene demonstrated that the sediment bacteria mainly belonged to Pseudomonas, Dietzia and Rhodococcus, which have been widely found in aquifer systems. Additionally, NO3(-)-reducing bacteria Pseudomonas sp. was the largest group, followed by Fe(III)-reducing, SO4(2-)-reducing and As(V)-reducing bacteria in the sediment sample. These anaerobic bacteria used the specific oxyanions as electron acceptor and played a significant role in reductive dissolution of Fe oxide minerals, reduction of As(V), and release of arsenic from sediments into groundwater. Microcosm experiments, using intact aquifer sediments, showed that arsenic release and Fe(III) reduction were microbially mediated in the presence of indigenous bacteria. High arsenic concentration was also observed in the batch without amendment of organic carbon, demonstrating that the natural organic matter in sediments was the potential electron donor for microbially mediated arsenic release from these aquifer sediments.

  11. Transport of nonlinearly biodegradable contaminants in aquifers

    OpenAIRE

    Keijzer, H.

    2001-01-01

    This thesis deals with the transport behavior of nonlinearly biodegradable contaminants in aquifers. Such transport occurs during in situ bioremediation which is based on the injection of an electron acceptor or electron donor. The main interests in this thesis are the mutual influences of underlying processes, i.e. transport, adsorption and biodegradation, and their influence on in situ bioremediation performance. To gain insight in these influences, the processes in a homogeneous aquifer ar...

  12. Aquifer performance under the Mactaquac Dam

    Energy Technology Data Exchange (ETDEWEB)

    Tawil, A.H. [Acres International, Niagara Falls, ON (Canada); Harriman, F.B. [New Brunswick Power, Fredericton, NB (Canada)

    2001-10-01

    The highest dam in the whole of the Maritimes and New Brunswick in particular is the Mactaquac Dam, with a height of 58 m above the foundation. It forms an integral part of the Mactaquac Hydroelectric Development and the construction of the dam was completed in 1967. Composed of a central core of clay till and external shells of rockfill, it is a zoned embankment. The high artesian pressure rising 6 m above the Saint John River dominates, and the foundation under the dam is composed of a stratum of stiff glacial till underlain with a thick, water bearing aquifer. The aquifer needed to be depressurized during the construction phase and in the long term, and special measures were required to accomplish this. Measurements obtained over a period exceeding 30 years were used to describe the performance of the aquifer, which is discussed in this presentation. A continuous reduction in the yield from the six permanent relief wells in the aquifer was indicated by the instrumentation data. The outflow from the wells diminished by two-thirds over the thirty-four years since first filling the reservoir. The piezometric pressure in the aquifer remained constant over the same period. The sparse results of a two-hour pump test had formed the basis for the design decision not to install a costly foundation seepage cut-off to bedrock, as the conclusions drawn from the pump test were that the aquifer was hydrogeologically confined. 3 refs., 4 tabs., 9 figs.

  13. Simulation of a long-term aquifer test conducted near the Rio Grande, Albuquerque, New Mexico

    Science.gov (United States)

    McAda, Douglas P.

    2001-01-01

    A long-term aquifer test was conducted near the Rio Grande in Albuquerque during January and February 1995 using 22 wells and piezometers at nine sites, with the City of Albuquerque Griegos 1 production well as the pumped well. Griegos 1 discharge averaged about 2,330 gallons per minute for 54.4 days. A three-dimensional finite-difference ground-water-flow model was used to estimate aquifer properties in the vicinity of the Griegos well field and the amount of infiltration induced into the aquifer system from the Rio Grande and riverside drains as a result of pumping during the test. The model was initially calibrated by trial-and-error adjustments of the aquifer properties. The model was recalibrated using a nonlinear least-squares regression technique. The aquifer system in the area includes the middle Tertiary to Quaternary Santa Fe Group and post-Santa Fe Group valley- and basin-fill deposits of the Albuquerque Basin. The Rio Grande and adjacent riverside drains are in hydraulic connection with the aquifer system. The hydraulic-conductivity values of the upper part of the Santa Fe Group resulting from the model calibrated by trial and error varied by zone in the model and ranged from 12 to 33 feet per day. The hydraulic conductivity of the inner-valley alluvium was 45 feet per day. The vertical to horizontal anisotropy ratio was 1:140. Specific storage was 4 x 10-6 per foot of aquifer thickness, and specific yield was 0.15 (dimensionless). The sum of squared errors between the observed and simulated drawdowns was 130 feet squared. Not all aquifer properties could be estimated using nonlinear regression because of model insensitivity to some aquifer properties at observation locations. Hydraulic conductivity of the inner-valley alluvium, middle part of the Santa Fe Group, and riverbed and riverside-drain bed and specific yield had low sensitivity values and therefore could not be estimated. Of the properties estimated, hydraulic conductivity of the upper part of

  14. Digital data sets that describe aquifer characteristics of the Elk City Aquifer in western Oklahoma

    Science.gov (United States)

    Becker, C.J.; Runkle, D.L.; Rea, Alan

    1997-01-01

    ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Elk City aquifer in western Oklahoma. The aquifer covers an area of approximately 193,000 acres and supplies ground water for irrigation, domestic, and industrial purposes in Beckham, Custer, Roger Mills, and Washita Counties along the divide between the Washita and Red River basins. The Elk City aquifer consists of the Elk City Sandstone and overlying terrace deposits, made up of clay, silt, sand and gravel, and dune sands in the eastern part and sand and gravel of the Ogallala Formation (or High Plains aquifer) in the western part of the aquifer. The Elk City aquifer is unconfined and composed of very friable sandstone, lightly cemented with clay, calcite, gypsum, or iron oxide. Most of the grains are fine-sized quartz but the grain size ranges from clay to cobble in the aquifer. The Doxey Shale underlies the Elk City aquifer and acts as a confining unit, restricting the downward movement of ground water. All of the data sets were digitized and created from information and maps in a ground-water modeling thesis and report of the Elk City aquifer. The maps digitized were published at a scale of 1:63,360. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  15. Radial Dupuit interface flow to assess the aquifer storage and recovery potential of saltwater aquifers

    NARCIS (Netherlands)

    Bakker, M.

    2009-01-01

    A new accurate numerical solution is presented for aquifer storage and recovery (ASR) systems in coastal aquifers; flow is approximated as radial Dupuit interface flow. The radial velocities of points on the interface are a function of time, the vertical coordinate, and the dimensionless parameter D

  16. Aquifer Storage Recovery (ASR) of chlorinated municipal drinking water in a confined aquifer

    Science.gov (United States)

    Izbicki, John A.; Petersen, Christen E.; Glotzbach, Kenneth J.; Metzger, Loren F.; Christensen, Allen H.; Smith, Gregory A.; O'Leary, David R.; Fram, Miranda S.; Joseph, Trevor; Shannon, Heather

    2010-01-01

    About 1.02 x 106 m3 of chlorinated municipal drinking water was injected into a confined aquifer, 94-137 m below Roseville, California, between December 2005 and April 2006. The water was stored in the aquifer for 438 days, and 2.64 x 106 m3 of water were extracted between July 2007 and February 2008. On the basis of Cl data, 35% of the injected water was recovered and 65% of the injected water and associated disinfection by-products (DBPs) remained in the aquifer at the end of extraction. About 46.3 kg of total trihalomethanes (TTHM) entered the aquifer with the injected water and 37.6 kg of TTHM were extracted. As much as 44 kg of TTHMs remained in the aquifer at the end of extraction because of incomplete recovery of injected water and formation of THMs within the aquifer by reactions with freechlorine in the injected water. Well-bore velocity log data collected from the Aquifer Storage Recovery (ASR) well show as much as 60% of the injected water entered the aquifer through a 9 m thick, high-permeability layer within the confined aquifer near the top of the screened interval. Model simulations of ground-water flow near the ASR well indicate that (1) aquifer heterogeneity allowed injected water to move rapidly through the aquifer to nearby monitoring wells, (2) aquifer heterogeneity caused injected water to move further than expected assuming uniform aquifer properties, and (3) physical clogging of high-permeability layers is the probable cause for the observed change in the distribution of borehole flow. Aquifer heterogeneity also enhanced mixing of native anoxic ground water with oxic injected water, promoting removal of THMs primarily through sorption. A 3 to 4-fold reduction in TTHM concentrations was observed in the furthest monitoring well 427 m downgradient from the ASR well, and similar magnitude reductions were observed in depth-dependent water samples collected from the upper part of the screened interval in the ASR well near the end of the extraction

  17. A dynamic perennial firn aquifer

    Science.gov (United States)

    Kohler, J.; Christianson, K.; van Pelt, W. J. J.

    2015-12-01

    Ice-penetrating radar and GPS observations are used to reveal a perennial firn aquifer (PFA) on a high icefield in Svalbard. This PFA appears to be fully analogous to those found in Greenland. A bright, widespread radar reflector separates relatively dry and water-saturated firn. This surface, the phreatic firn water table, is deeper beneath local surface elevation maxima, shallower in surface lows, and steeper where the surface is steep. The PFA is recharged by downward percolation of near-surface meltwater, and drained by flow subparallel to ice flow and the glacier surface. The water table of the PFA rises with increasing meltwater supply during summer, especially during warm years, and drops during winter. The reflector cross-cuts snow stratigraphy; we use the apparent deflection of accumulation layers due to the higher dielectric permittivity below the water table to infer that the firn pore space becomes progressively more saturated as depth increases. Radar data collected over several years indicate that the PFA responds rapidly (sub-annually) to the surface melt forcing. We use a coupled surface energy-balance and firn model, forced with from regional climate model data for the years 1961-2012, to estimate the amount of retained surface melt available to recharge the PFA. Results suggest that the water amount flowing into and out of the PFA is substantial, such that the PFA is capable of providing significant input to the englacial hydrology system.

  18. Review of Aquifer Storage and Recovery Performance in the Upper Floridan Aquifer in Southern Florida

    Science.gov (United States)

    Reese, Ronald S.

    2006-01-01

    Introduction: Interest and activity in aquifer storage and recovery (ASR) in southern Florida has increased greatly during the past 10 to 15 years. ASR wells have been drilled to the carbonate Floridan aquifer system at 30 sites in southern Florida, mostly by local municipalities or counties located in coastal areas. The primary storage zone at these sites is contained within the brackish to saline Upper Floridan aquifer of the Floridan aquifer system. The strategy for use of ASR in southern Florida is to store excess freshwater available during the wet season in an aquifer and recover it during the dry season when needed for supplemental water supply. Each ASR cycle is defined by three periods: recharge, storage, and recovery. This fact sheet summarizes some of the findings of a second phase retrospective assessment of existing ASR facilities and sites.

  19. Multidepth pumping tests in deep aquifers.

    Science.gov (United States)

    Alam, N; Olsthoorn, T N

    2014-09-01

    Multidepth pumping tests (MDPTs), in which different sections of a screen are pumped in sequence, are not being used by hydrogeologists, despite the capability of such tests to resolve uncertainties in the estimation of aquifer characteristics. MDPTs can be used to discern the effects of partial penetration and vertical anisotropy. This article demonstrates the use of MDPTs for a deep and vertically anisotropic aquifer, based on a real and unique series of pumping tests conducted in the Indus Basin. Traditional single-layer methods, which incorporate partial penetration and vertical scaling, were employed to evaluate these tests. However, the drawdowns of the 19 piezometers at different depths for which times series data were available could not be matched, presumably because of the layered structure of the aquifer. Numerical (MODFLOW) and multilayer analytical (Hemker and Maas 1987; Hemker 1999) approaches were used to assess the benefits of using MDPTs in the analysis of deep layered and anisotropic aquifers. The multilayer analytical solution results are consistent with the measured and numerically computed drawdowns. The original step-drawdown data were used to verify the model independently. The results of statistical analyses indicate that the parameters for a three-layer system are uniquely estimated. A sensitivity analysis showed that aquifer depths greater than 900 m do not affect the drawdown. The multilayer analytical solution was implemented in MATLAB and can be found in the online version of this article. This multilayer analytical approach was implemented in MLU by Hemker and Randall (2013) for up to 40 layers. The results of this study will be useful in groundwater management, exploration, and optimal well depth estimation for the Indus Basin aquifer and other vertically heterogeneous aquifers.

  20. Stochastic analysis of virus transport in aquifers

    Science.gov (United States)

    Campbell, Rehmann L.L.; Welty, C.; Harvey, R.W.

    1999-01-01

    A large-scale model of virus transport in aquifers is derived using spectral perturbation analysis. The effects of spatial variability in aquifer hydraulic conductivity and virus transport (attachment, detachment, and inactivation) parameters on large-scale virus transport are evaluated. A stochastic mean model of virus transport is developed by linking a simple system of local-scale free-virus transport and attached-virus conservation equations from the current literature with a random-field representation of aquifer and virus transport properties. The resultant mean equations for free and attached viruses are found to differ considerably from the local-scale equations on which they are based and include effects such as a free-virus effective velocity that is a function of aquifer heterogeneity as well as virus transport parameters. Stochastic mean free-virus breakthrough curves are compared with local model output in order to observe the effects of spatial variability on mean one-dimensional virus transport in three-dimensionally heterogeneous porous media. Significant findings from this theoretical analysis include the following: (1) Stochastic model breakthrough occurs earlier than local model breakthrough, and this effect is most pronounced for the least conductive aquifers studied. (2) A high degree of aquifer heterogeneity can lead to virus breakthrough actually preceding that of a conservative tracer. (3) As the mean hydraulic conductivity is increased, the mean model shows less sensitivity to the variance of the natural-logarithm hydraulic conductivity and mean virus diameter. (4) Incorporation of a heterogeneous colloid filtration term results in higher predicted concentrations than a simple first-order adsorption term for a given mean attachment rate. (5) Incorporation of aquifer heterogeneity leads to a greater range of virus diameters for which significant breakthrough occurs. (6) The mean model is more sensitive to the inactivation rate of viruses

  1. A Black Hills-Madison Aquifer origin for Dakota Aquifer groundwater in northeastern Nebraska.

    Science.gov (United States)

    Stotler, Randy; Harvey, F Edwin; Gosselin, David C

    2010-01-01

    Previous studies of the Dakota Aquifer in South Dakota attributed elevated groundwater sulfate concentrations to Madison Aquifer recharge in the Black Hills with subsequent chemical evolution prior to upward migration into the Dakota Aquifer. This study examines the plausibility of a Madison Aquifer origin for groundwater in northeastern Nebraska. Dakota Aquifer water samples were collected for major ion chemistry and isotopic analysis ((18)O, (2)H, (3)H, (14)C, (13)C, (34)S, (18)O-SO(4), (87)Sr, (37)Cl). Results show that groundwater beneath the eastern, unconfined portion of the study area is distinctly different from groundwater sampled beneath the western, confined portion. In the east, groundwater is calcium-bicarbonate type, with delta(18)O values (-9.6 per thousand to -12.4 per thousand) similar to local, modern precipitation (-7.4 per thousand to -10 per thousand), and tritium values reflecting modern recharge. In the west, groundwater is calcium-sulfate type, having depleted delta(18)O values (-16 per thousand to -18 per thousand) relative to local, modern precipitation, and (14)C ages 32,000 to more than 47,000 years before present. Sulfate, delta(18)O, delta(2)H, delta(34)S, and delta(18)O-SO(4) concentrations are similar to those found in Madison Aquifer groundwater in South Dakota. Thus, it is proposed that Madison Aquifer source water is also present within the Dakota Aquifer beneath northeastern Nebraska. A simple Darcy equation estimate of groundwater velocities and travel times using reported physical parameters from the Madison and Dakota Aquifers suggests such a migration is plausible. However, discrepancies between (14)C and Darcy age estimates indicate that (14)C ages may not accurately reflect aquifer residence time, due to mixtures of varying aged water.

  2. Vertical Gradients in Water Chemistry and Age in the Northern High Plains Aquifer, Nebraska, 2003

    Science.gov (United States)

    McMahon, P.B.; Böhlke, J.K.; Carney, C.P.

    2007-01-01

    clay-mineral precipitation; organic-carbon and pyrite oxidation; oxygen reduction and denitrification; and cation exchange. Mixing with surface water affected the chemistry of ground water in alluvial sediments of the Platte River Valley. Radiocarbon ages in the aquifer, adjusted for carbon mass transfers, ranged from 1,800 to 15,600 14C years before present. These results have important implications with respect to development of ground-water resources in the Sand Hills. Most of the water in the aquifer predates modern anthropogenic activity so excessive removal of water by pumping is not likely to be replenished by natural recharge in a meaningful timeframe. Vertical gradients in ground-water age were used to estimate long-term average recharge rates in the aquifer. In most areas, the recharge rates ranged from 0.02 to 0.05 foot per year. The recharge rate was 0.2 foot per year in one part of the aquifer characterized by large downward hydraulic gradients. Nitrite plus nitrate concentrations at the water table were 0.13 to 3.13 milligrams per liter as nitrogen, and concentrations substantially decreased with depth in the aquifer. Dissolved- gas and nitrogen-isotope data indicate that denitrification in the aquifer removed 0 to 97 percent (average = 50 percent) of the nitrate originally present in recharge. The average amount of nitrate removed by denitrification in the aquifer north of the Platte River (Sand Hills) was substantially greater than the amount removed south of the river (66 as opposed to 0 percent), and the extent of nitrate removal appears to be related to the presence of thick deposits of sediment on top of the Ogallala Group in the Sand Hills that contained electron donors, such as organic carbon and pyrite, to support denitrification. Apparent rates of dissolved-oxygen reduction and denitrification were estimated on the basis of decreases in dissolved- oxygen concentrations and increases in concentrations of excess nitrogen gas and ground-

  3. Potentiometric surfaces in the Cockfield and Wilcox aquifers of southern and northeastern Arkansas, 2003

    Science.gov (United States)

    Yeatts, Daniel S.

    2004-01-01

    This report presents the results of water-level measurements made at wells in the Cockfield Formation and Wilcox Group of southern and northeastern Arkansas during 2003, and the water levels are displayed in potentiometric-surface maps and hydrographs. During March and April 2003, the water level was measured at 55 wells completed in the Cockfield aquifer, 13 wells completed in the Wilcox aquifer of southern Arkansas, and 43 wells completed in the Wilcox aquifer of northeastern Arkansas. The Cockfield Formation generally consists of discontinuous sand units interbedded with silt, clay, and lignite in southeastern Arkansas. Sand beds near the base of the Cockfield Formation constitute most of the Cockfield aquifer. Withdrawals from the Cockfield aquifer in the study area during 2000 totaled about 9 million gallons per day. The potentiometric surface of the Cockfield aquifer constructed from the 2003 water levels shows that regional direction of ground-water flow generally is towards the east and southeast, away from the outcrop, except in areas of intense ground-water withdrawals. Some local ground-water flow in the outcrop area is toward rivers that have eroded into the Cockfield Formation and deposited alluvium in south Bradley and Calhoun Counties (Ouachita River), and in north Dallas County (Saline River). An evaluation of 20 wells with water-level data from 1983 to 2003 shows that water levels in 15 wells have declined at a rate of -0.04 to -0.97 feet per year, and water levels in 5 wells have risen at a rate of 0.07 to 0.32 feet per year. An evaluation of the same 20 wells from 2000 to 2003 shows that water levels have declined in only 8 wells, and water levels have risen in 12 wells. The Wilcox Group is distributed throughout most of southern and eastern Arkansas. There are two study areas in southern and northeastern Arkansas. The Wilcox Group of the southern study area consists of interbedded clay, sandy clay, sand, and lignite. Thin discontinuous sand

  4. Groundwater vulnerability mapping of Qatar aquifers

    Science.gov (United States)

    Baalousha, Husam Musa

    2016-12-01

    Qatar is one of the most arid countries in the world with limited water resources. With little rainfall and no surface water, groundwater is the only natural source of fresh water in the country. Whilst the country relies mainly on desalination of seawater to secure water supply, groundwater has extensively been used for irrigation over the last three decades, which caused adverse environmental impact. Vulnerability assessment is a widely used tool for groundwater protection and land-use management. Aquifers in Qatar are carbonate with lots of fractures, depressions and cavities. Karst aquifers are generally more vulnerable to contamination than other aquifers as any anthropogenic-sourced contaminant, especially above a highly fractured zone, can infiltrate quickly into the aquifer and spread over a wide area. The vulnerability assessment method presented in this study is based on two approaches: DRASTIC and EPIK, within the framework of Geographical Information System (GIS). Results of this study show that DRASTIC vulnerability method suits Qatar hydrogeological settings more than EPIK. The produced vulnerability map using DRASTIC shows coastal and karst areas have the highest vulnerability class. The southern part of the country is located in the low vulnerability class due to occurrence of shale formation within aquifer media, which averts downward movement of contaminants.

  5. Hydrogeology and predevelopment flow in the Texas Gulf Coast aquifer systems

    Science.gov (United States)

    Ryder, Paul D.

    1988-01-01

    A multilayered ground-water flow system exists in the Coastal Plain sediments of Texas. The Tertiary and Quaternary clastic deposits have an area! extent of 128,000 square miles onshore and in the Gulf of Mexico. Two distinct aquifer systems are recognized for the sediments, which range in thickness from a few feet to more than 12,000 feet. The older system the Texas coastal uplands aquifer system consists of four aquifers and two confining units in the Wilcox and Claiborne Groups. It is bounded from below by the practically impermeable Midway confining unit or by the top of the geopressured zone. It is bounded from above by the poorly permeable Vicksburg-Jackson confining unit, which separates it from the younger coastal lowlands aquifer system. The coastal lowlands aquifer system consists of five permeable zones and two confining units that range in age from Oligocene to Holocene. The hydrogeologic units of both systems are exposed in bands that parallel the coastline. The units dip and thicken toward the Gulf.

  6. Semianalytical Solutions for Transport in Aquifer and Fractured Clay Matrix System

    Science.gov (United States)

    A three-dimensional mathematical model that describes transport of contaminant in a horizontal aquifer with simultaneous diffusion into a fractured clay formation is proposed. A group of analytical solutions is derived based on specific initial and boundary conditions as well as ...

  7. Aquifers of Alluvial and Glacial Origin - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the alluvial and glacial aquifers north of the southern-most line of glaciation. Aquifers are shown in the States of Maine,...

  8. Snake River Plain Basin-fill aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Snake River Plain aquifer system, which includes both the basaltic and basin-fill aquifers. This dataset does not...

  9. Water-level change, High Plains aquifer, 1980 to 1995

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1980 to 1995, in feet. The High Plains aquifer underlies...

  10. Water-level change, High Plains aquifer, 1995 to 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1995 to 2000, in feet. The High Plains aquifer underlies...

  11. Water-level change, High Plains aquifer, 2005 to 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2005 to 2009, in feet. The High Plains aquifer underlies...

  12. Water-level change, High Plains aquifer, 2000 to 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2000 to 2005, in feet. The High Plains aquifer underlies...

  13. Groundwater Mounding in Non-uniform Aquifers with Implications for Managed Aquifer Recharge

    Science.gov (United States)

    Zlotnik, V. A.; Noel, P.; Kacimov, A. R.; Al Maktoumi, A. K.

    2015-12-01

    Many areas of the world (e.g. the Middle East and North Africa countries) are deficient in observation networks and hydrogeological data needed for Managed Aquifer Recharge (MAR) design. Therefore, diagnostic analytical approaches are appropriate for feasibility studies of MAR. It was found that the common assumption of aquifer thickness uniformity often does not hold, especially in mountainous watersheds. However, the only practical result available for non-uniform aquifers was developed for well hydraulics applications (point sinks or sources) by Hantush (1962), while the recharge zones may cover large areas on the scale of kilometers, such as temporarily filled impoundments (natural and engineered reservoirs in wadis, depressions, trenches, etc.) or perennial streams accepting massive treated wastewater discharge. To address these important, but overlooked MAR problems in sloping aquifers, a set of new closed-form analytical solutions for water table elevations were obtained. Interestingly, the 2D groundwater flow equation acquires the advection-dispersion equation form in these cases. The quadratures in closed-form solutions obtained by the Green's function method converge rapidly. These models account for both shapes and orientations of sources with respect to the direction of the aquifer base gradient. Qualitatively, solutions in sloping aquifers have an important trait: the mounding is limited in time and space, unlike in aquifers with a horizontal base. Aquifers with the greater slopes have the lesser potential of waterlogging from the rising water table and different storage characteristics (height and volume of locally stored water). Computational aspects of these solutions for MAR analyses are illustrated by example utilizing regional aquifer properties near Az Zarqa River, Jordan. (This study was supported by a grant from USAID-FABRI, project contract: AID-OAA-TO-11-00049, Subcontract: 1001624 -12S-19745).

  14. Genetic algorithms and aquifer parameter identification

    Institute of Scientific and Technical Information of China (English)

    LI Jing-sheng(李竞生); YAO Lei-hua(姚磊华); LI Yang(李杨)

    2003-01-01

    In order to identify aquifer parameter,authors develops an improved combinatorial method called best chromosome clone plus younger generation chromosome prepotency genetic algorithm (BCC-YGCP-GA), based on a decimal system simple genetic algorithm (SGA). The paper takes unsteady state flows in a two-dimensional, inhomogeneous, confined aquifer for a ideal model, and utilizes SGA and BCC-YGCP-GA coupled to finite element method for identifying aquifer hydraulic conductivity K1,K2,K3 and storage S1,S2,S3, respectively. It is shown from the result that GSA does not reach convergence with 100 generations, whereas convergence rate of BCC-YGCD-GA is very fast. Objective function value calculated by BCC-YGCD-GA is 0.001 29 with 100 generations, and hydraulic conductivity and storage of three zones are almost equal to the "true" values of ideal model.

  15. Aquifer thermal energy storage. International symposium: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    Aquifers have been used to store large quantities of thermal energy to supply process cooling, space cooling, space heating, and ventilation air preheating, and can be used with or without heat pumps. Aquifers are used as energy sinks and sources when supply and demand for energy do not coincide. Aquifer thermal energy storage may be used on a short-term or long-term basis; as the sole source of energy or as a partial storage; at a temperature useful for direct application or needing upgrade. The sources of energy used for aquifer storage are ambient air, usually cold winter air; waste or by-product energy; and renewable energy such as solar. The present technical, financial and environmental status of ATES is promising. Numerous projects are operating and under development in several countries. These projects are listed and results from Canada and elsewhere are used to illustrate the present status of ATES. Technical obstacles have been addressed and have largely been overcome. Cold storage in aquifers can be seen as a standard design option in the near future as it presently is in some countries. The cost-effectiveness of aquifer thermal energy storage is based on the capital cost avoidance of conventional chilling equipment and energy savings. ATES is one of many developments in energy efficient building technology and its success depends on relating it to important building market and environmental trends. This paper attempts to provide guidance for the future implementation of ATES. Individual projects have been processed separately for entry onto the Department of Energy databases.

  16. Ground-water quality assessment of the central Oklahoma Aquifer, Oklahoma; project description

    Science.gov (United States)

    Christenson, S.C.; Parkhurst, D.L.

    1987-01-01

    In April 1986, the U.S. Geological Survey began a pilot program to assess the quality of the Nation's surface-water and ground-water resources. The program, known as the National Water-Quality Assessment (NAWQA) program, is designed to acquire and interpret information about a variety of water-quality issues. The Central Oklahoma aquifer project is one of three ground-water pilot projects that have been started. The NAWQA program also incudes four surface-water pilot projects. The Central Oklahoma aquifer project, as part of the pilot NAWQA program, will develop and test methods for performing assessments of ground-water quality. The objectives of the Central Oklahoma aquifer assessment are: (1) To investigate regional ground-water quality throughout the aquifer in the manner consistent with the other pilot ground-water projects, emphasizing the occurrence and distribution of potentially toxic substances in ground water, including trace elements, organic compounds, and radioactive constituents; (2) to describe relations between ground-water quality, land use, hydrogeology, and other pertinent factors; and (3) to provide a general description of the location, nature, and possible causes of selected prevalent water-quality problems within the study unit; and (4) to describe the potential for water-quality degradation of ground-water zones within the study unit. The Central Oklahoma aquifer, which includes in descending order the Garber Sandstone and Wellington Formation, the Chase Group, the Council Grove Group, the Admire Group, and overlying alluvium and terrace deposits, underlies about 3,000 square miles of central Oklahoma and is used extensively for municipal, industrial, commercial, and domestic water supplies. The aquifer was selected for study by the NAWQA program because it is a major source for water supplies in central Oklahoma and because it has several known or suspected water-quality problems. Known problems include concentrations of arsenic, chromium

  17. Digital data sets that describe aquifer characteristics of the Vamoosa-Ada aquifer in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Vamoosa-Ada aquifer in east-central Oklahoma. The Vamoosa-Ada aquifer...

  18. Digital data sets that describe aquifer characteristics of the Vamoosa-Ada aquifer in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Vamoosa-Ada aquifer in east-central Oklahoma. The Vamoosa-Ada aquifer is an important...

  19. EPA Region 6 Sole Source Aquifers in Louisiana, Geographic NAD83, EPA (1996) [sole_source_aquifers_LA_EPA_1996

    Data.gov (United States)

    Louisiana Geographic Information Center — Polygon layer of EPA Region 6 sole source aquifers in Louisiana. The sole source aquifers represented are Chicot and Southern Hills in Louisiana/Mississippi.

  20. Digital data sets that describe aquifer characteristics of the Vamoosa-Ada aquifer in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant recharge values for the Vamoosa-Ada aquifer, in east-central Oklahoma. The Vamoosa-Ada aquifer is an...

  1. Predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This product "Predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area" is a 1:250,000-scale vector dataset...

  2. 40 CFR 146.4 - Criteria for exempted aquifers.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Criteria for exempted aquifers. 146.4... for exempted aquifers. An aquifer or a portion thereof which meets the criteria for an “underground source of drinking water” in § 146.3 may be determined under 40 CFR 144.8 to be an “exempted aquifer”...

  3. Review: The Yucatán Peninsula karst aquifer, Mexico

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Gondwe, Bibi Ruth Neuman; Charvet, Guillaume

    2011-01-01

    The Yucatán Peninsula karst aquifer is one of the most extensive and spectacular karst aquifer systems on the planet. This transboundary aquifer system extends over an area of approximately 165,000 km2 in México, Guatemala and Belize. The Triassic to Holocene Yucatán limestone platform is located...

  4. Cold water aquifer storage. [air conditioning

    Science.gov (United States)

    Reddell, D. L.; Davison, R. R.; Harris, W. B.

    1980-01-01

    A working prototype system is described in which water is pumped from an aquifer at 70 F in the winter time, chilled to a temperature of less than 50 F, injected into a ground-water aquifer, stored for a period of several months, pumped back to the surface in the summer time. A total of 8.1 million gallons of chilled water at an average temperature of 48 F were injected. This was followed by a storage period of 100 days. The recovery cycle was completed a year later with a total of 8.1 million gallons recovered. Approximately 20 percent of the chill energy was recovered.

  5. In situ microcosms in aquifer bioremediation studies.

    Science.gov (United States)

    Mandelbaum, R T; Shati, M R; Ronen, D

    1997-07-01

    The extent to which aquifer microbiota can be studied under laboratory or simulated conditions is limited by our inability to authentically duplicate natural conditions in the laboratory. Therefore, extrapolation of laboratory results to real aquifer situations is often criticized, unless validation of the data is performed in situ. Reliable data acquisition is critical for the estimation of chemical and biological reaction rates of biodegradation processes in groundwater and as input data for mathematical models. Typically, in situ geobiochemical studies relied on the injection of groundwater spiked with compounds or bacteria of interest into the aquifer, followed by monitoring the changes over time and space. In situ microcosms provide a more confined study site for measurements of microbial reactions, yet closer to natural conditions than laboratory microcosms. Two basic types of in situ aquifer microcosm have been described in recent years, and both originated from in situ instruments initially designed for geochemical measurements. Gillham et al. [Ground Water 28 (1990) 858-862] constructed an instrument that isolates a portion of an aquifer for in situ biochemical rate measurements. More recently Shati et al. [Environ. Sci. Technol. 30 (1996) 2646-2653] modified a multilayer sampler for studying the activity of inoculated bacteria in a contaminated aquifer Keeping in mind recent advances in environmental microbiology methodologies such as immunofluorescence direct counts, oligonucleotide and PCR probes, fatty acid methyl esther analysis for the detection and characterization of bacterial communities, measurement of mRNA and expression of proteins, it is evident that much new information can now be gained from in situ work. Using in situ microcosms to study bioremediation efficiencies, the fate of introduced microorganisms and general geobiochemical aquifer processes can shed more realistic light on the microbial underworld. The aim of this paper is to

  6. Diversity of methanotroph communities in a basalt aquifer.

    Science.gov (United States)

    Newby, D T; Reed, D W; Petzke, L M; Igoe, A L; Delwiche, M E; Roberto, F F; McKinley, J P; Whiticar, M J; Colwell, F S

    2004-06-01

    Methanotrophic bacteria play an important role in global cycling of carbon and co-metabolism of contaminants. Methanotrophs from pristine regions of the Snake River Plain Aquifer (SRPA; Idaho, USA) were studied in order to gain insight into the native groundwater communities' genetic potential to carry out TCE co-metabolism. Wells were selected that were proximal to a TCE plume believed to be undergoing natural attenuation. Methane concentrations ranged from 1 to >1000 nM. Carbon isotope ratios and diversity data together suggest that the SRPA contains active communities of methanotrophs that oxidize microbially produced methane. Microorganisms removed from groundwater by filtration were used as inocula for enrichments or frozen immediately and DNA was subsequently extracted for molecular characterization. Primers that specifically target methanotroph 16S rRNA genes or genes that code for subunits of soluble or particulate methane monooxygenase, mmoX and pmoA, respectively, were used to characterize the indigenous methanotrophs via PCR, cloning, RFLP analysis, and sequencing. Type I methanotroph clones aligned with Methylomonas, Methylocaldum, and Methylobacter sequences and a distinct 16S rRNA phylogenetic lineage grouped near Methylobacter. The majority of clone sequences in type II methanotroph 16S rRNA, pmoA, and mmoX gene libraries grouped closely with sequences in the Methylocystis genus. A subset of the type II methanotroph clones from the aquifer had sequences that aligned most closely to Methylosinus trichosporium OB3b and Methylocystis spp., known TCE-co-metabolizing methanotrophs.

  7. Ground-water-quality assessment of the Central Oklahoma Aquifer, Oklahoma; geochemical and geohydrologic investigations

    Science.gov (United States)

    Parkhurst, D.L.; Christenson, S.C.; Breit, G.N.

    1993-01-01

    The National Water-Quality Assessment pilot project for the Central Oklahoma aquifer examined the chemical and isotopic composition of ground water, the abundances and textures of minerals in core samples, and water levels and hydraulic properties in the flow system to identify geochemical reactions occurring in the aquifer and rates and directions of ground-water flow. The aquifer underlies 3,000\\x11square miles of central Oklahoma and consists of Permian red beds, including parts of the Permian Garber Sandstone, Wellington Formation, and Chase, Council Grove, and Admire Groups, and Quaternary alluvium and terrace deposits. In the part of the Garber Sandstone and Wellington Formation that is not confined by the Permian Hennessey Group, calcium, magnesium, and bicarbonate are the dominant ions in ground water; in the confined part of the Garber Sandstone and Wellington Formation and in the Chase, Council Grove, and Admire Groups, sodium and bicarbonate are the dominant ions in ground water. Nearly all of the Central Oklahoma aquifer has an oxic or post-oxic environment as indicated by the large dissolved concentrations of oxygen, nitrate, arsenic (V), chromium (VI), selenium (VI), vanadium, and uranium. Sulfidic and methanic environments are virtually absent. Petrographic textures indicate dolomite, calcite, sodic plagioclase, potassium feldspars, chlorite, rock fragments, and micas are dissolving, and iron oxides, manganese oxides, kaolinite, and quartz are precipitating. Variations in the quantity of exchangeable sodium in clays indicate that cation exchange is occurring within the aquifer. Gypsum may dissolve locally within the aquifer, as indicated by ground water with large concentrations of sulfate, but gypsum was not observed in core samples. Rainwater is not a major source for most elements in ground water, but evapotranspiration could cause rainwater to be a significant source of potassium, sulfate, phosphate and nitrogen species. Brines derived from

  8. Nitrogen cycling within an alluvial aquifer during groundwater fluctuations

    Science.gov (United States)

    Bouskill, N.; Conrad, M. E.; Bill, M.; Brodie, E.; Forbes, M. S.; Casciotti, K. L.; Williams, K. H.

    2015-12-01

    Subsurface terrestrial-aquatic interfaces are hotspots of biogeochemical cycling of terrestrially derived organic matter and nutrients. However, pathways of nitrogen (N) loss within subsurface aquifers are poorly understood. Here we take an experimental and mechanistic modeling approach to gauge the contribution of different microbial functional groups to the transformation and loss of N in an unconfined aquifer at Rifle, Colorado. During 2014 we measured nitrate (NO3), ammonia, gaseous nitrous oxide (N2O) and the corresponding isotopic composition of NO3 and N2O. Coincident with an annual Spring/ Summer excursion in groundwater elevation, we observed a rapid decline in NO3 concentrations at three discrete depths (2, 2.5 and 3 m) within the aquifer. Isotopic measurements (i.e., δ18O and δ15N) of NO3 suggest an immediate onset of biological N loss at 2 m, but not at 3 m where the isotopic composition demonstrated dilution of NO3 concentration prior to the onset of biological N loss. This implies that the groundwater becomes increasingly anoxic as it rises within the capillary fringe. We observed the highest rates of N2O production concomitant with the largest enrichment of the δ18ONO3 and δ15NNO3 isotopes. A mechanistic microbial model representing the diverse physiology of nitrifiers, aerobic and anaerobic (denitrifying) heterotrophs and anammox bacteria indicates that the bulk of N2O production and N loss is attributable to denitrifying heterotrophs. However, this relationship is dependent on the coupling between aerobic and anaerobic microbial guilds at the oxic-anoxic interface. Modeling results suggest anammox plays a more prominent role in N loss under conditions where the organic matter input is low and rapidly drawn down by aerobic heterotrophs prior to the rise of the water table. We discuss our modeling results in light of recent molecular microbiology work at this site, but also with respect to implications for N loss across terrestrial

  9. Aquifer geochemistry at potential aquifer storage and recovery sites in coastal plain aquifers in the New York city area, USA

    Science.gov (United States)

    Brown, C.J.; Misut, P.E.

    2010-01-01

    The effects of injecting oxic water from the New York city (NYC) drinking-water supply and distribution system into a nearby anoxic coastal plain aquifer for later recovery during periods of water shortage (aquifer storage and recovery, or ASR) were simulated by a 3-dimensional, reactive-solute transport model. The Cretaceous aquifer system in the NYC area of New York and New Jersey, USA contains pyrite, goethite, locally occurring siderite, lignite, and locally varying amounts of dissolved Fe and salinity. Sediment from cores drilled on Staten Island and western Long Island had high extractable concentrations of Fe, Mn, and acid volatile sulfides (AVS) plus chromium-reducible sulfides (CRS) and low concentrations of As, Pb, Cd, Cr, Cu and U. Similarly, water samples from the Lloyd aquifer (Cretaceous) in western Long Island generally contained high concentrations of Fe and Mn and low concentrations of other trace elements such as As, Pb, Cd, Cr, Cu and U, all of which were below US Environmental Protection Agency (USEPA) and NY maximum contaminant levels (MCLs). In such aquifer settings, ASR operations can be complicated by the oxidative dissolution of pyrite, low pH, and high concentrations of dissolved Fe in extracted water.The simulated injection of buffered, oxic city water into a hypothetical ASR well increased the hydraulic head at the well, displaced the ambient groundwater, and formed a spheroid of injected water with lower concentrations of Fe, Mn and major ions in water surrounding the ASR well, than in ambient water. Both the dissolved O2 concentrations and the pH of water near the well generally increased in magnitude during the simulated 5-a injection phase. The resultant oxidation of Fe2+ and attendant precipitation of goethite during injection provided a substrate for sorption of dissolved Fe during the 8-a extraction phase. The baseline scenario with a low (0.001M) concentration of pyrite in aquifer sediments, indicated that nearly 190% more water

  10. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of a constant hydraulic conductivity value for the Central Oklahoma aquifer in central Oklahoma. This area encompasses...

  11. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Central Oklahoma aquifer in central Oklahoma. This area encompasses all or part of...

  12. Digital data sets that describe aquifer characteristics of the Central Oklahoma aquifer in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of a constant recharge value for the Central Oklahoma aquifer in central Oklahoma. This area encompasses all or part of...

  13. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of a digitized polygon of a constant recharge value for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace...

  14. Digital data sets that describe aquifer characteristics of the Rush Springs aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Rush Springs aquifer in western Oklahoma. This area encompasses all or...

  15. Aquifer Boundary of the Wood River Valley Aquifer System, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains the boundary of the Wood River Valley aquifer system as modified and expanded from that defined by Skinner and others (2007): It has been...

  16. Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant recharge values for the Antlers aquifer in southeastern Oklahoma. The Early Cretaceous-age Antlers Sandstone...

  17. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant hydraulic conductivity values for the High Plains aquifer in Oklahoma. This area encompasses the panhandle...

  18. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant recharge rates for the High Plains aquifer in Oklahoma. This area encompasses the panhandle counties of...

  19. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid...

  20. Digital data sets that describe aquifer characteristics of the High Plains aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the High Plains aquifer in western Oklahoma. This area encompasses the panhandle counties of...

  1. Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of a constant hydraulic conductivity value for the Antlers aquifer in southeastern Oklahoma. The Early Cretaceous-age...

  2. Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Antlers aquifer in southeastern Oklahoma. The Early Cretaceous-age Antlers Sandstone is an...

  3. Can Remote Sensing Detect Aquifer Characteristics?: A Case Study in the Guarani Aquifer System

    Science.gov (United States)

    Richey, A. S.; Thomas, B.; Famiglietti, J. S.

    2013-12-01

    Global water supply resiliency depends on groundwater, especially regions threatened by population growth and climate change. Aquifer characteristics, even as basic as confined versus unconfined, are necessary to prescribe regulations to sustainably manage groundwater supplies. A significant barrier to sustainable groundwater management exists in the difficulties associated with mapping groundwater resources and characteristics at a large spatial scale. This study addresses this challenge by investigating if remote sensing, including with NASA's Gravity Recovery and Climate Experiment (GRACE), can detect and quantify key aquifer parameters and characteristics. We explore this through a case study in the Guarani Aquifer System (GAS) of South America, validating our remote sensing-based findings against the best available regional estimates. The use of remote sensing to advance the understanding of large aquifers is beneficial to sustainable groundwater management, especially in a trans-boundary system, where consistent information exchange can occur within hydrologic boundaries instead of political boundaries.

  4. Digital data sets that describe aquifer characteristics of the Rush Springs aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant recharge values for the Rush Springs aquifer in western Oklahoma. This area encompasses all or part of...

  5. Digital data sets that describe aquifer characteristics of the Rush Springs aquifer in western Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Rush Springs aquifer in western Oklahoma. This area encompasses all or part of Blaine,...

  6. State Aquifer Recharge Atlas Plates, Geographic NAD83, LDEQ (1999) [aquifer_recharge_potential_LDEQ_1988

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a polygon dataset depicting the boundaries of aquifer systems in the state of Louisiana and adjacent areas of Texas, Arkansas and a portion of Mississippi....

  7. Hydrogeochemical Analysis of an Overexploited Aquifer In Bangladesh Toward Managed Aquifer Recharge Project Implementation

    Science.gov (United States)

    Rahman, M. A.; Wiegand, B. A.; Pervin, M.; Sauter, M.

    2012-12-01

    In most parts of the upper Dupitila aquifer (Dhaka City, Bangladesh) the average groundwater depletion reaches 2-3 m/year due to increasing water demands of the growing population. To counteract overexploitation of the aquifer, a more sustainable water management is required. The analysis of the local water resources system suggests that Managed Aquifer Recharge (MAR) would help to restore groundwater resources to strengthen water supply of Dhaka City, e.g., by using collected urban monsoon runoff and excess surface water from rivers. To assess possible effects of surface water or rainwater injection on groundwater quality, a comprehensive hydrogeochemical survey of the Dupitila aquifer is required. This paper presents hydrogeochemical data to document the current status of groundwater quality and to evaluate potential groundwater pollution by mobilization of hazardous chemicals as a result of changes in the hydrochemical equilibria. We performed a comprehensive review of available secondary data sources and will present new results from hydrochemical and Sr isotope investigations of water samples that were conducted within this study. Currently, groundwater quality in the upper Dupitila aquifer is characterized by variations in the electrical conductivity in the range of 200 to 1100 μS/cm, which may indicate some anthropogenic contamination by leakage from waste disposal including the sewage network and from surface water infiltration into the groundwater aquifer. Dissolved oxygen concentrations range from 1.0 to 4.9 mg/L (average 2.5 mg/L) in the upper Dupitila aquifer, while the lower Dupilita aquifer shows dissolved oxygen concentrations in the range 0 to 0.7 mg/L. Concentrations of major ions show some variation primarily due to a sedimentologically/mineralogically heterogeneous aquifer composition (sand, gravel, clay horizons), but may also be affected by anthropogenic processes. The groundwater composition is predominated by Ca-Mg-HCO3 and saturation values

  8. Planning an aquifer storage and recovery scheme in the Sherwood Sandstone aquifer

    OpenAIRE

    Pindoria-Nandha, Mital

    2016-01-01

    Aquifer Storage and Recovery (ASR) involves the injection of water into an aquifer for subsequent recovery from the same well. Whilst ASR provides a competitive alternative to reservoir storage, a lack of precedence of successful schemes and uncertainties with respect to regulatory requirements, and abstracted water quality and quantity have limited its implementation in the UK. The ambition of this research is to improve understanding of these impediments with particular refer...

  9. Naturally occurring contaminants in the Piedmont and Blue Ridge crystalline-rock aquifers and Piedmont Early Mesozoic basin siliciclastic-rock aquifers, eastern United States, 1994–2008

    Science.gov (United States)

    Chapman, Melinda J.; Cravotta, Charles A.; Szabo, Zoltan; Lindsay, Bruce D.

    2013-01-01

    Groundwater quality and aquifer lithologies in the Piedmont and Blue Ridge Physiographic Provinces in the eastern United States vary widely as a result of complex geologic history. Bedrock composition (mineralogy) and geochemical conditions in the aquifer directly affect the occurrence (presence in rock and groundwater) and distribution (concentration and mobility) of potential naturally occurring contaminants, such as arsenic and radionuclides, in drinking water. To evaluate potential relations between aquifer lithology and the spatial distribution of naturally occurring contaminants, the crystalline-rock aquifers of the Piedmont and Blue Ridge Physiographic Provinces and the siliciclastic-rock aquifers of the Early Mesozoic basin of the Piedmont Physiographic Province were divided into 14 lithologic groups, each having from 1 to 16 lithochemical subgroups, based on primary rock type, mineralogy, and weathering potential. Groundwater-quality data collected by the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program from 1994 through 2008 from 346 wells and springs in various hydrogeologic and land-use settings from Georgia through New Jersey were compiled and analyzed for this study. Analyses for most constituents were for filtered samples, and, thus, the compiled data consist largely of dissolved concentrations. Concentrations were compared to criteria for protection of human health, such as U.S. Environmental Protection Agency (USEPA) drinking water maximum contaminant levels and secondary maximum contaminant levels or health-based screening levels developed by the USGS NAWQA Program in cooperation with the USEPA, the New Jersey Department of Environmental Protection, and Oregon Health & Science University. Correlations among constituent concentrations, pH, and oxidation-reduction (redox) conditions were used to infer geochemical controls on constituent mobility within the aquifers. Of the 23 trace-element constituents evaluated

  10. Hydrochemistry and energy storage in aquifers

    NARCIS (Netherlands)

    Andersson, O.; Appelo, C.A.J.; Brons, H.J.; Dufour, F.C.; Griffioen, J.; Jenne, E.A.; Lyklema, J.W.; Mourik, G.J. van; Snijders, A.L.; Willemsen, A.; Zehnder, A.J.B.

    1990-01-01

    This volume of the series Proceedings and Information of the TNO Committee on Hydrological Research (CHO-TNO) contains the contributions as presented on the 48th technical meeting of the CHO-TNO, "Hydrochemistry and energy storage in aquifers". During this symposium recent results have been presente

  11. Transport of nonlinearly biodegradable contaminants in aquifers

    NARCIS (Netherlands)

    Keijzer, H.

    2001-01-01

    This thesis deals with the transport behavior of nonlinearly biodegradable contaminants in aquifers. Such transport occurs during in situ bioremediation which is based on the injection of an electron acceptor or electron donor. The main interests in this thesis are the mutual influences of underlyin

  12. Biogeochemical aspects of aquifer thermal energy storage.

    NARCIS (Netherlands)

    Brons, H.J.

    1992-01-01

    During the process of aquifer thermal energy storage the in situ temperature of the groundwater- sediment system may fluctuate significantly. As a result the groundwater characteristics can be considerably affected by a variety of chemical, biogeochemical and microbiological reactions. The inter

  13. Identifying turbulent flow in carbonate aquifers

    Science.gov (United States)

    Worthington, Stephen R. H.; Soley, Robert W. N.

    2017-09-01

    Turbulent flow has a different hydraulic response compared to laminar flow and so it is important to be able to identify its occurrence in an aquifer, and to predict where it is likely to be found. Turbulent flow is associated with large apertures and rapid velocities, and these occur most frequently in carbonate aquifers. Methods for identifying turbulent flow include correlating spring discharge with head variation, calculating Reynolds numbers from spring discharge and tracer velocity, and plotting the spatial variation of head differences between high flow and low flow. The probability of turbulent flow increases as a function of permeability and of spring discharge, and the probability increases in a downgradient direction in an aquifer. Spring discharge is a key parameter for evaluating the presence of turbulent flow, which is likely to occur where a spring with a discharge > 1 L/s is fed by a single channel. Turbulent flow appears to be a major contributing factor to the occurrence of groundwater flooding in carbonate aquifers.

  14. Hydrochemistry and energy storage in aquifers

    NARCIS (Netherlands)

    Andersson, O.; Appelo, C.A.J.; Brons, H.J.; Dufour, F.C.; Griffioen, J.; Jenne, E.A.; Lyklema, J.W.; Mourik, G.J. van; Snijders, A.L.; Willemsen, A.; Zehnder, A.J.B.

    1990-01-01

    This volume of the series Proceedings and Information of the TNO Committee on Hydrological Research (CHO-TNO) contains the contributions as presented on the 48th technical meeting of the CHO-TNO, "Hydrochemistry and energy storage in aquifers". During this symposium recent results have been

  15. Denitrification in a Sand and Gravel Aquifer: An Overview of a Long-Term Study

    Science.gov (United States)

    Smith, R. L.

    2002-12-01

    Denitrification can be a key process affecting the concentration and transport of nitrate in the subsurface. As a dissimilatory process, it has the potential to consume significant amounts of nitrate, once oxygen has been depleted, while serving as the predominant terminal electron-accepting reaction for the microbial food chain. Although denitrification has been extensively studied in soils and some surface water systems, relatively little is known about the process in the saturated subsurface. Consequently, a long-term study was established to examine the occurrence of denitrification in a sewage-contaminated, sand and gravel aquifer on Cape Cod, Massachusetts. This study included a characterization of the effect of the process on spatial and temporal distribution of inorganic nitrogen species along aquifer flow paths, the effect on nitrogen stable isotope distributions, and the overall effect on the process of dispersion and consumption of dissolved oxygen and dissolved organic carbon. A variety of laboratory and field studies have been conducted to quantify the overall rate of denitrification relative to subsurface flow, factors that control the process in the Cape Cod aquifer, and the steady-state dynamics of electron flow through the individual steps of the denitrification pathway. Under some conditions, the pathway was found to be unbalanced in the aquifer, causing accumulation of nitrogen oxide intermediates (nitrite, nitrous oxide, and nitric oxide) in the groundwater. Another aspect of this study was utilization of denitrification as a tool to remediate subsurface nitrate contamination. This included in situ enhancement tests using formate as an added electron donor and a laboratory project testing specific groups of denitrifiers isolated from the aquifer. Overall this long-term study has demonstrated that small-scale heterogeneity is a major factor that dictates and controls denitrification in an aquifer at any given locale, even systems viewed as

  16. Review of the general geology and solid-phase geochemical studies in the vicinity of the Central Oklahoma aquifer

    Science.gov (United States)

    Mosier, Elwin L.; Bullock, John H.

    1988-01-01

    The Central Oklahoma aquifer is the principal source of ground water for municipal, industrial, and rural use in central Oklahoma. Ground water in the aquifer is contained in consolidated sedimentary rocks consisting of the Admire, Council Grove, and Chase Groups, Wellington Formation, and Garber Sandstone and in the unconsolidated Quaternary alluvium and terrace deposits that occur along the major stream systems in the study area. The Garber Sandstone and the Wellington Formation comprise the main flow system and, as such, the aquifer is often referred to as the 'Garber-Wellington aquifer.' The consolidated sedimentary rocks consist of interbedded lenticular sandstone, shale, and siltstone beds deposited in similar deltaic environments in early Permian time. Arsenic, chromium, and selenium are found in the ground water of the Central Oklahoma aquifer in concentrations that, in places, exceed the primary drinking-water standards of the Environmental Protection Agency. Gross-alpha concentrations also exceed the primary standards in some wells, and uranium concentrations are uncommonly high in places. As a prerequisite to a surface and subsurface solid-phase geochemical study, this report summarizes the general geology of the Central Oklahoma study area. Summaries of results from certain previously reported solid-phase geochemical studies that relate to the vicinity of the Central Oklahoma aquifer are also given; including a summary of the analytical results and distribution plots for arsenic, selenium, chromium, thorium, uranium, copper, and barium from the U.S. Department of Energy's National Uranium Resource Evaluation (NURE) Program.

  17. A potential groundwater aquifer for palaeoclimate reconstruction: Turonian aquifer, Tadla basin, Morocco

    Science.gov (United States)

    Saadi, Radouan; Túri, Marianna; Palcsu, László; Marah, Hamid; Hakam, Oum Keltoum; Rinyu, László; Molnár, Mihály; Futó, István

    2017-08-01

    We undertook an environmental isotope investigation of groundwater from the Turonian Aquifer of Tadla Basin in Morocco in order to confirm that this aquifer could be a potential site for palaeoclimate reconstruction. The collected groundwater samples were examined for stable oxygen, hydrogen and carbon isotope ratio, as well as noble gases (He, Ne, Ar, Kr, Xe), 14C and 3H concentration. The measured stable oxygen and hydrogen isotope values show that the Turonian aquifer has two recharge areas, one with a heavier isotopic signature from the unconfined aquifer in the northern region (the area of Boujad), while the other is characterised by lighter isotopic composition in the north-eastern to the south-western part of the basin (to the North from Kasba Tadla). The calculated noble-gas solubility temperatures of the confined part of the aquifer are 2 °C higher than the recent mean annual air temperature (19 °C). Radiocarbon ages obtained from running different versions of Ingerson-Pearson models indicated that the recharge of this water occurred during the Holocene. We conclude that the Turonian aquifer might be a potential place for Late-Pleistocene palaeoclimate reconstruction if the research area were extended in the direct of flow path towards the western part of the basin and towards the foothills of the Phosphates Plateau.

  18. Digital Map Of Base of Aquifer for High Plains Aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital base of aquifer elevation contours for the High Plains aquifer in the central United States. The High Plains aquifer extends from...

  19. Digital map of aquifer boundary for the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set consists of aquifer boundaries for the High Plains aquifer in the central United States. The High Plains aquifer extends from south of 32...

  20. Hydrogeology - AQUIFER_SYSTEMS_BEDROCK_IDNR_IN: Bedrock Aquifer Systems of Indiana (Indiana Department of Natural Resources, 1:500,000, Polygon Shapefile)

    Data.gov (United States)

    NSGIC State | GIS Inventory — AQUIFER_SYSTEMS_BEDROCK_IDNR_IN is a polygon shapefile that shows bedrock aquifer systems of the State of Indiana. The source scale of the map depicting the aquifers...

  1. Hydrogeology - AQUIFER_SYSTEMS_BEDROCK_IDNR_IN: Bedrock Aquifer Systems of Indiana (Indiana Department of Natural Resources, 1:500,000, Polygon Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — AQUIFER_SYSTEMS_BEDROCK_IDNR_IN is a polygon shapefile that shows bedrock aquifer systems of the State of Indiana. The source scale of the map depicting the aquifers...

  2. Evaluation of long-term water-level declines in basalt aquifers near Mosier, Oregon

    Science.gov (United States)

    Burns, Erick R.; Morgan, David S.; Lee, Karl K.; Haynes, Jonathan V.; Conlon, Terrence D.

    2012-01-01

    The Mosier area lies along the Columbia River in northwestern Wasco County between the cities of Hood River and The Dalles, Oregon. Major water uses in the area are irrigation, municipal supply for the city of Mosier, and domestic supply for rural residents. The primary source of water is groundwater from the Columbia River Basalt Group (CRBG) aquifers that underlie the area. Concerns regarding this supply of water arose in the mid-1970s, when groundwater levels in the orchard tract area began to steadily decline. In the 1980s, the Oregon Water Resources Department (OWRD) conducted a study of the aquifer system, which resulted in delineation of an administrative area where parts of the Pomona and Priest Rapids aquifers were withdrawn from further appropriations for any use other than domestic supply. Despite this action, water levels continued to drop at approximately the same, nearly constant annual rate of about 4 feet per year, resulting in a current total decline of between 150 and 200 feet in many wells with continued downward trends. In 2005, the Mosier Watershed Council and the Wasco Soil and Water Conservation District began a cooperative investigation of the groundwater system with the U.S. Geological Survey. The objectives of the study were to advance the scientific understanding of the hydrology of the basin, to assess the sustainability of the water supply, to evaluate the causes of persistent groundwater-level declines, and to evaluate potential management strategies. An additional U.S. Geological Survey objective was to advance the understanding of CRBG aquifers, which are the primary source of water across a large part of Oregon, Washington, and Idaho. In many areas, significant groundwater level declines have resulted as these aquifers were heavily developed for agricultural, municipal, and domestic water supplies. Three major factors were identified as possible contributors to the water-level declines in the study area: (1) pumping at rates that

  3. Geodatabase compilation of hydrogeologic, remote sensing, and water-budget-component data for the High Plains aquifer, 2011

    Science.gov (United States)

    Houston, Natalie A.; Gonzales-Bradford, Sophia L.; Flynn, Amanda T.; Qi, Sharon L.; Peterson, Steven M.; Stanton, Jennifer S.; Ryter, Derek W.; Sohl, Terry L.; Senay, Gabriel B.

    2013-01-01

    The High Plains aquifer underlies almost 112 million acres in the central United States. It is one of the largest aquifers in the Nation in terms of annual groundwater withdrawals and provides drinking water for 2.3 million people. The High Plains aquifer has gained national and international attention as a highly stressed groundwater supply primarily because it has been appreciably depleted in some areas. The U.S. Geological Survey has an active program to monitor the changes in groundwater levels for the High Plains aquifer and has documented substantial water-level changes since predevelopment: the High Plains Groundwater Availability Study is part of a series of regional groundwater availability studies conducted to evaluate the availability and sustainability of major aquifers across the Nation. The goals of the regional groundwater studies are to quantify current groundwater resources in an aquifer system, evaluate how these resources have changed over time, and provide tools to better understand a systems response to future demands and environmental stresses. The purpose of this report is to present selected data developed and synthesized for the High Plains aquifer as part of the High Plains Groundwater Availability Study. The High Plains Groundwater Availability Study includes the development of a water-budget-component analysis for the High Plains completed in 2011 and development of a groundwater-flow model for the northern High Plains aquifer. Both of these tasks require large amounts of data about the High Plains aquifer. Data pertaining to the High Plains aquifer were collected, synthesized, and then organized into digital data containers called geodatabases. There are 8 geodatabases, 1 file geodatabase and 7 personal geodatabases, that have been grouped in three categories: hydrogeologic data, remote sensing data, and water-budget-component data. The hydrogeologic data pertaining to the northern High Plains aquifer is included in three separate

  4. Arsenic release during managed aquifer recharge (MAR)

    Science.gov (United States)

    Pichler, T.; Lazareva, O.; Druschel, G.

    2013-12-01

    The mobilization and addition of geogenic trace metals to groundwater is typically caused by anthropogenic perturbations of the physicochemical conditions in the aquifer. This can add dangerously high levels of toxins to groundwater, thus compromising its use as a source of drinking water. In several regions world-wide, aquifer storage and recovery (ASR), a form of managed aquifer recharge (MAR), faces the problem of arsenic release due to the injection of oxygenated storage water. To better understand this process we coupled geochemical reactive transport modeling to bench-scale leaching experiments to investigate and verify the mobilization of geogenic arsenic (As) under a range of redox conditions from an arsenic-rich pyrite bearing limestone aquifer in Central Florida. Modeling and experimental observations showed similar results and confirmed the following: (1) native groundwater and aquifer matrix, including pyrite, were in chemical equilibrium, thus preventing the release of As due to pyrite dissolution under ambient conditions; (2) mixing of oxygen-rich surface water with oxygen-depleted native groundwater changed the redox conditions and promoted the dissolution of pyrite, and (3) the behavior of As along a flow path was controlled by a complex series of interconnected reactions. This included the oxidative dissolution of pyrite and simultaneous sorption of As onto neo-formed hydrous ferric oxides (HFO), followed by the reductive dissolution of HFO and secondary release of adsorbed As under reducing conditions. Arsenic contamination of drinking water in these systems is thus controlled by the re-equilibration of the system to more reducing conditions rather than a purely oxidative process.

  5. Stable isotope hydrology in fractured and detritic aquifers at both sides of the South Atlantic Ocean: Mar del Plata (Argentina) and the Rawsonville and Sandspruit river catchment areas (South Africa)

    Science.gov (United States)

    Glok Galli, Melisa; Damons, Matthew E.; Siwawa, Sitembiso; Bocanegra, Emilia M.; Nel, Jacobus M.; Mazvimavi, Dominic; Martínez, Daniel E.

    2017-01-01

    The aim of this work is to characterize the isotope composition of water (2H and 18O) in order to establish the relationship between fractured and detritic aquifers in similar hydrological environments located at both sides of the Atlantic Ocean. The Mar del Plata zone, placed in the Argentine Buenos Aires province in South America, and the Rawsonville and Sandspruit river catchment areas, situated in the Western Cape province in South Africa were compared. Rainwater and groundwater samples from fractured and detritic aquifers were analyzed through laser spectroscopy. In both Argentina and South African study sites, stable isotopes data demonstrate an aquifers recharge source from rainfall. For the Mar del Plata region, two different groups of detritic aquifer's samples with distinct recharge processes can be identified due to the close relationship existing between the present hydrogeological environments, the aquifer's grain size sediments and the isotopes contents: one representing rapid infiltration in aquifer sediments of the creeks' palaeobeds and hills zones (sandy or silt sandy sediments) and the other with slow infiltration of evaporated water in plain zones with an aquitard behavior. In the last group, the evaporation process occurs previous infiltration or in the aquifer's non-saturated zone, because of the existence of very low topographic gradients and fine-grained sediments. The evaporation phenomenon is not evident in the Sandspruit river catchment site's detritic aquifer, because its sandy composition allows a faster infiltration rate than in the loess that compounds the Pampeano aquifer in the interfluves zones of the Argentinian study area.

  6. Assessment of natural recharges of the Plio-Plistocene shallow aquifer system in Al Uja area /Lower Jordan Valley / Occupied Palestinian Territories

    Science.gov (United States)

    Manasra, Kayan; Marei, Amer; Sbiah, Mohamed; Uter, Hussam; Abu Thaher, Ayman

    2013-04-01

    Al Uja area locates in the Lower Jordan Valley/West Bank at 250 m below sea level. The availability of ground water, fertile soil, and warm climate during winter months make it remarkable for its agricultural activities where 600 hectares are under irrigation. Al Uja karstic spring that drain water from the Mountain carbonate aquifer system with a discharge rate between 0.5 and 8 MCM/a , and nine groundwater boreholes that tape water from the shallow Plio-Plistocene aquifer system, with an annual abstraction of 3.5 MCM are the water sources. The south-north fault system of the Jordan Rift Valley separates the two aquifer system. The shallow aquifer system locates to the east of the fault, where the Mountain aquifer system locates to the west. The Mountain aquifer consists of high fractured and karstified limestone and dolomite of Upper Cretaceous age, and the shallow aquifer system consists of gravel, sand, silt, and clay layers of the Dead Sea group. Groundwater recharge of the Mountain aquifer system takes place in the highland area in the West with an annual precipitation of about 550 mm. Formations of the shallow aquifer system crop out in the Jordan Valley where rainfall does not exceed 250 mm/a . Due to the high evaporation rate, direct recharge is neglected. Only small portion of flooding water about 0.4MCM/a infiltrate through wadi Al Uja drainage system in to the Alluvial deposits to the shallow aquifer system. In the other hand, and since more than 40 years, the nine groundwater boreholes are taping about 3 MCM/a, water table decline of about 5 m. Currently, water table locates between -290 m in the west and decrease to - 311 m in the east. Groundwater flows from the Mountain aquifer in the west to the Shallow aquifer in the east through the major fault system. The permeability of the Mountain carbonate layers is 2.49E-1 m/min and decrease to 1.6 E-2 m/min in the layers of the Shallow aquifer system, this decrease of Kf-value east wards cause a semi

  7. Monitoring Aquifer Depletion from Space: Case Studies from the Saharan and Arabian Aquifers

    Science.gov (United States)

    Ahmed, M.; Sultan, M.; Wahr, J. M.; Yan, E.

    2013-12-01

    Access to potable fresh water resources is a human right and a basic requirement for economic development in any society. In arid and semi-arid areas, the characterization and understanding of the geologic and hydrologic settings of, and the controlling factors affecting, these resources is gaining increasing importance due to the challenges posed by increasing population. In these areas, there is immense natural fossil fresh water resources stored in large extensive aquifers, the transboundary aquifers. Yet, natural phenomena (e.g., rainfall patterns and climate change) together with human-related factors (e.g., population growth, unsustainable over-exploitation, and pollution) are threatening the sustainability of these resources. In this study, we are developing and applying an integrated cost-effective approach to investigate the nature (i.e., natural and anthropogenic) and the controlling factors affecting the hydrologic settings of the Saharan (i.e., Nubian Sandstone Aquifer System [NSAS], Northwest Sahara Aquifer System [NWSA]) and Arabian (i.e., Arabian Peninsula Aquifer System [APAS]) aquifer systems. Analysis of the Gravity Recovery and Climate Experiment (GRACE)-derived Terrestrial Water Storage (TWS) inter-annual trends over the NSAS and the APAS revealed two areas of significant TWS depletions; the first correlated with the Dakhla Aquifer System (DAS) in the NSAS and second with the Saq Aquifer System (SAS) in the APAS. Annual depletion rates were estimated at 1.3 × 0.66 × 109 m3/yr and 6.95 × 0.68 × 109 m3/yr for DAS and SAS, respectively. Findings include (1) excessive groundwater extraction, not climatic changes, is responsible for the observed TWS depletions ;(2) the DAS could be consumed in 350 years if extraction rates continue to double every 50 years and the APAS available reserves could be consumed within 60-140 years at present extraction (7.08 × 109 m3/yr) and depletion rates; and (3) observed depletions over DAS and SAS and their

  8. Spatial analysis of climatic cycles of a detrital aquifer by mean of Indicator Kriging

    Science.gov (United States)

    Luque-Espinar, Juan Antonio; Pardo-Igúzquiza, Eulogio; Pulido-Velazquez, David; Fernández-Chacón, Francisca; Jiménez-Sánchez, Jorge; Chica-Olmo, Mario

    2016-04-01

    In a previous work, spectral analysis was carried out to investigate the climate cycles in a detrital aquifer located in southern Spain. The Vega de Granada aquifer is located in an alluvial plain surrounded by mountains. The aquifer has a superposition of Quaternary sedimentary materials showing a broad range of permeabilities. This aquifer is the receptor of a drainage basin of 2900 km2 and has a surface of around 200 km2. Its alluvial sediments attain a thickness of 250 m in the middle. The sediment sizes are mainly gravel, sands, silts and clay, with frequent spatial changes. The transmissivity of the range from 40000 m2/day to 100 m2/day and the effective porosity ranging between 1% and 10%. The main inputs into the aquifer come from the infiltration of surface runoff and the infiltration of rainfall water. More than 50 piezometric data series were studied with monthly temporal unit. The studied period has a span of more than 30 years. The main climatic cycles are annual, NAO, ENSO and semiannual. For this study, confidence levels of <90%, 90%, 95%, and 99% were established. The spatial distribution in the aquifer of climate cycles and their confidence levels were studied by mean Indicator Kriging. This methodology is based on geostatistical non-parametric methods. For this purpose, the confidence levels were codified in indicator variables. Overall, eleven experimental variograms were calculated and it fitted to a spherical model. In this sense, the spatial behavior of the climate cycles is quite similar in all cases. The estimation results are presented as binary maps that show areas where every cycle appears with a maximum spatial probability. Basically, the interpretation of these maps indicates a close connection to main recharge areas of the aquifer. On the other hand, the changes in permeability in the aquifer are considerable, which may explain in some cases the spatial variations in the spectra calculated. Acknowledgments: This research has been

  9. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas.

    Science.gov (United States)

    Musgrove, M; Opsahl, S P; Mahler, B J; Herrington, C; Sample, T L; Banta, J R

    2016-10-15

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO3(-)) loading to surface and groundwater. We investigate variability and sources of NO3(-) in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008-12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO3(-) stable isotopes (δ(15)N and δ(18)O). These data were augmented by historical data collected from 1937 to 2007. NO3(-) concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO3(-) concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO3(-) concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO3(-). These results highlight the vulnerability of karst aquifers to NO3(-) contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008-10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO3(-) than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates that subaqueous nitrification of organic N in the aquifer, as opposed to in soils, might be a previously unrecognized

  10. Selecting Aquifer Wells for Planned Gyroscopic Logging

    Energy Technology Data Exchange (ETDEWEB)

    Rohe, Michael James; Studley, Gregory Wayne

    2002-04-01

    Understanding the configuration of the eastern Snake River Plain aquifer's water table is made difficult, in part, due to borehole deviation in aquifer wells. A borehole has deviation if it is not vertical or straight. Deviation impairs the analysis of water table elevation measurements because it results in measurements that are greater than the true distance from the top of the well to the water table. Conceptual models of the water table configuration are important to environmental management decision-making at the INEEL; these models are based on measurements of depth to the water table taken from aquifer wells at or near the INEEL. When accurate data on the amount of deviation in any given borehole is acquired, then measurements of depth-to-water can be adjusted to reflect the true depth so more accurate conceptual models can be developed. Collection of additional borehole deviation data with gyroscopic logging is planned for selected wells to further our confidence in the quality of water level measurements. Selection of wells for the planned logging is based on qualitative and quantitative screening criteria. An existing data set from magnetic deviation logs was useful in establishing these criteria however, are considered less accurate than gyroscopic deviation logs under certain conditions. Population distributions for 128 aquifer wells with magnetic deviation data were used to establish three quantitative screening thresholds. Qualitative criteria consisted of administrative controls, accessibility issues, and drilling methods. Qualitative criteria eliminated all but 116 of the 337 aquifer wells, in the vicinity of the INEEL, that were initially examined in this screening effort. Of these, 72 have associated magnetic deviation data; 44 do not. Twenty-five (25) of the 72 wells with magnetic deviation data have deviation greater than one of the three quantitative screening thresholds. These 25 are recommended for the planned gyroscopic borehole deviation

  11. The High Plains Aquifer, USA: Groundwater development and sustainability

    Science.gov (United States)

    Dennehy, K.F.; Litke, D.W.; McMahon, P.B.

    2002-01-01

    The High Plains Aquifer, located in the United States, is one of the largest freshwater aquifers in the world and is threatened by continued decline in water levels and deteriorating water quality. Understanding the physical and cultural features of this area is essential to assessing the factors that affect this groundwater resource. About 27% of the irrigated land in the United States overlies this aquifer, which yields about 30% of the nation's groundwater used for irrigation of crops including wheat, corn, sorghum, cotton and alfalfa. In addition, the aquifer provides drinking water to 82% of the 2.3 million people who live within the aquifer boundary. The High Plains Aquifer has been significantly impacted by human activities. Groundwater withdrawals from the aquifer exceed recharge in many areas, resulting in substantial declines in groundwater level. Residents once believed that the aquifer was an unlimited resource of high-quality water, but they now face the prospect that much of the water may be gone in the near future. Also, agricultural chemicals are affecting the groundwater quality. Increasing concentrations of nitrate and salinity can first impair the use of the water for public supply and then affect its suitability for irrigation. A variety of technical and institutional measures are currently being planned and implemented across the aquifer area in an attempt to sustain this groundwater resource for future generations. However, because groundwater withdrawals remain high and water quality impairments are becoming more commonplace, the sustainability of the High Plains Aquifer is uncertain.

  12. Diversity of arsenite oxidizing bacterial communities in arsenic-rich deltaic aquifers in West Bengal, India

    Directory of Open Access Journals (Sweden)

    Devanita eGhosh

    2014-11-01

    Full Text Available High arsenic (As concentration in groundwater has affected human health, particularly in South-East Asia putting millions of people at risk. Biogeochemical cycling of As carried out by different bacterial groups are suggested to control the As fluxes in aquifers. A functional diversity approach in link with As precipitation was adopted to study bacterial community structures and their variation within the As contaminated Bengal Delta Plain (BDP aquifers of India. Groundwater samples collected from two shallow aquifers in Karimpur II (West Bengal, India, during years 2010 and 2011, were investigated to trace the effects of inter-annual variability in precipitation on community structure and diversity of bacterial assemblages. The study focused on amplification, clone library generation and sequencing of the arsenite oxidase large sub-unit gene aioA and 16S rRNA marker, with respect to changes in elemental concentrations. New set of primers were designed to amplify the aioA gene as a phylogenetic marker to study taxonomically diverse arsenite oxidizing bacterial groups in these aquifers. Overall narrow distribution of bacterial communities based on aioA and 16S rRNA sequences observed was due to poor nutrient status and anoxic conditions in these As contaminated aquifers. Proteobacteria was the dominant phylum detected, within which Acidovorax, Hydrogenophaga, Albidiferax, Bosea and Polymorphum were the major arsenite oxidizing bacterial genera. The structure of bacterial assemblages including those of arsenite oxidizing bacteria were affected by an increase in major elemental concentrations (e.g., As, iron, sulfur, and silica within two sampling sessions, which was supported by PCA analysis. One of the significant findings of this study is detection of novel lineages of 16S rRNA-like bacterial sequences indicating presence of indigenous bacterial communities across both wells of BDP that can play important role in biogeochemical cycling of

  13. Opportunities to enhance management of karstic aquifers

    Science.gov (United States)

    Parizek, Richard R.

    2007-01-01

    Methods exist to obtain “new sources of water.” Examples include: (1) capturing and enhancing stormwater recharge and retention within diffuse-flow portions of karst and other aquifers; (2) recycling and reuse of waste water; (3) reducing evapotranspiration and rejected recharge; and (4) ameliorating atmospheric acid deposition through use of alkaline groundwater. These little used management methods have immense potential to sustain future water demands. Full utilization of “new” and traditional water resources requires an understanding of the hydrogeologic framework of karstic aquifers. Reliable conceptual, numerical flow and transport models are needed to help evaluate, select, and design viable water management options. Three such simulation examples are provided together with a discussion of Penn State’s Wastewater reuse project where recharge approaches 3.785 × 109l/year

  14. Atrazine removal in Danish anaerobic aquifers

    DEFF Research Database (Denmark)

    Pedersen, Philip Grinder; Arildskov, N.P.; Albrechtsen, Hans-Jørgen

    2002-01-01

    The pesticide atrazine (6-chloro-N-2-ethyl-N-4-isopropyl-1,3,5-triazine -2,4-diamine) was removed from the water phase in anaerobic laboratory batch incubations with sediment and groundwater from a number of Danish anaerobic aquifers, but not in incubations from aerobic aquifers. The removal...... process was abiotic since atrazine was also removed from microbially inhibited autoclaved and chloroform amended controls, although in controls amended with mercury, atrazine removal was slowed down. (ring-U-C-14)- atrazine amended samples showed no mineralization to (CO2)-C-14 or transformation...... to soluble degradation products, indicating that a slow sorption process was responsible for the atrazine removal. Approximately 20% of the applied C-14-atrazine was present in a non-extractable residual sediment bound fraction, indicating the slow sorption process to be in part irreversible...

  15. Environmental effects of aquifer overexploitation: a case study in the highlands of Mexico.

    Science.gov (United States)

    Esteller, Maria Vicenta; Diaz-Delgado, Carlos

    2002-02-01

    There are several environmental processes occurring under aquifer overexploitation conditions. These processes include groundwater table decline, subsidence, attenuation and drying of springs, decrease of river flow, and increased pollution vulnerability, among others processes. Some of these effects have been observed on the Upper Basin of the Lerma River. The Lerma River begins in the SE of the Valley of Toluca at 2,600 m asl, in the wetland known as Lagoons of Almoloya del Río. This wetland is made up of a group of lagoons, which are an important aquatic system from an environmental point of view. The water inflow of this wetland is a discharge of springs, which occur between the fractured volcanic material of the mountain range and granular volcanic-continental deposits of the Valley of Toluca aquifer. The intensive exploitation of the Valley of Toluca aquifer to supply urban and industrial water to Mexico City and Toluca began in 1950 and is responsible for a steady decline of piezometric levels of 1-3.5 m/yr. Other effects of this exploitation--the drying of the wetland, the decrease of river flow and the land subsidence--caused serious ecological and social impacts. The authorities declared this aquifer as overexploited in order to reduce the exploitation and preserve the availability of water resources in this important region.

  16. Policy Preferences about Managed Aquifer Recharge for Securing Sustainable Water Supply to Chennai City, India

    Directory of Open Access Journals (Sweden)

    Norbert Brunner

    2014-12-01

    Full Text Available The objective of this study is to bring out the policy changes with respect to managed aquifer recharge (focusing on infiltration ponds, which in the view of relevant stakeholders may ease the problem of groundwater depletion in the context of Chennai City; Tamil Nadu; India. Groundwater is needed for the drinking water security of Chennai and overexploitation has resulted in depletion and seawater intrusion. Current policies at the municipal; state and national level all support recharge of groundwater and rainwater harvesting to counter groundwater depletion. However, despite such favorable policies, the legal framework and the administrative praxis do not support systematic approaches towards managed aquifer recharge in the periphery of Chennai. The present study confirms this, considering the mandates of governmental key-actors and a survey of the preferences and motives of stakeholder representatives. There are about 25 stakeholder groups with interests in groundwater issues, but they lack a common vision. For example, conflicting interest of stakeholders may hinder implementation of certain types of managed aquifer recharge methods. To overcome this problem, most stakeholders support the idea to establish an authority in the state for licensing groundwater extraction and overseeing managed aquifer recharge.

  17. Groundwater resource evaluation of urban Bulawayo aquifer

    CSIR Research Space (South Africa)

    Rusinga, F

    2005-01-01

    Full Text Available mafic and ultramafic sills and dykes. Because of its prevalent mafic character which tends to promote deep weathering, the rock formation supports an aquifer with fairly good water storage capacity and permeability. Hydrogeophysical investigations... the secondary porosity of the formation to chemical weathering in contrast to the proposition of Weaver et al. (1992) that the secondary porosity in the well-field was due to fracturing. The proposition of Weaver et al. (1992) lends itself to widely...

  18. Nitrate in aquifers beneath agricultural systems.

    Science.gov (United States)

    Burkart, M R; Stoner, J D

    2007-01-01

    Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWQA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and also shallow carbonate aquifers that provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The system of corn, soybean, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems because this system imports the largest amount of N-fertilizer per unit production area. Mean nitrate under dairy, poultry, horticulture, and cattle and grains systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as

  19. Groundwater sustainability assessment in coastal aquifers

    Indian Academy of Sciences (India)

    U A Lathashri; A Mahesha

    2016-08-01

    The present work investigates the response of shallow, coastal unconfined aquifers to anticipated overdraft conditions and climate change effect using numerical simulation. The groundwater flow model MODFLOW and variable density groundwater model SEAWAT are used for this investigation. The transmissivity and specific yield estimated from the existing database range from 10 to 810 m^2/day and 0.08% to 10.92% respectively. After successful calibration with Nash–Sutcliffe efficiency greater than 0.80, the values of horizontal hydraulic conductivity and specific yield of the unconfined aquifer were set in the range 1.85–61.90 m/day and 0.006–0.24 respectively. After validating the model, it is applied for forecasting the aquifer’s response to anticipated future scenarios of groundwater draft, recharge rate and sea level rise. The findings of the study illustrate that saltwater intrusion is intensified in the area adjoining the tidal rivers, rather than that due to the sea alone. Of all the scenarios simulated, the immense negative impact on groundwater quality emerges due to overdraft conditions and reduced recharge with the areal extent of seawater intrusion exceeding about 67% (TDS>1 kg/m^3). The study also arrivesat the conclusion that, regional sea level rise of 1 mm/year has no impact on the groundwater dynamics of the aquifer.

  20. Aquifer transmissivity of porous media from resistivity data

    Science.gov (United States)

    Niwas, Sri; Singhal, D. C.

    1985-11-01

    To optimize the information/cost ratio and avoid the indiscriminate and excessive use of drilling and pump testing to calculate aquifer transmissivity an analytical relationship between modified transverse resistance and aquifer transmissivity has been developed for estimating transmissivity from resistivity sounding data. The relation takes into consideration the variation in the quality of groundwater. The relation has been tested successfully for the glacial aquifers of Rhode Island, U.S.A. and alluvial aquifers of three different areas of Uttar Pradesh, India. The practical applicability of the relation lies in the fact that if hydraulic conductivity is known for any reference point of a porous homogeneous aquifer, one can get fairly good idea of the transmissivity of the aquifer at other locations within a basin, from surface geo-electrical measurements.

  1. Unconfined Aquifer Flow Theory - from Dupuit to present

    CERN Document Server

    Mishra, Phoolendra K

    2013-01-01

    Analytic and semi-analytic solution are often used by researchers and practicioners to estimate aquifer parameters from unconfined aquifer pumping tests. The non-linearities associated with unconfined (i.e., water table) aquifer tests makes their analysis more complex than confined tests. Although analytical solutions for unconfined flow began in the mid-1800s with Dupuit, Thiem was possibly the first to use them to estimate aquifer parameters from pumping tests in the early 1900s. In the 1950s, Boulton developed the first transient well test solution specialized to unconfined flow. By the 1970s Neuman had developed solutions considering both primary transient storage mechanisms (confined storage and delayed yield) without non-physical fitting parameters. In the last decade, research into developing unconfined aquifer test solutions has mostly focused on explicitly coupling the aquifer with the linearized vadose zone. Despite the many advanced solution methods available, there still exists a need for realism ...

  2. Numerical Simulation of Reactive Flow in Hot Aquifers

    Science.gov (United States)

    Smith, Leslie

    2004-02-01

    In recent years, there has been a significant expansion in our ability to model systems that involve the interaction of fluid flow, mass transport, heat transfer, and geochemical reaction in porous media. Such scenarios arise in studies of both fundamental science, such as the effects of thermohaline flow and heat transfer in rift basins, and in the solution of applied problems, such as the response of a geothermal reservoir to the re-injection of cool water. Numerical Simulation of Reactive Flow in Hot Aquifers presents the simulation tools that were developed by a team of researchers based in Germany. This group has a long history in analyzing geothermal systems, but the methods presented can be applied far beyond the study of geothermal reservoirs. The heart of the book is a description of the model SHEMAT. The executable code and a graphical user interface are included with the book.

  3. Numerical Study on Saltwater Instrusion in a Heterogeneous Stratified Aquifer

    OpenAIRE

    2000-01-01

    In a costal aquifer, saltwater intrusion is frequently observed due to an excess exploitation. There are many researches focused on the saltwater intrusion. However, there are few researches, which take into consideration the mixing processes in a stratified heterogeneous aquifer. In the present study, a laboratory experiment and numerical simulation are made in order to understand the phenomena in a stratified heterogeneous aquifer. The result of the numerical analysis agrees well with the m...

  4. Field Measurements and Modeling of the Southeast Greenland Firn Aquifer

    Science.gov (United States)

    Miller, O. L.; Solomon, D. K.; Miège, C.; Voss, C. I.; Koenig, L.; Forster, R. R.; Schmerr, N. C.; Montgomery, L. N.; Legchenko, A.; Ligtenberg, S.

    2016-12-01

    An extensive firn aquifer forms in southeast Greenland as surface meltwater percolates through the upper seasonal snow and firn layers to depth and saturates open pore spaces. The firn aquifer is found at depths from about 10 to 35 m below the snow surface in areas with high accumulation rates and high melt rates. The firn aquifer retains significant volume of meltwater and heat within the ice sheet. The first-ever hydrologic and geochemical measurements from several boreholes drilled into the aquifer have been made 50 km upstream of Helheim Glacier terminus in SE Greenland. This field data is used with a version of the SUTRA groundwater simulator that represents the freeze/thaw process to model the hydrologic and thermal conditions of the ice sheet, including aquifer water recharge, lateral flow, and discharge. Meltwater generation during the summer season is modeled using degree day methods, and meltwater recharge to the aquifer (10-70 cm/year) is calculated using water level fluctuations and volumetric flow measurements (3e-7 to 5e-6 m3/s). Aquifer hydrologic parameters, including hydraulic conductivity (2e-5 to 4e -4 m/s), storativity, and specific discharge (3e-7 to 5e-6 m/s), are estimated from aquifer pumping tests and tracer experiments. In situ measurements were obtained using a novel heated piezometer, which advances downward through the unsaturated and saturated zones of the aquifer by melting the surrounding firn. Innovative modeling approaches blending unsaturated and saturated groundwater flow modeling and ice thermodynamics indicate the importance of surface topography controls on fluid flow within the aquifer, and forecast the nature and volume of aquifer water discharge into crevasses at the edge of the ice sheet. This pioneering study is crucial to understanding the aquifer's influence on mass balance estimates of the ice sheet.

  5. Management of aquifer recharge in Lebanon by removing seawater intrusion from coastal aquifers.

    Science.gov (United States)

    Masciopinto, Costantino

    2013-11-30

    This study investigates the feasibility of management of aquifer recharge (MAR) in Lebanon by designing well barriers to remove seawater intrusion from the fractured carbonate aquifers. Groundwater flow and saltwater/freshwater 50% sharp interface have been modeled along the coastal area using the Ghyben-Herzberg theory. The groundwater flow simulations have been supported by field transmissivity estimations and depth measurements carried out on 44 wells during 2003. Results have shown the seawater intrusion in coastal aquifers at Jieh and Damour regions. Three well-injection barriers have been proposed. The water volumes for recharge and the barrier positions have been defined by means of groundwater flow simulations. MAR can provide a valuable contribution to colloid (even pathogen) removal from injectant water, although during water infiltration in subsoil the reduction of aquifer permeability causes clogging. A simple new model for estimating the soil-rock permeability reduction due to the well clogging has been presented. The MAR, including the soil aquifer treatment at Damour and Jieh regions, has been studied by considering aquifer transmissivity (and soil porosity) reduction caused by clogging. Furthermore, the appropriate mixing of the injectant water by using reclaimed water, groundwater and surface water can be simulated using the proposed models. The time required to achieve 5% of rock permeability reduction at the proposed well barriers ranged from 71 to 935 d, by changing water quality and flow rate for recharge. This study can assist regional governments with water management in areas affected by scarcity of freshwater by implementing appropriate well-barrier projects.

  6. Recharge and Aquifer Response: Manukan Island’s Aquifer, Sabah, Malaysia

    Directory of Open Access Journals (Sweden)

    Sarva Mangala Praveena

    2010-01-01

    Full Text Available Manukan Island is a small island located in North-West of Sabah, Malaysia was used as a case study area for numerical modeling of an aquifer response to recharge and pumping rates. The results in this study present the variations of recharge into the aquifer under the prediction simulations. The recharge rate increases the water level as indicated by hydraulic heads. This shows that it can alter groundwater of Manukan Island which has been suffering from an overexploration in its unconfined the aquifer. The increase in recharge rate (from 600 mm/year to 750 mm/year increases the water level indicated by hydraulic heads. A reduction in pumping rate (from 0.072 m3/day to 0.058 m3/day not only increases the amount of water levels in aquifer but also reduces the supply hence a deficit in supply. The increase in hydraulic heads depends on the percentage reduction of pumping and recharges rates. The well water has 1978.3 mg/L chloride with current pumping (0.072 m3/day and recharge rates (600 mm/year. However, with an increased of recharge rate and current pumping rate it has decreased about 1.13%. In addition, reduction in pumping rate made the chloride concentration decreased about 2.8%. In general, a reduction in pumping with an increase in recharge rate leads to a decreased in chloride concentrations within the vicinity of cone of depression. Next, to further develop the numerical model, the model should focus on climate change variables such as consequences of climate change are increase in air temperature, increase in sea surface temperature, and more extreme weather conditions. These parameters are considered critical parameters for climate change impact modeling in aquifers. The behavior of the aquifer and its sustainable pumping rate can be done by applying a computer modeling component.

  7. Slugtests in fractured aquifers - advantages and caveats

    Science.gov (United States)

    Sauter, Martin

    2017-04-01

    The hydraulic characterisation of fractured aquifers is a challenge due to the large contrast between conductive fractures and a relative low conductive rock matrix. Depending on the type of problem, spanning from water resources issues at catchment scale to contaminant transport at local, borehole scale, different methodological approaches are required. The employment of slugtests as a characterisation method has a major advantage above classical pumping tests since they provide information also for the lower end of the permeability spectrum and are less logistically demanding. However, the volume of investigation of slugtests is generally small and limited to the immediate borehole area. The application of slug tests to fractured systems was investigated by Barker and Black (1983); Dougherty and Babu (1984) and Karasaki et al. (1988). Barker and Black (1983) pointed out the non-uniqueness of type curves with re¬spect to determining reservoir parameters, apart from hydraulic conductivity and sto¬rage coefficients. The unknowns in¬clude fissure densities, apertures and the hy¬draulic parameters of the rock matrix. They found that the Cooper method syste¬matically overestimates aquifer transmis-sivities by a factor of up to three. This figure however applies to a fairly homogeneously fissured aquifer such as the English Chalk. Dougherty and Babu (1984) examined in detail the effects of partial penetration, dif¬ferent skin factors and mass exchange coef-ficients in a double porosity system. They did however not present any parameter estimation solu¬tion. Karasaki et al. (1988) developed type curves for heterogeneous aquifer systems and came to the conclusion that "slug tests suffer problems of non-uniqueness to a greater ex¬tent than other well tests". In this paper, this aspect of non-uniqueness is addressed in detail, based on slugtest data in a fractured and karstified aquifer from the Swabian Alb in the SW of Germany, explanations and models of

  8. Microbiological risks of recycling urban stormwater via aquifers.

    Science.gov (United States)

    Page, D; Gonzalez, D; Dillon, P

    2012-01-01

    With the release of the Australian Guidelines for Water Recycling: Managed Aquifer Recharge (MAR), aquifers are now being included as a treatment barrier when assessing risk of recycled water systems. A MAR research site recharging urban stormwater in a confined aquifer was used in conjunction with a Quantitative Microbial Risk Assessment to assess the microbial pathogen risk in the recovered water for different end uses. The assessment involved undertaking a detailed assessment of the treatment steps and exposure controls, including the aquifer, to achieve the microbial health-based targets.

  9. Characteristics of Southern California coastal aquifer systems

    Science.gov (United States)

    Edwards, B.D.; Hanson, R.T.; Reichard, E.G.; Johnson, T.A.

    2009-01-01

    Most groundwater produced within coastal Southern California occurs within three main types of siliciclastic basins: (1) deep (>600 m), elongate basins of the Transverse Ranges Physiographic Province, where basin axes and related fluvial systems strike parallel to tectonic structure, (2) deep (>6000 m), broad basins of the Los Angeles and Orange County coastal plains in the northern part of the Peninsular Ranges Physiographic Province, where fluvial systems cut across tectonic structure at high angles, and (3) shallow (75-350 m), relatively narrow fluvial valleys of the generally mountainous southern part of the Peninsular Ranges Physiographic Province in San Diego County. Groundwater pumped for agricultural, industrial, municipal, and private use from coastal aquifers within these basins increased with population growth since the mid-1850s. Despite a significant influx of imported water into the region in recent times, groundwater, although reduced as a component of total consumption, still constitutes a significant component of water supply. Historically, overdraft from the aquifers has caused land surface subsidence, flow between water basins with related migration of groundwater contaminants, as well as seawater intrusion into many shallow coastal aquifers. Although these effects have impacted water quality, most basins, particularly those with deeper aquifer systems, meet or exceed state and national primary and secondary drinking water standards. Municipalities, academicians, and local water and governmental agencies have studied the stratigraphy of these basins intensely since the early 1900s with the goals of understanding and better managing the important groundwater resource. Lack of a coordinated effort, due in part to jurisdictional issues, combined with the application of lithostratigraphic correlation techniques (based primarily on well cuttings coupled with limited borehole geophysics) have produced an often confusing, and occasionally conflicting

  10. Development Report on the Idaho National Laboratory Sitewide Three-Dimensional Aquifer Model

    Energy Technology Data Exchange (ETDEWEB)

    Thomas R. Wood; Catherine M. Helm-Clark; Hai Huang; Swen Magnuson; Travis McLing; Brennon Orr; Michael J. Rohe; Mitchell A. Plummer; Robert Podgorney; Erik Whitmore; Michael S. Roddy

    2007-09-01

    A sub-regional scale, three-dimensional flow model of the Snake River Plain Aquifer was developed to support remediation decisions for Waste Area Group 10, Operable Unit 10 08 at the Idaho National Laboratory (INL) Site. This model has been calibrated primarily to water levels and secondarily to groundwater velocities interpreted from stable isotope disequilibrium studies and the movement of anthropogenic contaminants in the aquifer from facilities at the INL. The three-dimensional flow model described in this report is one step in the process of constructing a fully three-dimensional groundwater flow and contaminant transport model as prescribed in the Idaho National Engineering and Environmental Laboratory Operable Unit 10-08 Sitewide Groundwater Model Work Plan. An updated three-dimensional hydrogeologic conceptual model is presented along with the geologic basis for the conceptual model. Sediment-dominated three-dimensional volumes were used to represent the geology and constrain groundwater flow as part of the conceptual model. Hydrological, geochemical, and geological data were summarized and evaluated to infer aquifer behavior. A primary observation from development and evaluation of the conceptual model was that relative to flow on a regional scale, the aquifer can be treated with steady-state conditions. Boundary conditions developed for the three-dimensional flow model are presented along with inverse simulations that estimate parameterization of hydraulic conductivity. Inverse simulations were performed using the pilot-point method to estimate permeability distributions. Thermal modeling at the regional aquifer scale and at the sub-regional scale using the inverted permeabilities is presented to corroborate the results of the flow model. The results from the flow model show good agreement with simulated and observed water levels almost always within 1 meter. Simulated velocities show generally good agreement with some discrepancies in an interpreted low

  11. Hydrogeology of the Cambrian-Ordovician aquifer system in the northern Midwest: B in Regional aquifer-system analysis

    Science.gov (United States)

    Young, H.L.; Siegel, D.I.

    1992-01-01

    The Cambrian-Ordovician aquifer system contains the most extensive and continuous aquifers in the northern Midwest of the United States. It is the source of water for many municipalities, industries, and rural water users. Since the beginning of ground-water development from the aquifer system in the late 1800's, hydraulic heads have declined hundreds of feet in the heavily pumped Chicago-Milwaukee area and somewhat less in other metropolitan areas. The U.S. Geological Survey has completed a regional assessment of this aquifer system within a 161,000-square-mile area encompassing northern Illinois, northwestern Indiana, Iowa, southeastern Minnesota, northern Missouri, and Wisconsin.

  12. Rescuing degrading aquifers in the Central Coastal Plain of North Carolina (USA): Just process, effective groundwater management policy, and sustainable aquifers

    Science.gov (United States)

    Manda, Alex K.; Klein, Wendy A.

    2014-07-01

    Strategic management of degrading coastal aquifers in eastern North Carolina (USA) became imperative after a severe imbalance occurred between withdrawal and recharge rates. To ameliorate this growing problem, an aggressive water policy was developed through public input by creating the Central Coastal Plain Capacity Use Area (CCPCUA) to maintain beneficial use of groundwater resources. Insights from social psychology, and socio-legal studies are used to evaluate how procedural justice and public participation played major roles to resolving groundwater resource management problems. A mixed methods approach uses archival data and interviews with various rule-making participants to assess the process of stakeholder involvement that led to creation of the policy. In addition, data analysis techniques are utilized to evaluate the effects of the policy on aquifer health (through water levels) over a ˜10 year period. Results suggest that not only did a stakeholder group participate in a process that was deemed fair, understandable, and relatively easy to administer for users and regulators, but public participation resulted in an effective plan that ensures the long-term sustainable use of groundwater. Declining groundwater withdrawals and recovering water levels suggest that the rule is achieving its intended goal of protecting the aquifers from depletion and degradation. This paper touches on global themes that are essential to water demand and consumption, water management techniques, and water resources protection.

  13. Effects of clay dispersion on aquifer storage and recovery in coastal aquifers

    Science.gov (United States)

    Konikow, L.F.; August, L.L.; Voss, C.I.

    2001-01-01

    Cyclic injection, storage, and withdrawal of freshwater in brackish aquifers is a form of aquifer storage and recovery (ASR) that can beneficially supplement water supplies in coastal areas. A 1970s field experiment in Norfolk, Virginia, showed that clay dispersion in the unconsolidated sedimentary aquifer occurred because of cation exchange on clay minerals as freshwater displaced brackish formation water. Migration of interstitial clay particles clogged pores, reduced permeability, and decreased recovery efficiency, but a calcium preflush was found to reduce clay dispersion and lead to a higher recovery efficiency. Column experiments were performed in this study to quantify the relations between permeability changes and clay mineralogy, clay content, and initial water salinity. The results of these experiments indicate that dispersion of montmorillonite clay is a primary contributor to formation damage. The reduction in permeability by clay dispersion may be expressed as a linear function of chloride content. Incorporating these simple functions into a radial, cross-sectional, variable-density, ground-water flow and transport model yielded a satisfactory simulation of the Norfolk field test - and represented an improvement over the model that ignored changes in permeability. This type of model offers a useful planning and design tool for ASR operations in coastal clastic aquifer systems.

  14. The impact of aquifer heterogeneity on the performance of aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Valstar, J.R.; Gaans, van P.; Grotenhuis, J.T.C.; Rijnaarts, H.

    2013-01-01

    Heterogeneity in hydraulic properties of the subsurface is not accounted for in current design calculations of aquifer thermal energy storage (ATES). However, the subsurface is heterogeneous and thus affects the heat distribution around ATES wells. In this paper, the influence of heterogeneity on th

  15. The impact of aquifer heterogeneity on the performance of aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Valstar, J.R.; Gaans, van P.; Grotenhuis, J.T.C.; Rijnaarts, H.

    2013-01-01

    Heterogeneity in hydraulic properties of the subsurface is not accounted for in current design calculations of aquifer thermal energy storage (ATES). However, the subsurface is heterogeneous and thus affects the heat distribution around ATES wells. In this paper, the influence of heterogeneity on

  16. Application of Multivariate Statistical Techniques for Characterization of Groundwater Quality in the Coastal Aquifer of Nador, Tipaza (Algeria)

    Science.gov (United States)

    Bouderbala, Abdelkader; Remini, Boualem; Saaed Hamoudi, Abdelamir; Pulido-Bosch, Antonio

    2016-06-01

    The study focuses on the characterization of the groundwater salinity on the Nador coastal aquifer (Algeria). The groundwater quality has undergone serious deterioration due to overexploitation. Groundwater samplings were carried out in high and low waters in 2013, in order to study the evolution of groundwater hydrochemistry from the recharge to the coastal area. Different kinds of statistical analysis were made in order to identify the main hydrogeochemical processes occurring in the aquifer and to discriminate between different groups of groundwater. These statistical methods provide a better understanding of the aquifer hydrochem-istry, and put in evidence a hydrochemical classification of wells, showing that the area with higher salinity is located close to the coast, in the first two kilometers, where the salinity gradually increases as one approaches the seaside and suggests the groundwater salinization by sea-water intrusion.

  17. Application of multivariate statistical techniques for characterization of groundwater quality in the coastal aquifer of Nador, Tipaza (Algeria

    Directory of Open Access Journals (Sweden)

    Bouderbala Abdelkader

    2016-06-01

    Full Text Available The study focuses on the characterization of the groundwater salinity on the Nador coastal aquifer (Algeria. The groundwater quality has undergone serious deterioration due to overexploitation. Groundwater samplings were carried out in high and low waters in 2013, in order to study the evolution of groundwater hydrochemistry from the recharge to the coastal area. Different kinds of statistical analysis were made in order to identify the main hydrogeochemical processes occurring in the aquifer and to discriminate between different groups of groundwater. These statistical methods provide a better understanding of the aquifer hydrochemistry, and put in evidence a hydrochemical classification of wells, showing that the area with higher salinity is located close to the coast, in the first two kilometers, where the salinity gradually increases as one approaches the seaside and suggests the groundwater salinization by seawater intrusion.

  18. Aquifer thermal energy (heat and chill) storage

    Energy Technology Data Exchange (ETDEWEB)

    Jenne, E.A. (ed.)

    1992-11-01

    As part of the 1992 Intersociety Conversion Engineering Conference, held in San Diego, California, August 3--7, 1992, the Seasonal Thermal Energy Storage Program coordinated five sessions dealing specifically with aquifer thermal energy storage technologies (ATES). Researchers from Sweden, The Netherlands, Germany, Switzerland, Denmark, Canada, and the United States presented papers on a variety of ATES related topics. With special permission from the Society of Automotive Engineers, host society for the 1992 IECEC, these papers are being republished here as a standalone summary of ATES technology status. Individual papers are indexed separately.

  19. SRP baseline hydrogeologic investigation: Aquifer characterization

    Energy Technology Data Exchange (ETDEWEB)

    Strom, R.N.; Kaback, D.S.

    1992-03-31

    An investigation of the mineralogy and chemistry of the principal hydrogeologic units and the geochemistry of the water in the principal aquifers at Savannah River Site (SRS) was undertaken as part of the Baseline Hydrogeologic Investigation. This investigation was conducted to provide background data for future site studies and reports and to provide a site-wide interpretation of the geology and geochemistry of the Coastal Plain Hydrostratigraphic province. Ground water samples were analyzed for major cations and anions, minor and trace elements, gross alpha and beta, tritium, stable isotopes of hydrogen, oxygen, and carbon, and carbon-14. Sediments from the well borings were analyzed for mineralogy and major and minor elements.

  20. Optimization of the Implementation of Managed Aquifer Recharge - Effects of Aquifer Heterogeneity

    Science.gov (United States)

    Maliva, Robert; Missimer, Thomas; Kneppers, Angeline

    2010-05-01

    Managed aquifer recharge (MAR) has become a key component of integrated water resources management, especially in water scarce regions. MAR can serve the dual role of increasing the supply of available water and improving the quality of recharged water through natural attenuation processes. The performance of MAR systems is highly dependent upon site-specific hydrogeological conditions. Aquifer heterogeneity, such as the presence of high-permeability preferential flow zones and dual or even the so-called triple-porosity conditions, has been responsible for the under performance or failure of some MAR systems. Aquifer heterogeneity can result in much more rapid and unpredictable movement and mixing of recharged water and the bypassing of natural attenuation processes. A critical element of MAR projects is a detailed aquifer characterization and the development of groundwater flow and solute transport models at the appropriate spatial and temporal scales that accurately simulate local heterogeneous flow systems. Geochemical modeling based on high-quality, site-specific mineralogical and water chemistry data can also be used to predict the potential for adverse water-rock interactions such as the leaching of arsenic and trace metals into recharged water. Hydrogeological conditions that could lead to poor system performance should be identified early in the project development before the investment is made to construct a full-scale system. Hydrogeological conditions that have lead to poor MAR system performance are typically identifiable at the exploratory well stage of projects. Early detection of adverse hydrogeological conditions provides an opportunity to either abandon a likely under-performing project, select an alternative site with more favorable conditions, or modify the system design to be more compatible with local hydrogeology. Advanced borehole geophysical techniques and workflow software can allow for enhanced aquifer characterization and thus allow for

  1. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Science.gov (United States)

    Becker, C.J.; Runkle, D.L.; Rea, Alan

    1997-01-01

    ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace aquifer encompasses the unconsolidated terrace deposits and alluvium associated with the North Fork of the Red River and the Red River in the western half of Tillman County. These sediments consist of discontinuous layers of clay, sandy clay, sand, and gravel. The aquifer extends over an area of 285 square miles and is used for irrigation and domestic purposes. Granite and the Hennessey Formation outcrop in northern parts of the aquifer where alluvial deposits are absent. These outcrops were included as part of the aquifer in a thesis that modeled the ground-water flow in the aquifer. Most of the aquifer boundaries and some of the lines in the hydraulic conductivity and recharge data sets were extracted from a published digital surficial geology data set based on a scale of 1:250,000. Most of the lines in the hydraulic conductivity, recharge, and 1969 water-level elevation contour data sets, and one line in the aquifer boundary data set were digitized from a paper map published at a scale of 1:249,695 in a thesis in which the ground-water flow in the aquifer was modeled. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  2. Replenishing an unconfined coastal aquifer to control seawater intrusion: Injection or infiltration?

    Science.gov (United States)

    Lu, Chunhui; Shi, Wenlong; Xin, Pei; Wu, Jichun; Werner, Adrian D.

    2017-06-01

    In this study, we compare the performances of well injection and pond infiltration in controlling seawater intrusion in an unconfined coastal aquifer through two scenario groups: (1) a single injection well versus an elliptic infiltration pond and (2) an injection-extraction well pair system versus an elliptic infiltration pond-extraction well system. Comparison is based on quantitative indicators that include the interface toe location, saltwater volume, and maximum net extraction rate (for scenario 2). We introduce a method to determine the maximum net extraction rate for cases where the locations of stagnation points cannot be easily derived. Analytical analysis shows that the performances of injection and infiltration are the same, provided that the pond shape is circular. The examination of scenario group 1 suggests that the shape of the infiltration pond has a minor effect on the interface toe location as well as the reduction in the saltwater volume, given the same total recharge rate. The investigation of scenario group 2 indicates, by contrast, that the maximum net extraction rate increases significantly with the increasing ratio of b to a, where a and b are semiaxes of the ellipse parallel and perpendicular to the coastline, respectively. Specifically, for a typical aquifer assumed, an increase of 40% is obtained for the maximum net extraction when b/a increases from 1/200 to 200. Despite that the study is based on a simplified model, the results provide initial guidance for practitioners when planning to use an aquifer recharge strategy to restore a salinized unconfined coastal aquifer.

  3. Decision Support System for Aquifer Recharge (AR) and Aquifer Storage and Recovery (ASR) Planning, Design, and Evaluation Decision Support System for Aquifer Recharge (AR) and Aquifer Storage and Recovery (ASR) Planning, Design, and Evaluation – Principles and Technical Basis

    Science.gov (United States)

    Aquifer recharge (AR) is a technical method being utilized to enhance groundwater resources through man-made replenishment means, such as infiltration basins and injections wells. Aquifer storage and recovery (ASR) furthers the AR techniques by withdrawal of stored groundwater at...

  4. Localized bedrock aquifer distribution explains discharge from a headwater catchment

    Science.gov (United States)

    Kosugi, Ken'ichirou; Fujimoto, Masamitsu; Katsura, Shin'ya; Kato, Hiroyuki; Sando, Yoshiki; Mizuyama, Takahisa

    2011-07-01

    Understanding a discharge hydrograph is one of the leading interests in catchment hydrology. Recent research has provided credible information on the importance of bedrock groundwater on discharge hydrographs from headwater catchments. However, intensive monitoring of bedrock groundwater is rare in mountains with steep topography. Hence, how bedrock groundwater controls discharge from a steep headwater catchment is in dispute. In this study, we conducted long-term hydrological observations using densely located bedrock wells in a headwater catchment underlain by granitic bedrock. The catchment has steep topography affected by diastrophic activities. Results showed a fairly regionalized distribution of bedrock aquifers within a scale of tens of meters, consisting of upper, middle, and lower aquifers, instead of a gradual and continuous decline in water level from ridge to valley bottom. This was presumably attributable to the unique bedrock structure; fault lines developed in the watershed worked to form divides between the bedrock aquifers. Spatial expanse of each aquifer and the interaction among aquifers were key factors to explain gentle and considerable variations in the base flow discharge and triple-peak discharge responses of the observed hydrograph. A simple model was developed to simulate the discharge hydrograph, which computed each of the contributions from the soil mantle groundwater, from the lower aquifer, and from the middle aquifer to the discharge. The modeling results generally succeeded in reproducing the observed hydrograph. Thus, this study demonstrated that understanding regionalized bedrock aquifer distribution is pivotal for explaining discharge hydrograph from headwater catchments that have been affected by diastrophic activities.

  5. Hydrologic Properties of Aquifers in the Central Savannah River Area

    Energy Technology Data Exchange (ETDEWEB)

    Snipes, D.S.; Benson, S.M.; Price Jr., Van; Temples, T.J.

    1996-01-02

    The hydrologic properties of selected aquifer systems underlying the Milhaven and Girard sites in Georgia were determined through a series of aquifer performance tests performed from October, 1994 to January, 1995. At the Milhaven site, the systems under investigation consisted of the upper, middle and lower components of the Upper Floridan, the lower Dublin, and the lower Midville aquifers. At the Dublin site, only the lower Dublin and lower Midville aquifers were tested. In addition, the hydrologic properties of the lower Midville aquifer underlying the P, B and D Areas at the Savannah River Site were determined by a series of aquifer tests conducted in 1993 and 1994. The tests generally consisted of collecting water level and atmospheric data for 24 hours followed by a 72 hour pump test and a subsequent 72 hour recovery period. These tests were designed to determine the aquifer properties over a large area, to determine whether any hydrologic boundaries existed in the area, and to find out if leakance could be induced through the confining units which separated the aquifer units.

  6. Aquifer Sampling Tube Results for Fiscal Year 2003

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, Mary J.; Peterson, Robert E.

    2003-10-27

    This report presents and discusses results of the fiscal year 2003 sampling event associated with aquifer tubes along the Columbia River in the northern Hanford Site. Aquifer tube data help define the extent of groundwater contamination near the river, determine vertical variations in contamination, monitor the performance of interim remedial actions near the river, and support impact studies.

  7. Hydraulic conductivity of a firn aquifer system in southeast Greenland

    Science.gov (United States)

    Miller, Olivia L.; Solomon, D. Kip; Miège, Clément; Koenig, Lora S.; Forster, Richard R.; Montgomery, Lynn N.; Schmerr, Nicholas; Ligtenberg, Stefan R. M.; Legchenko, Anatoly; Brucker, Ludovic

    2017-05-01

    Some regions of the Greenland ice sheet, where snow accumulation and melt rates are high, currently retain substantial volumes of liquid water within the firn pore space throughout the year. These firn aquifers, found between 10-30 m below the snow surface, may significantly affect sea level rise by storing or draining surface meltwater. The hydraulic gradient and the hydraulic conductivity control flow of meltwater through the firn. Here we describe the hydraulic conductivity of the firn aquifer estimated from slug tests and aquifer tests at six sites located upstream of Helheim Glacier in southeastern Greenland. We conducted slug tests using a novel instrument, a piezometer with a heated tip that melts itself into the ice sheet. Hydraulic conductivity ranges between 2.5x10-5 and 1.1x10-3 m/s. The geometric mean of hydraulic conductivity of the aquifer is 2.7x10-4 m/s with a geometric standard deviation of 1.4 from both depth specific slug tests (analyzed using the Hvorslev method) and aquifer tests during the recovery period. Hydraulic conductivity is relatively consistent between boreholes and only decreases slightly with depth. The hydraulic conductivity of the firn aquifer is crucial for determining flow rates and patterns within the aquifer, which inform hydrologic models of the aquifer, its relation to the broader glacial hydrologic system, and its effect on sea level rise.

  8. Hydraulic Conductivity of a Firn Aquifer in Southeast Greenland

    Directory of Open Access Journals (Sweden)

    Olivia L. Miller

    2017-05-01

    Full Text Available Some regions of the Greenland ice sheet, where snow accumulation and melt rates are high, currently retain substantial volumes of liquid water within the firn pore space throughout the year. These firn aquifers, found between ~10 and 30 m below the snow surface, may significantly affect sea level rise by storing or draining surface meltwater. The hydraulic gradient and the hydraulic conductivity control flow of meltwater through the firn. Here we describe the hydraulic conductivity of the firn aquifer estimated from slug tests and aquifer tests at six sites located upstream of Helheim Glacier in southeastern Greenland. We conducted slug tests using a novel instrument, a piezometer with a heated tip that melts itself into the ice sheet. Hydraulic conductivity ranges between 2.5 × 10−5 and 1.1 × 10−3 m/s. The geometric mean of hydraulic conductivity of the aquifer is 2.7 × 10−4 m/s with a geometric standard deviation of 1.4 from both depth specific slug tests (analyzed using the Hvorslev method and aquifer tests during the recovery period. Hydraulic conductivity is relatively consistent between boreholes and only decreases slightly with depth. The hydraulic conductivity of the firn aquifer is crucial for determining flow rates and patterns within the aquifer, which inform hydrologic models of the aquifer, its relation to the broader glacial hydrologic system, and its effect on sea level rise.

  9. Geohydrology of the Antlers aquifer (Cretaceous), southeastern Oklahoma

    Science.gov (United States)

    Hart, Donald L.; Davis, Robert E.

    1981-01-01

    The Antlers aquifer, which consists of as much as 900 feet of friable sandstone, silt, clay, and shale, crops out in an area of 1,860 square miles and underlies about 4,400 square miles in southeastern Oklahoma. Precipitation ranges from 35 to 50 inches per year across the outcrop area, which is well suited to allow high rates of infiltration. The aquifer contains an estimated 31,600,000 acre-feet of water having less than 1,000 milligrams per liter dissolved solids. The average saturated sand thickness is 250 feet. Aquifer tests in the confined part of the aquifer give an average storage coefficient of 0.0005 and an average transmissivity of 1,480 feet squared per day. The estimated specific yield of the unconfined part of the aquifer is 0.15; the transmissivity has not been determined. Large-capacity wells tapping the aquifer commonly yield 100 to 500 gallons per minute; the maximum measured yield is 1,700 gallons per minute. Water usage from the aquifer is very small owing to the availability of an abundance of surface water. Water quality throughout the central and northern part of the aquifer is generally acceptable for municipal use. A few wells, however, yield water containing concentrations of iron and manganese exceeding the limit recommended for municipal use by the National Academy of Sciences and National Academy of Engineering (1972).

  10. Aquifers switched from confined to semiconfined by earthquakes

    Science.gov (United States)

    Shi, Zheming; Wang, Guangcai

    2016-11-01

    Earthquake-induced aquifer parameter changes (e.g., permeability and hydraulic diffusivity) have been documented in many studies. However, changes in the confinement of an aquifer from confined to semiconfined following an earthquake have not been reported. Here we focus on the tidal response of the water level in four wells following the 2008 Wenchuan Mw 7.9 and 2013 Lushan Mw 6.6 earthquakes to show that earthquakes can change confined aquifers to semiconfined aquifers by reopening of preexisting vertical fractures (and later healing). This study has important implications because a switch from confined to semiconfined means a change of vertical hydraulic connection, which may affect the vulnerability of an aquifer, the integrity of underground waste repositories, and the safety of groundwater supplies.

  11. Aquifer overexploitation: what does it mean?

    Science.gov (United States)

    Custodio, Emilio

    2002-02-01

    Groundwater overexploitation and aquifer overexploitation are terms that are becoming common in water-resources management. Hydrologists, managers and journalists use them when talking about stressed aquifers or some groundwater conflict. Overexploitation may be defined as the situation in which, for some years, average aquifer ion rate is greater than, or close to the average recharge rate. But rate and extent of recharge areas are often very uncertain. Besides, they may be modified by human activities and aquifer development. In practice, however, an aquifer is often considered as overexploited when some persistent negative results of aquifer development are felt or perceived, such as a continuous water-level drawdown, progressive water-quality deterioration, increase of ion cost, or ecological damage. But negative results do not necessarily imply that ion is greater than recharge. They may be simply due to well interferences and the long transient period that follow changes in the aquifer water balance. Groundwater storage is depleted to some extent during the transient period after ion is increased. Its duration depends on aquifer size, specific storage and permeability. Which level of "aquifer overexploitation" is advisable or bearable, depends on the detailed and updated consideration of aquifer-development effects and the measures implemented for correction. This should not be the result of applying general rules based on some indirect data. Monitoring, sound aquifer knowledge, and calculation or modelling of behaviour are needed in the framework of a set of objectives and policies. They should be established by a management institution, with the involvement of groundwater stakeholders, and take into account the environmental and social constraints. Aquifer overexploitation, which often is perceived to be associated with something ethically bad, is not necessarily detrimental if it is not permanent. It may be a step towards sustainable development. Actually

  12. The surficial aquifer in Pinellas County, Florida

    Science.gov (United States)

    Causseaux, K.W.

    1985-01-01

    The surficial aquifer in Pinellas County, Florida, contains potable water throughout most of the county and is a potential source of water to augment the public supply that is presently imported from adjacent counties. The county accounts for 38 percent of the public supply consumption of ground water in the 11-county area of west-central Florida and 68 percent of this water is imported from two adjacent counties. The surficial aquifer has a saturated thickness of more than 30 feet throughout most of the county. Specific capacity per foot of screen for wells is less than 0.1 gallon per minute per foot of drawdown in some parts of the county, but yield is sufficient in most of the county for many small uses with shallow-well pumps. Minimum potential yield varies from 5 gallons per minute in the northern part of the county to more than 30 gallons per minute in the south. Concentrations of iron are high enough in parts of the county to cause staining. Chloride concentrations are less than 100 milligrams per liter in most of the county and do not pose a problem for many uses. (USGS)

  13. Evidence of Hydrogeological Connection between the Mountain and Plio-Plistocene Aquifer Systems, Using Pharmaceutical Residual- case study Jericho area/Lower Jordan Valley

    Science.gov (United States)

    Marei, Amer; Schmidt, Natali; Tiehm, Andreas

    2013-04-01

    Jericho Oases (-258 m b.s.l) is known through the history for its fertile soil, date trees, and sweet fruits. Groundwater is the only water sources for domestic and agricultural activities, where about 8 MCM/a discharge form three major springs groups, in addition to 20 MCM are taped from 45 shallow boreholes (10-180 m) in the Plio-Plistocene aquifer system. The current and future availability of groundwater of the shallow Plio-Plistocene aquifer system is the key factor for the economical development of agricultural sector, where during the last 10 years around 50 million USD are invested in this sector. Green houses agriculture, and date trees farming become the major groundwater consumers. From the hydrological point view, the study area is part of the eastern Wadi Al Quilt drainage system, where recharge take place along the mountain range in the western part of the catchment area. The shallow aquifer system consists of gravel; sand and silt inter fingering with clay layers. Chalk and chalky limestone formation of Senonian age separate the shallow aquifer from Mountain aquifer which consists of limestone, and dolomite. Both aquifer systems are part from the Eastern Basin where groundwater flows towards the Jordan River-Dead Sea basin. Direct recharge from rainfall to the shallow aquifer system is neglected due to the high evaporation rates, and only about 1 MCM/a of flooding water infiltrate into this aquifer. The hypotheses of this study is an indirect groundwater replenishment take places in certain sites along the N-S-major fault system, and groundwater flow through passages into the Plio-Plistocene aquifer systems. We tried to use pharmaceutical residuals to trace groundwater flow regimes in the Mountain and Plio-Plistocene aquifer system. Twenty eight water samples were collected during the hydrological year 2011 (in March and July) from 19 sampling sites (springs and boreholes). Few samples were collected from Al Bereh waste water treatment plant as well

  14. Hydrology and digital simulation of the regional aquifer system, eastern Snake River Plain, Idaho

    Science.gov (United States)

    Garabedian, S.P.

    1992-01-01

    The occurrence and movement of water in the regional aquifer system that underlies the eastern Snake River Plain, Idaho, de- pend on the transmissivity and storage capacity of rocks that compose the geologic framework and on the distribution and amount of recharge and discharge of water within that frame- work. On a regional scale, most water moves horizontally through interflow zones in Quaternary basalt of the Snake River Group. In recharge and discharge areas, water also moves vertically along joints and interfingering edges of basalt flows. Aquifer thickness is largely unknown, but geophysical studies suggest that locally the Quaternary basalt may exceed several thousand feet. Along the margins of the plain, sand and gravel several hundred feet thick transmit large volumes of water.

  15. Inferring Aquifer Transmissivity from River Flow Data

    Science.gov (United States)

    Trichakis, Ioannis; Pistocchi, Alberto

    2016-04-01

    Daily streamflow data is the measurable result of many different hydrological processes within a basin; therefore, it includes information about all these processes. In this work, recession analysis applied to a pan-European dataset of measured streamflow was used to estimate hydrogeological parameters of the aquifers that contribute to the stream flow. Under the assumption that base-flow in times of no precipitation is mainly due to groundwater, we estimated parameters of European shallow aquifers connected with the stream network, and identified on the basis of the 1:1,500,000 scale Hydrogeological map of Europe. To this end, Master recession curves (MRCs) were constructed based on the RECESS model of the USGS for 1601 stream gauge stations across Europe. The process consists of three stages. Firstly, the model analyses the stream flow time-series. Then, it uses regression to calculate the recession index. Finally, it infers characteristics of the aquifer from the recession index. During time-series analysis, the model identifies those segments, where the number of successive recession days is above a certain threshold. The reason for this pre-processing lies in the necessity for an adequate number of points when performing regression at a later stage. The recession index derives from the semi-logarithmic plot of stream flow over time, and the post processing involves the calculation of geometrical parameters of the watershed through a GIS platform. The program scans the full stream flow dataset of all the stations. For each station, it identifies the segments with continuous recession that exceed a predefined number of days. When the algorithm finds all the segments of a certain station, it analyses them and calculates the best linear fit between time and the logarithm of flow. The algorithm repeats this procedure for the full number of segments, thus it calculates many different values of recession index for each station. After the program has found all the

  16. Survival of bacterial indicators and the functional diversity of native microbial communities in the Floridan aquifer system, south Florida

    Science.gov (United States)

    Lisle, John T.

    2014-01-01

    The Upper Floridan aquifer in the southern region of Florida is a multi-use, regional scale aquifer that is used as a potable water source and as a repository for passively recharged untreated surface waters, and injected treated surface water and wastewater, industrial wastes, including those which contain greenhouse gases (for example, carbon dioxide). The presence of confined zones within the Floridan aquifer that range in salinity from fresh to brackish allow regulatory agencies to permit the injection of these different types of product waters into specific zones without detrimental effects to humans and terrestrial and aquatic ecosystems. The type of recharge that has received the most regulatory attention in south Florida is aquifer storage and recovery (ASR). The treated water, prior to injection and during recovery, must meet primary and secondary drinking water standards. The primary microbiology drinking water standard is total coliforms, which have been shown to be difficult to inactivate below the regulatory standard during the treatment process at some ASR facilities. The inefficient inactivation of this group of indicator bacteria permits their direct injection into the storage zones of the Floridan aquifer. Prior to this study, the inactivation rates for any member of the total coliform group during exposure to native geochemical conditions in groundwater from any zone of the Floridan aquifer had not been derived. Aboveground flow through mesocosms and diffusion chambers were used to quantify the inactivation rates of two bacterial indicators, Escherichia coli and Pseudomonas aeruginosa, during exposure to groundwater from six wells. These wells collect water from two ASR storage zones: the Upper Floridan aquifer (UFA) and Avon Park Permeable Zone (APPZ). Both bacterial strains followed a biphasic inactivation model. The E. coli populations had slower inactivation rates in the UFA (range: 0.217–0.628 per hour (h-1)) during the first phase of the

  17. Quality of water in the fractured-bedrock aquifer of New Hampshire

    Science.gov (United States)

    Moore, Richard Bridge

    2004-01-01

    Over the past few decades, New Hampshire has experienced considerable population growth, which is forcing some communities to look for alternative public and private water supplies in the bedrock aquifer. Because the quality of water from the aquifer can vary, the U.S. Geological Survey statistically analyzed well data from 1,353 domestic and 360 public-supply bedrock wells to characterize the ground water. The domestic-well data were from homeowner-collected samples analyzed by the New Hampshire Department of Environmental Services (NHDES) Environmental Laboratory from 1984 to 1994. Bedrock water in New Hampshire often contains high concentrations of iron, manganese, arsenic, and radon gas. Water samples from 21 percent of the domestic bedrock wells contained arsenic above the U.S. Environmental Protection Agency (USEPA) 10 micrograms per liter (?g/L) drinking-water standard for public-water supplies, and 96 percent had radon concentrations greater than the USEPA-proposed 300 picocurie per liter (pCi/L) standard for public-water supplies. Some elevated fluoride concentrations (2 percent of samples) were above the 4 milligrams per liter (mg/L) USEPA drinking-water standard for public-water supplies. Water from the bedrock aquifer also typically is soft to moderately hard, and has a pH greater than 7.0. Variations in bedrock water quality were discernable when the data were compared to lithochemical groupings of the bedrock, indicating that the type of bedrock has an effect on the quality of water in the bedrock aquifer of New Hampshire. Ground-water samples from the metasedimentary lithochemical group have greater concentrations of total iron and total manganese than do the felsic and mafic igneous lithochemical groups. Ground-water samples from the felsic igneous group have higher concentrations of total fluoride than do those from the other lithochemical groups. For arsenic, the calcareous metasedimentary group was identified, using the public-supply database, as

  18. Analytical results of a long-term aquifer test conducted near the Rio Grande, Albuquerque, New Mexico, with a section on piezometric-extensometric test results

    Science.gov (United States)

    Thorn, Conde R.; Heywood, Charles E.

    2001-01-01

    The City of Albuquerque, New Mexico, is interested in gaining a better understanding, both quantitative and qualitative, of the aquifer system in and around Albuquerque. Currently (2000), the City of Albuquerque and surrounding municipalities are completely dependent on ground-water reserves for their municipal water supply. This report presents the results of a long-term aquifer test conducted near the Rio Grande in Albuquerque. The long-term aquifer test was conducted during the winter of 1994-95. The City of Albuquerque Griegos 1 water production well was pumped continuously for 54 days at an average pumping rate of 2,331 gallons per minute. During the 54-day pumping and a 30-day recovery period, water levels were recorded in a monitoring network that consisted of 3 production wells and 19 piezometers located at nine sites. These wells and piezometers were screened in river alluvium and (or) the upper and middle parts of the Santa Fe Group aquifer system. In addition to the measurement of water levels, aquifer-system compaction was monitored during the aquifer test by an extensometer. Well-bore video and flowmeter surveys were conducted in the Griegos 1 water production well at the end of the recovery period to identify the location of primary water- producing zones along the screened interval. Analytical results from the aquifer test presented in this report are based on the methods used to analyze a leaky confined aquifer system and were performed using the computer software package AQTESOLV. Estimated transmissivities for the Griegos 1 and 4 water production wells ranged from 10,570 to 24,810 feet squared per day; the storage coefficient for the Griegos 4 well was 0.0025. A transmissivity of 13,540 feet squared per day and a storage coefficient of 0.0011 were estimated from the data collected from a piezometer completed in the production interval of the Griegos 1 well.

  19. Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system From Long Island, New York, to North Carolina

    Science.gov (United States)

    Masterson, John P.; Pope, Jason P.; Fienen, Michael N.; Monti, Jr., Jack; Nardi, Mark R.; Finkelstein, Jason S.

    2016-08-31

    balance the inflows was subdivided between streamflow, discharge to tidal portions of streams, and coastal discharge. The hydrologic budget developed for current [2013] conditions determined that 93 percent of the total outflow was to surface waters with about 70 percent divided evenly between streamflow and shallow coastal discharge and 23 percent as discharge to tidal waters. The remaining 7 percent of the total outflow components include withdrawals from both the surficial and confined aquifers of the groundwater system.The groundwater availability assessment of the NACP aquifer system highlights the importance of analyses at both the regional and local scales to understand how changes in land use, water use, and climate have affected groundwater resources and how these resources may change in the future. The investigation included assessments of the regional changes in water levels and budgets across State lines, the importance of considering storage change in the confining units, the response of the aquifer system to a continuation of current [2013] hydrologic stresses into the future, and the potential effects of climate change and sea-level rise on the aquifer system.The Potomac aquifer group includes two of the most widely used aquifers in the NACP aquifer system, the Potomac-Patapsco and Potomac-Patuxent regional aquifers, providing about 24 percent of the total groundwater used in the region. Withdrawals from large pumping centers in this deep, confined aquifer group have resulted in substantial decreases in water-levels across state lines, particularly between southern Virginia and northeastern North Carolina as well as between southern New Jersey and northern Delaware where water levels in the Potomac-Patapsco aquifer have decreased by as much as 200 ft and 50 ft, respectively from predevelopment to current [2013] conditions. This response in water levels also is reflected in changes in water budgets where, for example, about 20 percent of the total response

  20. Relationships Between Aquifer Properties and Microbial Populations in the Borden Aquifer

    DEFF Research Database (Denmark)

    Barbaro, Susan Elizabeth; Albrechtsen, Hans-Jørgen; Jensen, Bjorn K.

    1994-01-01

    , electron transport system (ETS) activity, dissolved oxygen (DO), dissolved organic carbon (DOC), weight fraction of organic carbon (FOC), and hydraulic conductivity (K) were determined for contiguous samples of aquifer material removed at 10.0-cm intervals from the 9 cores. Viable cell counts (0-10-4 cfu...... and activities were found to be predominantly correlated with depth and dissolved oxygen. Evaluation of these results revealed an oxygen threshold level, occurring at approximately 3.0 mg/L, below which bacterial populations isolated in this study were less able to proliferate. Further evaluation...... of the microbiological and geologic data collected in this study suggests that, in conjunction with low dissolved oxygen, the naturally occurring carbon may be unsuitable to support large numbers of microorganisms. Similarly, an increase in the production of INT-for when aquifer material was amended with nitrogen...

  1. Arsenic release from Floridan Aquifer rock during incubations simulating aquifer storage and recovery operations.

    Science.gov (United States)

    Jin, Jin; Zimmerman, Andrew R; Norton, Stuart B; Annable, Michael D; Harris, Willie G

    2016-05-01

    While aquifer storage and recovery (ASR) is becoming widely accepted as a way to address water supply shortages, there are concerns that it may lead to release of harmful trace elements such as arsenic (As). Thus, mechanisms of As release from limestone during ASR operations were investigated using 110-day laboratory incubations of core material collected from the Floridan Aquifer, with treatment additions of labile or refractory dissolved organic matter (DOM) or microbes. During the first experimental phase, core materials were equilibrated with native groundwater lacking in DO to simulate initial non-perturbed anaerobic aquifer conditions. Then, ASR was simulated by replacing the native groundwater in the incubations vessels with DO-rich ASR source water, with DOM or microbes added to some treatments. Finally, the vessels were opened to the atmosphere to mimic oxidizing conditions during later stages of ASR. Arsenic was released from aquifer materials, mainly during transitional periods at the beginning of each incubation stage. Most As released was during the initial anaerobic experimental phase via reductive dissolution of Fe oxides in the core materials, some or all of which may have formed during the core storage or sample preparation period. Oxidation of As-bearing Fe sulfides released smaller amounts of As during the start of later aerobic experimental phases. Additions of labile DOM fueled microbially-mediated reactions that mobilized As, while the addition of refractory DOM did not, probably due to mineral sorption of DOM that made it unavailable for microbial utilization or metal chelation. The results suggest that oscillations of groundwater redox conditions, such as might be expected to occur during an ASR operation, are the underlying cause of enhanced As release in these systems. Further, ASR operations using DOM-rich surface waters may not necessarily lead to additional As releases.

  2. Groundwater level responses to precipitation variability in Mediterranean insular aquifers

    Science.gov (United States)

    Lorenzo-Lacruz, Jorge; Garcia, Celso; Morán-Tejeda, Enrique

    2017-09-01

    Groundwater is one of the largest and most important sources of fresh water on many regions under Mediterranean climate conditions, which are exposed to large precipitation variability that includes frequent meteorological drought episodes, and present high evapotranspiration rates and water demand during the dry season. The dependence on groundwater increases in those areas with predominant permeable lithologies, contributing to aquifer recharge and the abundance of ephemeral streams. The increasing pressure of tourism on water resources in many Mediterranean coastal areas, and uncertainty related to future precipitation and water availability, make it urgent to understand the spatio-temporal response of groundwater bodies to precipitation variability, if sustainable use of the resource is to be achieved. We present an assessment of the response of aquifers to precipitation variability based on correlations between the Standardized Precipitation Index (SPI) at various time scales and the Standardized Groundwater Index (SGI) across a Mediterranean island. We detected three main responses of aquifers to accumulated precipitation anomalies: (i) at short time scales of the SPI (24 months). The differing responses were mainly explained by differences in lithology and the percentage of highly permeable rock strata in the aquifer recharge areas. We also identified differences in the months and seasons when aquifer storages are more dependent on precipitation; these were related to climate seasonality and the degree of aquifer exploitation or underground water extraction. The recharge of some aquifers, especially in mountainous areas, is related to precipitation variability within a limited spatial extent, whereas for aquifers located in the plains, precipitation variability influence much larger areas; the topography and geological structure of the island explain these differences. Results indicate large spatial variability in the response of aquifers to precipitation in

  3. Impact of multi-purpose aquifer utilisation on a variable-density groundwater flow system in the Gippsland Basin, Australia

    Science.gov (United States)

    Varma, Sunil; Michael, Karsten

    2012-02-01

    The Latrobe aquifer in the Gippsland Basin in southeastern Australia is a prime example for emerging resource conflicts in Australian sedimentary basins. The Latrobe Group forms a major freshwater aquifer in the onshore Gippsland Basin, and is an important reservoir for oil and gas in both onshore and offshore parts of the basin. The Latrobe Group and overlying formations contain substantial coal resources that are being mined in the onshore part of the basin. These may have coal-seam-gas potential and, in addition, the basin is considered prospective for its geothermal energy and CO2 storage potential. The impacts of groundwater extraction related to coal-mine dewatering, public water supply, and petroleum production on the flow of variable-density formation water has been assessed using freshwater hydraulic heads and impelling force vectors. Groundwater flows from the northern and western edges towards the central part of the basin. Groundwater discharge occurs mainly offshore along the southern margin. Post-stress hydraulic heads show significant declines near the petroleum fields and in the coal mining areas. A hydrodynamic model of the Latrobe aquifer was used to simulate groundwater recovery in the Latrobe aquifer from different scenarios of cessation of groundwater and other fluid extractions.

  4. Impact of Aquifer Heterogeneities on Autotrophic Denitrification.

    Science.gov (United States)

    McCarthy, A.; Roques, C.; Selker, J. S.; Istok, J. D.; Pett-Ridge, J. C.

    2015-12-01

    Nitrate contamination in groundwater is a big challenge that will need to be addressed by hydrogeologists throughout the world. With a drinking water standard of 10mg/L of NO3-, innovative techniques will need to be pursued to ensure a decrease in drinking water nitrate concentration. At the pumping site scale, the influence and relationship between heterogeneous flow, mixing, and reactivity is not well understood. The purpose of this project is to incorporate both physical and chemical modeling techniques to better understand the effect of aquifer heterogeneities on autotrophic denitrification. We will investigate the link between heterogeneous hydraulic properties, transport, and the rate of autotrophic denitrification. Data collected in previous studies in laboratory experiments and pumping site scale experiments will be used to validate the models. The ultimate objective of this project is to develop a model in which such coupled processes are better understood resulting in best management practices of groundwater.

  5. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Boesen, Carsten; Kristiansen, Henning;

    1991-01-01

    Nitrate distribution and reduction processes were investigated in an unconfined sandy aquifer of Quaternary age. Groundwater chemistry was studied in a series of eight multilevel samplers along a flow line, deriving water from both arable and forested land. Results show that plumes of nitrate...... processes of O2 and NO3- occur at rates that are fast compared to the rate of downward water transport. Nitrate-contaminated groundwater contains total contents of dissolved ions that are two to four times higher than in groundwater derived from the forested area. The persistence of the high content...... of total dissolved ions in the NO3- free anoxic zone indicates the downward migration of contaminants and that active nitrate reduction is taking place. Nitrate is apparently reduced to N2 because both nitrite and ammonia are absent or found at very low concentrations. Possible electron donors...

  6. Modeling contaminant plumes in fractured limestone aquifers

    DEFF Research Database (Denmark)

    Mosthaf, Klaus; Brauns, Bentje; Fjordbøge, Annika Sidelmann

    the established approaches of the equivalent porous medium, discrete fracture and dual continuum models. However, these modeling concepts are not well tested for contaminant plume migration in limestone geologies. Our goal was to develop and evaluate approaches for modeling the transport of dissolved contaminant...... in the planning of field tests and to update the conceptual model in an iterative process. Field data includes information on spill history, distribution of the contaminant (multilevel sampling), geology and hydrogeology. To describe the geology and fracture system, data from borehole logs, packer tests, optical...... distribution in the aquifer. Different models were used for the planning and interpretation of the pump and tracer test. The models were evaluated by examining their ability to describe collected field data. The comparison with data showed that the models have substantially different representations...

  7. Hydrogeology and water quality of the Floridan aquifer system and effect of Lower Floridan aquifer withdrawals on the Upper Floridan aquifer at Barbour Pointe Community, Chatham County, Georgia, 2013

    Science.gov (United States)

    Gonthier, Gerard J.; Clarke, John S.

    2016-06-02

    Two test wells were completed at the Barbour Pointe community in western Chatham County, near Savannah, Georgia, in 2013 to investigate the potential of using the Lower Floridan aquifer as a source of municipal water supply. One well was completed in the Lower Floridan aquifer at a depth of 1,080 feet (ft) below land surface; the other well was completed in the Upper Floridan aquifer at a depth of 440 ft below land surface. At the Barbour Pointe test site, the U.S. Geological Survey completed electromagnetic (EM) flowmeter surveys, collected and analyzed water samples from discrete depths, and completed a 72-hour aquifer test of the Floridan aquifer system withdrawing from the Lower Floridan aquifer.Based on drill cuttings, geophysical logs, and borehole EM flowmeter surveys collected at the Barbour Pointe test site, the Upper Floridan aquifer extends 369 to 567 ft below land surface, the middle semiconfining unit, separating the two aquifers, extends 567 to 714 ft below land surface, and the Lower Floridan aquifer extends 714 to 1,056 ft below land surface.A borehole EM flowmeter survey indicates that the Upper Floridan and Lower Floridan aquifers each contain four water-bearing zones. The EM flowmeter logs of the test hole open to the entire Floridan aquifer system indicated that the Upper Floridan aquifer contributed 91 percent of the total flow rate of 1,000 gallons per minute; the Lower Floridan aquifer contributed about 8 percent. Based on the transmissivity of the middle semiconfining unit and the Floridan aquifer system, the middle semiconfining unit probably contributed on the order of 1 percent of the total flow.Hydraulic properties of the Upper Floridan and Lower Floridan aquifers were estimated based on results of the EM flowmeter survey and a 72-hour aquifer test completed in Lower Floridan aquifer well 36Q398. The EM flowmeter data were analyzed using an AnalyzeHOLE-generated model to simulate upward borehole flow and determine the transmissivity of

  8. ENVIRONMENTAL AUDITING: An Aquifer Vulnerability Assessment of the Paluxy Aquifer, Central Texas, USA, Using GIS and a Modified DRASTIC Approach.

    Science.gov (United States)

    Fritch; McKnight; Yelderman; Arnold

    2000-03-01

    / The Paluxy aquifer in north-central Texas is composed primarily of Lower Cretaceous clastics. This aquifer provides water for both domestic and agricultural purposes in the region. The study area for this investigation incorporates the outcrop and recharge areas, as well as the confined and unconfined portions of the aquifer. The purpose of this investigation is to perform a groundwater vulnerability assessment on the Paluxy aquifer using the GRASS 4.1 geographic information system combined with a modified DRASTIC approach. DRASTIC is an acronym for the variables that control the groundwater pollution potential (Depth to water, net Recharge, Aquifer media, Soil media,Topography, Impact of the vadose zone, andConductivity of the aquifer). Using such an approach allows one to investigate the potential for groundwater contamination on a regional, rather than site-specific, scale. Based upon data from variables such as soil permeability, depth to water, aquifer hydraulic conductivity, and topography, subjective numerical weightings have been assigned according to the variable's relative importance in regional groundwater quality. The weights for each variable comprise a GIS map layer. These map layers are combined to formulate the final groundwater pollution potential map. Using this method of investigation, the pollution potential map for the study area classifies 47% of the area as having low pollution potential, 26% as having moderate pollution potential, 22% as having high pollution potential, and 5% as having very high pollution potential.

  9. Alpine Groundwater - Pristine Aquifers Under Threat?

    Science.gov (United States)

    Schneider, P.; Lange, A.

    2014-12-01

    Glacier and permafrost retreat are prominent climate change indicators. However, the characteristics of climate and hydrology in mountain areas remain poorly understood relative to lowland areas. Specifically, not much is known about alpine groundwater, its recharge and water quality variations, as these remote reservoirs are rarely monitored. As global temperatures rise, glaciers and permafrost will continue to retreat forming new sediment deposits and changing infiltration conditions in high alpine terrain. Climate change impacts the hydro-chemical composition of alpine waters, accelerates weathering processes, and potentially triggers mobilization of pollutants. Accordingly, we monitored groundwater quantity and quality parameters of an alpine porous aquifer near the Tiefenbach glacier in the Gotthard Massif in Switzerland. The goal of this research was to assess quality and seasonal storage dynamics of groundwater above the timberline (2000 m). To translate hydrological science into an ecosystem service context, we focused on four attributes: Water quantity: observations of groundwater level fluctuations combined with analysis of contributing water sources based on stable isotope analysis to give a quantitative understanding of origin and amount of water, Water quality: groundwater level, groundwater temperature and electrical conductivity were used as proxies for sampling of hydro-chemical parameters with automated water samplers during primary groundwater recharge periods (snowmelt and rainfall events), Location: Alpine terrain above the timberline, especially recharge into/out of an alpine porous aquifer at a pro-glacial floodplain and Date of annual melt (albedo effect) and timing of flow (snow- and icemelt from May to September) and groundwater recharge during the growing season. The study found that the summer groundwater temperatures depend on the date of annual melt and are more sensitive to climate forcing than lowland groundwater temperatures

  10. California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project--shallow aquifer assessment

    Science.gov (United States)

    ,

    2013-01-01

    The California State Water Resources Control Board’s (SWRCB) GAMA Program is a comprehensive assessment of statewide groundwater quality in California. From 2004 to 2012, the GAMA Program’s Priority Basin Project focused on assessing groundwater resources used for public drinking-water supplies. More than 2,000 public-supply wells were sampled by U.S. Geological Survey (USGS) for this effort. Starting in 2012, the GAMA Priority Basin Project began an assessment of water resources in shallow aquifers in California. These shallow aquifers provide water for domestic and small community-supply wells, which are often drilled to shallower depths in the groundwater system than public-supply wells. Shallow aquifers are of interest because shallow groundwater may respond more quickly and be more susceptible to contamination from human activities at the land surface, than the deeper aquifers. The SWRCB’s GAMA Program was developed in response to the Groundwater Quality Monitoring Act of 2001 (Water Code sections 10780-10782.3): a public mandate to assess and monitor the quality of groundwater resources used for drinking-water supplies, and to increase the availability of information about groundwater quality to the public. The U.S. Geological Survey is the technical lead of the Priority Basin Project. Stewardship of California’s groundwater resources is a responsibility shared between well owners, communities, and the State. Participants and collaborators in the GAMA Program include Regional Water Quality Control Boards, Department of Water Resources, Department of Public Health, local and regional groundwater management entities, county and local water agencies, community groups, and private citizens. Well-owner participation in the GAMA Program is entirely voluntary.

  11. Digital map of aquifer boundary for the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set represents the extent of the High Plains aquifer in the central United States. The extent of the High Plains aquifer covers 174,000 square...

  12. Hydrogeology - AQUIFER_SYSTEMS_UNCONSOLIDATED_IDNR_IN: Unconsolidated Aquifer Systems of Indiana (Indiana Department of Natural Resources, 1:48,000, Polygon Shapefile)

    Data.gov (United States)

    NSGIC State | GIS Inventory — AQUIFER_SYSTEMS_UNCONSOLIDATED_IDNR_IN is a polygon shapefile that shows unconsolidated aquifer systems of the state of Indiana at a scale of 1:48,000. The following...

  13. Hydrogeology - MO 2014 Thermoclines StFrancois Aquifer (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — St. Francois Aquifer thermo cline correlates the temperature data throughout the state in the Lower Cambrian Series, from the Bonneterre Formation to the Lamotte...

  14. Evaluation of the aquifer characteristic of Nanka Sands using ...

    African Journals Online (AJOL)

    Michael Horsfall

    ABSTRACT: In this study, we have coupled surface geophysical method with pumping test results to provide a cost effective and efficient alternative in aquifer parameter estimation. Vertical ... and hydraulic heads map in ARC GIST software.

  15. PRINCIPLES OF TREATING UNCONSOLIDATED AQUIFERS AND AN ENGINEERING INSTANCE

    Institute of Scientific and Technical Information of China (English)

    SHENBaohong; GENGDeyong; XUYanchunt; LIANGHuaiqin; YUCaiying; LIChengming; RUIPin

    1995-01-01

    Based on practical experience of coal mining beneath water bodies, unconsolidated aquifers are divided into 5 types with Fuzzy theory. A suitable treatment method for each type of water body is given. An engineering instance is introduced.

  16. Polluted aquifers: identification and characterisation by statistical analysis.

    Science.gov (United States)

    Boemo, Analía; Musso, Haydée; Lomniczi, Irene

    2010-01-01

    Hierarchical clustering and principal component analysis applied to chemical components and physicochemical properties of well water proved to be a useful tool for identification and characterisation of aquifers. Underground water of Lerma Valley (Salta, Argentina) was examined for its physical and chemical properties by sampling 46 wells located in two adjacent areas separated by hills, one of them polluted with boron since 1991. Hierarchical clustering splits sampled sites into two main clusters, corresponding to the two areas, establishing the fact that the aquifers should be considered as two different entities in spite of their common recharge area. Values of boron concentration in the eastern area decreased in most of the wells since the pollution sources were eradicated, while four of them experienced a substantial increase, proof of the slow self-recovery of the aquifer. The use of principal component analysis provided evidence of the incipient boron pollution of the aquifer of the western area.

  17. Bioremediation of chlorinated ethenes in aquifer thermal energy storage

    NARCIS (Netherlands)

    Ni, Z.

    2015-01-01

      Subjects: bioremediation; biodegradation; environmental biotechnology, subsurface and groundwater contamination; biological processes; geochemistry; microbiology The combination of enhanced natural attenuation (ENA) of chlorinated volatile organic compounds (CVOCs) and aquife

  18. Functional Microbial Diversity Explains Groundwater Chemistry in a Pristine Aquifer

    Science.gov (United States)

    Microbial communities inhabiting anoxic aquifers catalyze critical biogeochemical reactions in the subsurface, yet little is known about how their community structure correlates with groundwater chemistry. In this study, we described the composition of microbial communities in th...

  19. Source speciation resolving hydrochemical complexity of coastal aquifers.

    Science.gov (United States)

    Sonkamble, Sahebrao; Chandra, Subash; Ahmed, Shakeel; Rangarajan, R

    2014-01-15

    There is a growing concern of seawater intrusion to freshwater aquifers due to groundwater overexploitation in the eastern coastal belt of Southern India. The problem becomes complex in the regions where industrial effluents are also contaminating the freshwater aquifers. In order to understand the hydrochemical complexity of the system, topographic elevation, static water level measurements, major ion chemistry, ionic cross plots, water type contours and factor analysis were applied for 144 groundwater samples of shallow and deep sources from Quaternary and Tertiary coastal aquifers, located within the industrial zone of 25 km(2) area near Cuddalore, Southern India. The ionic cross plots indicates dissolution of halite minerals from marine sources and seawater mixing into inland aquifers up to the level of 9.3%. The factor analysis explains three significant factors totaling 86.3% of cumulative sample variance which includes varying contribution from marine, industrial effluent and freshwater sources.

  20. Delineated Aquifer Boundaries of the Lake Tahoe Basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data present a ground-water inventory of existing geospatial data and other information needed to determine the extent and characteristics of the aquifers in...

  1. Hydrogeologic Areas of the Southwest Principal Aquifer (SWPA) study

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster dataset represents the boundaries of the hydrogeologic areas of the Southwest Principal Aquifer (SWPA) study of the National Water Quality Assessment...

  2. New York and New England carbonate-rock aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the New York and New England carbonate-rock aquifers in the states of New York, Vermont, Maine, Massachusetts, Connecticut,...

  3. Saturated thickness of the Minnelusa aquifer, Black Hills, South Dakota.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a polygon coverage created in ARC/INFO that represents the saturated thickness of the Minnelusa aquifer, Black Hills area, South Dakota. The...

  4. Saturated thickness of the Madison aquifer, Black Hills, South Dakota.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a polygon coverage created in ARC/INFO that represents the saturated thickness of the Madison aquifer, which includes the entire thickness of the...

  5. Intrinsic and enhanced biodegradation of benzene in strongly reduced aquifers

    NARCIS (Netherlands)

    Heiningen, W.N.M. van; Rijnaarts, H.H.M; Langenhoff, A.A.M.

    1999-01-01

    Laboratory microcosm studies were performed to examine intrinsic and enhanced benzene bioremediation using five different sediment and groundwater samples from three deeply anaerobic aquifers sited in northern Netherlands. The influence of addition of nitrate, sulfate, limited amounts of oxygen, and

  6. Bioremediation of chlorinated ethenes in aquifer thermal energy storage

    NARCIS (Netherlands)

    Ni, Z.

    2015-01-01

      Subjects: bioremediation; biodegradation; environmental biotechnology, subsurface and groundwater contamination; biological processes; geochemistry; microbiology The combination of enhanced natural attenuation (ENA) of chlorinated volatile organic compounds (CVOCs) and aquife

  7. Sole Source Aquifer Program | Drinking Water in New ...

    Science.gov (United States)

    2017-07-06

    The Safe Drinking Water Act gives EPA the authority to designate aquifers which are the sole or principal drinking water source for an area, and which, if contaminated, would create a significant hazard to public health.

  8. Functional Microbial Diversity Explains Groundwater Chemistry in a Pristine Aquifer

    Science.gov (United States)

    Microbial communities inhabiting anoxic aquifers catalyze critical biogeochemical reactions in the subsurface, yet little is known about how their community structure correlates with groundwater chemistry. In this study, we described the composition of microbial communities in th...

  9. Integrated characterisation of aquifer heterogeneity and landfill leachate plume migration

    Science.gov (United States)

    Tremblay, L.; Lefebvre, R.; Gloaguen, E.; Paradis, D.

    2009-05-01

    The understanding of groundwater flow and contaminant migration is based on our ability to characterize aquifers and represent these processes with numerical simulators. This understanding is required to efficiently remediate contaminated sites since the failure of remediation actions are often related to an insufficient understanding of aquifer heterogeneity. During the last decades, continuous development of numerical simulators allowed models to better represent complex flow systems. However, conventional hydrogeological characterization methods do not provide the data required to define aquifer heterogeneity. An original hydrogeological characterization approach was used to define aquifer heterogeneity and delineate landfill leachate plumes through the use and integration of varied techniques. The objective of the study is to develop a methodology to integrate hydrogeological, geophysical and geochemical data using geostatistical tools. The characterization program aims to better characterize the aquifer, delineate leachate plumes emitted by a former landfill, and guide a study of the natural attenuation of the plumes. The initial phase of the integrated multidisciplinary aquifer characterization program was carried out in a 12 km2 area of the sub-watershed surrounding the landfill of St-Lambert-de-Lauzon, Québec. In the study area, a 10-m thick sandy unconfined aquifer overlies clayey silt and till layers. In this relatively flat area, natural streams as well as agricultural and forestry drainage networks control groundwater flow. The first phase of the project focused on a regional hydrogeological and geochemical characterization where 5 field methods were combined: 1) surface geophysics (ground penetrating radar and electrical tomography) (GPR); 2) direct-push methods including a) cone penetration tests (CPT), b) soil sampling and c) installation of full- screened observation wells; 3) multilevel measurement of geochemical parameters and groundwater

  10. FEWA: a Finite Element model of Water flow through Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, G.T.; Huff, D.D.

    1983-11-01

    This report documents the implementation and demonstration of a Finite Element model of Water flow through Aquifers (FEWA). The particular features of FEWA are its versatility and flexibility to deal with as many real-world problems as possible. Point as well as distributed sources/sinks are included to represent recharges/pumpings and rainfall infiltrations. All sources/sinks can be transient or steady state. Prescribed hydraulic head on the Dirichlet boundaries and fluxes on Neumann or Cauchy boundaries can be time-dependent or constant. Source/sink strength over each element and node, hydraulic head at each Dirichlet boundary node, and flux at each boundary segment can vary independently of each other. Either completely confined or completely unconfined aquifers, or partially confined and partially unconfined aquifers can be dealt with effectively. Discretization of a compound region with very irregular curved boundaries is made easy by including both quadrilateral and triangular elements in the formulation. Large-field problems can be solved efficiently by including a pointwise iterative solution strategy as an optional alternative to the direct elimination solution method for the matrix equation approximating the partial differential equation of groundwater flow. FEWA also includes transient flow through confining leaky aquifers lying above and/or below the aquifer of interest. The model is verified against three simple cases to which analytical solutions are available. It is then demonstrated by two examples of how the model can be applied to heterogeneous and anisotropic aquifers with transient boundary conditions, time-dependent sources/sinks, and confining aquitards for a confined aquifer of variable thickness and for a free surface problem in an unconfined aquifer, respectively. 20 references, 25 figures, 8 tables.

  11. Virtual groundwater transfers from overexploited aquifers in the United States.

    Science.gov (United States)

    Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J

    2015-07-14

    The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km(3), 9.18 km(3), and 6.81 km(3), respectively, which is comparable to the capacity of Lake Mead (35.7 km(3)), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use.

  12. Saline aquifer mapping project in the southeastern United States

    Science.gov (United States)

    Williams, Lester J.; Spechler, Rick M.

    2011-01-01

    In 2009, the U.S. Geological Survey initiated a study of saline aquifers in the southeastern United States to evaluate the potential use of brackish or saline water from the deeper portions of the Floridan aquifer system and the underlying Coastal Plain aquifer system (Fig. 1). The objective of this study is to improve the overall understanding of the available saline water resources for potential future development. Specific tasks are to (1) develop a digital georeferenced database of borehole geophysical data to enable analysis and characterization of saline aquifers (see locations in Fig. 1), (2) identify and map the regional extent of saline aquifer systems and describe the thickness and character of hydrologic units that compose these systems, and (3) delineate salinity variations at key well sites and along section lines to provide a regional depiction of the freshwater-saltwater interfaces. Electrical resistivity and induction logs, coupled with a variety of different porosity logs (sonic, density, and neutron), are the primary types of borehole geophysical logs being used to estimate the water quality in brackish and saline formations. The results from the geophysical log calculations are being compared to available water-quality data obtained from water wells and from drill-stem water samples collected in test wells. Overall, the saline aquifer mapping project is helping to improve the understanding of saline water resources in the area. These aquifers may be sources of large quantities of water that could be treated by using reverse osmosis or similar technologies, or they could be used for aquifer storage and recovery systems.

  13. Virtual groundwater transfers from overexploited aquifers in the United States

    Science.gov (United States)

    Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J.

    2015-01-01

    The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km3, 9.18 km3, and 6.81 km3, respectively, which is comparable to the capacity of Lake Mead (35.7 km3), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use. PMID:26124137

  14. Baseline Scotland : the Lower Devonian aquifer of Strathmore

    OpenAIRE

    O Dochartaigh, B.E.; Smedley, P. L.; MacDonald, A M; Darling, W. G.

    2006-01-01

    This report presents a summary of the groundwater chemistry of the Devonian sedimentary aquifer in Strathmore, eastern Scotland. The area covered by this study extends from Perth in the southwest to Stonehaven in the northeast. The survey forms part of the ongoing Baseline Scotland project. The Devonian sedimentary rocks of Strathmore form an important regional aquifer in an area of some of the most fertile agricultural land in Scotland, with a number of major urban settleme...

  15. Virtual groundwater transfers from overexploited aquifers in the United States

    Science.gov (United States)

    Marston, L.; Konar, M.; Cai, X.; Troy, T.

    2015-12-01

    The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km3, 9.18 km3, and 6.81 km3, respectively, which is comparable to the capacity of Lake Mead (35.7 km3), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use.

  16. Critical stress scenarios for a coastal aquifer in southeastern Italy

    Directory of Open Access Journals (Sweden)

    C. Cherubini

    2011-05-01

    Full Text Available Over the last years the sustainable management of coastal water resources has become strategic, especially in southern Salento Peninsula (Apulia, where mal-performing management strategies adopted, together with the vulnerability of the hydrogeological system, have given rise to the deterioration of groundwater quality due to saltwater intrusion.

    In the study area there is the presence of multilevel shallow aquifer and a deep aquifer that interact by means of faults. The geological system is highly vulnerable to seawater intrusion so there is the need to adopt management strategies to avoid seawater intrusion phenomena. Nevertheless there is a lack of studies that analyze the methodology for the correct exploitation if the water resource in order to avoid further intrusion phenomena.

    This paper combines a density-driven, flow numerical model (Seawat v.4 with a fault conceptual and hydrologic model to simulate saltwater intrusion phenomenon in the deep as well as in the shallow aquifer of the Salento area. By means of the individuation of an indicator parameter of groundwater quality, it has been possible to simulate different scenarios of exploitation and therefore to define critical stress scenarios for both aquifers.

    The results show that the deep aquifer is more vulnerable than the shallow one, which means that in the former, in order not to reach conditions of contamination, a lower density of wells is necessary than in the latter.

    The reduction of well density coupled with the artificial recharge of freshwater into the aquifer may be proposed as a solution strategy to protect the aquifer.

    Therefore, future developments of the present study will be represented by the simulation of different scenarios of recharging to inhibit the saltwater intrusion front further inland. The proposed methodology and its future developments can represent an empirical tool to provide preliminary guidelines for long

  17. Landscape irrigation management for maintaining an aquifer and economic returns.

    Science.gov (United States)

    Kovacs, Kent Forrest; Mancini, Mattia; West, Grant

    2015-09-01

    Expanding irrigated agriculture and dryer climatic conditions has led to large-scale withdrawals of groundwater and the decline in shallow aquifers. Policy makers must wrestle with the challenge of maintaining economic growth while conserving the groundwater resource. A spatially explicit landscape level model analyzes consequences of optimally chosen crop mix patterns on an aquifer and economic returns. The model of the groundwater use incorporates irrigation needs of the crops grown, initial aquifer thickness, hydro-conductivity of the aquifer, and distance to surrounding grid cells. The economic model incorporates the site specific yield, crop mix, and irrigation practice investments to predict economic returns. A tradeoff occurs between the volume of the aquifer and economic returns due to groundwater withdrawal for irrigation, but the farm's ability to grow profitable lower irrigation crops dampens the intensity of this tradeoff. Allowing for multiple unconventional irrigation practices that are yield increasing and water conserving significantly increases the economic returns of a given crop mix while maintaining the aquifer.

  18. Stochastic modeling of a lava-flow aquifer system

    Science.gov (United States)

    Cronkite-Ratcliff, Collin; Phelps, Geoffrey A.

    2014-01-01

    This report describes preliminary three-dimensional geostatistical modeling of a lava-flow aquifer system using a multiple-point geostatistical model. The purpose of this study is to provide a proof-of-concept for this modeling approach. An example of the method is demonstrated using a subset of borehole geologic data and aquifer test data from a portion of the Calico Hills Formation, a lava-flow aquifer system that partially underlies Pahute Mesa, Nevada. Groundwater movement in this aquifer system is assumed to be controlled by the spatial distribution of two geologic units—rhyolite lava flows and zeolitized tuffs. The configuration of subsurface lava flows and tuffs is largely unknown because of limited data. The spatial configuration of the lava flows and tuffs is modeled by using a multiple-point geostatistical simulation algorithm that generates a large number of alternative realizations, each honoring the available geologic data and drawn from a geologic conceptual model of the lava-flow aquifer system as represented by a training image. In order to demonstrate how results from the geostatistical model could be analyzed in terms of available hydrologic data, a numerical simulation of part of an aquifer test was applied to the realizations of the geostatistical model.

  19. Transient solutions to groundwater mounding in bounded and unbounded aquifers.

    Science.gov (United States)

    Korkmaz, Serdar

    2013-01-01

    In this study, the well-known Hantush solution procedure for groundwater mounding under infinitely long infiltration strips is extended to finite and semi-infinite aquifer cases. Initially, the solution for infinite aquifers is presented and compared to those available in literature and to the numerical results of MODFLOW. For the finite aquifer case, the method of images, which is commonly used in well hydraulics, is used to be able to represent the constant-head boundaries at both sides. It is shown that a finite number of images is enough to obtain the results and sustain the steady state. The effect of parameters on the growth of the mound and on the time required to reach the steady state is investigated. The semi-infinite aquifer case is emphasized because the growth of the mound is not symmetric. As the constant-head boundary limits the growth, the unbounded side grows continuously. For this reason, the groundwater divide shifts toward the unbounded side. An iterative solution procedure is proposed. To perform the necessary computations a code was written in Visual Basic of which the algorithm is presented. The proposed methodology has a wide range of applicability and this is demonstrated using two practical examples. The first one is mounding under a stormwater dispersion trench in an infinite aquifer and the other is infiltration from a flood control channel into a semi-infinite aquifer. Results fit very well with those of MODFLOW.

  20. Characterizating Multi-layered Coastal Aquifer using Pneumatic Slug Tests

    Science.gov (United States)

    Malama, B.; Abere, M.; Mikenna, M.

    2016-12-01

    Results of pneumatic slug tests conducted in a monitoring wells of a shallow aquifer on the California Central Coast are presented. The aquifer is in the Los Osos groundwater basin on the California Central Coast, a semi-closed near-triangular groundwater basin bounded to the north and south by impermeable igneousbed rock and to the west by the Pacific Ocean. The groundwater basin is a multi-layered system comprising a perched, near-surface semi-confined, and a deep confined aquifer. The unincorporated community of Los Osos is wholly dependent on the groundwater basin that is threatened with seawater intrusion and nitratecontamination. The slug tests reported here were performed in the perched and semi-confined aquifers as part of a seawater intrusion characterization study. The semi-confined and confined aquifers show evidence of seawater intrusion with upconing in some deep aquifer municipal wells. The upconing has beeninterpreted by previous studies as evidence of preferential flow through a high permeability channel. The objective of the work was to test this hypothesis by mapping the horizontal and vertical spatial variability of hydraulic parameters across the basin and establish the extent of the high permeability unit.Here only preliminary results of slug tests conducted across the basin for vertically averaged hydraulic parameters are reported. The results provide an indication of the horizontal variability of hydraulic parameters. An additional study will be performed to characterize the vertical variability to investigate the probableexistsence of a high permeability channel.

  1. Multiscale characterization of a heterogeneous aquifer using an ASR operation.

    Science.gov (United States)

    Pavelic, Paul; Dillon, Peter J; Simmons, Craig T

    2006-01-01

    Heterogeneity in the physical properties of an aquifer can significantly affect the viability of aquifer storage and recovery (ASR) by reducing the recoverable proportion of low-salinity water where the ambient ground water is brackish or saline. This study investigated the relationship between knowledge of heterogeneity and predictions of solute transport and recovery efficiency by combining permeability and ASR-based tracer testing with modeling. Multiscale permeability testing of a sandy limestone aquifer at an ASR trial site showed that small-scale core data give lower-bound estimates of aquifer hydraulic conductivity (K), intermediate-scale downhole flowmeter data offer valuable information on variations in K with depth, and large-scale pumping test data provide an integrated measure of the effective K that is useful to constrain ground water models. Chloride breakthrough and thermal profiling data measured during two cycles of ASR showed that the movement of injected water is predominantly within two stratigraphic layers identified from the flowmeter data. The behavior of the injectant was reasonably well simulated with a four-layer numerical model that required minimal calibration. Verification in the second cycle achieved acceptable results given the model's simplicity. Without accounting for the aquifer's layered structure, high precision could be achieved on either piezometer breakthrough or recovered water quality, but not both. This study demonstrates the merit of an integrated approach to characterizing aquifers targeted for ASR.

  2. Radon in Groundwater of the Northeastern Gran Canaria Aquifer

    Directory of Open Access Journals (Sweden)

    Héctor Alonso

    2015-05-01

    Full Text Available 222Rn has been detected in 28 groundwater samples from the northeast of Gran Canaria (Canary Islands, Spain utilizing a closed loop system consisting of an AlphaGUARD monitor that measures radon activity concentration in the air by means of an ionization chamber, and an AquaKIT set that transfers dissolved radon in the water samples to the air within the circuit. Radon concentration in the water samples studied varies between 0.3 and 76.9 Bq/L. Spanish radiological protection regulations limit the concentration of 222Rn for drinking water to 100 Bq/L, therefore the values obtained for all the analyzed samples are below this threshold. The hydrogeological study reveals a significant correspondence between the radon activity concentration and the material characteristics of the aquifer. For a selected group of samples with high radon concentrations, gross alpha activity has been determined to have values higher than the prescriptive screening level (0.1 Bq/L.

  3. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant hydraulic conductivity values for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The...

  4. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant recharge values for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace and...

  5. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace and...

  6. Mapping global vulnerability index in mining sectors: A case study Moulares-Redayef aquifer system, southwestern Tunisia

    Science.gov (United States)

    Khelif, Nadia; Jmal, Ikram; Bouri, Salem

    2016-09-01

    Contrary to the DRASTIC model grouping together the saturated and unsaturated zones to compute a global intrinsic vulnerability index, the global vulnerability index method incorporates both hydrogeological and hydrochemical data for a comprehensive index mapping for the saturated zones. This concept depends on the behavior and the uses of the groundwater. The main aim of this study is to propose a scientific basis for sustainable land use planning and groundwater management of the Moulares-Reayef aquifer, located in Southwestern Tunisia. The overexploitation of this aquifer causes the threat of groundwater quality by various sources of pollution. The global vulnerability index was applied in the Moulares-Reayef aquifer. The results show that the most favorable zones to pollutant percolation are situated along the wadis (Tabaddit, Zallaz, Berka, …) which are drained by continuous discharges. The global vulnerability values were correlated with nitrates values for validation. It revealed a significant correlation showing that high values of nitrates occurred in highly vulnerable zones with a value of 0.69 for the Pearson coefficient. The global vulnerability evaluation shows that the aquifer is characterized by high vertical vulnerability and high susceptibility.

  7. Nitrate probability mapping in the northern aquifer alluvial system of the river Tagus (Portugal) using Disjunctive Kriging.

    Science.gov (United States)

    Mendes, Maria Paula; Ribeiro, Luís

    2010-02-01

    The Water Framework Directive and its daughter directives recognize the urgent need to adopt specific measures against the contamination of water by individual pollutants or a group of pollutants that present a significant risk to the quality of water. Probability maps showing that the nitrate concentrations exceed a legal threshold value in any location of the aquifer are used to assess risk of groundwater quality degradation from intensive agricultural activity in aquifers. In this paper we use Disjunctive Kriging to map the probability that the Nitrates Directive limit (91/676/EEC) is exceeded for the Nitrate Vulnerable Zone of the River Tagus alluvium aquifer. The Tagus alluvial aquifer system belongs to one of the most productive hydrogeological unit of continental Portugal and it is used to irrigate crops. Several groundwater monitoring campaigns were carried out from 2004 to 2006 according to the summer crops cycle. The study reveals more areas on the west bank with higher probabilities of contamination by nitrates (nitrate concentration values above 50mg/L) than on the east bank. The analysis of synthetic temporal probability map shows the areas where there is an increase of nitrates concentration during the summers.

  8. Hydrochemical Regions of the Glacial Aquifer System, Northern United States, and Their Environmental and Water-Quality Characteristics

    Science.gov (United States)

    Arnold, Terri L.; Warner, Kelly L.; Groschen, George E.; Caldwell, James P.; Kalkhoff, Stephen J.

    2008-01-01

    The glacial aquifer system in the United States is a large (953,000 square miles) regional aquifer system of heterogeneous composition. As described in this report, the glacial aquifer system includes all unconsolidated geologic material above bedrock that lies on or north of the line of maximum glacial advance within the United States. Examining ground-water quality on a regional scale indicates that variations in the concentrations of major and minor ions and some trace elements most likely are the result of natural variations in the geologic and physical environment. Study of the glacial aquifer system was designed around a regional framework based on the assumption that two primary characteristics of the aquifer system can affect water quality: intrinsic susceptibility (hydraulic properties) and vulnerability (geochemical properties). The hydrochemical regions described in this report were developed to identify and explain regional spatial variations in ground-water quality in the glacial aquifer system within the hypothetical framework context. Data analyzed for this study were collected from 1991 to 2003 at 1,716 wells open to the glacial aquifer system. Cluster analysis was used to group wells with similar ground-water concentrations of calcium, chloride, fluoride, magnesium, potassium, sodium, sulfate, and bicarbonate into five unique groups. Maximum Likelihood Classification was used to make the extrapolation from clustered groups of wells, defined by points, to areas of similar water quality (hydrochemical regions) defined in a geospatial model. Spatial data that represented average annual precipitation, average annual temperature, land use, land-surface slope, vertical soil permeability, average soil clay content, texture of surficial deposits, type of surficial deposit, and potential for ground-water recharge were used in the Maximum Likelihood Classification to classify the areas so the characteristics of the hydrochemical regions would resemble the

  9. Successful implementation of ASR in basalt-hosted aquifers in the Pacific Northwest of the United States

    Energy Technology Data Exchange (ETDEWEB)

    Eatom, L.; Melady, J.; Tolan, T.

    2009-07-01

    Despite the Pacific Northwest's reputation for being wet, many cities west and east of the Cascade Range in the United States of America find it increasingly difficult to meet peak water supply demand during the dry summer months. Aquifers in the east side of Oregon and Washington are the primary water supply sources for a vast agriculture industry, and they have experienced significant declines prompting regulatory restrictions. For these reasons, municipalities west and east of the Cascade Range, as well as agricultural interests have opted to implement aquifer storage and recovery (ASR) projects as a unique water management technique to help meet peak summer water demands. Unique to the Pacific Northwest are the Miocene-age continental flood-basalt flows of the Columbia River Basalt Group (CRBG), which consists of a thick, a really extensive series of extraordinarily huge lava flows. The CRBG plays host to an extensive regional aquifer system in eastern Washington, eastern Oregon, and western Oregon. The two ASR projects discussed in this paper, the City of Beaverton and Madison Farms, use CRBG aquifers to host their ASR projects. Since 1999, the City of Beaverton (City), Oregon, population 85,500, has installed three ASR wells hosted in the CRBG aquifer. Currently, the City stores approximately 1,703,000 cubic meters of treated drinking water annually with its ASR wells. The three wells can provide up to about 22,700 cubic meters per day of peaking capacity, which is equivalent to 35 percent of the City's summer peak day demand. Favorable hydrogeologic response and significant economic savings have made the City's ASR system immensely successful. Since 2006, Madison Farms, a 71-square-kilometer farm near Echo, Oregon, has been using ASR to increase summer pumping capacity from the CRBG. Unlike the City of Beaverton, which uses treated river water to recharge the CRBG aquifer, Madison Farms uses untreated shallow alluvial groundwater to recharge

  10. Data from core analyses, aquifer testing, and geophysical logging of Denver Basin bedrock aquifers at Castle Pines, Colorado

    Science.gov (United States)

    Robson, S.G.; Banta, E.R.

    1993-01-01

    This report contains data pertaining to the geologic and hydrologic characteristics of the bedrock aquifers of the Denver basin at a site near Castle Pines, Colorado. Data consist of a lithologic- description of about 2,400 ft of drill core and laboratory determinations of mineralogy, grain size, bulk and grain density, porosity, specific yield, and specific retention for selected core samples. Water-level data, atmospheric-pressure measurements, aquifer-compression measurements, and borehole geophysical logs also are included.

  11. Characterisation of river-aquifer exchange fluxes: The role of spatial patterns of riverbed hydraulic conductivities

    Science.gov (United States)

    Tang, Q.; Kurtz, W.; Brunner, P.; Vereecken, H.; Hendricks Franssen, H.-J.

    2015-12-01

    Interactions between surface water and groundwater play an essential role in hydrology, hydrogeology, ecology, and water resources management. A proper characterisation of riverbed structures might be important for estimating river-aquifer exchange fluxes. The ensemble Kalman filter (EnKF) is commonly used in subsurface flow and transport modelling for estimating states and parameters. However, EnKF only performs optimally for MultiGaussian distributed parameter fields, but the spatial distribution of streambed hydraulic conductivities often shows non-MultiGaussian patterns, which are related to flow velocity dependent sedimentation and erosion processes. In this synthetic study, we assumed a riverbed with non-MultiGaussian channel-distributed hydraulic parameters as a virtual reference. The synthetic study was carried out for a 3-D river-aquifer model with a river in hydraulic connection to a homogeneous aquifer. Next, in a series of data assimilation experiments three different groups of scenarios were studied. In the first and second group of scenarios, stochastic realisations of non-MultiGaussian distributed riverbeds were inversely conditioned to state information, using EnKF and the normal score ensemble Kalman filter (NS-EnKF). The riverbed hydraulic conductivity was oriented in the form of channels (first group of scenarios) or, with the same bimodal histogram, without channelling (second group of scenarios). In the third group of scenarios, the stochastic realisations of riverbeds have MultiGaussian distributed hydraulic parameters and are conditioned to state information with EnKF. It was found that the best results were achieved for channel-distributed non-MultiGaussian stochastic realisations and with parameter updating. However, differences between the simulations were small and non-MultiGaussian riverbed properties seem to be of less importance for subsurface flow than non-MultiGaussian aquifer properties. In addition, it was concluded that both En

  12. Arsenic control during aquifer storage recovery cycle tests in the Floridan Aquifer.

    Science.gov (United States)

    Mirecki, June E; Bennett, Michael W; López-Baláez, Marie C

    2013-01-01

    Implementation of aquifer storage recovery (ASR) for water resource management in Florida is impeded by arsenic mobilization. Arsenic, released by pyrite oxidation during the recharge phase, sometimes results in groundwater concentrations that exceed the 10 µg/L criterion defined in the Safe Drinking Water Act. ASR was proposed as a major storage component for the Comprehensive Everglades Restoration Plan (CERP), in which excess surface water is stored during the wet season, and then distributed during the dry season for ecosystem restoration. To evaluate ASR system performance for CERP goals, three cycle tests were conducted, with extensive water-quality monitoring in the Upper Floridan Aquifer (UFA) at the Kissimmee River ASR (KRASR) pilot system. During each cycle test, redox evolution from sub-oxic to sulfate-reducing conditions occurs in the UFA storage zone, as indicated by decreasing Fe(2+) /H2 S mass ratios. Arsenic, released by pyrite oxidation during recharge, is sequestered during storage and recovery by co-precipitation with iron sulfide. Mineral saturation indices indicate that amorphous iron oxide (a sorption surface for arsenic) is stable only during oxic and sub-oxic conditions of the recharge phase, but iron sulfide (which co-precipitates arsenic) is stable during the sulfate-reducing conditions of the storage and recovery phases. Resultant arsenic concentrations in recovered water are below the 10 µg/L regulatory criterion during cycle tests 2 and 3. The arsenic sequestration process is appropriate for other ASR systems that recharge treated surface water into a sulfate-reducing aquifer.

  13. First-order shallow aquifer characteristics across Europe: The International Hydrogeological Map of Europe at scale 1:1.5 Million (IHME1500)

    Science.gov (United States)

    Günther, Andreas; Duscher, Klaus; Broda, Stefan; Clos, Patrick; Reichling, Jörg

    2017-04-01

    Since the mid of the last century, pan-European hydrogeological overview-mapping is conducted at the scale 1 : 1.5 Million following common standards and guidelines to interpret suitable geologic mapping units in terms of potential uppermost aquifer (or non-aquifer) characteristics. These comprises potential aquifer productivities and general hydrogeological aquifer conditions (fissured vs. porous). The printed IHME1500 dataset successively elaborated and published from 1970 - 2013 consists of 25 individual map sheets. Besides the potential aquifer characterization grouped in six classes, IHME1500 offers a complete coverage of lithological material properties of potential shallow aquifer assemblages, and tracelines of major fault structures. Regional information on groundwater surfaces, aquifer thicknesses and depths, locations and characteristics of groundwater springs and other punctual information related to European groundwater resources is present for some areas in selected map sheets, however not digitally available. Synoptic IHME1500 vector data consists of a topographically corrected, seamless and harmonized polygon layer with attribute information on potential aquifer productivity and lithology. While the standardized aquifer-classification is relatively easy to harmonize across the entire mapped area, the lithological information of IHME1500 is presented using sheet-specific legend information resulting in more than 1000 aquifer lithology classes. An attempt was made to harmonize this information utilizing a specifically developed taxonomic scheme, treating consolidated, partly consolidated and unconsolidated materials separately. The translation of the original lithological information into this scheme allows for a hierarchical grouping of the mapping units into five generalization levels, where the highest aggregation level displays a ternary map showing the distribution of consolidated, partially consolidated and unconsolidated aquifer materials. The

  14. Groundwater Exploration in Freshwater/Saline Layered Aquifers - Southern Bangladesh.

    Science.gov (United States)

    McKelvey, P. A.; Rahman, M.

    2001-05-01

    A major urban water supply and sanitation project is being implemented in the southern coastal districts of Bangladesh, by the Governments of Bangladesh and Denmark (DPHE/DANIDA). Due to the poor quality and reliability of surface water in the coastal districts, the source for these schemes will be groundwater. However, the abstraction of large quantities of water is complicated by the fact that the shallow aquifers are thin and of poor hydraulic quality. In addition, there is saline water underlying the shallow aquifer and, in recent years, arsenic has been discovered in many shallow wells throughout Bangladesh. Over the majority of the coastal districts, a thick freshwater sand underlies the saline aquifers, at depths below 200 m. This freshwater unit is bounded by thick clays which protect it from overlying and underlying saline water. The deep aquifer has been exploited in some of the project towns but in a few areas no freshwater aquifers had been located. An exploration programme was undertaken in each of these towns to prove the location of the freshwater sands and to help plan the location and depth of production well drilling. The first exploration stage was to locate any existing deep hand pumped wells and to carry out a water quality survey. Generally, this was sufficient to prove the existence of a thick freshwater aquifer. However, exact well depths and geological data were usually lacking and an exploration well was usually required. In three of the project towns, no deep aquifers had been exploited by existing hand pumped wells and geophysical surveys were undertaken to identify the locations of freshwater aquifers. These surveys comprised resistivity sounding both within the towns and in outlying areas within a feasible pumping distance. In two cases, freshwater aquifers were inferred from the geophysical surveys and exploration drilling was undertaken to prove the resource. Exploration drilling was undertaken by local contractors using hand

  15. Microbial diversity in a hydrocarbon- and chlorinated-solvent- contaminated aquifer undergoing intrinsic bioremediation

    Science.gov (United States)

    Dojka, M.A.; Hugenholtz, P.; Haack, S.K.; Pace, N.R.

    1998-01-01

    A culture-independent molecular phylogenetic approach was used to survey constituents of microbial communities associated with an aquifer contaminated with hydrocarbons (mainly jet fuel) and chlorinated solvents undergoing intrinsic bioremediation. Samples were obtained from three redox zones: methanogenic, methanogenic-sulfate reducing, and iron or sulfate reducing. Small-subunit rRNA genes were amplified directly from aquifer material DNA by PCR with universally conserved or Bacteria- or Archaea-specific primers and were cloned. A total of 812 clones were screened by restriction fragment length polymorphisms (RFLP), approximately 50% of which were unique. All RFLP types that occurred more than once in the libraries, as well as many of the unique types, were sequenced. A total of 104 (94 bacterial and 10 archaeal) sequence types were determined. Of the 94 bacterial sequence types, 10 have no phylogenetic association with known taxonomic divisions and are phylogenetically grouped in six novel division level groups (candidate divisions WS1 to WS6); 21 belong to four recently described candidate divisions with no cultivated representatives (OPS, OP8, OP10, and OP11); and 63 are phylogenetically associated with 10 well-recognized divisions. The physiology of two particularly abundant sequence types obtained from the methanogenic zone could be inferred from their phylogenetic association with groups of microorganisms with a consistent phenotype. One of these sequence types is associated with the genus Syntrophus; Syntrophus spp. produce energy from the anaerobic oxidation of organic acids, with the production of acetate and hydrogen. The organism represented by the other sequence type is closely related to Methanosaeta spp., which are known to be capable of energy generation only through aceticlastic methanogenesis. We hypothesize, therefore, that the terminal step of hydrocarbon degradation in the methanogenic zone of the aquifer is aceticlastic methanogenesis and

  16. Inorganic carbon cycle in soil-rock-groundwater system in karst and fissured aquifers

    Directory of Open Access Journals (Sweden)

    Ajda Koceli

    2013-12-01

    Full Text Available The paper presents a systematic analysis of the isotopic composition of carbon (δ13CCaCO3 in carbonate rocks in central Slovenia, representing karst and fissured aquifers, and share of carbon contributions from carbonate dissolution and degradation of organic matter in aquifers, calculated from the mass balance equation. 59 samples of rocks (mainly dolomites from Upper Permian to Upper Triassic age were analyzed. Samples of carbonate rocks were pulverized and ground to fraction of 45 μm and for determination of δ13CCaCO3 analyzed with mass spectrometer for analyses of stable isotopes of light elements-IRMS. The same method was used for determination of isotopic composition of dissolved inorganic carbon (δ13CDIC in groundwater for 54 of 59 locations. Values of δ13CCaCO3 are in the range from -2.0 ‰ to +4.1 ‰, with an average δ13CCaCO3 value of +2.2 ‰. These values are typical for marine carbonates with δ13CCaCO3 around 0 ‰, although δ13CCaCO3 values differ between groups depending on the origin and age. Early diagenetic dolomites have relatively higher values of δ13CCaCO3 compared to other analyzed samples. The lowest values of δ13CCaCO3 were observed in Cordevolian and Bača dolomite, probably due to late diagenesis, during which meteoric water with lower isotopic carbon composition circulated in the process of sedimentation. Values of δ13CDIC range from -14.6 ‰ to -8.2 ‰. Higher δ13CDIC values (-8.2 ‰ indicate a low proportion of soil CO2 in the aquifer and rapid infiltration, while lower values (-14.6 ‰ indicate higher proportion of soil CO2 in the aquifer and slower infiltration. Calculated contributions of carbon from organic matter / dissolution of carbonates in the karstic and fissured aquifers s how a similar proportion (50 % : 50 %.

  17. Free web-based modelling platform for managed aquifer recharge (MAR) applications

    Science.gov (United States)

    Stefan, Catalin; Junghanns, Ralf; Glaß, Jana; Sallwey, Jana; Fatkhutdinov, Aybulat; Fichtner, Thomas; Barquero, Felix; Moreno, Miguel; Bonilla, José; Kwoyiga, Lydia

    2017-04-01

    Managed aquifer recharge represents a valuable instrument for sustainable water resources management. The concept implies purposeful infiltration of surface water into underground for later recovery or environmental benefits. Over decades, MAR schemes were successfully installed worldwide for a variety of reasons: to maximize the natural storage capacity of aquifers, physical aquifer management, water quality management, and ecological benefits. The INOWAS-DSS platform provides a collection of free web-based tools for planning, management and optimization of main components of MAR schemes. The tools are grouped into 13 specific applications that cover most relevant challenges encountered at MAR sites, both from quantitative and qualitative perspectives. The applications include among others the optimization of MAR site location, the assessment of saltwater intrusion, the restoration of groundwater levels in overexploited aquifers, the maximization of natural storage capacity of aquifers, the improvement of water quality, the design and operational optimization of MAR schemes, clogging development and risk assessment. The platform contains a collection of about 35 web-based tools of various degrees of complexity, which are either included in application specific workflows or used as standalone modelling instruments. Among them are simple tools derived from data mining and empirical equations, analytical groundwater related equations, as well as complex numerical flow and transport models (MODFLOW, MT3DMS and SEAWAT). Up to now, the simulation core of the INOWAS-DSS, which is based on the finite differences groundwater flow model MODFLOW, is implemented and runs on the web. A scenario analyser helps to easily set up and evaluate new management options as well as future development such as land use and climate change and compare them to previous scenarios. Additionally simple tools such as analytical equations to assess saltwater intrusion are already running online

  18. Finding a way to optimize drilling depths in clastic aquifers for geothermal energy

    Science.gov (United States)

    van Putten, M.; van Wees, J. D. A. M.; Pluymaekers, M. P. D.; Kramers, L.

    2012-04-01

    Clastic aquifers generally are marked by decreasing porosity and associated permeability with depth. Uncertainties in porosity of a few percentages can result in an order of magnitude change in permeability. Further, temperature increases with depth and is marked by an uncertainty of about 10-20%. Monte Carlo performance calculations, adopting variable temperature and porosity distributions, along with other natural uncertainties and engineering options for drilling, show that performance in doublet power and levelized costs of energy (LCOE in EUR/GJ) is most sensitive to changes in the temperature gradient and the porosity. As the temperature increases with depth while the porosity decreases with depth, these relationships show a trade-off in performance, such that a theoretical optimal depth can be found for a specific temperature gradient and porosity-depth curve, and associated porosity-permeability relationship. The optimal drilling depth is at the depth level where the LCOE are minimal. In mature oil and gas basin areas, such as the Netherlands, it is possible to obtain relationships of porosity and underlying permeability as a function of depth. Therefore, the applicability for establishing and using an optimal depth has been tested for a clastic aquifer in the Rotliegend stratigraphic group in the Netherlands. This aquifer has high geothermal potential and is subject to many exploration activities. Temperature gradient and porosity-depth trends (and underlying uncertainties) for this aquifer have been adopted from the national geothermal information system ThermoGIS (www.thermogis.nl). For the performance calculation of doublet power and LCOE an in-house techno-economical performance assessment (TEPA) tool called DoubletCalc has been used. The results show that optimal depth corresponds to a pronounced and sharp minimum in LCOE. Its depth depends strongly on the actual porosity-depth relationship and ranges between 1.5 and 3 km. Remarkably, variations in

  19. The economics of aquifer storage recovery technology

    Energy Technology Data Exchange (ETDEWEB)

    David, R.; Pyne, G.

    2014-10-01

    Aquifer storage recovery (ASR) technology is increasingly being utilized around the world for storing water underground through one or more wells during wet months and other times when water is available for storage. The water is then recovered from the same wells when needed to meet a growing variety of water supply objectives. The economics of ASR constitute the principal reason for its increasing utilization. ASR unit capital costs are typically less than half those of other water supply and water storage alternatives. Unit operating costs are usually only slightly greater than for conventional production well-fields. Marginal costs for ASR storage and recovery provide a powerful tool for making more efficient use of existing infrastructure, providing water supply sustainability and reliability at relatively low cost. The opportunity exists for a careful analysis of the net present value of ASR well-fields, addressing not only the associated capital and operating costs but also the value of the benefits achieved for each of the water supply objectives at each site. (Author)

  20. Commercialization of aquifer thermal energy storage technology

    Energy Technology Data Exchange (ETDEWEB)

    Hattrup, M.P.; Weijo, R.O.

    1989-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the US Department of Energy's (DOE) Office of Energy Storage and Distribution. The purpose of the study was to develop and screen a list of potential entry market applications for aquifer thermal energy storage (ATES). Several initial screening criteria were used to identify promising ATES applications. These include the existence of an energy availability/usage mismatch, the existence of many similar applications or commercial sites, the ability to utilize proven technology, the type of location, market characteristics, the size of and access to capital investment, and the number of decision makers involved. The in-depth analysis identified several additional screening criteria to consider in the selection of an entry market application. This analysis revealed that the best initial applications for ATES are those where reliability is acceptable, and relatively high temperatures are allowable. Although chill storage was the primary focus of this study, applications that are good candidates for heat ATES were also of special interest. 11 refs., 3 tabs.

  1. Soil aquifer treatment using advanced primary effluent

    KAUST Repository

    Sharma, Saroj K.

    2011-08-01

    Soil aquifer treatment (SAT) using primary effluent (PE) is an attractive option for wastewater treatment and reuse in many developing countries with no or minimal wastewater treatment. One of the main limitations of SAT of PE is rapid clogging of the infiltration basin due to high suspended solid concentrations. Some pre-treatment of PE before infiltration is likely to reduce this limitation, improve performance of SAT and help to implement this technology effectively. The effects of three pre-treatment options namely sedimentation (SED), coagulation (COAG) and horizontal roughing filtration (HRF) on SAT were analyzed by conducting laboratory-scale batch and soil column experiments. The sedimentation and coagulation pre-treatments led to less head loss development and reduction of clogging effect. The head loss development in soil column using PE + COAG and PE + SED was reduced by 85 and 72%, respectively, compared to PE alone without any pretreatment. The overall dissolved organic carbon (DOC) removal of pre-treatments and soil column collectively were 34, 44, 51 and 43.5% for PE without any pre-treatment, PE + SED, PE+ COAG and PE + HRF, respectively. Coagulation pre-treatment of PE was found to be the most effective option in terms of suspended solids, DOC and nitrogen removal. Sedimentation pre-treatment of PE could be attractive where land is relatively less expensive for the construction of sedimentation basins. © IWA Publishing 2011.

  2. Anthropogenic contaminants as tracers in an urbanizing karst aquifer

    Science.gov (United States)

    Mahler, Barbara; Massei, Nicolas

    2007-04-01

    Karst aquifers are uniquely vulnerable to contamination. In the Barton Springs segment of the karstic Edwards aquifer (Texas, U.S.A.), urban contaminants such as pesticides and volatile organic compounds frequently are detected in spring base flow. To determine whether contaminant concentrations change in response to storms, and if they therefore might act as tracers of focused recharge, samples were collected from Barton Springs at closely spaced intervals following three storms. Two herbicides (atrazine and simazine), two insecticides (carbaryl and diazinon), and a solvent (tetrachloroethene) described breakthrough curves over a 1-week period following one or more storms. The breakthrough curves were decomposed into two to five log-normal subcurves, which were interpreted as representing pulses of contaminants moving through the aquifer. Each subcurve could be used in the same way as an artificial tracer to determine travel time to and recovery at the spring. The contaminants have several advantages over artificial tracers: they represent the actual compounds of interest, they are injected essentially simultaneously at several points, and they are injected under those conditions when transport is of the most interest, i.e., following storms. The response of storm discharge, specific conductance, and contaminant loading at the spring depended on initial aquifer flow conditions, which varied from very low (spring discharge of 0.48 m 3/s) to high (spring discharge of 2.7 m 3/s): concentrations and recovery were the highest when initial aquifer flow conditions were low. This behavior provides information about aquifer structure and the influence of aquifer flow condition on transport properties.

  3. Managed Aquifer Recharge Using Treated Wastewater: An Option to Manage a Coastal Aquifer In Oman For Better Domestic Water Supply

    Science.gov (United States)

    Al-Maktoumi, Ali; Zekri, Slim; ElRawy, Mustafa

    2016-04-01

    Arid countries, such as the Sultanate of Oman, are facing challenges of water shortages threatening economic development and social stability. Most of those countries are vulnerable to the potential adverse impacts of climate change, the most significant of which are increased average temperatures, less and more erratic precipitation, sea level rise, and desertification. The combined effect of existing adverse conditions and likely impacts of future climate change will make water management even more difficult than what it is today. Tremendous efforts have been devoted to augment the water resources. Managed Aquifer Recharge (MAR) is practiced widely to store water during periods of surpluses and withdraw during deficits from an aquifer. In Muscat, there will be a surplus of >100,000 m3/day of TWW during winter months in the coming few years. The aquifer along the northern coast of Oman (Al-Khawd Aquifer) is conducive for MAR. Data show that TWW volumes will increase from 7.6 Mm3 in 2003 to 70.9 Mm3 in 2035 in Muscat city only. This study assesses, using MODFLOW 2005 numerical code, the impact of MAR using TWW on better management of the Al-Khawd unconfined coastal aquifer for better urban water supply. Specifically, aiming to maximize withdrawals from the domestic wells with minimize adverse effect of seawater intrusion. The model operates under a number of constrains that minimize the loss to the sea and the injected TWW must not migrates upstream (due to developed mound) and reach the wellfields used for domestic supply. The hypothetical injection wells are located downstream the domestic wellfield zone. The results of different managerial scenarios show that MAR produces a hydraulic barrier that decelerates the seawater intrusion which allows higher abstraction of pristine water from the upstream part of the aquifer. MAR along with redistribution/relocation of public wells allows abstraction of 2 times the current abstraction rate (around 6 Mm3/year to 12 Mm3

  4. Hydrogeologic framework of the Wood River Valley aquifer system, south-central Idaho

    Science.gov (United States)

    Bartolino, James R.; Adkins, Candice B.

    2012-01-01

    The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Hailey, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system, which consists primarily of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on groundwater for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the groundwater resource. As part of an ongoing U.S. Geological Survey effort to characterize the groundwater resources of the Wood River Valley, this report describes the hydrogeologic framework of the Wood River Valley aquifer system. Although most of the Wood River Valley aquifer system is composed of Quaternary-age sediments and basalts of the Wood River Valley and its tributaries, older igneous, sedimentary, or metamorphic rocks that underlie these Quaternary deposits also are used for water supply. It is unclear to what extent these rocks are hydraulically connected to the main part of Wood River Valley aquifer system and thus whether they constitute separate aquifers. Paleozoic sedimentary rocks in and near the study area that produce water to wells and springs are the Phi Kappa and Trail Creek Formations (Ordovician and Silurian), the Milligen Formation (Devonian), and the Sun Valley Group including the Wood River Formation (Pennsylvanian-Permian) and the Dollarhide Formation (Permian). These sedimentary rocks are intruded by granitic rocks of the Late Cretaceous Idaho batholith. Eocene Challis Volcanic Group rocks overlie all of the older rocks (except where removed by erosion). Miocene Idavada Volcanics are found in the southern part of the study area. Most of these rocks have been folded, faulted, and

  5. Analyzing microbial and sediment geochemistry to identify safe aquifer zones in an Arsenic prone aquifer

    Science.gov (United States)

    Kibria, G.; Hossain, M.; Kirk, M. F.; Bhattacharya, P.; Ahmed, K.; Datta, S.

    2013-12-01

    The assessment of the incidence of arsenic (As) and other oxyanions was examined in Bengal delta floodplain groundwaters from Matlab Upazila, Bangladesh. Our field campaign in 2013 covered an area of ~400km2 between North and South Matlab. Shallow tubewells except those installed within off-white sediments are mostly contaminated with high As. In our field studies we found the wells installed within light grey medium sand, the As concentration was found below 50μg/L. Groundwater abstracted from oxidized reddish sediments in contrast to reduced greyish sediments, contain significantly lower amount of dissolved As and can be a source of safe water. Sediment geochemistry and adsorption extent of oxidized red brown and reduced grey sediments to attenuate As are studied here. Sediment cores were collected at regular intervals from within depth of ~125m in Matlab. This study describes the color, lithofacies and mineralogy of the sediments The stable isotopes of groundwaters from various depths within a piezometer nest are studied also to determine the extent of hydraulic conductivity between depths of aquifers along with mechanism of recharge of the groundwater at those depths. DNA recovered from Matlab core samples averaged 450ng/g from course-grained samples and 800ng/g from fine-grained samples. After sequencing the DNA, it was found that microbial community in red or light gray sediments are different than gray-dark gray sediments (e.g. Burkholderiaceae and Pseudomonadacee are common in grey/ dark gray sediment but Streptomycetaceae is common in red/ light grey color). Rhodocyclaceae, Aeromonadaceae, Shewanellaceae are the common genera present in these sediments that are capable of reducing Fe in this aquifer environment. Synchrotron aided μXANES and μXRD studies conducted for solid state As and S speciation in the core samples at different depths indicate the occurrences of hotspots of As differently distributed in red-brown and grey sediments. Samples collected

  6. Factors affecting public-supply well vulnerability in two karst aquifers.

    Science.gov (United States)

    Musgrove, MaryLynn; Katz, Brian G; Fahlquist, Lynne S; Crandall, Christy A; Lindgren, Richard J

    2014-09-01

    Karst aquifers occur in a range of climatic and geologic settings. Nonetheless, they are commonly characterized by their vulnerability to water-quality impairment. Two karst aquifers, the Edwards aquifer in south-central Texas and the Upper Floridan aquifer in western Florida, were investigated to assess factors that control the movement of contaminants to public-supply wells (PSWs). The geochemistry of samples from a selected PSW or wellfield in each aquifer was compared with that from nearby monitoring wells and regional PSWs. Geochemistry results were integrated with age tracers, flow modeling, and depth-dependent data to refine aquifer conceptual models and to identify factors that affect contaminant movement to PSWs. The oxic Edwards aquifer is vertically well mixed at the selected PSW/wellfield, although regionally the aquifer is geochemically variable downdip. The mostly anoxic Upper Floridan aquifer is affected by denitrification and also is geochemically variable with depth. In spite of considerable differences in geology and hydrogeology, the two aquifers are similarly vulnerable to anthropogenic contamination. Vulnerability in studied PSWs in both aquifers is strongly influenced by rapid karst flowpaths and the dominance of young (aquifers (nitrate, atrazine, deethylatrazine, tetrachloroethene, and chloroform). Specific consideration of water-quality protection efforts, well construction and placement, and aquifer response times to land-use changes and contaminant loading are discussed, with implications for karst groundwater management.

  7. Superimposed Pristine Limestone Aquifers with Marked Hydrochemical Differences Exhibit Distinct Fungal Communities

    Science.gov (United States)

    Nawaz, Ali; Purahong, Witoon; Lehmann, Robert; Herrmann, Martina; Küsel, Kirsten; Totsche, Kai U.; Buscot, François; Wubet, Tesfaye

    2016-01-01

    Fungi are one important group of eukaryotic microorganisms in a diverse range of ecosystems, but their diversity in groundwater ecosystems is largely unknown. We used DNA-based pyro-tag sequencing of the fungal internal transcribed spacer (ITS) rDNA gene to investigate the presence and community structure of fungi at different sampling sites of two superimposed limestone aquifers ranging from 8.5 to 84 m depth in the newly established Hainich Critical Zone Exploratory (Hainich CZE). We detected a diversity of fungal OTUs in groundwater samples of all sampling sites. The relative percentage abundance of Basidiomycota was higher in the upper aquifer assemblage, whilst Ascomycota dominated the lower one. In parallel to differences in the hydrochemistry we found distinct fungal communities at all sampling sites. Classification into functional groups revealed an overwhelming majority of saprotrophs. Finding taxa common to all analyzed groundwater sites, point to a groundwater specific fungal microbiome. The presence of different functional groups and, in particular plant and cattle pathogens that are not typical of subsurface habitats, suggests links between the surface and subsurface biogeosphere due to rapid transportation across the fracture networks typical of karstic regions during recharge episodes. However, further studies including sampling series extended in both time and space are necessary to confirm this hypothesis. PMID:27242696

  8. Aquifer test at well SMW-1 near Moenkopi, Arizona

    Science.gov (United States)

    Carruth, Rob; Bills, Donald J.

    2012-01-01

    The Hopi villages of Lower Moencopi and Upper Moenkopi are on the Hopi Indian Reservation south of Tuba City in northern Arizona. These adjacent Hopi villages, located west and north of the confluence of Pasture Canyon Wash and Moenkopi Wash, are dependent on groundwater withdrawals from three wells that penetrate the N aquifer and from two springs that discharge from the N aquifer. The N aquifer is the principal aquifer in this region of northern Arizona and is composed of thick beds of sandstone between less permeable layers of siltstone and mudstone. The fine-grained character of the N aquifer inhibits rapid movement of water and large yields to wells; however, the aquifer is moderately productive at yields generally less than 25 gallons per minute in the study area. In recent years, the water level has declined in the three public-supply wells and the flow from the springs has decreased, causing concern that the current water supply will not be able to accommodate peak demand and allow for residential and economic growth. In addition to the challenge imposed by declining groundwater levels, the water-supply wells and springs are located about 2 miles downgradient from the Tuba City Landfill site where studies are ongoing to determine if uranium and other metals in groundwater beneath the landfill are higher than regional concentrations in the N aquifer. In August 2008, the U.S. Geological Survey, in cooperation with the Hopi Tribe, conducted an aquifer test on well SMW-1, designed to help the Hopi Tribe determine the potential yield and water quality of the N aquifer south of Moenkopi Wash as a possible source of additional water supply. Well SMW-1 was drilled south of Moenkopi Wash to a depth of 760 feet below land surface before being backfilled and cased to about 300 feet. The well penetrates, in descending order, the Navajo Sandstone and the Kayenta Formation, both units of the N aquifer. The pre-test water level in the well was 99.15 feet below land

  9. Groundwater vulnerability mapping in Guadalajara aquifers system (Western Mexico)

    Science.gov (United States)

    Rizo-Decelis, L. David; Marín, Ana I.; Andreo, Bartolomé

    2016-04-01

    Groundwater vulnerability mapping is a practical tool to implement strategies for land-use planning and sustainable socioeconomic development coherent with groundwater protection. The objective of vulnerability mapping is to identify the most vulnerable zones of catchment areas and to provide criteria for protecting the groundwater used for drinking water supply. The delineation of protection zones in fractured aquifers is a challenging task due to the heterogeneity and anisotropy of hydraulic conductivities, which makes difficult prediction of groundwater flow organization and flow velocities. Different methods of intrinsic groundwater vulnerability mapping were applied in the Atemajac-Toluquilla groundwater body, an aquifers system that covers around 1300 km2. The aquifer supplies the 30% of urban water resources of the metropolitan area of Guadalajara (Mexico), where over 4.6 million people reside. Study area is located in a complex neotectonic active volcanic region in the Santiago River Basin (Western Mexico), which influences the aquifer system underneath the city. Previous works have defined the flow dynamics and identified the origin of recharge. In addition, the mixture of fresh groundwater with hydrothermal and polluted waters have been estimated. Two main aquifers compose the multilayer system. The upper aquifer is unconfined and consists of sediments and pyroclastic materials. Recharge of this aquifer comes from rainwater and ascending vertical fluids from the lower aquifer. The lower aquifer consists of fractured basalts of Pliocene age. Formerly, the main water source has been the upper unit, which is a porous and unconsolidated unit, which acts as a semi-isotropic aquifer. Intense groundwater usage has resulted in lowering the water table in the upper aquifer. Therefore, the current groundwater extraction is carried out from the deeper aquifer and underlying bedrock units, where fracture flow predominates. Pollution indicators have been reported in

  10. Conceptual and numerical modeling approach of the Guarani Aquifer System

    Directory of Open Access Journals (Sweden)

    L. Rodríguez

    2013-01-01

    Full Text Available In large aquifers, relevant for their considerable size, regional groundwater modeling remains challenging given geologic complexity and data scarcity in space and time. Yet, it may be conjectured that regional scale groundwater flow models can help in understanding the flow system functioning and the relative magnitude of water budget components, which are important for aquifer management. The Guaraní Aquifer System is the largest transboundary aquifer in South America. It contains an enormous volume of water; however, it is not well known, being difficult to assess the impact of exploitation currently used to supply over 25 million inhabitants. This is a sensitive issue because the aquifer is shared by four countries. Moreover, an integrated groundwater model, and therefore a global water balance, were not available. In this work, a transient regional scale model for the entire aquifer based upon five simplified, equally plausible conceptual models represented by different hydraulic conductivity parametrizations is used to analyze the flow system and water balance components. Combining an increasing number of hydraulic conductivity zones and an appropriate set of boundary conditions, the hypothesis of a continuous sedimentary unit yielded errors within the calibration target in a regional sense. The magnitude of the water budget terms resulted very similar for all parametrizations. Recharge and stream/aquifer fluxes were the dominant components representing, on average, 84.2% of total inflows and 61.4% of total outflows, respectively. However, leakage was small compared to stream discharges of main rivers. For instance, the simulated average leakage for the Uruguay River was 8 m3 s−1 while the observed absolute minimum discharge was 382 m3 s−1. Streams located in heavily pumped regions switched from a gaining condition in early years to a losing condition over time. Water is discharged through

  11. Successful treatment of an MTBE-impacted aquifer using a bioreactor self-colonized by native aquifer bacteria.

    Science.gov (United States)

    Hicks, Kristin A; Schmidt, Radomir; Nickelsen, Michael G; Boyle, Susan L; Baker, Jeffrey M; Tornatore, Paul M; Hristova, Krassimira R; Scow, Kate M

    2014-02-01

    A field-scale fixed bed bioreactor was used to successfully treat an MTBE-contaminated aquifer in North Hollywood, CA without requiring inoculation with introduced bacteria. Native bacteria from the MTBE-impacted aquifer rapidly colonized the bioreactor, entering the bioreactor in the contaminated groundwater pumped from the site, and biodegraded MTBE with greater than 99 % removal efficiency. DNA sequencing of the 16S rRNA gene identified MTBE-degrading bacteria Methylibium petroleiphilum in the bioreactor. Quantitative PCR showed M. petroleiphilum enriched by three orders of magnitude in the bioreactor above densities pre-existing in the groundwater. Because treatment was carried out by indigenous rather than introduced organisms, regulatory approval was obtained for implementation of a full-scale bioreactor to continue treatment of the aquifer. In addition, after confirmation of MTBE removal in the bioreactor to below maximum contaminant limit levels (MCL; MTBE = 5 μg L(-1)), treated water was approved for reinjection back into the aquifer rather than requiring discharge to a water treatment system. This is the first treatment system in California to be approved for reinjection of biologically treated effluent into a drinking water aquifer. This study demonstrated the potential for using native microbial communities already present in the aquifer as an inoculum for ex-situ bioreactors, circumventing the need to establish non-native, non-acclimated and potentially costly inoculants. Understanding and harnessing the metabolic potential of native organisms circumvents some of the issues associated with introducing non-native organisms into drinking water aquifers, and can provide a low-cost and efficient remediation technology that can streamline future bioremediation approval processes.

  12. Microbial community in a geothermal aquifer associated with the subsurface of the Great Artesian Basin, Australia.

    Science.gov (United States)

    Kimura, Hiroyuki; Sugihara, Maki; Yamamoto, Hiroyuki; Patel, Bharat K C; Kato, Kenji; Hanada, Satoshi

    2005-10-01

    To investigate the biomass and phylogenetic diversity of the microbial community inhabiting the deep aquifer of the Great Artesian Basin (GAB), geothermal groundwater gushing out from the aquifer was sampled and analyzed. Microbial cells in the groundwater were stained with acridine orange and directly counted by epifluorescence microscopy. Microbial cells were present at a density of 10(8)-10(9) cells per liter of groundwater. Archaeal and bacterial small-subunit rRNA genes (rDNAs) were amplified by PCR with Archaea- and Bacteria-specific primer sets, and clone libraries were constructed separately. A total of 59 clones were analyzed in archaeal and bacterial 16S rDNA libraries, respectively. The archaeal 16S rDNA clones were divided into nine operated taxonomic units (OTUs) by restriction fragment length polymorphism. These OTUs were closely related to the methanogenic genera Methanospirillum and Methanosaeta, the heterotrophic genus Thermoplasma, or miscellaneous crenarchaeota group. More than one-half of the archaeal clones (59% of total 59 clones) were placed beside phylogenetic clusters of methanogens. The majority of the methanogen-related clones (83%) was closely related to a group of hydrogenotrophic methanogens (genus Methanospirillum). The bacterial OTUs branched into seven phylogenetic clusters related to hydrogen-oxidizing thermophiles in the genera Hydrogenobacter and Hydrogenophilus, a sulfate-reducing thermophile in the genus Thermodesulfovibrio, chemoheterotropic bacteria in the genera Thermus and Aquaspirillum, or the candidate division OP10. Clones closely related to the thermophilic hydrogen-oxidizers in the genera Hydrogenobacter and Hydrogenophilus were dominant in the bacterial clone library (37% of a total of 59 clones). The dominancy of hydrogen-users strongly suggested that H(2) plays an important role as a primary substrate in the microbial ecosystem of this deep geothermal aquifer.

  13. ANALYTICAL SOLUTION OF GROUNDWATER FLUCTUATIONS IN ESTUARINE AQUIFER

    Institute of Scientific and Technical Information of China (English)

    CHEN Jing; ZHOU Zhi-fang; JIA Suo-bao

    2005-01-01

    As a basic factor in the environment of estuary, tidal effects in the coastal aquifer have recently attracted much attention because tidal dynamic also greatly influences the solute transport in the coastal aquifer. Previous studies on tidal dynamic of coastal aquifers have focused on the inland propagation of oceanic tides in the cross-shore direction, a configuration that is essentially one-dimensional. Two-dimensional analytical solutions for groundwater level fluctuation in recent papers are localized in presenting the effect of both oceanic tides and estuarine tides in quadrantal aquifer. A two-dimensional model of groundwater fluctuations in estuarine zone in proposed in this paper. Using complex transform, the two-dimensional flow equation subject to periodic boundary condition is changed into time-independent elliptic problem. Based on Green function method, an analytical solution for groundwater fluctuations in fan-shaped aquifer is derived. The response to of groundwater tidal loading in an estuary and ocean is discussed. The result show that its more extensive application than recent studies.

  14. Optimal Groundwater Development in Coastal Aquifers Near Beihai, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Groundwater resources occur in a multi-aquifer system in the alluvial coastal plain near Beihai, China. The aquifers receive recharge from precipitation, canal and reservoir infiltration, and discharge through subterranean drainage into the sea and through artificial pumping. A quasithree-dimensional finite element model has been used to simulate the spatial and temporal distribution of groundwater levels in the aquifers. Various input parameters were considered in the simulation model. A linear optimization model has been developed for groundwater development within the coastal aquifers. The objective function of the model is to maximize the total groundwater pumpage from the confined aquifer. The control of sea water intrusion is examined by the restriction of the water levels at points along the coast and of the pumping rates in coastal management cells. The response matrix used in the optimization model was generated from the simulation model by forecasting drawdown produced by pumping at a unit impulse discharge. Groundwater development can be primarily optimized by the alteration of the pumping rates of the existing wells.

  15. Fundamental Elements of Geologic C02 Sequestration in Saline Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J W; Nitao, J J; Steefel, C I

    2001-11-19

    Geologic sequestration represents a promising strategy for isolating CO{sub 2} waste streams from the atmosphere. Successful implementation of this approach hinges on our ability to predict the relative effectiveness of subsurface CO{sub 2} migration and sequestration as a function of key target-formation and cap-rock properties, which will enable us to identify optimal sites and evaluate their long-term isolation performance. Quantifying this functional relationship requires a modeling capability that explicitly couples multiphase flow and kinetically controlled geochemical processes. We have developed a unique computational package that meets these criteria, and used it to model CO{sub 2} injection at Statoil's North-Sea Sleipner facility, the world's first saline-aquifer storage site. The package integrates a state-of-the-art reactive transport simulator (NUFT) with supporting geochemical software and databases (SUPCRT92). In our Sleipner study, we have quantified--for the first time--the influence of intra-aquifer shales and aquifer/cap-rock composition on migration/sequestration balance, sequestration partitioning among hydrodynamic, solubility, and mineral trapping mechanisms, and the isolation performance of shale cap rocks. Here, we review the fundamental elements of geologic CO{sub 2} sequestration in saline aquifers as revealed from model XSH of our Sleipner study; this model, unlike CSH and DSH, does not address the complicating (yet advantageous) presence of intra-aquifer shales.

  16. In situ arsenic removal in an alkaline clastic aquifer

    Science.gov (United States)

    Welch, A.H.; Stollenwerk, K.G.; Paul, A.P.; Maurer, D.K.; Halford, K.J.

    2008-01-01

    In situ removal of As from ground water used for water supply has been accomplished elsewhere in circum-neutral ground water containing high dissolved Fe(II) concentrations. The objective of this study was to evaluate in situ As ground-water treatment approaches in alkaline ground-water (pH > 8) that contains low dissolved Fe (water in the two aquifers studied are similar except for the inorganic As species. Although total inorganic As concentrations were similar, one aquifer has dominantly aqueous As(III) and the other has mostly As(V). Dissolved O2, Fe(II), and HCl were added to water and injected into the two aquifers to form Fe-oxide and lower the pH to remove As. Cycles of injection and withdrawal involved varying Fe(II) concentrations in the injectate. The As concentrations in water withdrawn from the two aquifers were as low as 1 and 6 ??g/L, with greater As removal from the aquifer containing As(V). However, Fe and Mn concentrations increased to levels greater than US drinking water standards during some of the withdrawal periods. A balance between As removal and maintenance of low Fe and Mn concentrations may be a design consideration if this approach is used for public-supply systems. The ability to lower As concentrations in situ in high-pH ground water should have broad applicability because similar high-As ground water is present in many parts of the world. ?? 2008.

  17. Factors influencing the stream-aquifer flow exchange coefficient.

    Science.gov (United States)

    Morel-Seytoux, Hubert J; Mehl, Steffen; Morgado, Kyle

    2014-01-01

    Knowledge of river gain from or loss to a hydraulically connected water table aquifer is crucial in issues of water rights and also when attempting to optimize conjunctive use of surface and ground waters. Typically in groundwater models this exchange flow is related to a difference in head between the river and some point in the aquifer, through a "coefficient." This coefficient has been defined differently as well as the location for the head in the aquifer. This paper proposes a new coefficient, analytically derived, and a specific location for the point where the aquifer head is used in the difference. The dimensionless part of the coefficient is referred to as the SAFE (stream-aquifer flow exchange) dimensionless conductance. The paper investigates the factors that influence the value of this new conductance. Among these factors are (1) the wetted perimeter of the cross-section, (2) the degree of penetration of the cross-section, and (3) the shape of the cross-section. The study shows that these factors just listed are indeed ordered in their respective level of importance. In addition the study verifies that the analytical correct value of the coefficient is matched by finite difference simulation only if the grid system is sufficiently fine. Thus the use of the analytical value of the coefficient is an accurate and efficient alternative to ad hoc estimates for the coefficient typically used in finite difference and finite element methods. © 2013, National Ground Water Association.

  18. FEMA: a Finite Element Model of Material Transport through Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, G.T.; Huff, D.D.

    1985-01-01

    This report documents the construction, verification, and demonstration of a Finite Element Model of Material Transport through Aquifers (FEMA). The particular features of FEMA are its versatility and flexibility to deal with as many real-world problems as possible. Mechanisms included in FEMA are: carrier fluid advection, hydrodynamic dispersion and molecular diffusion, radioactive decay, sorption, source/sinks, and degradation due to biological, chemical as well as physical processes. Three optional sorption models are embodied in FEMA. These are linear isotherm and Freundlich and Langmuir nonlinear isotherms. Point as well as distributed source/sinks are included to represent artificial injection/withdrawals and natural infiltration of precipitation. All source/sinks can be transient or steady state. Prescribed concentration on the Dirichlet boundary, given gradient on the Neumann boundary segment, and flux at each Cauchy boundary segment can vary independently of each other. The aquifer may consist of as many formations as desired. Either completely confined or completely unconfined or partially confined and partially unconfined aquifers can be dealt with effectively. FEMA also includes transient leakage to or from the aquifer of interest through confining beds from or to aquifers lying below and/or above.

  19. Thickness of the surficial aquifer, Delmarva Peninsula, Maryland and Delaware

    Science.gov (United States)

    Denver, Judith; Nardi, Mark R.

    2017-01-01

    A digital map of the thickness of the surficial unconfined aquifer, including from the land surface and unsaturated zone to the bottom of sediments of geologic units identified as part of the surficial aquifer, was produced to improve understanding of the hydrologic system in the Maryland and Delaware portions of the Delmarva Peninsula. The map is intended to be used in conjunction with other environmental coverages (such land use, wetlands, and soil characteristics) to provide a subsurface hydrogeologic component to studies of nitrate transport that have historically relied on maps of surficial features. It could also be used to study the transport of other water soluble chemicals. The map was made using the best currently available data, which was of varying scales. It was created by overlaying a high resolution land surface and bathymetry digital elevation model (DEM) on a digital representation of the base of the surficial aquifer, part of hydrogeologic framework, as defined by Andreasen and others (2013). Thickness was calculated as the difference between the top of land surface and the bottom of the surficial aquifer sediments, which include sediments from geologic formations of late-Miocene through Quaternary age. Geologic formations with predominantly sandy surficial sediments that comprise the surficial aquifer on the Delmarva Peninsula include the Parsonsburg Sand, Sinepuxent Formation (Fm.), and parts of the Omar Fm. north of Indian River Bay in Delaware, the Columbia Fm., Beaverdam Fm., and Pennsauken Fm. (Ator and others 2005; Owens and Denney, 1986; Mixon, 1985; Bachman and Wilson, 1984). Formations with mixed texture and sandy stratigraphy including the Scotts Corner Fm. and Lynch Heights Fm. in Delaware are also considered part of the surficial aquifer (Ramsey, 1997). Subcropping aquifers and confining beds underlie the surficial aquifer throughout the Peninsula and may increase or limit its thickness, respectively (Andreasen and others, 2013

  20. Wave-Induced Groundwater Flows in a Freshwater Beach Aquifer

    Science.gov (United States)

    Malott, S. S.; Robinson, C. E.; O'Carroll, D. M.

    2014-12-01

    Wave-induced recirculation across the sediment-water interface can impact the transport of pollutants through a beach aquifer and their ultimate flux into coastal waters. The fate of nutrients (e.g. from septic and agricultural sources) and fecal indicator bacteria (e.g. E. coil) near the sediment-water interface are of particular concern as these pollutants often lead to degradation of recreational water quality and nearshore ecosystems. This paper presents detailed field measurements of groundwater flows in a freshwater beach aquifer on Lake Huron over periods of intensified wave conditions. Quantifying wave-driven processes in a freshwater beach aquifer enables wave effects to be studied in isolation from density and tidal effects that complicate groundwater flows in marine beaches. Water exchange across the sediment-water interface and groundwater flow patterns were measured using groundwater wells, arrays of vertically nested pressure transducers and manometers. Results show that wave action induces rapid infiltration/exfiltration across the sediment-water interface and a larger recirculation cell through the beach aquifer. Field data is used to validate a numerical groundwater model of wave-induced groundwater flows. While prior studies have simulated the effects of waves on beach groundwater flows, this study is the first attempt to validate these sophisticated modeling approaches. Finally, field data illustrating the impact of wave-induced groundwater flows on nutrient and bacteria fate and transport in beach aquifers will also be presented.

  1. Base of principal aquifer for parts of the North Platte, South Platte, and Twin Platte Natural Resources Districts, western Nebraska

    Science.gov (United States)

    Hobza, Christopher M.; Abraham, Jared D.; Cannia, James C.; Johnson, Michaela R.; Sibray, Steven S.

    2014-01-01

    coordinates. The process of interpretation involved manually picking locations (base-of-aquifer elevations) on the displayed airborne electromagnetic-derived resistivity profile by the project geophysicist, hydrologist, and geologist. These locations, or picks, of the base-of-aquifer elevation (typically the top of the Brule Formation of the White River Group) were then stored in a georeferenced database. The pick was made by comparing the inverted airborne electromagnetic-derived resistivity profile to the lithologic descriptions and borehole geophysical logs from nearby test holes. The database of interpretive picks of the base-of-aquifer elevation was used to create primary input for interpolating the new base-of-aquifer contours. The automatically generated contours were manually adjusted based on the interpreted location of paleovalleys eroded into the base-of-aquifer surface and associated bedrock highs, many of which were unmapped before this study. When contours are overlain by the water-table surface, the saturated thickness of the aquifer can be computed, which allows an estimate of total water in storage. The contours of the base-of-aquifer surface presented in this report may be used as the lower boundary layer in existing and future groundwater-flow models. The integration of geophysical data into the contouring process facilitated a more continuous and spatially comprehensive view of the hydrogeologic framework.

  2. Aquifer Properties in Hepokangas, Northern Finland

    Science.gov (United States)

    Pihlaja, M. Sc.

    2012-04-01

    Hepokangas study area is located in northern Finland, app. 60 km north-east of the city of Oulu. It consists of an esker ridge which ranges in elevation from 95 to 105 m.a.s.l. Consequently, all Quaternary deposits in the area have been influenced by erosional and depositional processes during two Baltic Sea stages (Ancylus Lake and Littorina Sea). Therefore, raised beaches are found on the esker slopes and fine grained sediments on the lowlands. The studied aquifer, the Hepokangas esker is part of an discontinuous chain of eskers which, in total, is about 100 km long and is elongated from north-west to south-east. The direction indicates that the esker was deposited by the melt waters during the latest phase of Weichselian glaciation. The primary part of the esker is located in the western segment of the area and a delta-like expansion of an esker is in the eastern part of the study area . Level of the ground water table (GWT) was measured at 14 ground water pipes which were located in varying parts of the Hepokangas formation. Ground penetrating radar (GPR) surveys were conducted on the primary part of the esker in order to determine internal structures and estimate permeability of the formation. Ground water flow directions were interpreted based on these measurements. The GWT varies from 91.91 to 97.98 m.a.s.l. Since the Hepokangas formation is surrounded by mires the height of the GWT decreased towards them. There was a water pumping station on the primary part of the formation, but no clear effect to the GWT could be seen to be caused by that. From the GPR results, some locations of the coarse grain sediments with high permeability were found.

  3. A generalized solution for groundwater head fluctuation in a tidal leaky aquifer system

    Indian Academy of Sciences (India)

    Mo-Hsiung Chuang; Hund-Der Yeh

    2011-12-01

    A new analytical solution is developed for describing groundwater level fluctuations in a coupled leaky confined aquifer system which consists of an unconfined aquifer, confined aquifer, and an aquitard in between. The aquifer system has a tidal boundary at the seashore, a no flow boundary at remote inland side, and a confined aquifer extending under the sea and terminated with an outlet-capping. This new solution has shown to be a generalisation of most existing analytical solutions for a tidal aquifer system which includes single confined and leaky confined aquifers. In addition, the solution is used to explore the influences of the dimensionless leakance of the outlet-capping, the dimensionless hydraulic diffusivities, and the leakages of the inland and offshore aquitards on the head responses in the leaky confined aquifer.

  4. Managed Aquifer Recharge: from Local Research and Experiences to Regional Aquifer Storage and Recovery

    Science.gov (United States)

    Hendriks, D.; Faneca, M.; Oude Essink, G.; van Baaren, E.; Stuurman, R.; Delsman, J. R.; van Kempen, C.; de Louw, P.

    2016-12-01

    Many areas in the world experience periodic water shortages due to meteorological drought, salt water intrusion or over-exploitation of the water resources. Recently, it was established that the depletion of aquifers in many areas of the world is in an advanced state (Gleeson et al, 2012). This poses enormous challenges as 2.5 billion people and many companies depend on groundwater now and in the future (UN, 2015; ESG, 2016). A solution to increase robustness of water systems and prevent water shortage is subsurface storage of water during wet periods using Managed Aquifer Research (MAR). In addition to mitigation of water shortage, MAR can also reduce the occurrence and degree of flooding. Here, we present an overview of Deltares MAR expertise and available tools for up-scaling MAR. Deltares has experience with both research and implementation of MAR in different parts of the world under various hydro(geo)logical, climatic and socio-economic conditions. Various MAR techniques were assessed/tested in coastal areas of the Netherlands, Spain, New York, New Orleans and in Bangladesh. In some of these areas specific groundwater shortage related issues occur, such as salt water intrusion or subsidence. In Singapore, monitoring campaigns and modeling were done to design MAR by infiltration of water in over-exploited aquifers. In Abu Dhabi, geophysical methods were used to detect the optimal conditions for MAR systems. To effectively increase the robustness of groundwater systems up-scaling of MAR is required. For this purpose, Deltares developed tools that provide insight in the potential demand, possibilities and effectiveness of MAR at larger scales. The Quick scan tool for Fresh Groundwater Buffering provides insight on regional to national scale and is based on GIS-information of water demand, water resources, and subsurface properties. This quick scan tool has been applied for Mozambique, Kenya, India and Bangladesh. The Fresh Water Optimizer assesses the

  5. Geochemical and isotopic composition of ground water with emphasis on sources of sulfate in the upper Floridan Aquifer and intermediate aquifer system in southwest Florida

    Science.gov (United States)

    Sacks, Laura A.; Tihansky, Ann B.

    1996-01-01

    In southwest Florida, sulfate concentrations in water from the Upper Floridan aquifer and overlying intermediate aquifer system are commonly above 250 milligrams per liter (the drinking water standard), particularly in coastal areas. Possible sources of sulfate include dissolution of gypsum from the deeper part of the Upper Floridan aquifer or the middle confining unit, saltwater in the aquifer, and saline waters from the middle confining unit and Lower Floridan aquifer. The sources of sulfate and geochemical processes controlling ground-water composition were evaluated for the Peace and Myakka River Basins and adjacent coastal areas of southwest Florida. Samples were collected from 63 wells and a saline spring, including wells finished at different depth intervals of the Upper Floridan aquifer and intermediate aquifer system at about 25 locations. Sampling focused along three ground-water flow paths (selected based on a predevelopment potentiometric-surface map). Ground water was analyzed for major ions, selected trace constituents, dissolved organic carbon, and stable isotopes (delta deuterium, oxygen-18, carbon-13 of inorganic carbon, and sulfur-34 of sulfate and sulfide); the ratio of strontium-87 to strontium-86 was analyzed for waters along one of the flow paths. Chemical and isotopic data indicate that dedolomitization reactions (gypsum and dolomite dissolution and calcite precipitation) control the chemical composition of water in the Upper Floridan aquifer in inland areas. This is confirmed by mass-balance modeling between wells in the shallowest interval in the aquifer along the flow paths. However, gypsum occurs deeper in the aquifer than these wells. Upwelling of sulfate-rich water that previously dissolved gypsum in deeper parts of the aquifer is a more likely source of sulfate than gypsum dissolution in shallow parts of the aquifer. This deep ground water moves to shallower zones in the aquifer discharge area. Saltwater from the Upper Floridan aquifer

  6. Modeling CO2 Sequestration in Saline Aquifer and Depleted Oil Reservoirs to Evaluate Regional CO2 Sequestration Potential of Ozark Plateau Aquifer System, South-Central Kansas

    Science.gov (United States)

    Watney, W. L.; Rush, J.

    2011-12-01

    The Paleozoic-age Ozark Plateau Aquifer System (OPAS) in southern Kansas consists of a thick (>450 m) and deeply buried (>1 km) succession of Cambro-Ordovician Arbuckle Group strata (dolomite) overlain by Lower Ordovician to Lower Carboniferous-age carbonate, chert, and shale. The Arbuckle Group is a thick widespread saline aquifer in southern Kansas. A 500 meter core of the OPAS interval and immediate overlying Pennsylvanian shale caprock were cored in early 2011 in the BEREXCO Wellington KGS #1-32 well in Wellington Field, a nearly depleted oil field in Sumner County, in south-central Kansas. An exhaustive set of modern logs were run in the KGS #1-32 well including chemical, microresistivity imaging, dipole sonic, nuclear magnetic resonance, and standard porosity and resistivity wireline logs. In addition, routine and special core analyses provide vital means to calibrate these logs. Core also provide vital chemical analyses and rock samples to run flow experiments, including in situ conditions, to establish reaction kinetics of rock and connate brines with CO2. Core and logs also provide the means to calibrate a 26 km2 multicomponent 3D seismic survey that was acquired in Wellington Field in 2010. Studies of four oil fields, also part of this project, are underway in southwestern Kansas to provide additional calibration points for the western part of the regional study that covers 65,000 km2 where CO2 sequestration capacity will be measured. Several hundred deep wells have been identified to serve as type wells in the regional study area. Well logs and sample descriptions are being digitized, correlated, and mapped to define distribution of aquifers, oil reservoirs, and caprocks. Drill stem test data have been analyzed for deep wells to establish that the Arbuckle is an open aquifer connected to surface exposures 100s of km to east in central Missouri. Over 500 km2 of 3D seismic have been donated by industrial partners to aid in understanding fault and fracture

  7. Karst Aquifer Recharge: Comments on Somaratne, N. Characteristics of Point Recharge in Karst Aquifers. Water 2014, 6, 2782–2807

    Directory of Open Access Journals (Sweden)

    Adrian D. Werner

    2014-11-01

    Full Text Available The article “Characteristics of Point Recharge in Karst Aquifers, Water 6: 2782–2807” by N. Somaratne evaluates various recharge estimation techniques applied to four limestone aquifers in South Australia. Somaratne [1] concludes that methods based on watertable fluctuations, groundwater modelling and water budgets are independent of recharge processes, and are therefore superior to the chloride mass balance (CMB approach for karst aquifers. The current comment offers alternative interpretations from existing field measurements and previous literature, in particular for the Uley South aquifer, which is the focus of much of the article by Somaratne [1]. Conclusions regarding this system are revised, partly to account for the misrepresentation of previous studies. The aeolianite sediments of Uley South are mostly unconsolidated or poorly consolidated, and dissolution features in the calcrete capping provide point infiltration into a predominantly unconsolidated vadose zone, whereas Somaratne’s [1] findings require that the system comprises well-developed conduits in otherwise low-conductivity limestone. Somaratne’s [1] assertion that the basic premise of CMB is violated in Uley South is disputable, given strong evidence of relatively well-mixed groundwater arising from mostly diffuse recharge. The characterization of karst aquifer recharge should continue to rely on multiple techniques, including environmental tracers such as chloride.

  8. Hydrologic analysis of data for the Lost Lake Aquifer Zone of the Steel Pond Aquifer at recovery well RWM-16

    Energy Technology Data Exchange (ETDEWEB)

    Wells, D.G.; Cook, J.W.; Hiergesell, R.A.

    1993-04-01

    This report presents the results of an analysis of data obtained from a large-scale, multiple-well aquifer test of the sandy unit referred to as the Lost Lake Aquifer Zone of the Steed Pond Aquifer in an area just south of the A and M Areas. Pumping was conducted at recovery well RWM-16, which is located near the MSB-40 well cluster, approximately 4000 feet south of the M-Area Basin. RWM-16 is located in the lower left portion of Figure 1, which also illustrates the general relationship of the testing site to the A and M Areas and other monitor wells. The data generated from testing RWM-16 was used to calculate estimates of transmissivity and storage for the aquifer system within which RWM-16 is screened. These parameters are related to hydraulic conductivity and storativity of the aquifer system by the vertical thickness of the unit. The leakage coefficient for the overlying confining unit is also estimated. This information is needed to refine conceptual understanding of the groundwater flow system beneath the A and M Areas. The refined conceptual model will more adequately describe the pattern of groundwater flow, and will contribute to updating the {open_quotes}Zone of Capture{close_quotes} model that has been used in the initial phases of designing a groundwater remediation system in the A and M Areas.

  9. Water quality management of aquifer recharge using advanced tools.

    Science.gov (United States)

    Lazarova, Valentina; Emsellem, Yves; Paille, Julie; Glucina, Karl; Gislette, Philippe

    2011-01-01

    Managed aquifer recharge (MAR) with recycled water or other alternative resources is one of the most rapidly growing techniques that is viewed as a necessity in water-short areas. In order to better control health and environmental effects of MAR, this paper presents two case studies demonstrating how to improve water quality, enable reliable tracing of injected water and better control and manage MAR operation in the case of indirect and direct aquifer recharge. Two water quality management strategies are illustrated on two full-scale case studies, including the results of the combination of non conventional and advanced technologies for water quality improvement, comprehensive sampling and monitoring programs including emerging pollutants, tracer studies using boron isotopes and integrative aquifer 3D GIS hydraulic and hydrodispersive modelling.

  10. Aquifer storage and recovery: recent hydrogeological advances and system performance.

    Science.gov (United States)

    Maliva, Robert G; Guo, Weixing; Missimer, Thomas M

    2006-12-01

    Aquifer storage and recovery (ASR) is part of the solution to the global problem of managing water resources to meet existing and future freshwater demands. However, the metaphoric "ASR bubble" has been burst with the realization that ASR systems are more physically and chemically complex than the general conceptualization. Aquifer heterogeneity and fluid-rock interactions can greatly affect ASR system performance. The results of modeling studies and field experiences indicate that more sophisticated data collection and solute-transport modeling are required to predict how stored water will migrate in heterogeneous aquifers and how fluid-rock interactions will affect the quality of stored water. It has been well-demonstrated, by historic experience, that ASR systems can provide very large volumes of storage at a lesser cost than other options. The challenges moving forward are to improve the success rate of ASR systems, optimize system performance, and set expectations appropriately.

  11. Copper and zinc distribution coefficients for sandy aquifer materials

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Boddum, J. K.

    2000-01-01

    ; Zn: 6±22,800 l/kg) and correlating them to the characteristics of the aquifer material (particle size distribution, organic C content, surface area, pH) revealed good correlation with pH in the range 5.3± 8.9 (Cu: r 2=0.72; Zn: r 2=0.94). Including any other of the measured aquifer characteristics...... improved the correlation only a few percent. The results indicate that the mobility of Cu and Zn in sandy aquifers, as re¯ected in the measured Kd values, is very restricted at pH values above 6, since the relative migration velocity is less than 1%. However, at lower pH values, Zn seems to become mobile...

  12. Physical model simulations of seawater intrusion in unconfined aquifer

    Directory of Open Access Journals (Sweden)

    Tanapol Sriapai

    2012-12-01

    Full Text Available The objective of this study is to simulate the seawater intrusion into unconfined aquifer near shoreline and to assessthe effectiveness of its controlling methods by using scaled-down physical models. The intrusion controlled methods studiedhere include fresh water injection, saltwater extraction, and subsurface barrier. The results indicate that under natural dynamicequilibrium between the recharge of fresh water and the intrusion well agree with the Ghyben-Herzberg mathematical solution.Fresh water pumping from the aquifer notably move the fresh-salt water interface toward the pumping well, depending on thepumping rates and the head differences (h between the aquifer recharge and the salt water level. The fresh water injectionmethod is more favorable than the salt water extraction and subsurface barrier method. The fresh water injection rate of about10% of the usage rate can effectively push the interface toward the shoreline, and keeping the pumping well free of salinity.

  13. Numerical Modeling of Natural and Enhanced Denitrification Processes in Aquifers

    Science.gov (United States)

    Kinzelbach, Wolfgang; SchäFer, Wolfgang; Herzer, JöRg

    1991-06-01

    Nitrate modeling in the groundwater environment must incorporate microbial denitrification as the major process of nitrate elimination. A multispecies transport model is presented which describes the interaction of oxygen, nitrate, organic carbon, and bacteria. Three phases (mobile pore water, biophase, and aquifer material) are taken into account. The model is applied to a natural aquifer situation as well as to an in situ remediation case where nitrate is employed as an oxidant. In the natural aquifer it is shown that the release of organic carbon from the matrix is the controlling factor for denitrification. In the remediation case, on the other hand, the data suggest that diffusion limitation of the nutrient supply to the biophase controls bacterial growth.

  14. Aquifers productivity in the Pan-African context

    Indian Academy of Sciences (India)

    Aretouyap Zakari; Nouayou Robert; Njandjock Nouck Philippe; Asfahani Jamal

    2015-04-01

    In this study, 50 Vertical Electrical Soundings (VES) were carried out in the region, including 14 near existing boreholes for comparison. Aquifer parameters of hydraulic conductivity and transmissivity were obtained by analyzing pumping test data from existing boreholes. An empirical relationship between hydraulic conductivity (K) obtained from pumping test and both resistivity and thickness of the Pan-African aquifer has been established for these boreholes in order to calculate the geophysical hydraulic conductivity. The geoelectrical interpretation shows that almost all aquifers are made of the fractured portion of the granitic bedrock located at a depth ranging between 7 and 84 m. The hydraulic conductivity varies between 0.012 and 1.677 m/day, the resistivity between 3 and 825 m, the thickness between 1 and 101 m, the transmissivity between 0.46 and 46.02 m2/day, the product K between 2.1 × 10−4 and 4.2 × 10−4.

  15. Field observations, preliminary model analysis, and aquifer thermal efficiency

    Science.gov (United States)

    Miller, R.T.; Delin, G.N.

    1993-01-01

    In May 1980, the University of Minnesota began a project to evaluate the feasibility of storing heated (150 degrees Celsius (°C) water in the deep (180 to 240 meters (m)) Franconia-Ironton-Galesville aquifer and later recovering it for space heating. The Aquifer Thermal-Energy Storage (ATES) system was a doublet-well design in which the injection and withdrawal wells were spaced approximately 250 m apart. High-temperature water from the university's steam-generation facilities supplied heat for injection. Water was pumped from one of the wells through a heat exchanger, where heat was added or removed. Water then was injected back into the aquifer through the other well. The experimental plan for testing the ATES system consisted of a series of short-term hot-water injection, storage, and withdrawal cycles. Each cycle was 24 days long, and each injection, storage, and withdrawal step of the cycle was 8 days.

  16. Identifying sources and controlling factors of arsenic release in saline groundwater aquifers

    OpenAIRE

    Liu, C. -W.; Lu, K.-L.; Kao, Y.-H.; Wang, C.-J.; Maji, S.-K.; Lee, J.-F.

    2014-01-01

    An integrated hydrogeochemical study was carried out to realize the occurrence of arsenic (As) in a saline aquifer. Saline groundwater was mostly concentrated in the uppermost aquifer, and non-saline water was in the lower aquifer in the study area. High As concentrations were found in both the uppermost and lower aquifers. No correlation among salinity, well depth and As concentration was observed. Various forms of Fe oxyhydroxides were identified in the magnetic fractions,...

  17. Large fractions of CO2-fixing microorganisms in pristine limestone aquifers appear to be involved in the oxidation of reduced sulfur and nitrogen compounds

    Science.gov (United States)

    Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe; Küsel, Kirsten

    2015-01-01

    The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 103 to 6 × 106 genes liter−1 over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricellaand Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds.

  18. Large Fractions of CO2-Fixing Microorganisms in Pristine Limestone Aquifers Appear To Be Involved in the Oxidation of Reduced Sulfur and Nitrogen Compounds

    Science.gov (United States)

    Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe

    2015-01-01

    The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 103 to 6 × 106 genes liter−1 over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricella and Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds. PMID:25616797

  19. On the aquitard-aquifer interface flow and the drawdown sensitivity with a partially penetrating pumping well in an anisotropic leaky confined aquifer

    Science.gov (United States)

    Feng, Qinggao; Zhan, Hongbin

    2015-02-01

    A mathematical model for describing groundwater flow to a partially penetrating pumping well of a finite diameter in an anisotropic leaky confined aquifer is developed. The model accounts for the jointed effects of aquitard storage, aquifer anisotropy, and wellbore storage by treating the aquitard leakage as a boundary condition at the aquitard-aquifer interface rather than a volumetric source/sink term in the governing equation, which has never developed before. A new semi-analytical solution for the model is obtained by the Laplace transform in conjunction with separation of variables. Specific attention was paid on the flow across the aquitard-aquifer interface, which is of concern if aquitard and aquifer have different pore water chemistry. Moreover, Laplace-domain and steady-state solutions are obtained to calculate the rate and volume of (total) leakage through the aquitard-aquifer interface due to pump in a partially penetrating well, which is also useful for engineers to manager water resources. The sensitivity analyses for the drawdown illustrate that the drawdown is most sensitive to the well partial penetration. It is apparently sensitive to the aquifer anisotropic ratio over the entire time of pumping. It is moderately sensitive to the aquitard/aquifer specific storage ratio at the intermediate times only. It is moderately sensitive to the aquitard/aquifer vertical hydraulic conductivity ratio and the aquitard/aquifer thickness ratio with the identical influence at late times.

  20. Geochemical processes during five years of aquifer storage recovery.

    Science.gov (United States)

    Herczeg, Andrew L; Rattray, Karen J; Dillon, Peter J; Pavelic, Paul; Barry, Karen E

    2004-01-01

    A key factor in the long-term viability of aquifer storage recovery (ASR) is the extent of mineral solution interaction between two dissimilar water types and consequent impact on water quality and aquifer stability. We collected geochemical and isotopic data from three observation wells located 25, 65, and 325 m from an injection well at an experimental ASR site located in a karstic, confined carbonate aquifer in South Australia. The experiment involved five major injection cycles of a total of 2.5 x 10(5) m3 of storm water (total dissolved solids [TDS] approximately 150 mg/L) into the brackish (TDS approximately 2400 mg/L) aquifer. Approximately 60% of the mixture was pumped out during the fifth year of the experiment. The major effect on water quality within a 25 m radius of the injection well following injection of storm water was carbonate dissolution (35 +/- 6 g of CaCO3 dissolved/m3 of aquifer) and sulfide mineral oxidation (50 +/- 10 g as FeS2/m3 after one injection). < 0.005% of the total aquifer carbonate matrix was dissolved during each injection event, and approximately 0.2% of the total reduced sulfur. Increasing amounts of ambient ground water was entrained into the injected mixture during each of the storage periods. High 14C(DIC) activities and slightly more negative delta13C(DIC) values measured immediately after injection events show that substantial CO2(aq) is produced by oxidation of organic matter associated with injectant. There were no detectable geochemical reactions while pumping during the recovery phase in the fifth year of the experiment.

  1. Mobilization and micellar solubilization of NAPL contaminants in aquifer rocks

    Science.gov (United States)

    Javanbakht, Gina; Goual, Lamia

    2016-02-01

    Surfactant-enhanced aquifer remediation is often performed to overcome the capillary forces that keep residual NAPL phases trapped within contaminated aquifers. The surfactant selection and displacement mechanism usually depend on the nature of NAPL constituents. For example, micellar solubilization is often used to cleanup DNAPLs from aquifers whereas mobilization is desirable in aquifers contaminated by LNAPLs. Although the majority of crude oils are LNAPLs, they often contain heavy organic macromolecules such as asphaltenes that are classified as DNAPLs. Asphaltenes contain surface-active components that tend to adsorb on rocks, altering their wettability. Previous studies revealed that surfactants that formed Winsor type III microemulsions could promote both mobilization and solubilization. However the extent by which these two mechanisms occur is still unclear, particularly in oil-contaminated aquifers. In this study we investigated the remediation of oil-contaminated aquifers using an environmentally friendly surfactant such as n-Dodecyl β-D-maltoside. Focus was given on asphaltenes to better understand the mechanisms of surfactant cleanup. Through phase behavior, spontaneous imbibition, dynamic interfacial tension and contact angle measurements, we showed that microemulsions formed by this surfactant are able to mobilize bulk NAPL (containing 9 wt.% asphaltenes) in the porous rock and solubilize DNAPL (i.e., 4-6 wt.% adsorbed asphaltenes) from the rock surface. Spontaneous imbibition tests, in particular, indicated that the ratio of mobilized to solubilized NAPL is about 6:1. Furthermore, aging the cores in NAPL beyond 3 days allowed for more NAPL to be trapped in the large pores of the rock but did not alter the amount of asphaltenes adsorbed on the mineral surface.

  2. Localized sulfate-reducing zones in a coastal plain aquifer

    Science.gov (United States)

    Brown, C.J.; Coates, J.D.; Schoonen, M.A.A.

    1999-01-01

    High concentrations of dissolved iron in ground water of coastal plain or alluvial aquifers contribute to the biofouling of public supply wells for which treatment and remediation is costly. Many of these aquifers, however, contain zones in which microbial sulfate reduction and the associated precipitation of iron-sulfide minerals decreases iron mobility. The principal water-bearing aquifer (Magothy Aquifer of Cretaceous age) in Suffolk County, New York, contains localized sulfate-reducing zones in and near lignite deposits, which generally are associated with clay lenses. Microbial analyses of core samples amended with [14C]-acetate indicate that microbial sulfate reduction is the predominant terminal-electron-accepting process (TEAP) in poorly permeable, lignite-rich sediments at shallow depths and near the ground water divide. The sulfate-reducing zones are characterized by abundant lignite and iron-sulfide minerals, low concentrations of Fe(III) oxyhydroxides, and by proximity to clay lenses that contain pore water with relatively high concentrations of sulfate and dissolved organic carbon. The low permeability of these zones and, hence, the long residence time of ground water within them, permit the preservation and (or) allow the formation of iron-sulfide minerals, including pyrite and marcasite. Both sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB) are present beneath and beyond the shallow sulfate-reducing zones. A unique Fe(III)-reducing organism, MD-612, was found in core sediments from a depth of 187 m near the southern shore of Long Island. The distribution of poorly permeable, lignite-rich, sulfate-reducing zones with decreased iron concentration is varied within the principal aquifer and accounts for the observed distribution of dissolved sulfate, iron, and iron sulfides in the aquifer. Locating such zones for the placement of production wells would be difficult, however, because these zones are of limited aerial extent.

  3. A method for quantifying bioavailable organic carbon in aquifer sediments

    Science.gov (United States)

    Rectanus, H.V.; Widdowson, M.; Novak, J.; Chapelle, F.

    2005-01-01

    The fact that naturally occurring microorganisms can biodegrade PCE and TCE allows the use of monitored natural attenuation (MNA) as a remediation strategy at chlorinated solvent-contaminated sites. Research at numerous chlorinated solvent sites indicates an active dechlorinating microbial population coupled with an ample supply of organic carbon are conditions needed to sustain reductive dechlorination. A series of extraction experiments was used to compare the ability of the different extractants to remove organic carbon from aquifer sediments. The different extractants included pyrophosphate, sodium hydroxide, and polished water. Pyrophosphate served as a mild extractant that minimally alters the organic structure of the extracted material. Three concentrations (0.1, 0.5, and 1%) of pyrophosphate extracted 18.8, 24.9, and 30.8% of sediment organic carbon, respectively. Under alkali conditions (0.5 N NaOH), which provided the harshest extractant, 30.7% of the sediment organic carbon was recovered. Amorphous organic carbon, measured by potassium persulfate oxidization, consisted of 44.6% of the sediment organic carbon and served as a baseline control for maximum carbon removal. Conversely, highly purified water provided a minimal extraction control and extracted 5.7% of the sediment organic carbon. The removal of organic carbon was quantified by aqueous TOC in the extract and residual sediment organic carbon content. Characterization of the organic carbon extracts by compositional analysis prior and after exposure to the mixed culture might indicate the type organic carbon and functional groups used and/or generated by the organisms. This is an abstract of a paper presented at the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

  4. Microbial Response to Carbon Dioxide Injection in a Shallow Aquifer

    Science.gov (United States)

    Rook, A.; Faehndrich, D.; O'Mullan, G.; Mailloux, B.; Matter, J.; Stute, M.; Goldberg, D.

    2007-12-01

    Extensive research is underway to investigate the geophysical and geochemical dynamics of subsurface carbon sequestration, but there has been only theoretical consideration of the microbial response. Microbial dynamics are capable of altering the range and rates of geochemical reactions in the subsurface. The goal of this field experiment is to link geochemical changes due to CO2 injection to alterations in the microbial community and to provide an initial characterization of the microbial response. A seven week push-pull experiment was conducted at the Lamont-Doherty Earth Observatory Test Well. 200L of groundwater was extracted, bubbled with carbon dioxide, augmented with a bromide tracer, and injected to 230m depth below ground surface. The hydraulically isolated injection zone marked the contact area between dolerite sill and sedimentary rock. Samples were taken on a weekly basis. Geochemically, a drop in pH from 9.4 to 4.5 at injection was coupled with a release of Fe2+ from the formation. As neutralization and mixing caused pH to return toward background levels, Fe2+ concentrations decreased. The aquifer remained anoxic throughout the experiment. DNA was successfully extracted and the gene encoding 16S ribosomal RNA was amplified from all samples with the exception of the injection fluid. Sequencing from clone libraries and tRFLP analyses were used to characterize microbial dynamics during the seven week study. Whereas the number of microbial groups detected remained relatively constant over the course of the experiment, changes were observed in both the dominant microbes phylogenetic identity and relative abundance. Methane concentrations increased from background levels (below 50 nM) to 4.2 nM after injection, but initial attempts to amplify archaeal and methanogen-specific genes were unsuccessful, bringing into question the presence of a significant methanogenic population. These results confirm that there is a microbial response to carbon dioxide

  5. Using pressure and volumetric approaches to estimate CO2 storage capacity in deep saline aquifers

    NARCIS (Netherlands)

    Thibeau, S.; Bachu, S.; Birkholzer, J.; Holloway, S.; Neele, F.P.; Zou, Q.

    2014-01-01

    Various approaches are used to evaluate the capacity of saline aquifers to store CO2, resulting in a wide range of capacity estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches. We present four full-scale aquifer cases, where C

  6. River bank geomorphology controls groundwater arsenic concentrations in aquifers adjacent to the Red River, Hanoi Vietnam

    Science.gov (United States)

    Stahl, Mason O.; Harvey, Charles F.; van Geen, Alexander; Sun, Jing; Thi Kim Trang, Pham; Mai Lan, Vi; Mai Phuong, Thao; Hung Viet, Pham; Bostick, Benjamin C.

    2016-08-01

    Many aquifers that are highly contaminated by arsenic in South and Southeast Asia are in the floodplains of large river networks. Under natural conditions, these aquifers would discharge into nearby rivers; however, large-scale groundwater pumping has reversed the flow in some areas so that rivers now recharge aquifers. At a field site near Hanoi Vietnam, we find river water recharging the aquifer becomes high in arsenic, reaching concentrations above 1000 µg/L, within the upper meter of recently (50 µg/L) aqueous arsenic concentrations are found in aquifer regions adjacent to zones where the river has recently deposited sediment and low arsenic concentrations are found in aquifer regions adjacent to erosional zones. High arsenic concentrations are even found adjacent to a depositional river reach in a Pleistocene aquifer, a type of aquifer sediment which generally hosts low arsenic water. Using geochemical and isotopic data, we estimate the in situ rate of arsenic release from riverbed sediments to be up to 1000 times the rates calculated on inland aquifer sediments in Vietnam. Geochemical data for riverbed porewater conditions indicate that the reduction of reactive, poorly crystalline iron oxides controls arsenic release. We suggest that aquifers in these regions may be susceptible to further arsenic contamination where riverine recharge drawn into aquifers by extensive groundwater pumping flows through recently deposited river sediments before entering the aquifer.

  7. Using pressure and volumetric approaches to estimate CO2 storage capacity in deep saline aquifers

    NARCIS (Netherlands)

    Thibeau, S.; Bachu, S.; Birkholzer, J.; Holloway, S.; Neele, F.P.; Zou, Q.

    2014-01-01

    Various approaches are used to evaluate the capacity of saline aquifers to store CO2, resulting in a wide range of capacity estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches. We present four full-scale aquifer cases, where

  8. Legal and regulatory issues affecting aquifer thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, P.L.

    1981-10-01

    This document updates and expands the report with a similar title issued in October 1980. This document examines a number of legal and regulatory issues that potentially can affect implementation of the aquifer thermal energy storage (ATES) concept. This concept involves the storage of thermal energy in an underground aquifer until a later date when it can be effectively utilized. Either heat energy or chill can be stored. Potential end uses of the energy include district space heating and cooling, industrial process applications, and use in agriculture or aquaculture. Issues are examined in four categories: regulatory requirements, property rights, potential liability, and issues related to heat or chill delivery.

  9. Origin and residence time of water in the Lima Aquifer

    CERN Document Server

    Montoya, Modesto

    2014-01-01

    The 8 million inhabitants of the coast Lima City are supplied with water from Rimac and Chillons rivers and water wells in the Lima aquifer. Historics of Rimac River flow and static level of water level in wells are correlated in order to calculate residence time of water since the aquifer is recharged by Rimac River until water reaches a well located 12 km farther, in Miraflores district near sea. Relative abundances of 2H and 18O are used to identify origins of waters from those wells. 3H and 14C contents, respectively, are used to estimate ages of waters.

  10. University of Minnesota Aquifer Thermal Energy Storage Field Test Facility

    Science.gov (United States)

    Walton, M.; Hoyer, M. C.

    1982-12-01

    The University of Minnesota Aquifer Thermal Energy Storage (ATES) Field Test Facility became operational. Experiments demonstrated that the Franconia-Ironton-Galesville aquifer will accept injection of 300 gpm (18.9 1 sec (-1)) at reasonable pressures with a heat buildup in the injection well of about 44 psi (31.6 m) over 8 days. Heating of the ground water caused precipitation of carbonate in the piping and injection well, but with proper water conditioning, the system will work satisfactorily at elevated temperatures.

  11. Global assessment of coastal aquifer state and its vulnerability respect to Sea Water Intrusion. Application to several Mediterranean Coastal Aquifers.

    Science.gov (United States)

    Baena, Leticia; Pulido-Velazquez, David; Renau-Pruñonosa, Arianna; Morell, Ignacio

    2017-04-01

    In this research we propose a method for a global assessment of coastal aquifer state and its vulnerability to Sea Water Intrusion (SWI). It is based on two indices, the MART index, which summarize the global significance of the SWI phenomenon, and the L_GALDIT for a lumped assessment of the vulnerability to SWI. Both of them can be useful as a tool to assess coastal groundwater bodies in risk of not achieving good status in accordance with the Water Framework Directive (WFD, 2000) and to identify possible management alternative to reduce existing impacts. They can be obtained even from a reduced number of data (in the MART case only depend on the geometry and available aquifer state data) with simple calculations, which have been implemented in a general GIS tool that can be easily applied to other case studies. The MART index in an aquifer is related with the total mass of chloride in the aquifer due to sea water intrusion and can be obtained by simple linear operations of volume and concentrations that can be deduced from a schematic conceptual cross-section approach (orthogonal to the shore line) defined to summarize the intrusion volume in the aquifer. At a certain historical time, this representative aquifer cross-section can be defined in a systhematic way from the aquifer geometry, the specific yield, and the hydraulic head and chloride concentration fields that can be deduced from the available information by using appropriate interpolation methods. Following the proposed procedure we will finally obtain a summary of the historical significance of the SWI in an aquifer at different spatial resolution: 3D salinity concentration maps, 2D representative conceptual cross-section of intrusion and the MART lumped significance index. The historical evolution of the MART can be employed to perform a global assessment of the resilience and trends of global significance of the SWI in an aquifer. It can be useful to compare the significance of intrusion problems in

  12. Accepting managed aquifer recharge of urban storm water reuse: The role of policy-related factors

    Science.gov (United States)

    Mankad, Aditi; Walton, Andrea

    2015-12-01

    A between-groups experimental design examined public acceptance for managed aquifer recharge of storm water for indirect potable and nonpotable reuse; acceptance was based on five policy-related variables (fairness, effectiveness, trust, importance of safety assurances, and importance of communication activities). Results showed that public acceptance (N = 408) for managed aquifer recharge of storm water was higher for nonpotable applications, as was the importance of safety assurances. Analyses of variance also showed that perceptions of fairness and effectiveness were higher for a nonpotable scheme, but not trust. A three-step hierarchical regression (Step 1: age, gender, education, and income; Step 2: type of use; Step 3: fairness, effectiveness, trust, safety assurance, and communication activities) demonstrated that type of storm water use and the policy-related factors accounted for 73% of the variance in acceptance of storm water (R2 = 0.74, adjusted R2 = 0.74, F (10, 397) = 113.919, p related factors were also significant individual predictors of acceptance. The most important predictors were perceptions of trust in water authorities, perceptions of effectiveness, and perceptions of fairness. Interestingly, while safety assurance was important in attitudinal acceptance of managed aquifer recharge based on type of use, safety assurance was not found to be significant predictor of acceptance. This research suggests that policy-makers should look to address matters of greater public importance and drive such as fairness, trust, and effectiveness of storm water programs and advocate these at the forefront of their policies, rather than solely on education campaigns.

  13. Quantifying spatio-temporal stream-aquifer water exchanges along a multi-layer aquifer system using LOMOS and hydro-thermo modelling

    Science.gov (United States)

    Mouhri, Amer; flipo, Nicolas; Rejiba, Fayçal; Bodet, Ludovic; Jost, Anne; Goblet, Patrick

    2014-05-01

    The aim of this work is to understand the spatial and temporal variability of stream-aquifer water exchanges along a 6 km-stream network in a multi-layer aquifer system using both LOcal MOnitoring Stations (LOMOSs) coupled with the optimization of a hydro-thermo model per LOMOS. With an area of 45 km2, the Orgeval experimental basin is located 70 km east from Paris. It drains a multi-layer aquifer system, which is composed of two main geological formations: the Oligocene (upper aquifer unit) and the Eocene (lower aquifer unit). These two aquifer units are separated by a clayey aquitard. The connectivity status between streams and aquifer units has been evaluated using near surface geophysical investigations as well as drill cores. Five LOMOSs of the stream-aquifer exchanges have been deployed along the stream-network to monitor stream-aquifer exchanges over years, based on continuous pressure and temperature measurements (15 min-time step). Each LOMOS is composed of one or two shallow piezometers located 2 to 3 m away from the river edge; one surface water monitoring system; two hyporheic zone temperature profiles located close to each river bank. The five LOMOSs are distributed in two upstream, two intermediate, and one downstream site. The two upstream sites are connected to the upper aquifer unit, and the downstream one is connected to the lower aquifer unit. The 2012-April - 2013-december period of hydrological data are hereafter analyzed. We first focus on the spatial distribution of the stream-aquifer exchanges along the multi-layer aquifer system during the low flow period. Results display an upstream-downstream functional gradient, with upstream gaining stream and downstream losing stream. This spatial distribution is due to the multi-layer nature of the aquifer system, whose lower aquifer unit is depleted. Then it appears that the downstream losing streams temporally switch into gaining ones during extreme hydrological events, while the upstream streams

  14. Review: Groundwater flow and transport modeling of karst aquifers, with particular reference to the North Coast Limestone aquifer system of Puerto Rico.

    Science.gov (United States)

    Ghasemizadeh, Reza; Hellweger, Ferdinand; Butscher, Christoph; Padilla, Ingrid; Vesper, Dorothy; Field, Malcolm; Alshawabkeh, Akram

    2012-12-01

    Karst systems have a high degree of heterogeneity and anisotropy, which makes them behave very differently from other aquifers. Slow seepage through the rock matrix and fast flow through conduits and fractures result in a high variation in spring response to precipitation events. Contaminant storage occurs in the rock matrix and epikarst, but contaminant transport occurs mostly along preferential pathways that are typically inaccessible locations, which makes modeling of karst systems challenging. Computer models for understanding and predicting hydraulics and contaminant transport in aquifers make assumptions about the distribution and hydraulic properties of geologic features that may not always apply to karst aquifers. This paper reviews the basic concepts, mathematical descriptions, and modeling approaches for karst systems. The North Coast Limestone aquifer system of Puerto Rico (USA) is introduced as a case study to illustrate and discuss the application of groundwater models in karst aquifer systems to evaluate aquifer contamination.

  15. Review: Groundwater flow and transport modeling of karst aquifers, with particular reference to the North Coast Limestone aquifer system of Puerto Rico

    Science.gov (United States)

    Ghasemizadeh, Reza; Hellweger, Ferdinand; Butscher, Christoph; Padilla, Ingrid; Vesper, Dorothy; Field, Malcolm; Alshawabkeh, Akram

    2013-01-01

    Karst systems have a high degree of heterogeneity and anisotropy, which makes them behave very differently from other aquifers. Slow seepage through the rock matrix and fast flow through conduits and fractures result in a high variation in spring response to precipitation events. Contaminant storage occurs in the rock matrix and epikarst, but contaminant transport occurs mostly along preferential pathways that are typically inaccessible locations, which makes modeling of karst systems challenging. Computer models for understanding and predicting hydraulics and contaminant transport in aquifers make assumptions about the distribution and hydraulic properties of geologic features that may not always apply to karst aquifers. This paper reviews the basic concepts, mathematical descriptions, and modeling approaches for karst systems. The North Coast Limestone aquifer system of Puerto Rico (USA) is introduced as a case study to illustrate and discuss the application of groundwater models in karst aquifer systems to evaluate aquifer contamination. PMID:23645996

  16. Hydrogeological evaluation of an over-exploited aquifer in Dhaka, Bangladesh towards the implementation of groundwater artificial recharge

    Science.gov (United States)

    Azizur Rahman, M.; Rusteberg, Bernd; Sauter, Martin

    2010-05-01

    The population of Dhaka City is presently about 12 million and according to present trends in population growth, that number will most likely increase to 17.2 million by the year 2025. A serious water crisis is expected due to the extremely limited quality and quantity of water resources in the region. Previous studies have shown that the current trend in groundwater resource development is non-sustainable due to over-exploitation of the regional aquifer system, resulting in rapidly decreasing groundwater levels of about 2 to 3 meters per year. Today, annual groundwater extraction clearly exceeds natural groundwater recharge. New water management strategies are needed to guarantee future generations of Dhaka City a secured and sustained water supply as well as sustainable development of the city. The implementation of groundwater artificial recharge (AR) is one potential measure. As the first step towards a new water management strategy for Dhaka City, the authors report on the hydrogeological conditions of the greater Dhaka region and from this are able to present the location of potential recharge sites and identify appropriate recharge technologies for AR implementation. The aquifers of greater Dhaka can be grouped in three major categories: Holocene Deposit, Pleistocene Deposit and Plio-Pleistocene Deposit. The aquifers are generally thick and multilayered with relatively high transmissivity and storage coefficients. AR is considered feasible due to the fact these aquifers are alluvium deposit aquifers which characteristically have moderate to high hydraulic conductivity. Low costs for recovery of recharged water and large recharge volume capacity are generally associated with aquifers of unconsolidated sediments. Spatial analysis of the region has shown that Karaniganj, Kotoali, Savar, Dhamrai, Singair upazila, which are situated in greater Dhaka region and close to Dhaka City, could serve as recharge sites to the subsurface by pond infiltration technique. A

  17. Estimation of hydraulic parameters from an unconfined aquifer test conducted in a glacial outwash deposit, Cape Cod, Massachusetts

    Science.gov (United States)

    Moench, A.F.; Garabedian, Stephen P.; LeBlanc, Denis R.

    2000-01-01

    heterogeneity at the site were small as measured drawdowns in all piezometers and wells were very close to the simulated values for a homogeneous porous medium. The estimated values are: specific yield, 0.26; saturated thickness, 170 feet; horizontal hydraulic conductivity, 0.23 feet per minute; vertical hydraulic conductivity, 0.14 feet per minute; and specific storage, 1.3x10-5 per foot. It was found that drawdown in only a few piezometers strategically located at depth near the pumped well yielded parameter estimates close to the estimates obtained for the entire data set analyzed simultaneously. If the influence of gradual drainage from the unsaturated zone is not taken into account, specific yield is significantly underestimated even in these deep-seated piezometers. This helps to explain the low values of specific yield often reported for granular aquifers in the literature. If either the entire data set or only the drawdown in selected deep-seated piezometers was used, it was found unnecessary to conduct the test for the full 72-hours to obtain accurate estimates of the hydraulic parameters. For some piezometer groups, practically identical results would be obtained for an aquifer test conducted for only 8-hours. Drawdowns measured in the pumped well and piezometers at distant locations were diagnostic only of aquifer transmissivity.

  18. Selected techniques for monitoring water movement through unsaturated alluvium during managed aquifer recharge

    Science.gov (United States)

    Nawikas, Joseph M.; O'Leary, David R.; Izbicki, John A.; Burgess, Matthew K.

    2016-10-21

    Managed aquifer recharge is used to augment natural recharge to aquifers. It can be used to replenish aquifers depleted by pumping or to store water during wetter years for withdrawal during drier years. Infiltration from ponds is a commonly used, inexpensive approach for managed aquifer recharge.At some managed aquifer-recharge sites, the time when infiltrated water arrives at the water table is not always clearly shown by water-level data. As part of site characterization and operation, it can be desirable to track downward movement of infiltrated water through the unsaturated zone to identify when it arrives at the water table.

  19. Potential of using arsenic-safe aquifers as sustainable drinking water sources in arsenic-affected areas of Bengal basin, India and Bangladesh

    Science.gov (United States)

    Bhattacharya, Prosun; Mukherjee, Abhijit; Biswas, Ashis; Hossain, Mohammed; von Brömssen, Mattias

    2016-04-01

    horizontal flow system, and ii) a number of shallow local flow systems. It was confirmed that groundwater irrigation, locally, affects the hydraulic heads at deeper depths. The aquifer system is however fully recharged during the monsoon. Groundwater abstraction for drinking water purposes in rural areas poses little threat for cross-contamination. Installing irrigation- or high capacity drinking water supply wells at deeper depths is however strongly discouraged and assessing sustainability of targeted low-As aquifers remain a main concern. Delineation of safe aquifer(s) that can be targeted by cheap drilling technology for tubewell (TW) installation becomes highly imperative to ensure access to safe and sustainable drinking water sources for the As-affected population in Bengal Basin. In order to replicate the salient outcomes of the Matlab study results, an investigation was carried out in West Bengal, India covering an area of ˜100 km2 to investigate the potentiality of brown sand aquifers (BSA) as a safe drinking water source which is currently being practiced in the area for safe tubewell installation. The results revealed salient hydrogeochemical contrasts within the sedimentary sequence designated as shallow grey sand aquifers (GSA) and the brown sand aquifers (BSA) within shallow depth (perceived by the local driller in Matlab. Although the major ion compositions indicated close similarity, the redox conditions were markedly different in groundwater abstracted from the two group of aquifers. The redox condition in the BSA is delineated to be Mn oxy-hydroxide reducing, not sufficiently lowered for As mobilization into groundwater. In contrast, lower Eh in groundwater of GSA, along with the enrichments of NH4+, PO43-, Fe and As reflect reductive dissolution of Fe-oxyhydroxide coupled to microbially mediated oxidation of organic matter as the prevailing redox process causing As mobilization into groundwater of this aquifer type. The outcomes of the study has thus

  20. Aquifer Storage and Recovery : Physical and Geochemical Modelling (SWIFTPHREEQC)of British Aquifers for Aquifer Storage and Recovery Purposes. Part 1, physical modelling and geochemical model calibration

    OpenAIRE

    2000-01-01

    This report describes the progress that has been made in developing models simulating both the physical and geochemical aspects of Aquifer Storage Recovery (ASR) schemes. This work is part of a 30 month project, entitled ASR-UK, which started in April 1999. The report describes progress to the end of 1999. SWIFT is a fully transient 3-Dimensional model that simulates flow and transport of fluids. It is ideally suited to modelling ASR and has been used to simulate the response o...

  1. Sustainable yields from large diameter wells in shallow weathered aquifers

    Science.gov (United States)

    Rushton, K. R.; de Silva, C. S.

    2016-08-01

    Large diameter wells in shallow weathered aquifers provide a valuable source of water for domestic and agricultural purposes in many locations including the Indian subcontinent. However, when used for irrigation, these wells often fail towards the end of the dry season. By considering two case studies in the dry and intermediate rainfall zones of Sri Lanka, reasons for the limited yield of these wells are identified. The first case study is concerned with a sloping catchment; a significant proportion of the precipitation during the rainy season either becomes runoff or passes down-gradient through the aquifer and is discharged at the ground surface. Furthermore, during the dry season, groundwater discharge continues. In the second case study the topography is generally flat but, even though the aquifer fills most years during the rainy season, there is often only sufficient water to irrigate about half of each farmer's holding. These investigations are based on field information and the development of conceptual and computational models. Of critical importance in assessing the long term yield of a well is the formation of a seepage face on the side of the well, with the water table a significant distance above the pumping water level. Consequently the water table may only be lowered to about half the depth of the well. The paper concludes with recommendations for the exploitation of groundwater from shallow weathered aquifers to minimise the risk of failure during the dry season.

  2. Hydrodynamic characterization of the Paleocene aquifer in the ...

    African Journals Online (AJOL)

    user

    2009-05-15

    May 15, 2009 ... aquifer in the coastal sedimentary basin of Togo. Gnazou M. D. T.1* ... coastal basin sup- ports one third of the national population in a 3450 km² ... ness of the unsaturated zone), and to a rainfall deficit. (Hubert et al., 1989).

  3. Combination of aquifer thermal energy storage and enhanced bioremediation

    NARCIS (Netherlands)

    Ni, Zhuobiao; Gaans, van Pauline; Smit, Martijn; Rijnaarts, Huub; Grotenhuis, Tim

    2016-01-01

    To meet the demand for sustainable energy, aquifer thermal energy storage (ATES) is widely used in the subsurface in urban areas. However, contamination of groundwater, especially with chlorinated volatile organic compounds (CVOCs), is often being encountered. This is commonly seen as an impedime

  4. Thermal performance and heat transport in aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Doornenbal, P.J.; Drijver, B.C.; Gaans, van P.F.M.; Leusbrock, I.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2014-01-01

    Aquifer thermal energy storage (ATES) is used for seasonal storage of large quantities of thermal energy. Due to the increasing demand for sustainable energy, the number of ATES systems has increased rapidly, which has raised questions on the effect of ATES systems on their surroundings as well as t

  5. Focus on CSIR research in water resource: Aquifer dependent ecosystems.

    CSIR Research Space (South Africa)

    Colvin, C

    2007-08-01

    Full Text Available of rivers. In terrestrial and riparian ecosystems, groundwater is not seen at the surface but is tapped by plants and used as ‘cryptic’ discharge. ADEs are important indicators of aquifer health and flow regimes. An oasis is a classic ADE, and like many...

  6. Estimating 14C groundwater ages in a methanogenic aquifer

    Science.gov (United States)

    Aravena, Ramon; Wassenaar, Leonard I; Plummer, L. Niel

    1995-01-01

    This paper addresses the problem of 14C age dating of groundwaters in a confined regional aquifer affected by methanogenesis. Increasing CH4 concentrations along the groundwater flow system and 13C and 14C isotopic data for dissolved inorganic carbon, dissolved organic carbon, and CH4 clearly show the effect of methanogenesis on groundwater chemistry. Inverse reaction path modeling using NETPATH indicates the predominant geochemical reactions controlling the chemical evolution of groundwater in the aquifer are incongruent dissolution of dolomite, ion exchange, methanogenesis, and oxidation of sedimentary organic matter. Modeling of groundwater 14C ages using NETPATH indicates that a significant part of groundwater in the Alliston aquifer is less than 13,000 years old; however, older groundwater in the range of 15,000–23,000 years is also present in the aquifer. This paper demonstrates that 14C ages calculated using NETPATH, incorporating the effects of methanogenesis on the carbon pools, provide reasonable groundwater ages that were not possible by other isotopic methods.

  7. Hot Spots and Persistence of Nitrate in Aquifers Across Scales

    Directory of Open Access Journals (Sweden)

    Dipankar Dwivedi

    2016-01-01

    Full Text Available Nitrate-N (NO3 -- N is one of the most pervasive contaminants in groundwater. Nitrate in groundwater exhibits long-term behavior due to complex interactions at multiple scales among various geophysical factors, such as sources of nitrate-N, characteristics of the vadose zone and aquifer attributes. To minimize contamination of nitrate-N in groundwater, it is important to estimate hot spots (>10 mg/L of NO3 -- N, trends and persistence of nitrate-N in groundwater. To analyze the trends and persistence of nitrate-N in groundwater at multiple spatio-temporal scales, we developed and used an entropy-based method along with the Hurst exponent in two different hydrogeologic settings: the Trinity and Ogallala Aquifers in Texas at fine (2 km × 2 km, intermediate (10 km × 10 km and coarse (100 km × 100 km scales. Results show that nitrate-N exhibits long-term persistence at the intermediate and coarse scales. In the Trinity Aquifer, overall mean nitrate-N has declined with a slight increase in normalized marginal entropy (NME over each decade from 1940 to 2008; however, the number of hot spots has increased over time. In the Ogallala Aquifer, overall mean nitrate-N has increased with slight moderation in NME since 1940; however, the number of hot spots has significantly decreased for the same period at all scales.

  8. Modelling karst aquifer evolution in fractured, porous rocks

    Science.gov (United States)

    Kaufmann, Georg

    2016-12-01

    The removal of material in soluble rocks by physical and chemical dissolution is an important process enhancing the secondary porosity of soluble rocks. Depending on the history of the soluble rock, dissolution can occur either along fractures and bedding partings of the rock in the case of a telogenetic origin, or within the interconnected pore space in the case of eogenetic origin. In soluble rocks characterised by both fractures and pore space, dissolution in both flow compartments is possible. We investigate the dissolution of calcite both along fractures and within the pore space of a limestone rock by numerical modelling. The limestone rock is treated as fractured, porous aquifer, in which the hydraulic conductivity increases with time both for the fractures and the pore spaces. We show that enlargement of pore space by dissolution will accelerate the development of a classical fracture-dominated telogenetic karst aquifer, breakthrough occurs faster. In the case of a pore-controlled aquifer as in eogenetic rocks, enlargement of pores results in a front of enlarged pore spaces migrating into the karst aquifer, with more homogeneous enlargement around this dissolution front, and later breakthrough.

  9. Hydrogeology of the Western Amazon Aquifer System (WAAS)

    Science.gov (United States)

    Rosário, Fátima Ferreira do; Custodio, Emilio; Silva, Gerson Cardoso da, Jr.

    2016-12-01

    The Western Amazon Aquifer System (WAAS), as defined and proposed in the present work, encompasses an area of about 2.0·106 km2 located in the northwestern portion of South America. Published and unpublished data were used to define WAAS boundaries and main hydrogeologic characteristics. Petroleum industry data, environmental data, and other diverse thematic data were compiled for this study according to the data's origin. The analysis, treatment and integration of available data allowed us to define the WAAS as a multilayered aquifer system comprised of the Tertiary Solimões Aquifer System (SAS) and the Cretaceous Tikuna Aquifer System (TAS). The thick clay-rich basal strata of the SAS appear to confine the TAS. The SAS is widely used for both domestic and industrial purposes, providing good quality freshwater. The TAS has varying water quality: it contains freshwater near its recharge areas in the Sub-Andean fault belt zone, brackish to brine water in the Sub-Andean basins, and salty water in the Solimões Basin (Brazil). The interpretation and conclusions provided by an increasing understanding of the area's hydrogeology resulting from this work made it possible to propose an improved and new WAAS regional hydrogeologic conceptual model with data and descriptions not previously available. Some surprising results have been later confirmed as true by looking at unpublished reports, logs and field notes. Therefore, this work resulted in new findings and settled the basis for future works, especially for the poorly understood TAS.

  10. Classification of aquifer vulnerability using K-means cluster analysis

    Science.gov (United States)

    Javadi, S.; Hashemy, S. M.; Mohammadi, K.; Howard, K. W. F.; Neshat, A.

    2017-06-01

    Groundwater is one of the main sources of drinking and agricultural water in arid and semi-arid regions but is becoming increasingly threatened by contamination. Vulnerability mapping has been used for many years as an effective tool for assessing the potential for aquifer pollution and the most common method of intrinsic vulnerability assessment is DRASTIC (Depth to water table, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone and hydraulic Conductivity). An underlying problem with the DRASTIC approach relates to the subjectivity involved in selecting relative weightings for each of the DRASTIC factors and assigning rating values to ranges or media types within each factor. In this study, a clustering technique is introduced that removes some of the subjectivity associated with the indexing method. It creates a vulnerability map that does not rely on fixed weights and ratings and, thereby provides a more objective representation of the system's physical characteristics. This methodology was applied to an aquifer in Iran and compared with the standard DRASTIC approach using the water quality parameters nitrate, chloride and total dissolved solids (TDS) as surrogate indicators of aquifer vulnerability. The proposed method required only four of DRASTIC's seven factors - depth to groundwater, hydraulic conductivity, recharge value and the nature of the vadose zone, to produce a superior result. For nitrate, chloride, and TDS, respectively, the clustering approach delivered Pearson correlation coefficients that were 15, 22 and 5 percentage points higher than those obtained for the DRASTIC method.

  11. Reactivity of Organic Matter and other Reductants in Aquifer Sediments

    NARCIS (Netherlands)

    Hartog, N.

    2003-01-01

    The molecular composition and the carbon isotope signature of sedimentary organic matter (SOM) and indicate that SOM is predominantly derived from higher land plants in sediments of both terrestrial as marine origins. The reactivity of SOM in the aquifer sediments studied is determined by the extent

  12. Hydraulic characterization from porous aquifers of the Brazilian Federal District

    Directory of Open Access Journals (Sweden)

    Tatiana Diniz Gonçalves

    Full Text Available Hydraulic conductivity (K in unsaturated soil is a key input parameter for modeling subsurface water and solute movements. K-values are also important to better define the potential of aquifers and to optimize water resources management activities. Since K-values are usually not readily available, different techniques are applied to estimate them. This study aimed to estimate unsaturated K-values from porous aquifers found in the Federal District of Brazil. Infiltration tests were conducted in different soil types using the open-end-hole approach and the permeability test using shallow boreholes with specific depths, as reported by Heitfeld in 1979. Soil structure was taken into consideration in such estimations. In order to consider important soil properties such as soil texture and bulk density, K-values were also estimated by means of pedotransfer functions (PTFs. Soil texture was determined in the laboratory and used as input parameter for PTFs. Results from open-end-hole method and permeability test compared to those obtained from pedotransfer functions. K-values from four different shallow porous aquifers systems encountered in the Federal District varied from 10-8 ms-1 to 10-6ms-1. Highest K-values were found in Oxisols while the lowest rates were found in Inceptisols. Decreasing conductivity trend was found with increasing depth due to the increase of loamy soils. Variations in the rate of hydraulic conductivity indicated heterogeneity of porous aquifers due to differences in textural and structural characteristics of the soils.

  13. Extended geothermal potential of clastic aquifers by hydraulic stimulation

    NARCIS (Netherlands)

    Veldkamp, J.G.; Pluymaekers, M.P.D.; Wees, J.D.A.M.

    2014-01-01

    We evaluated the implications of hydraulic stimulation in a Dutch context for low permeability clastic aquifers at a depth of 2000 to 4000 m, whose transmissivity has been mapped in the framework of the Dutch subsurface information system on geothermal energy in the Netherlands. For the simulation a

  14. REACTIVE MINERALS IN AQUIFERS: FORMATION PROCESSES AND QUANTITATIVE ANALYSIS

    Science.gov (United States)

    The presentation will focus on the occurrence, form, and characterization of reactive iron minerals in aquifers and soils. The potential for abiotic reductive transformations of contaminants at the mineral-water interface will be discussed along with available tools for site min...

  15. Recovery of energetically overexploited urban aquifers using surface water

    Science.gov (United States)

    García-Gil, Alejandro; Vázquez-Suñé, Enric; Sánchez-Navarro, José Ángel; Mateo Lázaro, Jesús

    2015-12-01

    Shallow aquifers have an important role in reducing greenhouse gases through helping manage the temperature of urban environments. Nevertheless, the uncontrolled rapid use of shallow groundwater resources to heat or cool urban environments can cause thermal pollution that will limit the long term sustainability of the resource. Therefore, there is a need for appropriate mitigation/remediation strategies capable of recovering energetically overexploited aquifers. In this work, a novel remediation strategy based on surface water recharge into aquifers is presented. To evaluate the capabilities of such measures for effective remediation, this strategy is optimized for a management problem raised in the overheated "Urban Alluvial Aquifer of Zaragoza" (Spain). The application of a transient groundwater flow and heat transport model under 512 different mitigation scenarios has enabled to quantify and discuss the magnitude of the remediation effect as a respond to injection rates of surface water, seasonal schedule of the injection and location of injection. The quantification of the relationship between these variables together with the evaluation of the amount of surface water injected per year in each scenario proposed have provided a better understanding of the system processes and an optimal management alternative. This work also makes awareness of the magnitude of the remediation procedure which is in an order of magnitude of tenths of years.

  16. Determining Changes in Groundwater Quality during Managed Aquifer Recharge

    Science.gov (United States)

    Gambhir, T.; Houlihan, M.; Fakhreddine, S.; Dadakis, J.; Fendorf, S. E.

    2016-12-01

    Managed aquifer recharge (MAR) is becoming an increasingly prevalent technology for improving the sustainability of freshwater supply. However, recharge water can alter the geochemical conditions of the aquifer, mobilizing contaminants native to the aquifer sediments. Geochemical alterations on deep (>300 m) injection of highly treated recycled wastewater for MAR has received limited attention. We aim to determine how residual disinfectants used in water treatment processes, specifically the strong oxidants chloramine and hydrogen peroxide, affect metal mobilization within deep injection wells of the Orange County Water District. Furthermore, as the treated recharge water has very low ionic strength (44.6 mg L-1 total dissolved solids), we tested how differing concentrations of magnesium chloride and calcium chloride affected metal mobilization within deep aquifers. Continuous flow experiments were conducted on columns dry packed with sediments from a deep injection MAR site in Orange County, CA. The effluent was analyzed for shifts in water quality, including aqueous concentrations of arsenic, uranium, and chromium. Interaction between the sediment and oxic recharge solution causes naturally-occurring arsenopyrite to repartition onto iron oxides. The stability of arsenic on the newly precipitated iron oxides is dependent on pH changes during recharge.

  17. Lithological and Structural Controls on the Development of Aquifer ...

    African Journals Online (AJOL)

    Bheema

    Overall thickness of the rocks as measured from the section is about 200m and they range in ..... and hydraulic conductivity of the aquifer in this formation reach up to 32.92 m2/day ... The columnar joints cause anisotropy and strong vertical.

  18. Activity and diversity of methanogens in a petroleum hydrocarbon-contaminated aquifer.

    Science.gov (United States)

    Kleikemper, Jutta; Pombo, Silvina A; Schroth, Martin H; Sigler, William V; Pesaro, Manuel; Zeyer, Josef

    2005-01-01

    Methanogenic activity was investigated in a petroleum hydrocarbon-contaminated aquifer by using a series of four push-pull tests with acetate, formate, H(2) plus CO(2), or methanol to target different groups of methanogenic Archaea. Furthermore, the community composition of methanogens in water and aquifer material was explored by molecular analyses, i.e., fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes amplified with the Archaea-specific primer set ARCH915 and UNI-b-rev, and sequencing of DNA from dominant DGGE bands. Molecular analyses were subsequently compared with push-pull test data. Methane was produced in all tests except for a separate test where 2-bromoethanesulfonate, a specific inhibitor of methanogens, was added. Substrate consumption rates were 0.11 mM day(-1) for methanol, 0.38 mM day(-1) for acetate, 0.90 mM day(-1) for H(2), and 1.85 mM day(-1) for formate. Substrate consumption and CH(4) production during all tests suggested that at least three different physiologic types of methanogens were present: H(2) plus CO(2) or formate, acetate, and methanol utilizers. The presence of 15 to 20 bands in DGGE profiles indicated a diverse archaeal population. High H(2) and formate consumption rates agreed with a high diversity of methanogenic Archaea consuming these substrates (16S rRNA gene sequences related to several members of the Methanomicrobiaceae) and the detection of Methanomicrobiaceae by using FISH (1.4% of total DAPI [4',6-diamidino-2-phenylindole]-stained microorganisms in one water sample; probe MG1200). Considerable acetate consumption agreed with the presence of sequences related to the obligate acetate degrader Methanosaeata concilii and the detection of this species by FISH (5 to 22% of total microorganisms; probe Rotcl1). The results suggest that both aceticlastic and CO(2)-type substrate-consuming methanogens are likely involved in the terminal step of hydrocarbon degradation

  19. Lateral groundwater inflows into alluvial aquifers of main alpine valleys

    Science.gov (United States)

    Burger, Ulrich

    2015-04-01

    In alpine regions the topography is mainly characterised by deep incised valleys, mountain slopes and ridges. Usually the main valleys contain aquifers in alluvial soft rock. Lateral these aquifers are confined by mountainous hard rock slopes covered by heterogeneous sediments with different thickness. The slopes can be incised by lateral valleys. Numerical models for the main alluvial aquifers ask for lateral hydrogeological boundaries. Usually no flow boundaries or Constant head Boundaries are used, even if the lateral inflows to the main aquifers are rarely known. In this example a data set for a detailed investigated and monitored area is studied to give an answer on the location and the quantification of these lateral subsurface inflows. The study area is a typical main alpine valley with a thick alluvial aquifer (appr. 120m thick), lateral confined by granite, covered at the base of the steep slopes by quaternary sediments (Burger at al. 2012). The study consists of several steps 1.) Analytical calculation of the inflows on the base of investigated and monitored 2d profiles along fault zones (Perello et al 2013) which pinch out in the main valley 2.) Analytical models along typical W-dipping slopes with monitored slope springs 3.) Evaluating temperature and electrical conductivity profiles measured in approx. 30 groundwater wells in the alluvial aquifers and along the slopes to locate main lateral subsurface inflows 4.) Output of a regional model used for the hydrogeological back analyses of the excavation of a tunnel (Baietto et al. 2014) 5.) Output of a local numerical model calibrated with a monitoring dataset and results of a pumping test of big scale (450l/s for 10days) Results of these analyses are shown to locate and quantify the lateral groundwater inflows in the main alluvial aquifer. References Baietto A., Burger U., Perello P. (2014): Hydrogeological modelling applications in tunnel excavations: examples from tunnel excavations in granitic rocks

  20. Water-level conditions in the confined aquifers of the New Jersey Coastal Plain, 2008

    Science.gov (United States)

    Depaul, Vincent T.; Rosman, Robert

    2015-01-01

    Groundwater-level altitudes in 10 confined aquifers of the New Jersey Coastal Plain were measured and evaluated to provide an overview of regional groundwater conditions during fall 2008. Water levels were measured in more than 900 wells in New Jersey, eastern Pennsylvania, and northern Delaware and potentiometric surface maps prepared for the confined Cohansey aquifer of Cape May County, the Rio Grande water-bearing zone, the Atlantic City 800-foot sand, the Piney Point, Vincentown, and the Wenonah-Mount Laurel aquifers, the Englishtown aquifer system, and the Upper, Middle, and Lower aquifers of the Potomac-Raritan-Magothy aquifer system. In 2008, the highest water-level altitudes were observed in the Vincentown aquifer (median, 78 ft) and the lowest in the Atlantic City 800-foot sand (median, -45 ft). Persistent, regionally extensive cones of depression were present within the potentiometric surfaces of the Englishtown aquifer system in east-central New Jersey, the Wenonah-Mount Laurel aquifer in east-central and southern New Jersey, the Upper, Middle, and Lower Potomac-Raritan-Magothy aquifers in southern New Jersey, and the Atlantic City 800-foot sand in the southeastern part of the State. Cones of depression in the potentiometric surfaces of the Upper Potomac-Raritan-Magothy and the Piney Point aquifers in east-central and southwestern New Jersey had broadened and deepened since 2003.

  1. The source of naturally occurring arsenic in a coastal sand aquifer of eastern Australia.

    Science.gov (United States)

    O'Shea, Bethany; Jankowski, Jerzy; Sammut, Jesmond

    2007-07-01

    The discovery of dissolved arsenic in a coastal aquifer used extensively for human consumption has led to widespread concern for its potential occurrence in other sandy coastal environments in eastern Australia. The development of an aquifer specific geomorphic model (herein) suggests that arsenic is regionally derived from erosion of arsenic-rich stibnite (Sb(2)S(3)) mineralisation present in the hinterland. Fluvial processes have transported the eroded material over time to deposit an aquifer lithology elevated in arsenic. Minor arsenic contribution to groundwater is derived from mineralised bedrock below the unconsolidated aquifer. An association with arsenic and pyrite has been observed in the aquifer in small discrete arsenian pyrite clusters rather than actual acid sulfate soil horizons. This association is likely to influence arsenic distribution in the aquifer, but is not the dominant control on arsenic occurrence. Arsenic association with marine clays is considered a function of their increased adsorptive capacity for arsenic and not solely on the influence of sea level inundation of the aquifer sediments during the Quaternary Period. These findings have implications for, but are not limited to, coastal aquifers. Rather, any aquifer containing sediments derived from mineralised provenances may be at risk of natural arsenic contamination. Groundwater resource surveys should thus incorporate a review of the aquifer source provenance when assessing the likely risk of natural arsenic occurrence in an aquifer.

  2. What function tells about structure in heterogeneous aquifers

    Science.gov (United States)

    Lischeid, Gunnar; Steidl, Jörg; Merz, Christoph; Dannowski, Ralf

    2016-04-01

    Hydogeologists and water resources managers are interested in the functional aspects of groundwater systems, that is, the temporal behaviour of groundwater head, patterns of groundwater flow pathways or residence time distribution. These functional aspects highly depend on the structure of the respective aquifer, e.g., on the extent and inclination of confining layers or on the geometry of fissures in hardrock aquifers. Thus a sound knowledge of the prevailing features of the aquifer's structure is a necessary prerequisite for groundwater resources management and application of groundwater models. There is urgent need for efficient ways to extract relevant information from easily available data. When certain structures in the subsurface have a major effect on the functioning of a groundwater system sophisticated analysis of the latter might be used to infer the former in an inverse approach. Then in a next step this information could be used, e.g., for constraining groundwater models. Unless, e.g., for a naïve implementation of geophysical data in groundwater models, the approach outlined here ensures that only structures relevant for hydrogeological functioning are considered, thus minimizing the model structure uncertainty. This approach has been applied in the Quillow catchment in Northeast Germany, a region with a very complex setting of pleistocenic unconsolidated sediments of 200 m thickness, where numerous layers of varying permeability intersect to unknown numbers and extent. Here the key problem is the identification of confining layers that effectively separate different aquifers. Different approaches were combined. Firstly, a principal component analysis was applied to time series of groundwater head from 10 groundwater wells in the study region, allowing to differentiate between different effects on groundwater dynamics. Corresponding to other studies published recently, groundwater head dynamics in the first place depended on the degree of

  3. Nomenclature of regional hydrogeologic units of the Southeastern Coastal Plain aquifer system

    Science.gov (United States)

    Miller, J.A.; Renken, R.A.

    1988-01-01

    Clastic sediments of the Southeastern Coastal Plain aquifer system can be divided into four regional aquifers separated by three regional confining units. The four regional aquifers have been named for major rivers that cut across their outcrop areas and expose the aquifer materials. From youngest to oldest, the aquifers are called the Chickasawhay River, Pearl River, Chattahoochee River, and Black Warrior River aquifers, and the regional confining units separating them are given the same name as the aquifer they overlie. Most of the regional hydrogeologic units are subdivided within each of the four States that comprise the study area. Correlation of regional units is good with hydrogeologic units delineated by a similar regional study to the west and southwest. Because of complexity created by a major geologic structure to the northeast of the study area and dramatic facies change from clastic to carbonate strata to the southeast, correlation of regional hydrogeologic units is poor in these directions. (Author 's abstract)

  4. A new aquifer assessment tool using reactive tracers

    Science.gov (United States)

    McKnight, D.; Smalley, A. L.; Banwart, S. A.; Lerner, D. N.; Thomson, N. R.; Thornton, S. F.; Wilson, R. D.

    2003-04-01

    A major obstacle to making informed decisions about trigger levels for restoration and choosing remediation options is that current Site Investigation (SI) practice fails to make optimal use of available SI techniques resulting in poor value for money in conceptual site models. Often it is simply too expensive to obtain the type of site data required to build the case for natural attenuation, even though this restoration option may be relatively cheaper than a pump-and-treat system. In particular, aquifer property measurement techniques for groundwater transport and reactions are too costly and this results in over-reliance on literature values or model assumptions. This results in overly uncertain predictions of in situ performance and therefore unnecessarily cautious risk assessment and costly remediation strategies. Therefore, cost-effective SI tools that have the capability of producing high quality characterisation data are required. The dipole flow test which circulates groundwater between isolated injection (source) and extraction (sink) chambers within a single borehole has been used successfully by others to delineate heterogeneous hydraulic properties in both highly permeable and fractured rock aquifers. We propose to extend this approach by adding a suite of reactive tracers into a dipole flow field to assess the geochemical properties and biodegradation potential of aquifers. If successful this will provide a method to ascertain site-specific parameters for use in appropriate reactive transport models. The initial phase of this project involves the construction of a laboratory-scale physical model of a dipole probe to investigate the utility of the dipole flow and reactive tracer test (DFRTT) as an aquifer assessment tool. This phase will also serve as the developmental stage between mathematical theory and a host of planned field trials. The development of the laboratory-scale DFRTT including initial scoping calculations, numerical simulation results

  5. Water balance of global aquifers revealed by groundwater footprint.

    Science.gov (United States)

    Gleeson, Tom; Wada, Yoshihide; Bierkens, Marc F P; van Beek, Ludovicus P H

    2012-08-09

    Groundwater is a life-sustaining resource that supplies water to billions of people, plays a central part in irrigated agriculture and influences the health of many ecosystems. Most assessments of global water resources have focused on surface water, but unsustainable depletion of groundwater has recently been documented on both regional and global scales. It remains unclear how the rate of global groundwater depletion compares to the rate of natural renewal and the supply needed to support ecosystems. Here we define the groundwater footprint (the area required to sustain groundwater use and groundwater-dependent ecosystem services) and show that humans are overexploiting groundwater in many large aquifers that are critical to agriculture, especially in Asia and North America. We estimate that the size of the global groundwater footprint is currently about 3.5 times the actual area of aquifers and that about 1.7 billion people live in areas where groundwater resources and/or groundwater-dependent ecosystems are under threat. That said, 80 per cent of aquifers have a groundwater footprint that is less than their area, meaning that the net global value is driven by a few heavily overexploited aquifers. The groundwater footprint is the first tool suitable for consistently evaluating the use, renewal and ecosystem requirements of groundwater at an aquifer scale. It can be combined with the water footprint and virtual water calculations, and be used to assess the potential for increasing agricultural yields with renewable groundwaterref. The method could be modified to evaluate other resources with renewal rates that are slow and spatially heterogeneous, such as fisheries, forestry or soil.

  6. Modeling saltwater intrusion in highly heterogeneous coastal aquifers

    Science.gov (United States)

    Safi, Amir; El-Fadel, Mutasem; Doummar, Joanna; Abou Najm, Majdi; Alameddine, Ibrahim

    2016-04-01

    In this study, a 3D variable-density flow and solute transport model SEAWAT was used to examine the impact of macroscopic variation in a soil matrix on widening or narrowing the thickness of the saltwater-freshwater mixing zone. Located along the Eastern Mediterranean (Beirut), the pilot aquifer consists of karstified limestone of Cretaceous age overlain by Upper Tertiary and Quaternary unconsolidated deposits. The model used the advanced pilot-points parameterization coupled with PEST to characterize spatial heterogeneity. Historically simulated water levels were relied upon to reduce potential numerical instabilities induced by insensitive parameters in transient calibration. The latter demonstrated a high degree of heterogeneity in the middle parts of the aquifer and along western coastlines with specification of a high hydraulic conductivity and low storativity in fault networks. The response of the aquifer to seasonal stresses such as climate cycles, pumping rates and recharge rates was manifested as high fluctuations in potentiometric surface due to potential fast flow pathways along faults. The final distribution of saltwater intrusion supports two mechanisms 1) lateral encroachment of recent seawater into the western zone of the aquifer which is of most concern due to high horizontal hydraulic conductivity in the wave direction and 2) upconing in the northwest and southwest of the aquifer due to large vertical hydraulic conductivities that tend to exacerbate the vertical movement of salinity. Acknowledgments This study is part of a program on climate change and seawater intrusion along the Eastern Mediterranean funded by the International Development Research Center (IDRC) of Canada at the American University of Beirut (AUB). Special thanks are extended to Dr. Charlotte Macalister at IDRC for her support and feedback in implementing this program.

  7. Sources of sulfate supporting anaerobic metabolism in a contaminated aquifer

    Science.gov (United States)

    Ulrich, G.A.; Breit, G.N.; Cozzarelli, I.M.; Suflita, J.M.

    2003-01-01

    Field and laboratory techniques were used to identify the biogeochemical factors affecting sulfate reduction in a shallow, unconsolidated alluvial aquifer contaminated with landfill leachate. Depth profiles of 35S-sulfate reduction rates in aquifer sediments were positively correlated with the concentration of dissolved sulfate. Manipulation of the sulfate concentration in samples revealed a Michaelis-Menten-like relationship with an apparent Km and Vmax of approximately 80 and 0.83 ??M SO4-2??day-1, respectively. The concentration of sulfate in the core of the leachate plume was well below 20 ??M and coincided with very low reduction rates. Thus, the concentration and availability of this anion could limit in situ sulfate-reducing activity. Three sulfate sources were identified, including iron sulfide oxidation, barite dissolution, and advective flux of sulfate. The relative importance of these sources varied with depth in the alluvium. The relatively high concentration of dissolved sulfate at the water table is attributed to the microbial oxidation of iron sulfides in response to fluctuations of the water table. At intermediate depths, barite dissolves in undersaturated pore water containing relatively high concentrations of dissolved barium (???100 ??M) and low concentrations of sulfate. Dissolution is consistent with the surface texture of detrital barite grains in contact with leachate. Laboratory incubations of unamended and barite-amended aquifer slurries supported the field observation of increasing concentrations of barium in solution when sulfate reached low levels. At a deeper highly permeable interval just above the confining bottom layer of the aquifer, sulfate reduction rates were markedly higher than rates at intermediate depths. Sulfate is supplied to this deeper zone by advection of uncontaminated groundwater beneath the landfill. The measured rates of sulfate reduction in the aquifer also correlated with the abundance of accumulated iron sulfide

  8. AUTOMATED WATER LEVEL MEASUREMENTS IN SMALL-DIAMETER AQUIFER TUBES

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN SW; EDRINGTON RS; MAHOOD RO; VANMIDDLESWORTH PE

    2011-01-14

    Groundwater contaminated with hexavalent chromium, strontium-90, and uranium discharges into the Columbia River along approximately 16 km (10 mi) of the shoreline. Various treatment systems have and will continue to be implemented to eliminate the impact of Hanford Site contamination to the river. To optimize the various remediation strategies, it is important to understand interactions between groundwater and the surface water of the Columbia River. An automated system to record water levels in aquifer sampling tubes installed in the hyporheic zone was designed and tested to (1) gain a more complete understanding of groundwater/river water interactions based on gaining and losing conditions ofthe Columbia River, (2) record and interpret data for consistent and defensible groundwater/surface water conceptual models that may be used to better predict subsurface contaminant fate and transport, and (3) evaluate the hydrodynamic influence of extraction wells in an expanded pump-and-treat system to optimize the treatment system. A system to measure water levels in small-diameter aquifer tubes was designed and tested in the laboratory and field. The system was configured to allow manual measurements to periodically calibrate the instrument and to permit aquifer tube sampling without removing the transducer tube. Manual measurements were collected with an e-tape designed and fabricated especially for this test. Results indicate that the transducer system accurately records groundwater levels in aquifer tubes. These data are being used to refine the conceptual and numeric models to better understand interactions in the hyporheic zone of the Columbia River and the adjacent river water and groundwater, and changes in hydrochemistry relative to groundwater flux as river water recharges the aquifer and then drains back out in response to changes in the river level.

  9. Hydrogeologic Framework of the Yakima River Basin Aquifer System, Washington

    Science.gov (United States)

    Vaccaro, J.J.; Jones, M.A.; Ely, D.M.; Keys, M.E.; Olsen, T.D.; Welch, W.B.; Cox, S.E.

    2009-01-01

    The Yakima River basin aquifer system underlies about 6,200 square miles in south-central Washington. The aquifer system consists of basin-fill deposits occurring in six structural-sedimentary basins, the Columbia River Basalt Group (CRBG), and generally older bedrock. The basin-fill deposits were divided into 19 hydrogeologic units, the CRBG was divided into three units separated by two interbed units, and the bedrock was divided into four units (the Paleozoic, the Mesozoic, the Tertiary, and the Quaternary bedrock units). The thickness of the basin-fill units and the depth to the top of each unit and interbed of the CRBG were mapped. Only the surficial extent of the bedrock units was mapped due to insufficient data. Average mapped thickness of the different units ranged from 10 to 600 feet. Lateral hydraulic conductivity (Kh) of the units varies widely indicating the heterogeneity of the aquifer system. Average or effective Kh values of the water-producing zones of the basin-fill units are on the order of 1 to 800 ft/d and are about 1 to 10 ft/d for the CRBG units as a whole. Effective or average Kh values for the different rock types of the Paleozoic, Mesozoic, and Tertiary units appear to be about 0.0001 to 3 ft/d. The more permeable Quaternary bedrock unit may have Kh values that range from 1 to 7,000 ft/d. Vertical hydraulic conductivity (Kv) of the units is largely unknown. Kv values have been estimated to range from about 0.009 to 2 ft/d for the basin-fill units and Kv values for the clay-to-shale parts of the units may be as small as 10-10 to 10-7 ft/d. Reported Kv values for the CRBG units ranged from 4x10-7 to 4 ft/d. Variations in the concentrations of geochemical solutes and the concentrations and ratios of the isotopes of hydrogen, oxygen, and carbon in groundwater provided information on the hydrogeologic framework and groundwater movement. Stable isotope ratios of water (deuterium and oxygen-18) indicated dispersed sources of groundwater recharge to

  10. Investigating groundwater flow between Edwards and Trinity aquifers in central Texas.

    Science.gov (United States)

    Wong, C I; Kromann, J S; Hunt, B B; Smith, B A; Banner, J L

    2014-01-01

    Understanding the nature of communication between aquifers can be challenging when using traditional physical and geochemical groundwater sampling approaches. This study uses two multiport wells completed within Edwards and Trinity aquifers in central Texas to determine the degree of groundwater inter-flow between adjacent aquifers. Potentiometric surfaces, hydraulic conductivities, and groundwater major ion concentrations and Sr isotope values were measured from multiple zones within three hydrostratigraphic units (Edwards and Upper and Middle Trinity aquifers). Physical and geochemical data from the multiport wells were combined with historical measurements of groundwater levels and geochemical compositions from the region to characterize groundwater flow and identify controls on the geochemical compositions of the Edwards and Trinity aquifers. Our results suggest that vertical groundwater flow between Edwards and Middle Trinity aquifers is likely limited by low permeability, evaporite-rich units within the Upper and Middle Trinity. Potentiometric surface levels in both aquifers vary with changes in wet vs. dry conditions, indicating that recharge to both aquifers occurs through distinct recharge areas. Geochemical compositions in the Edwards, Upper, and Middle Trinity aquifers are distinct and likely reflect groundwater interaction with different lithologies (e.g., carbonates, evaporites, and siliceous sediments) as opposed to mixing of groundwater between the aquifers. These results have implications for the management of these aquifers as they indicate that, under current conditions, pumping of either aquifer will likely not induce vertical cross-formational flow between the aquifers. Inter-flow between the Trinity and the Edwards aquifers, however, should be reevaluated as pumping patterns and hydrogeologic conditions change.

  11. Processes affecting geochemistry and contaminant movement in the middle Claiborne aquifer of the Mississippi embayment aquifer system

    Science.gov (United States)

    Katz, Brian G.; Kingsbury, James A.; Welch, Heather L.; Tollett, Roland W.

    2012-01-01

    Groundwater chemistry and tracer-based age data were used to assess contaminant movement and geochemical processes in the middle Claiborne aquifer (MCA) of the Mississippi embayment aquifer system. Water samples were collected from 30 drinking-water wells (mostly domestic and public supply) and analyzed for nutrients, major ions, pesticides, volatile organic compounds (VOCs), and transient age tracers (chlorofluorocarbons, tritium and helium-3, and sulfur hexafluoride). Redox conditions are highly variable throughout the MCA. However, mostly oxic groundwater with low dissolved solids is more vulnerable to nitrate contamination in the outcrop areas east of the Mississippi River in Mississippi and west Tennessee than in mostly anoxic groundwater in downgradient areas in western parts of the study area. Groundwater in the outcrop area was relatively young (apparent age of less than 40 years) with significantly (p 50 m depth) indicated contaminant movement from shallow parts of the aquifer into deeper oxic zones. Given the persistence of nitrate in young oxic groundwater that was recharged several decades ago, and the lack of a confining unit, the downward movement of young contaminated water may result in higher nitrate concentrations over time in deeper parts of the aquifer containing older oxic water.

  12. Investigating river–aquifer relations using water temperature in an anthropized environment (Motril-Salobreña aquifer)

    DEFF Research Database (Denmark)

    Duque, Carlos; Calvache, Marie; Engesgaard, Peter Knudegaard

    2010-01-01

    . Temperature measurements in river, air, and a number of boreholes located at different distances away from the river were monitored over a 6 year period. Temperature is easy to monitor and especially useful in anthropized aquifers due to their natural and non-pollutant characteristics. The thermal responses...

  13. Potentiometric-surface altitude of the confined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  14. Water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  15. Geospatial compilation of historical water-level changes in the Chicot and Evangeline aquifers 1977-2013 and Jasper aquifer 2000-13, Gulf Coast aquifer system, Houston-Galveston region, Texas

    Science.gov (United States)

    Johnson, Michaela R.; Linard, Joshua I.

    2014-01-01

    The U.S. Geological Survey (USGS) in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District has produced an annual series of reports that depict water-level changes in the Chicot, Evangeline, and Jasper aquifers of the Gulf Coast aquifer system in the Houston-Galveston region, Texas, from 1977 to 2013. Changes are determined from water-level measurements between December and March of each year from groundwater wells screened in one of the three aquifers. Existing published maps and unpublished geographic information system (GIS) datasets were compiled into a comprehensive geodatabase of all water-level-change maps produced as part of this multiagency effort. Annual water-level-change maps were georeferenced and digitized where existing GIS data were unavailable (1979–99). Existing GIS data available for 2000–13 were included in the geodatabase. The compilation contains 121 datasets showing water-level changes for each primary aquifer of the Gulf Coast aquifer system: 56 for the Chicot aquifer (1977; 1979–2013 and 1990; 1993–2013), 56 for the Evangeline aquifer (1977; 1979–2013 and 1990; 1993–2013), and 9 for the Jasper aquifer (2000; 2005–13).

  16. Characterisation of hydraulic head changes and aquifer properties in the London Basin using Persistent Scatterer Interferometry ground motion data

    Science.gov (United States)

    Bonì, R.; Cigna, F.; Bricker, S.; Meisina, C.; McCormack, H.

    2016-09-01

    In this paper, Persistent Scatterer Interferometry was applied to ERS-1/2 and ENVISAT satellite data covering 1992-2000 and 2002-2010 respectively, to analyse the relationship between ground motion and hydraulic head changes in the London Basin, United Kingdom. The integration of observed groundwater levels provided by the Environment Agency and satellite-derived displacement time series allowed the estimation of the spatio-temporal variations of the Chalk aquifer storage coefficient and compressibility over an area of ∼1360 km2. The average storage coefficient of the aquifer reaches values of 1 × 10-3 and the estimated average aquifer compressibility is 7.7 × 10-10 Pa-1 and 1.2 × 10-9 Pa-1 for the periods 1992-2000 and 2002-2010, respectively. Derived storage coefficient values appear to be correlated with the hydrogeological setting, where confined by the London Clay the storage coefficient is typically an order of magnitude lower than where the chalk is overlain by the Lambeth Group. PSI-derived storage coefficient estimates agree with the values obtained from pumping tests in the same area. A simplified one-dimensional model is applied to simulate the ground motion response to hydraulic heads changes at nine piezometers. The comparison between simulated and satellite-observed ground motion changes reveals good agreement, with errors ranging between 1.4 and 6.9 mm, and being 3.2 mm on average.

  17. Confronting vicinity of the surface water and sea shore in a shallow glaciogenic aquifer in southern Finland

    Directory of Open Access Journals (Sweden)

    S. Luoma

    2014-07-01

    Full Text Available The chemical characterization of groundwater in shallow, unconfined, low-lying coastal aquifer in Santala, southern Finland was identified by utilising the integrations of multivariate statistical approaches; principal component analysis (PCA and hierarchical cluster analysis (HCA, with the stable isotope δ2H and δ18O, hydrogeochemistry and field monitoring data. HCA classified groundwater samples into 6 distinct groups that reveal the factors controlling temporal and spatial variations of groundwater geochemistry such as geology, anthropogenic sources from human activities, climate and surface water. High temporal variation of groundwater chemistry corresponds directly to precipitation. With increase in precipitation, KMnO4 consumption, EC, alkalinity and Ca concentrations also increase in most wells, while Fe, Al, Mn and SO4 are occasionally increased during spring after the snowmelt in specific geologic condition. The continued increase of NO3 and metals concentrations in groundwater indicates the potential contamination risk to aquifer. Stable isotopes of δ18O and δ2H indicate groundwater recharges directly from the meteoric water with insignificant contribution from lake water, and no seawater intrusion into the aquifer. Groundwater geochemistry suggests local seawater intrusion being temporary able to take place in the sulphate reduction zone along the fresh and seawater mixed zone in the low-lying coastal area but contribution of seawater was very low. The influence of lake water can be observed from the increases of KMnO4 consumption in wells nearby the lake.

  18. Evaluating uncertainty in predicting spatially variable representative elementary scales in fractured aquifers, with application to Turkey Creek Basin, Colorado

    Science.gov (United States)

    Wellman, Tristan P.; Poeter, Eileen P.

    2006-08-01

    Computational limitations and sparse field data often mandate use of continuum representation for modeling hydrologic processes in large-scale fractured aquifers. Selecting appropriate element size is of primary importance because continuum approximation is not valid for all scales. The traditional approach is to select elements by identifying a single representative elementary scale (RES) for the region of interest. Recent advances indicate RES may be spatially variable, prompting unanswered questions regarding the ability of sparse data to spatially resolve continuum equivalents in fractured aquifers. We address this uncertainty of estimating RES using two techniques. In one technique we employ data-conditioned realizations generated by sequential Gaussian simulation. For the other we develop a new approach using conditioned random walks and nonparametric bootstrapping (CRWN). We evaluate the effectiveness of each method under three fracture densities, three data sets, and two groups of RES analysis parameters. In sum, 18 separate RES analyses are evaluated, which indicate RES magnitudes may be reasonably bounded using uncertainty analysis, even for limited data sets and complex fracture structure. In addition, we conduct a field study to estimate RES magnitudes and resulting uncertainty for Turkey Creek Basin, a crystalline fractured rock aquifer located 30 km southwest of Denver, Colorado. Analyses indicate RES does not correlate to rock type or local relief in several instances but is generally lower within incised creek valleys and higher along mountain fronts. Results of this study suggest that (1) CRWN is an effective and computationally efficient method to estimate uncertainty, (2) RES predictions are well constrained using uncertainty analysis, and (3) for aquifers such as Turkey Creek Basin, spatial variability of RES is significant and complex.

  19. Reconstruction of the Friuli Venezia Giulia Plain aquifers

    Science.gov (United States)

    Calligaris, Chiara; Cimolino, Aurelie; Cucchi, Franco; Deana, Alberto; Treu, Francesco; Zini, Luca

    2010-05-01

    The constantly increasing of water demand for human consumptions has necessitated a reconstruction of the hydrogeologic characteristics and properties as well isotopic features of the aquifers of the Friuli Venezia Giulia Plain (FP). The DiSGAM and DICA have been engaged by the Hydraulic Survey of the FVG Region in order to coordinate an integrated study finalized to the FP confined and unconfined aquifer geometries reconstruction and to provide guide-lines for water rational exploitation (Agreement D.G.R. n. 1827 dd. 27.07.2007). The Friuli Venezia Giulia Plain, located in the northeastern sector of Italy, hosts well developed Plio-Quaternary unconfined and confined alluvial aquifers. The main surface drainage of the Plain is the Tagliamento River. The regional hydrogeological situation is characterized in the north by an extensive alluvial unconfined aquifer mostly contained in carbonate gravels. This area extends from the Pre-Alps to the resurgence belt. The resurgence belt is 2 to 8 km wide and 80 kilometres long. In this area the water table intersects the topographic surface forming numerous plain springs and rivers. The resurgence belt sets a geohydrological boundary between the Upper and Lower Friulian Plain. In this strip the unconfined aquifer changes into a multi-layered confined that reach a thickness of up to 500 m with a progressive increase in a westward direction towards the Adriatic Sea. In order to define underground aquifer relations and patterns, more than 1800 stratigraphic columns have been collected from different public departments water well database. Well logs have been georeferred, missing elevations calculated by regional DTM, possible correspondences controlled and datasets updated. In order to better correlate spatial data, an unique implemented lithostratigraphy legend has been created from present different ones; it is composed of: Lithological Entries (relating lithology and granulometric features; permeability linked different

  20. Aquifer/aquitard interfaces: mixing zones that enhance biogeochemical reactions

    Science.gov (United States)

    McMahon, P. B.

    2001-01-01

    Several important biogeochemical reactions are known to occur near the interface between aquifer and aquitard sediments. These reactions include O2 reduction; denitrification; and Fe3+, SO42-, and CO2 (methanogenesis) reduction. In some settings, these reactions occur on the aquitard side of the interface as electron acceptors move from the aquifer into the electron-donor-enriched aquitard. In other settings, these reactions occur on the aquifer side of the interface as electron donors move from the aquitard into the electron-acceptor-enriched, or microorganism-enriched, aquifer. Thus, the aquifer/aquitard interface represents a mixing zone capable of supporting greater microbial activity than either hydrogeologic unit alone. The extent to which biogeochemical reactions proceed in the mixing zone and the width of the mixing zone depend on several factors, including the abundance and solubility of electron acceptors and donors on either side of the interface and the rate at which electron acceptors and donors react and move across the interface. Biogeochemical reactions near the aquifer/aquitard interface can have a substantial influence on the chemistry of water in aquifers and on the chemistry of sediments near the interface. Résumé. Il se produit au voisinage de l'interface entre les aquifères et les imperméables plusieurs réactions biogéochimiques importantes. Il s'agit des réactions de réduction de l'oxygène, de la dénitrification et de la réduction de Fe3+, SO42- et CO2 (méthanogenèse). Dans certaines situations, ces réactions se produisent du côté imperméable de l'interface, avec des accepteurs d'électrons qui vont de l'aquifère vers l'imperméable riche en donneurs d'électrons. Dans d'autres situations, ces réactions se produisent du côté aquifère de l'interface, avec des donneurs d'électrons qui se déplacent de l'imperméable vers l'aquifère riche en accepteurs d'électrons ou en microorganismes. Ainsi, l'interface aquif

  1. Hydrogeology, ground-water movement, and subsurface storage in the Floridan aquifer system in southern Florida

    Science.gov (United States)

    Meyer, Frederick W.

    1989-01-01

    The Floridan aquifer system of southern Florida is composed chiefly of carbonate rocks that range in age from early Miocene to Paleocene. The top of the aquifer system in southern Florida generally is at depths ranging from 500 to 1,000 feet, and the average thickness is about 3,000 feet. It is divided into three general hydrogeologic units: (1) the Upper Floridan aquifer, (2) the middle confining unit, and (3) the Lower Floridan aquifer. The Upper Floridan aquifer contains brackish ground water, and the Lower Floridan aquifer contains salty ground water that compares chemically to modern seawater. Zones of high permeability are present in the Upper and Lower Floridan aquifers. A thick, cavernous dolostone in the Lower Floridan aquifer, called the Boulder Zone, is one of the most permeable carbonate units in the world (transmissivity of about 2.5 x 107 feet squared per day). Ground-water movement in the Upper Floridan aquifer is generally southward from the area of highest head in central Florida, eastward to the Straits of Florida, and westward to the Gulf of Mexico. Distributions of natural isotopes of carbon and uranium generally confirm hydraulic gradients in the Lower Floridan aquifer. Groundwater movement in the Lower Floridan aquifer is inland from the Straits of Florida. The concentration gradients of the carbon and uranium isotopes indicate that the source of cold saltwater in the Lower Floridan aquifer is seawater that has entered through the karat features on the submarine Miami Terrace near Fort Lauderdale. The relative ages of the saltwater suggest that the rate of inland movement is related in part to rising sea level during the Holocene transgression. Isotope, temperature, and salinity anomalies in waters from the Upper Floridan aquifer of southern Florida suggest upwelling of saltwater from the Lower Floridan aquifer. The results of the study support the hypothesis of circulating relatively modern seawater and cast doubt on the theory that the

  2. Modeling of groundwater flow for Mujib aquifer, Jordan

    Indian Academy of Sciences (India)

    Fayez Abdulla; Tamer Al-Assa’d

    2006-06-01

    Jordan is an arid country with very limited water resources.Groundwater is the main source for its water supply.Mujib aquifer is located in the central part of Jordan and is a major source of drinking water for Amman,Madaba and Karak cities.High abstraction rates from Mujib aquifer during the previous years lead to a major decline in water levels and deterioration in groundwater quality. Therefore,proper groundwater management of Mujib aquifer is necessary;and groundwater flow modeling is essential for proper management.For this purpose,Mod flow was used to build a groundwater flow model to simulate the behavior of the flow system under different stresses.The model was calibrated for steady state condition by matching observed and simulated initial head counter lines.Drawdown data for the period 1985-1995 were used to calibrate the transient model by matching simulated drawdown with the observed one.Then,the transient model was validated by using drawdown data for the period 1996-2002.The results of the calibrated model showed that the horizontal hydraulic conductivity of the B2/A7 aquifer ranges between 0.001 and 40 m/d. Calibrated speci fic yield ranges from 0.0001 to 0.15.The water balance for the steady state condition of Mujib aquifer indicated that the total annual direct recharge is 20.4 × 106 m3, the total annual in flow is 13.0 × 106 m3, springs discharge is 15.3 × 106 m3, and total annual out flow is 18.7 × 106 m3. Different scenarios were considered to predict aquifer system response under different conditions. The results of the sensitivity analysis show that the model is highly sensitive to horizontal hydraulic conductivity and anisotropy and with lower level to the recharge rates.Also the model is sensitive to specific yield.

  3. Arsenic attenuation by oxidized aquifer sediments in Bangladesh

    Science.gov (United States)

    Stollenwerk, K.G.; Breit, G.N.; Welch, A.H.; Yount, J.C.; Whitney, J.W.; Foster, A.L.; Uddin, M.N.; Majumder, R.K.; Ahmed, N.

    2007-01-01

    Recognition of arsenic (As) contamination of shallow fluvio-deltaic aquifers in the Bengal Basin has resulted in increasing exploitation of groundwater from deeper aquifers that generally contain low concentrations of dissolved As. Pumping-induced infiltration of high-As groundwater could eventually cause As concentrations in these aquifers to increase. This study investigates the adsorption capacity for As of sediment from a low-As aquifer near Dhaka, Bangladesh. A shallow, chemically-reducing aquifer at this site extends to a depth of 50??m and has maximum As concentrations in groundwater of 900????g/L. At depths greater than 50??m, geochemical conditions are more oxidizing and groundwater has < 5????g/L As. There is no thick layer of clay at this site to inhibit vertical transport of groundwater. Arsenite [As(III)] is the dominant oxidation state in contaminated groundwater; however, data from laboratory batch experiments show that As(III) is oxidized to arsenate [As(V)] by manganese (Mn) minerals that are present in the oxidized sediment. Thus, the long-term viability of the deeper aquifers as a source of water supply is likely to depend on As(V) adsorption. The adsorption capacity of these sediments is a function of the oxidation state of As and the concentration of other solutes that compete for adsorption sites. Arsenite that was not oxidized did adsorb, but to a much lesser extent than As(V). Phosphate (P) caused a substantial decrease in As(V) adsorption. Increasing pH and concentrations of silica (Si) had lesser effects on As(V) adsorption. The effect of bicarbonate (HCO3) on As(V) adsorption was negligible. Equilibrium constants for adsorption of As(V), As(III), P, Si, HCO3, and H were determined from the experimental data and a quantitative model developed. Oxidation of As(III) was modeled with a first-order rate constant. This model was used to successfully simulate As(V) adsorption in the presence of multiple competing solutes. Results from these

  4. Hydrogeologic characterization of the Brazos River Alluvium Aquifer, Bosque County to Fort Bend County, Texas

    Science.gov (United States)

    Shah, Sachin D.; Houston, Natalie A.; Braun, Christopher L.

    2007-01-01

    Introduction The Brazos River alluvium aquifer underlies the Brazos River in Texas from Bosque County to Fort Bend County. The aquifer, one of 21 minor aquifers in the State, supplies water for irrigation, domestic, stock, and commercial use. The Brazos River alluvium aquifer likely will become more important in the future as demand for water increases statewide. A thorough understanding of the hydrogeology of the alluvium aquifer will be the foundation for future studies in the area. During October 2006-April 2007, the U.S. Geological Survey, in cooperation with the Texas Water Development Board, conducted a study to delineate the altitude of the top, altitude of the base, and thickness of the Brazos River alluvium aquifer, and to compile and summarize available hydraulic property (specific capacity, transmissivity, and hydraulic conductivity) data. A digital elevation model was used as the altitude of the top of the aquifer. The altitude of the base of the aquifer was generated using data from wells. The study area encompasses the Brazos River alluvium aquifer in parts of Bosque, Hill, McLennan, Falls, Robertson, Milam, Brazos, Burleson, Grimes, Washington, Waller, Austin, and Fort Bend Counties and a 1.5-mile-wide lateral buffer adjacent to the aquifer. The results of this study will be used by the Texas Water Development Board for input into a ground-water availability model.

  5. Semi-analytical solutions for flow to a well in an unconfined-fractured aquifer system

    Science.gov (United States)

    Sedghi, Mohammad M.; Samani, Nozar

    2015-09-01

    Semi-analytical solutions of flow to a well in an unconfined single porosity aquifer underlain by a fractured double porosity aquifer, both of infinite radial extent, are obtained. The upper aquifer is pumped at a constant rate from a pumping well of infinitesimal radius. The solutions are obtained via Laplace and Hankel transforms and are then numerically inverted to time domain solutions using the de Hoog et al. algorithm and Gaussian quadrature. The results are presented in the form of dimensionless type curves. The solution takes into account the effects of pumping well partial penetration, water table with instantaneous drainage, leakage with storage in the lower aquifer into the upper aquifer, and storativity and hydraulic conductivity of both fractures and matrix blocks. Both spheres and slab-shaped matrix blocks are considered. The effects of the underlying fractured aquifer hydraulic parameters on the dimensionless drawdown produced by the pumping well in the overlying unconfined aquifer are examined. The presented solution can be used to estimate hydraulic parameters of the unconfined and the underlying fractured aquifer by type curve matching techniques or with automated optimization algorithms. Errors arising from ignoring the underlying fractured aquifer in the drawdown distribution in the unconfined aquifer are also investigated.

  6. Hydrochemical and geoelectrical investigation of the coastal shallow aquifers in El-Omayed area, Egypt.

    Science.gov (United States)

    Atwia, M G; Masoud, A A

    2013-08-01

    Monitoring and assessment of the coastal aquifers are becoming a worldwide concern for the need of additional and sustainable water resources to satisfy demographic growth and economic development. A hydrochemical and geoelectrical investigation was conducted in the El-Omayed area in the northwestern coast of Egypt. The aim of the study was to delineate different water-bearing formations, provide a general evaluation of groundwater quality, and identify the recharge sources in aquifers. Thirty-seven water samples were collected and chemically analyzed from the sand dune accumulations and oolitic limestone aquifers. Fifteen profiles of vertical electrical soundings (VESs) were obtained in the oolitic limestone aquifer to examine the variations of subsurface geology and associated groundwater chemistry. The groundwater reserves in the El-Omayed area are mainly contained in sand dune accumulations and oolitic limestone aquifers. The aquifer of sand dune accumulations contains freshwater of low salinity (average total dissolved solids (TDS) = 974 mg/l). Groundwater of oolitic limestone aquifer is slightly brackish (average TDS = 1,486 mg/l). Groundwater of these aquifers can be used for irrigation under special management for salinity control, and regular leaching as indicated by electrical conductivity and sodium adsorption ratio. Results of VES interpretation classified the subsurface sequence of oolitic limestone aquifer into four geoelectric zones, with increasing depth, calcareous loam, gypsum, oolitic limestone, and sandy limestone. Oolitic limestone constitutes the main aquifer and has a thickness of 12-32 m.

  7. Hydrogeological typologies of the Indo-Gangetic basin alluvial aquifer, South Asia

    Science.gov (United States)

    Bonsor, H. C.; MacDonald, A. M.; Ahmed, K. M.; Burgess, W. G.; Basharat, M.; Calow, R. C.; Dixit, A.; Foster, S. S. D.; Gopal, K.; Lapworth, D. J.; Moench, M.; Mukherjee, A.; Rao, M. S.; Shamsudduha, M.; Smith, L.; Taylor, R. G.; Tucker, J.; van Steenbergen, F.; Yadav, S. K.; Zahid, A.

    2017-02-01

    The Indo-Gangetic aquifer is one of the world's most important transboundary water resources, and the most heavily exploited aquifer in the world. To better understand the aquifer system, typologies have been characterized for the aquifer, which integrate existing datasets across the Indo-Gangetic catchment basin at a transboundary scale for the first time, and provide an alternative conceptualization of this aquifer system. Traditionally considered and mapped as a single homogenous aquifer of comparable aquifer properties and groundwater resource at a transboundary scale, the typologies illuminate significant spatial differences in recharge, permeability, storage, and groundwater chemistry across the aquifer system at this transboundary scale. These changes are shown to be systematic, concurrent with large-scale changes in sedimentology of the Pleistocene and Holocene alluvial aquifer, climate, and recent irrigation practices. Seven typologies of the aquifer are presented, each having a distinct set of challenges and opportunities for groundwater development and a different resilience to abstraction and climate change. The seven typologies are: (1) the piedmont margin, (2) the Upper Indus and Upper-Mid Ganges, (3) the Lower Ganges and Mid Brahmaputra, (4) the fluvially influenced deltaic area of the Bengal Basin, (5) the Middle Indus and Upper Ganges, (6) the Lower Indus, and (7) the marine-influenced deltaic areas.

  8. Hydrogeological typologies of the Indo-Gangetic basin alluvial aquifer, South Asia

    Science.gov (United States)

    Bonsor, H. C.; MacDonald, A. M.; Ahmed, K. M.; Burgess, W. G.; Basharat, M.; Calow, R. C.; Dixit, A.; Foster, S. S. D.; Gopal, K.; Lapworth, D. J.; Moench, M.; Mukherjee, A.; Rao, M. S.; Shamsudduha, M.; Smith, L.; Taylor, R. G.; Tucker, J.; van Steenbergen, F.; Yadav, S. K.; Zahid, A.

    2017-08-01

    The Indo-Gangetic aquifer is one of the world's most important transboundary water resources, and the most heavily exploited aquifer in the world. To better understand the aquifer system, typologies have been characterized for the aquifer, which integrate existing datasets across the Indo-Gangetic catchment basin at a transboundary scale for the first time, and provide an alternative conceptualization of this aquifer system. Traditionally considered and mapped as a single homogenous aquifer of comparable aquifer properties and groundwater resource at a transboundary scale, the typologies illuminate significant spatial differences in recharge, permeability, storage, and groundwater chemistry across the aquifer system at this transboundary scale. These changes are shown to be systematic, concurrent with large-scale changes in sedimentology of the Pleistocene and Holocene alluvial aquifer, climate, and recent irrigation practices. Seven typologies of the aquifer are presented, each having a distinct set of challenges and opportunities for groundwater development and a different resilience to abstraction and climate change. The seven typologies are: (1) the piedmont margin, (2) the Upper Indus and Upper-Mid Ganges, (3) the Lower Ganges and Mid Brahmaputra, (4) the fluvially influenced deltaic area of the Bengal Basin, (5) the Middle Indus and Upper Ganges, (6) the Lower Indus, and (7) the marine-influenced deltaic areas.

  9. Movement of coliform bacteria and nutrients in ground water flowing through basalt and sand aquifers.

    Science.gov (United States)

    Entry, J A; Farmer, N

    2001-01-01

    Large-scale deposition of animal manure can result in contamination of surface and ground water and in potential transfer of disease-causing enteric bacteria to animals or humans. We measured total coliform bacteria (TC), fecal coliform bacteria (FC), NO3, NH4, total P, and PO4 in ground water flowing from basalt and sand aquifers, in wells into basalt and sand aquifers, in irrigation water, and in river water. Samples were collected monthly for 1 yr. Total coliform and FC numbers were always higher in irrigation water than in ground water, indicating that soil and sediment filtered most of these bacteria before they entered the aquifers. Total coliform and FC numbers in ground water were generally higher in the faster flowing basalt aquifer than in the sand aquifer, indicating that the slower flow and finer grain size may filter more TC and FC bacteria from water. At least one coliform bacterium/100 mL of water was found in ground water from both basalt and sand aquifers, indicating that ground water pumped from these aquifers is not necessarily safe for human consumption according to the American Public Health Association and the USEPA. The NO3 concentrations were usually higher in water flowing from the sand aquifer than in water flowing from the basalt aquifer or in perched water tables in the basalt aquifer. The PO4 concentrations were usually higher in water flowing from the basalt aquifer than in water flowing from the sand aquifer. The main concern is fecal contamination of these aquifers and health consequences that may arise from human consumption.

  10. Fraction of young water as an indicator of aquifer vulnerability along two regional flow paths in the Mississippi embayment aquifer system, southeastern USA

    Science.gov (United States)

    Kingsbury, James A.; Barlow, Jeannie R. B.; Jurgens, Bryant C.; McMahon, Peter B.; Carmichael, John K.

    2017-09-01

    Wells along two regional flow paths were sampled to characterize changes in water quality and the vulnerability to contamination of the Memphis aquifer across a range of hydrologic and land-use conditions in the southeastern United States. The flow paths begin in the aquifer outcrop area and end at public supply wells in the confined parts of the aquifer at Memphis, Tennessee. Age-date tracer (e.g. SF6, 3H, 14C) data indicate that a component of young water is present in the aquifer at most locations along both flow paths, which is consistent with previous studies at Memphis that documented leakage of shallow water into the Memphis aquifer locally where the overlying confining unit is thin or absent. Mixtures of young and old water were most prevalent where long-term pumping for public supply has lowered groundwater levels and induced downward movement of young water. The occurrence of nitrate, chloride and synthetic organic compounds was correlated to the fraction of young water along the flow paths. Oxic conditions persisted for 10 km or more down dip of the confining unit, and the presence of young water in confined parts of the aquifer suggest that contaminants such as nitrate-N have the potential for transport. Long-term monitoring data for one of the flow-path wells screened in the confined part of the aquifer suggest that the vulnerability of the aquifer as indicated by the fraction of young water is increasing over time.

  11. Regeneration of a confined aquifer after redevelopment and decommission of artesian wells, example from Grafendorf aquifer (Styria, Austria)

    Science.gov (United States)

    Mehmedovski, Nudzejma; Winkler, Gerfried

    2016-04-01

    Water is essential for life and it is therefore necessary to protect drinking water sustainably. Compared to shallow groundwater, deeper groundwater is especially important due to its characteristic tendency to remain extensively unaffected by environmental impacts. Thus, the uncontrolled waste of this valuable resource has to be avoided. A lot of artesian wells have been established in Grafendorf bei Hartberg (Styria, Austria). Almost all wells were not state-of-the art. As a result the different aquifer horizons began to intermix. Additionally some of the artesian wells had a permanent free overflow and the water was not even used. Consequently, since 1950, where the mean discharge of 37 wells was 0,334 l/s per well, the discharge has decreased to 0,090 l/s until 2013, which means a decline of about 75 %. As a reaction to these declines a decommissioning campaign was conducted where 69 artesian wells have been closed by injecting a cement-bentonite suspension (ratio 3:1). The Grafendorf aquifer is situated in the Styrian Basin and consists of 5 separated artesian horizons in Neogene sediments. These artesian horizons range from 42 m (1st horizon) to 176 m (5th horizon) and mostly consist of sand, partly of fine/medium/coarse gravel and partially with minor clay content. In order to analyse the reaction of the Grafendorf aquifer to these redevelopments, 5 monitoring wells could be used for the analysis. Some monitoring wells include different aquifer horizons and hydraulically short cut them. Thus, in this work the analysis focus on the general trend of the whole aquifer system neglecting the individual interactions between the different aquifers. In a first investigation step the hydraulic properties of the aquifer system has been determined using pumping tests which were analysed with different analytical solutions with the software AQTESOLV. Overall the pumping test solutions hardly differ in the transmissivity and hydraulic conductivity. On the contrary the

  12. Multi-scale approach for 3D hydrostratigraphic and groundwater flow modelling of Milan (Northern Italy) urban aquifers.

    Science.gov (United States)

    De Caro, Mattia; Crosta, Giovanni; Frattini, Paolo; Perico, Roberta

    2017-04-01

    During the last century, urban groundwater was heavily exploited for public and industrial supply. As the water demands of industry have fallen, many cities are now experiencing rising groundwater levels with consequent concerns about localized flooding of basements, reduction of soil bearing capacities under foundations, soil internal erosion and the mobilization of contaminants. The city of Milan (Northern Italy) draws water for domestic and industrial purposes from aquifers beneath the urban area. The rate of abstraction has been varying during the last century, depending upon the number of inhabitants and the development of industrial activities. The groundwater abstraction raised to a maximum of about 350x106 m3/yr in the middle 1970s and has successively decreased to a value of about 230x106 m3/yr at present days. This caused a water table raise at an average rate of about 1 m/yr inducing infiltrations and flooding of deep constructions (e.g. building foundations and basements, underground subway excavations). Starting from a large hydrostratigraphic database (8628 borehole logs), a multi-scale approach for the reconstruction of the aquifers geometry (unconfined and semi-confined) at regional-scale has been used. First, a three-level hierarchical classification of the lithologies (lithofacies, hydrofacies, aquifer groups) has been adopted. Then, the interpretation of several 2D cross-sections was attained with Target for ArcGIS exploration software. The interpretation of cross-sections was based on the characteristics of depositional environments of the analysed aquifers (from meandering plain to proximal outwash deposits), on the position of quaternary deposits, and on the distribution of geochemical parameters (i.e. indicator contaminants and major ions). Finally, the aquifer boundary surfaces were interpolated with standard algorithms. The hydraulic properties of analysed aquifers were estimated through the analyses of available step-drawdown tests (Theis

  13. Hydrogeochemical features of groundwater of semi-confined coastal aquifer in Amol-Ghaemshahr plain, Mazandaran Province, Northern Iran.

    Science.gov (United States)

    Khairy, Houshang; Janardhana, M R

    2013-11-01

    Hydrogeochemical data of groundwater from the semi-confined aquifer of a coastal two-tier aquifer in Amol-Ghaemshahr plain, Mazandaran Province, Northern Iran reveal salinization of the fresh groundwater (FGW). The saline groundwater zone is oriented at an angle to both Caspian Sea coastline and groundwater flow direction and extends inland from the coastline for more than 40 km. Spearman's rank correlation coefficient matrices, factor analysis data, and values of C ratio, chloro-alkaline indices, and Na(+)/Cl(-) molar ratio indicate that the ionic load in the FGW is derived essentially from carbonic acid-aided weathering of carbonates and aluminosilicate minerals, relict connate saline water, and ion exchange reactions. Saline groundwater samples (SGWS) (n = 20) can be classified into two groups. SGWS of group 1 (n = 17) represent the saline groundwater zone below the Caspian Sea level, and salinization is attributed essentially to (1) lateral intrusion of Caspian seawater as a consequence of (a) excessive withdrawal of groundwater from closely spaced bore wells located in the eastern part of the coastal zone and (b) imbalance between recharge and discharge of the two-tier aquifer and (2) upconing of paleobrine (interfaced with FGW) along deep wells. SGWS of this group contain, on average, 7.9% of saltwater, the composition of which is similar to that of Caspian seawater. SGWS of group 2 (n = 3) belong to the saline groundwater zone encountered above the Caspian Sea level, and salinization of the groundwater representing these samples is attributed to irrigation return flow (n = 2) and inflow of saline river water (n = 1).

  14. Geochemistry of the Cambrian-Ordovician aquifer system in the northern Midwest, United States: D in Regional aquifer-system analysis

    Science.gov (United States)

    Siegel, D.I.

    1989-01-01

    Distributions of solutes in aquifers of Cambrian and Ordovician age were studied in Minnesota, Wisconsin, Iowa, Illinois, northwestern Indiana, and northern Missouri to determine the sources of solutes and the probable chemical mechanisms that control regional variations in water quality. This work is part of the Northern Midwest Regional Aquifer-System Analysis project, whose objective is to describe and model the regional hydrogeology of the Cambrian- Ordovician aquifer system in the study region. The data base used included more than 3,000 ground-water-quality analyses from all major aquifers, but especially from the St. Peter, Jordan, and Mount Simon Sandstones and their equivalents. Regional variations in the water chemistry of glacial drift and other sedimentary units that overlie the Cambrian-Ordovician aquifer system in recharge areas in Minnesota, Iowa, Wisconsin, and Illinois were also studied, but to a lesser degree.

  15. Groundwater quality assessment of the Limnos Island Volcanic Aquifers, Greece.

    Science.gov (United States)

    Panagopoulos, George; Panagiotaras, Dionisios; Giannoulopoulos, Panagiotis

    2013-05-01

    Limnos Island in Greece, which has been the subject of extensive hydrogeological research, contains confined volcanic aquifers that overlie impermeable flysch. Groundwater salinization is usually the effect of seawater intrusion, and results from a combination of factors such as low annual areal precipitation and exploitation of aquifers for civil, commercial, and agricultural purposes. Areas with intense agricultural activities have also increasingly observed these effects. A geochemical evaluation on the basis of multiple ion (Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO4(2-), NO3-) concentrations and physicochemical parameters distribution revealed that ion exchange is the dominant hydrogeochemical process. However, the enrichment of groundwater in potassium and magnesium results from rock and mineral weathering and dissolution.

  16. Geochemical detection of carbon dioxide in dilute aquifers

    Directory of Open Access Journals (Sweden)

    Aines Roger

    2009-03-01

    Full Text Available Abstract Background Carbon storage in deep saline reservoirs has the potential to lower the amount of CO2 emitted to the atmosphere and to mitigate global warming. Leakage back to the atmosphere through abandoned wells and along faults would reduce the efficiency of carbon storage, possibly leading to health and ecological hazards at the ground surface, and possibly impacting water quality of near-surface dilute aquifers. We use static equilibrium and reactive transport simulations to test the hypothesis that perturbations in water chemistry associated with a CO2 gas leak into dilute groundwater are important measures for the potential release of CO2 to the atmosphere. Simulation parameters are constrained by groundwater chemistry, flow, and lithology from the High Plains aquifer. The High Plains aquifer is used to represent a typical sedimentary aquifer overlying a deep CO2 storage reservoir. Specifically, we address the relationships between CO2 flux, groundwater flow, detection time and distance. The CO2 flux ranges from 103 to 2 × 106 t/yr (0.63 to 1250 t/m2/yr to assess chemical perturbations resulting from relatively small leaks that may compromise long-term storage, water quality, and surface ecology, and larger leaks characteristic of short-term well failure. Results For the scenarios we studied, our simulations show pH and carbonate chemistry are good indicators for leakage of stored CO2 into an overlying aquifer because elevated CO2 yields a more acid pH than the ambient groundwater. CO2 leakage into a dilute groundwater creates a slightly acid plume that can be detected at some distance from the leak source due to groundwater flow and CO2 buoyancy. pH breakthrough curves demonstrate that CO2 leaks can be easily detected for CO2 flux ≥ 104 t/yr within a 15-month time period at a monitoring well screened within a permeable layer 500 m downstream from the vertical gas trace. At lower flux rates, the CO2 dissolves in the aqueous phase

  17. Multilayered aquifer modeling in the coastal sedimentary basin of Togo

    Science.gov (United States)

    Gnazou, M. D. T.; Sabi, B. E.; Lavalade, J. L.; Schwartz, J.; Akakpo, W.; Tozo, A.

    2017-01-01

    This work is a follow up to the hydrogeological synthesis done in 2012 on the coastal sedimentary basin of Togo. That synthesis notably emphasized the lack of piezometric monitoring in the last thirty years. This has kept us from learning about the dynamics and evolution of the resource in the context of rapidly increasing demand. We are therefore presenting a model for understanding flows, and its main objectives are to provide an initial management tool that should evolve with time as new data (piezometric monitoring, pumping tests, etc.) become available, and to determine what new information can be obtained that will help policy makers to manage the resource better. The results of steady state flow calibration have shown that the aquifer of the Continental Terminal overexploited in the West, can still be exploited in the East of the basin, the Maastrichtian on the whole basin. On the other hand, exploitation of Paleocene aquifers should be done with care.

  18. Fluoride in weathered rock aquifers of southern India: Managed Aquifer Recharge for mitigation.

    Science.gov (United States)

    Brindha, K; Jagadeshan, G; Kalpana, L; Elango, L

    2016-05-01

    Climatic condition, geology, and geochemical processes in an area play a major role on groundwater quality. Impact of these on the fluoride content of groundwater was studied in three regions-part of Nalgonda district in Telangana, Pambar River basin, and Vaniyar River basin in Tamil Nadu, southern India, which experience semi-arid climate and are predominantly made of Precambrian rocks. High concentration of fluoride in groundwater above 4 mg/l was recorded. Human exposure dose for fluoride through groundwater was higher in Nalgonda than the other areas. With evaporation and rainfall being one of the major contributors for high fluoride apart from the weathering of fluoride rich minerals from rocks, the effect of increase in groundwater level on fluoride concentration was studied. This study reveals that groundwater in shallow environment of all three regions shows dilution effect due to rainfall recharge. Suitable managed aquifer recharge (MAR) methods can be adopted to dilute the fluoride rich groundwater in such regions which is explained with two case studies. However, in deep groundwater, increase in fluoride concentration with increase in groundwater level due to leaching of fluoride rich salts from the unsaturated zone was observed. Occurrence of fluoride above 1.5 mg/l was more in areas with deeper groundwater environment. Hence, practicing MAR in these regions will increase the fluoride content in groundwater and so physical or chemical treatment has to be adopted. This study brought out the fact that MAR cannot be practiced in all regions for dilution of ions in groundwater and that it is essential to analyze the fluctuation in groundwater level and the fluoride content before suggesting it as a suitable solution. Also, this study emphasizes that long-term monitoring of these factors is an important criterion for choosing the recharge areas.

  19. Characterization of an alluvial aquifer with thermal tracer tomography

    Science.gov (United States)

    Somogyvári, Márk; Bayer, Peter

    2017-04-01

    In the summer of 2015, a series of thermal tracer tests was performed at the Widen field site in northeast Switzerland. At this site numerous hydraulic, tracer, geophysical and hydrogeophysical field tests have been conducted in the past to investigate a shallow alluvial aquifer. The goals of the campaign in 2015 were to design a cost-effective thermal tracer tomography setup and to validate the concept of travel time-based thermal tracer tomography under field conditions. Thermal tracer tomography uses repeated thermal tracer injections with different injection depths and distributed temperature measurements to map the hydraulic conductivity distribution of a heterogeneous aquifer. The tracer application was designed with minimal experimental time and cost. Water was heated in inflatable swimming pools using direct sunlight of the warm summer days, and it was injected as low temperature pulses in a well. Because of the small amount of injected heat, no long recovery times were required between the repeated heat tracer injections and every test started from natural thermal conditions. At Widen, four thermal tracer tests were performed during a period of three days. Temperatures were measured in one downgradient well using a distributed temperature measurement system installed at seven depth points. Totally 12 temperature breakthrough curves were collected. Travel time based tomographic inversion assumes that thermal transport is dominated by advection and the travel time of the thermal tracer can be related to the hydraulic conductivities of the aquifer. This assumption is valid in many shallow porous aquifers where the groundwater flow is fast. In our application, the travel time problem was treated by a tomographic solver, analogous to seismic tomography, to derive the hydraulic conductivity distribution. At the test site, a two-dimensional cross-well hydraulic conductivity profile was reconstructed with the travel time based inversion. The reconstructed profile

  20. Simulations of CO2 injection in saline aquifer formations

    OpenAIRE

    Lågeide, Lars Andreas

    2009-01-01

    This thesis is devoted to studies of long term storage of carbon dioxide in geological formations such as saline aquifers. The goal of the thesis is to contribute to the development of a totally integrated storage evaluation tool which considers reactive transport as well as geomechanics. Our secondary goal was to investigate the effects of introducing a fracture in the confining cap rock with respect to the mechanical and chemical aspects of gas injections. In order to safely assume that...

  1. Hydrogeophysical methods for analyzing aquifer storage and recovery systems.

    Science.gov (United States)

    Minsley, Burke J; Ajo-Franklin, Jonathan; Mukhopadhyay, Amitabha; Morgan, Frank Dale

    2011-01-01

    Hydrogeophysical methods are presented that support the siting and monitoring of aquifer storage and recovery (ASR) systems. These methods are presented as numerical simulations in the context of a proposed ASR experiment in Kuwait, although the techniques are applicable to numerous ASR projects. Bulk geophysical properties are calculated directly from ASR flow and solute transport simulations using standard petrophysical relationships and are used to simulate the dynamic geophysical response to ASR. This strategy provides a quantitative framework for determining site-specific geophysical methods and data acquisition geometries that can provide the most useful information about the ASR implementation. An axisymmetric, coupled fluid flow and solute transport model simulates injection, storage, and withdrawal of fresh water (salinity ∼500 ppm) into the Dammam aquifer, a tertiary carbonate formation with native salinity approximately 6000 ppm. Sensitivity of the flow simulations to the correlation length of aquifer heterogeneity, aquifer dispersivity, and hydraulic permeability of the confining layer are investigated. The geophysical response using electrical resistivity, time-domain electromagnetic (TEM), and seismic methods is computed at regular intervals during the ASR simulation to investigate the sensitivity of these different techniques to changes in subsurface properties. For the electrical and electromagnetic methods, fluid electric conductivity is derived from the modeled salinity and is combined with an assumed porosity model to compute a bulk electrical resistivity structure. The seismic response is computed from the porosity model and changes in effective stress due to fluid pressure variations during injection/recovery, while changes in fluid properties are introduced through Gassmann fluid substitution.

  2. Aquifer test interpretation using derivative analysis and diagnostic plots

    Science.gov (United States)

    Hernández-Espriú, Antonio; Real-Rangel, Roberto; Cortés-Salazar, Iván; Castro-Herrera, Israel; Luna-Izazaga, Gabriela; Sánchez-León, Emilio

    2017-04-01

    Pumping tests remain a method of choice to deduce fundamental aquifer properties and to assess well condition. In the oil and gas (O&G) industry, well testing has been the core technique in examining reservoir behavior over the last 50 years. The pressure derivative by Bourdet, it is perhaps, the most significant single development in the history of well test analysis. Recently, the so-called diagnostics plots (e.g. drawdown and drawdown derivative in a log-log plot) have been successfully tested in aquifers. However, this procedure is still underutilized by groundwater professionals. This research illustrates the applicability range, advantages and drawbacks (e.g. smoothing procedures) of diagnostic plots using field examples from a wide spectrum of tests (short/long tests, constant/variable flow rates, drawdown/buildup stages, pumping well/observation well) in dissimilar geological conditions. We analyze new and pre-existent aquifer tests in Mexico, USA, Canada, Germany, France and Saudi Arabia. In constant flow rate tests, our results show that derivative analysis is an easy, robust and powerful tool to assess near-borehole damage effects, formation heterogeneity, boundaries, flow regimes, infinite-acting radial stages, i.e., valid Theisian framework, and fracture-driven flow. In step tests, the effectiveness relies on high-frequency drawdown measurements. Moreover, we adapt O&G analytical solutions to cater for the conditions in groundwater systems. In this context, further parameters can be computed analytically from the plots, such as skin factor, head losses, wellbore storage, distance to the boundary, channel-aquifer and/or fracture zone width, among others. Therefore, diagnostic plots should be considered a mandatory tool for pumping tests analysis among hydrogeologists. This project has been supported by DGAPA (UNAM) under the research project PAPIIT IN-112815.

  3. Final policy toward owners of property containing contaminated aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Kandell, E.

    1995-05-24

    The policy states the agency`s position that, subject to certain conditions, where hazardous substances have come to be located on or in a property solely as the result of subsurface migration in an aquifer from a source or sources outside the property. EPA will not take enforcement actions under CERCLA, 42 U.S.C. 106 and 107 against the owner of such property to require the performance of response actions or the payment of response costs.

  4. Detection of Euryarchaeota and Crenarchaeota in an oxic basalt aquifer.

    Science.gov (United States)

    O'Connell, Seán P; Lehman, R Michael; Snoeyenbos-West, Oona; Winston, Vern D; Cummings, David E; Watwood, Mary E; Colwell, Frederick S

    2003-05-01

    Groundwater from an oxic, fractured basalt aquifer was examined for the presence of Archaea. DNA was extracted from cells concentrated from groundwater collected from five wells penetrating the eastern Snake River Plain Aquifer (Idaho, USA). Polymerase chain reaction (PCR) amplification of 16S rDNA was performed with Archaea-specific primers using both nested (ca. 200-bp product) and direct (ca. 600-bp product) PCR approaches. Estimates of the archaeal diversity were made by separating PCR products from all five wells by denaturing gradient gel electrophoresis (DGGE) and phylogenetic analysis of partial 16S rDNA sequences from two wells was performed following cloning procedures. Archaea were detected in all wells and the number of DGGE bands per well ranged from two to nine and varied according to PCR approach. There were 30 unique clonal 16S rDNA partial sequences (ca. 600 bp) within a total of 100 clones that were screened from two wells. Twenty-two of the 16S rDNA fragments recovered from the aquifer were related to the Crenarchaeota and Euryarchaeota kingdoms (one large clade of clones in the former and six smaller clades in the latter), with sequences ranging from 23.7 to 95.4% similar to those found in other investigations. The presence of potentially thermophilic or methanogenic Archaea in this fully oxic aquifer may be related to deep thermal sources or elevated dissolved methane concentrations. Many sequences were similar to those that represent non-thermophilic Crenarchaeota of which there are no known cultured members and therefore no putative function.

  5. Nitrate in the Columbia Aquifer, central Delmarva Peninsula, Maryland

    Science.gov (United States)

    Bachman, L.J.

    1984-01-01

    A study of nitrate in water from 604 wells tapping the Columbia aquifer on the Delmarva Peninsula in eastern Maryland describes the factors that affect nitrate variability. Samples were collected from 196 randomly selected wells and analyzed for nitrogen species. Many were also analyzed for major ions. In addition, results of 313 nitrate analyses were randomly selected from county health department files. About 95 analyses of water samples collected from 1945 to 1978 were also evaluated. The frequency distribution of the nitrate analyses is bimodal, with 25 percent of the sample ranging from 0 to about 0.42 milligrams per liter (mg/L) nitrate as nitrogen (N), and the median is about 0.1 mg/L; the rest ranges from 0.42 to 58 mg/L, and the median is about 5.9 mg/L. The overall median nitrate concentration is about 3.5 mg/L as N. Over half of the samples had nitrate concentrations of 3 mg/L as N or higher, indicating that the water in the aquifer has been affected by human activity. Nitrate-nitrogen concentrations exceeded the water-quality standard of 10 mg/L in 15 percent of the samples established by the U.S. Environmental Protection Agency. The major factors affecting nitrate concentration are the presence of a nitrogen source, hydrogeological conditions, and the soil drainage. Sites with poorly drained soils may have a lower nitrate concentration either because the soils block the entrance of nitrate into the aquifer or because the aquifer under a poorly drained soil is associated with a chemical environment that promotes denitrification. (USGS)

  6. Hydrogeophysical methods for analyzing aquifer storage and recovery systems

    Energy Technology Data Exchange (ETDEWEB)

    Minsley, B.J.; Ajo-Franklin, J.; Mukhopadhyay, A.; Morgan, F.D.

    2009-12-01

    Hydrogeophysical methods are presented that support the siting and monitoring of aquifer storage and recovery (ASR) systems. These methods are presented as numerical simulations in the context of a proposed ASR experiment in Kuwait, although the techniques are applicable to numerous ASR projects. Bulk geophysical properties are calculated directly from ASR flow and solute transport simulations using standard petrophysical relationships and are used to simulate the dynamic geophysical response to ASR. This strategy provides a quantitative framework for determining site-specific geophysical methods and data acquisition geometries that can provide the most useful information about the ASR implementation. An axisymmetric, coupled fluid flow and solute transport model simulates injection, storage, and withdrawal of fresh water (salinity {approx}500 ppm) into the Dammam aquifer, a tertiary carbonate formation with native salinity approximately 6000 ppm. Sensitivity of the flow simulations to the correlation length of aquifer heterogeneity, aquifer dispersivity, and hydraulic permeability of the confining layer are investigated. The geophysical response using electrical resistivity, time-domain electromagnetic (TEM), and seismic methods is computed at regular intervals during the ASR simulation to investigate the sensitivity of these different techniques to changes in subsurface properties. For the electrical and electromagnetic methods, fluid electric conductivity is derived from the modeled salinity and is combined with an assumed porosity model to compute a bulk electrical resistivity structure. The seismic response is computed from the porosity model and changes in effective stress due to fluid pressure variations during injection/recovery, while changes in fluid properties are introduced through Gassmann fluid substitution.

  7. Group X

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Susannah

    2007-08-16

    This project is currently under contract for research through the Department of Homeland Security until 2011. The group I was responsible for studying has to remain confidential so as not to affect the current project. All dates, reference links and authors, and other distinguishing characteristics of the original group have been removed from this report. All references to the name of this group or the individual splinter groups has been changed to 'Group X'. I have been collecting texts from a variety of sources intended for the use of recruiting and radicalizing members for Group X splinter groups for the purpose of researching the motivation and intent of leaders of those groups and their influence over the likelihood of group radicalization. This work included visiting many Group X websites to find information on splinter group leaders and finding their statements to new and old members. This proved difficult because the splinter groups of Group X are united in beliefs, but differ in public opinion. They are eager to tear each other down, prove their superiority, and yet remain anonymous. After a few weeks of intense searching, a list of eight recruiting texts and eight radicalizing texts from a variety of Group X leaders were compiled.

  8. Geospatial compilation of historical water-level altitudes in the Chicot and Evangeline aquifers 1977-2013 and Jasper aquifer 2000-13 in the Gulf Coast aquifer system, Houston-Galveston Region, Texas

    Science.gov (United States)

    Johnson, Michaela R.; Ellis, Robert H.H.

    2013-01-01

    The U.S. Geological Survey (USGS) in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District has produced a series of annual reports depicting groundwater-level altitudes in the Chicot, Evangeline, and Jasper aquifers of the Gulf Coast aquifer system in the Houston-Galveston region, Texas. To produce these annual reports, contours of equal water-level altitudes are created from water levels measured between December and March of each year from groundwater wells screened completely within one of these three aquifers. Information obtained from maps published in the annual series of USGS reports and geospatial datasets of water-level altitude contours used to create the annual series of USGS reports were compiled into a comprehensive geodatabase. The geospatial compilation contains 88 datasets from previously published contour maps showing water-level altitudes for each primary aquifer of the Gulf Coast aquifer system, 37 for the Chicot (1977–2013), 37 for the Evangeline aquifer (1977–2013), and 14 for the Jasper aquifer (2000–13).

  9. Relationship of regional water quality to aquifer thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.

    1983-11-01

    Ground-water quality and associated geologic characteristics may affect the feasibility of aquifer thermal energy storage (ATES) system development in any hydrologic region. This study sought to determine the relationship between ground-water quality parameters and the regional potential for ATES system development. Information was collected from available literature to identify chemical and physical mechanisms that could adversely affect an ATES system. Appropriate beneficiation techniques to counter these potential geochemical and lithologic problems were also identified through the literature search. Regional hydrology summaries and other sources were used in reviewing aquifers of 19 drainage regions in the US to determine generic geochemical characteristics for analysis. Numerical modeling techniques were used to perform geochemical analyses of water quality from 67 selected aquifers. Candidate water resources regions were then identified for exploration and development of ATES. This study identified six principal mechanisms by which ATES reservoir permeability may be impaired: (1) particulate plugging, (2) chemical precipitation, (3) liquid-solid reactions, (4) formation disaggregation, (5) oxidation reactions, and (6) biological activity. Specific proven countermeasures to reduce or eliminate these effects were found. Of the hydrologic regions reviewed, 10 were identified as having the characteristics necessary for ATES development: (1) Mid-Atlantic, (2) South-Atlantic Gulf, (3) Ohio, (4) Upper Mississippi, (5) Lower Mississippi, (6) Souris-Red-Rainy, (7) Missouri Basin, (8) Arkansas-White-Red, (9) Texas-Gulf, and (10) California.

  10. Boundary condition effects on maximum groundwater withdrawal in coastal aquifers.

    Science.gov (United States)

    Lu, Chunhui; Chen, Yiming; Luo, Jian

    2012-01-01

    Prevention of sea water intrusion in coastal aquifers subject to groundwater withdrawal requires optimization of well pumping rates to maximize the water supply while avoiding sea water intrusion. Boundary conditions and the aquifer domain size have significant influences on simulating flow and concentration fields and estimating maximum pumping rates. In this study, an analytical solution is derived based on the potential-flow theory for evaluating maximum groundwater pumping rates in a domain with a constant hydraulic head landward boundary. An empirical correction factor, which was introduced by Pool and Carrera (2011) to account for mixing in the case with a constant recharge rate boundary condition, is found also applicable for the case with a constant hydraulic head boundary condition, and therefore greatly improves the usefulness of the sharp-interface analytical solution. Comparing with the solution for a constant recharge rate boundary, we find that a constant hydraulic head boundary often yields larger estimations of the maximum pumping rate and when the domain size is five times greater than the distance between the well and the coastline, the effect of setting different landward boundary conditions becomes insignificant with a relative difference between two solutions less than 2.5%. These findings can serve as a preliminary guidance for conducting numerical simulations and designing tank-scale laboratory experiments for studying groundwater withdrawal problems in coastal aquifers with minimized boundary condition effects.

  11. Water security and services in the ocean-aquifer system

    Science.gov (United States)

    Taniguchi, M.

    2011-12-01

    Coastal vulnerability and water security are both important research subjects on global environmental problems under the pressures of changing climate and societies. A six years research project by RIHN on the coastal subsurface environments in seven Asia cities revealed that subsurface environmental problems including saltwater intrusion, groundwater contamination and subsurface thermal anomalies occurred one after another depending on the development stage of the cities during the last 100 years. Exchanges of water between ocean and aquifer in the coastal cities depend on driving force from land of natural resources capacities such as groundwater recharge rate, and social changes such as excessive groundwater pumping due to industrialization. Risk assessments and managements for aquifers which are parts of water security have been made for seven Asian coastal cities. On the other hand, submarine groundwater discharge (SGD) into the ocean provides water services directly to the coastal ecosystem through nutrient transports from land to the ocean. Constant geophysical and geochemical conditions served by SGD provide sustainable services to the coastal environment. Flora and fauna which prefer brackish water in the coastal zone depend on not only river water discharge but also SGD. Ocean -aquifer interaction can be found in the coastal ecosystem including sea shell, sea grass and fishes in the coastal zone though SGD. In order to evaluate a coastal security and sustainable environment, not only risk assessments due to disasters but also water services are important, and the both are evaluated in Asian coastal zones.

  12. Transient heterogeneity in an aquifer undergoing bioremediation of hydrocarbons.

    Science.gov (United States)

    Schillig, P C; Devlin, J F; Roberts, J A; Tsoflias, G P; McGlashan, M A

    2011-01-01

    Localized, transient heterogeneity was studied in a sand aquifer undergoing benzene, toluene, ethylbenzene, and xylene bioremediation using a novel array of multilevel, in situ point velocity probes (PVPs). The experiment was conducted within a sheet-pile alleyway to maintain a constant average flow direction through time. The PVPs measured changes in groundwater velocity direction and magnitude at the centimeter scale, making them ideal to monitor small-scale changes in hydraulic conductivity (K). Velocities were shown to vary nonuniformly by up to a factor of 3 when a source of oxygen was established down-gradient of the petroleum spill. In spite of these local variations, the average groundwater velocity within the 7 m × 20 m sheet-piled test area only varied within ± 25%. The nonuniform nature of the velocity variations across the gate indicated that the changes were not due solely to seasonal hydraulic gradient fluctuations. At the conclusion of the experiment, microbial biomass levels in the aquifer sediments was approximately 1 order of magnitude higher in the oxygen-amended portion of the aquifer than at the edge of the plume or in locations up-gradient of the source. These data suggest that the transient velocities resulted, at least in part, from enhanced biological activity that caused transient heterogeneities in the porous medium.

  13. Seawater intrusion and pumping wells in coastal aquifers

    Science.gov (United States)

    Nadjafzadeh Anvar, Amir; Riva, Monica

    2017-04-01

    Coastal aquifers are affected by seawater intrusion (SWI), this problem is exacerbated by groundwater extractions. In this work, we analyze key parameters affecting pumping wells contamination in costal aquifers. The USGS SUTRA code is employed to solve numerically flow and transport and to characterize SWI under diverse groundwater withdrawal scenarios. We developed two- and three-dimensional variable-density flow and solute transport models, respectively representing the existence of a pumping well barrier and of a single pumping well. The impact of the joint extraction of fresh- and salt- water has also been considered. We then analyzed the effect of (i) the location and pumping rate of fresh- and salt- water pumping wells (ii) the permeability of the aquifer as well as (iii) the transverse and longitudinal dispersivity on the maximum pumping time, tmax. The latter is defined as the maximum freshwater pumping time preventing the well to be contaminated by salt water. Finally we derived empirical equations to be used in practical applications to evaluate tmax as a function of key parameters highlighted.

  14. Injection and trapping of carbon dioxide in deep saline aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Saylor, B.Z.; Zerai, B. [Case Western Reserve University, Cleveland, OH (United States). Dept. of Geological Sciences

    2004-10-22

    Carbon dioxide collected from the waste streams of point sources can be injected into deep geologic formations in order to limit the emission of greenhouse gases to the atmosphere. Deep saline aquifers provide the largest potential subsurface storage capacity for injected CO{sub 2}. Once injected, free CO{sub 2} can be retained in deep aquifers for long time periods by slow-moving, downward-directed formation waters. Over time, the injected CO{sub 2} will dissolve in the formation waters and through reactions with formation minerals, may be converted to carbonate minerals, resulting in permanent sequestration. Factors that influence the mass of CO{sub 2} that can be injected and stored in free or aqueous form, and as mineral phases, are reviewed and applied to estimate storage capacity of the Rose Run Sandstone, a saline aquifer beneath eastern Ohio, USA. It is estimated that 30 years of CO{sub 2} emissions from five of Ohio's largest coal-fired power plants can be injected into the Rose Run Sandstone and, over time, converted to aqueous and ultimately, mineral phases. 48 refs., 7 figs., 2 tabs.

  15. Modeling impact of small Kansas landfills on underlying aquifers

    Science.gov (United States)

    Sophocleous, M.; Stadnyk, N.G.; Stotts, M.

    1996-01-01

    Small landfills are exempt from compliance with Resource Conservation and Recovery Act Subtitle D standards for liner and leachate collection. We investigate the ramifications of this exemption under western Kansas semiarid environments and explore the conditions under which naturally occurring geologic settings provide sufficient protection against ground-water contamination. The methodology we employed was to run water budget simulations using the Hydrologic Evaluation of Landfill Performance (HELP) model, and fate and transport simulations using the Multimedia Exposure Assessment Model (MULTIMED) for several western Kansas small landfill scenarios in combination with extensive sensitivity analyses. We demonstrate that requiring landfill cover, leachate collection system (LCS), and compacted soil liner will reduce leachate production by 56%, whereas requiring only a cover without LCS and liner will reduce leachate by half as much. The most vulnerable small landfills are shown to be the ones with no vegetative cover underlain by both a relatively thin vadose zone and aquifer and which overlie an aquifer characterized by cool temperatures and low hydraulic gradients. The aquifer-related physical and chemical parameters proved to be more important than vadose zone and biodegradation parameters in controlling leachate concentrations at the point of compliance. ??ASCE.

  16. Potential Aquifer Vulnerability in Regions Down-Gradient from ...

    Science.gov (United States)

    Sandstone-hosted roll-front uranium ore deposits originate when U(VI) dissolved in groundwater is reduced and precipitated as insoluble U(IV) minerals. Groundwater redox geochemistry, aqueous complexation, and solute migration are instrumental in leaching uranium from source rocks and transporting it in low concentrations to a chemical redox interface where it is deposited in an ore zone typically containing the uranium minerals uraninite, pitchblende, and/or coffinite; various iron sulfides; native selenium; clays; and calcite. In situ recovery (ISR) of these uranium ores is a process of contacting the uranium mineral deposit with leaching (lixiviant) fluids via injection of the lixiviant into wells drilled into the subsurface aquifer that hosts uranium ore, while other extraction wells pump the dissolved uranium after dissolution of the uranium minerals. Environmental concerns during and after ISR include water quality impacts from: 1) potential excursions of leaching solutions away from the injection zone into down-dip, underlying, or overlying aquifers; 2) potential migration of uranium and its decay products (e.g., Ra, Rn, Pb); and, 3) potential migration of redox-sensitive trace metals (e.g., Fe, Mn, Mo, Se, V), metalloids (e.g., As), and anions (e.g., sulfate). This review describes the geochemical processes that control roll-front uranium transport and fate in groundwater systems, identifies potential aquifer vulnerabilities to ISR operations, identifies

  17. Assessing the risk of saltwater intrusion in coastal aquifers

    Science.gov (United States)

    Klassen, J.; Allen, D. M.

    2017-08-01

    In coastal regions, the quality of groundwater can be compromised due to saltwater intrusion (SWI) caused by natural (sea level rise (SLR) and storm surge) and anthropogenic (pumping) hazards. The goal of this research was to develop and test an approach for assessing the risk of SWI in coastal aquifers. The Gulf Islands in British Columbia (BC) was the case study area. The vulnerability of the bedrock aquifers to SWI was assessed spatially by mapping hazards in combination with the aquifer susceptibility. Climate change related hazards, including SLR and storm surge overwash, were integrated into floodplain maps for each island using projected SLR data for 2100 in combination with estimated storm surge levels based on data collected over a forty year period. When combined with maps showing the density of pumping wells, coastal zones that may be at higher risk of SWI were identified for this particular coastal area of BC. Hazards due to pumping have the greatest influence on the vulnerability. Risk was evaluated spatially using an economic valuation of loss - here replacement of a water supply. The combination of chemical indicators of SWI and risk assessment maps are potentially useful tools for identifying areas vulnerable to SWI, and these tools can be used to improve decision-making related to monitoring and community development for coastal areas, thereby increasing resilience.

  18. Sequestration of carbon in saline aquifers - mathematical and numerical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nordbotten, Jan Martin

    2004-01-01

    The work in this thesis focuses equally on two main topics. The set of these subjects deals with development of criteria for monotonicity of control volume methods. These methods are important and frequently used for solving the pressure equation arising in porous media flow. First we consider homogeneous parallelogram grids, and subsequently general logical Cartesian grids in heterogeneous media. This subject is concluded by the development of a new class of Multi Point Flux Approximation methods, motivated by the monotonicity results obtained. The second topic of this thesis is the development of analytical and semi- analytical solutions to the problem of leakage through abandoned wells. More specially, we look at a set of aquifers, separated by impermeable layers (aquicludes), where injection of water or CO{sub 2} takes place in some or all the aquifers. The aquifers and aquicludes are frequently penetrated by abandoned wells from oil exploration, and our problem consists of finding solutions to flow and leakage through these wells. The goal is to obtain expressions for leakage rates that may be evaluated quickly enough such that Monte Carlo realizations over statistical distributions of properties for abandoned wells can be performed. (author)

  19. Can arsenic occurrence rates in bedrock aquifers be predicted?

    Science.gov (United States)

    Yang, Qiang; Jung, Hun Bok; Marvinney, Robert G.; Culbertson, Charles W.; Zheng, Yan

    2012-01-01

    A high percentage (31%) of groundwater samples from bedrock aquifers in the greater Augusta area, Maine was found to contain greater than 10 µg L−1 of arsenic. Elevated arsenic concentrations are associated with bedrock geology, and more frequently observed in samples with high pH, low dissolved oxygen, and low nitrate. These associations were quantitatively compared by statistical analysis. Stepwise logistic regression models using bedrock geology and/or water chemistry parameters are developed and tested with external data sets to explore the feasibility of predicting groundwater arsenic occurrence rates (the percentages of arsenic concentrations higher than 10 µg L−1) in bedrock aquifers. Despite the under-prediction of high arsenic occurrence rates, models including groundwater geochemistry parameters predict arsenic occurrence rates better than those with bedrock geology only. Such simple models with very few parameters can be applied to obtain a preliminary arsenic risk assessment in bedrock aquifers at local to intermediate scales at other localities with similar geology. PMID:22260208

  20. Review: Thermal water resources in carbonate rock aquifers

    Science.gov (United States)

    Goldscheider, Nico; Mádl-Szőnyi, Judit; Erőss, Anita; Schill, Eva

    2010-09-01

    The current knowledge on thermal water resources in carbonate rock aquifers is presented in this review, which also discusses geochemical processes that create reservoir porosity and different types of utilisations of these resources such as thermal baths, geothermal energy and carbon dioxide (CO2) sequestration. Carbonate aquifers probably constitute the most important thermal water resources outside of volcanic areas. Several processes contribute to the creation of porosity, summarised under the term hypogenic (or hypogene) speleogenesis, including retrograde calcite solubility, mixing corrosion induced by cross-formational flow, and dissolution by geogenic acids from deep sources. Thermal and mineral waters from karst aquifers supply spas all over the world such as the famous bath in Budapest, Hungary. Geothermal installations use these resources for electricity production, district heating or other purposes, with low CO2 emissions and land consumption, e.g. Germany’s largest geothermal power plant at Unterhaching near Munich. Regional fault and fracture zones are often the most productive zones, but are sometimes difficult to locate, resulting in a relatively high exploration uncertainty. Geothermal installations in deep carbonate rocks could also be used for CO2 sequestration (carbonate dissolution would partly neutralise this gas and increase reservoir porosity). The use of geothermal installations to this end should be further investigated.

  1. Microbial monitoring during CO2 storage in deep subsurface saline aquifers in Ketzin, Germany

    Science.gov (United States)

    Wuerdemann, H.; Wandrey, M.; Fischer, S.; Zemke, K.; Let, D.; Zettlitzer, M.; Morozova, D.

    2010-12-01

    Investigations on subsurface saline aquifers have shown an active biosphere composed of diverse groups of microorganisms in the subsurface. Since microorganisms represent very effective geochemical catalysts, they may influence the process of CO2 storage significantly. In the frames of the EU Project CO2SINK a field laboratory to study CO2 storage into saline aquifer was operated. Our studies aim at monitoring of biological and biogeochemical processes and their impact on the technical effectiveness of CO2 storage technique. The interactions between microorganisms and the minerals of both the reservoir and the cap rock may cause changes to the structure and chemical composition of the rock formations, which may influence the reservoir permeability locally. In addition, precipitation and corrosion may be induced around the well affecting the casing and the casing cement. Therefore, analyses of the composition of microbial communities and its changes should contribute to an evaluation of the effectiveness and reliability of the long-term CO2 storage technique. In order to investigate processes in the deep biosphere caused by the injection of supercritical CO2, genetic fingerprinting (PCR SSCP Single-Strand-Conformation Polymorphism) and FISH (Fluorescence in situ Hybridisation) were used for identification and quantification of microorganisms. Although saline aquifers could be characterised as an extreme habitat for microorganisms due to reduced conditions, high pressure and salinity, a high number of diverse groups of microorganisms were detected with downhole sampling in the injection and observation wells at a depth of about 650m depth. Of great importance was the identification of the sulphate reducing bacteria, which are known to be involved in corrosion processes. Microbial monitoring during CO2 injection has shown that both quantity and diversity of microbial communities were strongly influenced by the CO2 injection. In addition, the indigenous microbial

  2. Spatial variability of hydraulic conductivity of an unconfined sandy aquifer determined by a mini slug test

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Hinsby, Klaus; Christensen, Thomas Højlund;

    1992-01-01

    The spatial variability of the hydraulic conductivity in a sandy aquifer has been determined by a mini slug test method. The hydraulic conductivity (K) of the aquifer has a geometric mean of 5.05 × 10−4 m s−1, and an overall variance of 1n K equal to 0.37 which corresponds quite well to the results...... obtained by two large scale tracer experiments performed in the aquifer. A geological model of the aquifer based on 31 sediment cores, proposed three hydrogeological layers in the aquifer concurrent with the vertical variations observed with respect to hydraulic conductivity. The horizontal correlation...... length of the hydraulic conductivity has been determined for each of the three hydrogeological layers and is found to be small (1–2.5 m). The asymptotic longitudinal dispersivity of the aquifer has been estimated from the variance in hydraulic conductivity and the horizontal correlation length...

  3. Annual INTEC Groundwater Monitoring Report for Group 5 - Snake River Plain Aquifer (2001)

    Energy Technology Data Exchange (ETDEWEB)

    Roddy, M.S.

    2002-02-28

    This report describes the monitoring activities conducted and presents the results of groundwater sampling and water-level measurements from October 2000 to September 2001. Groundwater samples were initially collected from 41 wells from the Idaho Nuclear Technology and Engineering Center and the Central Facilities Area and analyzed for iodine- 129, strontium-90, tritium, gross alpha, gross beta, technetium-99, uranium isotopes, plutonium isotopes, neptunium-237, gamma spectrometry, and mercury. Samples from 41 wells were collected in April and May 2001. Additional sampling was conducted in August 2001 and included in two CFA production wells, the CFA point of compliance for the production wells, one well was previously sampled and five additional monitoring wells. Water-level measurements were taken from in the Idaho Nuclear Technology and Engineering Center, Central Facilities Area, and the area south of Central Facilities Area to evaluate groundwater flow directions. Water-level measurements indicated groundwater flow to the south-southwest from the Idaho Nuclear Technology and Engineering Center.

  4. Origin of brackish groundwater in a sandstone aquifer on Bornholm, Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Niels Oluf; Heinemeier, Jan

    2008-01-01

    ). The occurrence of brackish groundwater is remarkable for this aquifer, which otherwise yields potable groundwater of good quality. The stable isotope (18O and 2H) compositions indicate a meteoric origin of the brackish groundwater, which rules out seawater intrusion into the aquifer. 14C activities show apparent...... reflecting long water-rock interaction and suggest a contribution of palaeowater from the fractured crystalline basement which has intruded into the Lower Cambrian sandstone aquifer....

  5. Group morphology

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2000-01-01

    In its original form, mathematical morphology is a theory of binary image transformations which are invariant under the group of Euclidean translations. This paper surveys and extends constructions of morphological operators which are invariant under a more general group TT, such as the motion group

  6. Hydrogeology and water quality of the Floridan aquifer system and effects of Lower Floridan aquifer pumping on the Upper Floridan aquifer at Fort Stewart, Georgia

    Science.gov (United States)

    Clarke, John S.; Cherry, Gregory C.; Gonthier, Gerard J.

    2011-01-01

    Test drilling, field investigations, and digital modeling were completed at Fort Stewart, GA, during 2009?2010, to assess the geologic, hydraulic, and water-quality characteristics of the Floridan aquifer system and evaluate the effect of Lower Floridan aquifer (LFA) pumping on the Upper Floridan aquifer (UFA). This work was performed pursuant to the Georgia Environmental Protection Division interim permitting strategy for new wells completed in the LFA that requires simulation to (1) quantify pumping-induced aquifer leakage from the UFA to LFA, and (2) identify the equivalent rate of UFA pumping that would produce the same maximum drawdown in the UFA that anticipated pumping from LFA well would induce. Field investigation activities included (1) constructing a 1,300-foot (ft) test boring and well completed in the LFA (well 33P028), (2) constructing an observation well in the UFA (well 33P029), (3) collecting drill cuttings and borehole geophysical logs, (4) collecting core samples for analysis of vertical hydraulic conductivity and porosity, (5) conducting flowmeter and packer tests in the open borehole within the UFA and LFA, (6) collecting depth-integrated water samples to assess basic ionic chemistry of various water-bearing zones, and (7) conducting aquifer tests in new LFA and UFA wells to determine hydraulic properties and assess interaquifer leakage. Using data collected at the site and in nearby areas, model simulation was used to assess the effects of LFA pumping on the UFA. Borehole-geophysical and flowmeter data indicate the LFA at Fort Stewart consists of limestone and dolomitic limestone between depths of 912 and 1,250 ft. Flowmeter data indicate the presence of three permeable zones at depth intervals of 912-947, 1,090-1,139, and 1,211?1,250 ft. LFA well 33P028 received 50 percent of the pumped volume from the uppermost permeable zone, and about 18 and 32 percent of the pumped volume from the middle and lowest permeable zones, respectively. Chemical

  7. Assessment of chemical quality of groundwater in coastal volcano-sedimentary aquifer of Djibouti, Horn of Africa

    Science.gov (United States)

    Ahmed, Abdoulkader Houssein; Rayaleh, Waiss Elmi; Zghibi, Adel; Ouddane, Baghdad

    2017-07-01

    This research is conducted to evaluate the current status of hydrogeochemical contaminants and their sources in groundwater in the volcano-sedimentary aquifer of Djibouti. Groundwater samples were mostly collected from the volcanic and inferoflux aquifers and then were analyzed for quality on physicochemical parameters (EC, pH, Temperature, Cl-, SO42-, HCO3-, NO3-, Na+, Ca2+, Mg2+, K+, Br-, F-), minor and trace elements (Li, Ba, B, Sr, Si, Al, Cr, Fe, Mn, Mo, Pb, Co, Cu, Ni, Zn, Ti, V, As, Se). The interpretations of hydrochemical data are shown numerically and graphically through the Piper diagram such as the multivariate statistical analysis, binary diagram, the calculation of the saturation indexes, the index of base exchanges and ratio of Na+/Cl-, SO42-/Cl-, HCO3-/Cl-. The seawater ratio and ionic deviation in the groundwater were calculated using the chloride concentration. These processes can be used as indicators of seawater intrusion progress. This study reveals three groundwater quality groups and how the quality of water supply has been deteriorated through the process of seawater intrusion. The seawater intrusion extends into the Gulf basalts aquifer that covers nearly 12% of the whole area according to some observations. Some toxic elements present in drinking water (As and Se) have already exceeded the maximum permissible in almost the entire of the Gulf basalts aquifer affected by seawater intrusion. Indeed, some correlations were found between As, Se, with electrical conductivity and among other minor and trace elements such as Br, B, Sr, Co and Cr. It indicates that all these elements are mainly controlled by naturel/geogenic processes. The Principal component Analysis and the Hierarchical Cluster Analysis have led to the confirmation of the hypotheses developed in the previous hydrochemical study in which two factors explain the major hydrochemical processes in the aquifer. These factors reveal first the existence of an intensive intrusion of

  8. Options of sustainable groundwater supply from safe aquifers in areas with elevated arsenic - a case study from Bangladesh

    Science.gov (United States)

    Jakariya, M.; Bhattacharya, P.; Bromssen, M. V.

    2008-05-01

    Access to safe drinking water is a basic human right. Several millions of people, mainly in developing countries are affected by arsenic in drinking water and the global impact now makes it a top priority water quality issue. A wide gap between the number of exposed people and the pace of mitigation programmes in rural areas of developing countries is the main problem in providing safe drinking water. The main challenge is to develop a sustainable mitigation option that rural and disadvantaged people can adopt and implement themselves to overcome possible public heath hazards. During the recent years, new approaches have emerged in Bangladesh, primarily emerging out of people's own initiative. The local drillers target presumed safe aquifers on the basis of colour and texture of the sediments. A recent study by our research group revealed a distinct correlation between the colour characteristics of the sediments and the groundwater redox conditions. The coupling between the colour of sediments and the redox characteristics of groundwater may thus be used as a tool to assess the risk for As mobilization from the aquifers. The study showed that it is possible to assess the relative risk of high concentrations of As in aquifers if the colour characteristics of the sediments are known and thus, local drillers may target safe aquifers. For validating the sustainability of this mitigation option geological, hydrogeological and microbiological investigations are needed. The sustainability of the aquifers needs to be assessed by combining results from various field and laboratory investigations and by running predictive models. There is also a need to raise the awareness and thereby create a platform for motivating the local drillers to be educated in installing safe tubewells. Awareness raising and community mobilisation are two top priorities for implementing a sustainable safe water project in rural village areas. Significant preparation, attention, and focus must be

  9. Monitoring of emerging contaminants (pharmaceuticals, Personal Care Products, surfactants and heavy metals) in a quaternary detritic aquifer

    Science.gov (United States)

    Candela, L.; Valdes-Abellan, J.; Jiménez-Martínez, J.

    2012-04-01

    The presence of 209 emerging compounds, surfactants, priority substances according to the 2008/105/EC Directive, 10 heavy metals and microbiological organisms in blended water and aquifer samples was investigated in a quaternary aquifer. The effects of these compounds over the environment are not clear in many cases, but many of them have been classified as endocrine disruptor compounds, EDC. Their presence in the media is controlled in one hand by their transformation and/or removal rates and, on the other hand, by their continuous release into the media, due to the broad use of these in many human activities (pharmaceuticals, personal care products, pesticides, heavy metals, LAS and others). The attention of this work focusses on the presence and fate of these substances in the vadose zone and the aquifer. The aquifer catchment (81km2) located in SE Spain presents a high natural salinity (with EC values of ~7,500 μS cm-1, and high concentrations of chloride, sulphate and sodium), making it unsuitable to be used as drinking water or irrigation. Two sampling campaigns (February and June 2011) in wells and springs have been carried out top characterize physic-chemical, microbiological and emerging contaminants presence in the aquifer. A total of 209 emerging pollutants grouped into the following classes were analysed: 125 pharmaceutical compounds (Phs), 20 polyaromatic hydrocarbons (PAHs) and Dioxins, 46 pesticides, 3 volatile priority pollutants as well as the most commonly used anionic surfactants were identified for further analysis. Heavy metals included: Cu, Cd, Pb, Hg, Ni, Zn, Sn, Pt, Pd and Tl. Results showed that 39 out of all compounds were detected: 11 pharmaceuticals, 9 PAHs, 19 pesticides, 4 surfactants and 4 heavy metals. Two of the compounds, endosulfan-α and Ni, were detected in concentrations above the allowed regulation. Although results are limited to 2 sampling campaigns, it is important to note that surfactants (LAS), pesticides PAHs and

  10. Numerical long-term assessment of managed aquifer recharge from a reservoir into a karst aquifer in Jordan

    Science.gov (United States)

    Xanke, Julian; Jourde, Hervé; Liesch, Tanja; Goldscheider, Nico

    2016-09-01

    In semi-arid regions with high seasonal variability of water availability, adaptive management strategies and technical measures are required to ensure the sustainable use of water resources. In this study, managed recharge of storm water into a karst aquifer and the water level fluctuations related to pumping in a nearby wellfield were simulated at Wadi Wala, Jordan. We used a numerical equivalent porous medium (EPM) approach with specific adaptations to account for the heterogeneity and anisotropy of the karst aquifer. The model domain was vertically projected along the wadi course, resulting in a 2-dimensional model, and subdivided into hydraulic zones representing the karst-specific flow pattern of fast flow and slow depletion. Results show satisfying agreement of measured and simulated groundwater tables from 2002 to 2012 and predict a lowering of the average groundwater table until 2022 of around 2.7 m in the immediate surroundings of the reservoir and an increased depletion towards the wellfield, mainly caused by sedimentation in the reservoir and an associated decrease in infiltration. Abstraction at the wellfield changed considerably over the regarded time period and strongly influences the groundwater fluctuations, which shows the need of improved pumping management and monitoring. The results can serve as a basis for decision makers regarding an optimization of water management at the reservoir and wellfield. Furthermore, the presented numerical approach can be transferred to karst regions with similar physio-geographical conditions to assess managed aquifer recharge.

  11. 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

  12. Middle Claiborne Aquifer: Alabama, Arkansas, Illinois, Kentucky, Louisiana, Missouri, Mississippi, Tennessee 2006-2008

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Outcrop and subcrop extent of the Middle Claiborne Aquifer in Alabama, Arkansas, Illinois, Kentucky, Louisiana, Missouri, Mississippi, Tennessee.

  13. Origin and structures of groundwater humic substances from three Danish aquifers

    DEFF Research Database (Denmark)

    Grøn, C.; Wassenaar, L.; Krog, M.

    1996-01-01

    Structural, chemical, and isotopic parameters were used to identify the origins of groundwater humic substances from three Danish aquifers. A variety of analytical techniques (visible light absorption, molecular weight distribution, C-13-NMR spectroscopy, elemental composition with major elements...... and halogens, hydrolyzable amino acids and carbohydrates, carbon isotopes) applied to aquatic humic and fulvic acids led to consistent structural interpretations for each of the three aquifers studied. For humic substances in two-aquifers, the analyses suggested source rocks in agreement with geological...... and hydrogeochemical information. In a third aquifer, source rock identification was inconclusive, and multiple fossil and recent organic carbon sources are suggested....

  14. Prediction of oil contamination distribution in aquifers using self similar solutions

    Science.gov (United States)

    Pistiner, Arieh

    2016-12-01

    Oil contaminant migration in an aquifer is analyzed by applying some power law relationships between the porous medium parameters and oil saturation. Such an application generates a self-similar model whose solutions are used to analyze the effect of the porous structure and the oil properties on the oil migration in the aquifer. By using hypothetical saturation data, the model was used to find the characteristic length and time scales of the aquifer, and then to predict the temporal saturation distribution of the oil contamination in the aquifer.

  15. Landfill leachate effects on sorption of organic micropollutants onto aquifer materials

    DEFF Research Database (Denmark)

    Larsen, Thomas; Christensen, Thomas Højlund; Pfeffer, Fred M.;

    1992-01-01

    content. The experiments showed that hydrophobic organic micropollutants do partition into dissolved organic carbon found in landfill leachate potentially increasing their mobility. However, landfill leachate interacted with aquifer materials apparently increases the sorbent affinity for the hydrophobic......The effect of dissolved organic carbon as present in landfill leachate, on the sorption of organic micropollutants in aquifer materials was studied by laboratory batch and column experiments involving 15 non-polar organic chemicals, 5 landfill leachates and 4 aquifer materials of low organic carbon......, the effect of landfill leachate on retardation of organic micropollutants in aquifer material seems limited....

  16. Characterising Bedrock Aquifer Systems in Korea Using Paired Water-Level Monitoring Data

    Directory of Open Access Journals (Sweden)

    Jae Min Lee

    2017-06-01

    Full Text Available This study focused on characterising aquifer systems based on water-level changes observed systematically at 159 paired groundwater monitoring wells throughout Korea. Using spectral analysis, principal component analysis (PCA, and cross-correlation analysis with linear regression, aquifer conditions were identified from the comparison of water-level changes in shallow alluvial and deep bedrock monitoring wells. The spectral analysis could identify the aquifer conditions (i.e., unconfined, semi-confined and confined of 58.5% of bedrock wells and 42.8% of alluvial wells: 93 and 68 wells out of 159 wells, respectively. Even among the bedrock wells, 50 wells (53.7% exhibited characteristics of the unconfined condition, implying significant vulnerability of the aquifer to contaminants from the land surface and shallow depths. It appears to be better approach for deep bedrock aquifers than shallow alluvial aquifers. However, significant portions of the water-level changes remained unclear for categorising aquifer conditions due to disturbances in data continuity. For different aquifer conditions, PCA could show typical pattern and factor scores of principal components. Principal component 1 due to wet-and-dry seasonal changes and water-level response time was dominant covering about 55% of total variances of each aquifer conditions, implying the usefulness of supplementary method of aquifer characterisation. Cross-correlation and time-lag analysis in the water-level responses to precipitations clearly show how the water levels in shallow and deep wells correspond in time scale. No significant differences in time-lags was found between shallow and deep wells. However, clear time-lags were found to be increasing from unconfined to confined conditions: from 1.47 to 2.75 days and from 1.78 to 2.75 days for both shallow alluvial and deep bedrock wells, respectively. In combination of various statistical methods, three types of water-level fluctuation

  17. Disposal of carbon dioxide in aquifers in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Winter, E.M.; Bergman, P.D.

    1995-11-01

    Deep saline aquifers were investigated as potential disposal sites for CO{sub 2}. The capacity of deep aquifers for CO{sub 2} disposal in the U.S. is highly uncertain. A rough estimate, derived from global estimates, is 5,500 Gt of CO{sub 2}. Saline aquifers underlie the regions in the U.S. where most utility power plants are situated. Therefore, approximately 65 percent of CO{sub 2} from power plants could possibly be injected directly into deep saline aquifers below these plants, without the need for long pipelines.

  18. Middle Claiborne Aquifer: Alabama, Arkansas, Illinois, Kentucky, Louisiana, Missouri, Mississippi, Tennessee 2006-2008

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital hydrogeologic surface of the Middle Claiborne Aquifer in Alabama, Arkansas, Illinois, Kentucky, Louisiana, Missouri, Mississippi, Tennessee. The...

  19. Managed Aquifer Recharge in Italy: present and prospects.

    Science.gov (United States)

    Rossetto, Rudy

    2015-04-01

    On October the 3rd 2014, a one-day Workshop on Managed Aquifer Recharge (MAR) experiences in Italy took place at the GEOFLUID fair in Piacenza. It was organized within the framework of the EIP AG 128 - MAR Solutions - Managed Aquifer Recharge Strategies and Actions and the EU FPVII MARSOL. The event aimed at showcasing present experiences on MAR in Italy while at the same time starting a network among all the Institutions involved. In this contribution, we discuss the state of MAR application in Italy and summarize the outcomes of that event. In Italy aquifer recharge is traditionally applied unintentionally, by increasing riverbank filtration or because of excess irrigation. A certain interest for artificial recharge of aquifers arose at the end of the '70s and the beginning of the '80s and tests have been carried out in Tuscany, Veneto and Friuli Venezia Giulia. During the last years some projects on aquifer recharge were co-financed by the European Commission mainly through the LIFE program. Nearly all of them use the terminology of artificial recharge instead of MAR. They are: - TRUST (Tool for regional - scale assessment of groundwater storage improvement in adaptation to climate change, LIFE07 ENV/IT/000475; Marsala 2014); - AQUOR (Implementation of a water saving and artificial recharging participated strategy for the quantitative groundwater layer rebalance of the upper Vicenza's plain - LIFE 2010 ENV/IT/380; Mezzalira et al. 2014); - WARBO (Water re-born - artificial recharge: innovative technologies for the sustainable management of water resources, LIFE10 ENV/IT/000394; 2014). While the TRUST project dealt in general with aquifer recharge, AQUOR and WARBO focused essentially on small scale demonstration plants. Within the EU FPVII-ENV-2013 MARSOL project (Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought; 2014), a dedicated monitoring and decision support system is under development to manage recharge at a large scale

  20. Ground Surface Deformations Near a Fault-Bounded Groundwater Aquifer

    Science.gov (United States)

    Lipovsky, B.; Funning, G. J.; Ferretti, A.

    2011-12-01

    Geodetic data often reveal the presence of groundwater aquifers that are bounded by faults (Schmidt and Bürgmann, 2003; Galloway and Hoffmann, 2007; Bell et al., 2008). Whereas unrestricted groundwater aquifers exhibit a radially symmetric pattern of uplift with diffuse boundaries, aquifers that are bounded by faults have one or more sharp, linear boundaries. Interferometric synthetic aperture (InSAR) data, due to their high spatial density, are particularly well suited to observe fault bounded aquifers, and the Santa Clara Aquifer in the San Francisco Bay Area, California, constitutes an excellent example. The largest ground surface displacements in the Bay Area are due to the inflation of the Santa Clara aquifer, and InSAR data plainly show that the Santa Clara aquifer is partitioned by the Silver Creek fault. This study first develops a general model of the displacements at the surface of the Earth due to fluid diffusion through a buried permeable boundary such as a fault zone. This model is compared to InSAR data from the Silver Creek fault and we find that we are able to infer fault zone poromechanical properties from InSAR data that are comparable to in situ measurements. Our theoretical model is constrained by several geological and hydrological observations concerning the structure of fault zones. Analytical solutions are presented for the ground surface displacements due to a perfectly impermeable fault zone. This end-member family of models, however, does not fit the available data. We therefore make allowance for an arbitrarily layered, variably permeable, one-dimensional fault zone. Time-dependent ground surface deformations are calculated in the Laplace domain using an efficient semi-analytic method. This general model is applicable to other poroelastic regimes including geothermal and hydrocarbon systems. We are able to estimate fault zone hydraulic conductivity by comparing theoretical ground surface displacements in a permeable fault zone to

  1. Monitoring induced denitrification in an artificial aquifer recharge system.

    Science.gov (United States)

    Grau-Martinez, Alba; Torrentó, Clara; Folch, Albert; Domènech, Cristina; Otero, Neus; Soler, Albert

    2014-05-01

    As demands on groundwater increase, artificial recharge is becoming a common method for enhancing groundwater supply. The Llobregat River is a strategic water supply resource to the Barcelona metropolitan area (Catalonia, NE Spain). Aquifer overexploitation has leaded to both a decrease of groundwater level and seawater intrusion, with the consequent deterioration of water quality. In the middle section of the aquifer, in Sant Vicenç del Horts, decantation and infiltration ponds recharged by water from the Llobregat River (highly affected from wastewater treatment plant effluents), were installed in 2007, in the framework of the ENSAT Life+ project. At the bottom of the infiltration pond, a vegetal compost layer was installed to promote the growth of bacteria, to induce denitrification and to create favourable conditions for contaminant biodegradation. This layer consists on a mixture of compost, aquifer material, clay and iron oxide. Understanding the fate of contaminants, such as nitrate, during artificial aquifer recharge is required to evaluate the impact of artificial recharge in groundwater quality. In order to distinguish the source of nitrate and to evaluate the capability of the organic reactive layer to induce denitrification, a multi-isotopic approach coupled with hydrogeochemical data was performed. Groundwater samples, as well as river samples, were sampled during artificial and natural recharge periods. The isotopic analysis included: δ15N and δ18O of dissolved nitrate, δ34S and δ18O of dissolved sulphate, δ13C of dissolved inorganic carbon, and δ2H and δ18O of water. Dissolved nitrate isotopic composition (δ15NNO3 from +9 to +21 o and δ18ONO3 from +3 to +16 ) demonstrated that heterotrophic denitrification induced by the reactive layer was taking place during the artificial recharge periods. An approximation to the extent of nitrate attenuation was calculated, showing a range between 95 and 99% or between 35 and 45%, by using the extreme

  2. Integrated hydrochemical method of water quality assessment for irrigation in arid areas: application to the Jilh aquifer, Saudi Arabia

    Science.gov (United States)

    Al-Bassam, Abdulaziz M.; Al-Rumikhani, Yousef A.

    2003-05-01

    Water samples from 72 wells tapping the Jilh aquifer were collected and analyzed for 10 different water quality parameters. Using these data, a regional irrigation water quality was assessed using three techniques: (i) United States Department of Agriculture method (USDA), (ii) Food and Agriculture Organization (FAO) guidelines for water quality assessment, and (iii) Water-Types approach. The USDA method revealed that the aquifer water salinity, as represented by electrical conductivity, ECw, ranges from high salinity (C3: ECw > 0.75-2.25 dS/m) to a very high salinity (C4: ECw > 2.25 dS/m). The sodium adsorption ratio (SAR) varied from low (S1) to very high (S4) sodicity. Therefore, the water of the Jilh aquifer is dominantly of the C4-S2 class representing 56% of the total wells followed by C4-S1, C4-S3, C3-S1 and C4-S4 classes at 19%, 14%, 8%, and 3% of the wells respectively. The FAO system indicated moderate to severe restriction on the use for irrigation and slight to moderate ion toxicities for Na+, Cl-, B+, NO3- and HCO3-. It is clear that, both USDA and FAO systems condemn the Jilh groundwater as hazardous for irrigation due to its high salt content, unless certain measures for salinity control are undertaken. The dominant salt constituents in the water are Mg-Cl2, Na-Cl and Ca-Cl2 as per the Water-Types method. However, due to the complexity in classifying the aquifer groundwater for irrigation, a simplified approach acknowledging three class groups (I-suitable water, II-conditionally suitable water and III-unsuitable water) adopted from the three methods, is suggested in this paper. The simplified approach combines C-S classes of the USDA method among these three groups according to the lowest ratings. The salinity of the FAO method has been split arbitrarily into slight and moderate subclasses with values of 0.7-2.25 and >2.25 dS/m, respectively; to match with the C3-class of the USDA system. The Water-Types were classified assuming that Ca-Cl2 is the

  3. Potentiometric Surfaces and Water-Level Trends in the Cockfield (Upper Claiborne) and Wilcox (Lower Wilcox) Aquifers of Southern and Northeastern Arkansas, 2009

    Science.gov (United States)

    Pugh, Aaron L.

    2010-01-01

    Eocene-age sand beds near the base of the Cockfield Formation of Claiborne Group constitute the aquifer known locally as the Cockfield aquifer. Upper-Paleocene age sand beds within the lower parts of the Wilcox Group constitute the aquifer known locally as the Wilcox aquifer. In 2005, reported water withdrawals from the Cockfield aquifer in Arkansas totaled 16.1 million gallons per day, while reported water withdrawals from the Wilcox aquifer in Arkansas totaled 27.0 million gallons per day. Major withdrawals from these units were for industrial and public water supplies with lesser but locally important withdrawals for commercial, domestic, and agricultural uses. During February 2009, 56 water-level measurements were made in wells completed in the Cockfield aquifer and 57 water-level measurements were made in wells completed in the Wilcox aquifer. The results from the 2009 water-level measurements are presented in potentiometric-surface maps and in combination with previous water-level measurements. Trends in water-level change over time within the two aquifers are investigated using water-level difference maps and well hydrographs. Water-level difference maps were constructed for each aquifer using the difference between depth to water measurements made in 2003 to 2009. Well hydrographs for each aquifer were constructed for wells with 20 or more years of historical water-level data. The hydrographs were evaluated individually using linear regression to calculate the annual rise or decline in water levels, and by aggregating the regression results by county and statistically summarizing for the range, mean, and median water-level change in each county. The 2009 potentiometric surface of the Cockfield aquifer map indicates the regional direction of groundwater flow generally towards the east and southeast, except in two areas of intense groundwater withdrawals that have developed into cones of depression. The lowest water-level altitude measured was 43 feet and the

  4. Integrating Spatial Multi Criteria Decision Making (SMCDM) with Geographic Information Systems (GIS) for delineation of the most suitable areas for aquifer storage and recovery (ASR)

    Science.gov (United States)

    Ahani Amineh, Zainab Banoo; Hashemian, Seyyed Jamal Al-Din; Magholi, Alireza

    2017-08-01

    Hamoon-Jazmoorian plain is located in southeast of Iran. Overexploitation of groundwater in this plain has led to water level decline and caused serious problems such as land subsidence, aquifer destruction and water quality degradation. The increasing population and agricultural development along with drought and climate change, have further increased the pressure on water resources in this region over the last years. In order to overcome such crisis, introduction of surface water into an aquifer at particular locations can be a suitable solution. A wide variety of methods have been developed to recharge groundwater, one of which is aquifer storage and recovery (ASR). One of the fundamental principles of making such systems is delineation of suitable areas based on scientific and natural facts in order to achieve relevant objectives. To that end, the Multi Criteria Decision Making (MCDM) in conjunction with the Geographic Information Systems (GIS) was applied in this study. More specifically, nine main parameters including depth of runoff as the considered source of water, morphology of the earth surface features such as geology, geomorphology, land use and land cover, drainage and aquifer characteristics along with quality of water in the aquifer were considered as the main layers in GIS. The runoff water available for artificial recharge in the basin was estimated through Soil Conservation Service (SCS) curve number method. The weighted curve number for each watershed was derived through spatial intersection of land use and hydrological soil group layers. Other thematic layers were extracted from satellite images, topographical map, and other collateral data sources, then weighed according to their influence in locating process. The Analytical Hierarchy Process (AHP) method was then used to calculate weights of individual parameters. The normalized weighted layers were then overlaid to build up the recharge potential map. The results revealed that 34% of the

  5. Potentiometric Surfaces and Water-Level Trends in the Cockfield and Wilcox Aquifers of Southern and Northeastern Arkansas, 2006

    Science.gov (United States)

    Schrader, T.P.

    2007-01-01

    The Cockfield Formation of Claiborne Group and the Wilcox Group contain aquifers that provide sources of ground water in southern and northeastern Arkansas. In 2000, about 9.9 million gallons per day was withdrawn from the Cockfield Formation of Claiborne Group and about 22.2 million gallons per day was withdrawn from the Wilcox Group. Major withdrawals from the aquifers were for industrial and public water supplies. A study was conducted by the U.S. Geological Survey in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey to determine the water level associated with the aquifers in the Cockfield Formation of Claiborne Group and the Wilcox Group in southern and northeastern Arkansas. During February and March 2006, 56 water-level measurements were made in wells completed in the Cockfield aquifer and 59 water-level measurements were made in wells completed in the Wilcox aquifer, 16 in southwestern and 43 in northeastern Arkansas. This report presents the results as potentiometric-surface maps and as long-term water-level hydrographs. The regional direction of ground-water flow in the Cockfield Formation of Claiborne Group generally is towards the east and southeast, away from the outcrop, except in areas of intense ground-water withdrawals, such as western Drew County, southeastern Lincoln County, southwestern Calhoun County, and near Crossett in Ashley County. There are three cones of depression indicated by relatively low water-level altitudes in southeastern Lincoln County, southwestern Calhoun County, and near Crossett in Ashley County. The lowest water-level altitude measured was 44 feet above the National Geodetic Vertical Datum of 1929 in Lincoln County; the highest water-level altitude measured was 346 feet above the National Geodetic Vertical Datum of 1929 in Columbia County at the outcrop area. Hydrographs from 40 wells with historical water levels from 1986 to 2006 were evaluated using linear regression to

  6. Group devaluation and group identification

    NARCIS (Netherlands)

    Leach, C.W.; Rodriguez Mosquera, P.M.; Vliek, M.L.W.; Hirt, E.

    2010-01-01

    In three studies, we showed that increased in-group identification after (perceived or actual) group devaluation is an assertion of a (preexisting) positive social identity that counters the negative social identity implied in societal devaluation. Two studies with real-world groups used order manip

  7. Hydrodynamic and salinity evolution of groundwaters during artificial recharge within semi-arid coastal aquifers: A case study of El Khairat aquifer system in Enfidha (Tunisian Sahel)

    Science.gov (United States)

    Ketata, Mouna; Gueddari, Moncef; Bouhlila, Rachida

    2014-09-01

    In common with most coastal aquifers, the El Khairat aquifer suffers the imbalance between recharge and intense exploitation and the extent of agricultural activity. As it is part of the Tunisian Sahel, the Enfidha region has a semiarid climate with very irregular rainfall which makes the groundwater resources quite fragile. This region has major difficulties in managing its water resources which are in decline, especially since, for the last decades, their renewal by rainwater has no longer been sufficient to re-establish the equilibrium. In such a case, the artificial recharge of aquifers by water from dams is a credible alternative to preserve the water resources against marine intrusion and pronounced fall in the piezometric level. The present investigation, based on available data, is aimed to monitoring the piezometry of the El Khairat aquifer during artificial recharge operations (2002-2005) by water from the dam and to identify the impact of the artificial recharge on groundwater quality. The results of this monitoring have shown that the artificial recharge realized between 2002 and 2005, had for effect an increase of the piezometric level of the phreatic aquifer of +0.4 to +2.63 m, especially in the “Ain Garci” zone. The piezometric level of the deep aquifer has also recorded an important increase reaching +3.82 m. After artificial recharge of the aquifer, the spatial distribution of the salinity shows quite low salinity values (lower than 2 g/l) in the western and north-eastern parts of the aquifer, the zone of artificial recharge, whereas the highest ones are found especially in the coastal zones and at the boundaries of the Sebkha where they exceeded 3 g/l. Moreover, we note a slight salinity reduction toward a central zone of the aquifer. Indeed, the zone characterized by salinity lower than 2 g/l and situated near the recharge site becomes more extensive.

  8. Consequences and mitigation of saltwater intrusion induced by short-circuiting during aquifer storage and recovery (ASR) in a coastal subsurface

    OpenAIRE

    Zuurbier, Koen Gerardus; Stuyfzand, Pieter Jan

    2016-01-01

    Coastal aquifers and the deeper subsurface are increasingly exploited. The accompanying perforation of the subsurface for those purposes has increased the risk of short-circuiting of originally separated aquifers. This study shows how this short-circuiting negatively impacts the freshwater recovery efficiency (RE) during aquifer storage and recovery (ASR) in coastal aquifers. ASR was applied in a shallow saltwater aquifer overlying a deeper saltwater aquifer, which was targeted for seasonal a...

  9. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent of the sand-and-gravel aquifer of the surficial aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  10. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent lines for permeable zones of the intermediate aquifer system and Brunswick aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  11. Reef and nonreef aquifers - A comparison of hydrogeology and geochemistry, northwestern Indiana

    Science.gov (United States)

    Schnoebelen, D.J.; Krothe, N.C.

    1999-01-01

    The principal bedrock aquifer system across much of Indiana consists of carbonate rocks of Silurian and Devonian age. The Silurian-Devonian aquifer system is used extensively for irrigation in northwestern Indiana and is approximately 170 m thick. Reef and nonreef carbonate aquifers in northwestern Indiana were assessed using hydrogeology (lithology, geophysical logs, aquifer tests) and geochemistry (major ions and stable isotopes). The study showed differences in water quantity and quality between the reef and nonreef aquifers. The reef aquifer had few shales, abundant fossiliferous material (up to 100 m thick), and high porosities (10 to 15%). The nonreef aquifer had abundant shales, less fossiliferous material (a few meters thick), and low porosities. Total transmissivities at the reef sites were 697 m2/d, (meters squared per day) and 4831 m2/d, compared to 46 m2/d at the nonreef site. Flowpaths in the nonreef aquifer were associated with fractures and poorly connected moldic porosity with larger fractures and better connected vuggy porosity in the reef aquifer. Water chemistry data for the nonreef aquifer showed mean concentrations of sodium (235 mg/L [milligrams per liter]), sulfate (160 mg/L), sulfide (13 mg/L), fluoride (2.7 mg/L), and dissolved solids (635 mg/L) approximately two to five times larger when compared to mean concentrations in the reef aquifer. Ground water at the nonreef site was classified as a sodium-bicarbonate type while that at the reef sites was calcium-magnesium bicarbonate. The oxygen/deuterium isotope data indicates recharge from modern precipitation and not Pleistocene-age recharge.The principal bedrock aquifer system across much of Indiana consists of carbonate rocks of Silurian and Devonian age. The Silurian-Devonian aquifer system is used extensively for irrigation in northwestern Indiana and is approximately 170 m thick. Reef and nonreef carbonate aquifers in northwestern Indiana were assessed using hydrogeology (lithology

  12. Fingerprinting TCE in a bedrock aquifer using compound-specific isotope analysis.

    Science.gov (United States)

    Lojkasek-Lima, Paulo; Aravena, Ramon; Parker, Beth L; Cherry, John A

    2012-01-01

    A dual isotope approach based on compound-specific isotope analysis (CSIA) of carbon (C) and chlorine (Cl) was used to identify sources of persistent trichloroethylene (TCE) that caused the shut-down in 1994 of a municipal well in an extensive fractured dolostone aquifer beneath Guelph, Ontario. Several nearby industrial properties have known subsurface TCE contamination; however, only one has created a comprehensive monitoring network in the bedrock. The impacted municipal well and many monitoring wells were sampled for volatile organic compounds (VOCs), inorganic parameters, and CSIA. A wide range in isotope values was observed at the study site. The TCE varies between -35.6‰ and -21.8‰ and from 1.6‰ to 3.2‰ for δ(13) C and δ(37) Cl, respectively. In case of cis-1,2-dichloroethene, the isotope values range between -36.3‰ and -18.9‰ and from 2.4‰ to 4.7‰ for δ(13) C and δ(37) Cl, respectively. The dual isotope approach represented by a plot of δ(13) C vs. δ(37) Cl shows the municipal well samples grouped in a domain clearly separate from all other samples from the property with the comprehensive well network. The CSIA results collected under non-pumping and short-term pumping conditions thus indicate that this particular property, which has been studied intensively for several years, is not a substantial contributor of the TCE presently in the municipal well under non-pumping conditions. This case study demonstrates that CSIA signatures would have been useful much earlier in the quest to examine sources of the TCE in the municipal well if bedrock monitoring wells had been located at several depths beneath each of the potential TCE-contributing properties. Moreover, the CSIA results show that microbial reductive dechlorination of TCE occurs in some parts of the bedrock aquifer. At this site, the use of CSIA for C and Cl in combination with analyses of VOC and redox parameters proved to be important due to the complexity introduced by

  13. Joining direct and indirect inverse calibration methods to characterize karst, coastal aquifers

    Science.gov (United States)

    De Filippis, Giovanna; Foglia, Laura; Giudici, Mauro; Mehl, Steffen; Margiotta, Stefano; Negri, Sergio

    2016-04-01

    Parameter estimation is extremely relevant for accurate simulation of groundwater flow. Parameter values for models of large-scale catchments are usually derived from a limited set of field observations, which can rarely be obtained in a straightforward way from field tests or laboratory measurements on samples, due to a number of factors, including measurement errors and inadequate sampling density. Indeed, a wide gap exists between the local scale, at which most of the observations are taken, and the regional or basin scale, at which the planning and management decisions are usually made. For this reason, the use of geologic information and field data is generally made by zoning the parameter fields. However, pure zoning does not perform well in the case of fairly complex aquifers and this is particularly true for karst aquifers. In fact, the support of the hydraulic conductivity measured in the field is normally much smaller than the cell size of the numerical model, so it should be upscaled to a scale consistent with that of the numerical model discretization. Automatic inverse calibration is a valuable procedure to identify model parameter values by conditioning on observed, available data, limiting the subjective evaluations introduced with the trial-and-error technique. Many approaches have been proposed to solve the inverse problem. Generally speaking, inverse methods fall into two groups: direct and indirect methods. Direct methods allow determination of hydraulic conductivities from the groundwater flow equations which relate the conductivity and head fields. Indirect methods, instead, can handle any type of parameters, independently from the mathematical equations that govern the process, and condition parameter values and model construction on measurements of model output quantities, compared with the available observation data, through the minimization of an objective function. Both approaches have pros and cons, depending also on model complexity. For

  14. Hydrodynamic Analysis of the Jaruco-Aguacate Aquifer; Analisis hidrodinamico del acuifero Jaurco-Aguacate

    Energy Technology Data Exchange (ETDEWEB)

    Dilla Salvador, Felix [Centro de Investigaciones Hidraulicas (Cuba)

    2002-03-01

    The paper shows the hydrodynamic analysis of the Jaruco-Aguacate aquifer using an unsteady groundwater flow mathematical model. The simulation includes conditions before and after pumping from a well filed, called El Gato, which is considered, as the most important water source for Havana city. The system is closed to the sea and conformed by an unconfined karstic aquifer with a well defined storage zone; its natural discharge flows through two spring groups. Results obtained with the model for the main spring discharge are near to the measured values, i. e. around 5 m{sup 3}/dec as the mean value for the period without main pumping station. Flow is reduced to 2.5-1.5 m{sup 3}/sec during pumping period but there are no data to confirm this result. Besides, a detailed study of the open boundary of the system is done when piezometric head variation in time is known. The mathematical modelling has been able to simulate the aquifer in its most general conception, in its regional as well as local representation, with a mean deviation of simulated head from observed values less than one meter in both analysed simulated periods. [Spanish] El objetivo del trabajo fue realizar un analisis hidrodinamico del acuifero Jaruco-Aguacate antes y despues de la puesta en marcha del acueducto el Gato, una de las fuentes de abasto mas importantes de la ciudad de La Habana, Cuba, basado en un modelo matematico de simulacion de flujo subterraneo transitorio bidimensional. El acuifero es una llanura carstica cerrada al mar y libre; hacia su centro, la zona de almacenamiento esta bien definida; el sistema de descarga natural realiza por medio de dos grupos de manantiales. El resultado obtenido para el gasto del manantial coincide con los valores aforados para un valor medio de 5 m{sup 3}/seg en el periodo analizado antes del funcionamiento del acueducto, pero su valor se reduce, variando desde 2.5 a 1.5 m{sup 3}/seg, en el periodo posterior, sin embargo, no existe informacion para

  15. Stream and aquifer biology of south-central Texas; a literature review, 1973-97

    Science.gov (United States)

    Ourso, R.T.; Hornig, C.E.

    1999-01-01

    This report summarizes in table format 32 aquatic vertebrate (primarily fish), 54 aquatic invertebrate, and 13 aquatic plant studies available for the area of the South-Central Texas study unit of the U.S. Geological Survey National Water-Quality Assessment. The studies, published mostly during 1973?97, pertain to the Guadalupe, San Antonio, and Nueces River Basins, the San Antonio-Nueces and Nueces-Rio Grande Coastal Basins, and the Edwards aquifer where it underlies the upper parts of the three river basins. The biology of the study-unit streams is determined mostly by the characteristics of the ecoregions they transect?the Edwards Plateau, Texas Blackland Prairies, East Central Texas Plains, Western Gulf Coastal Plain, and Southern Texas Plains. About 20 percent of the previous fish and invertebrate studies and about 75 percent of the aquatic plant surveys have centered on Comal Springs in Comal County and San Marcos Springs in Hays County. Although several important studies are available for the San Antonio region, documentation of aquatic biology for the remainder of the study unit is relatively sparse. The streams in the study unit, particularly in the Edwards Plateau, support three dominant biological groups?fish, aquatic invertebrates, and plants. Potential threats to these organisms include impoundments and flood-control projects, siltation from erosion, ground-water pumping, recreational activities, wastewater discharge, and introduction of non-native species. More than 30 non-native fish, invertebrate, and plant species have been introduced into the region. Of the 19 aquatic species Federally listed as endangered or threatened in Texas, 8 are associated with springs and spring runs in the study unit. All of the endangered species in the study unit are associated with springs and spring runs. A large number of endemic species in the study unit are associated with subterranean aquatic ecosystems, most likely a consequence of the unique proximity of the

  16. Geologic Setting and Hydrogeologic Units of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Kahle, Sue C.; Olsen, Theresa D.; Morgan, David S.

    2009-01-01

    The Columbia Plateau Regional Aquifer System (CPRAS) covers approximately 44,000 square miles of northeastern Oregon, southeastern Washington, and western Idaho. The area supports a $6 billion per year agricultural industry, leading the Nation in production of apples and nine other commodities (State of Washington Office of Financial Management, 2007; U.S. Department of Agriculture, 2007). Groundwater availability in the aquifers of the area is a critical water-resource management issue because the water demand for agriculture, economic development, and ecological needs is high. The primary aquifers of the CPRAS are basalts of the Columbia River Basalt Group (CRBG) and overlying basin-fill sediments. Water-resources issues that have implications for future groundwater availability in the region include (1) widespread water-level declines associated with development of groundwater resources for irrigation and other uses, (2) reduction in base flow to rivers and associated effects on temperature and water quality, and (3) current and anticipated effects of global climate change on recharge, base flow, and ultimately, groundwater availability. As part of a National Groundwater Resources Program, the U.S. Geological Survey began a study of the CPRAS in 2007 with the broad goals of (1) characterizing the hydrologic status of the system, (2) identifying trends in groundwater storage and use, and (3) quantifying groundwater availability. The study approach includes documenting changes in the status of the system, quantifying the hydrologic budget for the system, updating the regional hydrogeologic framework, and developing a groundwater-flow simulation model for the system. The simulation model will be used to evaluate and test the conceptual model of the system and later to evaluate groundwater availability under alternative development and climate scenarios. The objectives of this study were to update the hydrogeologic framework for the CPRAS using the available

  17. Large sedimentary aquifer system and sustainable management: investigations of hydrogeological and geochemical variations in Eocene sand aquifer, south western France

    Science.gov (United States)

    Malcuit, E.; Negrel, P. J.; Petelet-Giraud, E.; Durst, P.

    2010-12-01

    In the sedimentary Aquitaine Basin, the Eocene Sand Aquifer system, mostly confined, represents strategic resources for drinking water, irrigation, gas storage and geothermal resources. Therefore, its quantity and quality issues are essential for the sustainable management in this large region that extends over 116,000 km2 (i.e. one-fifth of the French territory). The Eocene Sand Aquifer system comprises at least five aquifers: Paleocene, Eocene infra-molassic sands, early Eocene, middle Eocene, and late Eocene. The extension and thickness of Eocene aquifer layers and negative confined layers vary throughout the basin, from several tens of metres to a hundred metres. The deposit sequences characterizing the Eocene Aquifer System are progradational westward from detrital deposits to carbonates. Eocene sands and Eocene limestones are hydraulically connected and covered by an aquiclude of up to several hundred metres thick of molassic sediments. The groundwater recharge is assumed to occur through the Eocene outcrops located in the north and north-east, and in the south east in contact with the Montagne Noire as well as by vertical leakage from the upper and lower aquifers. Another recharge is suspected in the south near the Petites Pyrenees. According to isotopic data, both present-day recharge and old recharge (16-35 ky) can be evidenced. The north and south evolutions of the piezometric surface are different. In the north, because of years of pumping, a trough in the potentiometric surface has been formed. The piezometric decline is roughly one meter per year in the depression centre. In the south, the decline of the water table is roughly half a meter per year. Furthermore, in the south part, around two sites of gas storage, significant fluctuations of the potentiometric surface are superimposed to the variations resulting from water abstraction, due to the injection and abstraction of gas. However, a major difficulty for the sustainable management is the lack of

  18. Hydrogeology and water quality of the Floridan aquifer system and effect of Lower Floridan aquifer pumping on the Upper Floridan aquifer at Hunter Army Airfield, Chatham County, Georgia

    Science.gov (United States)

    Clarke, John S.; Williams, Lester J.; Cherry, Gregory C.

    2010-01-01

    Test drilling and field investigations, conducted at Hunter Army Airfield (HAAF), Chatham County, Georgia, during 2009, were used to determine the geologic, hydraulic, and water-quality characteristics of the Floridan aquifer system and to evaluate the effect of Lower Floridan aquifer (LFA) pumping on the Upper Floridan aquifer (UFA). Field investigation activities included (1) constructing a 1,168-foot (ft) test boring and well completed in the LFA, (2) collecting drill cuttings and borehole geophysical logs, (3) collecting core samples for analysis of vertical hydraulic conductivity and porosity, (4) conducting flowmeter and packer tests in the open borehole within the UFA and LFA, (5) collecting depth-integrated water samples to assess basic ionic chemistry of various water-bearing zones, and (6) conducting aquifer tests in the new LFA well and in an existing UFA well to determine hydraulic properties and assess interaquifer leakage. Using data collected at the site and in nearby areas, model simulation was used to quantify the effects of interaquifer leakage on the UFA and to determine the amount of pumping reduction required in the UFA to offset drawdown resulting from the leakage. Borehole-geophysical and flowmeter data indicate the LFA at HAAF consists of limestone and dolomitic limestone between depths of 703 and 1,080 ft, producing water from six major permeable zones: 723-731; 768-785; 818-837; 917-923; 1,027-1,052; and 1,060-1,080 ft. Data from a flowmeter survey, conducted at a pumping rate of 748 gallons per minute (gal/min), suggest that the two uppermost zones contributed 469 gal/min or 62.6 percent of the total flow during the test. The remaining four zones contributed from 1.7 to 18 percent of the total flow. Grab water samples indicate that with the exception of fluoride, constituent concentrations in the LFA increased with depth; water from the deepest interval (1,075 ft) contained chloride and sulfate concentrations of 480 and 240 milligrams per

  19. The quality of our Nation's waters: water quality in the Upper Floridan aquifer and overlying surficial aquifers, southeastern United States, 1993-2010

    Science.gov (United States)

    Berndt, Marian P.; Katz, Brian G.; Kingsbury, James A.; Crandall, Christy A.

    2015-01-01

    About 10 million people rely on groundwater from the Upper Floridan and surficial aquifers for drinking water. The Upper Floridan aquifer also is of primary importance to the region as a source of water for irrigation and as a source of crystal clear water that discharges to springs and streams providing recreational and tourist destinations and unique aquatic habitats. The reliance of the region on the Upper Floridan aquifer for drinking water and for the tourism and agricultural economies highlights the importance of long-term management to sustain the availability and quality of these resources.

  20. Biodegradation of disinfection byproducts as a potential removal process during aquifer storage recovery

    Science.gov (United States)

    Landmeyer, J.E.; Bradley, P.M.; Thomas, J.M.

    2000-01-01

    The biodegradation potential of two drinking water disinfection byproducts was investigated using aquifer materials obtained from approximately 100 and 200 meters below land surface in an aerobic aquifer system undergoing aquifer storage recovery of treated surface water. No significant biodegradation of a model trihalomethane compound, chloroform, was observed in aquifer microcosms under aerobic or anaerobic conditions. In contrast, between 16 and 27 percent mineralization of a radiolabeled model haloacetic acid compound, chloroacetic acid, was observed. These results indicate that although the potential for biodegradation of chloroacetic acid exists in deep aquifer systems, chloroform entrained within these aquifers or formed in situ will tend to persist. These results have important implications for water managers planning to meet anticipated lowered permissible levels of tri-halomethanes in drinking water.The biodegradation potential of two drinking water disinfection byproducts was investigated using aquifer materials obtained from approximately 100 and 200 meters below land surface in an aerobic aquifer system undergoing aquifer storage recovery of treated surface water. No significant biodegradation of a model trihalomethane compound, chloroform, was observed in aquifer microcosms under aerobic or anaerobic conditions. In contrast, between 16 and 27 percent mineralization of a radiolabeled model haloacetic acid compound, chloroacetic acid, was observed. These results indicate that although the potential for biodegradation of chloroacetic acid exists in deep aquifer systems, chloroform entrained within these aquifers or formed in situ will tend to persist. These results have important implications for water managers planning to meet anticipated lowered permissible levels of trihalomethanes in drinking water.Aquifer-storage-recovery injection water often contains disinfection byproducts. Results are presented from a study in which two model disinfection

  1. A method to investigate inter-aquifer leakage using hydraulics and multiple environmental tracers

    Science.gov (United States)

    Priestley, Stacey; Love, Andrew; Wohling, Daniel; Post, Vincent; Shand, Paul; Kipfer, Rolf; Tyroller, Lina

    2016-04-01

    Informed aquifer management decisions regarding sustainable yields or potential exploitation require an understanding of the groundwater system (Alley et al. 2002, Cherry and Parker 2004). Recently, the increase in coal seam gas (CSG) or shale gas production has highlighted the need for a better understanding of inter-aquifer leakage and contaminant migration. In most groundwater systems, the quantity or location of inter-aquifer leakage is unknown. Not taking into account leakage rates in the analysis of large scale flow systems can also lead to significant errors in the estimates of groundwater flow rates in aquifers (Love et al. 1993, Toth 2009). There is an urgent need for robust methods to investigate inter-aquifer leakage at a regional scale. This study builds on previous groundwater flow and inter-aquifer leakage studies to provide a methodology to investigate inter-aquifer leakage in a regional sedimentary basin using hydraulics and a multi-tracer approach. The methodology incorporates geological, hydrogeological and hydrochemical information in the basin to determine the likelihood and location of inter-aquifer leakage. Of particular benefit is the analysis of hydraulic heads and environmental tracers at nested piezometers, or where these are unavailable bore couplets comprising bores above and below the aquitard of interest within a localised geographical area. The proposed methodology has been successful in investigating inter-aquifer leakage in the Arckaringa Basin, South Australia. The suite of environmental tracers and isotopes used to analyse inter-aquifer leakage included the stable isotopes of water, radiocarbon, chloride-36, 87Sr/86Sr and helium isotopes. There is evidence for inter-aquifer leakage in the centre of the basin ~40 km along the regional flow path. This inter-aquifer leakage has been identified by a slight draw-down in the upper aquifer during pumping in the lower aquifer, overlap in Sr isotopes, δ2H, δ18O and chloride

  2. Initial In-situ Hydrologic Measurements of the Greenland Perennial Firn Aquifer

    Science.gov (United States)

    Miller, O. L.; Solomon, D. K.; Miège, C.; Koenig, L.; Schmerr, N. C.; Montgomery, L. N.; Legchenko, A.; Forster, R. R.

    2015-12-01

    Widespread storage of meltwater within the compacting snow (firn) in the southeastern region of the Greenland ice sheet exists throughout the year. The water saturated firn (~10-30 m below the snow surface) extends to an average depth of 20 m and overlays the firn-ice transition. The aquifer resides mainly within the percolation zone at elevations between 1200 and 2000 m, in areas of high snow accumulation. Depth specific hydrologic measurements in several boreholes within the Greenland ice sheet firn aquifer are used to understand water recharge, transport, and discharge, as well as the aquifer's relationship with the broader englacial drainage system. Measurements within the aquifer (~20-30 m below the snow surface) include hydraulic conductivity, water levels, and environmental tracer concentrations in the liquid water (tritium, CFCs, and noble gasses). Tritium concentration profiles (from the surface to ~50 m depth) were also measured in firn core above, within, and below the aquifer. Similarities and differences to land-based groundwater aquifers are observed. Slug and aquifer pumping tests indicate high hydraulic conductivity (~10-4 m/s). Water samples show minor differences in tritium variation with depth and larger difference in dissolved noble gasses with depth. Tritium concentrations at depth in water and firn are similar to each other but differ from predicted concentrations based on a core-derived firn depth-age model and tritium decay. CFC concentrations are lower than atmospheric solubility. Tritium and CFC results suggest that exchange between liquid water and the atmosphere is very different in this firn aquifer than a conventional groundwater aquifer. These first of their kind measurements taken from the Greenland perennial firn aquifer contribute to our understanding of aquifer behavior and it's relation to regional ice-sheet dynamics and contribution to sea-level rise.

  3. Predictability, stationarity, and classification of hydraulic responses to recharge in two karst aquifers

    Directory of Open Access Journals (Sweden)

    A. J. Long

    2012-08-01

    Full Text Available Karst aquifers, many of which are rapidly filled and depleted, are likely to be highly susceptible to changes in short-term climate variability. Here we explore methods that could be applied to model site-specific hydraulic responses, with the intent of simulating these responses to different climate scenarios from high-resolution climate models. We compare hydraulic responses (spring flow, groundwater level, and stream base flow at several sites in two karst aquifers: the Edwards aquifer (Texas, USA and the Madison aquifer (South Dakota, USA. A one-dimensional, lumped-parameter model simulates nonstationary soil moisture changes for estimation of recharge, and a nonstationary convolution model simulates the aquifer response to this recharge. Model fit to data was 4% better for calibration periods than for validation periods. We use metrics that describe the shapes of the impulse-response functions (IRFs obtained from convolution modeling to make comparisons in the distribution of response times among sites and among aquifers. Combined principal component analysis and cluster analysis of metrics describing the shapes of the IRFs separated those sites with IRFs having a large ratio of the mean response time to the system memory from those with large skewness and kurtosis. Classification of the IRF metrics indicate that there is a range of IRF characteristics for different site types (i.e., spring flow, groundwater level, base flow within a karst system. Further, similar site types did not necessarily display similar IRFs. Results indicate that the differences existing within either aquifer are larger than the differences between the two aquifers and that the two aquifers are similar according to this classification. The use of multiple metrics to describe the IRFs provides a novel way to characterize and compare the way in which multiple sites respond to recharge. As convolution models are developed for additional aquifers, they could contribute

  4. Studying the impact of climate change on coastal aquifers and adjacent wetlands

    Science.gov (United States)

    Stigter, Tibor; Ribeiro, Luís.; Oliveira, Rodrigo; Samper, Javier; Fakir, Younes; Fonseca, Luís.; Monteiro, José Paulo; Nunes, João. Pedro; Pisani, Bruno

    2010-05-01

    negligible, groundwater recharge is determined by evapotranspiration methods. WP3 involves the monitoring and modeling of groundwater. Water level, electrical conductivity (EC) and temperature measurements are made on a regular basis. At the Portuguese study site, continuous recording of these parameters is performed in the estuary and adjacent aquifer, studying the effect of tidal fluctuations and seasonal variations in recharge and abstractions. Groundwater flow and transport models are created or further developed, integrating the climate scenarios and recharge calculations of WP2, in order to simulate the impact on aquifer hydrodynamics and the movement of the fresh/salt water interface. In WP4 the response of coastal ecosystems to changes in groundwater inputs is assessed with the aid of ecological diversity indices and by using particular taxonomic groups of invertebrates as bioindicators. Mesofauna groups are also characterized in groundwater and their potential as indicators of changes in water composition is assessed. Preliminary results at the Portuguese study site allow understanding that low salinity is apparently relevant for the colonization of the macroinvertebrate species in the groundwater receiving wetland, as the typically estuarine species, which tolerate low salinity, are abundant.

  5. Combining lead isotopes and cluster analysis to distinguish the Guarani and Serra Geral Aquifer Systems and contaminated waters in a highly industrialized area in Southern Brazil.

    Science.gov (United States)

    Kuhn, Isadora Aumond; Roisenberg, Ari

    2017-10-01

    The Rio dos Sinos Watershed area is located at the Middle-West region of the Rio Grande do Sul State, Southern Brazil, along thirty two municipalities and affecting 1.5 million inhabitants and many important industrial centers. Three main aquifers are recognized in the study area: the unconfined-fractured Serra Geral Aquifer System, the porous Guarani Aquifer System, and the Permian Aquitard. This study aims to understand groundwater, surface water and human activity interactions in the Rio dos Sinos Watershed, evaluating the application of stable lead isotopic ratios analyzed for this propose. Thirty six groundwater samples, 8 surface water samples and 5 liquid effluents of tanneries and landfills samples were measured using a Thermal Ionization Mass Spectrometer Thermo-Finnigan and a Neptune Multi-Collector Inductively Coupled Plasma Mass Spectrometer. Groundwater isotopic ratios have a wider range compared to the surface water, with less radiogenic averages (208)Pb/(204)Pb = 38.1837 vs 38.4050 (standard deviation = 0.2921 vs 0.1343) and (206)Pb/(204)Pb = 18.2947 vs 18.4766 (standard deviation = 0.2215 vs 0.1059), respectively. Industrial liquid effluents (tanneries and industrial landfill) have averages (208)Pb/(204)Pb = 38.1956 and (206)Pb/(204)Pb = 18.3169, distinct from effluent samples of domestic sanitary landfill (averages (208)Pb/(204)Pb = 38.2353 and (206)Pb/(204)Pb = 18.6607). Hierarchical cluster analysis led to distinguish six groups of groundwater, representing the three aquifers that occur in the area, two clusters suggesting groundwater mixtures and one demonstrating a highly contaminated groundwater. By analyzing the cluster results and wells' stratigraphic profiles it was possible to distinguish the different aquifers in the area. The Serra Geral Aquifer System has (206)Pb/(204)Pb ratios between 18.4718 and 18.7089; (207)Pb/(204)Pb between 15.6692 and 15.6777; (208)Pb/(204)Pb between 38.6826 and 38.7616; (207)Pb/(206)Pb between 0

  6. Groundwater-flow model and effects of projected groundwater use in the Ozark Plateaus Aquifer System in the vicinity of Greene County, Missouri - 1907-2030

    Science.gov (United States)

    Richards, Joseph M.

    2010-01-01

    the aquifer in relatively short periods of time. Pumpage rates in the model area increased from 1,093,268 cubic feet per day in 1962 to 2,693,423 cubic feet per day in 1987 to 4,330,177 cubic feet per day in 2006. Annual precipitation ranged from 25.21 inches in 1953 to 62.45 inches in 1927 from 1915 to 2006 in the model area. Recharge to the model was calculated as 2.53 percent of the annual precipitation and was varied annually. Recharge was distributed over the model area based on land slope and was adjusted in the city limits of Springfield to account for the impervious surface. A groundwater model with annual stress periods from 1907 to 2030 was developed using a transient calibration period from 1987 to 2006 and a prediction period from 2007 to 2030 to simulate flow in the Springfield Plateau aquifer and the Ozark aquifer. For the model area of approximately 2,870 square miles, the model hydrogeologic units and hydraulic properties were discretized into 253 rows, 316 columns, and 3 layers with the layer boundaries crossing hydrogeologic unit boundaries in some areas. The horizontal cell spacing was 1,000 feet by 1,000 feet. The model was calibrated by minimizing the difference between simulated head and observed water levels and simulated and observed flows in rivers and springs. Population and the associated groundwater use were estimated for 12 communities and the unincorporated area of Greene County based on past growth. Each was analyzed individually, and a low and high annual rate of growth relative to the 2006 population was computed for each community or group. Low growth rates ranged from 0.215 percent per year in Springfield to 6.997 percent per year in Rogersville. Total growth from 2006 to 2030 at the low growth rate ranged from 5.2 percent in Springfield to 167.9 percent in Rogersville. High growth rates ranged from 0.236 percent per year in Springfield to 7.345 percent per year in Rogersville. Total growth from 2006 to 2030 at the high g

  7. Mineralization Of PAHs In Coal-Tar Impacted Aquifer Sediments And Associated Microbial Community Structure Investigated With FISH

    Science.gov (United States)

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detect...

  8. Cost-Benefit Analysis of the Managed Aquifer Recharge System for Irrigation under Climate Change Conditions in Southern Spain

    National Research Council Canada - National Science Library

    Carmen Ruperez-Moreno; Julio Perez-Sanchez; Javier Senent-Aparicio; Pilar Flores-Asenjo; Carmen Paz-Aparicio

    2017-01-01

    .... In the integrated water resource management (IWRM), managed aquifer recharge (MAR) offers efficient solutions to protect, conserve, and ensure survival of aquifers and associated ecosystems, as the Water Framework Directive requires...

  9. Effects of aquifer storage and recovery activities on water quality in the Little Arkansas River and Equus Beds Aquifer, south-central Kansas, 2011–14

    Science.gov (United States)

    Stone, Mandy L.; Garrett, Jessica D.; Poulton, Barry C.; Ziegler, Andrew C.

    2016-07-18

    The Equus Beds aquifer in south-central Kansas is aprimary water source for the city of Wichita. The Equus Beds aquifer storage and recovery (ASR) project was developed to help the city of Wichita meet increasing current (2016) and future water demands. The Equus Beds ASR project pumps water out of the Little Arkansas River during above-base flow conditions, treats it using drinking-water quality standards as a guideline, and recharges it into the Equus Beds aquifer for later use. Phase II of the Equus Beds ASR project currently (2016) includes a river intake facility and a surface-water treatment facility with a 30 million gallon per day capacity. Water diverted from the Little Arkansas River is delivered to an adjacent presedimentation basin for solids removal. Subsequently, waste from the surface-water treatment facility and the presedimentation basin is returned to the Little Arkansas River through a residuals return line. The U.S. Geological Survey, in cooperation with the city of Wichita, developed and implemented a hydrobiological monitoring program as part of the ASR project to characterize and quantify the effects of aquifer storage and recovery activities on the Little Arkansas River and Equus Beds aquifer water quality.Data were collected from 2 surface-water sites (one upstream and one downstream from the residuals return line), 1 residuals return line site, and 2 groundwater well sites (each having a shallow and deep part): the Little Arkansas River upstream from the ASR facility near Sedgwick, Kansas (upstream surface-water site 375350097262800), about 0.03 mile (mi) upstream from the residuals return line site; the Little Arkansas River near Sedgwick, Kans. (downstream surface-water site 07144100), about 1.68 mi downstream from the residuals return line site; discharge from the Little Arkansas River ASR facility near Sedgwick, Kansas (residuals return line site 375348097262800); 25S 01 W 07BCCC01 SMW–S11 near CW36 (MW–7 shallow groundwater well

  10. Evaluating the role of large earthquakes on aquifer dynamics using data fusion and knowledge discovery techniques

    Science.gov (United States)

    Friedel, Michael; Cox, Simon; Williams, Charles; Holden, Caroline

    2016-04-01

    Artificial adaptive systems are evaluated for their usefulness in modeling earthquake hydrology of the Canterbury region, NZ. For example, an unsupervised machine-learning technique, self-organizing map, is used to fuse about 200 disparate and sparse data variables (such as, well pressure response, ground acceleration, intensity, shaking, stress and strain; aquifer and well characteristics) associated with the M7.1 Darfield earthquake in 2010 and the M6.3 Christchurch earthquake in 2011. The strength of correlations, determined using cross-component plots, varied between earthquakes with pressure changes more strongly related to dynamic- than static stress-related variables during the M7.1 earthquake, and vice versa during the M6.3. The method highlights the importance of data distribution and that driving mechanisms of earthquake-induced pressure change in the aquifers are not straight forward to interpret. In many cases, data mining revealed that confusion and reduction in correlations are associated with multiple trends in the same plot: one for confined and one for unconfined earthquake response. The autocontractive map and minimum spanning tree techniques are used for grouping variables of similar influence on earthquake hydrology. K-means clustering of neural information identified 5 primary regions influenced by the two earthquakes. The application of genetic doping to a genetic algorithm is used for identifying optimal subsets of variables in formulating predictions of well pressures. Predictions of well pressure changes are compared and contrasted using machine-learning network and symbolic regression models with prediction uncertainty quantified using a leave-one-out cross-validation strategy. These preliminary results provide impetus for subsequent analysis with information from another 100 earthquakes that occurred across the South Island.

  11. Regional Risk Assessment for climate change impacts on coastal aquifers.

    Science.gov (United States)

    Iyalomhe, F; Rizzi, J; Pasini, S; Torresan, S; Critto, A; Marcomini, A

    2015-12-15

    Coastal aquifers have been identified as particularly vulnerable to impacts on water quantity and quality due to the high density of socio-economic activities and human assets in coastal regions and to the projected rising sea levels, contributing to the process of saltwater intrusion. This paper proposes a Regional Risk Assessment (RRA) methodology integrated with a chain of numerical models to evaluate potential climate change-related impacts on coastal aquifers and linked natural and human systems (i.e., wells, river, agricultural areas, lakes, forests and semi-natural environments). The RRA methodology employs Multi Criteria Decision Analysis methods and Geographic Information Systems functionalities to integrate heterogeneous spatial data on hazard, susceptibility and risk for saltwater intrusion and groundwater level variation. The proposed approach was applied on the Esino River basin (Italy) using future climate hazard scenarios based on a chain of climate, hydrological, hydraulic and groundwater system models running at different spatial scales. Models were forced with the IPCC SRES A1B emission scenario for the period 2071-2100 over four seasons (i.e., winter, spring, summer and autumn). Results indicate that in future seasons, climate change will cause few impacts on the lower Esino River valley. Groundwater level decrease will have limited effects: agricultural areas, forests and semi-natural environments will be at risk only in a region close to the coastline which covers less than 5% of the total surface of the considered receptors; less than 3.5% of the wells will be exposed in the worst scenario. Saltwater intrusion impact in future scenarios will be restricted to a narrow region close to the coastline (only few hundred meters), and thus it is expected to have very limited effects on the Esino coastal aquifer with no consequences on the considered natural and human systems.

  12. Impact of aquifer desaturation on steady-state river seepage

    Science.gov (United States)

    Morel-Seytoux, Hubert J.; Miracapillo, Cinzia; Mehl, Steffen

    2016-02-01

    Flow exchange between surface and ground water is of great importance be it for beneficial allocation and use of the water resources or for the proper exercise of water rights. That exchange can take place under a saturated or unsaturated flow regime. Which regimes occur depend on conditions in the vicinity of the interactive area. Withdrawals partially sustained by seepage may not bring about desaturation but greater amounts eventually will. The problem considered in this paper deals only with the steady-state case. It is meant as a first step toward a simple, yet accurate and physically based treatment of the transient situation. The primary purpose of the article is to provide simple criteria for determination of the initiation of desaturation in an aquifer originally in saturated hydraulic connection with a river or a recharge area. The extent of the unsaturated zone in the aquifer will increase with increasing withdrawals while at the same time the seepage rate from the river increases. However the seepage increase will stop once infiltration takes place strictly by gravity in the aquifer and is no longer opposed by the capillary rise from the water table below the riverbed. Following desaturation simple criteria are derived and simple analytical formulae provided to estimate the river seepage based on the position of the water table mound below the clogging layer and at some distance away from the river bank. They fully account for the unsaturated flow phenomena, including the existence of a drainage entry pressure. Two secondary objectives were to verify that (1) the assumption of uniform vertical flow through a clogging layer and that (2) the approximation of the water table mound below the seepage area as a flat surface were both reasonably legitimate. This approach will be especially advantageous for the implementation of the methodology in large-scale applications of integrated hydrologic models used for management.

  13. Deep aquifer prokaryotic community responses to CO2 geosequestration

    Science.gov (United States)

    Mu, A.; Moreau, J. W.

    2015-12-01

    Little is known about potential microbial responses to supercritical CO2 (scCO2) injection into deep subsurface aquifers, a currently experimental means for mitigating atmospheric CO2 pollution being trialed at several locations around the world. One such site is the Paaratte Formation of the Otway Basin (~1400 m below surface; 60°C; 2010 psi), Australia. Microbial responses to scCO2 are important to understand as species selection may result in changes to carbon and electron flow. A key aim is to determine if biofilm may form in aquifer pore spaces and reduce aquifer permeability and storage. This study aimed to determine in situ, using 16S rRNA gene, and functional metagenomic analyses, how the microbial community in the Otway Basin geosequestration site responded to experimental injection of 150 tons of scCO2. We demonstrate an in situ sampling approach for detecting deep subsurface microbial community changes associated with geosequestration. First-order level analyses revealed a distinct shift in microbial community structure following the scCO2 injection event, with proliferation of genera Comamonas and Sphingobium. Similarly, functional profiling of the formation revealed a marked increase in biofilm-associated genes (encoding for poly-β-1,6-N-acetyl-D-glucosamine). Global analysis of the functional gene profile highlights that scCO2 injection potentially degraded the metabolism of CH4 and lipids. A significant decline in carboxydotrophic gene abundance (cooS) and an anaerobic carboxydotroph OTU (Carboxydocella), was observed in post-injection samples. The potential impacts on the flow networks of carbon and electrons to heterotrophs are discussed. Our findings yield insights for other subsurface systems, such as hydrocarbon-rich reservoirs and high-CO2 natural analogue sites.

  14. Potential Risks of Freshwater Aquifer Contamination with Geosequestration

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Robert

    2013-09-30

    Substantial leakage of CO{sub 2} from deep geological strata to shallow potable aquifers is likely to be rare, but chemical detection of potential leakage nonetheless remains an integral component of any safe carbon capture and storage system. CO{sub 2} that infiltrates an unconfined freshwater aquifer will have an immediate impact on water chemistry by lowering pH in most cases and by altering the concentration of total dissolved solids. Chemical signatures in affected waters provide an important opportunity for early detection of leaks. In the presence of CO{sub 2}, trace elements such as Mn, Fe, and Ca can increase by an order of magnitude or more above control concentrations within 100 days. Therefore, these and other elements should be monitored along with pH as geochemical markers of potential CO{sub 2} leaks. Dissolved inorganic carbon and alkalinity can also be rapidly responsive to CO{sub 2} and are stable indicators of a leak. Importantly, such changes may be detectable long before direct changes in CO{sub 2} are observed. The experimental results also suggest that the relative severity of the impact of leaks on overlying drinking-water aquifers should be considered in the selection of CO{sub 2} sequestration sites. One primary selection criteria should be metal and metalloid availability, such as uranium and arsenic abundance, to carefully monitor chemical species that could trigger changes above maximum contaminant levels (MCLs). Overall, the risks of leakage from underground CO{sub 2} storage are real but appear to be manageable if systems are closely monitored.

  15. Reflection seismic imaging of shallow aquifers in Milano (northern Italy)

    Science.gov (United States)

    Francese, R.; Zaja, A.; Giudici, M.; Schmitt, D.

    2003-04-01

    A high resolution P-wave seismic reflection survey was conducted in the Lambro park within the city of Milano (northern Italy). The objective of the survey was to image structure and stratigraphy of shallow late tertiary and quaternary deposits. This information is necessary to develop a comprehensive 3D hydrological model of the fresh water aquifers where the municipality drilled several production wells. The expected complexity of the acoustic framework and the urban environment with its complications created a challenging test site for the reflection technique. The aquifer system was targeted with a 2-D high resolution seismic reflection survey to outline its vertical and lateral dimensions to a depth of 150-200 m and to estimate some petrophysical properties of the depositional units. A 0.8-km CMP seismic line, with 1-m station spacing, was deployed to collect reflection data. The recording geometry was a 240-channel split spread array, with 6-m shot separation, resulting in a maximum of 20-fold dataset. A single 40-Hz geophone at each station location detected the incoming signals. Field records exhibit clear reflections although the signal to noise ratio is poor because of strong surface waves and severe disturbances from the nearby highway. Optimized FK and KL transforms were used to attenuate these coherent noises and to enhance the primary reflections from the main horizons. The data analysis was also assisted by forward modeling to guide the selection of the processing parameters. The seismic data have a good correlation thourhgout the section and most of the acoustic units show flat bedding. The boundaries of the three major depositional units are clearly resolved by the seismic images. The stacked section clearly indicates that reflection technique provides a powerful method to characterize aquifers, even in a very noisy environment like the urban areas.

  16. Fundamental quantitative analysis of microbial activity in aquifer bioreclamation

    Energy Technology Data Exchange (ETDEWEB)

    Rittmann, B.E.; Valocchi, A.J. (Illinois Univ., Urbana, IL (USA). Dept. of Civil Engineering); Baveye, P. (Cornell Univ., Ithaca, NY (USA). Dept. of Agronomy)

    1990-01-01

    Research continued on aquifer bioreclamation. The project has four primary areas: (1) biodegradation of poorly soluble organic contaminants, (2) dual-limitation kinetics of electron donors and acceptors, (3) two-dimensional modeling of biofilm reactions in nonhomogeneous porous media, and (4) biologically induced clogging in porous media. For each area, this report gives a brief summary of the first year's progress, report this quarter's progress in detail, and indicate plans for future work. 25 refs., 10 figs., 14 tabs.

  17. Fluid Dynamics of Carbon Dioxide Disposal into Saline Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Julio Enrique

    2003-12-18

    Injection of carbon dioxide (CO{sub 2}) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). Large-scale injection of CO{sub 2} will induce a variety of coupled physical and chemical processes, including multiphase fluid flow, fluid pressurization and changes in effective stress, solute transport, and chemical reactions between fluids and formation minerals. This work addresses some of these issues with special emphasis given to the physics of fluid flow in brine formations. An investigation of the thermophysical properties of pure carbon dioxide, water and aqueous solutions of CO{sub 2} and NaCl has been conducted. As a result, accurate representations and models for predicting the overall thermophysical behavior of the system CO{sub 2}-H{sub 2}O-NaCl are proposed and incorporated into the numerical simulator TOUGH2/ECO{sub 2}. The basic problem of CO{sub 2} injection into a radially symmetric brine aquifer is used to validate the results of TOUGH2/ECO2. The numerical simulator has been applied to more complex flow problem including the CO{sub 2} injection project at the Sleipner Vest Field in the Norwegian sector of the North Sea and the evaluation of fluid flow dynamics effects of CO{sub 2} injection into aquifers. Numerical simulation results show that the transport at Sleipner is dominated by buoyancy effects and that shale layers control vertical migration of CO{sub 2}. These results are in good qualitative agreement with time lapse surveys performed at the site. High-resolution numerical simulation experiments have been conducted to study the onset of instabilities (viscous fingering) during injection of CO{sub 2} into saline aquifers. The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO{sub 2}) the viscosity of carbon dioxide can be less than the viscosity of the aqueous

  18. Denitrification in a BTEX Contaminated Aquifer Containing Reduced Sulfur

    Science.gov (United States)

    Eckert, P.; Appelo, C.; Wisotzky, F.; Obermann, P.

    2001-05-01

    At a former gasworks plant in Duesseldorf (Germany) a massive soil and groundwater contamination with BTEX (up to 100 mg/l) and to a minor extent with PAH (up to 10 mg/l) were detected. Mainly due to sulfate and iron-(III) reduction, a natural biodegradation has occurred and restricted the length of the contaminant plume in the direction of groundwater flow to only 600 m. The active remediation strategy at this site includes nitrate-enhanced in-situ bioremediation of the remaining contaminants in the plume. Nitrate was infiltrated in the contaminated aquifer during a field test to study the efficacy of enhanced natural attenuation. Degradation of hydrocarbons under denitrifying has been proved by numerous laboratory and field studies. However, at this site the competing reaction of nitrate with hydrocarbons and reduced sulfur components has to be considered. The oxidation of pyrite by nitrate in pristine aquifers is well known. The Duesseldorf aquifer contains FeS, pyrite and Fe-calcite precipitated during over 50 years of natural attenuation. The hydrogeochemical transport model PHREEQC-2 is used to simulate the distribution of chemical species and reaction rates along the flow path between the infiltration well and two multilevel wells . The complicated suite of reactions caused by the reduction of nitrate is evaluated by the comparison of modeled and measured data. At the Duesseldorf site the concomitant presence of nitrate, Fe(II) and BTEX/PAHs showed that the reactions did not evolve to thermodynamic equilibrium and were controlled by kinetics. The very good fit of observed and model calculations illustrates that the inorganic chemical reactions during the field test are generally well understood. The kinetic reactions could be modelled with rate equations from the literature based on oxygen, and which were extended with nitrate. Denitrification rates with BTEX compounds and with FeS were found to be comparable, but the oxidation of Fe(II) and FeS occurred

  19. Physical and numerical modeling of seawater intrusion in coastal aquifers

    Science.gov (United States)

    Crestani, Elena; Camporese, Matteo; Salandin, Paolo

    2016-04-01

    Seawater intrusion in coastal aquifers is a worldwide problem caused, among others factors, by aquifer overexploitation, rising sea levels, and climate changes. To limit the deterioration of both surface water and groundwater quality caused by saline intrusion, in recent years many research studies have been developed to identify possible countermeasures, mainly consisting of underground barriers. In this context, physical models are fundamental to study the saltwater intrusion, since they provide benchmarks for numerical model calibrations and for the evaluation of the effectiveness of general solutions to contain the salt wedge. This work presents a laboratory experiment where seawater intrusion was reproduced in a specifically designed sand-box. The physical model, built at the University of Padova, represents the terminal part of a coastal aquifer and consists of a flume 500 cm long, 30 cm wide and 60 cm high, filled for an height of 49 cm with glass beads characterized by a d50 of 0.6 mm and a uniformity coefficient d60/d10 ≈ 1.5. The resulting porous media is homogeneous, with porosity of about 0.37 and hydraulic conductivity of about 1.3×10-3 m/s. Upstream from the sand-box, a tank filled by freshwater provides the recharge to the aquifer. The downstream tank simulates the sea and red food dye is added to the saltwater to easily visualize the salt wedge. The volume of the downstream tank is about five times the upstream one, and, due to the small filtration discharge, salt concentration variations (i.e., water density variations) due to the incoming freshwater flow are negligible. The hydraulic gradient during the tests is constant, due to the fixed water level in the two tanks. Water levels and discharged flow rate are continuously monitored. The experiment presented here had a duration of 36 h. For the first 24 h, the saltwater wedge was let to evolve until quasi stationary condition was obtained. In the last 12 h, water withdrawal was carried out at a

  20. A Microbiological Water Quality Evaluation of Ganges River Deltaic Aquifers

    Science.gov (United States)

    Yerby, C. J.; Gragg, S. E.; Page, J.; Leavens, J.; Bhattacharya, P.; Harrington, J.; Datta, S.

    2014-12-01

    Substantial natural contamination from trace elements (like arsenic) and pathogens make Ganges Deltaic aquifers an area of utmost concern. Following millions of cases of chronic arsenic poisoning from the groundwaters of the region, numerous residents are still knowingly ingesting water from shallow to intermediate accessible depth drinking water wells. Added to the calamity of arsenic is the prevalence of pathogenic bacteria in these waters. The increasing frequency of gastroenteritis signifies the need to quantify the magnitude and extensiveness of health degrading agents--bacterial pathogens (i.e. Salmonella) and non-pathogens (i.e. Enterobacteriaceae) --within the water supply in accessible Gangetic aquifers. To assess the dissolved microbiological quality in the region, present study sampling locations are along defined piezometer nests in an area in SE Asia (Bangladesh). Every nest contains samples from wells at varying depths covering shallow to deep aquifers. To date, 17 of the 76 water samples were analyzed for Salmonella, generic Escherichia coli (E. coli) and coliforms. Briefly, samples were plated in duplicate onto E. coli/Coliform petrifilm and incubated at 370C for 48 hours. Next, each sample was enriched in buffered peptone water and incubated at 370C for 18 hours. Bacterial DNA was extracted and amplified using a qPCR machine. Amplification plots were analyzed to determine presence/absence of microorganisms. All water samples (n=~76) are analyzed for Salmonella, Escherichia coli O157:H7, Listeria spp. and Shigella. Pathogen populations of PCR-positive water samples are enumerated using the agar direct plate method. Non-pathogenic bacterial indicator organisms (i.e. Enterobacteriaceae) will also be enumerated. Over the course of the experiment, we hypothesize that shallower wells will 1)have a higher pathogen prevalence and 2)harbor pathogens and nonpathogens at higher concentrations. While the 17 samples analyzed to date were negative for Salmonella

  1. Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

    Science.gov (United States)

    Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

    2017-04-01

    Aquifer Thermal Energy Storage (ATES) systems allow storing large quantities of thermal energy in subsurface aquifers enabling significant energy savings and greenhouse gas reductions. This is achieved by injection and extraction of water into and from saturated underground aquifers, simultaneously. An ATES system consists of two wells and operates in a seasonal mode. One well is used for the storage of cold water, the other one for the storage of heat. In warm seasons, cold water is extracted from the cold well to provide cooling to a building. The temperature of the extracted cold water increases as it passes through the building climate control systems and then gets simultaneously, injected back into the warm well. This procedure is reversed during cold seasons where the flow direction is reversed such that the warmer water is extracted from the warm well to provide heating to a building. From the perspective of building climate comfort systems, an ATES system is considered as a seasonal storage system that can be a heat source or sink, or as a storage for thermal energy. This leads to an interesting and challenging optimal control problem of the building climate comfort system that can be used to develop a seasonal-based energy management strategy. In [1] we develop a control-oriented model to predict thermal energy balance in a building climate control system integrated with ATES. Such a model however cannot cope with off-nominal but realistic situations such as when the wells are completely depleted, or the start-up phase of newly installed wells, etc., leading to direct usage of aquifer ambient temperature. Building upon our previous work in [1], we here extend the mathematical model for ATES system to handle the above mentioned more realistic situations. Using our improved models, one can more precisely predict system behavior and apply optimal control strategies to manage the building climate comfort along with energy savings and greenhouse gas reductions

  2. Methodology for rapid assessment of aquifer recharge areas

    Directory of Open Access Journals (Sweden)

    Vitor Vieira Vasconcelos

    2013-06-01

    Full Text Available The environmental tools of local appliance, such as surveillance and permits of deforestations and water use, environmentalimpact assessments of local scale, and delimitation of preservation areas, demand customized methodologies to deal withhydrogeological issues. In this study, a structured one for rapid environmental assessment aiming at recharge of aquiferssafety was presented. This comprises qualitative and quantitative evaluations by means of textual and cartographicaldescriptions, complemented by weighted spreadsheets for rapid assessment. Applications in case studies took place in sitesselected in the Paracatu River Basin. The results showed a positive potential for knowledge and protection of aquifers inmicro-watersheds.

  3. Biodegradation of alkylates under less agitated aquifer conditions

    Institute of Scientific and Technical Information of China (English)

    Jay J.Cho; Makram T.Suidan; Albert D.Venosa

    2013-01-01

    The biodegradability of three alkylates (2,3-dimethylpentane,2,4-dimethylpentane and 2,2,4-trimethylpentane) under less agitated aquifer conditions was investigated in this study.All three alkylates biodegraded completely under these conditions regardless of the presence or absence of ethanol or benzene,toluene,ethylbenzene,and xylenes (BTEX) in the feed.In the presence of ethanol,alkylates degradation was not inhibited by ethanol.However,alkylates degraded more slowly in the presence of BTEX suggesting competitive inhibition to microbial utilization of alkylates.In the sterile controls,alkylates concentrations remained unchanged throughout the experiments.

  4. Large-Scale Experiments in a Sandy Aquifer in Denmark

    DEFF Research Database (Denmark)

    Jensen, Karsten Høgh; Bitsch, Karen Bue; Bjerg, Poul Løgstrup

    1993-01-01

    vertical directions was very small. The horizontal transport parameters of the advection-dispersion equation were investigated by applying an optimization model to observed breakthrough curves of tritium representing depth averaged concentrations. No clear trend in dispersion parameters with travel...... distance for distances between 50 and 200 m could be found, suggesting that the asymptotic stage was reached within a short distance from the point of injection. A three-dimensional numerical model for flow and transport was applied to the aquifer in order to quantify the dispersivity parameters more...

  5. Historical potentiometric surface of the Edwards-Trinity aquifer system and contiguous hydraulically connected units, west-central Texas

    Science.gov (United States)

    Bush, Peter W.; Ardis, Ann F.; Wynn, Kirby H.

    1993-01-01

    The Edwards-Trinity aquifer system is a sequence of near-surface, hydraulically connected, Cretaceous carbonate and quartzose clastic rocks that underlie about 42,000 mi2 of west-central Texas (fig. 1). The aquifer system is currently (1991) being studied as a part of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program, which is intended to describe the regional hydrogeology of important aquifer systems nationwide.

  6. Temporal variations in water quality of the Ogallala Aquifer on the Texas High Plains

    Science.gov (United States)

    The Ogallala Aquifer, under eight States of the Great Plains of US, from Texas to South Dakota, is among the largest aquifers in the world. In some regions, extraction of water for urban and agricultural uses far exceeds recharge resulting in a decline of the water table. In the southern region of t...

  7. Using Genetic Algorithm and MODFLOW to Characterize Aquifer System of Northwest Florida (Published Proceedings)

    Science.gov (United States)

    By integrating Genetic Algorithm and MODFLOW2005, an optimizing tool is developed to characterize the aquifer system of Region II, Northwest Florida. The history and the newest available observation data of the aquifer system is fitted automatically by using the numerical model c...

  8. Using Genetic Algorithm and MODFLOW to Characterize Aquifer System of Northwest Florida

    Science.gov (United States)

    By integrating Genetic Algorithm and MODFLOW2005, an optimizing tool is developed to characterize the aquifer system of Region II, Northwest Florida. The history and the newest available observation data of the aquifer system is fitted automatically by using the numerical model c...

  9. Applications of universal kriging to an aquifer study in New Jersey

    Science.gov (United States)

    Pucci, A.A.; Murashige, J.A.E.

    1987-01-01

    Describes the use of kriging for optimizing data collection and utility in a regional groundwater investigation of the Potomac-Raritan-Magothy aquifer system in central New Jersey, Kriging was used to 1) estimate the altitude of an aquifer surface, 2) estimate hydraulic conductivities from point data, and 3) estimate the associated kriged errors. -from Authors

  10. 40 CFR Appendix A to Subpart Hhh... - Exempted Aquifers in New Mexico

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Exempted Aquifers in New Mexico A Appendix A to Subpart HHH of Part 147 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Appendix A to Subpart HHH of Part 147—Exempted Aquifers in New Mexico The areas described by a...

  11. Potential for Siting New Water Wells and Restoring Existing Wells in Arsenic-Impacted Aquifers

    Science.gov (United States)

    Studies have indicated that arsenic concentrations greater than the new U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) concentration of 10 micrograms per liter (ug/L) occur in numerous aquifers around the United States. One such aquifer is the Central ...

  12. Use of stable isotope-labeled Escherichia coli as a tracer in karst aquifers

    Science.gov (United States)

    Bacterial contamination of karst aquifers is a large concern across the globe, yet bacterial transport in karst aquifers is not currently well understood. Groundwater tracers typically used in karst systems include fluorescent dyes and latex microspheres. Not only can these tracers can be cost-prohi...

  13. Regional assessment of aquifers for thermal energy storage. Volume 1. Regions 1 through 6

    Energy Technology Data Exchange (ETDEWEB)

    1981-06-01

    This volume contains information on the geologic and hydrologic framework, major aquifers, aquifers which are suitable and unsuitable for annual thermal energy storage (ATES) and the ATES potential of the following regions of the US: the Western Mountains; Alluvial Basins; Columbia LAVA Plateau; Colorado Plateau; High Plains; and Glaciated Central Region. (LCL)

  14. 40 CFR 144.7 - Identification of underground sources of drinking water and exempted aquifers.

    Science.gov (United States)

    2010-07-01

    ... of drinking water and exempted aquifers. 144.7 Section 144.7 Protection of Environment ENVIRONMENTAL... Provisions § 144.7 Identification of underground sources of drinking water and exempted aquifers. (a) The..., except where exempted under paragraph (b) of this section, as an underground source of drinking...

  15. 78 FR 19261 - Safe Drinking Water Act Sole Source Aquifer Program; Designation of Bainbridge Island, Washington...

    Science.gov (United States)

    2013-03-29

    ... AGENCY Safe Drinking Water Act Sole Source Aquifer Program; Designation of Bainbridge Island, Washington.... SUMMARY: Notice is hereby given that pursuant to Section 1424(e) of the Safe Drinking Water Act, the... Aquifer System located in Kitsap County, Washington is the sole or principle source of drinking water...

  16. Modelling and monitoring of Aquifer Thermal Energy Storage : impacts of soil heterogeneity, thermal interference and bioremediation

    NARCIS (Netherlands)

    Sommer, W.T.

    2015-01-01

    Modelling and monitoring of Aquifer Thermal Energy Storage Impacts of heterogeneity, thermal interference and bioremediation Wijbrand Sommer
    PhD thesis, Wageningen University, Wageningen, NL (2015)
    ISBN 978-94-6257-294-2 Abstract Aquifer thermal energy storage (ATES) is

  17. Regional assessment of aquifers for thermal-energy storage. Volume 2. Regions 7 through 12

    Energy Technology Data Exchange (ETDEWEB)

    1981-06-01

    This volume contains information on the geologic and hydrologic framework, major aquifers, aquifers which are suitable and unsuitable for annual thermal energy storage (ATES) and the ATES potential of the following regions of the US: Unglaciated Central Region; Glaciated Appalachians, Unglaciated Appalachians; Coastal Plain; Hawaii; and Alaska. (LCL)

  18. Changes in Water Levels and Storage in the High Plains Aquifer, Predevelopment to 2007

    Science.gov (United States)

    McGuire, V.L.

    2009-01-01

    The High Plains aquifer underlies 111.6 million acres (174,000 square miles) in parts of eight States - Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The area overlying the High Plains aquifer is one of the primary agricultural regions in the Nation. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigation with ground water in the aquifer area. By 1980, water levels in the High Plains aquifer in parts of Texas, Oklahoma, and southwestern Kansas had declined more than 100 feet (Luckey and others, 1981). In response to these water-level declines, the U.S. Geological Survey (USGS), in collaboration with numerous Federal, State, and local water-resources agencies, began monitoring more than 7,000 wells in 1988 to assess annual water-level changes in the aquifer. This fact sheet summarizes changes in water levels and drainable water in storage in the High Plains aquifer from predevelopment (before about 1950) to 2007 and serves as a companion product to a USGS report that presents more detailed and technical information about water-level and storage changes in the High Plains aquifer during this period (McGuire,