WorldWideScience

Sample records for coast geopressured aquifers

  1. Geopressured-geothermal aquifers. Final contract report

    Energy Technology Data Exchange (ETDEWEB)

    1983-08-01

    Task 1 is to provide petrophysical and reservoir analysis of wells drilled into geopressured-geothermal aquifers containing dissolved methane. The list of Design Wells and Wells of Opportunity analyzed: Fairfax Foster Sutter No. 2 (WOO), Pleasant Bayou No. 2 (Design), Amoco Fee No. 1 (Design), G.M. Koelemay No. 1 (WOO), Gladys McCall No. 1 (Design), P.R. Girouard No. 1 (WOO), and Crown Zellerbach No. 2 (WOO). Petrophysical and reservoir analysis of the above wells were performed based on availability of data. The analysis performed on each well, the assumptions made during simulation, and conclusions reached.

  2. Environmental overview of geopressured-geothermal development: Texas Gulf Coast

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, T.C.; Kreitler, C.W.

    1979-01-01

    In the summary of the recommended environmental program are: site specific studies, general studies, cost estimates for the program, socioeconomic and demographic research, potential environmental concerns, environmental research, effects of geopressure exploitation, and research plans. The socioeconomic and cultural considerations are impacts on communities. Waste disposal, geologic framework, ground subsidence, and monitoring techniques are discussed. (MHR)

  3. Plan for the long term environmental assessment of geopressured resource development in the Louisiana Gulf Coast Region

    Energy Technology Data Exchange (ETDEWEB)

    Newchurch, E.J.; Bryan, C.F.; Harrison, D.P.; Muller, R.A.; Wilcox, R.E.; Bachman, A.L.; Newman, J.P.; Cunningham, K.J.; Hilding, R.K.; Rehage, J.A.

    1978-07-15

    Results of research to develop a plan for the long-term environmental assessment of geopressured/geothermal resource development in the Louisiana Gulf Coast region are reported. An overall view of the environmental issues facing decision-makers in the area of geopressured resource development is presented, along with a plan for monitoring potential environmental impacts. Separate assessments and plans are presented for geological effects, air and water quality, ecosystem quality, and socioeconomic and cultural considerations. (JGB)

  4. Geopressured aquifers - utilization of the energy potential of the Endorf thermal water deposit

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, S; Hantelmann, G v

    1984-01-01

    The Endorf thermal water deposit (Rupel, 4229 to 4264 m) belongs to the type of ''geopressured aquifers''. The overall aim of the project is to exploit the energy stored in the deposit in the form of thermal brine (temperature: 115/sup 0/C) and natural gas (96% methane). In this first report on the project state, an overview on prehistory is followed by a description of the currently implemented test programme and its subsequent evaluation which aim at obtaining more exact knowledge concerning the present deposit conditions and, while doing so, indications of the energy content of the deposit in order to determine the energy potential theoretically exploitable at the well head.

  5. Analysis of three geopressured geothermal aquifer-natural gas fields; Duson Hollywood and Church Point, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, L.A.; Boardman, C.R.

    1981-05-01

    The available well logs, production records and geological structure maps were analyzed for the Hollywood, Duson, and Church Point, Louisiana oil and gas field to determine the areal extent of the sealed geopressured blocks and to identify which aquifer sands within the blocks are connected to commercial production of hydrocarbons. The analysis showed that over the depth intervals of the geopressured zones shown on the logs essentially all of the sands of any substantial thickness had gas production from them somewhere or other in the fault block. It is therefore expected that the sands which are fully brine saturated in many of the wells are the water drive portion of the producing gas/oil somewhere else within the fault block. In this study only one deep sand was identified, in the Hollywood field, which was not connected to a producing horizon somewhere else in the field. Estimates of the reservoir parameters were made and a hypothetical production calculation showed the probable production to be less than 10,000 b/d. The required gas price to profitably produce this gas is well above the current market price.

  6. Environmental Assessment: Geothermal Energy Geopressure Subprogram. Gulf Coast Well Testing Activity, Frio Formation, Texas and Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-02-01

    This Environmental Assessment (EA) has been prepared to provide the environmental input into the Division of Geothermal Energy's decisions to expand the geothermal well testing activities to include sites in the Frio Formation of Texas and Louisiana. It is proposed that drilling rigs be leased before they are removed from sites in the formation where drilling for gas or oil exploration has been unsuccessful and that the rigs be used to complete the drilling into the geopressured zone for resource exploration. This EA addresses, on a regional basis, the expected activities, affected environment, and the possible impacts in a broad sense as they apply to the Gulf Coast well testing activity of the Geothermal Energy Geopressure Subprogram of the Department of Energy. Along the Texas and Louisiana Gulf Coast (Plate 1 and Overlay, Atlas) water at high temperatures and high pressures is trapped within Gulf basin sediments. The water is confined within or below essentially impermeable shale sequences and carries most or all of the overburden pressure. Such zones are referred to as geopressured strata. These fluids and sediments are heated to abnormally high temperatures (up to 260 C) and may provide potential reservoirs for economical production of geothermal energy. The obvious need in resource development is to assess the resource. Ongoing studies to define large-sand-volume reservoirs will ultimately define optimum sites for drilling special large diameter wells to perform large volume flow production tests. in the interim, existing well tests need to be made to help define and assess the resource.

  7. Investigation and evaluation of geopressured-geothermal wells. Notes on Gruy Federal's Well-of-Opportunity program

    Energy Technology Data Exchange (ETDEWEB)

    1979-02-01

    Obtaining test data from geopressured aquifers along the Texas and Louisiana Gulf Coast by arranging to assume operation of wells already drilled and found nonproductive of conventional oil or gas accumulations before such wells were abandoned by the operators is described. The geopressured aquifers were tested after performing whatever additional operations were required. The monitoring and screening of all wells which might qualify is described. The major activities and important milestones are summarized. (MHR)

  8. Continuity and productivity analysis of three geopressured geothermal aquifer-natural gas fields: Duson, Hollywood and Church Point, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, L.A.; Boardman, C.R.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    The available well logs, production records and geological structure maps were analyzed for the Hollywood, Duson, and Church Point, Louisiana oil and gas fields to determine the areal extent of the sealed geopressured blocks and to identify which aquifer sands within the blocks are connected to commercial production of hydrocarbons. Studies such as these are needed for the Department of Energy program to identify geopressured brine reservoirs that are not connected to commercial productions. The analysis showed that over the depth intervals at the geopressured zones shown on the logs essentially all of the sands of any substantial thickness had gas production from them somewhere or other in the fault block. It is therefore expected that the sands which are fully brine saturated in many of the wells are the water drive portion of the producing gas/oil somewhere else within the fault block. In this study only one deep sand was identified, in the Hollywood field, which was apparently not connected to a producing horizon somewhere else in the field. Estimates of the reservoir parameters were made for this sand and a hypothetical production calculation showed the probable production to be less than 10,000 b/d. The required gas price to profitably produce this gas is well above the current market price.

  9. Gulf Coast geopressured-geothermal program summary report compilation. Volume 4: Bibliography (annotated only for all major reports)

    Energy Technology Data Exchange (ETDEWEB)

    John, C.J.; Maciasz, G.; Harder, B.J.

    1998-06-01

    This bibliography contains US Department of Energy sponsored Geopressured-Geothermal reports published after 1984. Reports published prior to 1984 are documented in the Geopressured Geothermal bibliography Volumes 1, 2, and 3 that the Center for Energy Studies at the University of Texas at Austin compiled in May 1985. It represents reports, papers and articles covering topics from the scientific and technical aspects of geopressured geothermal reservoirs to the social, environmental, and legal considerations of exploiting those reservoirs for their energy resources.

  10. Environmental Assessment: Geothermal Energy Geopressure Subprogram. Gulf Coast Well Drilling and Testing Activity (Frio, Wilcox, and Tuscaloosa Formations, Texas and Louisiana)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-09-01

    The Department of Energy (DOE) has initiated a program to evaluate the feasibility of developing the geothermal-geopressured energy resources of the Louisiana-Texas Gulf Coast. As part of this effort, DOE is contracting for the drilling of design wells to define the nature and extent of the geopressure resource. At each of several sites, one deep well (4000-6400 m) will be drilled and flow tested. One or more shallow wells will also be drilled to dispose of geopressured brines. Each site will require about 2 ha (5 acres) of land. Construction and initial flow testing will take approximately one year. If initial flow testing is successful, a continuous one-year duration flow test will take place at a rate of up to 6400 m{sup 3} (40,000 bbl) per day. Extensive tests will be conducted on the physical and chemical composition of the fluids, on their temperature and flow rate, on fluid disposal techniques, and on the reliability and performance of equipment. Each project will require a maximum of three years to complete drilling, testing, and site restoration.

  11. Environmental impact assessment Geopressure Subprogram

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-07-01

    This environmental impact assessment (EIA) addresses the expected programmatic activities of the Geopressure Subprogram of the Division of Geothermal Energy. The goal of the Geopressure Subprogram is to stimulate development of geopressured resources as an economic, reliable, operationally safe, and environmentally acceptable energy source. The subprogram includes activities in the areas of engineering research and development; resource exploration, assessment, and development; resource utilization including pilot and demonstration facilities; and environmental research and control technology development. It should be recognized that most of the subprogram activities extend over several years and are in their early stages of implementation at this time. The zones of potential geopressure development are in the region located along the Texas and Louisiana Gulf Coasts extending up to 200 miles (300 km) inland. Geopressured zones are sedimentary basins where water is trapped at high pressures within or below thick, nearly impermeable shale sequences. The confined water supports most or all of the weight of the overburden. This inhibits sediment compaction and causes formation pore pressure to exceed hydrostatic pressure. in sedimentary basins that are underlain by thin oceanic crust, upward thermal conduction from the mantle heats geopressured fluids and sediments to abnormally high temperatures, often in excess of 260 C (500 F).

  12. Gulf Coast geopressured-geothermal program summary report compilation. Volume 2-A: Resource description, program history, wells tested, university and company based research, site restoration

    Energy Technology Data Exchange (ETDEWEB)

    John, C.J.; Maciasz, G.; Harder, B.J.

    1998-06-01

    The US Department of Energy established a geopressured-geothermal energy program in the mid 1970`s as one response to America`s need to develop alternate energy resources in view of the increasing dependence on imported fossil fuel energy. This program continued for 17 years and approximately two hundred million dollars were expended for various types of research and well testing to thoroughly investigate this alternative energy source. This volume describes the following studies: Geopressured-geothermal resource description; Resource origin and sediment type; Gulf Coast resource extent; Resource estimates; Project history; Authorizing legislation; Program objectives; Perceived constraints; Program activities and structure; Well testing; Program management; Program cost summary; Funding history; Resource characterization; Wells of opportunity; Edna Delcambre No. 1 well; Edna Delcambre well recompletion; Fairfax Foster Sutter No. 2 well; Beulah Simon No. 2 well; P.E. Girouard No. 1 well; Prairie Canal No. 1 well; Crown Zellerbach No. 2 well; Alice C. Plantation No. 2 well; Tenneco Fee N No. 1 well; Pauline Kraft No. 1 well; Saldana well No. 2; G.M. Koelemay well No. 1; Willis Hulin No. 1 well; Investigations of other wells of opportunity; Clovis A. Kennedy No. 1 well; Watkins-Miller No. 1 well; Lucien J. Richard et al No. 1 well; and the C and K-Frank A. Godchaux, III, well No. 1.

  13. Fingerprinting groundwater salinity sources in the Gulf Coast Aquifer System, USA

    Science.gov (United States)

    Chowdhury, Ali H.; Scanlon, Bridget R.; Reedy, Robert C.; Young, Steve

    2018-02-01

    Understanding groundwater salinity sources in the Gulf Coast Aquifer System (GCAS) is a critical issue due to depletion of fresh groundwater and concerns for potential seawater intrusion. The study objective was to assess sources of groundwater salinity in the GCAS using ˜1,400 chemical analyses and ˜90 isotopic analyses along nine well transects in the Texas Gulf Coast, USA. Salinity increases from northeast (median total dissolved solids (TDS) 340 mg/L) to southwest (median TDS 1,160 mg/L), which inversely correlates with the precipitation distribution pattern (1,370- 600 mm/yr, respectively). Molar Cl/Br ratios (median 540-600), depleted δ2H and δ18O (-24.7‰, -4.5‰) relative to seawater (Cl/Br ˜655 and δ2H, δ18O 0‰, 0‰, respectively), and elevated 36Cl/Cl ratios (˜100), suggest precipitation enriched with marine aerosols as the dominant salinity source. Mass balance estimates suggest that marine aerosols could adequately explain salt loading over the large expanse of the GCAS. Evapotranspiration enrichment to the southwest is supported by elevated chloride concentrations in soil profiles and higher δ18O. Secondary salinity sources include dissolution of salt domes or upwelling brines from geopressured zones along growth faults, mainly near the coast in the northeast. The regional extent and large quantities of brackish water have the potential to support moderate-sized desalination plants in this location. These results have important implications for groundwater management, suggesting a current lack of regional seawater intrusion and a suitable source of relatively low TDS water for desalination.

  14. The geopressured-geothermal resource

    International Nuclear Information System (INIS)

    Wys, J.N.; Dorfman, M.

    1990-01-01

    This paper reports that the Geopressured-Geothermal resource has an estimated 5,700 recoverable quad of gas and 11,000 recoverable quad of thermal energy in the onshore Texas and Louisiana Gulf Coasts area alone. After 15 years the program is now beginning a transition to commercialization. The program presently has three geopressured-geothermal wells in Texas and Louisiana. The Pleasant Bayou Well has a 1 MWe hybrid power system converting some gas and the thermal energy to electricity. The Gladys McCall Well produced over 23 MM bbls brine with 23 scf per bbl over 4 1/2 years. It is now shut-in building up pressure. The deep Hulin Well has been cleaned out and short term flow tested. It is on standby awaiting funds for long-term flow testing. In January 1990 an Industrial Consortium for the Utilization of the Geopressured-Geothermal Resource was convened at Rice University, Houston, TX. Sixty-five participants heard industry cost-shared proposals for using the hot geopressured brine. Proposals ranged from thermal enhanced oil recovery to aquaculture, conversion, and environmental clean up processes. By the September meeting at UTA-Balcones Research Center, industry approved charters will have been received, an Advisory Board will be appointed, and election of officers from industry will he held

  15. Characterization of California Central Coast Aquifers using Pneumatic Slug Tests

    Science.gov (United States)

    Aurelius, S.; Platt, D.; Whetsler, B.; Malama, B.

    2017-12-01

    The recent prolonged drought in California, where about 75% of the population depends to some extent ongroundwater, has led to increased stresses on the state's groundwater resources due to reduced recharge andincreased abstraction to supplement dwindling surface water supplies for irrigation and other urban uses.These factors have conspired to cause historic lows in groundwater levels, lost aquifer storage capacity dueincreased potential for land subsidence, and degraded water quality in coastal aquifers faced with increasedrates of seawater intrusion. Groundwater accounts for about a third of the total water uses in California,with some coastal communities being 100% dependent on groundwater. Irrigation accounts for over 60%of all state groundwater withdrawals in California. In light of this, the state of California recently passedthe Sustainable Groundwater Management Act (SGMA) aimed at bringing the State's groundwater basinsinto sustainable regimes of abstraction, recharge and storage. Groundwater ow models are critical to thesuccessful implementation of the SGMA legislation. However, the usefulness of the models is severely limitedby a lack of detailed knowledge of aquifer properties at spatial scales that allow for accurate projections tobe made about groundwater basin sustainability by resource managers. We report here the results of highresolution pneumatic slug tests performed in two shallow aquifers in San Luis Obispo County on the CaliforniaCentral Coast to obtain detailed information about aquifer properties, including permeability and storage,and their spatial variability.

  16. Environmental impact of geopressure - geothermal cogeneration facility on wetland resources and socioeconomic characteristics in Louisiana Gulf Coast region. Final report, October 10, 1983-September 31, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Smalley, A.M.; Saleh, F.M.S.; Fontenot, M.

    1984-08-01

    Baseline data relevant to air quality are presented. The following are also included: geology and resource assessment, design well prospects in southwestern Louisiana, water quality monitoring, chemical analysis subsidence, microseismicity, geopressure-geothermal subsidence modeling, models of compaction and subsidence, sampling handling and preparation, brine chemistry, wetland resources, socioeconomic characteristics, impacts on wetlands, salinity, toxic metals, non-metal toxicants, temperature, subsidence, and socioeconomic impacts. (MHR)

  17. Gulf Coast geopressured-geothermal program summary report compilation. Volume 2-B: Resource description, program history, wells tested, university and company based research, site restoration

    Energy Technology Data Exchange (ETDEWEB)

    John, C.J.; Maciasz, G.; Harder, B.J.

    1998-06-01

    The US Department of Energy established a geopressured-geothermal energy program in the mid 1970`s as one response to America`s need to develop alternate energy resources in view of the increasing dependence on imported fossil fuel energy. This program continued for 17 years and approximately two hundred million dollars were expended for various types of research and well testing to thoroughly investigate this alternative energy source. This volume describes the following studies: Design well program; LaFourche Crossing; MG-T/DOE Amoco Fee No. 1 (Sweet Lake); Environmental monitoring at Sweet Lake; Air quality; Water quality; Microseismic monitoring; Subsidence; Dow/DOE L.R. Sweezy No. 1 well; Reservoir testing; Environmental monitoring at Parcperdue; Air monitoring; Water runoff; Groundwater; Microseismic events; Subsidence; Environmental consideration at site; Gladys McCall No. 1 well; Test results of Gladys McCall; Hydrocarbons in production gas and brine; Environmental monitoring at the Gladys McCall site; Pleasant Bayou No. 2 well; Pleasant Bayou hybrid power system; Environmental monitoring at Pleasant Bayou; and Plug abandonment and well site restoration of three geopressured-geothermal test sites. 197 figs., 64 tabs.

  18. Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.

    1982-06-01

    A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

  19. Energy Resources of Water-Bearing Geopressured Reservoirs-Tertiary Formations, Northwestern Gulf of Mexico (Summary Ressources énergétiques des réservoirs aquifères à pressions géostratégiques dans les formations tertiaires du golfe du Mexique (résumé

    Directory of Open Access Journals (Sweden)

    Bebout D. G.

    2006-11-01

    Full Text Available Estimates for the total gas resource in place in geopressured Tertiary sandstone reservoirs along the United States Gulf Coast range from 3,000 to 100,000 tcf 185 to 2,832 trillion cu m. This wide range in estimates was the incentive for initiative research effort in Texas and Louisiane to obtain more reliable data on all aspects of developing the available heat and hydraulic energy present in these aquifers in addition to the methane. All resource calculations are based on interpretations of total sandstone thickness, lateral extent of reservoirs, porosity and permeability, reservoir drive, salinity, temperature, pressure, and methane solubility. Diverse estimates arise from inadequate knowledge concerning these critical parameters. Regional and detailed local geologic studies have been conducted ta delineate prospective areas for testing the geopressured resource. A prospective area should have reservoir volume of 3 Cu mi (12 cu km, minimum permeability of 20 mD, and fluid temperatures of 300°F (150°C. A geothermal designed test well has been drilled in Brazoria County, Texas, in order to test the potential of producing up to 40,000 barrels of water per day from a geopressured reservoir. The reservoir consists of 250 to 300 ft (75 to 90 m of sandstone with core permeabilities between 40 and 60 mD and fluid temperatures from 300 to 350°F (159 to 177°C. The test period will continue for a 2-year period and, with other designed tests in Texas and Louisiana will provide invaluable data concerning high-volume production over long periods of time. Les estimations pour les ressources totales de gaz dans les réservoirs sableux tertiaires à pressions géostatiques le long de la Gulf Coast des Etats-Unis sont corises entre 3000 et 100 000 tcf, soit 85 à 2832. 10. 12 m3. Cette large incertitude a incité la mise en oeuvre d'un effort extensif de recherche au Texas et en Louisiane en vue d'obtenir des données plus sûres sur tous les aspects du d

  20. Environmental assessment of the projected uses for geopressured waters

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.S.; Manning, J.A.; Meriwether, J.

    1977-11-16

    An assessment of possible environmental effects of the use of geopressured water of the Texas and Louisiana Gulf Coast has been made. The uses considered include generation of electric power, production of low pressure steam for process heat and the direct use of the hot water for space heating. Based upon the projected uses, the direct and indirect emissions are estimated and the impact of these emissions upon the environment are discussed. The possible impacts of the production of large volumes of geopressured fluids are also considered in terms of possibility of subsidence and earthquakes. A summary of available analyses of Gulf Coast deep waters is listed as a guide for estimating expected emissions. Primary environmental problems are identified as waste brine disposal, accidental releases of brines, and subsidence. Minor problems such as cooling tower blowdown streams, noncondensable gas emissions, wind drift from exhaust plumes, noise levels, and construction activities are considered.

  1. Geothermal energy geopressure subprogram

    Energy Technology Data Exchange (ETDEWEB)

    1981-02-01

    The proposed action will consist of drilling one geopressured-geothermal resource fluid well for intermittent production testing over the first year of the test. During the next two years, long-term testing of 40,000 BPD will be flowed. A number of scenarios may be implemented, but it is felt that the total fluid production will approximate 50 million barrels. The test well will be drilled with a 22 cm (8.75 in.) borehole to a total depth of approximately 5185 m (17,000 ft). Up to four disposal wells will provide disposal of the fluid from the designated 40,000 BPD test rate. The following are included in this assessment: the existing environment; probable environmental impacts-direct and indirect; probable cumulative and long-term environmental impacts; accidents; coordination with federal, state, regional, and local agencies; and alternative actions. (MHR)

  2. Parcperdue Geopressure -- Geothermal Project: Appendix E

    Energy Technology Data Exchange (ETDEWEB)

    Sweezy, L.R.

    1981-10-05

    The mechanical and transport properties and characteristics of rock samples obtained from DOW-DOE L.R. SWEEZY NO. 1 TEST WELL at the Parcperdue Geopressure/Geothermal Site have been investigated in the laboratory. Elastic moduli, compressibility, uniaxial compaction coefficient, strength, creep parameters, permeability, acoustic velocities (all at reservoir conditions) and changes in these quantities induced by simulated reservoir production have been obtained from tests on several sandstone and shale samples from different depths. Most important results are that the compaction coefficients are approximately an order of magnitude lower than those generally accepted for the reservoir sand in the Gulf Coast area and that the creep behavior is significant. Geologic characterization includes lithological description, SEM micrographs and mercury intrusion tests to obtain pore distributions. Petrographic analysis shows that approximately half of the total sand interval has excellent reservoir potential and that most of the effective porosity in the Cib Jeff Sand is formed by secondary porosity development.

  3. Hydrologic conditions in the South Coast aquifer, Puerto Rico, 2010–15

    Science.gov (United States)

    Torres-Gonzalez, Sigfredo; Rodriguez, Jose M.

    2016-01-15

    In 1958, the U.S. Geological Survey began documenting hydrologic conditions, including groundwater levels, groundwater withdrawals for agricultural irrigation and public water supply, and water quality, in the South Coast aquifer, Puerto Rico. This information has improved the understanding of the water resources of the region. The hydrologic data indicate that (1) groundwater levels declined as much as 40 feet in the Salinas area and 11 feet in the Guayama area during 2012–14; (2) groundwater withdrawals for agricultural irrigation increased from 6.0 to 10.5 million gallons per day, or 75 percent, from 2010 to 2012; and (3) total groundwater withdrawals decreased from 29.3 to 23.8 million gallons per day from 2010 to 2014. The quantity and quality of water in the aquifer is primarily affected by variations in aquifer recharge as a result of changing rainfall or modes of irrigation; however, the spatial patterns and magnitude of water withdrawals for all uses have a secondary impact on the quantity and quality of water in the aquifer.

  4. Problem definition study of subsidence caused by geopressured geothermal resource development

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The environmental and socio-economic settings of four environmentally representative Gulf Coast geopressured geothermal fairways were inventoried. Subsidence predictions were prepared using feasible development scenarios for the four representative subsidence sites. Based on the results of the subsidence estimates, an assessment of the associated potential environmental and socioeconomic impacts was prepared. An inventory of mitigation measures was also compiled. Results of the subsidence estimates and impact assessments are presented, as well as conclusions as to what are the major uncertainties, problems, and issues concerning the future study of geopressured geothermal subsidence.

  5. Investigation and Evaluation of Geopressured - Geothermal Wells, Final Report; Alice C. Plantation No. 2 Well, St. Mary Parish, Louisiana; Volume 1; Narrative Report

    Energy Technology Data Exchange (ETDEWEB)

    Lohse, Alan; Willits, M.H.

    1978-12-01

    Gruy Federal, Inc. (Gruy) operates under Contract No. EG-77-C-08-1528 to the Department of Energy, Division of Geothermal Energy, to evaluate potential alternate energy sources occurring within geopressured-geothermal (Geo) aquifers in Miocene, Oligocene, Tuscaloosa, Wilcox, and Frio formations along the Texas and Louisiana Gulf Coast. The project is entitled ''Investigation and Evaluation of Geopressured-Geothermal Wells''. The original period of performance was from September 26, 1977, through September 30, 1978; the contract was later extended through September 30, 1979. The first well on which testing was attempted under this contract was the Alice C. Plantation No. 2 Well, located in St. Mary Parish, Louisiana. Originally drilled by the Sun Oil Company to a total depth of 19,000 feet, this well was abandoned as a dry hole in January 1964. Gruy's reentry attempt ended with plugging and abandonment after a saltwater flow on September 17, 1978. This report is a comprehensive document detailing all events and costs relating to the Alice C. plantation well, from its initial selection as a reentry well through the plugging and abandonment operations.

  6. Groundwater quality of the Gulf Coast aquifer system, Houston, Texas, 2010

    Science.gov (United States)

    Oden, Jeannette H.; Brown, Dexter W.; Oden, Timothy D.

    2011-01-01

    During March–December 2010, the U.S. Geological Survey, in cooperation with the city of Houston, collected source-water samples from 60 municipal supply wells in the Houston area. These data were collected as part of an ongoing study to determine concentrations, spatial extent, and associated geochemical conditions that might be conducive for mobility and transport of selected naturally occurring contaminants (selected trace elements and radionuclides) in the Gulf Coast aquifer system in the Houston area. In the summers of 2007 and 2008, a reconnaissance-level survey of these constituents in untreated water from 28 municipal supply wells was completed in the Houston area. Included in this report are the complete analytical results for 47 of the 60 samples collected in 2010—those results which were received from the laboratories and reviewed by the authors as of December 31, 2010. All of the wells sampled were screened in the Gulf Coast aquifer system; 22 were screened entirely in the Evangeline aquifer, and the remaining 25 wells contained screened intervals that intersected both Evangeline and Chicot aquifers. The data documented in this report were collected as part of an ongoing study to characterize source-water-quality conditions in untreated groundwater prior to drinking-water treatment. An evaluation of contaminant occurrence in source water provides background information regarding the presence of a contaminant in the environment. Because source-water samples were collected prior to any treatment or blending that potentially could alter contaminant concentrations, the water-quality results documented by this report represent the quality of the source water, not the quality of finished drinking water provided to the public.

  7. Geopressured energy availability. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-01

    Near- and long-term prospects that geopressured/geothermal energy sources could become a viable alternative fuel for electric power generation were investigated. Technical questions of producibility and power generation were included, as well as economic and environmental considerations. The investigators relied heavily on the existing body of information, particularly in geotechnical areas. Statistical methods were used where possible to establish probable production values. Potentially productive geopressured sediments have been identified in twenty specific on-shore fairways in Louisiana and Texas. A total of 232 trillion cubic feet (TCF) of dissolved methane and 367 x 10/sup 15/ Btu (367 quads) of thermal energy may be contained in the water within the sandstone in these formations. Reasonable predictions of the significant reservoir parameters indicate that a maximum of 7.6 TCF methane and 12.6 quads of thermal energy may be producible from these potential reservoirs.

  8. 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).

  9. 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).

  10. Proceedings of second geopressured geothermal energy conference, Austin, Texas, February 23--25, 1976. Volume V. Legal, institutional, and environmental

    Energy Technology Data Exchange (ETDEWEB)

    Vanston, J.H.; Elmer, D.B.; Gustavson, T.C.; Kreitler, C.W.; Letlow, K.; Lopreato, S.C.; Meriwether, M.; Ramsey, P.; Rogers, K.E.; Williamson, J.K.

    1976-01-01

    Three separate abstracts were prepared for Volume V of the Proceedings of the Conference. Sections are entitled: Legal Issues in the Development of Geopressured--Geothermal Resources of Texas and Louisiana Gulf Coast; The Development of Geothermal Energy in the Gulf Coast; Socio-economic, Demographic, and Political Considerations; and Geothermal Resources of the Texas Gulf Coast--Environmental Concerns arising from the Production and Disposal of Geothermal waters. (MCW)

  11. Groundwater quality in the shallow aquifers of the Monterey Bay, Salinas Valley, and adjacent highland areas, Southern Coast Ranges, California

    Science.gov (United States)

    Burton, Carmen

    2018-05-30

    The Monterey-Salinas Shallow Aquifer study unit covers approximately 7,820 square kilometers (km2) in Santa Cruz, Monterey, and San Luis Obispo Counties in the Central Coast Hydrologic Region of California. The study unit was divided into four study areas—Santa Cruz, Pajaro Valley, Salinas Valley, and Highlands. More than 75 percent of the water used for drinking-water supply in the Central Coast Hydrologic Region of California is groundwater, and there are more than 8,000 well driller’s logs for domestic wells (California Department of Water Resources, 2013).

  12. Reliable Predictors of Arsenic Occurrence in the Southern Gulf Coast Aquifer of Texas

    Directory of Open Access Journals (Sweden)

    Kartik Venkataraman

    2018-04-01

    Full Text Available Arsenic contamination of groundwater in the Southern Gulf Coast Aquifer of Texas is a critical public health concern as much of the area is rural in nature with decentralized water supplies. Previous studies have pointed to volcanic deposits as the regional source of arsenic but no definitive or reliable predictors of arsenic maximum contaminant level (MCL exceedance have been identified. In this study, we have studied the effect of various hydrogeochemical parameters as well as soil and land-use variables on arsenic MCL exceedance using logistic regression (LR techniques. The LR models display good accuracy of 75% or higher but suffer from a high rate of false negatives, highlighting the challenges in capturing the spatial irregularities of arsenic in this region. Despite not displaying high statistical significance, pH appears to be an important variable in the LR models—its effect on arsenic exceedance is not clear and warrants further investigation. The results of the study also show that groundwater vanadium and fluoride are consistently the only significant variables in the models developed; the positive coefficients for both these elements indicates a common geogenic source for arsenic, fluoride and vanadium, corroborating the findings of earlier studies.

  13. Geopressured-geothermal well activities in Louisiana

    International Nuclear Information System (INIS)

    John, C.J.

    1992-10-01

    Since September 1978, microseismic networks have operated continuously around US Department of Energy (DOE) geopressured-geothermal well sites to monitor any microearthquake activity in the well vicinity. Microseismic monitoring is necessary before flow testing at a well site to establish the level of local background seismicity. Once flow testing has begun, well development may affect ground elevations and/or may activate growth faults, which are characteristic of the coastal region of southern Louisiana and southeastern Texas where these geopressured-geothermal wells are located. The microseismic networks are designed to detest small-scale local earthquakes indicative of such fault activation. Even after flow testing has ceased, monitoring continues to assess any microearthquake activity delayed by the time dependence of stress migration within the earth. Current monitoring shows no microseismicity in the geopressured-geothermal prospect areas before, during, or after flow testing

  14. Geopressured geothermal bibliography. Volume 1 (citation extracts)

    Energy Technology Data Exchange (ETDEWEB)

    Hill, T.R.; Sepehrnoori, K.

    1981-08-01

    This bibliography was compiled by the Center for Energy Studies at The University of Texas at Austin to serve as a tool for researchers in the field of geopressured geothermal energy resources. The bibliography represents citations of papers on geopressured geothermal energy resources over the past eighteen years. Topics covered in the bibliography range from the technical aspects of geopressured geothermal reservoirs to social, environmental, and legal aspects of tapping those reservoirs for their energy resources. The bibliography currently contains more than 750 entries. For quick reference to a given topic, the citations are indexed into five divisions: author, category, conference title, descriptor, and sponsor. These indexes are arranged alphabetically and cross-referenced by page number.

  15. 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....

  16. Groundwater-Quality Survey of the South Coast Aquifer of Puerto Rico, April 2 through May 30, 2007

    Science.gov (United States)

    Rodriguez, Jose M.; Gómez-Gómez, Fernando

    2009-01-01

    The increased potential for variability of groundwater quality in the South Coast aquifer of Puerto Rico due to saline water encroachment from the Caribbean Sea and from deep parts of the aquifer has become a major concern of water planners and managers. In an effort to determine the extent and sources of this encroachment, the U.S. Geological Survey (USGS) and the Puerto Rico Department of Natural and Environmental Resources conducted a synoptic groundwater-quality survey from April 2 through May 30, 2007, for the South Coast aquifer between Ponce and Arroyo (fig. 1). Groundwater resources in this aquifer extend 150 square miles in south-central Puerto Rico and provide an estimated 44.2 million gallons per day (Mgal/d) or about 61 percent of the total water needs. This amount includes: 15.3 Mgal/d for irrigation, 27.4 Mgal/d for public supply, and 1.5 Mgal/d for industrial and other uses (W.L. Molina-Rivera, U.S. Geological Survey, written commun., 2007). Since 1980 when most of the south coastal plain was intensively cultivated for sugarcane, total groundwater withdrawals have declined about 32 Mgal/d with the greatest decline occurring in irrigation (37.2 Mgal/d) and the greatest increase occurring in public supply (5.5 Mgal/d). Although withdrawals have declined substantially, a major concern is that aquifer recharge provided by irrigation return flow from surface-water irrigation canals has essentially dropped to zero because of the large-scale implementation of groundwater drip irrigation systems.

  17. Groundwater quality of the Gulf Coast aquifer system, Houston, Texas, 2007-08

    Science.gov (United States)

    Oden, Jeannette H.; Oden, Timothy D.; Szabo, Zoltan

    2010-01-01

    In the summers of 2007 and 2008, the U.S. Geological Survey (USGS), in cooperation with the City of Houston, Texas, completed an initial reconnaissance-level survey of naturally occurring contaminants (arsenic, other selected trace elements, and radionuclides) in water from municipal supply wells in the Houston area. The purpose of this reconnaissance-level survey was to characterize source-water quality prior to drinking water treatment. Water-quality samples were collected from 28 municipal supply wells in the Houston area completed in the Evangeline aquifer, Chicot aquifer, or both. This initial survey is part of ongoing research to determine concentrations, spatial extent, and associated geochemical conditions that might be conducive for mobility and transport of these constituents in the Gulf Coast aquifer system in the Houston area. Samples were analyzed for major ions (calcium, magnesium, potassium, sodium, bromide, chloride, fluoride, silica, and sulfate), selected chemically related properties (residue on evaporation [dissolved solids] and chemical oxygen demand), dissolved organic carbon, arsenic species (arsenate [As(V)], arsenite [As(III)], dimethylarsinate [DMA], and monomethylarsonate [MMA]), other trace elements (aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, copper, iron, lead, lithium, manganese, molybdenum, nickel, selenium, silver, strontium, thallium, vanadium, and zinc), and selected radionuclides (gross alpha- and beta-particle activity [at 72 hours and 30 days], carbon-14, radium isotopes [radium-226 and radium-228], radon-222, tritium, and uranium). Field measurements were made of selected physicochemical (relating to both physical and chemical) properties (oxidation-reduction potential, turbidity, dissolved oxygen concentration, pH, specific conductance, water temperature, and alkalinity) and unfiltered sulfides. Dissolved organic carbon and chemical oxygen demand are presented but not discussed in the

  18. Geopressured-geothermal drilling and testing plan. General Crude Oil--Dept. of Energy Pleasant Bayou No. 1 well, Brazoria County, Texas

    Energy Technology Data Exchange (ETDEWEB)

    1978-05-01

    As a result of geopressured resource assessment studies in the Gulf Coast region, the Brazoria fairway, located in Brazoria County, Texas was determined to be an optimum area for additional studies. A plan is presented for drilling, completion, and testing of one geopressured-geothermal well and two disposal wells in Brazoria County, Texas. The objectives of the well drilling and testing program are to determine the following parameters: reservoir permeability, porosity, thickness, rock material properties, depth, temperature, and pressure; reservoir fluid content, specific gravity, resistivity, viscosity, and hydrocarbons in solution; reservoir fluid production rates, pressure, temperature, production decline, and pressure decline; geopressured well and surface equipment design requirements for high-volume production and possible sand production; specific equipment design for surface operations, hydrocarbons distribution, and effluent disposal; and possibilities of reservoir compaction and/or surface subsidence. (JGB)

  19. Aquifer Characterization from Surface Geo-electrical Method, western coast of Maharashtra, India

    Science.gov (United States)

    DAS, A.; Maiti, D. S.

    2017-12-01

    Knowledge of aquifer parameters are necessary for managing groundwater amenity. These parameters are evaluated through pumping tests bring off from bore wells. But it is quite expensive as well as time consuming to carry out pumping tests at various sites and sometimes it is difficult to find bore hole at every required site. Therefore, an alternate method is put forward in which the aquifer parameters are evaluated from surface geophysical method. In this method, vertical electrical sounding (VES) with Schlumberger configuration were accomplished in 85 stations over Sindhudurg district. Sindhudurg district is located in the Konkan region of Maharashtra state, India. The district is located between north latitude 15°37' and 16° 40' and east longitude 73° 19' and 74° 13'. The area is having hard rock and acute groundwater problem. In this configuration, we have taken the maximum current electrode spacing of 200 m for every vertical electrical sounding (VES). Geo-electrical sounding data (true resistivity and thickness) is interpreted through resistivity inversion approach. The required parameters are achieved through resistivity inversion technique from which the aquifer variables (D-Z parameters, mean resistivity, hydraulic conductivity, transmissivity, and coefficient of anisotropy) are calculated by using some empirical formulae. Cross-correlation investigation has been done between these parameters, which eventually used to characterize the aquifer over the study area. At the end, the contour plot for these aquifer parameters has been raised which reveals the detailed distribution of aquifer parameters throughout the study area. From contour plot, high values of longitudinal conductance, hydraulic conductivity and transmissivity are demarcate over Kelus, Vengurle, Mochemar and Shiroda villages. This may be due to intrusion of saline water from Arabian sea. From contour trends, the aquifers are characterized from which the groundwater resources could be

  20. Geothermal resources: Frio Formation, Middle Texas Gulf Coast. Geological circular 75-8

    Energy Technology Data Exchange (ETDEWEB)

    Bebout, D.G.; Agagu, O.K.; Dorfman, M.H.

    1975-01-01

    Regional sand distribution of the Frio Formation is determined; depositional environments are identified; and the geopressured zone and its relationship to sand/shale distribution, growth faults, and fluid temperatures in the Middle Texas Gulf Coast are delineated. (MHR)

  1. Geopressured-geothermal energy development: government incentives and institutional structures

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, D.O.; Prestwood, D.C.L.; Roberts, K.; Vanston, J.H. Jr.

    1979-01-01

    The following subjects are included: a geothermal resource overview, the evolution of the current Texas geopressured-geothermal institutional structure, project evaluation with uncertainty and the structure of incentives, the natural gas industry, the electric utility industry, potential governmental participants in resource development, industrial users of thermal energy, current government incentives bearing on geopressured-geothermal development, six profiles for utilization of the geopressured-geothermal resources in the mid-term, and probable impacts of new government incentives on mid-term resource utilization profiles. (MHR)

  2. Mapping of coastal aquifer vulnerable zone in the south west coast of Kanyakumari, South India, using GIS-based DRASTIC model.

    Science.gov (United States)

    Kaliraj, S; Chandrasekar, N; Peter, T Simon; Selvakumar, S; Magesh, N S

    2015-01-01

    The south west coast of Kanyakumari district in Tamil Nadu, India, is significantly affected by seawater intrusion and diffusion of pollutants into the aquifers due to unregulated beach placer mining and other anthropogenic activities. The present study investigates the vulnerability of the coastal aquifers using Geographic Information System (GIS)-based DRASTIC model. The seven DRASTIC parameters have been analyzed using the statistical equation of this model to demarcate the vulnerable zones for aquifer contamination. The vulnerability index map is prepared from the weighted spatial parameters, and an accounting of total index value ranged from 85 to 213. Based on the categorization of vulnerability classes, the high vulnerable zones are found near the beach placer mining areas between Manavalakurichi and Kodimanal coastal stretches. The aquifers associated with settlements and agricultural lands in the middle-eastern part have experienced high vulnerability due to contaminated water bodies. Similarly, the coastal areas of Thengapattinam and Manakudi estuary and around the South Tamaraikulam have also been falling under high vulnerability condition due to backwater and saltpan. In general, the nearshore region except the placer mining zone and the backwater has a moderately vulnerable condition, and the vulnerability index values range from 149 to180. Significantly, the northern and northeastern uplands and some parts of deposition zones in the middle-south coast have been identified as low to no vulnerable conditions. They are structurally controlled by various geological features such as charnockite, garnet biotite gneiss and granites, and sand dunes, respectively. The aquifer vulnerability assessment has been cross-verified by geochemical indicators such as total dissolved solids (TDS), Cl(-), HCO₃(-), and Cl(-)/HCO₃(-) ratio. The high ranges of TDS (1,842--3,736 mg/l) and Cl(-) (1,412--2,112 mg/l) values are well correlated with the observed high

  3. Arsenic and radionuclide occurrence and relation to geochemistry in groundwater of the Gulf Coast Aquifer System in Houston, Texas, 2007–11

    Science.gov (United States)

    Oden, Jeannette H.; Szabo, Zoltan

    2016-03-21

    The U.S. Geological Survey (USGS), in cooperation with the City of Houston, began a study in 2007 to determine concentrations, spatial extent, and associated geochemical conditions that might be conducive for mobility and transport of selected naturally occurring trace elements and radionuclides in the Gulf Coast aquifer system in Houston, Texas. Water samples were collected from 91 municipal supply wells completed in the Evangeline and Chicot aquifers of the Gulf Coast aquifer system in northeastern, northwestern, and southwestern Houston; hereinafter referred to as northeast, northwest and southwest Houston areas. Wells were sampled in three phases: (1) 28 municipal supply wells were sampled during 2007–8, (2) 60 municipal supply wells during 2010, and (3) 3 municipal supply wells during December 2011. During each phase of sampling, samples were analyzed for major ions, selected trace elements, and radionuclides. At a subset of wells, concentrations of arsenic species and other radionuclides (carbon-14, radium-226, radium-228, radon-222, and tritium) also were analyzed. Selected physicochemical properties were measured in the field at the time each sample was collected, and oxidation-reduction potential and unfiltered sulfides also were measured at selected wells. The source-water (the raw, ambient water withdrawn from municipal supply wells prior to water treatment) samples were collected for assessment of aquifer conditions in order to provide community water-system operators information that could be important when they make decisions about which treatment processes to apply before distributing finished drinking water.

  4. Parcperdue Geopressure--Geothermal Project: Appendix B

    Energy Technology Data Exchange (ETDEWEB)

    Sweezy, L.R.

    1981-10-05

    The reservoir models used to perform the drawdown and buildup pressure analyses consist of analytic forms in lieu of the finite difference or numeric simulator types. Analytic models are derived from solutions of the diffusion equation which relate a pressure response with time and distance in the reservoir for a specified flow system. Solutions of the diffusion equation are obtained through mathematical methods such as Laplace transforms, Fourier transforms, Neuman's product techniques and Green's functions. Before an analytic solution is derived, the diffusivity equation is expressed in terms of dimensionless potential (m{sub D}), dimensionless distance (r{sub D}) and dimensionless time (t{sub D}). For the cylindrical coordinate case, the diffusivity equation in dimensionless form for a geopressured system is given.

  5. Depletion and recovery behavior of the Gladys McCall geopressured geothermal reservoir

    International Nuclear Information System (INIS)

    Riney, T.D.

    1991-01-01

    Many sedimentary basins throughout the world contain sealed fault blocks in which the pore fluids are at higher pressures and temperatures than normal as a consequence of their depositional environment. The U.S. Department of Energy has drilled, completed, and tested four deep research wells in selected geopressured geothermal prospects in the Texas-Louisiana Gulf Coast region to evaluate the recoverability of the thermal, hydraulic, and chemical (methane) energy in this potential energy resource. The wells are expensive and the specific energy of the fluids is relatively small, but the total recoverable energy from a single well can be extremely large. Long-term testing of the Gladys McCall No. 1 research well, located in Cameron Parish, Louisiana, U.S.A., has defined an impressively large geopressured geothermal reservoir. In this paper an integrated analysis of the test data is presented, and a numerical model is constructed that matches the available data for the 6.5-year test history of the well

  6. Hydro geochemistry and isotopic approach of coastal aquifer systems of Cap Bon : The case of tablecloths and the eastern coast of El Haourai - Tunisia

    International Nuclear Information System (INIS)

    Ben Hammouda, Fethi

    2008-01-01

    As many other semi-arid regions, the Cap Bon peninsula (N.E. Tunisia) shows a parallel increase in overexploitation and mineralization of groundwater resources. In the eastern coast and El Haouaria aquifers, the groundwater quality is threatened. Surveys including level measurements, water sampling, chemical analysis (ions Na+, Cl., Ca2+, Mg2+, Br.) and sotopes (18O, 2H, 3H, 13C, 14C) were performed in 2001, 2002 and 2003. Several analysis types were conducted and results are compared with the hydrodynamic information for identifying the main processes involved in the mineralization increase. Particularly, the isotopes were permitting the understanding of the hydrogeological of the concerned aquifers and the localization of the recharge zones. Because the regional situation along the seashore, the seawater intrusion in the unconfined Plio-quaternary aquifer, resulting from the groundwater overexploitation, and obvious explanation for the rising salinity is identified but is not the only cause of the qualitative degradation: the irrigation development that induces the soil leaching and the fertilizers transfer to groundwater over the whole aquifer extent is another major reason of the mineralization increase. Piezometric and salinity maps of the Plio-quaternary aquifer were established. The continuous increase in pumping has created several depressions in the water table, up to 12 m below msl and induced a deterioration of the water quality. The temporal changes in water-table level and salinity are often similar which suggests a strong link between them. Several geochemical approaches were performed to identify the importance of the marine intrusion in the increase in mineralization. The salinity of the groundwater appears to originate from dissolution of minerals in the aquifer system

  7. Analysis of ecological effects of geopressured-geothermal resource development. Geopressured-geothermal technical paper No. 4

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    The activities involved in geopressured-geothermal resource production are identified and their ecological impacts are discussed. The analysis separates those activites that are unique to geopressured-geothermal development from those that also occur in oil and gas and other resource developments. Of the unique activities, those with the greatest potential for serious ecological effect are: (1) accidental brine discharge as a result of a blowout during well drilling; (2) subsidence; (3) fault activation and enhanced seismicity; and (4) subsurface contamination of water, hydrocarbon, and mineral reservoirs. Available methods to predict and control these effects are discussed.

  8. Planning report for the Gulf Coast Regional Aquifer-System Analysis in the Gulf of Mexico coastal plain, United States

    Science.gov (United States)

    Grubb, Hayes F.

    1984-01-01

    Large quantities of water for municipal, industrial and agriculture use are supplied from the aquifers in Tertiary and younger sediments over an area of about 225,000 square miles in the Coastal Plain of Alabama, Arkansas, Florida, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas. Three regional aquifer systems, the Mississippi Embayment aquifer system, the Coastal Lowlands aquifer system, and the Texas Coastal Uplands aquifer system have been developed to varying degrees throughout the area. A variety of problems has resulted from development such as movement of the saline-freshwater interface into parts of aquifers that were previously fresh, lowering of the potentiometric surface with resulting increases in pumping lift, and land-surface subsidence due to the compaction of clays within the aquifer. Increased demand for ground water is anticipated to meet the needs of urban growth, expanded energy development, and growth of irrigated agriculture. The U. S. Geological Survey initiated an eightyear study in 1981 to define the geohydrologic framework, describe the chemistry of the ground water, and to analyze the regional ground-water flow patterns. The objectives, plan, and organization of the study are described in this report and the major tasks to be undertaken are outlined.

  9. Origin and generation mechanisms of geopressures in shale ...

    African Journals Online (AJOL)

    Geopressures influences many fluid related aspects of petroleum geology including diagenesis, migration and accumulation of oil and gas ,and indeed reservoir quality. It also constitutes a hazard in drilling wells and directly impacts on drilling costs and the safety of petroleum exploration. The general overview of the ...

  10. Geopressured geothermal bibliography. Volume I. Citation extracts. Second edition

    Energy Technology Data Exchange (ETDEWEB)

    Sepehrnoori, K.; Carter, F.; Schneider, R.; Street, S.; McGill, K.

    1983-05-01

    This annoted bibliography contains 1131 citations. It represents reports, papers, and articles appearing over the past eighteen years covering topics from the scientific and technical aspects of geopressured geothermal reservoirs to the social, environmental, and legal considerations of exploiting those reservoirs for their energy resources. Six indexes include: author, conference title, descriptor, journal title, report number, and sponsor. (MHR)

  11. Industry participation in DOE-sponsored geopressured geothermal resource development. Final report, 1 September 1977-30 April 1979

    Energy Technology Data Exchange (ETDEWEB)

    Coffer, H.F.

    1979-01-01

    A series of DOE/Industry forums were carried out to keep industry advised of the DOE program to develop the geopressured geothermal resources of the Gulf Coast. A total of eighteen meetings were held with registered attendance of 621 representing a good cross section of industry, state, and federal agencies. An Overview Group and four working subgroups - site selection, drilling and testing, environmental/laboratory research, and legal institutional were established to subdivide the DOE programs into areas of interest and expertise. During the contract period three overview, four site selection, three drilling and testing, five environmental/laboratory research and three legal/institutional meetings have been conducted. Interest in and attendance at the meetings continue to grow reflecting increased industry contact with the DOE Geopressured Geothermal Resource Development Program. Two other studies were carried out for DOE under this contract; a Salt Water Disposal Study and an Industry Survey to evaluate the DOE Resource Development Program. The Salt Water Disposal Study reviewed subsurface salt water disposal experience on the Texas and Louisiana Gulf Coast. This preliminary study concluded that subsurface brine disposal should be possible in the areas of interest with adequate evaluation of the geology of each area and a well designed and constructed surface and subsurface facility. The industry survey indicated general satisfaction with the technical design of the resource evaluation program but felt the program should be moving faster.

  12. Geopressured-geothermal test of the EDNA Delcambre No. 1 well, Tigre Lagoon Field, Vermilion Parish, Louisiana: analysis of water an dissolved natural gas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hankins, B.E.; Karkalits, O.C.

    1978-09-01

    The Edna Delcambre et al. No. 1 gas well, shut-in since June 1975, was made available for the project. Two geopressured sand-bed aquifers were tested: sand No. 3 at a depth of 12,900 feet and sand No. 1 at a depth of 12,600 feet. Each aquifer was subjected to flow tests which lasted approximately three weeks in each case. Water samples were obtained during flow testing of the two geopressured aquifers. The water contained 11.3 to 13.3% dissolved solids. Several radioactive species were measured. Radium-226 was found to be approximately 10 times more concentrated than the average amount observed in surface waters. No appreciable amount of heavy metals was detected. Recombination studies at bottom-hole conditions indicate the solubility of natural gas per barrel of water to be about 24 SCF. The methane content was 93 to 95%, and the gas had a heating value in the range of 1020 to 1070 Btu/cu.ft. During the flow tests, the gas/water ratio at the well-head was observed to be 45 to 88 SCF/Bbl water produced. (MHR)

  13. Focus on CSIR research in water resources: Managed aquifer recharge on the west coast north of Cape Town, South Africa

    CSIR Research Space (South Africa)

    Colvin, C

    2007-08-01

    Full Text Available The Atlantis Water Resource Management Scheme (AWRMS) located some 40 km north of Cape Town shows how insightful planning and management can expand the groundwater supply potential of a primary aquifer for bulk urban water supply. The AWRMS...

  14. Geochemical And Hydrodynamic Behavior Of The Karstic Aquifer System In The Portion Between Akumal And Boca Paila, In The South Eastern Coast Of The Yucatan Peninsula.

    Science.gov (United States)

    Velazquez Oliman, G.; Leal Bautista, R. M.; Perry, E. C.; Carrol, M.; Wagner, N.; Castillo Oliman, P.

    2008-12-01

    We report here aspects of the geochemistry and hydrodynamics of a nearly 450 km2 area that constitutes part of the rapidly developing tourist corridor between Akumal and Boca Paila, Quintana Roo, Mexico. Some of the largest explored submerged cave systems in the world, including Nohoch Nah Chic and Dos Ojos, are within the study area. The presence of these and other highly permeable conduits highlights the importance of a better understanding of the aquifer system both to assess its vulnerability and to facilitate sustainable water management. This study focuses on major ion, trace element, and stable isotope geochemistry of groundwater and on monitoring system hydrodynamics through water levels measurements. Sampling along approximately 30 km of coast was accomplished by means of a network of 29 sampling sites arranged along three NW-SE transverse lines running approximately perpendicular to the coast and each extending about 16 km inland. To date 52 samples have been taken. In addition, vertical specific conductivity profiles have helped delineate the thickness of the freshwater lens, which has a maximum thickness of 33.5 m in the southwestern part of the study area, approximately 13.5 km from the coast. In the northeastern corner of the study area, 7.5 m of brackish water overlies sea water near the coast. Water level monitoring is by means of Schlumberger pressure transducers installed at 11 sites. Water table changes record tidal oscillation, confirming the interconnectedness of the system, an observation supported by conductivity measurements that indicate oscillatory vertical movement of the saline interface. (SO4/Cl) ratios, expressed as 1000(SO4/Cl) in meq/kg, are useful tracers of groundwater provenance. The ratio is approximately 100 for seawater and is much greater for groundwater in southern Quintana Roo that has dissolved evaporite (Perry et al, 2002). Ratios in the study area, which are 100 or less, indicate no contact with evaporite. Background

  15. A study on variation in dissolved silica concentration in groundwater of hard rock aquifers in Southeast coast of India

    International Nuclear Information System (INIS)

    Pradeep, K; Nepolian, M; Anandhan, P; Chandran; Kaviyarasan, R; Chidambaram, S; Prasanna, M V

    2016-01-01

    Ground water of hard rock aquifers due to its lesser permeability results in the increased residence time, which leads to the higher concentration of ions. Hence in order to understand the hydro-geochemistry of the groundwater of a hard rock aquifer in India, 23 groundwater samples were collected from different locations of the study area and subjected to analysis of major cations and anions. The results of silica showed different range of concentration and was plotted in different groups. In order to understand the reason for this variation, different techniques like Thermodynamics, Statistics and GIS were adopted and it was inferred that the concentration was mainly governed by lithology and land use pattern of the study area. (paper)

  16. Environmental analysis of geopressured-geothermal prospect areas, Brazoria and Kenedy Counties, Texas

    Energy Technology Data Exchange (ETDEWEB)

    White, W.A.; McGraw, M.; Gustavson, T.C.

    1978-01-01

    Preliminary environmental data, including current land use, substrate lithology, soils, natural hazards, water resources, biological assemblages, meteorological data, and regulatory considerations have been collected and analyzed for approximately 150 km/sup 2/ of land: (1) near Chocolate Bayou, Brazoria County, Texas, where a geopressured-geothermal test well was drilled in 1978, and (2) near the rural community of Armstrong, Kenedy County, Texas, where future geopressured-geothermal test well development may occur. The study was designed to establish an environmental data base and to determine, within spatial constraints set by subsurface reservoir conditions, environmentally suitable sites for geopressured-geothermal wells.

  17. Legal impediments to the development of the geopressured resource

    Energy Technology Data Exchange (ETDEWEB)

    Harrell, T.A.; Meriwether, J.

    1977-11-16

    A brief description is given of the physical characteristics of geopressured reservoirs and the methods of their exploitation upon which this analysis was based. Brief mention is made of some technological problems facing the developer. A summary description of the ownership of the resource in Louisiana and of the devices available for its development are set forth. The legal problems which result from the interplay of these factors are discussed, and a brief suggestion is made as to the kinds of action which might be taken to resolve these problems and expedite development. (MHR)

  18. Consolidation of geologic studies of geopressured geothermal resources in Texas. 1982 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Morton, R.A.; Ewing, T.E.; Kaiser, W.R.; Finley, R.J.

    1983-03-01

    Detailed structural mapping at several horizons in selected study areas within the Frio growth-fault trend demonstrates a pronounced variability in structural style. At Sarita in South Texas, shale mobilization produced one or more shale ridges, one of which localized a low-angle growth fault trapping a wedge of deltaic sediments. At Corpus Christi, shale mobilization produced a series of large growth faults, shale-cored domed anticlines, and shale-withdrawal basins, which become progressively younger basinward. At Blessing, major growth faults trapped sands of the Greta/Carancahua barrier system with little progradation. At Pleasant Bayou, a major early growth-fault pattern was overprinted by later salt tectonics - the intrusion of Danbury Dome and the development of a salt-withdrawal basin. At Port Arthur, low-displacement, long-lived faults formed on a sand-poor shelf margin contemporaneously with broad salt uplifts and basins. Variability in styles is related to the nature and extent of Frio sedimentation and shelf-margin progradation and to the presence or absence of salt. Structural styles that are conducive to the development of large geothermal reservoirs include blocks between widely spaced growth faults having dip reversal, salt-withdrawal basins, and shale-withdrawal basins. These styles are widespread on the Texas Gulf Coast. However, actually finding a large reservoir depends on demonstrating the existence of sufficient sandstone with adequate quality to support geopressured geothermal energy production.

  19. Utilizing potential field data to support delineation of groundwater aquifers in the southern Red Sea coast, Saudi Arabia

    International Nuclear Information System (INIS)

    Elawadi, Eslam; Mogren, Saad; Ibrahim, Elkhedr; Batayneh, Awni; Al-Bassam, Abdulaziz

    2012-01-01

    In this paper potential field data are interpreted to map the undulation of the basement surface, which represents the bottom of the water bearing zones, and to delineate the tectonic framework that controls the groundwater flow and accumulation in the southern Red Sea coastal area of Saudi Arabia. The interpretation reveals that the dominant structural trend is a NW (Red Sea) trend that resulted in a series of faulted tilted blocks. These tilted blocks are dissected by another cross-cut NE trend which shapes and forms a series of fault-bounded small basins. These basins and the bounded structural trends control and shape the flow direction of the groundwater in the study area, i.e. they act as groundwater conduits. Furthermore, the present results indicate that volcanic intrusions are present as subsurface flows, which hinder the groundwater exploration and drilling activities in most of the area; in some localities these volcanic flows crop out at the surface and cover the groundwater bearing formations. Furthermore, the gravity and magnetic data interpretation indicates the possible existence of a large structural basin occupying the southeastern side of the study area. This basin is bounded with NW and NE trending faults and is expected to be a good host for groundwater aquifers; thus it is a promising site for hydrogeological investigation. (paper)

  20. Technical support for geopressured-geothermal well activities in Louisiana

    International Nuclear Information System (INIS)

    John, C.J.

    1994-01-01

    The US Department of Energy has operated continuous-recording, microearthquake monitoring networks at geopressured-geothermal test well sites since 1980. These microseismic networks were designed to detect microearthquakes indicative of fault activation and/or subsidence that can potentially result from the deep subsurface withdrawal and underground disposal of large volumes of brine during well testing. Seismic networks were established before the beginning of testing to obtain background levels of seismicity. Monitoring continued during testing and for some time after cessation of flow testing to assess any delayed microseismicity caused by the time dependence of stress migration within the earth. No flow testing has been done at the Hulin well since January 1990, and the Pleasant Bayou well has been shut down since September 1992. Microseismic monitoring continued at the Hulin and Pleasant Bayou sites until 31 December 1992, at which time both operations were shut down and field sites dismantled. During 1992, the networks recorded seismic signals from earthquakes, sonic booms, geophysical blasting, thunderstorms, etc. However, as in previous years, no local microseismic activity attributable to geopressured-geothermal well testing was recorded

  1. Investigation and evaluation of geopressured-geothermal wells. Fairfax Foster Sutter No. 2 well, St. Mary Parish, Louisiana. Volume I. Completion and testing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Willits, M.H.; McCoy, R.L.; Dobson, R.J.; Hartsock, J.H.

    1979-12-01

    The Fairfax Foster Sutter No. 2 well, located in the East Franklin area of St. Mary Parish, Louisiana, is the first successful test of a geopressured-geothermal aquifer under the Well-of-Opportunity program. The section tested was the MA-6 sand of lower Miocene age which has produced large quantities of gas from the adjacent but structurally separated Garden City field. In the subject well the observed temperature was 270{sup 0}F (132{sup 0}C) and the measured gradient was 0.77 psi/ft. The gross sand thickness was 270 feet, the net sand thickness 190 feet, and the tested interval 58 net feet. The temperatures and pressures encountered approached the limits of the surface-recording bottomhole pressure gauge and particularly the single-conductor cables on which the gauges were run. The objectives of the tests were all accomplished, and data were obtained which will contribute to the overall assessment of the geopressured-geothermal resource of the Upper Gulf of Mexico basin. In general, the gas solubility (22.8 scf/bbl) was as expected for the temperature, pressure, and salinity of the brine. The produced water was more saline than expected (160,000 mg/l). The high concentrations of dissolved solids, coupled with the evolution of CO{sub 2} from these waters during production, created a scaling problem in the tubular goods and surface equipment that will have to be addressed in future tests.

  2. Fluid sampling and chemical modeling of geopressured brines containing methane. Final report, March 1980-February 1981

    Energy Technology Data Exchange (ETDEWEB)

    Dudak, B.; Galbraith, R.; Hansen, L.; Sverjensky, D.; Weres, O.

    1982-07-01

    The development of a flowthrough sampler capable of obtaining fluid samples from geopressured wells at temperatures up to 400/sup 0/F and pressures up to 20,000 psi is described. The sampler has been designed, fabricated from MP35N alloy, laboratory tested, and used to obtain fluid samples from a geothermal well at The Geysers, California. However, it has not yet been used in a geopressured well. The design features, test results, and operation of this device are described. Alternative sampler designs are also discussed. Another activity was to review the chemistry and geochemistry of geopressured brines and reservoirs, and to evaluate the utility of available computer codes for modeling the chemistry of geopressured brines. The thermodynamic data bases for such codes are usually the limiting factor in their application to geopressured systems, but it was concluded that existing codes can be updated with reasonable effort and can usefully explain and predict the chemical characteristics of geopressured systems, given suitable input data.

  3. Assessing aquifer vulnerability from lumped parameter modeling of modern water proportions in groundwater mixtures - Application to nitrate pollution in California's South Coast Range

    Science.gov (United States)

    Hagedorn, B.; Ruane, M.; Clark, N.

    2017-12-01

    In California, the overuse of synthetic fertilizers and manure in agriculture have caused nitrate (NO3) to be one of the state's most widespread groundwater pollutants. Given that nitrogen fertilizer applications have steadily increased since the 1950s and given that soil percolation and recharge transit times in California can exceed timescales of decades, the nitrate impact on groundwater resources is likely a legacy for years and even decades to come. This study presents a methodology for groundwater vulnerability assessment that operates independently of difficult-to-constrain soil and aquifer property data (i.e., saturated thickness, texture, porosity, conductivity, etc.), but rather utilizes groundwater age and, more importantly, groundwater mixing information to illustrate actual vulnerability at the water table. To accomplish this, the modern (i.e., less than 60-year old) water proportion (MWP) in groundwater mixtures is computed via lumped parameter modeling of chemical tracer (i.e., 3H, 14C and 3Hetrit) data. These MWPs are then linked to groundwater dissolved oxygen (DO) values to describe the risk for soil zone-derived nitrate to accumulate in the saturated zone. Preliminary studies carried out for 71 wells in California's South Coast Range-Coastal (SCRC) study unit reveal MWP values derived from binary dispersion models of 3.24% to 21.8%. The fact that high MWPs generally coincide with oxic (DO ≥1.5 mg/L) groundwater conditions underscores the risk towards increased groundwater NO3 pollution for many of the tested wells. These results support the conclusion that best agricultural management and policy objectives should incorporate groundwater vulnerability models that are developed at the same spatial scale as the decision making.

  4. Geopressured-geothermal resource development on public free school lands

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    The study's findings and recommendations are based upon analysis of the following: financial and economic feasibility of geopressured-geothermal resource development; possible ecological, social, and economic impacts of resource development on PFSL; and legal issues associated with resource development. The results of the analysis are summarized and are discussed in detail in a series of four technical papers which accompany this volume. Existing rules of the General Land Office (GLO), the School Land Board (SLB), and the Railroad Commission of Texas (RRC) were reviewed in light of the above analysis and were discussed with the agencies. The study's recommendations resulted from this analytical and review process; they are discussed. The preliminary draft rules and regulations to govern resource development on PFSL are presented in Appendix A; the accompanying forms and model lease are found in Appendix B.

  5. T-F and S/DOE Gladys McCall No. 1 well, Cameron Parish, Louisiana. Geopressured-geothermal well report, Volume II. Well workover and production testing, February 1982-October 1985. Final report. Part 1

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The T-F and S/DOE Gladys McCall No. 1 well was the fourth in a series of wells in the DOE Design Wells Program that were drilled into deep, large geopressured-geothermal brine aquifers in order to provide basic data with which to determine the technological and economic viability of producing energy from these unconventional resources. This brine production well was spudded on May 27, 1981 and drilling operations were completed on November 2, 1981 after using 160 days of rig time. The well was drilled to a total depth of 16,510 feet. The target sands lie at a depth of 14,412 to 15,860 feet in the Fleming Formation of the lower Miocene. This report covers well production testing operations and necessary well workover operations during the February 1982 to October 1985 period. The primary goals of the well testing program were: (1) to determine reservoir size, shape, volume, drive mechanisms, and other reservoir parameters, (2) to determine and demonstrate the technological and economic viability of producing energy from a geopressured-geothermal brine aquifer through long-term production testing, and (3) to determine problem areas associated with such long-term production, and to develop solutions therefor.

  6. The feasibility of applying geopressured-geothermal resources to direct uses

    Science.gov (United States)

    Lunis, Ben C.; Dewys, Jane Negus; Plum, Martin M.; Lienau, Paul J.; Spencer, F. J.; Nitschke, George F.

    1991-09-01

    This study concludes that direct use technologies, especially desalinated water production, can contribute significantly to the value added process and the overall economic viability in developing a geopressured resource. Although agriculture and aquaculture applications are marginal projects when they are the only use of a geopressured well, the small margin of profitability can contribute to improving the overall economics of the direct use development. The added complexity from a technical and management aspect may add to the overall risk and unpredictability of the project. Six combinations of direct uses received economic evaluation that resulted in 15 percent discounted payback periods ranging from 4 to over 10 years. Many other combinations are possible depending on the resource and market variables. Selection of appropriate technologies and sizes of applications will be established by the developer that engages in geopressured resource utilization. Currently, many areas of the country where geopressured resources are located also have surplus electrical capacity and generation; thus power utilities have been selling power for less than two cents per kWH, well below a reasonable breakeven value for geopressured produced electricity. However, when the energy demand of the integrated geopressured facility is large enough to install power generation equipment, operating expenses can be reduced by not paying the 10 to 12 cents per kWH utility rate. The study includes an analysis of a geothermal turbine unit installed with a desalination and an agriculture/aquaculture facility, taking advantage of the cascading energy values. Results suggest that this scenario becomes profitable only where the market price for electricity exceeds five cents per kWH.

  7. The feasibility of applying geopressured-geothermal resources to direct uses

    Energy Technology Data Exchange (ETDEWEB)

    Lunis, B.C.; Negus-de Wys, J.; Plum, M.M. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Lienau, P.J. (Oregon Inst. of Tech., Klamath Falls, OR (United States). Geo-Heat Center); Spencer, F.J. (International Management Services (United States)); Nitschke, G.F. (Nitschke (George F.) (United States))

    1991-09-01

    This study concludes that direct use technologies, especially desalinated water production, can contribute significantly to the value added process and the overall economic viability in developing a geopressured resource. Although agriculture and aquaculture applications are marginal projects when they are the only use of a geopressured well, the small margin of profitability can contribute to improving the overall economics of the direct use development. The added complexity from a technical and management aspect may add to the overall risk and unpredictability of the project. Six combination of direct uses received economic evaluation that resulted in 15% discounted payback periods ranging from 4 to over 10 years. Many other combinations are possible depending on the resource and market variables. Selection of appropriate technologies and sizes of applications will be established by the developer that engages in geopressured resource utilization. Currently, many areas of the country where geopressured resources are located also have surplus electrical capacity and generation, thus power utilities have been selling power for less than 2 cents per kWH, well below a reasonable breakeven value for geopressured produced electricity. However, when the energy demand of the integrated geopressured facility is large enough to install power generation equipment, operating expenses can be reduced by not paying the 10 to 12 cents per kWH utility rate. The study includes an analysis of a geothermal turbine unit installed with a desalination and an agriculture/aquaculture facility, taking advantage of the cascading energy values. Results suggest that this scenario becomes profitable only where the market price for electricity exceeds five cents per kWH.

  8. Parcperdue geopressure-geothermal project. Study a geopressured reservoir by drilling and producing a well in a limited geopressured water sand. Final technical report, September 28, 1979-December 31, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, J.R.; Stanley, J.G. (eds.)

    1984-01-15

    The behavior of geopressured reservoirs was investigated by drilling and producing a well in small, well defined, geopressured reservoir; and performing detailed pressure transient analysis together with geological, geophysical, chemical, and physical studies. The Dow-DOE L. R. Sweezy No. 1 well was drilled to a depth of 13,600 feet in Parcperdue field, just south of Lafayette, Louisiana, and began production in April, 1982. The production zone was a poorly consolidated sandstone which constantly produced sand into the well stream, causing damage to equipment and causing other problems. The amount of sand production was kept manageable by limiting the flow rate to below 10,000 barrels per day. Reservoir properties of size, thickness, depth, temperature, pressure, salinity, porosity, and permeability were close to predicted values. The reservoir brine was undersaturated with respect to gas, containing approximately 20 standard cubic feet of gas per barrel of brine. Shale dewatering either did not occur or was insignificant as a drive mechanism. Production terminated when the gravel-pack completion failed and the production well totally sanded in, February, 1983. Total production up to the sanding incident was 1.94 million barrels brine and 31.5 million standard cubic feet gas.

  9. Geothermal Energy Geopressure Subprogram, GCO-DOE, Pleasant Bayou No. 1

    Energy Technology Data Exchange (ETDEWEB)

    none

    1978-03-01

    This Environmental Assessment (EA) has been prepared to assess the environmental implications of the Department of Energy's proposal to drill, complete, and test one geopressure well located in Brazoria County on a 2 hectares (five acre) test site 64 km (40 mi) south of Houston, Abstract 107, Perry and Austin Survey, Brazoria County, TX. The test well is herein referred to as GCO-DOE Pleasant Bayou No. 1. A maximum of four disposal wells will be located within .8 km (1/2 mi) of the proposed well. The DOE and the University of Texas Center for Energy Studies propose to operate the test facility for three years to evaluate the geopressure potential of the subsurface. Tests to be conducted include flow rates, fluid composition, temperature, gas content, geologic characteristics, and the land subsidence potential for subsequent production.

  10. 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...

  11. Assessment of the geothermal/geopressure potential of the Gulf Coastal Plan of Alabama. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.V.; Wang, G.C.; Mancini, E.A.; Benson, D.J.

    1980-01-01

    Geothermal and geopressure as well as geologic and geophysical data were studied to evaluate the potential for future development of geothermal resources underlying the Alabama Coastal Plain. Wire-line log data compiled and interpreted from more than 1300 oil and gas test wells included maximum recorded temperatures, mud weights, rock resistivities as related to geopressure, formation tops, fault locations, and depths to basement rock. The Alabama Coastal Plain area is underlain by a conduction dominated, deep sedimentary basin where geothermal gradients are low to moderate (1.0 to 1.8/sup 0/F/100 feet). In some areas of southwest Alabama, abnormally high temperatures are found in association with geopressured zones within the Haynesville Formation of Jurassic age; however, rocks of poor reservoir quality dominate this formation, with the exception of a 200-square-mile area centered in southernmost Clarke County where a porous and permeable sand unit is encased within massive salt deposits of the lower Haynesville. The results of a petrograhic study of the Smackover Formation, which underlies the Haynesville, indicate that this carbonate rock unit has sufficient porosity in some areas to be considered a potential geothermal reservoir. Future development of geothermal resources in south Alabama will be restricted to low or moderate temperature, non-electric applications, which constitute a significant potential energy source for applications in space heating and cooling and certain agricultural and industrial processes.

  12. Industrial Consortium for the Utilization of the Geopressured-Geothermal Resource. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Negus-deWys, J. (ed.)

    1990-03-01

    The Geopressured-Geothermal Program, now in its fifteenth year, is entering the transition period to commercial use. The industry cost-shared proposals to the consortium, represented in the presentations included in these proceedings, attest to the interest developing in the industrial community in utilizing the geopressured-geothermal resource. Sixty-five participants attended these sessions, two-thirds of whom represented industry. The areas represented by cost-shared proposals include (1) thermal enhanced oil recovery, (2) direct process use of thermal energy, e.g., aquaculture and agriculture, (3) conversion of thermal energy to electricity, (4) environment related technologies, e.g., use of supercritical processes, and (5) operational proposals, e.g., a field manual for scale inhibitors. It is hoped that from this array of potential use projects, some will persist and be successful in proving the viability of using the geopressured-geothermal resource. Such industrial use of an alternative and relatively clean energy resource will benefit our nation and its people.

  13. 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.

  14. Legal problems inherent in the development of geopressured and geothermal resources in Louisiana. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harrell, T.A.; Pike, R.W.; Wilkins, B.; Hill, T.M.

    1978-03-01

    The legal framework within which the geopressured resource will have to be developed in Louisiana is discussed generally. Those problems which may be created by its development within that framework are identified. Where possible, solutions are offered to those problems or at least techniques or devices are indicated which might be considered in their resolution. Finally, a compendium is assembled of those statutory or regulatory provisions which may regulate or affect the resource to the end that it might serve as a handbook for the evaluation of the legal and institutional problems which will face a prospective developer, when and if the resource development is undertaken in Louisiana. (MHR)

  15. Microseismic monitoring of Chocolate Bayou, Texas: The Pleasant Bayou no. 2 geopressured/geothermal energy test well program

    Science.gov (United States)

    Mauk, F. J.; Kimball, B.; Davis, R. A.

    The Brazoria seismic network, instrumentation, design, and specifications are described. The data analysis procedures are presented. Seismicity is described in relation to the Pleasant Bayou production history. Seismicity originating near the chemical plant east of the geopressured/geothermal well is discussed.

  16. Contractor for geopressured-geothermal sites: Final contract report, Volume 1, fiscal years 1986--1990 (5 years), testing of wells through October 1990

    Energy Technology Data Exchange (ETDEWEB)

    1992-09-01

    Field tests and studies were conducted to determine the production behavior of geopressured-geothermal reservoirs and their potential as future energy sources. Results are presented for Gladys McCall Site, Pleasant Bayou Site, and Hulin Site.

  17. 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...

  18. Preliminary environmental analysis of a geopressured-geothermal test well in Brazoria County, Texas

    Energy Technology Data Exchange (ETDEWEB)

    White, W.A.; McGraw, M.; Gustavson, T.C.; Meriwether, J.

    1977-11-16

    Preliminary environmental data, including current land use, substrate lithology, soils, natural hazards, water resources, biological assemblages, meteorological data, and regulatory considerations have been collected and analyzed for approximately 150 km/sup 2/ of land near Chocolate Bayou, Brazoria County, Texas, in which a geopressured-geothermal test well is to be drilled in the fall of 1977. The study was designed to establish an environmental data base and to determine, within spatial constraints set by subsurface reservoir conditions, environmentally suitable sites for the proposed well. Preliminary analyses of data revealed the eed for focusing on the following areas: potential for subsidence and fault activation, susceptibility of test well and support facilities to fresh- and salt-water flooding, possible effects of produced saline waters on biological assemblages and groundwaer resources, distribution of expansive soils, and effect of drilling and associated support activities on known archeological-cultural resources.

  19. Guarani aquifer

    International Nuclear Information System (INIS)

    2007-01-01

    The environmental protection and sustain ability develop project of Guarani Aquifer System is a join work from Argentina, Brazil, Paraguay and Uruguay with a purpose to increase the knowledge resource and propose technical legal and organizational framework for sustainable management between countries.The Universities funds were created as regional universities support in promotion, training and academic research activities related to environmental al social aspects of the Guarani Aquifer System.The aim of the project is the management and protection of the underground waters resources taking advantage and assesment for nowadays and future generations

  20. Environmental analysis of geopressured-geothermal prospect areas, De Witt and Colorado counties, Texas. Final report, March 1 - August 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, T.C.; Reeder, F.S.; Badger, E.A.

    1980-02-01

    Information collected and analyzed for a preliminary environmental analysis of geopressured geothermal prospect areas in Colorado and DeWitt Counties, Texas is presented. Specific environmental concerns for each geopressured geothermal prospect area are identified and discussed. Approximately 218 km/sup 2/(85 mi/sup 2/) were studied in the vicinity of each prospect area to: (1) conduct an environmental analysis to identify more and less suited areas for geopressured test wells; and (2) provide an environmental data base for future development of geopressured geothermal energy resources. A series of maps and tables are included to illustrate environmental characteristics including: geology, water resources, soils, current land use, vegetation, wildlife, and meteorological characteristics, and additional relevant information on cultural resources, power- and pipelines, and regulatory agencies. A series of transparent overlays at the scale of the original mapping has also been produced for the purposes of identifying and ranking areas of potential conflict between geopressured geothermal development and environmental characteristics. The methodology for ranking suitability of areas within the two prospect areas is discussed in the appendix. (MHR)

  1. Preliminary environmental assessment of selected geopressured - geothermal prospect areas: Louisiana Gulf Coast Region. Volume II. Environmental baseline data

    Energy Technology Data Exchange (ETDEWEB)

    Newchurch, E.J.; Bachman, A.L.; Bryan, C.F.; Harrison, D.P.; Muller, R.A.; Newman, J.P. Jr.; Smith, C.G. Jr.; Bailey, J.I. Jr.; Kelly, G.G.; Reibert, K.C.

    1978-10-15

    A separate section is presented for each of the six prospect areas studied. Each section includes a compilation and discussion of environmental baseline data derived from existing sources. The data are arranged as follows: geology and geohydrology, air quality, water resources and flood hazards, ecological systems, and land use. When data specific to the prospect were not available, regional data are reported. (MHR)

  2. Evaluation of NEPA-based environmental commitments at four geopressure design wells

    Energy Technology Data Exchange (ETDEWEB)

    Reed, A.W.; Hunsaker, D.B. Jr.; Roop, R.D.; Webb, J.W.

    1983-09-01

    The implementation of environmental mitigation and monitoring commitments made for four geopressure design well projects was evaluated. The evaluation was based on site visits conducted in August 1982 and April 1983 and on a review of monitoring and project activity reports provided by DOE contractors. The projects evaluated include: Pleasant Bayou No. 1 in Brazoria County, Texas; Dow Parcperdue in Vermilion Parish, Louisiana; and Gladys McCall and Sweet Lake No. 1 well sites in Cameron Parish, Louisiana. The contractors responsible for drilling and testing activities at the well sites have adequately implemented most of the mitigation measures described in each project's site-specific Environmental Assessment (EA). Exceptions include the lack of impermeable liners for drilling mud pits at the Dow Parcperdue, Gladys McCall, and Pleasant Bayou sites and the lack of a ring levee at the Pleasant Bayou site. Air and water quality and noise monitoring activities were not performed as strictly as outlined in the EAs. A review of the monitoring data collected to date indicates that no significant environmental degradation has occurred. This report recommends additional or future monitoring needs, especially with regard to soil contamination, subsidence, and microseismicity, and provides guidance for decommissioning.

  3. Methods for collection and analysis of geopressured geothermal and oil field waters

    Energy Technology Data Exchange (ETDEWEB)

    Lico, M.S.; Kharaka, Y.K.; Carothers, W.W.; Wright, V.A.

    1982-01-01

    Present methods are described for the collection, preservation, and chemical analysis of waters produced from geopressured geothermal and petroleum wells. Detailed procedures for collection include precautions and equipment necessary to ensure that the sample is representative of the water produced. Procedures for sample preservation include filtration, acidification, dilution for silica, methyl isobutyl ketone (MIBK) extraction of aluminum, addition of potassium permanganate to preserve mercury, and precipitation of carbonate species as strontium carbonate for stable carbon isotopes and total dissolved carbonate analysis. Characteristics determined at the well site are sulfide, pH, ammonia, and conductivity. Laboratory procedures are given for the analysis of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, iron, manganese, zinc, lead, aluminum, and mercury by atomic absorption and flame emission spectroscopy. Chloride is determined by silver nitrate titration and fluoride by ion-specific electrode. Bromide and iodide concentrations are determined by the hypochlorite oxidation method. Sulfate is analyzed by titration using barium chloride with thorin indicator after pretreatment with alumina. Boron and silica are determined colorimetrically by the carmine and molybdate-blue methods, respectively. Aliphatic acid anions (C/sub 2/ through C/sub 5/) are determined by gas chromatography after separation and concentration in a chloroform-butanol mixture.

  4. Methods for collection and analysis of geopressured geothermal and oil field waters

    Science.gov (United States)

    Lico, Michael S.; Kharaka, Yousif K.; Carothers, William W.; Wright, Victoria A.

    1982-01-01

    Present methods are described for the collection, preservation, and chemical analysis of waters produced from geopressured geothermal and petroleum wells. Detailed procedures for collection include precautions and equipment necessary to ensure that the sample is representative of the water produced. Procedures for sample preservation include filtration, acidification, dilution for silica, methyl isobutyl ketone (MIBK) extraction of aluminum, addition of potassium permanganate to preserve mercury, and precipitation of carbonate species as strontium carbonate for stable carbon isotopes and total dissolved carbonate analysis. Characteristics determined at the well site are sulfide, pH, ammonia, and conductivity. Laboratory procedures are given for the analysis of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, iron, manganese, zinc, lead, aluminum, .and mercury by atomic absorption and flame emission spectroscopy. Chloride is determined by silver nitrate titration and fluoride by ion-specific electrode. Bromide and iodide concentrations are determined by the hypochlorite oxidation method. Sulfate is analyzed by titration using barium chloride with thorin indicator after pretreatment with alumina. Boron and silica are determined colorimetrically by the carmine and molybdate-blue methods, respectively. Aliphatic acid anions (C2 through C5) are determined by gas chromatography after separation and concentration in a chloroform-butanol mixture.

  5. Gulf Coast Programmatic Environmental Assessment Geothermal Well Testing: The Frio Formation of Texas and Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-10-01

    In accordance with the requirements of 10 CFR Part 711, environmental assessments are being prepared for significant activities and individual projects of the Division of Geothermal Energy (DGE) of the Energy Research and Development Administration (ERDA). This environmental assessment of geopressure well testing addresses, on a regional basis, the expected activities, affected environments, and possible impacts in a broad sense. The specific part of the program addressed by this environmental assessment is geothermal well testing by the take-over of one or more unsuccessful oil wells before the drilling rig is removed and completion of drilling into the geopressured zone. Along the Texas and Louisiana Gulf Coast (Plate 1 and Overlay) water at high temperatures and high pressures is trapped within Gulf basin sediments. The water is confined within or below essentially impermeable shale sequences and carries most or all of the overburden pressure. Such zones are referred to as geopressured strata. These fluids and sediments are heated to abnormally high temperatures (up to 260 C) and may provide potential reservoirs for economical production of geothermal energy. The obvious need in resource development is to assess the resource. Ongoing studies to define large-sand-volume reservoirs will ultimately define optimum sites for drilling special large diameter wells to perform large volume flow production tests. In the interim, existing well tests need to be made to help define and assess the resource. The project addressed by this environmental assessment is the performance of a geothermal well test in high potential geothermal areas. Well tests involve four major actions each of which may or may not be required for each of the well tests. The four major actions are: site preparation, drilling a salt-water disposal well, actual flow testing, and abandonment of the well.

  6. Using presence of calcite cap rock in shales to predict occurrence of reservoirs composed of leached secondary porosity in the geopressured zone. Annual report, June 1, 1980-October 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, W.R.; Magara, K.; Milliken, K.L.; Richmann, D.L.

    1981-01-01

    The distribution of high-resistivity shale in the Frio Formation between hydropressured and geopressured strata has been mapped along the Texas Gulf Coast. Two high-resistivity intervals more than 1000 ft thick have been mapped, one in Brazoria and Galveston Counties and the other in Kenedy County. They coincide with Frio delta systems and may be related to extraordinary quantities of CO/sub 2/ produced by deltaic sediments rich in woody and herbaceous matter. Beyond being calcareous, the nature of the high-resistivity interval is enigmatic and its relationship to deep secondary porosity problematic. Most of the contained carbonate is microscopically and isotopically skeletal in origin, revealing no evidence of diagenetic modification. Minor rhombs of iron-bearing carbonate tens of microns in size were identified. Detrital feldspar compositions are being established to test subsequent changes in feldspar composition resulting from progressive burial and albitization. Hydrolysis reactions for authigenic minerals and reactions between key pairs of minerals have been written. Thermodynamic functions for complex phyllosilicates at temperatures up to 200/sup 0/C have been calculated. From thermodynamic calculations it was predicted that ferroan calcite would be the favored authigenic carbonate in shales.

  7. Inventory and case studies of Louisiana, non-electric industrial applications of geopressured geothermal resources. Quarterly progress report, March 1-May 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Schnadelbach, T.W. Jr.

    1977-06-01

    An inventory is provided of geopressured geothermal resources in Louisiana. The Louisiana industries; classified as Food and Kindred Products were cataloged and inventoried to determine potential and specific uses of the known energy resources. The possibility of relocating industries to the available resources is explored. Individual case studies are presented for near term industrial conversion for resource application. (MHR)

  8. Coast Guard

    International Nuclear Information System (INIS)

    1991-09-01

    The 11-million gallon Exxon Valdez oil spill highlighted deficiencies in the nation's ability to contain and recover spilled oil. The Oil Pollution Act of 1990 represents a major effort by Congress to address these deficiencies and to clarify the roles and responsibilities of the private sector and the federal government in preventing, preparing for, and responding to oil spills. This report examines the Coast Guard's efforts to avoid unnecessary and wasteful duplication by coordinating with the private sector and others, including federal and state agencies, its plans to buy oil spill response equipment and the new responsibilities the act places on the private sector and the Coast Guard and if these responsibilities call for a shift in emphasis in Coast Guard oil spill response activities

  9. Assessing aquifer storage and recovery feasibility in the Gulf Coastal Plains of Texas

    Directory of Open Access Journals (Sweden)

    W. Benjamin Smith

    2017-12-01

    Full Text Available Study region: The Gulf Coast and Carrizo-Wilcox aquifer systems in the Gulf Coastal Plains of Texas. Study focus: Aquifer storage and recovery is a water storage alternative that is underutilized in Texas, a state with both long periods of drought and high intensity storms. Future water storage plans in Texas almost exclusively rely on surface reservoirs, subject to high evaporative losses. This study seeks to identify sites where aquifer storage and recovery (ASR may be successful, especially in recovery of injected waters, by analyzing publicly-available hydrogeologic data. Transmissivity, hydraulic gradient, well density, depth to aquifer, and depth to groundwater are used in a GIS-based index to determine feasibility of implementing an ASR system in the Gulf Coast and Carrizo-Wilcox aquifer systems. New hydrological insights for the region: Large regions of the central and northern Gulf Coast and the central and southern Carrizo-Wilcox aquifer systems are expected to be hydrologically feasible regions for ASR. Corpus Christi, Victoria, San Antonio, Bryan, and College Station are identified as possible cities where ASR would be a useful water storage strategy. Keywords: Aquifer storage and recovery (ASR, GIS, Gulf coast, Carrizo-Wilcox, Managed aquifer recharge (MAR

  10. Testing geopressured geothermal reservoirs in existing wells. Wells of Opportunity Program final contract report, 1980-1981

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    The geopressured-geothermal candidates for the Wells of Opportunity program were located by the screening of published information on oil industry activity and through direct contact with the oil and gas operators. This process resulted in the recommendation to the DOE of 33 candidate wells for the program. Seven of the 33 recommended wells were accepted for testing. Of these seven wells, six were actually tested. The first well, the No. 1 Kennedy, was acquired but not tested. The seventh well, the No. 1 Godchaux, was abandoned due to mechanical problems during re-entry. The well search activities, which culminated in the acceptance by the DOE of 7 recommended wells, were substantial. A total of 90,270 well reports were reviewed, leading to 1990 wells selected for thorough geological analysis. All of the reservoirs tested in this program have been restricted by one or more faults or permeability barriers. A comprehensive discussion of test results is presented.

  11. Geopressured-geothermal test of the EDNA Delcambre No. 1 well, Tigre Lagoon Field, Vermilion Parish, Louisiana: Analysis of water and dissolved natural gas: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hankind, B.E.; Karkalits, O.C.

    1978-09-01

    The presence of large volumes of hot water (250-425 F) containing dissolved natural gas in the Gulf of Mexico coastal areas at depths of 5,000 to 25,000 feet (the geopressured zone) has been known for several years. Because natural gas and oil from conventional production methods were relatively inexpensive prior to 1973, and because foreign oil was readily available, no economic incentive existed for developing this resource. With the oil embargo and the resulting rapid escalation in prices of oil and gas since 1973, a new urgency exists for examining the economic potential of the geopressured-geothermal resource. The main objective of the research reported here was to determine the volume of gas dissolved in the geopressured water, as well as the qualitative and quantitative composition of the water and the dissolved gas. A further objective was to use an existing shut-in gas well so that drilling time and the attendant costs could be avoided.

  12. Aquifers in coastal reclaimed lands - real world assessments

    Science.gov (United States)

    Saha, A.; Bironne, A.; Vonhögen-Peeters, L.; Lee, W. K.; Babovic, V. M.; Vermeulen, P.; van Baaren, E.; Karaoulis, M.; Blanchais, F.; Nguyen, M.; Pauw, P.; Doornenbal, P.

    2017-12-01

    Climate change and population growth are significant concerns in coastal regions around the world, where more than 30% of the world's population reside. The numbers continue to rise as coastal areas are increasingly urbanized. Urbanization creates land shortages along the coasts, which has spurred coastal reclamation activities as a viable solution. In this study, we focus on these reclamation areas; reclaimed areas in Singapore, and in the Netherlands, and investigate the potential of these reclaimed bodies as artificial aquifers that could attenuate water shortage problems in addition to their original purpose. We compare how the reclamation methods determine the hydrogeological characteristics of these manmade aquifers. We highlight similarities in freshwater lens development in the artificial shallow aquifers under natural recharge under diverse conditions, i.e. tropical and temperate zones, using numerical models. The characteristics and responses of these aquifers with dynamic freshwater-saltwater interface are contrasted against naturally occurring coastal aquifers where equilibrium was disturbed by anthropogenic activities. Finally, we assess the risks associated with subsidence and saltwater intrusion, combining measurements and numerical models, in case these aquifers are planned for Aquifer Storage and Recovery (ASR) or Managed Aquifer Recharge (MAR) strategies. Relative performances of some ASR schemes are simulated and compared in the reclaimed lands.

  13. U.S. DOE Geopressured/Geothermal Program: Final report on well plug and abandonment operations and well site restoration, Louisiana and Texas wells

    Energy Technology Data Exchange (ETDEWEB)

    None

    1994-08-30

    Some of the critical operations conducted during the plugging and abandonment of the three producing wells of the U.S. DOE GEOPRESSURED/GEOTHERL PROGRAM were witnessed by D-O-R Engineering personnel. All operations witnessed by D-O-R personnel were in compliance with the respective state regulations and were conducted as per D-O-R's recommendations to the Department of Energy and their prime contractor, EG&G Idaho. It is our belief that competent cement plugs were left in all three wells. The following describes the work actually witnessed by D-O-R personnel.

  14. 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...

  15. Tracers Detect Aquifer Contamination

    National Research Council Canada - National Science Library

    Enfield, Carl

    1995-01-01

    The EPA's National Laboratory (NRMRL) at Ada, OK, along with the University of Florida and the University of Texas, have developed a tracer procedure to detect the amount of contamination in aquifer formations...

  16. Ogallala Aquifer Mapping Program

    International Nuclear Information System (INIS)

    1984-10-01

    A computerized data file has been established which can be used efficiently by the contour-plotting program SURFACE II to produce maps of the Ogallala aquifer in 17 counties of the Texas Panhandle. The data collected have been evaluated and compiled into three sets, from which SURFACE II can generate maps of well control, aquifer thickness, saturated thickness, water level, and the difference between virgin (pre-1942) and recent (1979 to 1981) water levels. 29 figures, 1 table

  17. Profitability Evaluation of a Hybrid Geothermal and CO2 Sequestration Project for a Coastal Hot Saline Aquifer.

    Science.gov (United States)

    Plaksina, Tatyana; Kanfar, Mohammed

    2017-11-01

    With growing interest in commercial projects involving industrial volume CO2 sequestration, a concern about proper containment and control over the gas plume becomes particularly prominent. In this study, we explore the potential of using a typical coastal geopressured hot saline aquifer for two commercial purposes. The first purpose is to harvest geothermal heat of the aquifer for electricity generation and/or direct use and the second one is to utilize the same rock volume for safe and controlled CO2 sequestration without interruption of heat production. To achieve these goals, we devised and economically evaluated a scheme that recovers operational and capital costs within first 4 years and yields positive internal rate of return of about 15% at the end of the operations. Using our strategic design of well placement and operational scheduling, we were able to achieve in our numerical simulation study the following results. First, the hot water production rates allowed to run a 30 MW organic Rankine cycle plant for 20 years. Second, during the last 10 years of operation we managed to inject into the same reservoir (volume of 0.8 x 109 m3) approximately 10 million ton of the supercritical gas. Third, decades of numerical monitoring the plume after the end of the operations showed that this large volume of CO2 is securely sequestrated inside the reservoir without compromising the caprock integrity.

  18. Profitability Evaluation of a Hybrid Geothermal and CO2 Sequestration Project for a Coastal Hot Saline Aquifer.

    Directory of Open Access Journals (Sweden)

    Plaksina Tatyana

    2017-01-01

    Full Text Available With growing interest in commercial projects involving industrial volume CO2 sequestration, a concern about proper containment and control over the gas plume becomes particularly prominent. In this study, we explore the potential of using a typical coastal geopressured hot saline aquifer for two commercial purposes. The first purpose is to harvest geothermal heat of the aquifer for electricity generation and/or direct use and the second one is to utilize the same rock volume for safe and controlled CO2 sequestration without interruption of heat production. To achieve these goals, we devised and economically evaluated a scheme that recovers operational and capital costs within first 4 years and yields positive internal rate of return of about 15% at the end of the operations. Using our strategic design of well placement and operational scheduling, we were able to achieve in our numerical simulation study the following results. First, the hot water production rates allowed to run a 30 MW organic Rankine cycle plant for 20 years. Second, during the last 10 years of operation we managed to inject into the same reservoir (volume of 0.8 x 109 m3 approximately 10 million ton of the supercritical gas. Third, decades of numerical monitoring the plume after the end of the operations showed that this large volume of CO2 is securely sequestrated inside the reservoir without compromising the caprock integrity.

  19. Epigenetic zonation and fluid flow history of uranium-bearing fluvial aquifer systems, south Texas uranium province. Report of Investigations No. 119

    International Nuclear Information System (INIS)

    Galloway, W.E.

    1982-01-01

    The Oligocene-Miocene fluvial uranium host aquifers of the South Texas uranium province were deposited principally as syndepositionally oxidized sands and muds. Early intrusion of reactive sulfide-enriched waters produced large intrastratal islands of epigenetic sulfidic alteration, which contain isotopically heavy pyrite exhibiting unique replacement textures. The only known reservoir containing such sulfidic waters is the deeply buried Mesozoic carbonate section beneath the thick, geopressured Tertiary basin fill. Thermobaric waters were expulsed upward along major fault zones into shallow aquifers in response to a pressure head generated by compaction and dehydration in the abyssal ground-water regime. Vertical migration of gaseous hydrogen sulfide was less important. Repeated flushing of the shallow aquifers by oxidizing meteoric waters containing anomalous amounts of uranium, selenium, and molybdenum alternating with sulfidic thermobaric waters caused cyclic precipitation and oxidation of iron disulfide. Uranium deposits formed along hydrologically active oxidation interfaces separating epigenetic sulfidic and epigenetic oxidation zones. Multiple epigenetic events are recorded in imperfectly superimposed, multiple mineralization fronts, in regional and local geometric relations between different alteration zones, and in the bulk matrix geochemistry and mineralogy of alteration zones. The dynamic mineralization model described in this report may reflect processes active in many large, depositionally active basins

  20. Modelling the salinization of a coastal lagoon-aquifer system

    Science.gov (United States)

    Colombani, N.; Mastrocicco, M.

    2017-08-01

    In this study, a coastal area constituted by alternations of saline-brackish lagoons and freshwater bodies was studied and modelled to understand the hydrological processes occurring between the lagoons, the groundwater system of the Po River Delta (Italy) and the Adriatic Sea. The contribution of both evaporation and anthropogenic factors on groundwater salinization was assessed by means of soil, groundwater and surface water monitoring. Highresolution multi-level samplers were used to capture salinity gradients within the aquifer and surface water bodies. Data were employed to calibrate a density-dependent numerical transport model implemented with SEAWAT code along a transect perpendicular to the coast line. The results show that the lagoon is hydraulically well connected with the aquifer, which provides the major source of salinity because of the upcoming of paleo-seawater from the aquitard laying at the base of the unconfined aquifer. On the contrary, the seawater (diluted by the freshwater river outflow) creates only a limited saltwater wedge. The increase in groundwater salinity could be of serious concern, especially for the pinewood located in the dune near the coast, sensitive to salinity increases. This case study represents an interesting paradigm for other similar environmental setting, where the assumption of classical aquifer salinization from a saltwater wedge intruding from the sea is often not representative of the actual aquifer’s salinization mechanisms.

  1. Effects of Sea Level Rise on Groundwater Flow Paths in a Coastal Aquifer System

    Science.gov (United States)

    Morrissey, S. K.; Clark, J. F.; Bennett, M. W.; Richardson, E.; Stute, M.

    2008-05-01

    Changes in groundwater flow in the Floridan aquifer system, South Florida, from the rise in sea level at the end of the last glacial period may be indicative of changes coastal aquifers will experience with continued sea level rise. As sea level rises, the hydraulic head near the coast increases. Coastal aquifers can therefore experience decreased groundwater gradients (increased residence times) and seawater intrusion. Stable isotopes of water, dissolved noble gas temperatures, radiocarbon and He concentrations were analyzed in water collected from 68 wells in the Floridan aquifer system throughout South Florida. Near the recharge area, geochemical data along groundwater flow paths in the Upper Floridan aquifer show a transition from recently recharged groundwater to glacial-aged water. Down gradient from this transition, little variation is apparent in the stable isotopes and noble gas recharge temperatures, indicating that most of the Upper Floridan aquifer contains groundwater recharged during the last glacial period. The rapid 120-meter rise in sea level marking the end of the last glacial period increased the hydraulic head in the Floridan aquifer system near the coast, slowing the flow of groundwater from the recharge area to the ocean and trapping glacial-aged groundwater. The raised sea level also flooded half of the Florida platform and caused seawater to intrude into the Lower Floridan. This circulation of seawater in the Lower Floridan continues today as our data indicate that the groundwater is similar to modern seawater with a freshwater component entering vertically from the recharge area to the Upper Floridan.

  2. Developing Methods For Linking Surficial Aquifers With Localized Rainfall Data

    Science.gov (United States)

    Lafrenz, W. B.; van Gaalen, J. F.

    2008-12-01

    Water level hydrographs of the surficial aquifer can be evaluated to identify both the cause and consequence of water supply development. Rainfall, as a source of direct recharge and as a source of delayed or compounded recharge, is often the largest influence on surficial aquifer water level responses. It is clear that proximity of the rain gauge to the observation well is a factor in the degree of correlation, but in central Florida, USA, rainfall patterns change seasonally, with latitude, and with distance from the coast . Thus, for a location in central Florida, correlation of rain events with observed hydrograph responses depends on both distance and direction from an observation well to a rain gauge. In this study, we examine the use of extreme value analysis as a method of selecting the best rainfall data set for describing a given surficial aquifer monitor well. A surficial aquifer monitor well with a substantial suite of data is compared to a series of rainfall data sets from gauges ranging from meters to tens of kilometers in distance from the monitor well. The gauges vary in a wide range of directions from the monitor well in an attempt to identify both a method for rainfall gauge selection to be associated with the monitor well. Each rainfall gauge is described by a correlation coefficient with respect to the surficial aquifer water level data.

  3. Hydrogeology, water quality, and microbial assessment of a coastal alluvial aquifer in western Saudi Arabia: potential use of coastal wadi aquifers for desalination water supplies [Hydrogéologie, qualité de l’eau et évaluation microbienne d’un aquifère côtier alluvial dans l’Ouest de l’Arabie Saoudite: utilisation potentielle des aquifères côtiers des oueds pour l’alimentation en eau après désalinisation] [Hidrogeologia, qualidade da água e avaliação microbiológica de um aquífero costeiro no oeste da Arábia Saudita: uso potencial de aquíferos de wadi costeiros para dessalinização de águas destinadas a abastecimento] [Hidrogeología, calidad de agua y evaluación microbiana de un acuífero costero aluvial en Arabia Saudita occidental: uso potencial de acuíferos costeros uadis para la desalinización de los abastecimientos de agua

    KAUST Repository

    Missimer, Thomas M.; Hoppe-Jones, Christiane; Jadoon, Khan; Li, Dong; Almashharawi, Samir

    2014-01-01

    into two sand-and-gravel aquifers at the coast, each with high productivity (transmissivity = 42,000 m2/day). This aquifer system becomes confined near the coast and contains hypersaline water. The hydrogeology of Wadi Wasimi shows that two

  4. 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

  5. Arsenic levels in groundwater aquifer

    African Journals Online (AJOL)

    Miodrag Jelic

    resistance (ρ); dielectric constant (ε); magnetic permeability (η); electrochemical activity ..... comprises grey sands of different particle size distribution ..... groundwater: testing pollution mechanisms for sedimentary aquifers in. Bangladesh.

  6. Isotopes to Study the coastal aquifer plain, Cap Bon, Tunisia

    International Nuclear Information System (INIS)

    Ben Hamouda, M. F.; Zouari, Kamel; Tarhouni, J.; Gaye, C.B.; Oueslati, M.N.

    2005-01-01

    The study area is located in the northeastern part of Tunisia about 60 km south of the Tunis city. It is bounded by the Gulf of Haematite in the East, Djebel Sidi Aberahmane in the West, The town of Nabeul in the south and the area of the town Kelibia in the north. The landscape is a coastal plain slightly sloping (3%) towards the sea. The groundwater of the Oriental coast aquifer system occurs mainly at two levels, a shallow aquifer up to depths of about 50 m whose reservoir is consisted by sediments of the Plio quaternary and a deep aquifer between about 150 and 400 m located in the sand stone formations of Miocene of the anticline of Djebel Sidi Abderrahmene. The climate of the region is semi-arid to sub-humid and of Mediterranean type. There are no perennial rivers in this region; but intense storms occasionally cause surface runoff, which is discharged by the oueds. The study is related to a technical cooperation project with the International Atomic Energy Agency, Vienna, Austria, aimed at the use of isotope techniques to study the seawater intrusion into the coastal aquifers of Cap Bon in Tunisia. In this regard, a better understanding of the recharge and flow regime as well as the origin or salinity of the groundwater was required. To reach this goal, isotope and geochemical investigations were carried out. Water samples were taken from wells, boreholes from deep and shallow aquifer of the Oriental coastal aquifer located between Beni Khiar in the south and Kelibia in the north. The samples were analysed for their chemical and isotopic compositions (18O, 2H, 3H, 13C, 14C, 34S). In the following, the results of these analyses are presented and discussed in terms of the recharge and flow regime of the groundwater and the origin and evolution of its salinity. The results of geochemical and isotopic studies have shown that the groundwater is very eterogeneous and suggest the aquifer is replenished by recent water coming from direct infiltration from rain. At

  7. 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...

  8. Changes in Chemical and Isotopic Composition of Groundwater during Long-Term Pumping Test in Brestovica Karst Aquifer

    International Nuclear Information System (INIS)

    Mezga, Kim; Urbanc, Janko

    2011-01-01

    The main aim of the experimental pumping test, which was carried out in the dry summer period in August 2008 for 30 days, was to assess the groundwater resource quantity which could be pumped at the time of the highest water needs for the Slovene Coast and Karst areas. Further, we wanted to test the chemical status of groundwater to assure its suitability for further use and to assess the influence of the Soca River aquifer on this karst aquifer

  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

    , litany of names for the various formations, lithofacies, and aquifer systems identified within these basins. Despite these nomenclatural problems, available data show that most basins contain similar sequences of deposits and share similar geologic histories dominated by glacio-eustatic sea-level fluctuations, and overprinted by syndepositional and postdepositional tectonic deformation. Impermeable, indurated mid-Tertiary units typically form the base of each siliciclastic groundwater basin. These units are overlain by stacked sequences of Pliocene to Holocene interbedded marine, paralic, fluvial, and alluvial sediment (weakly indurated, folded, and fractured) that commonly contain the historically named "80-foot sand," "200-foot sand," and "400-foot gravel" in the upper part of the section. An unconformity, cut during the latest Pleistocene lowstand (??18O stage 2; ca. 18 ka), forms a major sequence boundary that separates these units from the overlying Holocene fluvial sands and gravels. Unconfined aquifers occur in amalgamated coarse facies near the bounding mountains (forebay area). These units are inferred to become lithologically more complex toward the center of the basins and coast line, where interbedded permeable and low-permeability alluvial, fluvial, paralic, and marine facies contain confined aquifers (pressure area). Coastal bounding faults limit intrabasin and/or interbasin flow in parts of many basins. ?? 2009 Geological Society of America.

  10. AQUIFER IN AJAOKUTA, SOUTHWESTERN NIGERIA

    African Journals Online (AJOL)

    2005-03-08

    Mar 8, 2005 ... To establish the feasibility of water supply in a basement complex area ofAjaokuta, Southwestern Nigeria, pumping test results were used to investigate the storage properties and groundwater potential of the aquifer. The aquifer system consists of weathered and weathered/fractured zone of decomposed ...

  11. Coast Guard Compass

    Science.gov (United States)

    looks on as Adm. Charles Ray thanks Adm. Chuck Michel for his service as the 30th vice commandant of the commandant Adm. Charles W. Ray relieved Adm. Charles D. Michel as vice commandant of the U.S. Coast Guard by . Following graduation and commissioning as an officer in the Coast Guard, Wright will be heading to the

  12. Oceans and Coasts

    Science.gov (United States)

    An overview of EPA’s oceans, coasts, estuaries and beaches programs and the regulatory (permits/rules) and non-regulatory approaches for managing their associated environmental issues, such as water pollution and climate change.

  13. US west coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aerial surveys are conducted along the US west coast to determine distribution and abundance of endangered leatherback turtles (Dermochelys coriacea), loggerhead...

  14. aquifer in ajaokuta, southwestern nigeria

    African Journals Online (AJOL)

    2005-03-08

    Mar 8, 2005 ... (1969) straight line method (observation well) of draw-down analysis in an unconfined aquifer (B=1) yield ... April) and a short wet season (May-September). .... DECOMPOSED. GRANITIC ROCK WITH. QUARTZ VEINS. 13.

  15. The Marlborough Deep Wairau Aquifer sustainability review 2008 : isotopic indicators

    International Nuclear Information System (INIS)

    Morgenstern, U.; van der Raaij, R.W.; Trompetter, V.; McBeth, K.

    2008-01-01

    The Deep Wairau Aquifer (DWA) consists of several relatively thin water bearing layers at depths generally greater than 150 m separated by thick confining layers and was therefore thought to be relatively isolated from surface hydrological processes, with little pumping induced effects on spring flows and shallow aquifers. However, because the DWA partially underlies fully allocated shallower Southern Valleys Aquifers it is critical to understand the dynamics (recharge, flow) of the DWA. Recent aquifer testing revealed that the DWA is hydraulically linked to the Southern Valley Benmorven Aquifer and that most wells penetrating the DWA are hydraulically linked. The aquifers of the Wairau Plain are formed by a series of glacial and alluvial outwash deposits laid down by the Wairau River. Bore logs indicate that the aquifer contains thin water-bearing layers within the mixed strata. These layers come under artesian pressure towards the east. The Wairau Gravels are overlain by a sequence of glacial outwash and fluvial gravels interspersed with marine deposits. Immediately above the Wairau Gravels lies the Speargrass Formation consisting of poorly sorted glacial outwash gravels, sand and clay deposits. This formation has greater permeability than the Wairau Gravels. Above the Speargrass Formation lie highly permeable postglacial fluvial gravels, sand and silt deposits from the Wairau and tributary rivers known as the Rapaura Formation. Towards the coast, the alluvial gravels are overlain by marine and estuarine deposits of sand, silt and clay known as the Dillons Point Formation. Chemistry and isotope samples were analysed over time from various DWA wells to obtain information on changes in source and age of water with continued abstraction. All DWA water samples are tritium-free indicating that there is no young water influx yet intercepted by any of the sampled wells. Radiocarbon repeat measurements indicate that the water source is changing towards older water with

  16. EPA Region 1 Sole Source Aquifers

    Science.gov (United States)

    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 drinking water for a given aquifer service area; that is, an aquifer which is needed to supply 50% or more of the drinking water for the area and for which there are no reasonable alternative sources should the aquifer become contaminated.The aquifers were defined by a EPA hydrogeologist. Aquifer boundaries were then drafted by EPA onto 1:24000 USGS quadrangles. For the coastal sole source aquifers the shoreline as it appeared on the quadrangle was used as a boundary. Delineated boundaries were then digitized into ARC/INFO.

  17. Estimating Groundwater Mounding in Sloping Aquifers for Managed Aquifer Recharge.

    Science.gov (United States)

    Zlotnik, Vitaly A; Kacimov, Anvar; Al-Maktoumi, Ali

    2017-11-01

    Design of managed aquifer recharge (MAR) for augmentation of groundwater resources often lacks detailed data, and simple diagnostic tools for evaluation of the water table in a broad range of parameters are needed. In many large-scale MAR projects, the effect of a regional aquifer base dip cannot be ignored due to the scale of recharge sources (e.g., wadis, streams, reservoirs). However, Hantush's (1967) solution for a horizontal aquifer base is commonly used. To address sloping aquifers, a new closed-form analytical solution for water table mound accounts for the geometry and orientation of recharge sources at the land surface with respect to the aquifer base dip. The solution, based on the Dupiuit-Forchheimer approximation, Green's function method, and coordinate transformations is convenient for computing. This solution reveals important MAR traits in variance with Hantush's solution: mounding is limited in time and space; elevation of the mound is strongly affected by the dip angle; and the peak of the mound moves over time. These findings have important practical implications for assessment of various MAR scenarios, including waterlogging potential and determining proper rates of recharge. Computations are illustrated for several characteristic MAR settings. © 2017, National Ground Water Association.

  18. 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.

  19. Geohydrolic studies of Gulf Coast interior salt domes

    International Nuclear Information System (INIS)

    Smith, C.G. Jr.

    1977-01-01

    Disposal of high-level radioactive wastes in Gulf Coast salt domes requires that the cavities be free from groundwater dissolution for 250,000 years. Salinity variations of groundwater near selected domes were investigated. Saline groundwater anomalies (saline plumes) in aquifers pierced or uplifted by the dome may be the result of salt solution by groundwater. In the Northeast Texas salt dome basin electric logs of oil and gas wells have been used to estimate groundwater salinities in aquifers near selected domes. Thus far, the analyses have revealed saline groundwater anomalies around 4 of the 9 domes studied. Estimates of the rate of salt dissolution from domes associated with saline groundwater plumes indicate that less than 30 meters of salt will be removed from the upper surfaces of the dome in 250,000 years. Thus, these preliminary studies show that even apparently unstable domes may be sufficiently stable to serve as waste disposal sites. 6 figures

  20. South Oregon Coast Reinforcement.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1998-05-01

    The Bonneville Power Administration is proposing to build a transmission line to reinforce electrical service to the southern coast of Oregon. This FYI outlines the proposal, tells how one can learn more, and how one can share ideas and opinions. The project will reinforce Oregon`s south coast area and provide the necessary transmission for Nucor Corporation to build a new steel mill in the Coos Bay/North Bend area. The proposed plant, which would use mostly recycled scrap metal, would produce rolled steel products. The plant would require a large amount of electrical power to run the furnace used in its steel-making process. In addition to the potential steel mill, electrical loads in the south Oregon coast area are expected to continue to grow.

  1. Aquifers Characterization and Productivity in Ellala Catchment ...

    African Journals Online (AJOL)

    user

    Aquifers Characterization and Productivity in Ellala Catchment, Tigray, ... using geological and hydrogeological methods in Ellala catchment (296.5km. 2. ) ... Current estimates put the available groundwater ... Aquifer characterization takes into.

  2. Geopressure and Trap Integrity Predictions from 3-D Seismic Data: Case Study of the Greater Ughelli Depobelt, Niger Delta Pressions de pores et prévisions de l’intégrité des couvertures à partir de données sismiques 3D : le cas du grand sous-bassin d’Ughelli, Delta du Niger

    Directory of Open Access Journals (Sweden)

    Opara A.I.

    2012-05-01

    Full Text Available The deep drilling campaign in the Niger Delta has demonstrated the need for a detailed geopressure and trap integrity (drilling margin analysis as an integral and required step in prospect appraisal. Pre-drill pore pressure prediction from 3-D seismic data was carried out in the Greater Ughelli depobelt, Niger Delta basin to predict subsurface pressure regimes and further applied in the determination of hydrocarbon column height, reservoir continuity, fault seal and trap integrity. Results revealed that geopressured sedimentary formations are common within the more prolific deeper hydrocarbon reserves in the Niger Delta basin. The depth to top of mild geopressure (0.60 psi/ft ranges from about 10 000 ftss to over 30 000 ftss. The distribution of geopressures shows a well defined trend with depth to top of geopressures increasing towards the central part of the basin. This variation in the depth of top of geopressures in the area is believed to be related to faulting and shale diapirism, with top of geopressures becoming shallow with shale diapirism and deep with sedimentation. Post-depositional faulting is believed to have controlled the configuration of the geopressure surface and has played later roles in modifying the present day depth to top of geopressures. In general, geopressure in this area is often associated with simple rollover structures bounded by growth faults, especially at the hanging walls, while hydrostatic pressures were observed in areas with k-faults and collapsed crested structures. Les campagnes de forages profonds dans le delta du Niger ont démontré la nécessité d’une analyse détaillée des surpressions et de l’intégrité des structures pour évaluer correctement les prospects. La prédiction des pressions interstitielles a pu être réalisée ici avant forage à partir de données sismiques 3-D du grand sous-bassin d’Ughelli, dans le delta du Niger. Ce travail a permis de prévoir les régimes de pression du

  3. Geopressured-Geothermal Drilling and Testing Plan, Volume II, Testing Plan; Dow Chemical Co. - Dept. of Energy Dow-DOE Sweezy No. 1 Well, Vermilion Parish, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-02-01

    The Dow/D.O.E. L. R. Sweezy No. 1 geopressured geothermal production well was completed in August of 1981. The well was perforated and gravel packed in approximately 50 feet of sand from 13,344 feet to 13,395 feet. Permeabilities of 6 to 914 millidarcies were measured with porosity of 25 to 36%. Static surface pressure after well clean-up was 5000 psi. At 1000 B/D flow rate the drawdown was 50 psi. The water produced in clean-up contained 100,000 ppm TDS. This report details the plan for testing this well with the goal of obtaining sufficient data to define the total production curve of the small, 939 acre, reservoir. A production time of six to nine months is anticipated. The salt water disposal well is expected to be completed and surface equipment installed such that production testing will begin by April 1, 1982. The program should be finished and reports written by February 28, 1983. The brine will be produced from the No.1 well, passed through a separator where the gas is removed, then reinjected into the No.2 (SWD) well under separator pressure. Flow rates of up to 25,000 B/D are expected. The tests are divided into a two-week short-term test and six to nine-month long-term tests with periodic downhole measurement of drawdown and buildup rates. Data obtained in the testing will be relayed by phoneline computer hookup to Otis Engineering in Dallas, Texas, where the reservoir calculations and modeling will be done. At the point where sufficient data has been obtained to reach the objectives of the program, production will be ended, the wells plugged and abandoned, and a final report will be issued.

  4. Maine coast winds

    Energy Technology Data Exchange (ETDEWEB)

    Avery, Richard

    2000-01-28

    The Maine Coast Winds Project was proposed for four possible turbine locations. Significant progress has been made at the prime location, with a lease-power purchase contract for ten years for the installation of turbine equipment having been obtained. Most of the site planning and permitting have been completed. It is expect that the turbine will be installed in early May. The other three locations are less suitable for the project, and new locations are being considered.

  5. Aquifer thermal energy stores in Germany

    International Nuclear Information System (INIS)

    Kabus, F.; Seibt, P.; Poppei, J.

    2000-01-01

    This paper describes the state of essential demonstration projects of heat and cold storage in aquifers in Germany. Into the energy supply system of the buildings of the German Parliament in Berlin, there are integrated both a deep brine-bearing aquifer for the seasonal storage of waste heat from power and heat cogeneration and a shallow-freshwater bearing aquifer for cold storage. In Neubrandenburg, a geothermal heating plant which uses a 1.200 m deep aquifer is being retrofitted into an aquifer heat storage system which can be charged with the waste heat from a gas and steam cogeneration plant. The first centralised solar heating plant including an aquifer thermal energy store in Germany was constructed in Rostock. Solar collectors with a total area of 1000m 2 serve for the heating of a complex of buildings with 108 flats. A shallow freshwater-bearing aquifer is used for thermal energy storage. (Authors)

  6. Geochemical approach of the salinization mechanisms of coastal aquifers - 14C - 226Ra chronologies

    International Nuclear Information System (INIS)

    Barbecot, F.

    1999-11-01

    Through time, coastal aquifers which constitute a great part of available fresh water resources from sedimentary basins in France, were submitted to changes in hydraulic gradients and hydrodynamic properties mainly due to discharge/recharge phases in response to sea level variations and/or anthropic forcing. Performed in the framework of the European program PALAEAUX ('Management of coastal aquifers in Europe, paleo-waters and natural controls'), this work aimed to understand the salinization process originating from the recharge/discharge conditions and recognized in three study aquifers: the calcareous Dogger aquifers along the Channel (Caen area), and the Atlantic coast (Marais Poitevin), and the Astian sandy aquifer (Cap d'Agde). Besides the conventional hydrogeological and hydrochemical methods, the main tools used are those of isotope geochemistry. For the three sites, the modern, fresh groundwaters are marked by the anthropisation of the recharge area. The evolution of isotopic signatures along a flow path depending on the mineralogy of the aquifer matrix, is linked to water-rock interactions such as cation exchange, and equilibrium with aluminosilicates. For the three study sites, the modern fresh groundwaters are marked by the anthropisation of the recharge area. The evolution of isotopic signatures along a flow path depending on the mineralogy of the aquifer matrix, is linked to water-rock interactions such as cation exchange, and equilibrium with aluminosilicates. Residence times of these fresh groundwater are from Present (Atlantic site) up to the 14 C detection limit (Channel site). Groundwater of the Astian aquifer belongs to Holocene, as determined by both 14 C and 226 Ra. From Present to 3 ka, 14 C and 226 Ra ages are coherent. Beyond, the discrepancy observed can be associated to the under-estimation of in- situ 226 Ra production, but more likely, to the 'buffer' effect of the matrix with respect to the 14 C isotopic equilibration. The salty waters

  7. Stimulation of reductive dechlorination of tetrachloroethane in anaerobic aquifer microcosms by addition of short-chain organic acids or alcohols

    International Nuclear Information System (INIS)

    Gibson, S.A.; Sewell, G.W.

    1992-01-01

    Although the ecological and public health risk associated with tetrachloroethene (PCE) contamination may be the most severe when spills affect groundwater, little is known about the environmental conditions necessary to initiate and sustain dehalogenation activity in contaminated aquifers. This study was done with core material collected from a site impacted by both aviation gasoline and chloroethenes at a Coast Guard Air Station at Traverse City, Michigan. The effect of the addition of common fermentation products on the dehalogenation of tetrachloroethene was studied in methanogenic slurries made with aquifer solids. Lactate, propionate, crotonate, butyrate, and ethanol stimulated dehalogenation activity, while acetate, methanol, and isopropanol did not

  8. Arsenic, microbes and contaminated aquifers

    Science.gov (United States)

    Oremland, Ronald S.; Stolz, John F.

    2005-01-01

    The health of tens of millions of people world-wide is at risk from drinking arsenic-contaminated well water. In most cases this arsenic occurs naturally within the sub-surface aquifers, rather than being derived from identifiable point sources of pollution. The mobilization of arsenic into the aqueous phase is the first crucial step in a process that eventually leads to human arsenicosis. Increasing evidence suggests that this is a microbiological phenomenon.

  9. Application and evaluation of electromagnetic methods for imaging saltwater intrusion in coastal aquifers: Seaside Groundwater Basin, California

    Science.gov (United States)

    Nenna, Vanessa; Herckenrather, Daan; Knight, Rosemary; Odlum, Nick; McPhee, Darcy

    2013-01-01

    Developing effective resource management strategies to limit or prevent saltwater intrusion as a result of increasing demands on coastal groundwater resources requires reliable information about the geologic structure and hydrologic state of an aquifer system. A common strategy for acquiring such information is to drill sentinel wells near the coast to monitor changes in water salinity with time. However, installation and operation of sentinel wells is costly and provides limited spatial coverage. We studied the use of noninvasive electromagnetic (EM) geophysical methods as an alternative to installation of monitoring wells for characterizing coastal aquifers. We tested the feasibility of using EM methods at a field site in northern California to identify the potential for and/or presence of hydraulic communication between an unconfined saline aquifer and a confined freshwater aquifer. One-dimensional soundings were acquired using the time-domain electromagnetic (TDEM) and audiomagnetotelluric (AMT) methods. We compared inverted resistivity models of TDEM and AMT data obtained from several inversion algorithms. We found that multiple interpretations of inverted models can be supported by the same data set, but that there were consistencies between all data sets and inversion algorithms. Results from all collected data sets suggested that EM methods are capable of reliably identifying a saltwater-saturated zone in the unconfined aquifer. Geophysical data indicated that the impermeable clay between aquifers may be more continuous than is supported by current models.

  10. Aquifer thermal-energy-storage modeling

    Science.gov (United States)

    Schaetzle, W. J.; Lecroy, J. E.

    1982-09-01

    A model aquifer was constructed to simulate the operation of a full size aquifer. Instrumentation to evaluate the water flow and thermal energy storage was installed in the system. Numerous runs injecting warm water into a preconditioned uniform aquifer were made. Energy recoveries were evaluated and agree with comparisons of other limited available data. The model aquifer is simulated in a swimming pool, 18 ft by 4 ft, which was filled with sand. Temperature probes were installed in the system. A 2 ft thick aquifer is confined by two layers of polyethylene. Both the aquifer and overburden are sand. Four well configurations are available. The system description and original tests, including energy recovery, are described.

  11. Hydrochemistry of New Zealand's aquifers

    International Nuclear Information System (INIS)

    Rosen, M.R.

    2001-01-01

    Groundwater chemistry on a national scale has never been studied in New Zealand apart from a few studies on nitrate concentrations and pesticides. These studies are covered in Chapter 8 of this book. However general studies of groundwater chemistry, groundwater-rock interaction and regional characteristics of water quality have not been previously addressed in much detail. This is partly because New Zealand aquifers are relatively small on a world scale and are geologically and tectonically diverse (see Chapter 3). But New Zealand has also recently lacked a centralised agency responsible for groundwater quality, and therefore, no national assessments have been undertaken. In recent years, the Institute of Geological and Nuclear Sciences has managed a programme of collecting and analysing the groundwater chemistry of key New Zealand aquifers. This programme is called the National Groundwater Monitoring Programme (NGMP) and is funded by the New Zealand Public Good Science Fund. The programme started in 1990 using only 22 wells, with four regional authorities of the country participating. The NGMP now includes all 15 regional and unitary authorities that use groundwater and over 100 monitoring sites. The NGMP is considered a nationally significant database by the New Zealand Foundation for Research Science and Technology. The NGMP allows a national comparison of aquifer chemistries because the samples are all analysed at one laboratory in a consistent manner and undergo stringent quality control checks. Poor quality analyses are thus minimised. In addition, samples are collected quarterly so that long-term seasonal trends in water quality can be analysed, and the effects of changes in land use and the vulnerability of aquifers to contaminant leaching can be assessed. This chapter summarises the water quality data collected for the NGMP over the past 10 years. Some records are much shorter than others, but most are greater than three years. Additional information is

  12. An evaluation of aquifer intercommunication between the unconfined and Rattlesnake Ridge aquifers on the Hanford Site

    International Nuclear Information System (INIS)

    Jensen, E.J.

    1987-10-01

    During 1986, Pacific Northwest Laboratory conducted a study of a portion of the Rattlesnake Ridge aquifer (confined aquifer) that lies beneath the B Pond - Gable Mountain Pond area of the Hanford Site. The purpose was to determine the extent of intercommunication between the unconfined aquifer and the uppermost regionally extensive confined aquifer, referred to as the Rattlesnake Ridge aquifer. Hydraulic head data and chemical data were collected from the ground water in the study area during December 1986. The hydraulic head data were used to determine the effects caused by water discharged to the ground from B Pond on both the water table of the unconfined aquifer and the potentiometric surface of the confined aquifer. The chemical data were collected to determine the extent of chemical constituents migrating from the unconfined aquifer to the confined aquifer. Analysis of chemical constituents in the Rattlesnake Ridge aquifer demonstrated that communication between the unconfined and confined aquifers had occurred. However, the levels of contaminants found in the Rattlesnake Ridge aquifer during this study were below the DOE Derived Concentration Guides

  13. Aquifer Characterization and Groundwater Potential Assessment

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Keywords: Aquifer Characterization, Groundwater Potential, Electrical Resistivity, Lithologic Logs ... State Water Corporation currently cannot meet the daily water ... METHOD OF STUDY ... sections which were constrained with the available.

  14. Longshore sediment transport along the Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Nayak, B.U.

    Coast. Maharashtra Coast and the part between Pondicherry and Point Calimere in Tamilnadu, show negligible order of annual net transport. Annual net transport along the east coast is in north and along the west coast in south but for South Gujarat Coast....

  15. Indian Ocean coasts, coastal ecology

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.

    stream_size 9 stream_content_type text/plain stream_name Encycl_Coast_Sci_2005_546.pdf.txt stream_source_info Encycl_Coast_Sci_2005_546.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  16. Seawater intrusion in karstic, coastal aquifers: Current challenges and future scenarios in the Taranto area (southern Italy).

    Science.gov (United States)

    De Filippis, Giovanna; Foglia, Laura; Giudici, Mauro; Mehl, Steffen; Margiotta, Stefano; Negri, Sergio Luigi

    2016-12-15

    Mediterranean areas are characterized by complex hydrogeological systems, where management of freshwater resources, mostly stored in karstic, coastal aquifers, is necessary and requires the application of numerical tools to detect and prevent deterioration of groundwater, mostly caused by overexploitation. In the Taranto area (southern Italy), the deep, karstic aquifer is the only source of freshwater and satisfies the main human activities. Preserving quantity and quality of this system through management policies is so necessary and such task can be addressed through modeling tools which take into account human impacts and the effects of climate changes. A variable-density flow model was developed with SEAWAT to depict the "current" status of the saltwater intrusion, namely the status simulated over an average hydrogeological year. Considering the goals of this analysis and the scale at which the model was built, the equivalent porous medium approach was adopted to represent the deep aquifer. The effects that different flow boundary conditions along the coast have on the transport model were assessed. Furthermore, salinity stratification occurs within a strip spreading between 4km and 7km from the coast in the deep aquifer. The model predicts a similar phenomenon for some submarine freshwater springs and modeling outcomes were positively compared with measurements found in the literature. Two scenarios were simulated to assess the effects of decreased rainfall and increased pumping on saline intrusion. Major differences in the concentration field with respect to the "current" status were found where the hydraulic conductivity of the deep aquifer is higher and such differences are higher when Dirichlet flow boundary conditions are assigned. Furthermore, the Dirichlet boundary condition along the coast for transport modeling influences the concentration field in different scenarios at shallow depths; as such, concentration values simulated under stressed conditions

  17. Diagnosis of the Ghiss Nekor aquifer in order to elaborate the aquifer contract

    Science.gov (United States)

    Baite, Wissal; Boukdir, A.; Zitouni, A.; Dahbi, S. D.; Mesmoudi, H.; Elissami, A.; Sabri, E.; Ikhmerdi, H.

    2018-05-01

    The Ghiss-Nekor aquifer, located in the north-east of the action area of the ABHL, plays a strategic role in the drinkable water supply of the city of Al Hoceima and of the neighboring urban areas. It also participates in the irrigation of PMH. However, this aquifer has problems such as over-exploitation and pollution. In the face of these problems, the only Solution is the establishment of a new mode of governance, which privileges the participation, the involvement and the responsibility of the actors concerned in a negotiated contractual framework, namely the aquifer contract. The purpose of this study is to diagnose the current state of the Ghiss Nekor aquifer, the hydrogeological characterization of the aquifer, the use of the waters of the aquifer, the Problem identification and the introduction of the aquifer contract, which aims at the participatory and sustainable management of underground water resources in the Ghiss- Nekor plain, to ensure sustainable development.

  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. Estimating Aquifer Properties Using Sinusoidal Pumping Tests

    Science.gov (United States)

    Rasmussen, T. C.; Haborak, K. G.; Young, M. H.

    2001-12-01

    We develop the theoretical and applied framework for using sinusoidal pumping tests to estimate aquifer properties for confined, leaky, and partially penetrating conditions. The framework 1) derives analytical solutions for three boundary conditions suitable for many practical applications, 2) validates the analytical solutions against a finite element model, 3) establishes a protocol for conducting sinusoidal pumping tests, and 4) estimates aquifer hydraulic parameters based on the analytical solutions. The analytical solutions to sinusoidal stimuli in radial coordinates are derived for boundary value problems that are analogous to the Theis (1935) confined aquifer solution, the Hantush and Jacob (1955) leaky aquifer solution, and the Hantush (1964) partially penetrated confined aquifer solution. The analytical solutions compare favorably to a finite-element solution of a simulated flow domain, except in the region immediately adjacent to the pumping well where the implicit assumption of zero borehole radius is violated. The procedure is demonstrated in one unconfined and two confined aquifer units near the General Separations Area at the Savannah River Site, a federal nuclear facility located in South Carolina. Aquifer hydraulic parameters estimated using this framework provide independent confirmation of parameters obtained from conventional aquifer tests. The sinusoidal approach also resulted in the elimination of investigation-derived wastes.

  20. 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.

  1. Study of the leakage between two aquifers in Hermosillo, Mexico, using environmental isotopes

    International Nuclear Information System (INIS)

    Payne, B.R.; Quijano, L.; Latorre, D.C.

    1980-01-01

    The Coast of Hermosillo is located in the Gulf of California, Mexico. It is a Quaternary alluvial plain of continental origin. Underlying these deposits is a layer of blue clay about 100m thick which imposes confinement to a deep aquifer in basaltic and pyroclastic rocks. Oxygen-18 and deuterium data support the occurrence of an upwardsleakage. The amount of the leakage was evaluated, on the basis of 14 C data, to a maximum of 20% of the water pumped by the irrigation wells in the upper aquifer. The stable isotope data also support the occurrence of sea-water intrusion by preferential channels in the south and in the area of Kino Bay. (author)

  2. The effects of the 2004 tsunami on a coastal aquifer in Sri Lanka

    DEFF Research Database (Denmark)

    Vithanage, Meththika Suharshini; Engesgaard, Peter Knudegaard; Villholth, Karen G.

    2012-01-01

    ) of the groundwater were carried out monthly from October 2005 to August 2007. The aquifer system and tsunami saltwater intrusion were modeled using the variable-density flow and solute transport code HST3D to understand the tsunami plume behavior and estimate the aquifer recovery time. EC values reduced as a result...... on groundwater in coastal areas. Field investigations on the east coast of Sri Lanka were carried out along a transect located perpendicular to the coastline on a 2.4 km wide sand stretch bounded by the sea and a lagoon. Measurements of groundwater table elevation and electrical conductivity (EC...... of the monsoonal rainfall following the tsunami with a decline in reduction rate during the dry season. The upper part of the saturated zone (down to 2.5 m) returned to freshwater conditions (EC

  3. Hydraulic barrier against seawater intrusion in the main aquifer of Delta del Llobregat

    International Nuclear Information System (INIS)

    Ortuno Gobern, F.; Ninerola Pla, J. M.; Fraile, J.; Juarez, I.; Molinero Huguet, J.; Arcos, D.; Pitarch, J. L.

    2009-01-01

    The main aquifer of Delta del Llobregat (Barcelona, Spain) is affected by seawater intrusion from 1970. For stopping its advance, the Catalan Water Agency is carrying out the construction of a positive hydraulic barrier through the injection of water in 14 wells. This is the first project of these characteristic that it is carried out in Spain and pioneer in Europe. The barrier elevates the groundwater level of the aquifer near the coast and avoids that the seawater penetrates inland, using reclaimed water of Baix Llobregat WWTP with several treatments. The first phase brings already more than 2 years of functioning, with highly positive results since a substantial improvement of the quality of the groundwater has been observed. The second phase is at present under construction. (Author)

  4. 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.

  5. Andrew spares Florida Coast

    Science.gov (United States)

    Bush, Susan

    When geologists heard of the intensity of Hurricane Andrew, which struck the Florida coast on August 25 and then moved on to southern Louisiana, they were expecting the same kinds of coastal damage that Hurricane Hugo brought to the Caribbean and Carolina shores in 1989. Both storms were category 4 hurricanes, having winds of 131-155 mph and surges of 13-18 feet. However, the coastal damage never materialized, leaving geologists to analyze the factors that lessened the impact of the storm. “For minimum coastal damage, you couldn't have designed a better storm,” said Orrin Pilkey, director of the Program for the Study of Developed Shorelines (PSDS) in Durham, N.C. This was due in part to the nature of the storm itself and where it hit land, and in part to the regional geology, said Rob Thieler of PSDS. Despite the huge amounts of damage to buildings, there was virtually no evidence of coastal process destruction, he said.

  6. Beach rock from Goa Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.; Wagle, B.G.

    constituents of beach rock found along Goa coast is dealt with in detail. While discussing the various views on its origin, it is emphasized that the process of cementation is chiefly controlled by ground water evaporation, inorganic precipitation and optimum...

  7. West Coast Regional Office Permits

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Fisheries implemented a license limitation program for the trawl and fixed gear sectors of Pacific Coast commercial groundfish fishery on January 1, 1993. The...

  8. Geomorphology of the Goa Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Wagle, B.G.

    This paper is based on the observations and interpretations of aerial photographs (1;25, 000 and 1:15, 000) of the Goa Coast. Aerial photocharacters like zonal differences, texture, shape, size, form, pattern, vegetation, soil characteristics...

  9. 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.

  10. A Comprehensive evaluation of groundwater vulnerability to saltwater up-coning and sea water intrusion in a coastal aquifer (case study: Ghaemshahr-juybar aquifer)

    Science.gov (United States)

    Motevalli, Alireza; Moradi, Hamid Reza; Javadi, Saman

    2018-02-01

    Aquifer salinization has recently increased significantly due to human activity and has caused irreparable environmental and economic effects. In this research, a new method is proposed for modeling the vulnerability to salinity for the Ghaemshahr-juybar aquifer. Specifically, the GALDIT (Sea water intrusion) and TAWLBIC (Saltwater up-coning) indices were combined to produce a map of vulnerability (Comprehensive Salinity Index or CSI) to seawater intrusion of a region near the coast and saltwater up-coning away from the coast, respectively. Single parameter and removal layer sensitivity analysis were performed in order to identify the sensitive parameters and achieve optimal weights (through the single-parameter method) of contributing factors in all three methods. The three optimized methods produced were GALDIT-Opt, TAWLBIC-Opt and CSI-Opt. To assess the accuracy of the original maps and optimal ones, the Pearson correlation was used. Results indicated that the Pearson correlation of the optimized GALDIT, TAWLBIC and CSI model was better than GALDIT, TAWLBIC and CSI. The results show that the increase in correlation between EC (Electrical Conductivity), TDS (Total Dissolved Solids) and SAR (Sodium Adsorption Ratio) from the GALDIT model to the CSI-Opt model from values of 0.64, 0.56 and 0.68 has improved to values of 0.81, 0.88 and 0.91, respectively. The highest concentration of EC, with a value of 7050 μs/cm, is sampled in the areas of the east and northwest of the Ghaemshahr-juybar aquifer, which are classified in the CSI-Opt model as high and very high vulnerability levels. The highest concentration of TDS and SAR has been found in the east, northwest and northeast of the Ghaemshahr-juybar aquifer with a value of 4724 ppm for TDS and 14 mg/l for SAR that have been modeled in the CSI-Opt index as highly vulnerable areas. Eventually, CSI mapping can be used as an efficient tool in prioritizing in terms of the vulnerability to aquifer salinity, carrying out

  11. Understanding Kendal aquifer system: a baseline analysis for sustainable water management proposal

    Science.gov (United States)

    Lukman, A.; Aryanto, M. D.; Pramudito, A.; Andhika, A.; Irawan, D. E.

    2017-07-01

    North coast of Java has been grown as the center of economic activities and major connectivity hub for Sumatra and Bali. Sustainable water management must support such role. One of the basis is to understand the baseline of groundwater occurrences and potential. However the complex alluvium aquiver system has not been well-understood. A geoelectric measurements were performed to determine which rock layer has a good potential as groundwater aquifers in the northern coast of Kaliwungu Regency, Kendal District, Central Java province. Total of 10 vertical electrical sounding (VES) points has been performed, using a Schlumberger configuration with the current electrode spacing (AB/2) varies between 200 - 300 m and the potential difference electrode spacing (MN/2) varies between 0.5 to 20 m with depths target ranging between 150 - 200 m. Geoelectrical data processing is done using Ip2win software which generates resistivity value, thickness and depth of subsurface rock layers. Based on the correlation between resistivity value with regional geology, hydrogeology and local well data, we identify three aquifer layers. The first layer is silty clay with resistivity values vary between 0 - 10 ohm.m, then the second layer is tuffaceous claystone with resistivity value between 10 - 60 ohm.m. Both layers serve as impermeable layer. The third layer is sandy tuff with resistivity value between 60 - 100 ohm.m which serves as a confined aquifer layer located at 70 - 100 m below surface. Its thickness is vary between 70 to 110 m. The aquifer layer is a mixing of volcanic and alluvium sediment, which is a member of Damar Formation. The stratification of the aquifer system may change in short distance and depth. This natural setting prevent us to make a long continuous correlation between layers. Aquifer discharge is estimated between 5 - 71 L/s with the potential deep well locations lies in the west and southeast part of the study area. These hydrogeological settings should be used

  12. Simulated effects of projected pumping on the availability of freshwater in the Evangeline Aquifer in an area southwest of Corpus Christi, Texas

    Science.gov (United States)

    Groschen, George E.

    1985-01-01

    This study is an investigation of the continued availability of freshwater in the Evangeline aquifer along the Texas Gulf Coast and the potential for degradation of the water quality by salinewater intrusion. Recharge to the aquifer occurs by the infiltration of precipitation in the outcrop area and by cross-formational flow from deeper aquifers. The predevelopment recharge rate is about 6 to 8 cubic feet per second. The predevelopment flow is toward the coast. The flow is semiconfined in the outcrop area and confined underneath the Chicot aquifer in the eastern two-thirds of the study area. Discharge, under natural conditions, is upward into the Chicot aquifer and to the Nueces River or Gulf of Mexico. Intensive pumping by irrigators, industries, and municipalities over the last 80 years has created a cone of depression as deep as 219 feet below sea level under the city of Kingsville in Kleberg County. The total rate of pumpage in 1982 was 29.6 cubic feet per second.

  13. Development and Modelling of a High-Resolution Aquifer Analog in the Guarani Aquifer (Brazil)

    OpenAIRE

    Höyng, Dominik

    2014-01-01

    A comprehensive and detailed knowledge about the spatial distribution of physical and chemical properties in heterogeneous porous aquifers plays a decisive role for a realistic representation of governing parameters in mathematical models. Models allow the simulation, prediction and reproduction of subsurface flow and transport characteristics. This work explains the identification, characterization and effects of small-scale aquifer heterogeneities in the Guarani Aquifer System (GAS) in S...

  14. Honduras: Caribbean Coast

    Energy Technology Data Exchange (ETDEWEB)

    Harborne, Alastair R.; Afzal, Daniel C.; Andrews, Mark J. [Coral Cay Conservation, London (United Kingdom)

    2001-07-01

    The coast of Honduras, Central America, represents the southern end of the Mesoamerican Barrier Reef System, although its marine resources are less extensive and studied than nearby Belize and Mexico. However, the coastal zone contains mainland reef formations, mangroves, wetlands, seagrass beds and extensive fringing reefs around its offshore islands, and has a key role in the economy of the country. Like most tropical areas, this complex of benthic habitats experiences limited annual variation in climatic and oceanographic conditions but seasonal and occasional conditions, particularly coral bleaching and hurricanes, are important influences. The effects of stochastic factors on the country's coral reefs were clearly demonstrated during 1998 when Honduras experienced a major hurricane and bleaching event. Any natural or anthropogenic impacts on reef health will inevitably affect other countries in Latin America, and vice versa, since the marine resources are linked via currents and the functioning of the system transcends political boundaries. Much further work on, for example, movement of larvae and transfer of pollutants is required to delineate the full extent of these links. Anthropogenic impacts, largely driven by the increasing population and proportion of people living in coastal areas, are numerous and include key factors such as agricultural run-off, over-fishing, urban and industrial pollution (particularly sewage) and infrastructure development. Many of these threats act synergistically and, for example, poor watershed management via shifting cultivation, increases sedimentation and pesticide run-off onto coral reefs, which increases stress to corals already affected by decreasing water quality and coral bleaching. Threats from agriculture and fishing are particularly significant because of the size of both industries. The desire to generate urgently required revenue within Honduras has also led to increased tourism which provides an over

  15. Honduras: Caribbean Coast.

    Science.gov (United States)

    Harborne, A R; Afzal, D C; Andrews, M J

    2001-12-01

    The coast of Honduras, Central America, represents the southern end of the Mesoamerican Barrier Reef System, although its marine resources are less extensive and studied than nearby Belize and Mexico. However, the coastal zone contains mainland reef formations, mangroves, wetlands, seagrass beds and extensive fringing reefs around its offshore islands, and has a key role in the economy of the country. Like most tropical areas, this complex of benthic habitats experiences limited annual variation in climatic and oceanographic conditions but seasonal and occasional conditions, particularly coral bleaching and hurricanes, are important influences. The effects of stochastic factors on the country's coral reefs were clearly demonstrated during 1998 when Honduras experienced a major hurricane and bleaching event. Any natural or anthropogenic impacts on reef health will inevitably affect other countries in Latin America, and vice versa, since the marine resources are linked via currents and the functioning of the system transcends political boundaries. Much further work on, for example, movement of larvae and transfer of pollutants is required to delineate the full extent of these links. Anthropogenic impacts, largely driven by the increasing population and proportion of people living in coastal areas, are numerous and include key factors such as agricultural run-off, over-fishing, urban and industrial pollution (particularly sewage) and infrastructure development. Many of these threats act synergistically and, for example, poor watershed management via shifting cultivation, increases sedimentation and pesticide run-off onto coral reefs, which increases stress to corals already affected by decreasing water quality and coral bleaching. Threats from agriculture and fishing are particularly significant because of the size of both industries. The desire to generate urgently required revenue within Honduras has also led to increased tourism which provides an overarching stress

  16. Comparison of aquifer characteristics derived from local and regional aquifer tests.

    Science.gov (United States)

    Randolph, R.B.; Krause, R.E.; Maslia, M.L.

    1985-01-01

    A comparison of the aquifer parameter values obtained through the analysis of a local and a regional aquifer test involving the same area in southeast Georgia is made in order to evaluate the validity of extrapolating local aquifer-test results for use in large-scale flow simulations. Time-drawdown and time-recovery data were analyzed by using both graphical and least-squares fitting of the data to the Theis curve. Additionally, directional transmissivity, transmissivity tensor, and angle of anisotropy were computed for both tests. -from Authors Georgia drawdown transmissivity regional aquifer tests

  17. Steam Injection For Soil And Aquifer Remediation

    Science.gov (United States)

    The purpose of this Issue Paper is to provide to those involved in assessing remediation technologies for specific sites basic technical information on the use of steam injection for the remediation of soils and aquifers that are contaminated by...

  18. Hydrogeologic characterization of devonian aquifers in Uruguay

    International Nuclear Information System (INIS)

    Massa, E.

    1988-01-01

    This article carried out the assistance research project implementation in devonian sedimentary units as a potentials aquifers and their best use to school supplying and rural population in central area of Uruguay.

  19. Aquifer parameter identification and interpretation with different ...

    African Journals Online (AJOL)

    unfortunately, field data deviations from the model type curves are not considered in ... Such an extensive Study can only he done when there is a set of aquifer test data with main and .... 1990; 1995) methods are employed for qualitative.

  20. A General Solution for Groundwater Flow in Estuarine Leaky Aquifer System with Considering Aquifer Anisotropy

    Science.gov (United States)

    Chen, Po-Chia; Chuang, Mo-Hsiung; Tan, Yih-Chi

    2014-05-01

    In recent years the urban and industrial developments near the coastal area are rapid and therefore the associated population grows dramatically. More and more water demand for human activities, agriculture irrigation, and aquaculture relies on heavy pumping in coastal area. The decline of groundwater table may result in the problems of seawater intrusion and/or land subsidence. Since the 1950s, numerous studies focused on the effect of tidal fluctuation on the groundwater flow in the coastal area. Many studies concentrated on the developments of one-dimensional (1D) and two-dimensional (2D) analytical solutions describing the tide-induced head fluctuations. For example, Jacob (1950) derived an analytical solution of 1D groundwater flow in a confined aquifer with a boundary condition subject to sinusoidal oscillation. Jiao and Tang (1999) derived a 1D analytical solution of a leaky confined aquifer by considered a constant groundwater head in the overlying unconfined aquifer. Jeng et al. (2002) studied the tidal propagation in a coupled unconfined and confined costal aquifer system. Sun (1997) presented a 2D solution for groundwater response to tidal loading in an estuary. Tang and Jiao (2001) derived a 2D analytical solution in a leaky confined aquifer system near open tidal water. This study aims at developing a general analytical solution describing the head fluctuations in a 2D estuarine aquifer system consisted of an unconfined aquifer, a confined aquifer, and an aquitard between them. Both the confined and unconfined aquifers are considered to be anisotropic. The predicted head fluctuations from this solution will compare with the simulation results from the MODFLOW program. In addition, the solutions mentioned above will be shown to be special cases of the present solution. Some hypothetical cases regarding the head fluctuation in costal aquifers will be made to investigate the dynamic effects of water table fluctuation, hydrogeological conditions, and

  1. Sea-level rise impacts on seawater intrusion in coastal aquifers: Review and integration

    Science.gov (United States)

    Ketabchi, Hamed; Mahmoodzadeh, Davood; Ataie-Ashtiani, Behzad; Simmons, Craig T.

    2016-04-01

    Sea-level rise (SLR) influences groundwater hydraulics and in particular seawater intrusion (SWI) in many coastal aquifers. The quantification of the combined and relative impacts of influential factors on SWI has not previously been considered in coastal aquifers. In the present study, a systematic review of the available literature on this topic is first provided. Then, the potential remaining challenges are scrutinized. Open questions on the effects of more realistic complexities such as gradual SLR, parameter uncertainties, and the associated influences in decision-making models are issues requiring further investigation. We assess and quantify the seawater toe location under the impacts of SLR in combination with recharge rate variations, land-surface inundation (LSI) due to SLR, aquifer bed slope variation, and changing landward boundary conditions (LWBCs). This is the first study to include all of these factors in a single analysis framework. Both analytical and numerical models are used for these sensitivity assessments. It is demonstrated that (1) LSI caused by SLR has a significant incremental impact on the seawater toe location, especially in the flatter coasts and the flux-controlled (FC) LWBCs, however this impact is less than the reported orders of magnitude differences which were estimated using only analytical solutions; (2) LWBCs significantly influence the SLR impacts under almost all conditions considered in this study; (3) The main controlling factors of seawater toe location are the magnitudes of fresh groundwater discharge to sea and recharge rate. Regional freshwater flux entering from the landward boundary and the groundwater hydraulic gradient are the major contributors of fresh groundwater discharge to sea for both FC and head-controlled (HC) systems, respectively; (4) A larger response of the aquifer and larger seawater toe location changes are demonstrable for a larger ratio of the aquifer thickness to the aquifer length particularly in

  2. Guarani aquifer hydrogeological synthesis of the Guarani aquifer system. Edicion bilingue

    International Nuclear Information System (INIS)

    2009-01-01

    This work represents the synthesis of current knowledge of the Guarani Aquifer System, based on technical products made by different companies and consultants who participated in the framework of the Project for Environmental Protection and Sustainable Development of the Guarani Aquifer.

  3. Detection of coastal and submarine discharge on the Florida Gulf Coast with an airborne thermal-infrared mapping system

    Science.gov (United States)

    Raabe, Ellen; Stonehouse, David; Ebersol, Kristin; Holland, Kathryn; Robbins, Lisa

    2011-01-01

    Along the Gulf Coast of Florida north of Tampa Bay lies a region characterized by an open marsh coast, low topographic gradient, water-bearing limestone, and scattered springs. The Floridan aquifer system is at or near land surface in this region, discharging water at a consistent 70-72°F. The thermal contrast between ambient water and aquifer discharge during winter months can be distinguished using airborne thermal-infrared imagery. An airborne thermal-infrared mapping system was used to collect imagery along 126 miles of the Gulf Coast from Jefferson to Levy County, FL, in March 2009. The imagery depicts a large number of discharge locations and associated warm-water plumes in ponds, creeks, rivers, and nearshore waters. A thermal contrast of 6°F or more was set as a conservative threshold for identifying sites, statistically significant at the 99% confidence interval. Almost 900 such coastal and submarine-discharge locations were detected, averaging seven to nine per mile along this section of coast. This represents approximately one hundred times the number of previously known discharge sites in the same area. Several known coastal springs in Taylor and Levy Counties were positively identified with the imagery and were used to estimate regional discharge equivalent to one 1st-order spring, discharging 100 cubic feet per second or more, for every two miles of coastline. The number of identified discharge sites is a conservative estimate and may represent two-thirds of existing features due to low groundwater levels at time of overflight. The role of aquifer discharge in coastal and estuarine health is indisputable; however, mapping and quantifying discharge in a complex karst environment can be an elusive goal. The results of this effort illustrate the effectiveness of the instrument and underscore the influence of coastal springs along this stretch of the Florida coast.

  4. Aquifer response to earth tides

    International Nuclear Information System (INIS)

    Kanehiro, B.Y.; Narasimhan, T.N.

    1981-01-01

    The relation presented in the first part of this paper are applicable to packed-off wells and other situations where appreciable flow to the well does not exist. Comparisons of aquifer properties determined from the response to earth tides and from the more standard pumping tests for the two California fields are reasonably good. The case of an open well makes the problem more complicated, since there may be an appreciable amount of flow to the well. This flow to the well is seen as either a phase lag or as a difference in the ratio of the well signal to the tide for the semidiurnal and diurnal components of the tide. The latter is probably the better and more accurate indicator of flow to the well. Analyses of such situations, however, become involved and are probably best done as case-by-case studies. The numerical solutions show that treating the inverse problem through numerical modeling is at least feasible for any individual situation. It may be possible to simplify the inverse problem through the generation of type curves, but general type curves that are applicable to diverse situations are not likely to be practical. 7 figures

  5. 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

  6. 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.

  7. Contaminants in the coastal karst aquifer system along the Caribbean coast of the Yucatan Peninsula, Mexico

    International Nuclear Information System (INIS)

    Metcalfe, Chris D.; Beddows, Patricia A.; Bouchot, Gerardo Gold; Metcalfe, Tracy L.; Li Hongxia; Van Lavieren, Hanneke

    2011-01-01

    Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico may result in contamination of groundwater resources that eventually discharge into Caribbean coastal ecosystems. We deployed two types of passive sampling devices into groundwater flowing through cave systems below two communities to evaluate concentrations of contaminants and to indicate the possible sources. Pharmaceuticals and personal care products accumulated in the samplers could only have originated from domestic sewage. PAHs indicated contamination by runoff from highways and other impermeable surfaces and chlorophenoxy herbicides accumulated in samplers deployed near a golf course indicated that pesticide applications to turf are a source of contamination. Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health, thus damaging the tourism-based economy of the region. - Research highlights: → Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico is contaminating groundwater resources that discharge into Caribbean coastal ecosystems. → Passive sampling devices deployed in groundwater flowing through cave systems below two communities in the Riviera Maya accumulated: pharmaceuticals and personal care products originating from domestic sewage. → PAHs originating from runoff from highways and other impermeable surfaces; chlorophenoxy herbicides originating from pesticide applications to lawns and turf. → Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health in the region. - Contaminants accumulated in passive samplers deployed in flooded cave systems in the Yucatan Peninsula in Mexico indicate contamination by domestic sewage, runoff and applications of pesticides to turf.

  8. Contaminants in the coastal karst aquifer system along the Caribbean coast of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Metcalfe, Chris D; Beddows, Patricia A; Bouchot, Gerardo Gold; Metcalfe, Tracy L; Li, Hongxia; Van Lavieren, Hanneke

    2011-04-01

    Intensive land development as a result of the rapidly growing tourism industry in the "Riviera Maya" region of the Yucatan Peninsula, Mexico may result in contamination of groundwater resources that eventually discharge into Caribbean coastal ecosystems. We deployed two types of passive sampling devices into groundwater flowing through cave systems below two communities to evaluate concentrations of contaminants and to indicate the possible sources. Pharmaceuticals and personal care products accumulated in the samplers could only have originated from domestic sewage. PAHs indicated contamination by runoff from highways and other impermeable surfaces and chlorophenoxy herbicides accumulated in samplers deployed near a golf course indicated that pesticide applications to turf are a source of contamination. Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health, thus damaging the tourism-based economy of the region. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Contaminants in the coastal karst aquifer system along the Caribbean coast of the Yucatan Peninsula, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Metcalfe, Chris D., E-mail: cmetcalfe@trentu.ca [Worsfold Water Quality Centre, Trent University, Peterborough, ON, K9J 7B8 (Canada); Beddows, Patricia A. [Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL (United States); Bouchot, Gerardo Gold [Departemento de Recursos del Mar, CINVESTAV Unidad Merida, Yucatan (Mexico); Metcalfe, Tracy L.; Li Hongxia [Worsfold Water Quality Centre, Trent University, Peterborough, ON, K9J 7B8 (Canada); Van Lavieren, Hanneke [UN University Institute for Water, Environment and Health (UNU-INWEH), Hamilton, ON (Canada)

    2011-04-15

    Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico may result in contamination of groundwater resources that eventually discharge into Caribbean coastal ecosystems. We deployed two types of passive sampling devices into groundwater flowing through cave systems below two communities to evaluate concentrations of contaminants and to indicate the possible sources. Pharmaceuticals and personal care products accumulated in the samplers could only have originated from domestic sewage. PAHs indicated contamination by runoff from highways and other impermeable surfaces and chlorophenoxy herbicides accumulated in samplers deployed near a golf course indicated that pesticide applications to turf are a source of contamination. Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health, thus damaging the tourism-based economy of the region. - Research highlights: > Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico is contaminating groundwater resources that discharge into Caribbean coastal ecosystems. > Passive sampling devices deployed in groundwater flowing through cave systems below two communities in the Riviera Maya accumulated: pharmaceuticals and personal care products originating from domestic sewage. > PAHs originating from runoff from highways and other impermeable surfaces; chlorophenoxy herbicides originating from pesticide applications to lawns and turf. > Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health in the region. - Contaminants accumulated in passive samplers deployed in flooded cave systems in the Yucatan Peninsula in Mexico indicate contamination by domestic sewage, runoff and applications of pesticides to turf.

  10. Hydrological connectivity of perched aquifers and regional aquifers in semi-arid environments: a case study from Namibia

    Science.gov (United States)

    Hamutoko, J. T.; Wanke, H.

    2017-12-01

    Integrated isotopic and hydrological tracers along with standard hydrological data are used to understand complex dry land hydrological processes on different spatial and temporal scales. The objective of this study is to analyse the relationship between the perched aquifers and the regional aquifer using hydrochemical data and isotopic composition in the Cuvelai-Etosha Basin in Namibia. This relation between the aquifers will aid in understanding groundwater recharge processes and flow dynamics. Perched aquifers are discontinuous shallow aquifers with water level ranging from 0 to 30 meters below ground level. The regional aquifer occurs in semi-consolidated sandstone at depths between about 60 and 160 meters below ground level. Water samples were collected from both aquifers in 10 villages and were analysed for major ions and stable isotopes. The results show overlapping hydrochemistry and isotopic compositions of both aquifers in 8 villages which suggest the possibility of perched aquifer water infiltrating into the regional aquifer. In two villages the hydrochemistry and isotopic composition of the aquifers are totally different and this suggests that there is no interaction between this aquifers. Areas where perched aquifers are connected to regional aquifers maybe recharge zones. These finding have important implications for groundwater resource management.

  11. Transient well flow in vertically heterogeneous aquifers

    Science.gov (United States)

    Hemker, C. J.

    1999-11-01

    A solution for the general problem of computing well flow in vertically heterogeneous aquifers is found by an integration of both analytical and numerical techniques. The radial component of flow is treated analytically; the drawdown is a continuous function of the distance to the well. The finite-difference technique is used for the vertical flow component only. The aquifer is discretized in the vertical dimension and the heterogeneous aquifer is considered to be a layered (stratified) formation with a finite number of homogeneous sublayers, where each sublayer may have different properties. The transient part of the differential equation is solved with Stehfest's algorithm, a numerical inversion technique of the Laplace transform. The well is of constant discharge and penetrates one or more of the sublayers. The effect of wellbore storage on early drawdown data is taken into account. In this way drawdowns are found for a finite number of sublayers as a continuous function of radial distance to the well and of time since the pumping started. The model is verified by comparing results with published analytical and numerical solutions for well flow in homogeneous and heterogeneous, confined and unconfined aquifers. Instantaneous and delayed drainage of water from above the water table are considered, combined with the effects of partially penetrating and finite-diameter wells. The model is applied to demonstrate that the transient effects of wellbore storage in unconfined aquifers are less pronounced than previous numerical experiments suggest. Other applications of the presented solution technique are given for partially penetrating wells in heterogeneous formations, including a demonstration of the effect of decreasing specific storage values with depth in an otherwise homogeneous aquifer. The presented solution can be a powerful tool for the analysis of drawdown from pumping tests, because hydraulic properties of layered heterogeneous aquifer systems with

  12. Groundwater Quality and Quantity in a Coastal Aquifer Under High Human Pressure: Understand the Aquifer Functioning and the Social Perception of Water Use for a Better Water Management. Example of Recife (PE, Brazil)

    Science.gov (United States)

    Petelet-Giraud, E.; Cary, L.; Bertrand, G.; Alves, L. M.; Cary, P.; Giglio-Jacquemot, A.; Aquilina, L.; Hirata, R.; Montenegro, S.; Aurouet, A.; Franzen, M.; Chatton, E.

    2015-12-01

    The Recife Metropolitan Region is a typical "hot spot" illustrating the problems of southern countries on water issues inducing high pressures on water resources both on quantity and quality in the context of global social and environmental changes. This study is based on an interdisciplinary approach, coupling "hard" geosciences together with "soft" social sciences with the aim to study the human impact on coastal aquifers in a context of overexploitation to improve the existing water management tools. By revisiting the geological and hydrogeological conceptual models, field campaigns of groundwater and surface water sampling and analysis, and of interviews of different actors on the theme of water supply and management in Recife Metropolitan Region, the main results can be summarized as follows: (1) The recharge of the deep strategic confined aquifers is very limited resulting in water level decrease (up to -90m in 25y) due to overexploitation. (2) Groundwater residence time in these deep aquifers is over 10,000 years. (3) The natural upward flux of these confined aquifers is observed inland, but is reversed in the heavily populated areas along the coast leading to mixing with modern groundwater coming from the shallow aquifers. (4) Groundwater salinization is inherited from the Pleistocene marine transgression, only partly diluted by the recharge through the mangroves during the subsequent regression phase. Today, leakage from surficial aquifers induces local salinization. (5) Local climatic scenarios predict a reduction of rainfall volume of 20% together with an increase of sea level (18-59cm by 2100). (5) The Public authorities tend to deny the difficulties that people, especially those in precarious situation, are confronted with regarding water, especially in times of drought. The COQUEIRAL research project is financially supported by ANR (ANR-11-CEPL-012); FACEPE (APQ-0077-3.07/11); FAPESP (2011/50553-0

  13. 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.

  14. Submarine canyons off Madras Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.

    Submarine canyons off the coast of Madras, Tamil Nadu, India were studied during cruise of @iINS Kistna@@ as part of the IIOE programme They consist of hill-like projections and V-shaped valleys Their other features are also reported...

  15. 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.

  16. Application of a Density-Dependent Numerical Model (MODHMS) to Assess Salinity Intrusion in the Biscayne Aquifer, North Miami-Dade County, Florida

    Science.gov (United States)

    Guha, H.; Panday, S.

    2005-05-01

    Miami-Dade County is located at the Southeastern part of the State of Florida adjoining the Atlantic coast. The sole drinking water source is the Biscayne Aquifer, which is an unconfined freshwater aquifer, composed of marine limestone with intermediate sand lenses. The aquifer is highly conductive with hydraulic conductivity values ranging from 1,000 ft/day to over 100,000 ft/day in some areas. Saltwater intrusion from the coast is an immediate threat to the freshwater resources of the County. Therefore, a multilayer density-dependent transient groundwater model was developed to evaluate the saltwater intrusion characteristics of the system. The model was developed using MODHMS, a finite difference, fully coupled groundwater and surface water flow and transport model. The buoyancy term is included in the equation for unconfined flow and the flow and transport equations are coupled using an iterative scheme. The transport equation was solved using an adaptive implicit total variation diminishing (TVD) scheme and anisotropy of dispersivity was included for longitudinal, transverse, vertical transverse, and vertical longitudinal directions. The model eastern boundaries extended approximately 3.5 miles into the Atlantic Ocean while the western boundary extended approximately 27 miles inland from the coast. The northern and southern boundaries extend 6 miles into Broward County and up to the C-100 canal in Miami-Dade County respectively. Close to 2 million active nodes were simulated, with horizontal discretization of 500 feet. A total of nine different statistical analyses were conducted with observed and simulated hydraulic heads. The analysis indicates that the model simulated hydraulic heads matched closely with the observed heads across the model domain. In general, the model reasonably simulated the inland extent of saltwater intrusion within the aquifer, and matched relatively well with limited observed chloride data from monitoring wells along the coast

  17. Estimated rates of groundwater recharge to the Chicot, Evangeline and Jasper aquifers by using environmental tracers in Montgomery and adjacent counties, Texas, 2008 and 2011

    Science.gov (United States)

    Oden, Timothy D.; Truini, Margot

    2013-01-01

    Montgomery County is in the northern part of the Houston, Texas, metropolitan area, the fourth most populous metropolitan area in the United States. As populations have increased since the 1980s, groundwater has become an important resource for public-water supply and industry in the rapidly growing area of Montgomery County. Groundwater availability from the Gulf Coast aquifer system is a primary concern for water managers and community planners in Montgomery County and requires a better understanding of the rate of recharge to the system. The Gulf Coast aquifer system in Montgomery County consists of the Chicot, Evangeline, and Jasper aquifers, the Burkeville confining unit, and underlying Catahoula confining system. The individual sand and clay sequences of the aquifers composing the Gulf Coast aquifer system are not laterally or vertically continuous on a regional scale; however, on a local scale, individual sand and clay lenses can extend over several miles. The U.S. Geological Survey, in cooperation with the Lone Star Groundwater Conservation District, collected groundwater-quality samples from selected wells within or near Montgomery County in 2008 and analyzed these samples for concentrations of chlorofluorocarbons (CFCs), sulfur hexafluoride (SF6), tritium (3H), helium-3/tritium (3He/3H), helium-4 (4He), and dissolved gases (DG) that include argon, carbon dioxide, methane, nitrogen and oxygen. Groundwater ages, or apparent age, representing residence times since time of recharge, were determined by using the assumption of a piston-flow transport model. Most of the environmental tracer data indicated the groundwater was recharged prior to the 1950s, limiting the usefulness of CFCs, SF6, and 3H concentrations as tracers. In many cases, no tracer was usable at a well for the purpose of estimating an apparent age. Wells not usable for estimating an apparent age were resampled in 2011 and analyzed for concentrations of major ions and carbon-14 (14C). At six of

  18. 40 CFR 147.502 - Aquifer exemptions. [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. [Reserved] 147.502... (CONTINUED) STATE, TRIBAL, AND EPA-ADMINISTERED UNDERGROUND INJECTION CONTROL PROGRAMS Florida § 147.502 Aquifer exemptions. [Reserved] ...

  19. Simulation of seawater intrusion in coastal aquifers: Some typical ...

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    Seawater intrusion; coastal aquifers; density-dependent flow and ... The seawater intrusion mechanism in coastal aquifers generally causes the occurrence of ... (4) The dynamic viscosity of the fluid does not change with respect to salinity and.

  20. Upwelling along the east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, C.S.; Varadachari, V.V.R.

    the premonsoon and monsoon periods. Waters from deeper layers of the shelf appear to reach the surface causing considerable fall of surface temperature near the coast. The probable causes for these differences in upwelling along the coast are discussed...

  1. Zooplankton along the Tamil Nadu coast

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.; Saraswathy, M.

    Zooplankton abundance along two sectors at Cape Comorin and Tuticorin of Tamil Nadu Coast, southeast coast of India was studied. High biomass contributed by Ostracods, Salps, Chaetognaths etc., were observed along Tuticorin transect. In the Cape...

  2. Ground Water movement in crystalline rock aquifers

    International Nuclear Information System (INIS)

    Serejo, A.N.C.; Freire, C.; Siqueira, H.B. de; Frischkorn, H.; Torquato, J.R.F.; Santiago, M.M.F.; Barbosa, P.C.

    1984-01-01

    Ground water movement studies were performed in crystalline rock aquifers from the upper Acarau River hydrographic basin, state of Ceara, Brazil. The studies included carbon-14, 18 O/ 16 O and tritium measurements as well as chemical analysis. A total of 35 wells were surveyed during drought seasons. Carbon-14 values displayed little variation which implied that the water use was adequate despite of the slower recharge conditions. Fairly constant isotopic 18 O/ 16 O ratio values in the wells and their similarity with rainwater values indicated that the recharge is done exclusively by pluvial waters. A decreasing tendency within the tritium concentration values were interpreted as a periodic rainwater renewal for these aquifers. The chemical analysis demonstrated that there is in fact no correlation between salinity and the time the water remains in the aquifer itself. (D.J.M.) [pt

  3. CO2 point sources and subsurface storage capacities for CO2 in aquifers in Norway

    International Nuclear Information System (INIS)

    Boee, Reidulv; Magnus, Christian; Osmundsen, Per Terje; Rindstad, Bjoern Ivar

    2002-01-01

    The GESTCO project comprises a study of the distribution and coincidence of thermal CO 2 emission sources and location/quality of geological storage capacity in Europe. Four of the most promising types of geological storage are being studied. 1. Onshore/offshore saline aquifers with or without lateral seal. 2. Low entalpy geothermal reservoirs. 3. Deep methane-bearing coal beds and abandoned coal and salt mines. 4. Exhausted or near exhausted hydrocarbon structures. In this report we present an inventory of CO 2 point sources in Norway (1999) and the results of the work within Study Area C: Deep saline aquifers offshore/near shore Northern and Central Norway. Also offshore/near shore Southern Norway has been included while the Barents Sea is not described in any detail. The most detailed studies are on the Tilje and Aare Formations on the Troendelag Platform off Mid-Norway and on the Sognefjord, Fensfjord and Krossfjord Formations, southeast of the Troll Field off Western Norway. The Tilje Formation has been chosen as one of the cases to be studied in greater detail (numerical modelling) in the project. This report shows that offshore Norway, there are concentrations of large CO 2 point sources in the Haltenbanken, the Viking Graben/Tampen Spur area, the Southern Viking Graben and the central Trough, while onshore Norway there are concentrations of point sources in the Oslofjord/Porsgrund area, along the coast of western Norway and in the Troendelag. A number of aquifers with large theoretical CO 2 storage potential are pointed out in the North Sea, the Norwegian Sea and in the Southern Barents Sea. The storage capacity in the depth interval 0.8 - 4 km below sea level is estimated to be ca. 13 Gt (13000000000 tonnes) CO 2 in geological traps (outside hydrocarbon fields), while the storage capacity in aquifers not confined to traps is estimated to be at least 280 Gt CO 2 . (Author)

  4. Multiple-scale hydraulic characterization of a surficial clayey aquitard overlying a regional aquifer in Louisiana

    Science.gov (United States)

    Chapman, Steven W.; Cherry, John A.; Parker, Beth L.

    2018-03-01

    The vertical hydraulic conductivity (Kv) of a 30-m thick surficial clayey aquitard overlying a regional aquifer at an industrial site in the Mississippi River Valley in Louisiana was investigated via intensive hydraulic characterization using high resolution vertical hydraulic head profiles with temporal monitoring and laboratory tests. A study area was instrumented with a semi-circular array of piezometers at many depths in the aquitard at equal distance from a large capacity pumping well including replicate piezometers. Profiles showed negligible head differential to 20 m bgs, below which there was an abrupt change in vertical gradients over the lower 8-10 m of the aquitard. Hydraulic characteristics are strongly associated with depositional environment; the upper zone of minimal head differentials with depth and minimal variation over time correlates with Paleo-Mississippi River backswamp deposits, while the lower zone with large head differentials and slow but moderate head changes correlates with lacustrine deposits. The lower zone restricts groundwater flow between the surface and underlying regional aquifer, which is hydraulically connected to the Mississippi River. Lab tests on lacustrine samples show low Kv (8 × 10-11-4 × 10-9 m/s) bracketing field estimates (6 × 10-10 m/s) from 1-D model fits to piezometric data in response to large aquifer head changes. The slow response indicates absence of through-going open fractures in the lacustrine unit, consistent with geotechnical properties (high plasticity, normal consolidation), suggesting high integrity that protects the underlying aquifer from surficial contamination. The lack of vertical gradients in the overlying backswamp unit indicates abundant secondary permeability features (e.g. fractures, rootholes) consistent with depositional and weathering conditions. 2-D stylized transient flow simulations including both units supports this interpretation. Other published reports on surficial aquitards in the

  5. Unconsolidated Aquifers in Tompkins County, New York

    Science.gov (United States)

    Miller, Todd S.

    2000-01-01

    Unconsolidated aquifers consisting of saturated sand and gravel are capable of supplying large quantities of good-quality water to wells in Tompkins County, but little published geohydrologic inform ation on such aquifers is available. In 1986, the U.S.Geological Survey (USGS) began collecting geohydrologic information and well data to construct an aquifer map showing the extent of unconsolidated aquifers in Tompkins county. Data sources included (1) water-well drillers. logs; (2) highway and other construction test-boring logs; (3) well data gathered by the Tompkins County Department of Health, (4) test-well logs from geohydrologic consultants that conducted projects for site-specific studies, and (5) well data that had been collected during past investigations by the USGS and entered into the National Water Information System (NWIS) database. In 1999, the USGS, in cooperation with the Tompkins County Department of Planning, compiled these data to construct this map. More than 600 well records were entered into the NWIS database in 1999 to supplement the 350 well records already in the database; this provided a total of 950 well records. The data were digitized and imported into a geographic information system (GIS) coverage so that well locations could be plotted on a map, and well data could be tabulated in a digital data base through ARC/INFO software. Data on the surficial geology were used with geohydrologic data from well records and previous studies to delineate the extent of aquifers on this map. This map depicts (1) the extent of unconsolidated aquifers in Tompkins County, and (2) locations of wells whose records were entered into the USGS NWIS database and made into a GIS digital coverage. The hydrologic information presented here is generalized and is not intended for detailed site evaluations. Precise locations of geohydrologic-unit boundaries, and a description of the hydrologic conditions within the units, would require additional detailed, site

  6. 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.

  7. Using electrical resistivity tomography to assess the effectiveness of managed aquifer recharge in a salinized coastal aquifer.

    Science.gov (United States)

    García-Menéndez, Olga; Ballesteros, Bruno J; Renau-Pruñonosa, Arianna; Morell, Ignacio; Mochales, Tania; Ibarra, Pedro I; Rubio, Félix M

    2018-01-27

    Over 40 years, the detrital aquifer of the Plana de Castellón (Spanish Mediterranean coast) has been subjected to seawater intrusion because of long dry periods combined with intensive groundwater exploitation. Against this backdrop, a managed artificial recharge (MAR) scheme was implemented to improve the groundwater quality. The large difference between the electrical conductivity (EC) of the ambient groundwater (brackish water due to marine intrusion) and the recharge water (freshwater) meant that there was a strong contrast between the resistivities of the brackish water saturated zone and the freshwater saturated zone. Electrical resistivity tomography (ERT) can be used for surveying similar settings to evaluate the effectiveness of artificial recharge schemes. By integrating geophysical data with lithological information, EC logs from boreholes, and hydrochemical data, we can interpret electrical resistivity (ER) with groundwater EC values and so identify freshwater saturated zones. Using this approach, ERT images provided a high-resolution spatial characterization and an accurate picture of the shape and extent of the recharge plume of the MAR site. After 5 months of injection, a freshwater plume with an EC of 400-600 μS/cm had formed that extended 400 m in the W-E direction, 250 m in the N-S direction, and to a depth of 40 m below piezometric level. This study also provides correlations between ER values with different lithologies and groundwater EC values that can be used to support other studies.

  8. Spatial Reconnaissance : Technical Report ComCoast

    NARCIS (Netherlands)

    Verhagen, H.J.; Ahlhorn, F.

    2005-01-01

    ComCoast (Combined Functions in Coastal Defence Zones) is an INTERREG IIIB project funded by the EU. ComCoast aims to develop and demonstrate innovative solutions for flood protection in coastal areas. In ComCoast, five countries from the North Sea Region are involved: Belgium, Denmark, The

  9. Modelling contaminant transport in saturated aquifers

    International Nuclear Information System (INIS)

    Lakshminarayana, V.; Nayak, T.R.

    1990-01-01

    With the increase in population and industrialization the problem of pollution of groundwater has become critical. The present study deals with modelling of pollutant transport through saturated aquifers. Using this model it is possible to predict the concentration distribution, spatial as well as temporal, in the aquifer. The paper also deals with one of the methods of controlling the pollutant movement, namely by pumping wells. A simulation model is developed to determine the number, location and rate of pumping of a number of wells near the source of pollution so that the concentration is within acceptable limits at the point of interest. (Author) (18 refs., 14 figs., tab.)

  10. Hydraulic gradients in rock aquifers

    International Nuclear Information System (INIS)

    Dahlblom, P.

    1992-05-01

    This report deals with fractured rock as a host for deposits of hazardous waste. In this context the rock, with its fractures containing moving groundwater, is called the geological barrier. The desired properties of the geological barrier are low permeability to water, low hydraulic gradients and ability to retain matter dissolved in the water. The hydraulic gradient together with the permeability and the porosity determines the migration velocity. Mathematical modelling of the migration involves calculation of the water flow and the hydrodynamic dispersion of the contaminant. The porous medium approach can be used to calculate mean flow velocities and hydrodynamic dispersion of a large number of fractures are connected, which means that a large volume have to be considered. It is assumed that the porous medium approach can be applied, and a number of idealized examples are shown. It is assumed that the groundwater table is replenished by percolation at a constant rate. One-dimensional analytical calculations show that zero hydraulic gradients may exist at relatively large distance from the coast. Two-dimensional numerical calculations show that it may be possible to find areas with low hydraulic gradients and flow velocities within blocks surrounded by areas with high hydraulic conductivity. (au)

  11. Potential Offshore Submarine Groundwater in the Albufeira-Ribeira de Quarteira aquifer system (Algarve, Portugal)

    Science.gov (United States)

    Hugman, Rui; Stigter, Tibor; Monteiro, Jose Paulo

    2015-04-01

    The Albufeira-Ribeira de Quarteira aquifer system on the south coast of Portugal is an important source of groundwater for agriculture and tourism, as well as contributing to significant freshwater discharge along the coast in the form of inter- and sub-tidal springs and maintaining groundwater dependent ecosystems along the Quarteira stream. Submarine groundwater discharge (SGD) in the area was investigated within the scope of a multidisciplinary research project FREEZE (PTDC/MAR/102030/2008) which aimed to identify and characterize the effects of the hydrological/hydrogeological conditions on associated ecosystems. As well as near shore submarine springs, signs of SGD were found several kilometres from the shoreline during offshore CTD and geophysical surveys. On-land geophysical and offshore seismic surveys supplied data to update the 3D hydrogeological conceptual model of the aquifer system. Numerical models were applied to test the possibility of an offshore continuation of fresh groundwater over several kilometres under local conditions. Due to the high computational demand of variable density modelling, in an initial phase simplified 2D cross section models were used to test the conceptual model and reduce uncertainty in regards to model parameters. Results confirm the potential for SGD several kilometres from the coast within a range of acceptable values of hydraulic conductivity and recharge of the system. This represents the initial step in developing and calibrating a 3D regional scale model of the system, which aims to supply an estimate of the spatial distribution of SGD as well as serve as a decision support tool for the local water resources management agency.

  12. Comparison of groundwater flow in Southern California coastal aquifers

    Science.gov (United States)

    Hanson, Randall T.; Izbicki, John A.; Reichard, Eric G.; Edwards, Brian D.; Land, Michael; Martin, Peter

    2009-01-01

    Development of the coastal aquifer systems of Southern California has resulted in overdraft, changes in streamflow, seawater intrusion, land subsidence, increased vertical flow between aquifers, and a redirection of regional flow toward pumping centers. These water-management challenges can be more effectively addressed by incorporating new understanding of the geologic, hydrologic, and geochemical setting of these aquifers.

  13. Hydrogeology, water quality, and microbial assessment of a coastal alluvial aquifer in western Saudi Arabia: potential use of coastal wadi aquifers for desalination water supplies [Hydrogéologie, qualité de l’eau et évaluation microbienne d’un aquifère côtier alluvial dans l’Ouest de l’Arabie Saoudite: utilisation potentielle des aquifères côtiers des oueds pour l’alimentation en eau après désalinisation] [Hidrogeologia, qualidade da água e avaliação microbiológica de um aquífero costeiro no oeste da Arábia Saudita: uso potencial de aquíferos de wadi costeiros para dessalinização de águas destinadas a abastecimento] [Hidrogeología, calidad de agua y evaluación microbiana de un acuífero costero aluvial en Arabia Saudita occidental: uso potencial de acuíferos costeros uadis para la desalinización de los abastecimientos de agua

    KAUST Repository

    Missimer, Thomas M.

    2014-07-20

    Wadi alluvial aquifers located along coastal areas of the Middle East have been assumed to be suitable sources of feed water for seawater reverse osmosis facilities based on high productivity, connectedness to the sea for recharge, and the occurrence of seawater with chemistry similar to that in the adjacent Red Sea. An investigation of the intersection of Wadi Wasimi with the Red Sea in western Saudi Arabia has revealed that the associated predominantly unconfined alluvial aquifer divides into two sand-and-gravel aquifers at the coast, each with high productivity (transmissivity = 42,000 m2/day). This aquifer system becomes confined near the coast and contains hypersaline water. The hydrogeology of Wadi Wasimi shows that two of the assumptions are incorrect in that the aquifer is not well connected to the sea because of confinement by very low hydraulic conductivity terrigenous and marine muds and the aquifer contains hypersaline water as a result of a hydraulic connection to a coastal sabkha. A supplemental study shows that the aquifer system contains a diverse microbial community composed of predominantly of Proteobacteria with accompanying high percentages of Gammaproteobacteria, Alphaproteobacteria and Deltaproteobacteria.

  14. 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

  15. A longshore sediment transport estimation for the Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    Nayak, B.U.; Chandramohan, P.

    in Tamilnadu, and the Maharashtra Coast experience negligible annual net transport. The direction of annual net transport along the east coast is towards north and along the west coast towards south except at south Gujarat Coast...

  16. 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

    Heat was applied as a tracer for determining river–aquifer relations in the Motril-Salobreña aquifer (S Spain). The aquifer has typically been recharged by River Guadalfeo infiltration, nevertheless from 2005 a dam was constructed changing the traditional dynamic river flow and recharge events...

  17. Hydrological controls on transient aquifer storage in a karst watershed

    Science.gov (United States)

    Spellman, P.; Martin, J.; Gulley, J. D.

    2017-12-01

    While surface storage of floodwaters is well-known to attenuate flood peaks, transient storage of floodwaters in aquifers is a less recognized mechanism of flood peak attenuation. The hydraulic gradient from aquifer to river controls the magnitude of transient aquifer storage and is ultimately a function of aquifer hydraulic conductivity, and effective porosity. Because bedrock and granular aquifers tend to have lower hydraulic conductivities and porosities, their ability to attenuate flood peaks is generally small. In karst aquifers, however, extensive cave systems create high hydraulic conductivities and porosities that create low antecedent hydraulic gradients between aquifers and rivers. Cave springs can reverse flow during high discharges in rivers, temporarily storing floodwaters in the aquifer thus reducing the magnitude of flood discharge downstream. To date however, very few studies have quantified the magnitude or controls of transient aquifer storage in karst watersheds. We therefore investigate controls on transient aquifer storage by using 10 years of river and groundwater data from the Suwannee River Basin, which flows over the karstic upper Floridan aquifer in north-central Florida. We use multiple linear regression to compare the effects of three hydrological controls on the magnitude of transient aquifer storage: antecedent stage, recharge and slope of hydrograph rise. We show the dominant control on transient aquifer storage is antecedent stage, whereby lower stages result in greater magnitudes of transient aquifer storage. Our results suggest that measures of groundwater levels prior to an event can be useful in determining whether transient aquifer storage will occur and may provide a useful metric for improving predictions of flood magnitudes.

  18. 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.

  19. 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....

  20. Lithological and hydrological influences on ground-water composition in a heterogeneous carbonate-clay aquifer system

    Science.gov (United States)

    Kauffman, S.J.; Herman, J.S.; Jones, B.F.

    1998-01-01

    The influence of clay units on ground-water composition was investigated in a heterogeneous carbonate aquifer system of Miocene age in southwest Florida, known as the Intermediate aquifer system. Regionally, the ground water is recharged inland, flows laterally and to greater depths in the aquifer systems, and is discharged vertically upward at the saltwater interface along the coast. A depth profile of water composition was obtained by sampling ground water from discrete intervals within the permeable carbonate units during coring and by squeezing pore water from a core of the less-permeable clay layers. A normative salt analysis of solute compositions in the water indicated a marine origin for both types of water and an evolutionary pathway for the clay water that involves clay diagenesis. The chemical composition of the ground water in the carbonate bedrock is significantly different from that of the pore water in the clay layers. Dissolution of clays and opaline silica results in high silica concentrations relative to water in other parts of the Intermediate aquifer system. Water enriched in chloride relative to the overlying and underlying ground water recharges the aquifer inland where the confining clay layer is absent, and it dissolves carbonate and silicate minerals and reacts with clays along its flow path, eventually reaching this coastal site and resulting in the high chloride and silica concentrations observed in the middle part of the Intermediate aquifer system. Reaction-path modeling suggests that the recharging surficial water mixes with sulfate-rich water upwelling from the Upper Floridan aquifer, and carbonate mineral dissolution and precipitation, weathering and exchange reactions, clay mineral diagenesis, clay and silica dissolution, organic carbon oxidation, and iron and sulfate reduction result in the observed water compositions.A study was conducted to clarify the influence of clay units on ground-water composition in a heterogeneous

  1. Nutrient Removal during Stormwater Aquifer Storage and Recovery in an Anoxic Carbonate Aquifer.

    Science.gov (United States)

    Vanderzalm, Joanne L; Page, Declan W; Dillon, Peter J; Barry, Karen E; Gonzalez, Dennis

    2018-03-01

    Stormwater harvesting coupled to managed aquifer recharge (MAR) provides a means to use the often wasted stormwater resource while also providing protection of the natural and built environment. Aquifers can act as a treatment barrier within a multiple-barrier approach to harvest and use urban stormwater. However, it remains challenging to assess the treatment performance of a MAR scheme due to the heterogeneity of aquifers and MAR operations, which in turn influences water treatment processes. This study uses a probabilistic method to evaluate aquifer treatment performance based on the removal of total organic C (TOC), N, and P during MAR with urban stormwater in an anoxic carbonate aquifer. Total organic C, N, and P are represented as stochastic variables and described by probability density functions (PDFs) for the "injectant" and "recovery"; these injectant and recovery PDFs are used to derive a theoretical MAR removal efficiency PDF. Four long-term MAR sites targeting one of two tertiary carbonate aquifers (T1 and T2) were used to describe the nutrient removal efficiencies. Removal of TOC and total N (TN) was dominated by redox processes, with median removal of TOC between 50 and 60% at all sites and TN from 40 to 50% at three sites with no change at the fourth. Total P removal due to filtration and sorption accounted for median removal of 29 to 53%. Thus, the statistical method was able to characterize the capacity of the anoxic carbonate aquifer treatment barrier for nutrient removal, which highlights that aquifers can be an effective long-term natural treatment option for management of water quality, as well as storage of urban stormwater. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Risk assessment and management of an oil contaminated aquifer

    International Nuclear Information System (INIS)

    Braxein, A.; Daniels, H.; Rouve, G.; Rubin, H.

    1991-01-01

    This paper concerns the provision of the basic information needed for the decision making process regarding the remedial measures leading to reutilization of an oil contaminated aquifer. The study refers to the case history of jet fuel contamination of an aquifer comprising part of the coastal aquifer of Israel. Due to that contamination two major water supply wells were abandoned. This study examines the use of numerical simulations in order to restore the contamination history of the aquifer. Such simulations also provide quantitative information needed for the decision making process regarding the future management of the contaminated aquifer

  3. Remediation of a contaminated thin aquifer by horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Breh, W.; Suttheimer, J.; Hoetzl, H. [Univ. of Karlsruhe (Germany); Frank, K. [GEO-Service GmbH, Rheinmuenster (Germany)

    1997-12-31

    At an industrial site in Bruchsal (Germany) a huge trichloroethene contamination was found. After common remedial actions proved to be widely ineffective, new investigations led to a highly contaminated thin aquifer above the main aquifer. The investigation and the beginning of the remediation of the thin aquifer by two horizontal wells is described in this paper. Special attention was given to the dependence between precipitation and the flow direction in the thin aquifer and to hydraulic connections between the thin and the main aquifer. Also a short introduction into a new remedial technique by horizontal wells and first results of the test phase of the horizontal wells are given.

  4. Groundwater sustainability assessment in coastal aquifers

    Indian Academy of Sciences (India)

    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 ...

  5. 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

  6. Hydrochemical characterization of groundwater aquifer using ...

    African Journals Online (AJOL)

    Hydrochemical data analysis revealed four sources of solutes. The processes responsible for their enrichment include: chemical weathering, leaching of the overlying sediments, domestic activities, climatic condition and the flow pattern of the aquifer. The factors have contributed to the changes of the groundwater chemistry ...

  7. Transient well flow in vertically heterogeneous aquifers.

    NARCIS (Netherlands)

    Hemker, C.J.

    1999-01-01

    A solution for the general problem of computing well flow in vertically heterogeneous aquifers is found by an integration of both analytical and numerical techniques. The radial component of flow is treated analytically; the drawdown is a continuous function of the distance to the well. The

  8. Aquifer restoration: state of the art

    National Research Council Canada - National Science Library

    Knox, Robert C; Knox, R. C

    1986-01-01

    ... of chemicals or waste materials, improper underground injection of liquid wastes, and placement of septic tank systems in hydrologically and geologically unsuitable locations. Incidents of aquifer pollution from man's waste disposal activities have been discovered with increasing regularity. At the same time, demands for groundwater usage have been inc...

  9. Sedimentological analysis of a contaminated groundwater aquifer

    International Nuclear Information System (INIS)

    Towse, D.

    1991-01-01

    The use of sedimentological reservoir analysis techniques adapted from standard oilfield practice can improve the efficiency and reduce the costs of the evaluation of groundwater aquifers and the design of restoration programs. An evaluation/restoration program at a site in California drilled over 200 test wells in about 750 ac. All wells were logged lithologically and with wireline. The shallow aquifer is a complex braided alluvial floodplain deposit of Late Quaternary age. Analysis demonstrates depositional and erosional responses to periodic hinterland uplifts and to changing climatic conditions. Channel, overbank, lacustrine, and minor deltaic deposits can be recognized. The aquifer architecture has been interpreted to explain the movement of fuel and halogenated hydrocarbon solvents in the sediments and water. Routine engineering geology techniques and hydrologic tests were used to evaluate contamination and to design experimental restoration processes. As demonstrated here, sedimentological techniques show promise in reducing the costs and time required for this type of study. The abundant detailed data will be used in an attempt to develop a microcomputer-based expert system for rapid preliminary analyses of similar aquifers or reservoirs

  10. VULNERABILITY AND RISK OF CONTAMINATION KARSTIC AQUIFERS

    Directory of Open Access Journals (Sweden)

    Yameli Aguilar

    2013-08-01

    Full Text Available Karstic systems occupy nearly 20% of the surface of the earth and are inhabited by numerous human communities. Karstic aquifers are the most exposed to pollution from human activities. Pollution of karstic aquifers is a severe environmental problem worldwide.  In order to face the vulnerability of karstic aquifers to pollution, researchers have created a diversity of study approaches and models, each one having their own strengths and weaknesses depending on the discipline from which they were originated, thus requiring a thorough discussion within the required multidisciplinary character. The objective of this article was to analyze the theoretical and methodological approaches applied to the pollution of karstic aquifers. The European hydrogeological, land evaluation, hydropedological and a geographic approach were analyzed. The relevance of a geomorphological analysis as a cartographic basis for the analysis of vulnerability and risks were emphasized. From the analysis of models, approaches and methodologies discussed the following recommendation is made: to form an interdisciplinary work team, to elaborate a conceptual model according to the site and the working scale and to e, apply and validate the model.

  11. isotopic characteristics of aquifers in sinai

    International Nuclear Information System (INIS)

    Al-Gamal, S.A.

    2004-01-01

    the environmental isotopes data (expressed as δ 2 d and δ 18 O) of different aquifers in sinai were treated using correlation and regression techniques. whereas, rain water isotopic data were treated using empirical orthogonal functions (EOF) techniques. environmental isotopes for different aquifers expressed in terms of O-18 and H-2, were taken to represent the isotopic characteristics. regression equations using the highly correlated variables of δ 2 d and δ 18 O were constructed for each aquifer. the latitudinal variations (of rainwater in sinai and selected climatic stations east mediterranean ) versus rainwater isotopic compositions were analyzed using the normalized variables. it was found that the latitudinal variations of the rainwater isotopic compositions ( δ 2 D, δ 18 O), vapor pressure, and surface temperature occurred in parallel and decreased with latitude. in the east mediterranean, empirical linear relationship between altitude and δ 2 D has indicted that the rate of change of δ 2 D with height is comparable with the dry lapse rate in the atmosphere.The obtained regression equations of environmental isotopes data have impacted on different slopes and different constants expressing the non-homogeneity in the isotopic composition of rainwater recharging the aquifers of sinai , due to the presence of different air masses

  12. 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...

  13. 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.

  14. Composition and fluxes of submarine groundwater along the Caribbean coast of the Yucatan Peninsula

    Science.gov (United States)

    Null, Kimberly A.; Knee, Karen L.; Crook, Elizabeth D.; de Sieyes, Nicholas R.; Rebolledo-Vieyra, Mario; Hernández-Terrones, Laura; Paytan, Adina

    2014-04-01

    Submarine groundwater discharge (SGD) to the coastal environment along the eastern Yucatan Peninsula, Quintana Roo, Mexico was investigated using a combination of tracer mass balances and analytical solutions. Two distinct submarine groundwater sources including water from the unconfined surficial aquifer discharging at the beach face and water from a deeper aquifer discharging nearshore through submarine springs (ojos) were identified. The groundwater of nearshore ojos was saline and significantly enriched in short-lived radium isotopes (223Ra, 224Ra) relative to the unconfined aquifer beach face groundwater. We estimated SGD from ojos using 223Ra and used a salinity mass balance to estimate the freshwater discharge at the beach face. Analytical calculations were also used to estimate wave set-up and tidally driven saline seepage into the surf zone and were compared to the salinity-based freshwater discharge estimates. Results suggest that average SGD from ojos along the Yucatan Peninsula Caribbean coast is on the order of 308 m3 d-1 m-1 and varies between sampling regions. Higher discharge was observed in the southern regions (568 m3 d-1 m-1) compared to the north (48 m3 d-1 m-1). Discharge at the beach face was in the range of 3.3-8.5 m3 d-1 m-1 for freshwater and 2.7 m3 d-1 m-1 for saline water based on the salinity mass balance and wave- and tidally-driven discharge, respectively. Although discharge from the ojos was larger in volume than discharge from the unconfined aquifer at the beach face, dissolved inorganic nitrogen (DIN) was significantly higher in beach groundwater; thus, discharge of this unconfined beach aquifer groundwater contributed significantly to total DIN loading to the coast. DIN fluxes were up to 9.9 mol d-1 m-1 from ojos and 2.1 mol d-1 m-1 from beach discharge and varied regionally along the 500 km coastline sampled. These results demonstrate the importance of considering the beach zone as a significant nutrient source to coastal waters

  15. 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

  16. Effects of climate variability on saltwater intrusions in coastal aquifers in Southern Denmark

    Science.gov (United States)

    Meyer, Rena; Sonnenborg, Torben; Engesgaard, Peter; Høyer, Anne-Sophie; Jørgensen, Flemming; Hisnby, Klaus; Hansen, Birgitte; Jensen, Jørn Bo; Piotrowski, Jan A.

    2016-04-01

    As in many other regions of the world fresh water supply in Denmark is based on groundwater resources. Aquifers in the low-lying areas in the south-west of Jutland are particularly vulnerable to saltwater intrusions which are likely to intensify due to relative sea level rise. To understand the dynamics and development of this complex flow system, the initial hydrodynamic conditions imposed by the last Scandinavian Ice Sheet (SIS) must be taken into account. The whole region has undergone changes in climatic and hydraulic conditions within the last 15000 years that may show influence on the present flow conditions. It is likely that the groundwater-flow dynamics, driven by the postglacial hydraulic head drop and the relative sea level rise are not yet equilibrated. Enhanced by the potential future sea level rise due to climate change, contamination of fresh-water aquifers will continue. The 2800-km2 - large coast-to-coast study area located in the southern part of Jutland was partly overridden by the Weichselian ice sheet. Geophysical and geological mapping shows salt water intrusions up to 20 km inland from the present coast. Based on a geological voxel model spanning Miocene through Quaternary deposits a large-scale 3D numerical groundwater flow and salt water transport model has been developed. It includes density-driven flow and simulates the distribution of the current saltwater intrusions and their evolution during the last 15000 years. Particle tracking and direct age simulations are performed to identify recharge areas and constrain groundwater ages. The simulated ages are compared to ages derived from isotope analysis of groundwater samples both from Miocene and Quaternary aquifers. The origin of the groundwater is determined based on isotopic and chemical composition. Additionally, heavy noble gas analysis is carried out to estimate recharge temperatures and mechanisms at locations where groundwater recharge during the last glaciation is indicated. This

  17. San Pedro River Aquifer Binational Report

    Science.gov (United States)

    Callegary, James B.; Minjárez Sosa, Ismael; Tapia Villaseñor, Elia María; dos Santos, Placido; Monreal Saavedra, Rogelio; Grijalva Noriega, Franciso Javier; Huth, A. K.; Gray, Floyd; Scott, C. A.; Megdal, Sharon; Oroz Ramos, L. A.; Rangel Medina, Miguel; Leenhouts, James M.

    2016-01-01

    The United States and Mexico share waters in a number of hydrological basins and aquifers that cross the international boundary. Both countries recognize that, in a region of scarce water resources and expanding populations, a greater scientific understanding of these aquifer systems would be beneficial. In light of this, the Mexican and U.S. Principal Engineers of the International Boundary and Water Commission (IBWC) signed the “Joint Report of the Principal Engineers Regarding the Joint Cooperative Process United States-Mexico for the Transboundary Aquifer Assessment Program" on August 19, 2009 (IBWC-CILA, 2009). This IBWC “Joint Report” serves as the framework for U.S.-Mexico coordination and dialogue to implement transboundary aquifer studies. The document clarifies several details about the program such as background, roles, responsibilities, funding, relevance of the international water treaties, and the use of information collected or compiled as part of the program. In the document, it was agreed by the parties involved, which included the IBWC, the Mexican National Water Commission (CONAGUA), the U.S. Geological Survey (USGS), and the Universities of Arizona and Sonora, to study two priority binational aquifers, one in the San Pedro River basin and the other in the Santa Cruz River basin. This report focuses on the Binational San Pedro Basin (BSPB). Reasons for the focus on and interest in this aquifer include the fact that it is shared by the two countries, that the San Pedro River has an elevated ecological value because of the riparian ecosystem that it sustains, and that water resources are needed to sustain the river, existing communities, and continued development. This study describes the aquifer’s characteristics in its binational context; however, most of the scientific work has been undertaken for many years by each country without full knowledge of the conditions on the other side of the border. The general objective of this study is to

  18. Effects of Aquifer Development and Changes in Irrigation Practices on Ground-Water Availability in the Santa Isabel Area, Puerto Rico

    Science.gov (United States)

    Kuniansky, Eve L.; Gómez-Gómez, Fernando; Torres-Gonzalez, Sigfredo

    2003-01-01

    The alluvial aquifer in the area of Santa Isabel is located within the South Coastal Plain aquifer of Puerto Rico. Variations in precipitation, changes in irrigation practices, and increasing public-supply water demand have been the primary factors controlling water-level fluctuations within the aquifer. Until the late 1970s, much of the land in the study area was irrigated using inefficient furrow flooding methods that required large volumes of both surface and ground water. A gradual shift in irrigation practices from furrow systems to more efficient micro-drip irrigation systems occurred between the late 1970s and the late 1980s. Irrigation return flow from the furrow-irrigation systems was a major component of recharge to the aquifer. By the early 1990s, furrow-type systems had been replaced by the micro-drip irrigation systems. Water levels declined about 20 feet in the aquifer from 1985 until present (February 2003). The main effect of the changes in agricultural practices is the reduction in recharge to the aquifer and total irrigation withdrawals. Increases in ground-water withdrawals for public supply offset the reduction in ground-water withdrawals for irrigation such that the total estimated pumping rate in 2003 was only 8 percent less than in 1987. Micro-drip irrigation resulted in the loss of irrigation return flow to the aquifer. These changes resulted in lowering the water table below sea level over most of the Santa Isabel area. By 2002, lowering of the water table reversed the natural discharge along the coast and resulted in the inland movement of seawater, which may result in increased salinity of the aquifer, as had occurred in other parts of the South Coastal Plain. Management alternatives for the South Coastal Plain aquifer in the vicinity of Santa Isabel include limiting groundwater withdrawals or implementing artificial recharge measures. Another alternative for the prevention of saltwater intrusion is to inject freshwater or treated sewage

  19. Aquifer test to determine hydraulic properties of the Elm aquifer near Aberdeen, South Dakota

    Science.gov (United States)

    Schaap, Bryan D.

    2000-01-01

    The Elm aquifer, which consists of sandy and gravelly glacial-outwash deposits, is present in several counties in northeastern South Dakota. An aquifer test was conducted northeast of Aberdeen during the fall of 1999 to determine the hydraulic properties of the Elm aquifer in that area. An improved understanding of the properties of the aquifer will be useful in the possible development of the aquifer as a water resource. Historical water-level data indicate that the saturated thickness of the Elm aquifer can change considerably over time. From September 1977 through November 1985, water levels at three wells completed in the Elm aquifer near the aquifer test site varied by 5.1 ft, 9.50 ft, and 11.1 ft. From June 1982 through October 1999, water levels at five wells completed in the Elm aquifer near the aquifer test site varied by 8.7 ft, 11.4 ft, 13.2 ft, 13.8 ft, and 19.7 ft. The water levels during the fall of 1999 were among the highest on record, so the aquifer test was affected by portions of the aquifer being saturated that might not be saturated during drier times. The aquifer test was conducted using five existing wells that had been installed prior to this study. Well A, the pumped well, has an operating irrigation pump and is centrally located among the wells. Wells B, C, D, and E are about 70 ft, 1,390 ft, 2,200 ft, and 3,100 ft, respectively, in different directions from Well A. Using vented pressure transducers and programmable data loggers, water-level data were collected at the five wells prior to, during, and after the pumping, which started on November 19, 1999, and continued a little over 72 hours. Based on available drilling logs, the Elm aquifer near the test area was assumed to be unconfined. The Neuman (1974) method theoretical response curves that most closely match the observed water-level changes at Wells A and B were calculated using software (AQTESOLV for Windows Version 2.13-Professional) developed by Glenn M. Duffield of Hydro

  20. Potential for saltwater intrusion into the lower Tamiami aquifer near Bonita Springs, southwestern Florida

    Science.gov (United States)

    Shoemaker, W. Barclay; Edwards, K. Michelle

    2003-01-01

    A study was conducted to examine the potential for saltwater intrusion into the lower Tamiami aquifer beneath Bonita Springs in southwestern Florida. Field data were collected, and constant- and variable-density ground-water flow simulations were performed that: (1) spatially quantified modern and seasonal stresses, (2) identified potential mechanisms of saltwater intrusion, and (3) estimated the potential extent of saltwater intrusion for the area of concern. MODFLOW and the inverse modeling routine UCODE were used to spatially quantify modern and seasonal stresses by calibrating a constant-density ground-water flow model to field data collected in 1996. The model was calibrated by assuming hydraulic conductivity parameters were accurate and by estimating unmonitored ground-water pumpage and potential evapotranspiration with UCODE. Uncertainty in these estimated parameters was quantified with 95-percent confidence intervals. These confidence intervals indicate more uncertainty (or less reliability) in the estimates of unmonitored ground-water pumpage than estimates of pan-evaporation multipliers, because of the nature and distribution of observations used during calibration. Comparison of simulated water levels, streamflows, and net recharge with field data suggests the model is a good representation of field conditions. Potential mechanisms of saltwater intrusion into the lower Tamiami aquifer include: (1) lateral inland movement of the freshwater-saltwater interface from the southwestern coast of Florida; (2) upward leakage from deeper saline water-bearing zones through natural upwelling and upconing, both of which could occur as diffuse upward flow through semiconfining layers, conduit flow through karst features, or pipe flow through leaky artesian wells; (3) downward leakage of saltwater from surface-water channels; and (4) movement of unflushed pockets of relict seawater. Of the many potential mechanisms of saltwater intrusion, field data and variable

  1. Potentiometric Surface of the Upper Floridan Aquifer, West-Central Florida, May 2006

    Science.gov (United States)

    Ortiz, A.G.

    2007-01-01

    Introduction Hydrologic Conditions in West-Central Florida The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated by the middle confining unit. The middle confining unit and the Lower Floridan aquifer in west-central Florida generally contain highly mineralized water. The water-bearing units containing fresh water are herein referred to as the Upper Floridan aquifer. The Upper Floridan aquifer is the principal source of water in the Southwest Florida Water Management District and is used for major public supply, domestic use, irrigation, and brackish water desalination in coastal communities (Southwest Florida Water Management District, 2000). This map report shows the potentiometric surface of the Upper Floridan aquifer measured in May 2006. The potentiometric surface is an imaginary surface connecting points of equal altitude to which water will rise in tightly-cased wells that tap a confined aquifer system (Lohman, 1979). This map represents water-level conditions near the end of the dry season, when ground-water levels usually are at an annual low and withdrawals for agricultural use typically are high. The cumulative average rainfall of 50.23 inches for west-central Florida (from June 2005 through May 2006) was 2.82 inches below the historical cumulative average of 53.05 inches (Southwest Florida Water Management District, 2006). Historical cumulative averages are calculated from regional rainfall summary reports (1915 to most recent complete calendar year) and are updated monthly by the Southwest Florida Water Management District. This report, prepared by the U.S. Geological Survey in cooperation with the Southwest Florida Water Management District, is part of a semi-annual series of Upper Floridan aquifer potentiometric-surface map reports for west-central Florida. Potentiometric-surface maps have been prepared for January 1964, May 1969, May 1971, May 1973, May 1974, and for each May and September since 1975. Water

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

    Energy Technology Data Exchange (ETDEWEB)

    Musgrove, M., E-mail: mmusgrov@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Opsahl, S.P. [U.S. Geological Survey, 5563 DeZavala, Ste. 290, San Antonio, TX 78249 (United States); Mahler, B.J. [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Herrington, C. [City of Austin Watershed Protection Department, Austin, TX 78704 (United States); Sample, T.L. [U.S. Geological Survey, 19241 David Memorial Dr., Ste. 180, Conroe, TX 77385 (United States); Banta, J.R. [U.S. Geological Survey, 5563 DeZavala, Ste. 290, San Antonio, TX 78249 (United States)

    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 (NO{sub 3}{sup −}) loading to surface and groundwater. We investigate variability and sources of NO{sub 3}{sup −} 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 NO{sub 3}{sup −} stable isotopes (δ{sup 15}N and δ{sup 18}O). These data were augmented by historical data collected from 1937 to 2007. NO{sub 3}{sup −} concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO{sub 3}{sup −} 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 NO{sub 3}{sup −} 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 NO{sub 3}{sup −}. These results highlight the vulnerability of karst aquifers to NO{sub 3}{sup −} 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 NO{sub 3}{sup −} than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO 3 − ) loading to surface and groundwater. We investigate variability and sources of NO 3 − 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 NO 3 − stable isotopes (δ 15 N and δ 18 O). These data were augmented by historical data collected from 1937 to 2007. NO 3 − concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO 3 − 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 NO 3 − 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 NO 3 − . These results highlight the vulnerability of karst aquifers to NO 3 − 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 NO 3 − 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

  4. 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

    streamflows in the surficial aquifer, and changes in water levels in the confined aquifers primarily resulted from the increased withdrawals associated with increased irrigation pumping; this response was most apparent in the Delmarva Peninsula. These results suggest that water levels may not be susceptible to the effects of droughts in the confined aquifers of the NACP aquifer system not used for irrigation, unlike in the unconfined surficial aquifer.A second analysis also was conducted to assess the effects of sea-level rise on the groundwater system throughout the northern Atlantic Coastal Plain physiographic province because recent analyses of the relative rates of sea-level rise along the Atlantic coast indicate that the Mid-Atlantic region represents a hot spot with anomalously higher rates of sea-level rise than observed elsewhere in the United States. Groundwater levels rose from 0 to 3 ft in response to a 3-ft simulated change in sea-level position, with the largest response occurring along the shoreline and away from non-tidal streams. About 37 percent (or 10,000 square miles) of the area of the northern Atlantic Coastal Plain physiographic province may experience about a 0.5-ft or more increase in water levels with the 3-ft increase in sea-level position, whereas about 18 percent (almost 5,000 square miles) of land of the northern Atlantic Coastal Plain physiographic province may experience a 2-ft or more increase in water levels with the 3-ft increase in sea-level position.These increases in the water table are of particular concern in low-lying areas where the unsaturated (vadose) zone is already thin, thus creating concerns for groundwater inundation of subsurface infrastructure, such as basements, septic systems, and subway systems. This increase in the water table also will likely alter the distribution of groundwater discharge to surface-water bodies thus increasing groundwater flow to streams that would have otherwise discharged directly to coastal waters

  5. Aquifer thermal energy storage in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Iihola, H; Ala-Peijari, T; Seppaenen, H

    1988-01-01

    The rapid changes and crises in the field of energy during the 1970s and 1980s have forced us to examine the use of energy more critically and to look for new ideas. Seasonal aquifer thermal energy storage (T < 100/sup 0/C) on a large scale is one of the grey areas which have not yet been extensively explored. However, projects are currently underway in a dozen countries. In Finland there have been three demonstration projects from 1974 to 1987. International co-operation under the auspices of the International Energy Agency, Annex VI, 'Environmental and Chemical Aspects of Thermal Energy Storage in Aquifers and Research and Development of Water Treatment Methods' started in 1987. The research being undertaken in 8 countries includes several elements fundamental to hydrochemistry and biochemistry.

  6. Study of Aquifer Thermal Energy Storage

    Science.gov (United States)

    Okuyama, Masaaki; Umemiya, Hiromichi; Shibuya, Ikuko; Haga, Eiji

    Yamagata University 'Aquifer Thermal Energy Storage (ATES)' is the experimental system which has been running since 1982. From the results for along terms of experiments, we obtain many important knowledge. This paper presents the accomplishments for 16 years and the characteristics of thermal energy storage in thermal energy storage well. The conclusions show as follows. 1)In recent years, the thermal recovery factor of warm energy storage well becomes almost constant at about 60%. 2) The thermal recovery factor of cool energy storage well increases gradually and becomes at about 15%. 3) Since the ferric colloidal dam is formed in aquifer, thermal recovery factor increase year after year. 4) Back wash can remove clogging for ferric colloidal dam. 5) The apparent thermal diffusivity decrease gradually due to ferric colloidal dam.

  7. 75 FR 13081 - Fisheries off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program

    Science.gov (United States)

    2010-03-18

    ... West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program AGENCY: National... proposed Trawl Rationalization Program. We are interested in feedback concerning proposed regulations to... Pacific Fishery Management Council (Council) has been developing a trawl rationalization program that...

  8. Small protohistoric sites (fishing villages?) on the saurashtra coast, West Coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh

    During the maritime archaeological explorations a few sites of protohistoric in nature have been noticed along the saurashtra coast. the trial excavations of a few sites namely Bet Dwarka and Bhokhira on the western saurashtra coast yielded...

  9. Surf zone dynamics along the south Karnataka Coast between Bhatkal and Ullal, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; SanilKumar, V.; Nayak, B.U.; Raju, N.S.N.

    stronger in June, and relatively low and steady during the rest of the year. Coast between Padubidri and Ullal experienced relatively stronger longshore currents than the coast between Maravanthe and Malpe. Longshore sediment transport rate was relatively...

  10. Increasing freshwater recovery upon aquifer storage : A field and modelling study of dedicated aquifer storage and recovery configurations in brackish-saline aquifers

    NARCIS (Netherlands)

    Zuurbier, Koen

    2016-01-01

    The subsurface may provide opportunities for robust, effective, sustainable, and cost-efficient freshwater management solutions. For instance, via aquifer storage and recovery (ASR; Pyne, 2005): “the storage of water in a suitable aquifer through a well during times when water is available, and the

  11. Understanding Uranium Behavior in a Reduced Aquifer

    Science.gov (United States)

    Janot, N.; Lezama-Pacheco, J. S.; Williams, K. H.; Bernier-Latmani, R.; Long, P. E.; Davis, J. A.; Fox, P. M.; Yang, L.; Giammar, D.; Cerrato, J. M.; Bargar, J.

    2012-12-01

    Uranium contamination of groundwater is a concern at several US Department of Energy sites, such Old Rifle, CO. Uranium transport in the environment is mainly controlled by its oxidation state, since oxidized U(VI) is relatively mobile, whereas U(IV) is relatively insoluble. Bio-remediation of contaminated aquifers aims at immobilizing uranium in a reduced form. Previous laboratory and field studies have shown that adding electron donor (lactate, acetate, ethanol) to groundwater stimulates the activity of metal- and sulfate-reducing bacteria, which promotes U(VI) reduction in contaminated aquifers. However, obtaining information on chemical and physical forms of U, Fe and S species for sediments biostimulated in the field, as well as kinetic parameters such as U(VI) reduction rate, is challenging due to the low concentration of uranium in the aquifers (typically bio-remediation experiment at the Old Rifle site, CO, from early iron-reducing conditions to the transition to sulfate-reducing conditions. Several in-well chromatographic columns packed with sediment were deployed and were sampled at different days after the start of bio-reduction. X-ray absorption spectroscopy and X-ray microscopy were used to obtain information on Fe, S and U speciation and distribution. Chemical extractions of the reduced sediments have also been performed, to determine the rate of Fe(II) and U(IV) accumulation.

  12. Carbon-14 measurements in aquifers with methane

    International Nuclear Information System (INIS)

    Barker, J.F.; Fritz, P.; Brown, R.M.

    1979-01-01

    A survey of various groundwater systems indicates that methane is a common trace constituent and occasionally a major carbon species in groundwaters. Thermocatalytic methane had delta 13 Csub(CH 4 )>-45 per mille and microbially produced or biogenic methane had delta 13 Csub(CH 4 ) 13 C values for the inorganic carbon. Thermocatalytic methane had no apparent effect on the inorganic carbon. Because methanogenesis seriously affects the carbon isotope geochemistry of groundwaters, the correction of raw 14 C ages of affected groundwaters must consider these effects. Conceptual models are developed which adjust the 14 C activity of the groundwater for the effects of methanogenesis and for the dilution of carbon present during infiltration by simple dissolution of rock carbonate. These preliminary models are applied to groundwaters from the Alliston sand aquifer where methanogenesis has affected most samples. In this system, methanogenic bacteria using organic matter present in the aquifer matrix as substrate have added inorganic carbon to the groundwater which has initiated further carbonate rock dissolution. These processes have diluted the inorganic carbon 14 C activity. The adjusted groundwater ages can be explained in terms of the complex hydrogeology of this aquifer, but also indicate that these conceptual models must be more rigorously tested to evaluate their appropriateness. (author)

  13. Hydrology of the shallow aquifer and uppermost semiconfined aquifer near El Paso, Texas

    Science.gov (United States)

    White, D.E.; Baker, E.T.; Sperka, Roger

    1997-01-01

    The availability of fresh ground water in El Paso and adjacent areas that is needed to meet increased demand for water supply concerns local, State, and Federal agencies. The Hueco bolson is the principal aquifer in the El Paso area. Starting in the early 1900s and continuing to the 1950s, most of the municipal and industrial water supply in El Paso was pumped from the Hueco bolson aquifer from wells in and near the Rio Grande Valley and the international border. The Rio Grande is the principal surface-water feature in the El Paso area, and a major source of recharge to the shallow aquifer (Rio Grande alluvium) within the study area is leakage of flow from the Rio Grande.

  14. 77 FR 66577 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

    Science.gov (United States)

    2012-11-06

    ...-XC165 Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program... implemented as part of the trawl rationalization program. FOR FURTHER INFORMATION CONTACT: Jamie Goen, phone..., NMFS implemented a trawl rationalization program, a catch share program, for the Pacific coast...

  15. A Simplified Methodology For Risk Assessment of The Oolitic Limestone Aquifer, West of Alexandria Coastal Zone

    International Nuclear Information System (INIS)

    Sadek, M.A.; Hussein, R.A.

    2013-01-01

    Groundwater risk analysis helps to assess the effects of contaminants reach to specific position in groundwater system after introduction at some location above the uppermost aquifer. This provides a basis for initiating protective and mitigation measures for important groundwater resources. An attempt has been made in the present study to assess the risk of diffuse groundwater pollution at the north western coast of Alexandria against landfill waste disposal as well as agricultural pollutants leachates which are the main land use in the studied area. A simplified weighing/ rating approach have been functioned for this purpose, Slovene methodology, which is relevant for fissured carbonate aquifers that characterize the studied area. This method is based on an origin-pathway-target model, which applies for both resource and source protection. Conservative values for the intrinsic geological, hydrogeological, geo morphological and climatological parameters have been reviewed and determined for assessment of the source and resource vulnerability, hazards and risk (lithology, texture and structure of soil zone, lithology and thickness of the unsaturated zone and aquifer conditions, morphological features, slope and vegetation cover, average annual stormy days, travel time and karst network , the fertilizers and pesticide used for agriculture, the volume of unlined waste disposal site). The methodology applied in the present study emphasizes how the physical properties of the hydrological system can be integrated in an index that reflects the level of risk of a diffuse pollution to groundwater. This aligns with the prospective of site safety evaluation around risky installations such as a nuclear power plants or waste disposal facilities where assurance should be done that the risk to the public and environment is acceptably low. According to the functioned methodology, the fissured limestone under study is low vulnerable and highly protectable against surface diffuse

  16. 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.

  17. Electrical Resistivity Imaging of Seawater Intrusion into the Monterey Bay Aquifer System.

    Science.gov (United States)

    Pidlisecky, A; Moran, T; Hansen, B; Knight, R

    2016-03-01

    We use electrical resistivity tomography to obtain a 6.8-km electrical resistivity image to a depth of approximately 150 m.b.s.l. along the coast of Monterey Bay. The resulting image is used to determine the subsurface distribution of saltwater- and freshwater-saturated sediments and the geologic controls on fluid distributions in the region. Data acquisition took place over two field seasons in 2011 and 2012. To maximize our ability to image both vertical and horizontal variations in the subsurface, a combination of dipole-dipole, Wenner, Wenner-gamma, and gradient measurements were made, resulting in a large final dataset of approximately 139,000 data points. The resulting resistivity section extends to a depth of 150 m.b.s.l., and is used, in conjunction with the gamma logs from four coastal monitoring wells to identify four dominant lithologic units. From these data, we are able to infer the existence of a contiguous clay layer in the southern portion of our transect, which prevents downward migration of the saltwater observed in the upper 25 m of the subsurface to the underlying freshwater aquifer. The saltwater and brackish water in the northern portion of the transect introduce the potential for seawater intrusion into the hydraulically connected freshwater aquifer to the south, not just from the ocean, but also laterally from north to south. © 2015, National Ground Water Association.

  18. Design and Testing of Recharge Wells in a Coastal Aquifer: Summary of Field Scale Pilot Tests

    Directory of Open Access Journals (Sweden)

    Joseph Guttman

    2017-01-01

    Full Text Available Surplus water from seawater desalination plants along the Israeli Coast can be injected underground for seasonal storage. Two pilot projects were established to simulate the movement of air bubbles and changes in the well hydraulic parameters during pumping and recharging. The study showed that it is impossible to remove the smaller air bubbles (dissolved air that are created during the injection process, even when the injection pipe is fully saturated. The pumping tests showed that there were large differences in the well hydraulic parameters between the pumping and the recharge tests despite that they were conducted at the same well. Two mechanisms are responsible for the reduction in the aquifer coefficients during the recharge event. The first mechanism is the pressures that the injected water needs to overcome; the aquifer pressure and the pore water pressure it is supposed to replace at the time of the injection. The second mechanism is the pressure that the injected water needs to overcome the clogging process. It is expressed as the high water level inside the recharge well in comparison to the small rising of the water level in the observation wells. This research gives good insight into the injection mechanism through wells and is essential for any further development of injection facilities and for the operation and management protocols.

  19. Regionalization and Evaluation of Impacts of Climate Change on Mexican Coasts

    Science.gov (United States)

    Nava-Sanchez, E. H.; Murillo-Jimenez, J. M.; Godinez-Orta, L.; Morales-Perez, R. A.

    2009-04-01

    the Gulf de California, (IV) Pacific Southwest Coast, and (V) Chiapaneca Coastal Plain. On the Atlantic coast, regions are: (VI) Tamulipeca Coastal Plain, (VII) Veracruzana Volcanic Coast, (VIII) Tabasqueña Coastal Plain, (IX) Yucatan Platform, and (X) Caribean Coast. Secondly, the coastal hazards associated to a rising sea level and increasing strength of coastal processes due to climate change, were analyzed, and allowed us to determine, in order of importance, the following hazards: (a) marine flooding, by sea level rise per se and effect of storm surges; (b) beach erosion by waves, causing lose of beach width or the retreat of the whole beach system, and overwash of sand barriers; (c) fluvial flooding of coastal plains and deltaic areas; (d) salinization of estuaries and aquifers by saltwater intrusion. Finally, after overlying the characteristics of each Coastal Region and its exposition to the identified coastal hazards, we concluded that, Coastal Regions highly vulnerable to sea level rise are number V and VIII, since they show wide lowlands (up to 7 m above MSL), and have high populated areas affected by heavy rain, tropical cyclones and storm surges; regions with moderate vulnerability are number VI, IX and X, which contain lowlands (up to 7 m above MSL), populated areas, exhibit watershed with low sediment production, and are located on the tropical cyclone tracks; regions with moderately low vulnerability are number III and VII, which contain relatively narrow lowlands, important lagoon and deltaic systems, several rivers are affected by anthropogenic activities, and are moderately affected by storms and tropical cyclones; regions with low vulnerability and short coastlines exposed to sea level rise hazards are regions number I and IV, which contain narrow lagoon and deltaic systems; and finally, region II is of a very low vulnerability, with narrow and scarce areas exposed to sea level rise hazards. This project was part of a Research Program on Climate

  20. 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.

  1. Using of hydrochemical and environmental isotopes water data for study of the Karst aquifers in the coastal area (Syria)

    International Nuclear Information System (INIS)

    Kassem, A.

    2001-12-01

    The isotopes and hydrogeological study are very importunate for limited Karstic aquifer our object was the determination of the movement and charging of groundwater and the type of karstics aquifer.. For realization this object we have analyzed 45 samples covered the most important karstic resources of water at the coast basin. The analyses involved the determination of major dissolved constituents (Ca, Mg, Na, K, HCO 3 , CO 3 , SO 4 , Cl and NO 3 , this analysis have determined by the El Fijeh society water laboratory) and isotopes constituents 3 H, 2 H, 18 O, this analysis was determined by the isotopes laboratory of Jordan) for 45 samples (44 of ground water and 1 of sea water) With the interpretation of hydro-geo-chemical data of all samples by H.Schoeller and Piper diagrams together with the evaluation of some factors (dph, pCO 2 , Is Dol, Mg/Ca and B.I), which had been determined by excel, Hydrowin and Solutaq programs (Used for karstic studies) were able to determine the natural of the aquifer rocks, the mechanisms of moving and transiting, the storing time or the transport time between all supplied sources and drainage, and the presence of surface contamination. (author)

  2. Coastal Aquifer Contamination and Geochemical Processes Evaluation in Tugela Catchment, South Africa—Geochemical and Statistical Approaches

    Directory of Open Access Journals (Sweden)

    Badana Ntanganedzeni

    2018-05-01

    Full Text Available Assessment of groundwater quality, contamination sources and geochemical processes in the coastal aquifer of Tugela Catchment, South Africa were carried out by the geochemical and statistical approach using major ion chemistry of 36 groundwater samples. Results suggest that the spatial distribution pattern of EC, TDS, Na, Mg, Cl and SO4 are homogenous and elevated concentrations are observed in the wells in the coastal region and few wells near the Tugela River. Wells located far from the coast are enriched by Ca, HCO3 and CO3. Durov diagrams, Gibbs plots, ionic ratios, chloro alkaline indices (CAI1 and CAI2 and correlation analysis imply that groundwater chemistry in the coastal aquifer of Tugela Catchment is regulated by the ion exchange, mineral dissolution, saline sources, and wastewater infiltration from domestic sewage; septic tank leakage and irrigation return flow. Principle component analysis also ensured the role of saline and anthropogenic sources and carbonates dissolution on water chemistry. Spatial distributions of factor score also justify the above predictions. Groundwater suitability assessment indicates that around 80% and 90% of wells exceeded the drinking water standards recommended by the WHO and South African drinking water standards (SAWQG, respectively. Based on SAR, RSC, PI, and MH classifications, most of the wells are suitable for irrigation in the study region. USSL classification suggests that groundwater is suitable for coarse-textured soils and salt-tolerant crops. The study recommends that a proper management plan is required to protect this coastal aquifer efficiently.

  3. Using of hydrochemical and environmental isotopes water data for study of the Karst aquifers in the coastal area (Syria)

    International Nuclear Information System (INIS)

    Kassem, A.

    2002-01-01

    The isotopes and hydrogeological study are very importunate for limited Karstic aquifer our object was the determination of the movement and charging of groundwater and the type of karstics aquifer.. For realization this object we have analyzed 45 samples covered the most important karstic resources of water at the coast basin. The analyses involved the determination of major dissolved constituents (Ca, Mg, Na, K, HCO 3 , CO 3 , SO 4 , Cl and NO 3 , this analysis have determined by the El Fijeh society water laboratory) and isotopes constituents 3 H, 2 H, 18 O, this analysis was determined by the isotopes laboratory of Jordan) for 45 samples (44 of ground water and 1 of sea water) With the interpretation of hydro-geo-chemical data of all samples by H.Schoeller and Piper diagrams together with the evaluation of some factors (dph, pCO 2 , Is Dol, Mg/Ca and B.I), which had been determined by excel, Hydrowin and Solutaq programs (Used for karstic studies) were able to determine the natural of the aquifer rocks, the mechanisms of moving and transiting, the storing time or the transport time between all supplied sources and drainage, and the presence of surface contamination. (author)

  4. Natural History of Oregon Coast Mammals

    Science.gov (United States)

    Chris Maser; Bruce R. Mate; Jerry F. Franklin; C.T. Dyrness

    1981-01-01

    The book presents detailed information on the biology, habitats, and life histories of the 96 species of mammals of the Oregon coast. Soils, geology, and vegetation are described and related to wildlife habitats for the 65 terrestrial and 31 marine species. The book is not simply an identification guide to the Oregon coast mammals but is a dynamic portrayal of their...

  5. Restoration of Wadi Aquifers by Artificial Recharge with Treated Waste Water

    KAUST Repository

    Missimer, Thomas M.; Drewes, Jö rg E.; Amy, Gary L.; Maliva,, Robert G.; Keller, Stephanie

    2012-01-01

    , such as damage to sensitive nearshore marine environments and creation of high-salinity interior surface water areas. An investigation of the hydrogeology of wadi aquifers in Saudi Arabia revealed that these aquifers can be used to develop aquifer recharge

  6. Straddle-packer aquifer test analyses of the Snake River Plain aquifer at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Johnson, G.S.; Frederick, D.B.

    1997-01-01

    The State of Idaho INEL Oversight Program, with the University of Idaho, Idaho State University, Boise State University, and the Idaho Geologic Survey, used a straddle-packer system to investigate vertical variations in characteristics of the Snake River Plain aquifer at the Idaho National Engineering Laboratory in southeast Idaho. Sixteen single-well aquifer tests were conducted on.isolated intervals in three observation wells. Each of these wells has approximately 200 feet of open borehole below the water table, penetrating the E through G and I basalt flow groups and interbedded sediments of the Snake River Plain aquifer. The success of the aquifer tests was limited by the inability to induce measurable drawdown in several zones. Time-drawdown data from aquifer tests were matched to type curves for 8 of the 16 zones tested. A single aquifer test at the water table exhibited greater curvature than those at depth. The increased degree of curvature suggests an unconfined response and resulted in an estimate of specific yield of 0.03. Aquifer tests below the water table generally yielded time-drawdown graphs with a rapid initial response followed by constant drawdown throughout the duration of the tests; up to several hours in length. The rapid initial response implies that the aquifer responds as a confined system during brief pumping periods. The nearly constant drawdown suggests a secondary source of water, probably vertical flow from overlying and underlying aquifer layers. Three analytical models were applied for comparison to the conceptual model and to provide estimates of aquifer properties. This, Hantush-Jacob leaky aquifer, and the Moench double-porosity fractured rock models were fit to time-drawdown data. The leaky aquifer type curves of Hantush and Jacob generally provided the best match to observed drawdown. A specific capacity regression equation was also used to estimate hydraulic conductivity

  7. 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

    Well construction, hydraulic well test, ambient water-quality, and cycle test data were inventoried and compiled for 30 aquifer storage and recovery facilities constructed in the Floridan aquifer system in southern Florida. Most of the facilities are operated by local municipalities or counties in coastal areas, but five sites are currently being evaluated as part of the Comprehensive Everglades Restoration Plan. The relative performance of all sites with adequate cycle test data was determined, and compared with four hydrogeologic and design factors that may affect recovery efficiency. Testing or operational cycles include recharge, storage, and recovery periods that each last days or months. Cycle test data calculations were made including the potable water (chloride concentration of less than 250 milligrams per liter) recovery efficiency per cycle, total recovery efficiency per cycle, and cumulative potable water recovery efficiencies for all of the cycles at each site. The potable water recovery efficiency is the percentage of the total amount of potable water recharged for each cycle that is recovered; potable water recovery efficiency calculations (per cycle and cumulative) were the primary measures used to evaluate site performance in this study. Total recovery efficiency, which is the percent recovery at the end of each cycle, however, can be substantially higher and is the performance measure normally used in the operation of water-treatment plants. The Upper Floridan aquifer of the Floridan aquifer system currently is being used, or planned for use, at 29 of the aquifer storage and recovery sites. The Upper Floridan aquifer is continuous throughout southern Florida, and its overlying confinement is generally good; however, the aquifer contains brackish to saline ground water that can greatly affect freshwater storage and recovery due to dispersive mixing within the aquifer. The hydrogeology of the Upper Floridan varies in southern Florida; confinement

  8. COAST code conversion from Cyber to HP

    International Nuclear Information System (INIS)

    Lee, Hae Cho

    1996-04-01

    The transient thermal hydraulic behavior of reactor coolant system in a nuclear power plant following loss of coolant flow is analyzed by use of COAST digital computer code. COAST calculates individual loop flow rates and steam generator pressure drops is a function of time following coast-down of any number of reactor coolant pumps. This report firstly describes detailed work carried out for installation of COAST on HP 9000/700 series and code validation results after installation. Secondly, a series of work is also describes in relation to installation of COAST on Apollo DN10000 series as well as relevant code validation results. Attached is a report on software verification and validation results. 7 refs. (Author) .new

  9. 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.

  10. Hydrochemical zonation of the western part of Göksu Delta aquifer system, Southern Turkey

    Science.gov (United States)

    Dokuz, U. E.; Çelik, M.; Arslan, Ş.; Engin, H.

    2012-04-01

    In general, coastal areas are preferred places for human settlement, especially at places where infrastructure routes benefit from rivers, streets, or harbours. As a result, these areas usually suffer from rising population and endure increasingly high demand on natural resources like water. Göksu Delta, located in southern Turkey, is one of the important wetland areas of Turkey at the Mediterranean coast. It is divided into two parts by Göksu River. The western part of the delta, which is the subject matter of this study, hosts fertile agricultural fields, touristic places and a Special Environmental Protection Area. These properties of the region lead to a water-dependent ecosystem where groundwater has widely been used for agricultural and domestic purposes. When the exploitation of groundwater peaked in the middle of 1990s, the groundwater levels dropped and seawater intruded. General Directorate of State Hydraulic Works tried to stop seawater intrusion by building irrigation channels connected to Göksu River and banned drilling of new wells for groundwater exploitation, although it is hard to control the drilling of wells without official permit. Geological studies show that the delta is composed of terrestrial sediments including clay to coarse sand deposited during Quaternary. The heterogeneous sediments of Göksu Delta cause hydrogeological features of the aquifer systems to be heterogeneous and anisotropic. Hydrogeological investigations, therefore, indicate mainly two different aquifers, shallow and deep, separated by an aquitard. The shallow aquifer is under unconfined to confined conditions from north to south while the deep aquifer is under confined conditions. This study focuses on hydrogeochemical zonation in terms of hydrochemical processes that affect the Göksu Delta aquifer systems. For this purpose, hydrogeochemical and isotopic studies are conducted to understand the salinisation and softening processes of groundwater. The physicochemical

  11. WTAQ - A computer program for aquifer-test analysis of confined and unconfined aquifers

    Science.gov (United States)

    Barlow, P.M.; Moench, A.F.

    2004-01-01

    Computer program WTAQ was developed to implement a Laplace-transform analytical solution for axial-symmetric flow to a partially penetrating, finite-diameter well in a homogeneous and anisotropic unconfined (water-table) aquifer. The solution accounts for wellbore storage and skin effects at the pumped well, delayed response at an observation well, and delayed or instantaneous drainage from the unsaturated zone. For the particular case of zero drainage from the unsaturated zone, the solution simplifies to that of axial-symmetric flow in a confined aquifer. WTAQ calculates theoretical time-drawdown curves for the pumped well and observation wells and piezometers. The theoretical curves are used with measured time-drawdown data to estimate hydraulic parameters of confined or unconfined aquifers by graphical type-curve methods or by automatic parameter-estimation methods. Parameters that can be estimated are horizontal and vertical hydraulic conductivity, specific storage, and specific yield. A sample application illustrates use of WTAQ for estimating hydraulic parameters of a hypothetical, unconfined aquifer by type-curve methods. Copyright ASCE 2004.

  12. Marine fishery possibilities of the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Panikkar, N.K.

    Marine fishery activity of the west coast of India is discussed. Sea fish production from the west coast of India makes three fourths of total fish production from Indian coasts. Kerala accounts for the largest production of fish in India...

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

    Science.gov (United States)

    Musgrove, MaryLynn; Opsahl, Stephen P.; Mahler, Barbara J.; Herrington, Chris; Sample, Thomas; Banta, John

    2016-01-01

    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 (δ15N and δ18O). 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

  14. 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.

  15. The detection of boundaries in leaky aquifers

    International Nuclear Information System (INIS)

    Cook, A.J.

    1989-01-01

    Geological faults in sedimentary basins can affect the regional and local groundwater flow patterns by virtue of their enhanced permeability properties. Faults can be regarded as vertical flow boundaries and potentially important routes for radionuclide migration from a theoretical radioactive waste repository. This report investigates the hydraulic testing methods currently available which may be used to locate vertical hydraulic discontinuities (boundaries) within an aquifer. It aims to define the theoretical limitations to boundary detection by a single pumping test, to determine the optimum design of a pumping test for locating boundaries, and to define the practical limitations to boundary detection by a pumping test. (author)

  16. Denitrification in the karstic Floridan Aquifer

    Science.gov (United States)

    Fork, M.; Albertin, A. R.; Heffernan, J. B.; Katz, B. G.; Cohen, M. J.

    2010-12-01

    Nitrate concentrations in the karstic Floridan Aquifer have increased dramatically over the past 50 years, owing to agricultural intensification and urbanization. Due to low concentrations of organic matter and moderately oxic conditions in the Floridan Aquifer, groundwater denitrification has been assumed to be negligible. In this study, we evaluate that assumption using both existing and new data describing dissolved gases (Ne, N2, O2, Ar) and NO3- concentration and isotopic composition (δ18O- and δ15N-NO3) in the aquifer’s artesian springs. For new data, we collected samples from 33 spring vents representing a gradient of both DO and NO3- concentrations in northern Florida and used Membrane Inlet Mass Spectrometry (MIMS) to directly measure dissolved N2 and Ar. We modeled the physical processes (recharge temperature, dissolution of excess air) driving super-saturation of N2 gas using Ne and Ar where data describing Ne were available. Ar concentrations were correlated closely with recharge temperature, which ranged from 15.7 - 22.2°C, while Ne was closely correlated with excess air, which ranged from 1.05 to 2.66 mg L-1 and averaged 1.83 mg L-1. Estimates of physical mechanisms allowed calculation of expected N2 concentrations that were compared to observed N2 concentrations. Where Ne data were unavailable, we assumed excess air equal to the empirical average. Overall, observed N2 exceeded expectations based on physical processes in 33 of 47 cases; average excess N2 was 0.48 mg L-1 across all sites. In addition, excess N2 was negatively correlated with DO (r2 = 0.46); springs with low DO (Aquifer. Low DOC concentrations indicate that alternative electron donors may fuel nitrate reduction. Scaling to regional estimates of N2 production based on springs discharge and DO concentrations indicates that subsurface denitrification may account for some of the imbalance in springshed nutrient budgets. In addition, we conclude that use of δ15N-NO3- to diagnose

  17. 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.

  18. Digital model evaluation of the predevelopment flow system of the Tertiary limestone aquifer, Southeast Georgia, Northeast Florida, and South South Carolina

    Science.gov (United States)

    Krause, Richard E.

    1982-01-01

    A computer model using finite-difference techniques was used successfully to simulate the predevelopment flow regime within the multilayered Tertiary limestone aquifer system in Southeastern Georgia, Northeastern Florida, and Southern South Carolina as part of the U.S. Geological Survey 's Tertiary Limestone Regional Aquifer System analysis. The aquifer, of early Eocene to Miocene age, ranges from thin interbedded clastics and marl in the updip area to massive limestone and dolomite 1,500 feet thick in the downdip area. The aquifer is confined above by Miocene clay beds, and terminates at depth in low-permeability rocks or the saltwater interface. Model-simulated transmissivity of the upper permeable zone ranged from about 1 x 10 super 3 foot squared per day in the updip area and within parts of the Gulf Trough (a series of alinement basins filled by fine clastic in material) to about 1 x 10 super 6 foot squared per day in South Georgia, and area having large secondarily developed solution channels. The model results indicate that only about 540 cubic feet per second of water flowed through the predeveloped system, from the updip highland area of high altitude and in the areas north of Valdosta and southwest of Jacksonville, to discharge along streams in the updip area and diffuse upward leakage in the downdip area near the coast and offshore. (USGS)

  19. The usefulness of multi-well aquifer tests in heterogeneous aquifers

    International Nuclear Information System (INIS)

    Young, S.C.; Benton, D.J.; Herweijer, J.C.; Sims, P.

    1990-01-01

    Three large-scale (100 m) and seven small-scale (3-7 m) multi-well aquifer tests were conducted in a heterogeneous aquifer to determine the transmissivity distribution across a one-hectare test site. Two of the large-scale tests had constant but different rates of discharge; the remaining large-scale test had a discharge that was pulsed at regulated intervals. The small-scale tests were conducted at two well clusters 20 m apart. The program WELTEST was written to analyze the data. By using the methods of non-linear least squares regression analysis and Broyden's method to solve for non-linear extrema, WELTEST automatically determines the best values of transmissivity and the storage coefficient. The test results show that order of magnitude differences in the calculated transmissivities at a well location can be realized by varying the discharge rate at the pumping well, the duration of the aquifer test, and/or the location of the pumping well. The calculated storage coefficients for the tests cover a five-order magnitude range. The data show a definite trend for the storage coefficient to increase with the distance between the pumping and the observation wells. This trend is shown to be related to the orientation of high hydraulic conductivity zones between the pumping and the observation wells. A comparison among single-well aquifer tests, geological investigations and multi-well aquifer tests indicate that the multi-well tests are poorly suited for characterizing a transmissivity field. (Author) (11 refs., 14 figs.)

  20. Bioremediation of a diesel fuel contaminated aquifer: simulation studies in laboratory aquifer columns

    Science.gov (United States)

    Hess, A.; Höhener, P.; Hunkeler, D.; Zeyer, J.

    1996-08-01

    The in situ bioremediation of aquifers contaminated with petroleum hydrocarbons is commonly based on the infiltration of groundwater supplemented with oxidants (e.g., O 2, NO 3-) and nutrients (e.g., NH 4+, PO 43-). These additions stimulate the microbial activity in the aquifer and several field studies describing the resulting processes have been published. However, due to the heterogeneity of the subsurface and due to the limited number of observation wells usually available, these field data do not offer a sufficient spatial and temporal resolution. In this study, flow-through columns of 47-cm length equipped with 17 sampling ports were filled with homogeneously contaminated aquifer material from a diesel fuel contaminated in situ bioremediation site. The columns were operated over 96 days at 12°C with artificial groundwater supplemented with O 2, NO 3- and PO 43-. Concentration profiles of O 2, NO 3-, NO 2-, dissolved inorganic and organic carbon (DIC and DOC, respectively), protein, microbial cells and total residual hydrocarbons were measured. Within the first 12 cm, corresponding to a mean groundwater residence time of < 3.6 h, a steep O 2 decrease from 4.6 to < 0.3 mg l -1, denitrification, a production of DIC and DOC, high microbial cell numbers and a high removal of hydrocarbons were observed. Within a distance of 24 to 40.5 cm from the infiltration, O 2 was below 0.1 mg l -1 and a denitrifying activity was found. In the presence and in the absence of O 2, n-alkanes were preferentially degraded compared to branched alkanes. The results demonstrate that: (1) infiltration of aerobic groundwater into columns filled with aquifer material contaminated with hydrocarbons leads to a rapid depletion of O 2; (2) O 2 and NO 3- can serve as oxidants for the mineralization of hydrocarbons; and (3) the modelling of redox processes in aquifers has to consider denitrifying activity in presence of O 2.

  1. Aquifer recharging in South Carolina: radiocarbon in environmental hydrogeology

    International Nuclear Information System (INIS)

    Stone, P.A.; Knox, R.L.; Mathews, T.D.

    1985-01-01

    Radiocarbon activities of dissolved inorganic carbon (and tritium activities where infiltration rates are rapid and aquifers shallow) provide relatively unambiguous and inexpensive evidence for identification of significant recharge areas. Such evidence is for the actual occurrence of modern recharge in the aquifer and thus is less inferential than stratigraphic or potentiometric evidence. These underutilized isotopic techniques are neither arcane nor complex and have been more-or-less standardized by earlier researchers. In South Carolina, isotopic evidence has been used from both calcareous and siliceous sedimentary aquifers and fractured crystalline rock aquifers. The Tertiary limestone aquifer is shown not to be principally recharged in its subcrop area, unlike conditions assumed for many other sedimentary aquifers in southeastern United States, and instead receives considerable lateral recharge from interfingering updip Tertiary sand aquifers in the middle coastal plain. Induced recharging at Hilton Head Island is mixing ancient relict water and modern recharge water. Recharging to deeper portions of the Cretaceous Middendorf basal sand aquifer occurs at least as far coastward as the middle coastal plain, near sampling sites that stratigraphically appear to be confined. Pronounced mineralization of water in fractured rocks cannot be considered as evidence of ancient or relict ground water that is isolated from modern contaminants, some of these waters contain considerable radiocarbon and hydrogen-bomb tritium

  2. Hydraulic properties from pumping tests data of aquifers in Azare ...

    African Journals Online (AJOL)

    Pumping test data from twelve boreholes in Azare area were analysed to determine the hydraulic properties of the aquifers, and the availability of water to meet the conjugate demands of the increasing population. The values of the aquifer constants obtained from the Cooper-Jacob's non-equilibrium graphical method were ...

  3. Estimating aquifer transmissivity from geo-electrical sounding ...

    African Journals Online (AJOL)

    Aquifer resistivity range from 4.26 ohm-m to 755.3 ohm-m with maximum thickness of 52.25m. A maximum 55.52m depth- tobasement was obtained in the study area. Based on the model obtained, aquifer Transmissivity was calculated and was used to delineate the study area into prospective low and high groundwater ...

  4. Hydrologic and isotopic study of the Quito aquifer

    International Nuclear Information System (INIS)

    Villalba, Fabio; Benalcazar, Julio; Garcia, Marco; Altamirano, Cesar; Altamirano, Homero; Sarasti, Santiago; Mancero, Maria; Leiva, Eduardo; Pino, Jose; Alulema, Rafael; Cedeno, Alberto; Burbano, Napoleon; Paquel, Efren; Becerra, Simon; Andrade, Graciela

    2000-10-01

    The dynamics of the Quito basin and surrounding area aquifers were determined through the use of stable and radioactive isotopes, and the monitoring of the freatic levels and of the bacteriological and physico-chemical quality of the water. A conceptual hydrodynamic model of the Quito aquifer was also proposed in order to establish in the future a sustainable management system

  5. Determining shallow aquifer vulnerability by the DRASTIC model ...

    Indian Academy of Sciences (India)

    Shallow aquifer vulnerability has been assessed using GIS-based DRASTIC model by incorporating the major geological and hydrogeological factors that affect and control the groundwater contamination in a granitic terrain. It provides a relative indication of aquifer vulnerability to the contamination. Further, it has been ...

  6. Investigating the salinization and freshening processes of coastal groundwater resources in Urmia aquifer, NW Iran.

    Science.gov (United States)

    Amiri, Vahab; Nakhaei, Mohammad; Lak, Razyeh; Kholghi, Majid

    2016-04-01

    This paper presents the results of an assessment about interaction between Urmia Lake (UL) and coastal groundwater in the Urmia aquifer (UA). This aquifer is the most significant contributor to the freshwater supply of the coastal areas. The use of hydrochemical facies can be very useful to identify the saltwater encroachment or freshening phases in the coastal aquifers. In this study, the analysis of salinization/freshening processes was carried out through the saturation index (SI), ionic deltas (Δ), binary diagrams, and hydrochemical facies evolution (HFE) diagram. Based on the Gibbs plot, the behavior of the major ions showed that the changes in the chemical composition of the groundwater are mainly controlled by the water-soil/rock interaction zone and few samples are relatively controlled by evaporation. A possible explanation for this phenomenon is that the deposited chloride and sulfate particles can form the minor salinity source in some coastal areas when washed down by precipitation. The SI calculations showed that all groundwater samples, collected in these periods, show negative saturation indices, which indicate undersaturation with respect to anhydrite, gypsum, and halite. In addition, except in a few cases, all other samples showed the undersaturation with respect to the carbonate minerals such as aragonite, calcite, and dolomite. Therefore, these minerals are susceptible to dissolution. In the dry season, the SI calculations showed more positive values with respect to dolomite, especially in the northern part of UA, which indicated a higher potential for precipitation and deposition of dolomite. The percentage of saltwater in the groundwater samples of Urmia plain was very low, ranging between 0.001 and 0.79 % in the wet season and 0.0004 and 0.81 % in the dry season. The results of HFE diagram, which was taken to find whether the aquifer was in the saltwater encroachment phase or in the freshening phase, indicated that except for a few wells

  7. 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

  8. Simple method for quick estimation of aquifer hydrogeological parameters

    Science.gov (United States)

    Ma, C.; Li, Y. Y.

    2017-08-01

    Development of simple and accurate methods to determine the aquifer hydrogeological parameters was of importance for groundwater resources assessment and management. Aiming at the present issue of estimating aquifer parameters based on some data of the unsteady pumping test, a fitting function of Theis well function was proposed using fitting optimization method and then a unitary linear regression equation was established. The aquifer parameters could be obtained by solving coefficients of the regression equation. The application of the proposed method was illustrated, using two published data sets. By the error statistics and analysis on the pumping drawdown, it showed that the method proposed in this paper yielded quick and accurate estimates of the aquifer parameters. The proposed method could reliably identify the aquifer parameters from long distance observed drawdowns and early drawdowns. It was hoped that the proposed method in this paper would be helpful for practicing hydrogeologists and hydrologists.

  9. Hydrogeology of the Umm Er Radhuma Aquifer (Arabian peninsula)

    Science.gov (United States)

    Dirks, Heiko; Al Ajmi, Hussain; Kienast, Peter; Rausch, Randolf

    2018-03-01

    The aim of this article is to enhance the understanding of the Umm Er Radhuma aquifer's genesis, and its hydraulic and hydrochemical development over time. This is a prerequisite for wise use of the fossil groundwater resources contained within. The Umm Er Radhuma is a karstified limestone aquifer, extending over 1.6 Mio. km2 in the eastern part of the Arabian Peninsula. Both epigene and hypogene karstification contributed to the genesis of what is today the most prolific aquifer in the region. Besides man-made abstractions, even the natural outflows are higher than the small recharge (natural storage depletion). The Umm Er Radhuma shows that large aquifers in arid regions are never in "steady state" (where inflows equal outflows), considering Quaternary climate history. The aquifer's adaption to climate changes (precipitation, sea level) can be traced even after thousands of years, and is slower than the climate changes themselves.

  10. Hydraulic barrier against seawater intrusion in the main aquifer of Delta del Llobregat; Barrera hidraulica contra la intrusion marina en el acuifero principal del Delta del Llobregat

    Energy Technology Data Exchange (ETDEWEB)

    Ortuno Gobern, F.; Ninerola Pla, J. M.; Fraile, J.; Juarez, I.; Molinero Huguet, J.; Arcos, D.; Pitarch, J. L.

    2009-07-01

    The main aquifer of Delta del Llobregat (Barcelona, Spain) is affected by seawater intrusion from 1970. For stopping its advance, the Catalan Water Agency is carrying out the construction of a positive hydraulic barrier through the injection of water in 14 wells. This is the first project of these characteristic that it is carried out in Spain and pioneer in Europe. The barrier elevates the groundwater level of the aquifer near the coast and avoids that the seawater penetrates inland, using reclaimed water of Baix Llobregat WWTP with several treatments. The first phase brings already more than 2 years of functioning, with highly positive results since a substantial improvement of the quality of the groundwater has been observed. The second phase is at present under construction. (Author)

  11. Geomorphic Controls on Aquifer Geometry in Northwestern India

    Science.gov (United States)

    van Dijk, W. M.; Densmore, A. L.; Sinha, R.; Gupta, S.; Mason, P. J.; Singh, A.; Joshi, S. K.; Nayak, N.; Kumar, M.; Shekhar, S.

    2014-12-01

    The Indo-Gangetic foreland basin suffers from one of the highest rates of groundwater extraction in the world, especially in the Indian states of Punjab, Haryana and Rajasthan. To understand the effects of this extraction on ground water levels, we must first understand the geometry and sedimentary architecture of the aquifer system, which in turn depend upon its geomorphic setting. We use satellite images and digital elevation models to map the geomorphology of the Sutlej and Yamuna river systems, while aquifer geometry is assessed using ~250 wells that extend to ~300 m depth in Punjab and Haryana. The Sutlej and Yamuna rivers have deposited large sedimentary fans at their outlets. Elongate downslope ridges on the fan surfaces form distributary networks that radiate from the Sutlej and Yamuna fan apices, and we interpret these ridges as paleochannel deposits associated with discrete fan lobes. Paleochannels picked out by soil moisture variations illustrate a complex late Quaternary history of channel avulsion and incision, probably associated with variations in monsoon intensity. Aquifer bodies on the Sutlej and Yamuna fans have a median thickness of 7 and 6 m, respectively, and follow a heavy-tailed distribution, probably because of stacked sand bodies. The percentage of aquifer material in individual lithologs decreases downstream, although the exponent on the thickness distribution remains the same, indicating that aquifer bodies decrease in number down fan but do not thin appreciably. Critically, the interfan area between the Sutlej and Yamuna fans has thinner aquifers and a lower proportion of aquifer material, despite its proximal location. Our data show that the Sutlej and Yamuna fan systems form the major aquifer systems in this area, and that their geomorphic setting therefore provides a first-order control on aquifer distribution and geometry. The large spatial heterogeneity of the system must be considered in any future aquifer management scheme.

  12. Modeling of CO2 storage in aquifers

    International Nuclear Information System (INIS)

    Savioli, Gabriela B; Santos, Juan E

    2011-01-01

    Storage of CO 2 in geological formations is a means of mitigating the greenhouse effect. Saline aquifers are a good alternative as storage sites due to their large volume and their common occurrence in nature. The first commercial CO 2 injection project is that of the Sleipner field in the Utsira Sand aquifer (North Sea). Nevertheless, very little was known about the effectiveness of CO 2 sequestration over very long periods of time. In this way, numerical modeling of CO 2 injection and seismic monitoring is an important tool to understand the behavior of CO 2 after injection and to make long term predictions in order to prevent CO 2 leaks from the storage into the atmosphere. The description of CO 2 injection into subsurface formations requires an accurate fluid-flow model. To simulate the simultaneous flow of brine and CO 2 we apply the Black-Oil formulation for two phase flow in porous media, which uses the PVT data as a simplified thermodynamic model. Seismic monitoring is modeled using Biot's equations of motion describing wave propagation in fluid-saturated poroviscoelastic solids. Numerical examples of CO 2 injection and time-lapse seismics using data of the Utsira formation show the capability of this methodology to monitor the migration and dispersal of CO 2 after injection.

  13. 14C measurements in aquifers with methane

    International Nuclear Information System (INIS)

    Barker, J.F.; Fritz, P.; Brown, R.M.

    1978-01-01

    A survey of various groundwater systems indicates that methane is a common trace constituent and occasionally a major carbon species in groundwaters. Thermocatalytic methane had delta 13 CCH 4 > -45% 0 and microbially-produced or biogenic methane had delta 13 CCH 4 0 . Groundwaters containing significant biogenic methane had abnormally heavy delta 13 C values for the inorganic carbon. Thermocatalytic methane had no apparent effect on the inorganic carbon. Because methanogenesis seriously affects the carbon isotope geochemistry of groundwaters, the correction of raw 14 C ages of affected groundwaters must consider these effects. Conceptual models are developed which adjust the 14 C activity of the groundwater for the effects of methanogenesis and for the dilution of carbon present during infiltration by simple dissolution of rock carbonate. These preliminary models are applied to groundwaters from the Alliston sand aquifer where methanogenesis has affected most samples. In this system, methanogenic bacteria using organic matter present in the aquifer matrix as substrate, have added inorganic carbon to the groundwater which has initiated further carbonate rock dissolution. These processes have diluted the inorganic carbon 14 C activity. (orig.) [de

  14. Marine conservation strategies for Maharashtra Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Dhargalkar, V.K.

    , Wildlife Sanctuaries, Marine Parks and Protected Areas. Detailed studies of 37 sites along the Maharashtra Coast, for their marine biota and also the ecological conditions, were taken up. Out of these, seven most luxuriant areas in marine biodiversity have...

  15. West Coast Rockfish Conservation Areas, 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data delineate Rockfish Conservation Areas (RCA) off the West Coast of the United States for 2015. There are three types of areas closures depicted in this...

  16. Eighteenth annual West Coast theoretical chemistry conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    Abstracts are presented from the eighteenth annual west coast theoretical chemistry conference. Topics include molecular simulations; quasiclassical simulations of reactions; photodissociation reactions; molecular dynamics;interface studies; electronic structure; and semiclassical methods of reactive systems.

  17. Pacific Coast Groundfish Individual Fishing Quota Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On January 11, 2011, NOAA Fisheries implemented a new fishery management system for the West Coast Groundfish Trawl Catch Share Program as specified in the...

  18. U.S. Coast Guard (USCG) Districts

    Data.gov (United States)

    Department of Homeland Security — This layer is a polygonal dataset that represents land and maritime boundaries for each representative United States Coast Guard district, which includes district 1,...

  19. Great Lakes CoastWatch Node

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CoastWatch is a nationwide National Oceanic and Atmospheric Administration (NOAA) program within which the Great Lakes Environmental Research Laboratory (GLERL)...

  20. CoastWatch Regions in HDF Format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The mapped data derived from AVHRR is divided into files for CoastWatch regions of interest. Each file contains multiple data variables stored using the HDF-4...

  1. Human interreference along the coast of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.

    , the promotion of tourism, increase in population and construction activities have created a heavy demand for resources resulting in congestion on coasts, increase in density of constructions and pressures on infrastructure. Large scale conversions of dune belts...

  2. Distribution of seagrasses along the Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    Jagtap, T.G.

    the Tamil Nadu Coast. Seagrasses were observed from intertidal to subtidal regions down to 8 m depth. Thalassia hemprichii (Ehrenberg) Aschers. and Cymodocea serrulata (R. Brown) Aschers. and Magnus were the dominant seagrasses in the subtidal zones...

  3. Geological and geophysical surveys of Visakhapatnam coast

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.C.S.; Rao, K.M.; Lakshminarayana, S.

    Continuous records of the total earth's magnetic field and the surface sediment samples from the ocean bottom have been collected off Ramakrishna Beach and Lawsons Bay along the Visakhapatnam Coast. The magnetic data has recorded significant...

  4. Identification of groundwater discharge in Cuddalore coast, Tamil Nadu using radium isotopes

    International Nuclear Information System (INIS)

    Diksha Chawla; Noble Jacob; Mohokar, H.V.

    2014-01-01

    For the optimal exploitation and management of coastal aquifers of Tamil Nadu, it is essential to evaluate the groundwater outflow into the sea also called as submarine groundwater discharge. In this study, radium isotopes ( 223,224 Ra) were employed to understand the groundwater discharge in coastal areas of Cuddalore district, Tamil Nadu. Sea water samples (100 L) were collected from various locations of Cuddalore coast in October 2011 and passed through Mn-impregnated acrylic fiber columns. These acrylic columns were analyzed for 223,224 Ra activities using radium delayed coincidence counter. The observed higher activities of 223,224 Ra excess (0.02 ± 0.001-3.28 ± 0.16 and 64 ± 3-380 ± 19 mBq/100 L respectively) indicate that groundwater discharge occurs in this coastal region. (author)

  5. Identification of groundwater discharge in Cuddalore Coast, Tamil Nadu using radium isotopes

    International Nuclear Information System (INIS)

    Diksha; Jacob, Noble; Mohokar, H.V.

    2013-01-01

    For the optimal exploitation and management of coastal aquifers of Tamil Nadu, it is essential to evaluate the groundwater outflow into the sea. In this study, radium isotopes ( 223,224 Ra) were employed to understand the groundwater discharge in coastal areas of Cuddalore district, Tamil Nadu. Sea water samples (100 L) were collected from various locations of Cuddalore coast in October 2011 and passed through Mn-impregnated acrylic fiber columns. These acrylic columns were analyzed for 223,224 Ra activities using Radium Delayed Coincidence Counter (RaDeCC). The observed higher activities of 223,224 Ra (0-0.18 and 3.84-22.77 dpm/L respectively) indicate that groundwater discharge occurs in this coastal region. (author)

  6. Connectivity for underway Coast Guard patrol boats

    OpenAIRE

    Busch, Gregory C.

    1997-01-01

    Approved for public release; distribution is unlimited This thesis examines the US Coast Guard patrol boat's ability to effectively exchange operational data while underway. The patrol boat is currently unable to obtain tactical law enforcement information from the central Law Enforcement Information System 2 (LEIS 2) database while on patrol. LEIS 2 provides access to law enforcement information from Coast Guard, FBI, and state and local law enforcement agencies. Availability of this info...

  7. Virginia Coast Reserve 2007 Remote Sensing Experiment

    Science.gov (United States)

    2012-03-09

    beaches, maritime forests , wetlands, tidal flats, and coastal lagoons ; - Natural lands and built up areas along Cape Charles, VA are...representative of barrier island coasts , worldwide; and - It is a major natural resource for the Mid Atlantic Region. Imagery-derived information for...support Joint Logistics Over the Shore. This experiment uses the VCR to study a barrier island coast with coastal lagoons , tidal inlets, and

  8. Geophysical Characterization of Serpentinite Hosted Hydrogeology at the McLaughlin Natural Reserve, Coast Range Ophiolite

    Science.gov (United States)

    Ortiz, Estefania; Tominaga, Masako; Cardace, Dawn; Schrenk, Matthew O.; Hoehler, Tori M.; Kubo, Michael D.; Rucker, Dale F.

    2018-01-01

    Geophysical remote sensing both on land and at sea has emerged as a powerful approach to characterize in situ water-rock interaction processes in time and space. We conducted 2-D Electrical Resistivity Tomography (ERT) surveys to investigate in situ hydrogeological architecture within the Jurassic age tectonic mélange portion of the Coast Range Ophiolite Microbial Observatory (CROMO) during wet and dry seasons, where water-rock interactive processes are thought to facilitate a subsurface biosphere. Integrating survey tracks traversing two previously drilled wells, QV1,1 and CSW1,1 at the CROMO site with wireline and core data, and the Serpentine Valley site, we successfully documented changes in hydrogeologic properties in the CROMO formation, i.e., lateral and vertical distribution of conductive zones and their temporal behavior that are dependent upon seasonal hydrology. Based on the core-log-ERT integration, we propose a hydrogeological architectural model, in which the formation is composed of three distinct aquifer systems: perched serpentinite aquifer without seasonal dependency (shallow system), well-cemented serpentine confining beds with seasonal dependency (intermediate system), serpentinite aquifer (deep system), and the ultramafic basement that acts as a quasi-aquiclude (below the deep system). The stunning contrast between the seasonality in the surface water availability and groundwater storativity in the formation allowed us to locate zones where serpentinite weathering and possibly deeper serpentinization processes might have taken place. We based our findings primarily on lithological composition and the distribution of the conductive formation, our work highlights the link between serpentinite weathering processes and possible sources of water in time and space.

  9. Pumping Test Determination of Unsaturated Aquifer Properties

    Science.gov (United States)

    Mishra, P. K.; Neuman, S. P.

    2008-12-01

    Tartakovsky and Neuman [2007] presented a new analytical solution for flow to a partially penetrating well pumping at a constant rate from a compressible unconfined aquifer considering the unsaturated zone. In their solution three-dimensional, axially symmetric unsaturated flow is described by a linearized version of Richards' equation in which both hydraulic conductivity and water content vary exponentially with incremental capillary pressure head relative to its air entry value, the latter defining the interface between the saturated and unsaturated zones. Both exponential functions are characterized by a common exponent k having the dimension of inverse length, or equivalently a dimensionless exponent kd=kb where b is initial saturated thickness. The authors used their solution to analyze drawdown data from a pumping test conducted by Moench et al. [2001] in a Glacial Outwash Deposit at Cape Cod, Massachusetts. Their analysis yielded estimates of horizontal and vertical saturated hydraulic conductivities, specific storage, specific yield and k . Recognizing that hydraulic conductivity and water content seldom vary identically with incremental capillary pressure head, as assumed by Tartakovsky and Neuman [2007], we note that k is at best an effective rather than a directly measurable soil parameter. We therefore ask to what extent does interpretation of a pumping test based on the Tartakovsky-Neuman solution allow estimating aquifer unsaturated parameters as described by more common constitutive water retention and relative hydraulic conductivity models such as those of Brooks and Corey [1964] or van Genuchten [1980] and Mualem [1976a]? We address this question by showing how may be used to estimate the capillary air entry pressure head k and the parameters of such constitutive models directly, without a need for inverse unsaturated numerical simulations of the kind described by Moench [2003]. To assess the validity of such direct estimates we use maximum

  10. Conduit enlargement in an eogenetic karst aquifer

    Science.gov (United States)

    Moore, Paul J.; Martin, Jonathan B.; Screaton, Elizabeth J.; Neuhoff, Philip S.

    2010-11-01

    SummaryMost concepts of conduit development have focused on telogenetic karst aquifers, where low matrix permeability focuses flow and dissolution along joints, fractures, and bedding planes. However, conduits also exist in eogenetic karst aquifers, despite high matrix permeability which accounts for a significant component of flow. This study investigates dissolution within a 6-km long conduit system in the eogenetic Upper Floridan aquifer of north-central Florida that begins with a continuous source of allogenic recharge at the Santa Fe River Sink and discharges from a first-magnitude spring at the Santa Fe River Rise. Three sources of water to the conduit include the allogenic recharge, diffuse recharge through epikarst, and mineralized water upwelling from depth. Results of sampling and inverse modeling using PHREEQC suggest that dissolution within the conduit is episodic, occurring only during 30% of 16 sampling times between March 2003 and April 2007. During low flow conditions, carbonate saturated water flows from the matrix to the conduit, restricting contact between undersaturated allogenic water with the conduit wall. When gradients reverse during high flow conditions, undersaturated allogenic recharge enters the matrix. During these limited periods, estimates of dissolution within the conduit suggest wall retreat averages about 4 × 10 -6 m/day, in agreement with upper estimates of maximum wall retreat for telogenetic karst. Because dissolution is episodic, time-averaged dissolution rates in the sink-rise system results in a wall retreat rate of about 7 × 10 -7 m/day, which is at the lower end of wall retreat for telogenetic karst. Because of the high permeability matrix, conduits in eogenetic karst thus enlarge not just at the walls of fractures or pre-existing conduits such as those in telogenetic karst, but also may produce a friable halo surrounding the conduits that may be removed by additional mechanical processes. These observations stress the

  11. CO2/Brine transport into shallow aquifers along fault zones.

    Science.gov (United States)

    Keating, Elizabeth H; Newell, Dennis L; Viswanathan, Hari; Carey, J W; Zyvoloski, G; Pawar, Rajesh

    2013-01-02

    Unintended release of CO(2) from carbon sequestration reservoirs poses a well-recognized risk to groundwater quality. Research has largely focused on in situ CO(2)-induced pH depression and subsequent trace metal mobilization. In this paper we focus on a second mechanism: upward intrusion of displaced brine or brackish-water into a shallow aquifer as a result of CO(2) injection. Studies of two natural analog sites provide insights into physical and chemical mechanisms controlling both brackish water and CO(2) intrusion into shallow aquifers along fault zones. At the Chimayó, New Mexico site, shallow groundwater near the fault is enriched in CO(2) and, in some places, salinity is significantly elevated. In contrast, at the Springerville, Arizona site CO(2) is leaking upward through brine aquifers but does not appear to be increasing salinity in the shallow aquifer. Using multiphase transport simulations we show conditions under which significant CO(2) can be transported through deep brine aquifers into shallow layers. Only a subset of these conditions favor entrainment of salinity into the shallow aquifer: high aspect-ratio leakage pathways and viscous coupling between the fluid phases. Recognition of the conditions under which salinity is favored to be cotransported with CO(2) into shallow aquifers will be important in environmental risk assessments.

  12. 33 CFR 23.10 - Coast Guard emblem.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Coast Guard emblem. 23.10 Section... DISTINCTIVE MARKINGS FOR COAST GUARD VESSELS AND AIRCRAFT § 23.10 Coast Guard emblem. (a) The distinctive emblem of the Coast Guard shall be as follows: On a disc the shield of the Coat of Arms of the United...

  13. 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

  14. Managed aquifer recharge: rediscovering nature as a leading edge technology.

    Science.gov (United States)

    Dillon, P; Toze, S; Page, D; Vanderzalm, J; Bekele, E; Sidhu, J; Rinck-Pfeiffer, S

    2010-01-01

    Use of Managed Aquifer Recharge (MAR) has rapidly increased in Australia, USA, and Europe in recent years as an efficient means of recycling stormwater or treated sewage effluent for non-potable and indirect potable reuse in urban and rural areas. Yet aquifers have been relied on knowingly for water storage and unwittingly for water treatment for millennia. Hence if 'leading edge' is defined as 'the foremost part of a trend; a vanguard', it would be misleading to claim managed aquifer recharge as a leading edge technology. However it has taken a significant investment in scientific research in recent years to demonstrate the effectiveness of aquifers as sustainable treatment systems to enable managed aquifer recharge to be recognised along side engineered treatment systems in water recycling. It is a 'cross-over' technology that is applicable to water and wastewater treatment and makes use of passive low energy processes to spectacularly reduce the energy requirements for water supply. It is robust within limits, has low cost, is suitable from village to city scale supplies, and offers as yet almost untapped opportunities for producing safe drinking water supplies where they do not yet exist. It will have an increasingly valued role in securing water supplies to sustain cities affected by climate change and population growth. However it is not a universal panacea and relies on the presence of suitable aquifers and sources of water together with effective governance to ensure human health and environment protection and water resources planning and management. This paper describes managed aquifer recharge, illustrates its use in Australia, outlining economics, guidelines and policies, and presents some of the knowledge about aquifer treatment processes that are revealing the latent value of aquifers as urban water infrastructure and provide a driver to improving our understanding of urban hydrogeology.

  15. Modelling stream aquifer seepage in an alluvial aquifer: an improved loosing-stream package for MODFLOW

    Science.gov (United States)

    Osman, Yassin Z.; Bruen, Michael P.

    2002-07-01

    Seepage from a stream, which partially penetrates an unconfined alluvial aquifer, is studied for the case when the water table falls below the streambed level. Inadequacies are identified in current modelling approaches to this situation. A simple and improved method of incorporating such seepage into groundwater models is presented. This considers the effect on seepage flow of suction in the unsaturated part of the aquifer below a disconnected stream and allows for the variation of seepage with water table fluctuations. The suggested technique is incorporated into the saturated code MODFLOW and is tested by comparing its predictions with those of a widely used variably saturated model, SWMS_2D simulating water flow and solute transport in two-dimensional variably saturated media. Comparisons are made of both seepage flows and local mounding of the water table. The suggested technique compares very well with the results of variably saturated model simulations. Most currently used approaches are shown to underestimate the seepage and associated local water table mounding, sometimes substantially. The proposed method is simple, easy to implement and requires only a small amount of additional data about the aquifer hydraulic properties.

  16. Functioning of the Primary Aquifer Relating to the Maider Basin, Morocco: Case of the Ordovician aquifer.

    Science.gov (United States)

    Ben-said, E.; Boukdir, A.; Mahboub, A.; Younsi, A.; Zitouni, A.; Alili, L.; Ikhmerdi, H.

    2018-05-01

    The basin of Maider is limited northly by the vast ensemble Oriental Saghro-Ougnate, from the east by the Tafilalet plain, from the west by the oriental Jbel Bani, finally from the south and south-east by the Cretaceous Hamada of Kern-Kem. During last decades, groundwater in the basin of Maider, is confronting degradation in both cases: Quantitative and qualitative, as a result of the drought, the overexploitation and the salinization. The aim of this action research is to understand the current state of water resources in the area of stady. At the end of this work, we can get the following conclusions: the general flow of the ordovician aquifer is always directed from the north to the south-east of the basin by following the principal axes of the wadis:Taghbalt, Hssiya and Fezzou. The recharge of the aquifer is primarily done, either by the underground flow, or by the surface runoff of torrential waters from the upstream of Jbel Saghro. The piezometric anomaly noticed at the level of Ait Saàdane, explained by overexploitation linked to the needs of irrigation water. The physicochemical approach for the Maider basin identifies two essential factors of the salinisation of groundwater: the dissolution of the aquifer which is rich in minerals with high temperature on the one hand, and the decrease of the piezometric surface due to the overexploitation and drought on the other hand.

  17. Hydrologic time and sustainability of shallow aquifers

    Science.gov (United States)

    Back, William; ,

    1994-01-01

    Measurement of water and short intervals of time are coeval events that began about 6000 BC in Mesopotamia. Even though time and hydrology have been intimately entwined, with time terms in the denominator of many hydrologic parameters, hydrology's a priori claim to time has not been consummated. Moreover, time takes on a greater importance now than in the past as the focus shifts to small site-scale aquifers whose sustainability can be physically and chemically threatened. One of the challenges for research in hydrogeology is to establish time scales for hydrologic phenomena such as infiltration rates, groundwater flow rates, rates of organic and inorganic reactions, and rates of groundwater withdrawal over the short term, and the long term and to understand the consequences of these various time scales. Credible monitoring programs must consider not only the spatial scale, but also the time scale of the phenomena being monitored.

  18. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

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

    1991-01-01

    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......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...

  19. Optimal Aquifer Pumping Policy to Reduce Contaminant Concentration

    Directory of Open Access Journals (Sweden)

    Ali Abaei

    2012-01-01

    Full Text Available Different sources of ground water contamination lead to non-uniform distribution of contaminant concentration in the aquifer. If elimination or containment of pollution sources was not possible, the distribution of contaminant concentrations could be modified in order to eliminate peak concentrations using optimal water pumping discharge plan. In the present investigation Visual MODFLOW model was used to simulate the flow and transport in a hypothetic aquifer. Genetic Algorithm (GA also was applied to optimize the location and pumping flow rate of wells in order to reduce contaminants peak concentrations in aquifer.

  20. FutureCoast: "Listen to your futures"

    Science.gov (United States)

    Pfirman, S. L.; Eklund, K.; Thacher, S.; Orlove, B. S.; Diane Stovall-Soto, G.; Brunacini, J.; Hernandez, T.

    2014-12-01

    Two science-arts approaches are emerging as effective means to convey "futurethinking" to learners: systems gaming and experiential futures. FutureCoast exemplifies the latter: by engaging participants with voicemails supposedly leaking from the cloud of possible futures, the storymaking game frames the complexities of climate science in relatable contexts. Because participants make the voicemails themselves, FutureCoast opens up creative ways for people to think about possibly climate-changed futures and personal ways to talk about them. FutureCoast is a project of the PoLAR Partnership with a target audience of informal adult learners primarily reached via mobile devices and online platforms. Scientists increasingly use scenarios and storylines as ways to explore the implications of environmental change and societal choices. Stories help people make connections across experiences and disciplines and link large-scale events to personal consequences. By making the future seem real today, FutureCoast's framework helps people visualize and plan for future climate changes. The voicemails contributed to FutureCoast are spread through the game's intended timeframe (2020 through 2065). Based on initial content analysis of voicemail text, common themes include ecosystems and landscapes, weather, technology, societal issues, governance and policy. Other issues somewhat less frequently discussed include security, food, industry and business, health, energy, infrastructure, water, economy, and migration. Further voicemail analysis is examining: temporal dimensions (salient time frames, short vs. long term issues, intergenerational, etc.), content (adaptation vs. mitigation, challenges vs. opportunities, etc.), and emotion (hopeful, resigned, etc. and overall emotional context). FutureCoast also engaged audiences through facilitated in-person experiences, geocaching events, and social media (Tumblr, Twitter, Facebook, YouTube). Analysis of the project suggests story

  1. New methodology for aquifer influx status classification for single wells in a gas reservoir with aquifer support

    Directory of Open Access Journals (Sweden)

    Yong Li

    2016-10-01

    Full Text Available For gas reservoirs with strong bottom or edge aquifer support, the most important thing is avoiding aquifer breakthrough in a gas well. Water production in gas wells does not only result in processing problems in surface facilities, but it also explicitly reduces well productivity and reservoir recovery. There are a lot of studies on the prediction of water breakthrough time, but they are not completely practicable due to reservoir heterogeneity. This paper provides a new method together with three diagnostic curves to identify aquifer influx status for single gas wells; the aforementioned curves are based on well production and pressure data. The whole production period of a gas well can be classified into three periods based on the diagnostic curves: no aquifer influx period, early aquifer influx period, and middle-late aquifer influx period. This new method has been used for actual gas well analysis to accurately identify gas well aquifer influx status and the water breakthrough sequence of all wells in the same gas field. Additionally, the evaluation results are significantly beneficial for well production rate optimization and development of an effective gas field.

  2. Isotopic study of the Continental Intercalaire aquifer and its relationship with other aquifers of the northern Sahara

    International Nuclear Information System (INIS)

    Gonfiantini, R.; Sauzay, G.; Payne, B.R.; Conrad, G.; Fontes, J.Ch.

    1974-01-01

    The Northern Sahara contains several aquifers, the largest of which is that of the Continental Intercalaire formations. In its eastern part the aquifer is confined and presents a very homogeneous isotopic composition. The 14 C activity is low or zero except in the outcrop zones of the north (Saharan Atlas), the east (Dahar) and the south (Tinrhert), all of which are recharge zones. In these areas the isotopic composition does not differ appreciably from that of the old water in the confined part of the aquifer. In the western part, where the reservoir outcrops widely, the 14 C activities show the extent of the local recharge. The heavy isotope content indicates the overflow of the surface aquifer of the western Grand Erg into the Continental Intercalaire over the whole Gourara front. The mixtures thus formed pass under the Tademait and drain towards the Touat. In the resurgence zone of the Gulf of G abes in Tunisia the heavy-isotope content confirms the recharging of the aquifer of the Complex terminal by drainage of water from the Continental Intercalaire through the El-Hamma fault system. The water then runs eastwards, mixing with local contributions. The marine Miocene confined aquifer of Zarzis-Djerba in the Gulf of Gabes receives no contribution from the Continental Intercalaire. The water in the aquifer of the western Grand Erg indicates an evaporation mechanism, probably peculiar to the dune systems, which gives rise to heavy-isotope enrichment compared with the recharge of other types of formations. (author) [fr

  3. 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; 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

  4. Factors Affecting Public-Supply Well Vulnerability in Two Karst Aquifers

    OpenAIRE

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

    2014-01-01

    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 nearb...

  5. Identifying Stream/Aquifer Exchange by Temperature Gradient in a Guarani Aquifer System Outcrop Zone

    Science.gov (United States)

    Wendland, E.; Rosa, D. M. S.; Anache, J. A. A.; Lowry, C.; Lin, Y. F. F.

    2017-12-01

    Recharge of the Guarani Aquifer System (GAS) in South America is supposed to occur mainly in the outcrop zones, where the GAS appears as an unconfined aquifer (10% of the 1.2 Million km2 aquifer extension). Previous evaluations of recharge are based essentially on water balance estimates for the whole aquifer area or water table fluctuations in monitoring wells. To gain a more detailed understanding of the recharge mechanisms the present work aimed to study the stream aquifer interaction in a watershed (Ribeirão da Onça) at an outcrop zone. Two Parshall flumes were installed 1.3 km apart for discharge measurement in the stream. Along this distance an optic fiber cable was deployed to identify stretches with gaining and losing behavior. In order to estimate groundwater discharge in specific locations, 8 temperature sticks were set up along the stream reach to measure continuously the vertical temperature gradient. A temperature probe with 4 thermistors was also used to map the shallow streambed temperature gradient manually along the whole distance. The obtained results show a discharge difference of 250 m3/h between both flumes. Since the last significant rainfall (15 mm) in the watershed occurred 3 months ago, this value can be interpreted as the base flow contribution to the stream during the dry season. Given the temperature difference between groundwater ( 24oC) and surface water ( 17oC) the fiber-optic distributed temperature sensing (FO-DTS) allowed the identification of stretches with gaining behavior. Temperature gradients observed at the streambed varied between 0.67 and 14.33 oC/m. The study demonstrated that heat may be used as natural tracer even in tropical conditions, where the groundwater temperature is higher than the surface water temperature during the winter. The obtained results show that the discharge difference between both flumes can not be extrapolated without detailed analysis. Gaining and loosing stretches have to be identified on order

  6. Coast Live Oak Thinning Study in the Central Coast of California

    Science.gov (United States)

    Norman H. Pillsbury; Michael J. DeLasaux; Timothy R. Plumb

    1987-01-01

    Abstract: Along-term thinning study was established in ten stands of coast live oak (Quercus agrifolia N in the Central Coast of California. Information about diameter, basal area, and volume growth and yield is being obtained from unthinned control plots and from plots thinned to 50 and 100 square feet of basal area per acre. Descriptive information was also collected...

  7. Cabira rangarajani n. sp. (Polychaeta: Pilargidae) from the Goa coast, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, Sumit; Harkantra, S.N.; Salazar-Vallejo, S.I.

    Cabira rangarajani n. sp., is described from the Goa coast, in central west coast of India. It differs from C. brevicirris (Rangarajan, 1964), by having a single type of neurochaetae while the other species has three types. The new species also...

  8. 75 FR 61102 - Magnuson-Stevens Act Provisions; Fisheries Off West Coast States; Pacific Coast Groundfish...

    Science.gov (United States)

    2010-10-04

    ... opportunities to harvest available healthy stocks and meet the objective of the Pacific Coast Groundfish FMP to... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 660 [Docket No... Coast Groundfish Fishery; Inseason Adjustments to Fishery Management Measures AGENCY: National Marine...

  9. 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...

  10. Analytical solution of groundwater waves in unconfined aquifers with ...

    Indian Academy of Sciences (India)

    Selva Balaji Munusamy

    2017-07-29

    Jul 29, 2017 ... higher-order Boussinesq equation. The homotopy perturbation solution is derived using a virtual perturbation .... reality, seepage face formation is common for tide–aquifer interaction problems. To simplify the complexity of the.

  11. Temporal geoelectric behaviour of dyke aquifers in northern Deccan ...

    Indian Academy of Sciences (India)

    These studies revealed changes in field characters, their attitudes, thickness and structure ... logists. However, information on the relation- .... the water table aquifer occurs at shallow depth .... from the field was processed and modelled using.

  12. Aquifers productivity in the Pan-African context

    Indian Academy of Sciences (India)

    , 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 ...

  13. Radial flow towards well in leaky unconfined aquifer

    Science.gov (United States)

    Mishra, P. K.; Kuhlman, K. L.

    2012-12-01

    An analytical solution is developed for three-dimensional flow towards a partially penetrating large- diameter well in an unconfined aquifer bounded below by a leaky aquitard of finite or semi-infinite extent. The analytical solution is derived using Laplace and Hankel transforms, then inverted numerically. Existing solutions for flow in leaky unconfined aquifers neglect the unsaturated zone following an assumption of instantaneous drainage due to Neuman. We extend the theory of leakage in unconfined aquifers by (1) including water flow and storage in the unsaturated zone above the water table, and (2) allowing the finite-diameter pumping well to partially penetrate the aquifer. The investigation of model-predicted results shows that aquitard leakage leads to significant departure from the unconfined solution without leakage. The investigation of dimensionless time-drawdown relationships shows that the aquitard drawdown also depends on unsaturated zone properties and the pumping-well wellbore storage effects.

  14. Aquifer Vulnerability Investigation Using Geoelectric Method in Parts ...

    African Journals Online (AJOL)

    The generated longitudinal conductance map showed poor protective capacity ... capacity makes the aquifer in the study area vulnerable to contamination ..... Sedimentation and Structure of the Niger Delta. ... Direct application of the Dar.

  15. Borehole depth and regolith aquifer hydraulic characteristics of ...

    African Journals Online (AJOL)

    EJIRO

    composition tend to exhibit similar hydraulic characteristics. But the poor performance of ... mum borehole depth in the regolith aquifer for the area and also reveals that ..... most important end products of chemical weathering of rocks of granitic ...

  16. Redox Conditions in Selected Principal Aquifers of the United States

    Science.gov (United States)

    McMahon, P.B.; Cowdery, T.K.; Chapelle, F.H.; Jurgens, B.C.

    2009-01-01

    Reduction/oxidation (redox) processes affect the quality of groundwater in all aquifer systems. Redox processes can alternately mobilize or immobilize potentially toxic metals associated with naturally occurring aquifer materials, contribute to the degradation or preservation of anthropogenic contami-nants, and generate undesirable byproducts, such as dissolved manganese (Mn2+), ferrous iron (Fe2+), hydrogen sulfide (H2S), and methane (CH4). Determining the kinds of redox processes that occur in an aquifer system, documenting their spatial distribution, and understanding how they affect concentrations of natural or anthropogenic contaminants are central to assessing and predicting the chemical quality of groundwater. This Fact Sheet extends the analysis of U.S. Geological Survey authors to additional principal aquifer systems by applying a framework developed by the USGS to a larger set of water-quality data from the USGS national water databases. For a detailed explanation, see the 'Introduction' in the Fact Sheet.

  17. 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.

  18. Fate of triclocarban during soil aquifer treatment: Soil column studies

    KAUST Repository

    Essandoh, H. M K; Tizaoui, Chedly; Mohamed, Mostafa H A; Amy, Gary L.; Brdjanovic, Damir

    2010-01-01

    There are current concerns about the presence of persistent chemicals in recharge water used in soil aquifer treatment systems. Triclocarban (TCC) has been reported as a persistent, high production volume chemical with the potential to bioaccumulate

  19. Soil aquifer treatment of artificial wastewater under saturated conditions

    KAUST Repository

    Essandoh, H. M K; Tizaoui, Chedly; Mohamed, Mostafa H A; Amy, Gary L.; Brdjanovic, Damir

    2011-01-01

    A 2000 mm long saturated laboratory soil column was used to simulate soil aquifer treatment under saturated conditions to assess the removal of chemical and biochemical oxygen demand (COD and BOD), dissolved organic carbon (DOC), nitrogen

  20. Exploring deep potential aquifer in water scarce crystalline rocks

    Indian Academy of Sciences (India)

    out to explore deep groundwater potential zone in a water scarce granitic area. As existing field condi- ... Decision support tool developed in granitic ter- .... cially in terms of fracture system, the aquifer char- acteristics ... Methodologies used.

  1. Water levels of the Ozark aquifer in northern Arkansas, 2013

    Science.gov (United States)

    Schrader, Tony P.

    2015-07-13

    The Ozark aquifer is the largest aquifer, both in area of outcrop and thickness, and the most important source of freshwater in the Ozark Plateaus physiographic province, supplying water to northern Arkansas, southeastern Kansas, southern Missouri, and northeastern Oklahoma. The study area includes 16 Arkansas counties lying completely or partially within the Ozark Plateaus of the Interior Highlands major physiographic division. The U.S. Geological Survey, in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey, conducted a study of water levels in the Ozark aquifer within Arkansas. This report presents a potentiometric-surface map of the Ozark aquifer within the Ozark Plateaus of northern Arkansas, representing water-level conditions for the early spring of 2013 and selected water-level hydrographs.

  2. Evaluation of karstic aquifers contribution to streams by the statistical ...

    Indian Academy of Sciences (India)

    and water budget balance, have been applied to assess ... Keywords. Recession curve; karstic aquifer; western Mediterranean Basin–Turkey; data analysis; hydrology; modelling. .... on the solution of the general differential equa- tion of the ...

  3. Managing the unseen: Langebaan Road Aquifer System | du Plessis ...

    African Journals Online (AJOL)

    The effective management of groundwater resources is a critical aspect to ... The paper highlights specific problems experienced with the implementation of the Langebaan Road Aquifer well-field as an integrated water resource, and the ...

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

    African Journals Online (AJOL)

    Bheema

    Research Article ... Based on borehole and structure data presence of multilayer aquifers, their .... Shape of the clasts varies from angular, elliptical and ..... Water quality investigation (i.e. for domestic purpose) is also recommended. 6.

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

    African Journals Online (AJOL)

    user

    2009-05-15

    May 15, 2009 ... African Journal of Environmental Science and Technology Vol. 3 (5), pp. 141-148 ..... hydrogeological study of the coastal sedimentary basin of. Togo intended to ... isotopic study and modeling of the Paleocene aquifer in the.

  6. Simulation of sea water intrusion in coastal aquifers

    Indian Academy of Sciences (India)

    dependent miscible flow and transport modelling approach for simulation of seawater intrusion in coastal aquifers. A nonlinear optimization-based simulation methodology was used in this study. Various steady state simulations are performed for a ...

  7. ZVI (Fe0) desalination: catalytic partial desalination of saline aquifers

    Science.gov (United States)

    Antia, David D. J.

    2018-05-01

    Globally, salinization affects between 100 and 1000 billion m3 a-1 of irrigation water. The discovery that zero valent iron (ZVI, Fe0) could be used to desalinate water (using intra-particle catalysis in a diffusion environment) raises the possibility that large-scale in situ desalination of aquifers could be undertaken to support agriculture. ZVI desalination removes NaCl by an adsorption-desorption process in a multi-stage cross-coupled catalytic process. This study considers the potential application of two ZVI desalination catalyst types for in situ aquifer desalination. The feasibility of using ZVI catalysts when placed in situ within an aquifer to produce 100 m3 d-1 of partially desalinated water from a saline aquifer is considered.

  8. Web-based global inventory of managed aquifer recharge applications

    NARCIS (Netherlands)

    Stefan, Catalin; Ansems, Nienke

    2017-01-01

    Managed aquifer recharge (MAR) is being successfully implemented worldwide for various purposes: to increase groundwater storage, improve water quality, restore groundwater levels, prevent salt water intrusion, manage water distribution systems, and enhance ecological benefits. To better understand

  9. Determining hydraulic parameters of a karst aquifer using unique ...

    African Journals Online (AJOL)

    2014-07-15

    Jul 15, 2014 ... 1 Faculty of Natural Sciences, Potchefstroom Campus, North-West University, ... a first-ever attempt to utilise various sets of unique historical data ..... Even though the aquifer shows characteristics of all major ...... Earth Sci.

  10. 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

  11. Groundwater Quality: Analysis of Its Temporal and Spatial Variability in a Karst Aquifer.

    Science.gov (United States)

    Pacheco Castro, Roger; Pacheco Ávila, Julia; Ye, Ming; Cabrera Sansores, Armando

    2018-01-01

    This study develops an approach based on hierarchical cluster analysis for investigating the spatial and temporal variation of water quality governing processes. The water quality data used in this study were collected in the karst aquifer of Yucatan, Mexico, the only source of drinking water for a population of nearly two million people. Hierarchical cluster analysis was applied to the quality data of all the sampling periods lumped together. This was motivated by the observation that, if water quality does not vary significantly in time, two samples from the same sampling site will belong to the same cluster. The resulting distribution maps of clusters and box-plots of the major chemical components reveal the spatial and temporal variability of groundwater quality. Principal component analysis was used to verify the results of cluster analysis and to derive the variables that explained most of the variation of the groundwater quality data. Results of this work increase the knowledge about how precipitation and human contamination impact groundwater quality in Yucatan. Spatial variability of groundwater quality in the study area is caused by: a) seawater intrusion and groundwater rich in sulfates at the west and in the coast, b) water rock interactions and the average annual precipitation at the middle and east zones respectively, and c) human contamination present in two localized zones. Changes in the amount and distribution of precipitation cause temporal variation by diluting groundwater in the aquifer. This approach allows to analyze the variation of groundwater quality controlling processes efficiently and simultaneously. © 2017, National Ground Water Association.

  12. Geochemical Characterization of the Upper and Middle Floridan Aquifer System, South Florida

    Science.gov (United States)

    Mirecki, J.; Richardson, E.; Bennett, M.; Hendel, J.

    2008-05-01

    Our study focus is to characterize the water quality and geochemical environment of the Floridan Aquifer System (FAS) throughout the regional flowpath. A synoptic survey of 21 wells (n=15, upper FAS; n=6 middle FAS) was supplemented by additional samples (n=11) obtained during exploratory well development at 4 aquifer storage recovery (ASR) pilot sites. Synoptic survey samples were analyzed intensively, yielding a dataset that consists of major and trace dissolved constituents (including metals), stable isotopes (δ18O, δ13C, δD, δ34S in sulfate and sulfide), carbon species (carbonate alkalinity and organic carbon), uranium-series radionuclides, nutrients, and selected microbes and pathogens. The objectives of this study are three-fold: 1) to provide baseline water-quality and geochemical information prior to initiation of ASR activities that are part of the Comprehensive Everglades Restoration Plan; 2) to quantify the major controls on geochemical evolution along upper and middle FAS flowpaths using geochemical modeling methods; and 3) to identify areas where water- quality may limit the feasibility of ASR methods in the FAS. Preliminary interpretations water quality changes along the regional FAS flowpath can be summarized as follows. Concentrations of dissolved constituents increase from north to south along the flow path; generally, the upper FAS has lower total dissolved solids than the middle FAS at locations where well pairs were analyzed. The redox environment changes from oxic to strongly anoxic, very close to the recharge area. Redox measurements, dissolved iron, sulfide, and sulfur isotope data are consistent with sulfate-reducing conditions. Uranium-series isotope concentrations and activities generally are below regulatory criteria, with few exceptions in both the upper and middle FAS. Areas with greater radionuclide activity occur primarily at distal flowpath locations or at the coast.

  13. Effect of nitrate addition on biorestoration of fuel-contaminated aquifer: Field demonstration

    International Nuclear Information System (INIS)

    Hutchins, S.R.; Downs, W.C.; Wilson, J.T.; Smith, G.B.; Kovacs, D.A.

    1991-01-01

    A spill of JP-4 jet fuel at the U.S. Coast Guard Air Station in Traverse City, Michigan, contaminated a water-table aquifer. An infiltration gallery (30 ft X 30 ft) was installed above a section of the aquifer containing 700 gal JP-4. Purge wells recirculated three million gallons of ground water per week through the infiltration gallery at a rate designed to raise the water table above the contaminated interval. Ground water containing ambient concentrations was first recirculated for 40 days. Concentrations of benzene in monitoring wells beneath the infiltration gallery were reduced from 760 to <1 micrograms/1. Concentrations of toluene, ethylbenzene, m,p-xylene, and o-xylene were reduced from 4500 to 17,840 to 44,2600 to 490, and 1400 to 260 micrograms/1, respectively. Average core concentrations of benzene, toluene, ethylbenzene, m,p-xylene, and o-xylene were reduced from 0.84 to 0.032, 33 to 0.13, 18 to 0.36, 58 to 7.4, and 26 to 3.2 mg/kg, respectively. Ground water amended with nitrate (10 mg/1 nitrate-nitrogen) and nutrients was then recirculated for 76 days. Final core concentrations of benzene, toluene, ethylbenzene, m,p-xylene and o-xylene were 0.017, 0.036, 0.019, 0.059, and 0.27 mg/kg, respectively. Final aqueous concentrations were <1 micrograms/1 for benzene and toluene, 6 micrograms/1 for ethylbenzene, and 20 to 40 micrograms/1 for the xylene isomers, in good agreement with predicted values based on residual fuel content and partitioning theory. Although alkylbenzene concentrations have been substantially reduced, the test plot is still contaminated with the weathered fuel. Based on stoichiometry, approximately 10 times more nitrate was consumed than could be accounted for by BTX degradation alone, indicating that other compounds were also degraded under denitrifying conditions

  14. Bio-remediation of aquifers polluted by chlorinated solvents

    International Nuclear Information System (INIS)

    Fayolle, F.

    1996-01-01

    Numerous cases of contamination of aquifers by chlorinated aliphatic solvents, largely utilized during the last decades, constitute a public health problem, because of the toxic effect of such compounds. Different types of aerobic or anaerobic bacteria are able to degrade these molecules. Processes of bio remediation are now experimented in order to restore polluted aquifers. We present here the microorganisms and the enzymatic reactions involved in the biodegradation of chlorinated solvents, and different examples of in situ bio remediation operations are described. (author)

  15. Variation of uranium isotopes in some carbonate aquifers

    International Nuclear Information System (INIS)

    Cowart, J.B.

    1980-01-01

    The 234 U/ 238 U alpha activity ratio (AR) and uranium concentrations are reported for 83 springs that issue from carbonate aquifers in Florida, Texas, Nevada-California, and Israel. Data for each aquifer fall within more or less mutually exclusive fields. In general, the spring in a humid climate have AR's approaching secular equilibrium, whereas those in more arid climates have AR's differing greatly from equilibrium

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

    International Nuclear Information System (INIS)

    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

  17. Drilling methods to keep the hydrogeological parameters of natural aquifer

    International Nuclear Information System (INIS)

    Chen Xiaoqin

    2004-01-01

    In hydrogeological drilling, how to keep the hydrogeological parameters of natural aquifer unchanged is a deeply concerned problem for the technicians, this paper introduces the methods taken by the state-owned 'Red Hill' geological company of Uzbekistan. By the research and contrast of different kinds of flush liquid, the company has found the methods to reduce the negative effects of drilling on the permeability of the vicinal aquifer. (author)

  18. 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.

  19. Interannual to multidecadal climate forcings on groundwater resources of the U.S. West Coast

    Science.gov (United States)

    Velasco, Elzie M.; Gurdak, Jason J.; Dickinson, Jesse; Ferré, T.P.A.; Corona, Claudia

    2017-01-01

    Study regionThe U.S. West Coast, including the Pacific Northwest and California Coastal Basins aquifer systems.Study focusGroundwater response to interannual to multidecadal climate variability has important implications for security within the water–energy–food nexus. Here we use Singular Spectrum Analysis to quantify the teleconnections between AMO, PDO, ENSO, and PNA and precipitation and groundwater level fluctuations. The computer program DAMP was used to provide insight on the influence of soil texture, depth to water, and mean and period of a surface infiltration flux on the damping of climate signals in the vadose zone.New hydrological insights for the regionWe find that PDO, ENSO, and PNA have significant influence on precipitation and groundwater fluctuations across a north-south gradient of the West Coast, but the lower frequency climate modes (PDO) have a greater influence on hydrologic patterns than higher frequency climate modes (ENSO and PNA). Low frequency signals tend to be preserved better in groundwater fluctuations than high frequency signals, which is a function of the degree of damping of surface variable fluxes related to soil texture, depth to water, mean and period of the infiltration flux. The teleconnection patterns that exist in surface hydrologic processes are not necessarily the same as those preserved in subsurface processes, which are affected by damping of some climate variability signals within infiltrating water.

  20. Renal Cell Toxicity of Water-Soluble Coal Extracts from the Gulf Coast

    Science.gov (United States)

    Ojeda, A. S.; Ford, S.; Ihnat, M.; Gallucci, R. M.; Philp, P. R.

    2017-12-01

    In the Gulf Coast, many rural residents rely on private well water for drinking, cooking, and other domestic needs. A large portion of this region contains lignite coal deposits within shallow aquifers that potentially leach organic matter into the water supply. It is proposed that the organic matter leached from low-rank coal deposits contributes to the development of kidney disease, however, little work has been done to investigate the toxicity of coal extracts. In this study, human kidney cells (HK-2) were exposed to water-soluble extracts of Gulf Coast Coals to assess toxicity. Cell viability was measured by direct counts of total and necrotic cells. A dose-response curve was used to generate IC50 values, and the extracts showed significant toxicity that ranged from 0.5% w/v to 3% w/v IC50. The most toxic extract was from Louisiana where coal-derived organic material has been previously linked to high incidents of renal pelvic cancer (RPC). Although the toxic threshold measured in this study is significantly higher than the concentration of organic matter in the groundwater, typically affected areas may consume contaminated water over a lifetime. It is possible that the cumulative toxic effects of coal-derived material contribute to the development of disease.

  1. Transient well flow in leaky multiple-aquifer systems

    Science.gov (United States)

    Hemker, C. J.

    1985-10-01

    A previously developed eigenvalue analysis approach to groundwater flow in leaky multiple aquifers is used to derive exact solutions for transient well flow problems in leaky and confined systems comprising any number of aquifers. Equations are presented for the drawdown distribution in systems of infinite extent, caused by wells penetrating one or more of the aquifers completely and discharging each layer at a constant rate. Since the solution obtained may be regarded as a combined analytical-numerical technique, a type of one-dimensional modelling can be applied to find approximate solutions for several complicating conditions. Numerical evaluations are presented as time-drawdown curves and include effects of storage in the aquitard, unconfined conditions, partially penetrating wells and stratified aquifers. The outcome of calculations for relatively simple systems compares very well with published corresponding results. The proposed multilayer solution can be a valuable tool in aquifer test evaluation, as it provides the analytical expression required to enable the application of existing computer methods to the determination of aquifer characteristics.

  2. Sustainable Capture: Concepts for Managing Stream-Aquifer Systems.

    Science.gov (United States)

    Davids, Jeffrey C; Mehl, Steffen W

    2015-01-01

    Most surface water bodies (i.e., streams, lakes, etc.) are connected to the groundwater system to some degree so that changes to surface water bodies (either diversions or importations) can change flows in aquifer systems, and pumping from an aquifer can reduce discharge to, or induce additional recharge from streams, springs, and lakes. The timescales of these interactions are often very long (decades), making sustainable management of these systems difficult if relying only on observations of system responses. Instead, management scenarios are often analyzed based on numerical modeling. In this paper we propose a framework and metrics that can be used to relate the Theis concepts of capture to sustainable measures of stream-aquifer systems. We introduce four concepts: Sustainable Capture Fractions, Sustainable Capture Thresholds, Capture Efficiency, and Sustainable Groundwater Storage that can be used as the basis for developing metrics for sustainable management of stream-aquifer systems. We demonstrate their utility on a hypothetical stream-aquifer system where pumping captures both streamflow and discharge to phreatophytes at different amounts based on pumping location. In particular, Capture Efficiency (CE) can be easily understood by both scientists and non-scientist alike, and readily identifies vulnerabilities to sustainable stream-aquifer management when its value exceeds 100%. © 2014, National Ground Water Association.

  3. Gulf Coast Clean Energy Application Center

    Energy Technology Data Exchange (ETDEWEB)

    Dillingham, Gavin [Houston Advanced Research Center, TX (United States)

    2013-09-30

    The Gulf Coast Clean Energy Application Center was initiated to significantly improve market and regulatory conditions for the implementation of combined heat and power technologies. The GC CEAC was responsible for the development of CHP in Texas, Louisiana and Oklahoma. Through this program we employed a variety of outreach and education techniques, developed and deployed assessment tools and conducted market assessments. These efforts resulted in the growth of the combined heat and power market in the Gulf Coast region with a realization of more efficient energy generation, reduced emissions and a more resilient infrastructure. Specific t research, we did not formally investigate any techniques with any formal research design or methodology.

  4. Project Coast: eugenics in apartheid South Africa.

    Science.gov (United States)

    Singh, Jerome Amir

    2008-03-01

    It is a decade since the exposure of Project Coast, apartheid South Africa's covert chemical and biological warfare program. In that time, attention has been focused on several aspects of the program, particularly the production of narcotics and poisons for use against anti-apartheid activists and the proliferation of both chemical and biological weapons. The eugenic dimension of Project Coast has, by contrast, received scant attention. It is time to revisit the testimony that brought the suggestion of eugenic motives to light, reflect on some of the Truth and Reconciliation Commission's findings and search for lessons that can be taken from this troubled chapter in South Africa's history.

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

    Data.gov (United States)

    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...

  6. Water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    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...

  7. Exploration of an alluvial aquifer in Oman by time-domain electromagnetic sounding

    Science.gov (United States)

    Young, M. E.; de Bruijn, R. G. M.; Al-Ismaily, A. Salim

    One-third of the population of Oman depends upon groundwater extracted from the alluvium of the Batinah Plain, on the coast of the Gulf of Oman. Deep geophysical exploration techniques were used to determine the depth and nature of the alluvium and the boundaries of the aquifer. The base and structural controls of the alluvial basin at its contact with Tertiary marine sediments and Cretaceous ophiolite were mapped with seismic reflection data, recorded originally for oil exploration. The base of the alluvium dips northward from the foothills of the Northern Oman Mountains, reaching a maximum depth of 2000m at the coast. The varying facies of the alluvium are grossly characterised by different, overlapping ranges of electrical resistivity, depending largely on the clay content and degree of cementation. Resistivities near the coast are reduced by saline intrusion. These variations of resistivity were mapped with time-domain electromagnetic sounding along 400km of profile, to distinguish among the three zones of the alluvial aquifer. The wedge of saline intrusion was also delineated, up to 10km from the coast. The thickness of the saturated gravel aquifer ranges from 20-160m in an area greater than 600km2. Résumé Un tiers de la population d'Oman est alimenté par de l'eau souterraine pompée dans les alluvions de la plaine de Batinah, sur la côte du golfe d'Oman. Des techniques d'exploration géophysique profonde ont été mises en oeuvre pour déterminer la profondeur et la nature des alluvions et les limites de l'aquifère. La base et les contrôles structuraux du bassin alluvial au contact des sédiments marins tertiaires et des ophiolites crétacées ont été cartographiés à partir des données de sismique réflexion obtenues à l'origine pour la recherche pétrolière. La base des alluvions plonge vers le nord à partir du piémont du massif septentrional d'Oman, pour atteindre une profondeur maximale de 2000m sur la côte. Les divers faciès alluviaux

  8. Electrical Resistivity Imaging and Hydrodynamic Modeling of Convective Fingering in a Sabkha Aquifer

    Science.gov (United States)

    Van Dam, Remke; Eustice, Brian; Hyndman, David; Wood, Warren; Simmons, Craig

    2014-05-01

    Free convection, or fluid motion driven by density differences, is an important groundwater flow mechanism that can enhance transport and mixing of heat and solutes in the subsurface. Various issues of environmental and societal relevance are exacerbated convective mixing; it has been studied in the context of dense contaminant plumes, nuclear waste disposal, greenhouse gas sequestration, the impacts of sea level rise and saline intrusion on drinking water resources. The basic theory behind convective flow in porous media is well understood, but important questions regarding this process in natural systems remain unanswered. Most previous research on this topic has focused on theory and modeling, with only limited attention to experimental studies and field measurements. The few published studies present single snapshots, making it difficult to quantify transient changes in these systems. Non-invasive electrical methods have the potential to exploit the relation between solute concentrations and electrical conductance of a fluid, and thereby estimate fluid salinity differences in time and space. We present the results of a two-year experimental study at a shallow sabkha aquifer in the United Arab Emirates, about 50 km southwest of the city of Abu Dhabi along the coast of the Arabian Gulf, that was designed to explore the transient nature of free convection. Electrical resistivity tomography (ERT) data documented the presence of convective fingers following a significant rainfall event. One year later, the complex fingering pattern had completely disappeared. This observation is supported by analysis of the aquifer solute budget as well as hydrodynamic modeling of the system. The transient dynamics of the gravitational instabilities in the modeling results are in agreement with the timing observed in the time-lapse ERT data. Our experimental observations and modeling are consistent with the hypothesis that the instabilities arose from a dense brine that infiltrated

  9. Hydrogeochemical characterization and groundwater quality assessment in intruded coastal brine aquifers (Laizhou Bay, China).

    Science.gov (United States)

    Zhang, Xiaoying; Miao, Jinjie; Hu, Bill X; Liu, Hongwei; Zhang, Hanxiong; Ma, Zhen

    2017-09-01

    The aquifer in the coastal area of the Laizhou Bay is affected by salinization processes related to intense groundwater exploitation for brine resource and for agriculture irrigation during the last three decades. As a result, the dynamic balances among freshwater, brine, and seawater have been disturbed and the quality of groundwater has deteriorated. To fully understand the groundwater chemical distribution and evolution in the regional aquifers, hydrogeochemical and isotopic studies have been conducted based on the water samples from 102 observation wells. Groundwater levels and salinities in four monitoring wells are as well measured to inspect the general groundwater flow and chemical patterns and seasonal variations. Chemical components such as Na + , K + , Ca 2+ , Mg 2+ , Sr 2+ , Cl - , SO 4 2- , HCO 3 - , NO 3 - , F - , and TDS during the same period are analyzed to explore geochemical evolution, water-rock interactions, sources of salt, nitrate, and fluoride pollution in fresh, brackish, saline, and brine waters. The decreased water levels without typical seasonal variation in the southeast of the study area confirm an over-exploitation of groundwater. The hydrogeochemical characteristics indicate fresh-saline-brine-saline transition pattern from inland to coast where evaporation is a vital factor to control the chemical evolution. The cation exchange processes are occurred at fresh-saline interfaces of mixtures along the hydraulic gradient. Meanwhile, isotopic data indicate that the brine in aquifers was either originated from older meteoric water with mineral dissolution and evaporation or repeatedly evaporation of retained seawater with fresher water recharge and mixing in geological time. Groundwater suitability for drinking is further evaluated according to water quality standard of China. Results reveal high risks of nitrate and fluoride contamination. The elevated nitrate concentration of 560 mg/L, which as high as 28 times of the standard content

  10. 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. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  11. Geochemical processes in a calcareous sandstone aquifer during managed aquifer recharge with desalinated seawater

    Science.gov (United States)

    Ganot, Yonatan; Russak, Amos; Siebner, Hagar; Bernstein, Anat; Katz, Yoram; Guttman, Jospeh; Kurtzman, Daniel

    2017-04-01

    In the last three years we monitor Managed Aquifer Recharge (MAR) of post-treated desalinated seawater (PTDES) in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. The PTDES are stabilized with CaCO3 during post-treatment in the desalination plant and their chemical composition differs from those of any other water recharged to the aquifer and of the natural groundwater. We use suction cups in the unsaturated zone, shallow observation wells within the pond and production wells that encircles the MAR Menashe site, to study the geochemical processes during MAR with PTDES. Ion-enrichment (remineralization) of the recharged water was observed in both unsaturated zone and shallow observation wells samples. Enrichment occurs mainly in the first few meters below the pond surface by ion-exchange processes. Mg2+ enrichment is most prominent due to its deficiency in the PTDES. It is explained by ion-exchange with Ca2+, as the PTDES (enriched with Ca2+) infiltrates through a calcareous-sandstone aquifer with various amount of adsorbed Mg2+ (3-27 meq/kg). Hence, the higher concentration of Ca+2 in the PTDES together with its higher affinity to the sediments promotes the release of Mg2+ ions to the recharged water. Water isotopes analysis of the production wells were used to estimate residence time and mixing with local groundwater. At the end of 2016, it was found that the percentage of PTDES in adjacent down-gradient production wells was around 10%, while more distant or up-gradient wells show no mixing with PTDES. The distinct isotope contrast between the recharged desalinated seawater (δ2H=+11.2±0.2‰) and the local groundwater (δ2H ranged from -22.7 to -16.7‰) is a promising tool to evaluate future mixing processes at the Menshae MAR site. Using the Menashe MAR system for remineralization could be beneficial as a primary or complementary post-treatment technique. However, the sustainability of this process is

  12. Behaviour and fate of nine recycled water trace organics during managed aquifer recharge in an aerobic aquifer

    Science.gov (United States)

    Patterson, B. M.; Shackleton, M.; Furness, A. J.; Bekele, E.; Pearce, J.; Linge, K. L.; Busetti, F.; Spadek, T.; Toze, S.

    2011-03-01

    The fate of nine trace organic compounds was evaluated during a 12 month large-scale laboratory column experiment. The columns were packed with aquifer sediment and evaluated under natural aerobic and artificial anaerobic geochemical conditions, to assess the potential for natural attenuation of these compounds during aquifer passage associated with managed aquifer recharge (MAR). The nine trace organic compounds were bisphenol A (BPA), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR), carbamazepine, oxazepam, iohexol and iodipamide. In the low organic carbon content Spearwood sediment, all trace organics were non-retarded with retardation coefficients between 1.0 and 1.2, indicating that these compounds would travel at near groundwater velocities within the aquifer. The natural aerobic geochemical conditions provided a suitable environment for the rapid degradation for BPA, E2, iohexol (half life NDMA and NMOR) did not degrade under either aerobic or anaerobic aquifer geochemical conditions (half life > 50 days). Field-based validation experiments with carbamazepine and oxazepam also showed no degradation. If persistent trace organics are present in recycled waters at concentrations in excess of their intended use, natural attenuation during aquifer passage alone may not result in extracted water meeting regulatory requirements. Additional pre treatment of the recycled water would therefore be required.

  13. Uranium series geochemistry in aquifers: quantification of transport mechanisms of uranium and daughter products: the chalk aquifer (Champagne, France)

    International Nuclear Information System (INIS)

    Hubert, A.

    2005-09-01

    With the increase of contaminant flux of radionuclides in surface environment (soil, river, aquifer...), there is a need to understand and model the processes that control the distribution of uranium and its daughter products during transport within aquifers. We have used U-series disequilibria as an analogue for the transport of uranium and its daughter products in aquifer to understand such mechanisms. The measurements of uranium ( 234 U et 238 U), thorium ( 230 Th et 232 Th), 226 Ra and 222 Rn isotopes in the solid and liquid phases of the chalk aquifer in Champagne (East of France) allows us to understand the processes responsible for fractionation within the uranium decay chain. Fractionations are induced by physical and chemical properties of the elements (leaching, adsorption) but also by radioactive properties (recoil effect during α-decay). For the first time a comprehensive sampling of the solid phase has been performed, allowing quantifying mechanisms responsible for the long term evolution of the aquifer. A non steady state 1D model has been developed which takes into account leaching, adsorption processes as well as radioactive filiation and α-recoil effect. Retardation coefficients have been calculated for uranium, thorium and radium. The aquifer is characterised by a double porosity, and the contribution of fracture and matrix porosity on the water/rock interaction processes has been estimated. (author)

  14. Behaviour and fate of nine recycled water trace organics during managed aquifer recharge in an aerobic aquifer.

    Science.gov (United States)

    Patterson, B M; Shackleton, M; Furness, A J; Bekele, E; Pearce, J; Linge, K L; Busetti, F; Spadek, T; Toze, S

    2011-03-25

    The fate of nine trace organic compounds was evaluated during a 12month large-scale laboratory column experiment. The columns were packed with aquifer sediment and evaluated under natural aerobic and artificial anaerobic geochemical conditions, to assess the potential for natural attenuation of these compounds during aquifer passage associated with managed aquifer recharge (MAR). The nine trace organic compounds were bisphenol A (BPA), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR), carbamazepine, oxazepam, iohexol and iodipamide. In the low organic carbon content Spearwood sediment, all trace organics were non-retarded with retardation coefficients between 1.0 and 1.2, indicating that these compounds would travel at near groundwater velocities within the aquifer. The natural aerobic geochemical conditions provided a suitable environment for the rapid degradation for BPA, E2, iohexol (half life aquifer geochemical conditions (half life >50days). Field-based validation experiments with carbamazepine and oxazepam also showed no degradation. If persistent trace organics are present in recycled waters at concentrations in excess of their intended use, natural attenuation during aquifer passage alone may not result in extracted water meeting regulatory requirements. Additional pre treatment of the recycled water would therefore be required. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  15. Alternative Fuels Data Center: Hybrid and Electric Vehicles Boom Coast to

    Science.gov (United States)

    Coast Hybrid and Electric Vehicles Boom Coast to Coast to someone by E-mail Share Alternative Fuels Data Center: Hybrid and Electric Vehicles Boom Coast to Coast on Facebook Tweet about Alternative Fuels Data Center: Hybrid and Electric Vehicles Boom Coast to Coast on Twitter Bookmark Alternative

  16. Ground-water levels in aquifers used for residential supply, Campton Township, Kane County, Illinois

    Science.gov (United States)

    Kay, Robert T.; Kraske, Kurt A.

    1996-01-01

    The U.S. Geological Survey, in cooperation with the Campton Township Board of Trustees, measured water levels in the aquifers used for residential supply in Campton Township, Kane County, Illinois. Aquifers used for residential supply are the shallow and deep aquifers in the glacial drift, composed of unconsolidated sand and gravels; the Alexandrian-Maquoketa aquifer, composed of dolomite and shale of the Alexandrian Series and the Maquoketa Group; the Galena-Platteville aquifer, composed of dolomite of the Platteville and Galena Groups; and the Ancell aquifer, composed of sandstones of the Glenwood Formation and the St. Peter Sanstone. Water-level altitudes in the shallow drift aquifers generally follow surface topography. Analysis of water-level data does not clearly indicate overutilization of these aquifers. Water-level altitudes in the deep drift aquifers decrease from west to east. Comparison of historical depth to water measurements with current (1995) measurements indicates large decreases in water levels in some areas. The deep drift aquifers may be overutilized at these locations. Water-level altitudes in the Alexandrian-Maquoketa aquifer generally decrease from west to east. The potentiometric surface of the aquifer follows the bedrock-surface topography in some locations. Localized low water-level altitudes and large decreases in water levels indicate the Alexandrian-Maquoketa aquifer is overutilized in several areas. Water-level altitudes in the wells finished in the Galena- Platteville aquifer vary by more than 300 feet. Large decreases in water levels in wells finished in the Galena-Platteville aquifer indicate the Galena-Platteville and Alexandrian-Maquoketa aquifers are overutilized in the northern part of the township. Water-level altitudes in the wells finished in the Ancell aquifer are also highly variable. There is no indication that the Ancell aquifer is overutilized.

  17. Development of Managed Aquifer Recharge in China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.; Zhou, Y.; Sun, X.; Wang, W.

    2014-10-01

    China has a long history in managed aquifer recharge (MAR). The historic development can be divided into 4 stages based on a summary of typical MAR projects. The first stage is MAR applied to agricultural production, the second is MAR applied to industrial production and alleviation of agricultural problems, the third is MAR applied to ecological protection and the increase in urban water supplies, and the fourth is multi-source MAR. In addition, geothermal reinjection and ground source heat pumps are also effective uses of MAR. Nevertheless, the MAR framework is defective, there is a lack of water quality studies, and the recharge rate of most projects is low. However, China has achieved a great effect on industrial and agricultural production, ecological protection, drinking water supplies and urban reclaimed water reuse, amongst others. But there are still many issues to be improved. A feasible, convenient and economic technique of MAR which fits local hydrogeological conditions needs to be developed and guidelines for both MARs and management regulations to ensure the successful running of MAR projects also need to be established. MAR will make a great difference to improving potable water quality, alleviating geological hazards, long distance water diversion, urban water supplies, agriculture irrigation, etc. (Author)

  18. DNAPL migration in a coastal plain aquifer

    International Nuclear Information System (INIS)

    DiGuiseppi, W.H.; Jung, A.D.

    1995-01-01

    Soil and ground water at the Dover Gas Light Superfund Site, a former manufactured gas plant (1859 to 1948), are contaminated with polynuclear aromatic hydrocarbons and volatile organic compounds. Contaminants of concern include light aromatics, such as benzene, toluene, ethylbenzene, and xylenes (BTEX), and heavy aromatics, including naphthalene, acenaphthylene, phenanthrene, and benzo(a)pyrene. Although ground-water contaminant levels are elevated near the site, only naphthalene and acenaphthylene are present within an order of magnitude of their solubility limits, indicating the possibility of dense non-aqueous phase liquids (DNAPL) in the subsurface. The unconfined Columbia Aquifer, which is characterized by interfingering and discontinuous sand, silt, and clay Coastal Plain deposits, overlies a clay aquitard at a depth of 60 feet. The ground water beneath the intermediate clay horizon exhibited little or no contamination, even immediately downgradient from the site. The relationship between the more permeable granular sand horizons and the less permeable interfingering clay zones controls the migration of both the aqueous-phase contamination and the DNAPL. A detailed horizontal and vertical characterization of the subsurface stratigraphy was critical to the accurate interpretation of the extent and magnitude of contamination and the identification and delineation of DNAPL zones

  19. Soil aquifer treatment using advanced primary effluent

    KAUST Repository

    Sharma, Saroj K.; Hussen, Mustefa; Amy, Gary L.

    2011-01-01

    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.

  20. Modeling contaminant plumes in fractured limestone aquifers

    DEFF Research Database (Denmark)

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

    Determining the fate and transport of contaminant plumes from contaminated sites in limestone aquifers is important because they are a major drinking water resource. This is challenging because they are often heavily fractured and contain chert layers and nodules, resulting in a complex transport...... model. The paper concludes with recommendations on how to identify and employ suitable models to advance the conceptual understanding and as decision support tools for risk assessment and the planning of remedial actions....... behavior. Improved conceptual models are needed for this type of site. Here conceptual models are developed by combining numerical models with field data. Several types of fracture flow and transport models are available for the modeling of contaminant transport in fractured media. These include...... 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...

  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. 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.

  3. The economics of aquifer storage recovery technology

    International Nuclear Information System (INIS)

    David, R.; Pyne, G.

    2014-01-01

    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)

  4. 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)

  5. Fertilizers mobilization in alluvial aquifer: laboratory experiments

    Science.gov (United States)

    Mastrocicco, M.; Colombani, N.; Palpacelli, S.

    2009-02-01

    In alluvial plains, intensive farming with conspicuous use of agrochemicals, can cause land pollution and groundwater contamination. In central Po River plain, paleo-channels are important links between arable lands and the underlaying aquifer, since the latter is often confined by clay sediments that act as a barrier against contaminants migration. Therefore, paleo-channels are recharge zones of particular interest that have to be protected from pollution as they are commonly used for water supply. This paper focuses on fertilizer mobilization next to a sand pit excavated in a paleo-channel near Ferrara (Italy). The problem is approached via batch test leaking and columns elution of alluvial sediments. Results from batch experiments showed fast increase in all major cations and anions, suggesting equilibrium control of dissolution reactions, limited availability of solid phases and geochemical homogeneity of samples. In column experiments, early elution and tailing of all ions breakthrough was recorded due to preferential flow paths. For sediments investigated in this study, dispersion, dilution and chemical reactions can reduce fertilizers at concentration below drinking standards in a reasonable time frame, provided fertilizer loading is halted or, at least, reduced. Thus, the definition of a corridor along paleo-channels is recommended to preserve groundwater quality.

  6. Submarine canyons off the Coromandel coast

    Digital Repository Service at National Institute of Oceanography (India)

    Varadachari, V.V.R.; Nair, R.R.; Murty, P.S.N.

    During the 26th Cruise of I.N.S. `KISTNA', a bathymetric survey was carried out in some detail off the Pondicherry coast. This survey has revealed the existence of three sets of distinctly separate canyons between Cuddalore and Palar River...

  7. Synthetic tsunamis along the Israeli coast.

    Science.gov (United States)

    Tobias, Joshua; Stiassnie, Michael

    2012-04-13

    The new mathematical model for tsunami evolution by Tobias & Stiassnie (Tobias & Stiassnie 2011 J. Geophys. Res. Oceans 116, C06026) is used to derive a synthetic tsunami database for the southern part of the Eastern Mediterranean coast. Information about coastal tsunami amplitudes, half-periods, currents and inundation levels is presented.

  8. The Kenya Coast in national perspective

    NARCIS (Netherlands)

    Meilink, H.A.; Hoorweg, J.; Foeken, D.W.J.; Obudho, R.A.

    2000-01-01

    This chapter provides a concise review of the process of regional development and the concomitant growing regional inequalities in Kenya. By focusing on Coast Province, it aims to verify statements which stress that the province has gradually moved to a marginal position in Kenyan society. Examining

  9. Coast redwood live crown and sapwood

    Science.gov (United States)

    John-Pascal Berrill; Jesse L. Deffress; Jessica M. Engle

    2012-01-01

    Understanding crown rise and sapwood taper will help meet management objectives such as producing long branch-free boles for clear wood and old-growth restoration, or producing sawlogs with a high proportion of heartwood. Coast redwood (Sequoia sempervirens) tree crown ratio data were collected 20 years after partial harvesting in a 65-year-old second growth stand....

  10. Statistical modeling of geopressured geothermal reservoirs

    Science.gov (United States)

    Ansari, Esmail; Hughes, Richard; White, Christopher D.

    2017-06-01

    Identifying attractive candidate reservoirs for producing geothermal energy requires predictive models. In this work, inspectional analysis and statistical modeling are used to create simple predictive models for a line drive design. Inspectional analysis on the partial differential equations governing this design yields a minimum number of fifteen dimensionless groups required to describe the physics of the system. These dimensionless groups are explained and confirmed using models with similar dimensionless groups but different dimensional parameters. This study models dimensionless production temperature and thermal recovery factor as the responses of a numerical model. These responses are obtained by a Box-Behnken experimental design. An uncertainty plot is used to segment the dimensionless time and develop a model for each segment. The important dimensionless numbers for each segment of the dimensionless time are identified using the Boosting method. These selected numbers are used in the regression models. The developed models are reduced to have a minimum number of predictors and interactions. The reduced final models are then presented and assessed using testing runs. Finally, applications of these models are offered. The presented workflow is generic and can be used to translate the output of a numerical simulator into simple predictive models in other research areas involving numerical simulation.

  11. Ground-water quality of the surficial aquifer system and the upper Floridan Aquifer, Ocala National Forest and Lake County, Florida, 1990-99

    Science.gov (United States)

    Adamski, J.C.; Knowles, Leel

    2001-01-01

    Data from 217 ground-water samples were statistically analyzed to assess the water quality of the surficial aquifer system and Upper Floridan aquifer in the Ocala National Forest and Lake County, Florida. Samples were collected from 49 wells tapping the surficial aquifer system, 141 wells tapping the Upper Floridan aquifer, and from 27 springs that discharge water from the Upper Floridan aquifer. A total of 136 samples was collected by the U.S. Geological Survey from 1995 through 1999. These data were supplemented with 81 samples collected by the St. Johns River Water Management District and Lake County Water Resources Management from 1990 through 1998. In general, the surficial aquifer system has low concentrations of total dissolved solids (median was 41 milligrams per liter) and major ions. Water quality of the surficial aquifer system, however, is not homogeneous throughout the study area. Concentrations of total dissolved solids, many major ions, and nutrients are greater in samples from Lake County outside the Ocala National Forest than in samples from within the Forest. These results indicate that the surficial aquifer system in Lake County outside the Ocala National Forest probably is being affected by agricultural and (or) urban land-use practices. High concentrations of dissolved oxygen (less than 0.1 to 8.2 milligrams per liter) in the surficial aquifer system underlying the Ocala National Forest indicate that the aquifer is readily recharged by precipitation and is susceptible to surface contamination. Concentrations of total dissolved solids were significantly greater in the Upper Floridan aquifer (median was 182 milligrams per liter) than in the surficial aquifer system. In general, water quality of the Upper Floridan aquifer was homogeneous, primarily being a calcium or calciummagnesium- bicarbonate water type. Near the St. Johns River, the water type of the Upper Floridan aquifer is sodium-chloride, corresponding to an increase in total dissolved

  12. Artificial Intelligence-Based Models for the Optimal and Sustainable Use of Groundwater in Coastal Aquifers

    Science.gov (United States)

    Sreekanth, J.; Datta, Bithin

    2011-07-01

    Overexploitation of the coastal aquifers results in saltwater intrusion. Once saltwater intrusion occurs, it involves huge cost and long-term remediation measures to remediate these contaminated aquifers. Hence, it is important to have strategies for the sustainable use of coastal aquifers. This study develops a methodology for the optimal management of saltwater intrusion prone aquifers. A linked simulation-optimization-based management strategy is developed. The methodology uses genetic-programming-based models for simulating the aquifer processes, which is then linked to a multi-objective genetic algorithm to obtain optimal management strategies in terms of groundwater extraction from potential well locations in the aquifer.

  13. Unconfined aquifer response to infiltration basins and shallow pump tests

    Science.gov (United States)

    Ostendorf, David W.; DeGroot, Don J.; Hinlein, Erich S.

    2007-05-01

    SummaryWe measure and model the unsteady, axisymmetric response of an unconfined aquifer to delayed, arbitrary recharge. Water table drainage follows the initial elastic aquifer response, as modeled for uniform, instantaneous recharge by Zlotnik and Ledder [Zlotnik, V., Ledder, G., 1992. Groundwater flow in a compressible unconfined aquifer with uniform circular recharge. Water Resources Research 28(6), 1619-1630] and delayed drainage by Moench [Moench, A.F., 1995. Combining the Neuman and Boulton models for flow to a well in an unconfined aquifer. Ground Water 33(3), 378-384]. We extend their analyses with a convolution integral that models the delayed response of an aquifer to infiltration from a circular infiltration basin. The basin routes the hydrograph to the water table with a decay constant dependent on a Brooks and Corey [Brooks, R.H., Corey, A.T., 1966. Properties of porous media affecting fluid flow. Journal of the Irrigation and Drainage Division ASCE 92(2), 61-88] unsaturated permeability exponent. The resulting closed form model approaches Neuman's [Neuman, S.P., 1972. Theory of flow in unconfined aquifers considering delayed response of the water table. Water Resources Research 8(4), 1031-1045] partially penetrating pump test equation for a small source radius, instantaneous, uniform drainage and a shallow screen section. Irrigation pump data at a well characterized part of the Plymouth-Carver Aquifer in southeastern Massachusetts calibrate the small source model, while infiltration data from the closed drainage system of State Route 25 calibrate the infiltration basin model. The calibrated permeability, elasticity, specific yield, and permeability exponent are plausible and consistent for the pump and infiltration data sets.

  14. The use of chemical and isotopic data as indicators of the origin of waters and dissolved salts in the Bambui calcareous aquifer (Bahia-Brazil)

    International Nuclear Information System (INIS)

    Siqueira, A.F.

    1978-10-01

    Samples of 25 wells located in the Bambui limestone aquifer in the region of Irece - Bahia, have been analised for the isotopic ratio 18 O/ 16 O and the major chemical species Ca, Mg, Na, K, Cl, SO 4 and bicarbonate. The oxygen-18 data have been found to range between -2,62/00(in a thousand) to -6,66/00(in a thousand) relative to the universal Standard Mean Ocean Water (SMOW) and are compared with the values of the precipitation in the localities of Jacobina and Lencois (meteorological stations nearby) and with the values of the groundwater in sedimentary basins in northeastern Brazil. The comparison suggests that aquifer system is recharged by precipitation originated in northeastern Brazil, instead of originating on coast of Bahia, east of the area. Furthermore, the waters in aquifer are not found homogenized, having widely varying 18 O and chemical composition and being of different ages. The strong correlation between the observations Ca, Mg, Na, Cl and TDS (total dissolved solids) suggests an aerosol origin of salts, not excluding the hypothesis of dissolution of rock, which concentrations. The comparison of characteristic ratios Mg/Ca, SO 4 /Cl and (Cl-Na)/Cl, a Piper diagrama and a dendrogram established by cluster analysis, indicates that the wells may be separated in to two groups according to the isotopic or geochemical environment to which they belong. These groups may represent the differents sources of salt proposed, one being from the limestone, the other having come from aerosols. (Author) [pt

  15. Using solute and heat tracers for aquifer characterization in a strongly heterogeneous alluvial aquifer

    Science.gov (United States)

    Sarris, Theo S.; Close, Murray; Abraham, Phillip

    2018-03-01

    A test using Rhodamine WT and heat as tracers, conducted over a 78 day period in a strongly heterogeneous alluvial aquifer, was used to evaluate the utility of the combined observation dataset for aquifer characterization. A highly parameterized model was inverted, with concentration and temperature time-series as calibration targets. Groundwater heads recorded during the experiment were boundary dependent and were ignored during the inversion process. The inverted model produced a high resolution depiction of the hydraulic conductivity and porosity fields. Statistical properties of these fields are in very good agreement with estimates from previous studies at the site. Spatially distributed sensitivity analysis suggests that both solute and heat transport were most sensitive to the hydraulic conductivity and porosity fields and less sensitive to dispersivity and thermal distribution factor, with sensitivity to porosity greatly reducing outside the monitored area. The issues of model over-parameterization and non-uniqueness are addressed through identifiability analysis. Longitudinal dispersivity and thermal distribution factor are highly identifiable, however spatially distributed parameters are only identifiable near the injection point. Temperature related density effects became observable for both heat and solute, as the temperature anomaly increased above 12 degrees centigrade, and affected down gradient propagation. Finally we demonstrate that high frequency and spatially dense temperature data cannot inform a dual porosity model in the absence of frequent solute concentration measurements.

  16. US Coast Guard Stations in Louisiana, Geographic NAD83, USCG [coast_guard_stations_USCG_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is is a point dataset for the locations and attributes of eight US Coast Guard stations in Louisiana. The attributes include name, address, latitude (NAD27),...

  17. Subtidal benthic macrofauna of the Mangalore Coast, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalakrishnan, T.C.; Nair, K.K.C.

    Subtidal macrobenthic fauna from the Mangalore Coast was studied from the shelf areas between the old Mangalore Port and Suratkal, covering an area of approximately 40 km sup(2). Benthic bivalves were the most abundant group, (36160/m sup(2...

  18. West Coast DA Event data - West Coast Toxic Pseudo-nitzschia bloom

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Beginning in the spring of 2015 the US West Coast began to experience the most wide-spread toxic Pseudo-nitzschia bloom to date, after approximately eight years...

  19. 75 FR 24482 - Fisheries Off West Coast States; West Coast Salmon Fisheries; 2010 Management Measures

    Science.gov (United States)

    2010-05-05

    ... West Coast Vancouver Island (WCVI) troll and sport fishery and 15 percent in Alaska's Southeast Alaska... Chinook recreational TAC for north of Cape Falcon (C.5). --Cape Alava to Queets River (La Push Subarea...

  20. 78 FR 3848 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

    Science.gov (United States)

    2013-01-17

    ... Rationalization Program; Emergency Rule Extension AGENCY: National Marine Fisheries Service (NMFS), National... Coast Groundfish Fishery Trawl Rationalization Program (program) regulations. This emergency rule... trawl rationalization program. Background on this rule was provided in the proposed rule, published on...

  1. California coast sablefish - Reproductive Life History Analysis of Sablefish Populations off the Washington and California Coasts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sablefish (Anoplopoma fimbria) have a wide distribution along the Pacific coast, extending from Baja California to Alaska, the Bering Sea and through to the eastern...

  2. Studies on sediment transport along Kerala Coast, south west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sajeev, R.; Chandramohan, P.; Josanto, V.; Sanakaranarayanan, V.N.

    Longshore sediment transport characteristics of the Kerala Coast have been examined to delineate various physical processes affecting the different coastal environments. Monthly averages of the daily LEO (Littoral Environmental Observation) data...

  3. Marine archaeological investigations along the Saurashtra coast, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh; Tripati, S.

    Utilization of the ocean resources on the Saurashtra coast is dating back to the Harappan period (3rd millennium BC) and evidences on the same have been recorded from various archaeological sites such as Lothal, Padri, Nageshwar and Bet Dwarka...

  4. Washington coast sablefish - Reproductive Life History Analysis of Sablefish Populations off the Washington and California Coasts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sablefish (Anoplopoma fimbria) have a wide distribution along the Pacific coast, extending from Baja California to Alaska, the Bering Sea and through to the eastern...

  5. Tsunami impacts on morphology of beaches along south Kerala coast, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rasheed, K.A.A.; Das, V.K.; Revichandran, C.; Vijayan, P.R.; Thottam, T.J.

    TSUNAMI IMPACTS ON MORPHOLOGY OF BEACHES ALONG SOUTH KERALA COAST, WEST COAST OF INDIA K. A. Abdul Rasheed *, V. Kesava Das, C. Revichandran, P. R. Vijayan and Tony. J. Thottam National Institute of Oceanography (NIO), Regional Centre (RC... large waves of height 11 to 11.5m in Kutch region (Pendse 1945). Most of the tsunamis are generated by the earthquake-initiated seabed displacements. Landslides (including underwater landslides), volcanic eruptions, impact of large objects (such...

  6. Heavy mineral occurrence off Hazira, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Mislankar, P.G.; Gujar, A.R.

    The occurrence of heavy mineral placers on the west coast of India are well known from Konkan and Malabar Coast. However, a geological and geophysical investigation (including echosounding and side scan sonar profiles and 7 samples) off Hazira...

  7. Occurrence of Porphyra vietnamensis (Bangiales, Rhodophyta) along the Goa coast

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.; Agadi, V.V.; Untawale, A.G.

    The occurrence of a red alga, Porphyra vietnamensis has been studied along the Goa Coast (west coast of India). The growth period was observed during the monsoon (July-October) and optimum growth was recorded during August, when temperature...

  8. Benthic fauna of southwest and southeast coasts of India

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, K.S.; Sheba, P.; Balasubramanian; Venugopal, P.; Sankaranarayanan, V.N.

    Benthos, sediments characteristics and organic matter content were studied along southwest and southeast coasts of India. Number of groups/species varied with the stations and also with the depths. Population density was very low in southeast coast...

  9. 75 FR 53667 - Space Coast Regional Innovation Cluster Competition

    Science.gov (United States)

    2010-09-01

    ... Coast Regional Innovation Cluster Competition AGENCY: Economic Development Administration (EDA... upcoming availability of funding for the Space Coast Regional Innovation Cluster (RIC) Competition under... economic development initiatives aligned with regional cluster and competitiveness analyses to sustain the...

  10. 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. © 2014 The Authors. Groundwater published by Wiley Periodicals, Inc. on behalf of National Ground Water Association.

  11. 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

  12. 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

  13. 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

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

    Science.gov (United States)

    Rodríguez, L.; Vives, L.; Gomez, A.

    2013-01-01

    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 the aquifer boundaries, except at the eastern boundary. On average

  15. A New Boundary for the High Plains - Ogallala Aquifer Complex

    Science.gov (United States)

    Haacker, E. M.; Nozari, S.; Kendall, A. D.

    2017-12-01

    In the semi-arid Great Plains, water is the key ingredient for crop growth: the difference between meager yields for many crops and an agricultural bonanza. The High Plains-Ogallala Aquifer complex (HPA) underlies 452,000 square kilometers of the region, and over 95% of water withdrawn from the aquifer is used for irrigation. Much of the HPA is being pumped unsustainably, and since the region is heavily reliant on this resource for its social and economic health, the High Plains has been a leader in groundwater management planning. However, the geographic boundary of the High Plains region fails to reflect the hydrogeological realities of the aquifer. The current boundary, recognizable from countless textbooks and news articles, is only slightly modified from a version from the 1980's, and largely follows the physiographic borders of the High Plains - defined by surface features such as escarpments and rivers - rather than the edges of water-bearing sediment sufficient for high-volume pumping. This is supported by three lines of evidence: hydrogeological observations from the original aquifer boundary determination; the extent of irrigated land, as estimated by MODIS-MIrAD data; and statistical estimates of saturated thickness, incorporating improved maps of the aquifer base and an additional 35 years of water table measurements. In this project, new maps of saturated thickness are used to create an updated aquifer boundary, which conforms with the standard definition of an aquifer as a package of sediment that yields enough water to be economically pumped. This has major implications for social and physical models, as well as water planning and estimates of sustainability for the HPA. Much of the area of the HPA that has been labeled `sustainable' based upon estimates of recharge relative to pumping estimates falls outside the updated aquifer boundary. In reality, the sustainably-pumped area of this updated aquifer boundary is far smaller—a fact that if more

  16. Toward an Economic Definition of Sustainable Yield for Coastal Aquifers

    Science.gov (United States)

    Jenson, J. W.; Habana, N. C.; Lander, M.

    2016-12-01

    The concept of aquifer sustainable yield has long been criticized, debated, and even disparaged among groundwater hydrologists, but policy-makers and professional water resource managers inevitably ask them for unequivocal answers to such questions as "What is the absolute maximum volume of water that could be sustainably withdrawn from this aquifer?" We submit that it is therefore incumbent upon hydrologists to develop and offer valid practical definitions of sustainable yield that can be usefully applied to given conditions and types of aquifers. In coastal aquifers, water quality—in terms of salinity—is affected by changes in the natural water budget and the volume rate of artificial extraction. In principle, one can identify a family of assay curves for a given aquifer, showing the specific relationships between the quantity and quality of the water extracted under given conditions of recharge. The concept of the assay curve, borrowed from the literature of natural-resource extraction economics, has to our knowledge not yet found its way into the literature of applied hydrology. The relationships between recharge, extraction, and water quality that define the assay curve can be determined empirically from sufficient observations of groundwater response to recharge and extraction and can be estimated from models that have been reliably history-matched ("calibrated") to such data. We thus propose a working definition of sustainable yield for coastal aquifers in terms of the capacity that ultimately could be achieved by an ideal production system, given what is known or can be assumed about the natural limiting conditions. Accordingly, we also offer an approach for defining an ideal production system for a given aquifer, and demonstrate how observational data and/or modeling results can be used to develop assay curves of quality vs. quantity extracted, which can serve as reliable predictive tools for engineers, managers, regulators, and policy

  17. 46 CFR 50.10-25 - Coast Guard Symbol.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Coast Guard Symbol. 50.10-25 Section 50.10-25 Shipping... Definition of Terms Used in This Subchapter § 50.10-25 Coast Guard Symbol. (a) The term Coast Guard Symbol... impression of the Coast Guard Symbol for stamping nameplates and specimens is shown in Figure 50.10-25(b...

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

    International Nuclear Information System (INIS)

    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. Isotopic and chemical investigations of quaternary aquifer in sinai peninsula

    International Nuclear Information System (INIS)

    Sadek, M.A.; Ahmed, M.A.; Awad, M.A.

    2001-01-01

    The present study has been conducted to investigate the renewal activity and mineralization potential of the quaternary aquifer in Sinai peninsula using environmental isotopes and hydrochemistry. The quaternary aquifer is vital for development processes as it has a wide extension and shallow water table. The total dissolved salts vary greatly from one location to another and range widely between 510-7060 mg/1, reflecting all categories from fresh to saline water. The change in salinity all over Sinai can be attributed to variations in the rate of evaporation. Leaching and dissolution of terrestrial salts during floods as well as the effects of sea spray and saline water intrusion. The main sources of groundwater recharge are the infiltration of Local precipitation and surface runoff as well as lateral flow through hydraulic connection with fractured aquifers. Snow melt also contributes to aquifer recharge in some areas in the central part of southern Sinai. The environmental stable isotopic contents of the ground water in the quaternary aquifer in Sinai reflect the isotopic composition of rain water from continental and east Mediterranean precipitation and monsonal air mass which comes from Indian ocean as well as the seepage of partly evaporated floodwater. The southern samples are more suitable for drinking and irrigation purposes due to its lower salinity and sodium hazard

  20. Laboratory evidence of MTBE biodegradation in Borden aquifer material

    Science.gov (United States)

    Schirmer, Mario; Butler, Barbara J.; Church, Clinton D.; Barker, James F.; Nadarajah, Nalina

    2003-02-01

    Mainly due to intrinsic biodegradation, monitored natural attenuation can be an effective and inexpensive remediation strategy at petroleum release sites. However, gasoline additives such as methyl tert-butyl ether (MTBE) can jeopardize this strategy because these compounds often degrade, if at all, at a slower rate than the collectively benzene, toluene, ethylbenzene and the xylene (BTEX) compounds. Investigation of whether a compound degrades under certain conditions, and at what rate, is therefore important to the assessment of the intrinsic remediation potential of aquifers. A natural gradient experiment with dissolved MTBE-containing gasoline in the shallow, aerobic sand aquifer at Canadian Forces Base (CFB) Borden (Ontario, Canada) from 1988 to 1996 suggested that biodegradation was the main cause of attenuation for MTBE within the aquifer. This laboratory study demonstrates biologically catalyzed MTBE degradation in Borden aquifer-like environments, and so supports the idea that attenuation due to biodegradation may have occurred in the natural gradient experiment. In an experiment with batch microcosms of aquifer material, three of the microcosms ultimately degraded MTBE to below detection, although this required more than 189 days (or >300 days in one case). Failure to detect the daughter product tert-butyl alcohol (TBA) in the field and the batch experiments could be because TBA was more readily degradable than MTBE under Borden conditions.

  1. 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.

  2. Geochemical Triggers of Arsenic Mobilization during Managed Aquifer Recharge.

    Science.gov (United States)

    Fakhreddine, Sarah; Dittmar, Jessica; Phipps, Don; Dadakis, Jason; Fendorf, Scott

    2015-07-07

    Mobilization of arsenic and other trace metal contaminants during managed aquifer recharge (MAR) poses a challenge to maintaining local groundwater quality and to ensuring the viability of aquifer storage and recovery techniques. Arsenic release from sediments into solution has occurred during purified recycled water recharge of shallow aquifers within Orange County, CA. Accordingly, we examine the geochemical processes controlling As desorption and mobilization from shallow, aerated sediments underlying MAR infiltration basins. Further, we conducted a series of batch and column experiments to evaluate recharge water chemistries that minimize the propensity of As desorption from the aquifer sediments. Within the shallow Orange County Groundwater Basin sediments, the divalent cations Ca(2+) and Mg(2+) are critical for limiting arsenic desorption; they promote As (as arsenate) adsorption to the phyllosilicate clay minerals of the aquifer. While native groundwater contains adequate concentrations of dissolved Ca(2+) and Mg(2+), these cations are not present at sufficient concentrations during recharge of highly purified recycled water. Subsequently, the absence of dissolved Ca(2+) and Mg(2+) displaces As from the sediments into solution. Increasing the dosages of common water treatment amendments including quicklime (Ca(OH)2) and dolomitic lime (CaO·MgO) provides recharge water with higher concentrations of Ca(2+) and Mg(2+) ions and subsequently decreases the release of As during infiltration.

  3. Aquifer restoration at uranium in situ leach sites

    International Nuclear Information System (INIS)

    Anastasi, F.S.; Williams, R.E.

    1985-01-01

    In situ mining of uranium involves injection of a leaching solution (lixiviant) into an ore-bearing aquifer. Frequently, the ground water in the mined aquifer is a domestic or livestock water supply. As the lixiviant migrates through the ore body, uranium and various associated elements such as arsenic, selenium, molybdenum, vanadium and radium-226 are mobilized in the ground water. Aquifer restoration after in situ mining is not fully understood. Several methods have been developed to restore mined aquifers to pre-mining (baseline) quality. Commonly used methods include ground water sweeping, clean water injection, and treatment by ion exchange and reverse osmosis technologies. Ammonium carbonate lixiviant was used at one RandD in situ mine. Attempts were made to restore the aquifer using a variety of methods. Efforts were successful in reducing concentrations of the majority of contaminants to baseline levels. Concentrations of certain parameters, however, remained at levels above baseline six months after restoration ceased. Relatively large quantities of ground water were processed in the restoration attempt considering the small size of the project (1.25 acre). More thorough characterization of the hydrogeology of the site may have enhanced the effectiveness of restoration and reduced potential environmental impacts associated with the project. This paper presents some of the findings of a research project conducted by the Mineral Resources Waste Management Team at the University of Idaho in Moscow, Idaho. Views contained herein do not reflect U.S. Nuclear Regulatory Commission policy

  4. Hydrogeologic characterization of a fractured granitic rock aquifer, Raymond, California

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Andrew J.B. [Univ. of California, Berkeley, CA (United States)

    1993-10-01

    The hydrogeologic properties of a shallow, fractured granitic rock aquifer in the foothills of the Sierra Nevada, California were investigated via the analysis of borehole geophysical logs and pumping tests. The drawdowns produced during these tests are not indicative of any simple conceptual aquifer model, and borehole logs show that the granite is intensely fractured. These observations are suggestive of a complex fracture-flow geometry which is extremely difficult to decipher. However, through the measurement of orientations of individual subsurface fractures from acoustic televiewer logs, and correlation between particular fractures and electrical resistivity and thermal-pulse flowmeter logs, it was found that the aquifer is, in general, comprised of two subhorizontal and nearly parallel zones of unloading fractures. Downhole flowmeter measurements taken in several wells provide further evidence for the inferred dual-layer structure of the aquifer, as well as yield quantitative measures of the contribution of flow from each zone. Analysis of drawdowns in pumped wells reveals that there are zones of relatively high transmissivity immediately around them. It was found that these properties, as well as a nearby zone of lower transmissivity, can account for their observed drawdowns. A numerical model was constructed to test whether these major heterogeneities could also account for the drawdowns in observation wells. This stepwise analysis of both the geophysical and hydrological data resulted in the formulation of a conceptual model of the aquifer which is consistent with observations, and which can account for its behavior when subjected to pumping.

  5. Evaluation of permeable fractures in rock aquifers

    Science.gov (United States)

    Bok Lee, Hang

    2015-04-01

    In this study, the practical usefulness and fundamental applicability of a self-potential (SP) method for identifying the permeable fractures were evaluated by a comparison of SP methods with other geophysical logging methods and hydraulic tests. At a 10 m-shallow borehole in the study site, the candidates of permeable fractures crossing the borehole were first determined by conventional geophysical methods such as an acoustic borehole televiwer, temperature, electrical conductivity and gamma-gamma loggings, which was compared to the analysis by the SP method. Constant pressure injection and recovery tests were conducted for verification of the hydraulic properties of the fractures identified by various logging methods. The acoustic borehole televiwer and gamma-gamma loggings detected the open space or weathering zone within the borehole, but they cannot prove the possibility of a groundwater flow through the detected fractures. The temperature and electrical conductivity loggings had limitations to detect the fractured zones where groundwater in the borehole flows out to the surrounding rock aquifers. Comparison of results from different methods showed that there is a best correlation between the distribution of hydraulic conductivity and the variation of the SP signals, and the SP logging can estimate accurately the hydraulic activity as well as the location of permeable fractures. Based on the results, the SP method is recommended for determining the hydraulically-active fractures rather than other conventional geophysical loggings. This self-potential method can be effectively applied in the initial stage of a site investigation which selects the optimal location and evaluates the hydrogeological property of fractures in target sites for the underground structure including the geothermal reservoir and radioactive waste disposal.

  6. Shallow Aquifer Methane Gas Source Assessment

    Science.gov (United States)

    Coffin, R. B.; Murgulet, D.; Rose, P. S.; Hay, R.

    2014-12-01

    Shale gas can contribute significantly to the world's energy demand. Hydraulic fracturing (fracking) on horizontal drill lines developed over the last 15 years makes formerly inaccessible hydrocarbons economically available. From 2000 to 2035 shale gas is predicted to rise from 1% to 46% of the total natural gas for the US. A vast energy resource is available in the United States. While there is a strong financial advantage to the application of fracking there is emerging concern about environmental impacts to groundwater and air quality from improper shale fracking operations. Elevated methane (CH4) concentrations have been observed in drinking water throughout the United States where there is active horizontal drilling. Horizontal drilling and hydraulic-fracturing can increase CH4 transport to aquifers, soil and the vadose zone. Seepage can also result from casing failure in older wells. However, there is strong evidence that elevated CH4 concentrations can be associated with topographic and hydrogeologic features, rather than shale-gas extraction processes. Carbon isotope geochemistry can be applied to study CH4source(s) in shallow vadose zone and groundwater systems. A preliminary TAMU-CC isotope data set from samples taken at different locations in southern Texas shows a wide range of CH4 signatures suggesting multiple sources of methane and carbon dioxide. These data are interpreted to distinguish regions with methane contributions from deep-sourced horizontal drilling versus shallow system microbial production. Development of a thorough environmental assessment using light isotope analysis can provide understanding of shallow anthropogenic versus natural CH4sources and assist in identifying regions that require remedial actions.

  7. Mobilization of uranium isotopes in Brazilian aquifers

    International Nuclear Information System (INIS)

    Bonotto, Daniel Marcos

    1994-01-01

    The uranium isotopes 234 U and 238 U have been extensively used to study geochemical problems, mainly related to the hydrological medium. Active dissolution of these isotopes is occurring in groundwaters from several aquifers at southeastern region of Brazil. The dissolved uranium concentration showed variability related to the rainwater infiltration with the U content of groundwaters increasing during wet periods. The amount of uranium mobilized during rainwater infiltration showed an inverse correlation with the thickness of unsaturated silty clay at Morro do Ferro area. The experimental data favour the possibility of formation of soluble complexes of U and dissolved organic compounds at Morro do Ferro area, and also some absorption of U by clays during rainwater infiltration. Enhanced 234 U/ 238 U activity ratios for dissolved uranium have been found and explained in terms of combined chemical etch and leach processes for groundwaters of the Pocos de Caldas alkaline complex. These processes are considered responsible for the bulk dissolution of rock matrix rather then alpha-recoil effects. Several direct correlations have been found for groundwaters of Agua da Prata, which supported the effectiveness of etch/lead mechanisms, for example, between 234 U/ 238 U activity ratio and dissolved solids, ionic strength, C O 2 partial pressure, 'traditional' index of base exchange and 'new' index of base exchange (involving the anion fluoride). A higher 234 U/ 238 U activity ratio was found to be directly related to a higher value of dissolution rate and a higher value of 222 Rn content was found to be related with a higher value of specific surface area. These relationships explained a good inverse logarithmic correlation between 234 U/ 238 U activity ratio and 222 Rn content of the spring waters of Aguas da Prata. (author)

  8. Influence of sea ice on Arctic coasts

    Science.gov (United States)

    Barnhart, K. R.; Kay, J. E.; Overeem, I.; Anderson, R. S.

    2017-12-01

    Coasts form the dynamic interface between the terrestrial and oceanic systems. In the Arctic, and in much of the world, the coast is a focal point for population, infrastructure, biodiversity, and ecosystem services. A key difference between Arctic and temperate coasts is the presence of sea ice. Changes in sea ice cover can influence the coast because (1) the length of the sea ice-free season controls the time over which nearshore water can interact with the land, and (2) the location of the sea ice edge controls the fetch over which storm winds can interact with open ocean water, which in turn governs nearshore water level and wave field. We first focus on the interaction of sea ice and ice-rich coasts. We combine satellite records of sea ice with a model for wind-driven storm surge and waves to estimate how changes in the sea ice-free season have impacted the nearshore hydrodynamic environment along Alaska's Beaufort Sea Coast for the period 1979-2012. This region has experienced some of the greatest changes in both sea ice cover and coastal erosion rates in the Arctic: the median length of the open-water season has expanded by 90 percent, while coastal erosion rates have more than doubled from 8.7 to 19 m yr-1. At Drew Point, NW winds increase shoreline water levels that control the incision of a submarine notch, the rate-limiting step of coastal retreat. The maximum water-level setup at Drew Point has increased consistently with increasing fetch. We extend our analysis to the entire Arctic using both satellite-based observations and global coupled climate model output from the Community Earth System Model Large Ensemble (CESM-LE) project. This 30-member ensemble employs a 1-degree version of the CESM-CAM5 historical forcing for the period 1920-2005, and RCP 8.5 forcing from 2005-2100. A control model run with constant pre-industrial (1850) forcing characterizes internal variability in a constant climate. Finally, we compare observations and model results to

  9. Southern right whales Eubalaena australis visit the coasts of ...

    African Journals Online (AJOL)

    spamer

    Counts and photographs of right whales Eubalaena australis taken on aerial surveys of the southern coast of. South Africa between ... of 0.08–2.89 km.h-1. Theodolite tracking of undisturbed groups of right whales from Cape Columbine produced ...... right whales on the coast of Argentina (Outer Coast) between 1971 and ...

  10. South Coast Air Quality Management District Truck Testing | Transportation

    Science.gov (United States)

    Research | NREL South Coast Air Quality Management District Truck Evaluation South Coast Air Quality Management District Truck Evaluation Photo of heavy-duty truck cab. Electric drayage truck Cargo Transportation project, conducted in partnership with the South Coast Air Quality Management

  11. Assessment of Managed Aquifer Recharge Site Suitability Using a GIS and Modeling.

    Science.gov (United States)

    Russo, Tess A; Fisher, Andrew T; Lockwood, Brian S

    2015-01-01

    We completed a two-step regional analysis of a coastal groundwater basin to (1) assess regional suitability for managed aquifer recharge (MAR), and (2) quantify the relative impact of MAR activities on groundwater levels and sea water intrusion. The first step comprised an analysis of surface and subsurface hydrologic properties and conditions, using a geographic information system (GIS). Surface and subsurface data coverages were compiled, georeferenced, reclassified, and integrated (including novel approaches for combining related datasets) to derive a spatial distribution of MAR suitability values. In the second step, results from the GIS analysis were used with a regional groundwater model to assess the hydrologic impact of potential MAR placement and operating scenarios. For the region evaluated in this study, the Pajaro Valley Groundwater Basin, California, GIS results suggest that about 7% (15 km2) of the basin may be highly suitable for MAR. Modeling suggests that simulated MAR projects placed near the coast help to reduce sea water intrusion more rapidly, but these projects also result in increased groundwater flows to the ocean. In contrast, projects placed farther inland result in more long-term reduction in sea water intrusion and less groundwater flowing to the ocean. This work shows how combined GIS analysis and modeling can assist with regional water supply planning, including evaluation of options for enhancing groundwater resources. © 2014, National Ground Water Association.

  12. Removal of geosmin and 2-methylisoborneol during managed aquifer recharge: Batch and column studies

    KAUST Repository

    Maeng, Sungkyu; Abel, Chol D T; Sharma, Saroj K.; Park, Nosuk; Amy, Gary L.

    2012-01-01

    Managed aquifer recharge is a robust barrier in the multi-barrier approach to supply safe drinking water. The removal performance of gesomin and 2-methylisoborneol through managed aquifer recharge was investigated using batch and column experiments

  13. Regional assessment of aquifers for thermal-energy storage. Volume 2: Regions 7 through 12

    Science.gov (United States)

    1981-06-01

    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 unglaciated central region, glaciated Appalachians, unglaciated Appalachians, coastal plain, Hawaii, and Alaska are discussed.

  14. 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

  15. Hydrogeology, Pesticide DRASTIC for the Intermediate Aquifer. Pesticide DRASTIC coverage for the Intermediate Aquifer System. Drastic maps are most useful as a generalized tool to assess regional potential aquifer vulnerability., Published in 1998, 1:24000 (1in=2000ft) scale, Florida Department of Environmental Protection (FDEP).

    Data.gov (United States)

    NSGIC State | GIS Inventory — Hydrogeology dataset current as of 1998. Pesticide DRASTIC for the Intermediate Aquifer. Pesticide DRASTIC coverage for the Intermediate Aquifer System. Drastic maps...

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

    International Nuclear Information System (INIS)

    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 Captureclose quotes model that has been used in the initial phases of designing a groundwater remediation system in the A and M Areas

  17. A Novel Analytical Solution for Estimating Aquifer Properties and Predicting Stream Depletion Rates by Pumping from a Horizontally Anisotropic Aquifer

    Science.gov (United States)

    Huang, Y.; Zhan, H.; Knappett, P.

    2017-12-01

    Past studies modeling stream-aquifer interactions commonly account for vertical anisotropy, but rarely address horizontal anisotropy, which does exist in certain geological settings. Horizontal anisotropy is impacted by sediment deposition rates, orientation of sediment particles and orientations of fractures etc. We hypothesize that horizontal anisotropy controls the volume of recharge a pumped aquifer captures from the river. To test this hypothesis, a new mathematical model was developed to describe the distribution of drawdown from stream-bank pumping with a well screened across a horizontally anisotropic, confined aquifer, laterally bounded by a river. This new model was used to determine four aquifer parameters including the magnitude and directions of major and minor principal transmissivities and storativity based on the observed drawdown-time curves within a minimum of three non-collinear observation wells. By comparing the aquifer parameters values estimated from drawdown data generated known values, the discrepancies of the major and minor transmissivities, horizontal anisotropy ratio, storativity and the direction of major transmissivity were 13.1, 8.8, 4, 0 and managers to exploit groundwater resource reasonably while protecting stream ecosystem.

  18. Effect of Groundwater Pumping on Seawater Intrusion in Coastal Aquifers

    Directory of Open Access Journals (Sweden)

    M.M. Sherif

    2002-06-01

    Full Text Available Many aquifers around the globe are located in coastal areas and are thus subjected to the seawater intrusion phenomenon. The growth of population in coastal areas and the conjugate increase in human, agricultural, and industrial activities have imposed an increasing demand for freshwater. This increase in water demand is often covered by extensive pumping of fresh groundwater, causing subsequent lowering of the water table (or piezometric head and upsetting the dynamic balance between freshwater and saline water bodies. The classical result of such a development is seawater intrusion. This paper presents a review for the seawater intrusion phenomenon in coastal aquifers. The effect of pumping activities on the seawater intrusion in the Nile Delta aquifer of Egypt is investigated. It was concluded that any additional pumping should be located in the middle Delta and avoided in the eastern and western sides of the Delta.

  19. Processes Affecting Groundwater Quality in the La Digue Aquifer, Seychelles

    Energy Technology Data Exchange (ETDEWEB)

    Alcindor, A. [Public Utilities Corporation, Victoria (Seychelles); Sacchi, E. [Dipartimento di Scienze della Terra e dell' ambiente, Universita di Pavia (Italy); Taigbenu, A. E. [University of the Witwatersrand, Johannesburg (South Africa)

    2013-07-15

    This paper presents the results obtained by the public utilities corporation (PUC), within the framework of an IAEA TC project, which aims to evaluate the potential of the la digue aquifer. Several monitoring activities and hydrochemical and isotopic surveys have been conducted. Results indicate the presence of brackish water at shallow depths, and low redox potentials, attesting to the presence of H{sub 2}S and heavy metals. Groundwater quality is affected by the concomitant presence of different adverse factors, namely aquifer characteristics, hydrogeology, and anthropogenic pressure. In addition, seawater penetrates the river course during high tides and infiltrates through the recharge area of the aquifer that is close to the actual pumping station. The positioning of non return high tide gates, an easy and low cost intervention, could enhance groundwater quality. The understanding of the main processes affecting groundwater quality helped in the identification of areas favourable for new wells, located at higher elevations. (author)

  20. 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.

  1. Onset of density-driven instabilities in fractured aquifers

    Science.gov (United States)

    Jafari Raad, Seyed Mostafa; Hassanzadeh, Hassan

    2018-04-01

    Linear stability analysis is conducted to study the onset of density-driven convection involved in solubility trapping of C O2 in fractured aquifers. The effect of physical properties of a fracture network on the stability of a diffusive boundary layer in a saturated fractured porous media is investigated using the dual porosity concept. Linear stability analysis results show that both fracture interporosity flow and fracture storativity play an important role in the stability behavior of the system. It is shown that a diffusive boundary layer under the gravity field in fractured porous media with lower fracture storativity and/or higher fracture interporosity flow coefficient is more stable. We present scaling relations for the onset of convective instability in fractured aquifers with single and variable matrix block size distribution. These findings improve our understanding of density-driven flow in fractured aquifers and are important in the estimation of potential storage capacity, risk assessment, and storage site characterization and screening.

  2. On the migration of uranium isotopes in sandstone aquifers

    International Nuclear Information System (INIS)

    Froehlich, K.; Gellermann, R.

    1982-01-01

    Measurements of natural 238 U and 234 U activity in groundwater of sandstone aquifers have been used to study the migration of these uranium isotopes. Regarding the uranium exchange between liquid phase and rock surface during migration, two different models were applied for evaluating the experimental results. Values of corresponding parameters (retardation factor K, removal rate R) reflecting different behaviour concerning this exchange were determined. For example, the values obtained for 238 U in a Triassic sandstone aquifer of the GDR are K = 8.6 x 10 6 and R = 1.3 x 10 -3 a -1 , respectively. It was found that, under the conditions of the sandstone aquifer concerned, the removal rate model is better suited for calculating uranium-isotope migration in groundwater. (author)

  3. Hydrology of aquifer systems in the Memphis area, Tennessee

    Science.gov (United States)

    Criner, James H.; Sun, P-C. P.; Nyman, Dale J.

    1964-01-01

    The Memphis area as described in .this report comprises about 1,300 square miles of the Mississippi embayment part of the Gulf Coastal Plain. The area is underlain by as much as 3,000 feet of sediments ranging in age from Cretaceous through Quaternary. In 1960, 150 mgd (million gallons per day) of water was pumped from the principal aquifers. Municipal pumpage accounted for almost half of this amount, and industrial pumpage a little more than half. About 90 percent of the water used in the area is derived from the '500-foot' sand, and most of the remainder is from the ?400-foot' sand; both sands are of Eocene age. A small amount of water for domestic use is pumped from the terrace deposits of Pliocene and Pleistocene age. Both the '500-foot' and the '1,400-foot' sands are artesian aquifers except in the southeastern part of the area; there the water level in wells in the '500-foot' sand is now below the overlying confining clay. Water levels in both aquifers have declined almost continuously since pumping began, but the rate of decline has increased rapidly since 1940. Water-level decline in the '1,400-foot' sand has been less pronounced since 1956. The cones of depression in both aquifers have expanded and deepened as a result of the annual increases in pumping, and an increase in hydraulic gradients has induced a greater flow of water into the area. Approximately 135 mgd entered the Memphis area through the '500-foot' sand aquifer in 1960, and, of this amount, 60 mgd originated as inflow from the east and about 75 mgd was derived from leakage from the terrace deposits, from the north, south, and west and from other sources. Of the water entering the '1,400-foot' sand, about 5 mgd was inflow from the east, and about half that amount was from each of the north, south, and west directions. The average rate of movement of water outside the area of heavy withdrawals is about 70 feet per year in the '500-foot' sand and about 40 feet per year in the '1,400-foot' sand

  4. Geothermal reservoir simulation of hot sedimentary aquifer system using FEFLOW®

    Science.gov (United States)

    Nur Hidayat, Hardi; Gala Permana, Maximillian

    2017-12-01

    The study presents the simulation of hot sedimentary aquifer for geothermal utilization. Hot sedimentary aquifer (HSA) is a conduction-dominated hydrothermal play type utilizing deep aquifer, which is heated by near normal heat flow. One of the examples of HSA is Bavarian Molasse Basin in South Germany. This system typically uses doublet wells: an injection and production well. The simulation was run for 3650 days of simulation time. The technical feasibility and performance are analysed in regards to the extracted energy from this concept. Several parameters are compared to determine the model performance. Parameters such as reservoir characteristics, temperature information and well information are defined. Several assumptions are also defined to simplify the simulation process. The main results of the simulation are heat period budget or total extracted heat energy, and heat rate budget or heat production rate. Qualitative approaches for sensitivity analysis are conducted by using five parameters in which assigned lower and higher value scenarios.

  5. 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.

  6. Calcite raft geochemistry as a hydrological proxy for Holocene aquifer conditions in Hoyo Negro and Ich Balam (Sac Actun Cave System), Quintana Roo, Mexico

    Science.gov (United States)

    Kovacs, Shawn E.; Reinhardt, Eduard G.; Chatters, James C.; Rissolo, Dominique; Schwarcz, Henry P.; Collins, Shawn V.; Kim, Sang-Tae; Nava Blank, Alberto; Luna Erreguerena, Pilar

    2017-11-01

    Two cores from calcite rafts deposits located in Cenote Ich Balam and Hoyo Negro were dated and analyzed for 87Sr/86Sr, δ18O, δ13C, Sr/Ca and Cl/Ca. The geochemical records show changing aquifer salinity spanning the last ∼ 8.5 cal kyrs BP and interrelationships with Holocene climate trends (wet and dry periods). During the wet mid-Holocene, the salinity of the meteoric Water Mass (WM; at 7.8-8.3 cal kyrs BP) was relatively high at 1.5-2.7 ppt and then became less saline (1.0-1.5 ppt) during the last ∼ 7000 yrs as climate became progressively drier. High salinity of the meteoric WM during the wet mid-Holocene is attributed to increased turbulent mixing between the meteoric and underlying marine WM. Increased precipitation, in terms of amount, frequency, and intensity (e.g. hurricanes) causes higher flow of meteoric water towards the coast and mixing at the halocline, a phenomenon recorded with recent instrumental monitoring of the aquifer. Conversely, during dry periods reduced precipitation and flow in the meteoric WM would result in lower salinity. Karst properties and Holocene sea-level rise also seem to have an effect on the aquifer. When the regionally extensive network of shallow cave passages (∼ 10-12 m water depth) are flooded at ∼ 8000 cal yrs BP, there is a rapid shift in salinity. This study demonstrates that calcite raft deposits can be used as paleo-environmental recorders documenting the effects of sea level and climate change on aquifer condition.

  7. 76 FR 81851 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery...

    Science.gov (United States)

    2011-12-29

    .... 101206604-1758-02] RIN 0648-BA55 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National...) to implement Amendment 16 to the Pacific Coast Salmon Fishery Management Plan for Commercial and...

  8. 76 FR 65673 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery...

    Science.gov (United States)

    2011-10-24

    .... 101206604-1620-01] RIN 0648-BA55 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National... implement Amendment 16 to the Pacific Coast Salmon Fishery Management Plan for Commercial and Recreational...

  9. 77 FR 75101 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery...

    Science.gov (United States)

    2012-12-19

    .... 120813333-2647-01] RIN 0648-BC28 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National.... SUMMARY: NMFS proposes regulations to implement Amendment 17 to the Pacific Coast Salmon Fishery...

  10. 78 FR 10557 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery...

    Science.gov (United States)

    2013-02-14

    .... 120813333-3107-02] RIN 0648-BC28 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National... implement Amendment 17 to the Pacific Coast Salmon Fishery Management Plan for Commercial and Recreational...

  11. Integrated and sustainable management of the shared aquifer systems in the Sahel region

    International Nuclear Information System (INIS)

    Edwerd, Mickel

    2012-01-01

    It highlights the project Justification, the long term objective, the specific objectives and the project implementation strategy. The countries which participate to this project are the following: Algeria, Benin, Burkina Faso, Cameroon, central African Republic, Chad, Gambia, Guinea-Bissau, Mali, Mauritania, Niger, Nigeria and Senegal. Regarding Aquifer System we have: Chad Basin, Liptako-Gourma Aquifer, Iullemeden Aquifer, Senegalo-Mauritanian Aquifer and Taoudeni/Tanezrouft Basin.

  12. Coasting beam theory applied to bunches

    International Nuclear Information System (INIS)

    Hereward, H.

    1975-01-01

    It is plausible to apply coasting beam criteria to bunches if one has short wavelength disturbances of the bunch and short memory wake fields, where short means short compared with a bunch length, for then one can argue that a piece of the bunch near the middle does not even know that the bunch has ends. Some other conditions probably required to validate this approach are discussed. The local Keil-Schnell criterion is derived from the local dispersion integral

  13. 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.

  14. Geothermal characterization of the coastal aquifer near Ravenna (Italy

    Directory of Open Access Journals (Sweden)

    M. Antonellini

    2012-12-01

    Full Text Available The coastal aquifer near Ravenna (Italy contains a large volume of groundwater (2,5x109 m3 whose quality has been compromised by sea-water intrusion. Today, the phreatic groundwater is mostly brackish with some lenses of freshwater floating on top of more saline water. This water, although impossible to use as drink-water or for irrigation, is still important to guarantee the health of wetland habitats and especially of the roman historical and coastal pine forests of Ravenna. With the objective of defining the flow pattern within the aquifer and the exchange between surface and ground water, we characterized the temperature distribution in the shallow subsurface by means of a dense network of piezometers. At the same time we had the opportunity to characterize the phreatic aquifer from the geothermal point of view, so that it could eventually be considered for use as a “low enthalpy” heat source. Heat pumps are able to extract heat during the winter and dissipate it during the summer. The temperature of the groundwater in the top layer of the aquifer (surficial zone is sensitive to the changes in atmospheric temperature throughout the year whereas the temperature of the deeper groundwater follows the geothermal gradient (geothermal zone. One of the scopes of the project is to discover at what depth is located the geothermal zone, so that the aquifer has a constant temperature throughout the year. A constant temperature is needed for storage of heat at low enthalpy. The thickness of the surficial zone and the temperature at the top of the geothermal zone are essentially related to land use, distance from the sea, sediment type, and amount of interaction between surface and groundwater. A knowledge of these factors allows to better exploit the geothermal potential of the aquifer when choosing the optimal placement of the heat pumps.

  15. Development of A Mississippi River Alluvial Aquifer Groundwater Model

    Science.gov (United States)

    Karakullukcu, R. E.; Tsai, F. T. C.; Bhatta, D.; Paudel, K.; Kao, S. C.

    2017-12-01

    The Mississippi River Alluvial Aquifer (MRAA) underlies the Mississippi River Valley of the northeastern Louisiana, extending from the north border of Louisiana and Arkansas to south central of Louisiana. The MRAA has direct contact with the Mississippi River. However, the interaction between the Mississippi River and the alluvial aquifer is largely unknown. The MRAA is the second most used groundwater source in Louisiana's aquifers with about 390 million gallons per day, which is about 25% of all groundwater withdrawals in Louisiana. MRAA is the major water source to agriculture in the northeastern Louisiana. The groundwater withdrawals from the MRAA increases annually for irrigation. High groundwater pumping has caused significant groundwater level decline and elevated salinity in the aquifer. Therefore, dealing with agricultural irrigation is the primary purpose for managing the MRAA. The main objective of this study is to develop a groundwater model as a tool for the MRAA groundwater management. To do so, a hydrostratigraphy model of the MRAA was constructed by using nearly 8,000 drillers' logs and electric logs collected from Louisiana Department of Natural Resources. The hydrostratigraphy model clearly shows that the Mississippi River cuts into the alluvial aquifer. A grid generation technique was developed to convert the hydrostratigraphy model into a MODFLOW model with 12 layers. A GIS-based method was used to estimate groundwater withdrawals for irrigation wells based on the crop location and acreage from the USDACropScape - Cropland Data Layer. Results from the Variable Infiltration Capacity (VIC) model were used to determine potential recharge. NHDPlusV2 data was used to determine water level for major streams for the MODFLOW River Package. The groundwater model was calibrated using groundwater data between 2004 and 2015 to estimate aquifer hydraulic conductivity, specific yield, specific storage, river conductance, and surficial recharge.

  16. Alien species on the coasts of Turkey

    Directory of Open Access Journals (Sweden)

    M.E. CINAR

    2005-12-01

    Full Text Available The compilation of data on alien species reported from the Turkish coasts yielded a total of 263 species belonging to 11 systematic groups, of which Mollusca had the highest number of species (85 species, followed by Crustacea (51, fishes (43 and phytobenthos (39. The Black Sea is represented by a total of 20 alien species, the Sea of Marmara by 48 species, the Aegean Sea by 98 species and the Levantine Sea by 202 species. The majority of aliens found in the Black Sea and the Sea of Marmara were transported via shipping, whereas the Levantine coast is extensively subjected to Lessepsian migration. Benthic habitats (soft and hard substrata comprise 76% of the total alien species and the pelagic environment is inhabited by thirty-nine species. Almost 50% of aliens collected from the Turkish coasts were found only at 0-10 m depth. Eight species occur at depths deeper than 100 m. The impacts of aliens on the benthic and pelagic ecosystems are presented.

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

    OpenAIRE

    Montoya, Modesto; Mamani, Enoc

    2014-01-01

    The 8 million inhabitants of the coastal city Lima are supplied with water from the Rimac and Chillon rivers and water wells in the Lima aquifer. The history of the Rimac River flow and static level of water in its wells have been correlated to calculate the residence time of water in the aquifer it is recharged by the Rimac River until it reaches a well located 12 km away in the Miraflores District near the sea. The relative abundance of H-2 and O-18 are used to identify the origins of the w...

  18. Isotopic hydrodynamic of the aquifer systems Jaruco and Aguacate, Cuba

    International Nuclear Information System (INIS)

    Moleiro Leon, L.F.; Guerra Oliva, M.G.; Maloszewski, P.; Arellano Acosta, D.M.

    2002-01-01

    An isotopic dispersive model is applied to the Jaruco and Aguacate karstic groundwater basins of Western Cuba. The best fit of the model was validated with stable ( 18 O and 2 H ) and radioactive ( 3 H) isotopes. Modeling showed an aquifer stratification in two basic levels with turnover times of three month to upper level and close to 100 years to the lower level. The last one mainly supplies the base flow of the Ojo de agua and Bello springs and therefore, controls the dry season exploitation yields of the aqueducts of El Gato and Bello. Model results introduces an important constraint in the exploitation of groundwater resource of both aquifer systems

  19. Estimating aquifer transmissivity from specific capacity using MATLAB.

    Science.gov (United States)

    McLin, Stephen G

    2005-01-01

    Historically, specific capacity information has been used to calculate aquifer transmissivity when pumping test data are unavailable. This paper presents a simple computer program written in the MATLAB programming language that estimates transmissivity from specific capacity data while correcting for aquifer partial penetration and well efficiency. The program graphically plots transmissivity as a function of these factors so that the user can visually estimate their relative importance in a particular application. The program is compatible with any computer operating system running MATLAB, including Windows, Macintosh OS, Linux, and Unix. Two simple examples illustrate program usage.

  20. Effects of a Changing Climate on Seasonal Variation in Natural Recharge of Unconfined Coastal Aquifers

    Science.gov (United States)

    Antonellini, Marco; Nella Mollema, Pauline

    2013-04-01

    Irregular rainfall patterns throughout the year result in the discontinuous natural recharge of coastal aquifers, which has an effect on the size of freshwater lenses present in sandy deposits. The thickness of the freshwater lenses is important in the context of farmland salinization and coastal ecosystems survival. This study presents numerical models that simulate continuous and discontinuous recharge in sandy coastal aquifers and the thickness of resulting fresh water lenses under current and future climate scenarios. Temperature data for the period 1960-1990 from LOCCLIM FAO and from the IPCC SRES A1b scenario for 2070-2100, have been used to calculate the potential evapotranspiration. Potential recharge was defined as the difference between the precipitation and potential evapotranspiration in twelve locations around the world: Ameland (The Netherlands), Auckland and Wellington (New Zealand), Hong Kong, Ravenna (Italy), Mekong (Vietnam), Mumbai (India), New Jersey (USA), Nile Delta (Egypt), Kobe and Tokyo (Japan), and Singapore. These locations have shallow coastal aquifers along low lying coasts and comparable aquifer structure, which is the result of similar sediment supply and deposition in the Holocene as well as by the sea level changes from the last ice age to the present time. Particular attention has been paid to temporal variations of natural recharge that can vary from continuous recharge throughout the year to discontinuous recharge. The most dramatic reduction in the magnitude of potential annual recharge by the end of this century will occur at lower latitudes (Mumbai, Singapore, Hong Kong and Mekong). The most pronounced change in length of the dry period occurs for Kobe (Japan) and Singapore even though the total annual amount of recharge remains practically the same. The Influence of variable recharge on the size of freshwater lenses surrounded by saline water is simulated with the SEAWAT model. Models where the recharge is applied

  1. Degradation of herbicides in shallow Danish aquifers - an integrated laboratory and field study

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen; Mills, M.; Aamand, J.

    2001-01-01

    Degradation of pesticides in aquifers has been evaluated based on a number of co-ordinated field and laboratory studies carried out in Danish aquifers. These studies included investigations of vertical and horizontal variability in degradation rates from the vadose zone to an aquifer, the effects...

  2. Characterization of the sediments overlying the Floridan aquifer system in Alachua County, Florida

    OpenAIRE

    Green, Richard; Duncan, Joel; Seal, Thomas; Weinberg, J. Michael; Rupert, Frank

    1989-01-01

    The primary purpose of this project is to attempt to improve the existing hydrogeologic information through lithologic and hydrogeologic characterizations of the sediments overlying the Floridan aquifer system in Alachua County. These sediments locally comprise both the intermediate aquifer system and associated confining beds and the surficial aquifer system. (PDF has 119 pages.)

  3. Identification of the microbes mediating Fe reduction in a deep saline aquifer and their influence during managed aquifer recharge.

    Science.gov (United States)

    Ko, Myoung-Soo; Cho, Kyungjin; Jeong, Dawoon; Lee, Seunghak

    2016-03-01

    In this study, indigenous microbes enabling Fe reduction under saline groundwater conditions were identified, and their potential contribution to Fe release from aquifer sediments during managed aquifer recharge (MAR) was evaluated. Sediment and groundwater samples were collected from a MAR feasibility test site in Korea, where adjacent river water will be injected into the confined aquifer. The residual groundwater had a high salinity over 26.0 psu, as well as strong reducing conditions (dissolved oxygen, DOaquifer were found to be Citrobacter sp. However, column experiments to simulate field operation scenarios indicated that additional Fe release would be limited during MAR, as the dominant microbial community in the sediment would shift from Citrobacter sp. to Pseudomonas sp. and Limnohabitans sp. as river water injection alters the pore water chemistry. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. 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

  5. Accounting for the Decreasing Reaction Potential of Heterogeneous Aquifers in a Stochastic Framework of Aquifer-Scale Reactive Transport

    Science.gov (United States)

    Loschko, Matthias; Wöhling, Thomas; Rudolph, David L.; Cirpka, Olaf A.

    2018-01-01

    Many groundwater contaminants react with components of the aquifer matrix, causing a depletion of the aquifer's reactivity with time. We discuss conceptual simplifications of reactive transport that allow the implementation of a decreasing reaction potential in reactive-transport simulations in chemically and hydraulically heterogeneous aquifers without relying on a fully explicit description. We replace spatial coordinates by travel-times and use the concept of relative reactivity, which represents the reaction-partner supply from the matrix relative to a reference. Microorganisms facilitating the reactions are not explicitly modeled. Solute mixing is neglected. Streamlines, obtained by particle tracking, are discretized in travel-time increments with variable content of reaction partners in the matrix. As exemplary reactive system, we consider aerobic respiration and denitrification with simplified reaction equations: Dissolved oxygen undergoes conditional zero-order decay, nitrate follows first-order decay, which is inhibited in the presence of dissolved oxygen. Both reactions deplete the bioavailable organic carbon of the matrix, which in turn determines the relative reactivity. These simplifications reduce the computational effort, facilitating stochastic simulations of reactive transport on the aquifer scale. In a one-dimensional test case with a more detailed description of the reactions, we derive a potential relationship between the bioavailable organic-carbon content and the relative reactivity. In a three-dimensional steady-state test case, we use the simplified model to calculate the decreasing denitrification potential of an artificial aquifer over 200 years in an ensemble of 200 members. We demonstrate that the uncertainty in predicting the nitrate breakthrough in a heterogeneous aquifer decreases with increasing scale of observation.

  6. A novel analytical solution for estimating aquifer properties within a horizontally anisotropic aquifer bounded by a stream

    Science.gov (United States)

    Huang, Yibin; Zhan, Hongbin; Knappett, Peter S. K.

    2018-04-01

    Past studies modeling stream-aquifer interaction commonly account for vertical anisotropy in hydraulic conductivity, but rarely address horizontal anisotropy, which may exist in certain sedimentary environments. If present, horizontal anisotropy will greatly impact stream depletion and the amount of recharge a pumped aquifer captures from the river. This scenario requires a different and somewhat more sophisticated mathematical approach to model and interpret pumping test results than previous models used to describe captured recharge from rivers. In this study, a new mathematical model is developed to describe the spatiotemporal distribution of drawdown from stream-bank pumping with a well screened across a horizontally anisotropic, confined aquifer, laterally bounded by a river. This new model is used to estimate four aquifer parameters including the magnitude and directions of major and minor principal transmissivities and storativity based on the observed drawdown-time curves within a minimum of three non-collinear observation wells. In order to approve the efficacy of the new model, a MATLAB script file is programmed to conduct a four-parameter inversion to estimate the four parameters of concern. By comparing the results of analytical and numerical inversions, the accuracy of estimated results from both inversions is acceptable, but the MATLAB program sometimes becomes problematic because of the difficulty of separating the local minima from the global minima. It appears that the new analytical model of this study is applicable and robust in estimating parameter values for a horizontally anisotropic aquifer laterally bounded by a stream. Besides that, the new model calculates stream depletion rate as a function of stream-bank pumping. Unique to horizontally anisotropic and homogeneous aquifers, the stream depletion rate at any given pumping rate depends closely on the horizontal anisotropy ratio and the direction of the principle transmissivities relative to

  7. Ground-water flow directions and estimation of aquifer hydraulic properties in the lower Great Miami River Buried Valley aquifer system, Hamilton Area, Ohio

    Science.gov (United States)

    Sheets, Rodney A.; Bossenbroek, Karen E.

    2005-01-01

    The Great Miami River Buried Valley Aquifer System is one of the most productive sources of potable water in the Midwest, yielding as much as 3,000 gallons per minute to wells. Many water-supply wells tapping this aquifer system are purposely placed near rivers to take advantage of induced infiltration from the rivers. The City of Hamilton's North Well Field consists of 10 wells near the Great Miami River, all completed in the lower Great Miami River Buried Valley Aquifer System. A well-drilling program and a multiple-well aquifer test were done to investigate ground-water flow directions and to estimate aquifer hydraulic properties in the lower part of the Great Miami River Buried Valley Aquifer System. Descriptions of lithology from 10 well borings indicate varying amounts and thickness of clay or till, and therefore, varying levels of potential aquifer confinement. Borings also indicate that the aquifer properties can change dramatically over relatively short distances. Grain-size analyses indicate an average bulk hydraulic conductivity value of aquifer materials of 240 feet per day; the geometric mean of hydraulic conductivity values of aquifer material was 89 feet per day. Median grain sizes of aquifer material and clay units were 1.3 millimeters and 0.1 millimeters, respectively. Water levels in the Hamilton North Well Field are affected by stream stage in the Great Miami River and barometric pressure. Bank storage in response to stream stage is evident. Results from a multiple-well aquifer test at the well field indicate, as do the lithologic descriptions, that the aquifer is semiconfined in some areas and unconfined in others. Transmissivity and storage coefficient of the semiconfined part of the aquifer were 50,000 feet squared per day and 5x10-4, respectively. The average hydraulic conductivity (450 feet per day) based on the aquifer test is reasonable for glacial outwash but is higher than calculated from grain-size analyses, implying a scale effect

  8. Hydrogeologic and Hydraulic Characterization of the Surficial Aquifer System, and Origin of High Salinity Groundwater, Palm Beach County, Florida

    Science.gov (United States)

    Reese, Ronald S.; Wacker, Michael A.

    2009-01-01

    ) and highest transmissivity in coastal areas. Zone 2, the most transmissive and extensive zone, is thickest (80 feet or more) and most transmissive in the inland eastern areas near Florida's Turnpike. In this area, zone 1 is absent, and the semiconfining unit above zone 2 extends to the land surface with a thickness commonly ranging from 50 to 100 feet. The thickness of zone 2 decreases to zero in most wells near the coast. Zone 3 attains its greatest thickness (100 feet or more) in the southwestern and south-central areas; zone 3 is equivalent to the gray limestone aquifer. The distribution of transmissivity was mapped by zone; however, zones 2 and 3 were commonly combined in aquifer tests. Maximum transmissivities for zone 1, zones 2 and 3, and zone 3 were 90,000, 180,000, and 70,000 ft2/d (feet-squared per day), respectively. The northern extent of the area with transmissivity greater than 50,000 ft2/d for zones 2 and 3 in the inland northeastern area along Florida's Turnpike has not been defined based on available data and could extend 5 to 10 miles farther north than mapped. Based on the thickness of zone 2 and a limited number of aquifer tests, a large area of zone 2 with transmissivity greater than 10,000 ft2/d, and possibly as much as 30,000 ft2/d, extends to the west across Water Conservation Area 1 from the inland southeastern area into the south-central area and some of the southwestern area. In contrast to the Biscayne aquifer present to the south of Palm Beach County, zones 2 and 3 are interpreted to be present principally in the Tamiami Formation and are commonly overlain by a thick semiconfining unit of moderate permeability. These zones have been referred to as the 'Turnpike' aquifer in the inland eastern areas of Palm Beach County, and the extent of greatest thickness and transmissivity follows, or is adjacent to, Florida's Turnpike. Where it is thick and transmissive, zone 1 may be considered equivalent to the Biscayne aquifer. Areas

  9. Quality of Waters of Aquifer Webs of Biskra Region | Bouchemal ...

    African Journals Online (AJOL)

    Controlling the quality of water distributed together with sound resource management is a factor of economic and social development. Also, the chemistry and knowledge of geological and hydrogeological aquifer, the object of this work, we identify the water quality examined through physical-chemical parameters. The study ...

  10. 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

  11. 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...

  12. GROUND WATER ISSUE: STEAM INJECTION FOR SOIL AND AQUIFER REMEDIATION

    Science.gov (United States)

    The purpose of this Issue Paper is to provide to those involved in assessing remediation technologies for specific sites basic technical information on the use of steam injection for the remediation of soils and aquifers that are contaminated by volatile or semivolatile organic c...

  13. 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.

  14. Arsenic levels in groundwater aquifer of the Neoplanta source area ...

    African Journals Online (AJOL)

    As part of a survey on the groundwater aquifer at the Neoplanta source site, standard laboratory analysis of water quality and an electromagnetic geophysical method were used for long-term quantitative and qualitative monitoring of arsenic levels. This study presents only the results of research conducted in the ...

  15. Quality assessment of groundwater from shallow aquifers in Hong ...

    African Journals Online (AJOL)

    Quality assessment of groundwater from shallow aquifers in Hong area, Adamawa state, northeastern Nigeria. ... The high content of fluoride and iron in the groundwater may have contributed to the high EC and TDS especially during the rainy season when the rate of leaching and infiltration is high. Keywords: Quality ...

  16. 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.

  17. 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

  18. Assessing the sustainable application of Aquifer Thermal Energy Storage

    NARCIS (Netherlands)

    Jaxa-Rozen, M.; Bloemendal, J.M.; Rostampour Samarin, Vahab; Kwakkel, J.H.

    2016-01-01

    Aquifer Thermal Energy Storage (ATES) can yield significant reductions in the energy use and greenhouse gas (GHG) emissions of larger buildings, and the use of these systems has been rapidly growing in Europe – especially in the Netherlands, where over 3000 systems are currently active in urban

  19. Water budget of the Calera Aquifer in Zacatecas, Mexico

    Science.gov (United States)

    In the Calera Aquifer Region of the State of Zacatecas, Mexico, limited rainfall and low agricultural water use efficiency in combination with fast growing industrial and urban water demand are contributing to groundwater depletion at an unsustainable rate. Limited data and planning tools were avail...

  20. 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

  1. Water Decisions for Sustainability of the Arbuckle-Simpson Aquifer

    Science.gov (United States)

    Lazrus, H.; Mcpherson, R. A.; Morss, R. E.; PaiMazumder, D.; Silvis, V.; Towler, E.

    2012-12-01

    The Arbuckle-Simpson Aquifer in south-central Oklahoma, situated in the heart of the Chickasaw Nation, is the state's only sole-source groundwater basin and sustains the Blue River, the state's only freeflowing river. The recent comprehensive hydrological studies of the aquifer indicate the need for sustainable management of the amount of water extracted. However, the question of how to deal with that management in the face of increasing drought vulnerability, diverse demands, and climate variability and change remains. Water management carries a further imperative to be inclusive of tribal and non-tribal interests. To address these issues, this interdisciplinary project takes an integrated approach to understanding risk perceptions and water decisions for sustainability of the Arbuckle-Simpson Aquifer. Our interdisciplinary research asks: How do stakeholders in the Arbuckle-Simpson Aquifer perceive drought risks across weather and climate scales, and how do these perceptions guide water management decisions given (i) diverse cultural beliefs, (ii) valued hydrologic services, (iii) past drought experience, and (iv) uncertainties in future projection of precipitation and drought? We will use ethnographic methods to diagnose how cultural values and beliefs inform risk perceptions, and how this in turn guides decision making or ignites conflict across different sectors and stakeholder groups. Further, the characterization of drought risk will be examined in the context of historic meteorological and hydrologic events, as well as climate variability and change. This will identify which risks are prioritized, and under what conditions, in regional decision making or water-related conflicts.

  2. Saltwater Intrusion Appraisal of Shallow Aquifer in Burutu Area of ...

    African Journals Online (AJOL)

    ADOWIE PERE

    is not caused by saltwater intrusion rather by iron which cannot be separately distinguished from groundwater by ... The sand and gravels forms the aquifer in the. Formation and are .... K.S; Soulios, G; Pliakas, F; Tsokas, G ( 2016). Seawater ...

  3. hydrogeological caracterization and modeling of the aquifer of oued ...

    African Journals Online (AJOL)

    K. Baba-Hamed

    1 janv. 2018 ... Journal of Fundamental and Applied Sciences is licensed under a Creative Commons Attribution-NonCommercial 4.0. International License. Libraries Resource Directory. We are listed under Research Associations category. HYDROGEOLOGICAL CARACTERIZATION AND MODELING OF THE AQUIFER.

  4. Review: The Yucatán Peninsula karst aquifer, Mexico

    DEFF Research Database (Denmark)

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

    2011-01-01

    in the vicinity of the North American/Caribbean plate boundary and has been reshaped by a series of tectonic events over its long geologic history. At the end of the Cretaceous period, the Yucatán Peninsula was hit by a large asteroid, which formed the Chicxulub impact crater. The Yucatán Peninsula karst aquifer...

  5. A newly developed borehole flowmeter technology for heterogeneous aquifers

    International Nuclear Information System (INIS)

    Young, S.C.

    1990-01-01

    Extensive borehole flowmeter tests were performed at 37 fully-screened wells on a one-hectare test site to characterize the three-dimensional hydraulic conductivity field of an alluvial aquifer with a σ lnK of 4.7. During the site investigations, several major advancements with respect to borehole flowmeter technology were developed. The milestones included: (1) the development of a field-durable electromagnetic borehole flowmeter with a lower detection limit of 0.1 l/min; (2) the realization of the importance of the pumping rate with respect to the calculated value for the depth-averaged hydraulic conductivity; and (3) an evaluation of alternative methods for calculating the depth-averaged hydraulic conductivity. The predicted three-dimensional hydraulic conductivity field was compared to the results of 10 small-scale (3 to 7 m) tracer tests, information about the depositional history of the aquifer, and the results of three large-scale aquifer tests. The hydraulic conductivity data predict the major features of the tracer breakthrough curves, maps the outline of a former river meander in an aerial photograph, and leads to a geometric mean consistent with the average hydraulic conductivity of the aquifer. (Author) (14 refs., 15 figs., 2 tabs.)

  6. Determination of hydraulic characteristics of an aquifer capacity from ...

    African Journals Online (AJOL)

    Constant rate, single well pumping tests were conducted using boreholes located in four communities in the study area with the aim of determining the aquifer hydraulic properties using the Cooper Jacob method. Fractured shales yielded groundwater into the wells whose depths ranged from 26 to 35m while the static water ...

  7. Basement and alluvial aquifers of Malawi: An overview of ...

    African Journals Online (AJOL)

    Elizabeth B Mapoma

    2014-02-17

    Feb 17, 2014 ... Rowland HAL, Gault AG, Lythgoe P, Polya DA (2008) Geochemistry of aquifer sediments and arsenic-rich groundwaters from Kandal. Province, Cambodia. Appl. Geochem. 23: 3029–3046. Sajidu SM, Masumbu FFF, Fabiano E, Ngongondo C (2007). Drinking water quality and identification of fluoritic areas ...

  8. Determining hydraulic parameters of a karst aquifer using unique ...

    African Journals Online (AJOL)

    Although karst aquifers constitute some of the most important water resources worldwide, generally accepted methods for reliably characterising their hydraulic properties are still elusive. This paper aims at contributing to the discussion by a first-ever attempt to utilise various sets of unique historical data derived from ...

  9. Hydrofracturing water boreholes in hard rock aquifers in Scotland

    CSIR Research Space (South Africa)

    Cobbing, J

    2007-01-01

    Full Text Available rural areas of the UK, low-productivity aquifers are an important resource for small public water supplies. Where a borehole in low-productivity crystalline rocks proves too low yielding for its designed purpose, hydrofracturing is a cost-effective means...

  10. lithologic characterisation of the basement aquifers of awe and ...

    African Journals Online (AJOL)

    Global Journal

    resistivity exceeded 3000 ohm-m, then the bedrock is fresh and prospect for water is low (Olayinka and. Olorunfemi, 1992; Olorunfemi and Olorunniwo, 1990). Groundwater zones are found in the weathered and fractured zones in basement areas. In Ibarapa area of SW, Nigeria the associated fractured bedrock aquifers.

  11. Aquifer characteristics and groundwater recharge pattern in a typical ...

    African Journals Online (AJOL)

    EJIRO

    method in the delineation of bedrock structures, depth to possible aquifer units and to ... makes for susceptibility to surface contaminants; and (iii) ... regional tectonic setting which are critical to identifying favourable ... Data acquisition and processing. Thirty four ... The VES analysis shows a minimum of three and a maximum ...

  12. 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

  13. Combination of aquifer thermal energy storage and enhanced bioremediation

    NARCIS (Netherlands)

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

    2018-01-01

    Interest in the combination concept of aquifer thermal energy storage (ATES) and enhanced bioremediation has recently risen due to the demand for both renewable energy technology and sustainable groundwater management in urban areas. However, the impact of enhanced bioremediation on ATES is not

  14. Characterization of an island aquifer from tidal response

    Science.gov (United States)

    Banerjee, Pallavi; Sarwade, Deepak; Singh, V. S.

    2008-08-01

    Growing demand for potable water for various needs has lead to indiscriminate exploitation of groundwater resources, particularly, in the terrain where surface water resources are negligible. One such area is an island where groundwater is the only source of fresh water. Groundwater is the prime source of fresh water on most of the atolls in the world. Groundwater on these islands is in the form of thin fragile floating lens and is often vulnerable to overexploitation, draught, tidal waves, tsunami and cyclone resulting in seawater ingress. Sustainable development of this meager source of fresh groundwater for a longer time becomes a more difficult task on small atolls with a large population depending on this vital resource. To develop a sustainable management scheme and identify the vulnerable part of aquifer, characterization of the aquifer system on islands is imperative. Groundwater on an atoll is extremely vulnerable to seawater mixing through natural as well as human activities. One such natural process is the tides of the ocean. The response of sea tide to the water table on the island offers valuable data as well as cost-effective means to characterize an aquifer system. Such characterization is vital for the management of groundwater resources on an atoll. The obtained results have compared well with the parameters obtained through a conventional pumping test. Therefore, the use of tidal response to the water table, which can easily be recorded, provides a rapid and cost-effective means to characterization of the aquifer system on the island.

  15. Trench infiltration for managed aquifer recharge to permeable bedrock

    Science.gov (United States)

    Heilweil, V.M.; Watt, D.E.

    2011-01-01

    Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge in southwestern Utah have recently been implemented to meet growth-related water demands. This paper reports on a new cost-effective surface-infiltration technique utilizing trenches for enhancing managed aquifer recharge to permeable bedrock. A 48-day infiltration trench experiment on outcropping Navajo Sandstone was conducted to evaluate this alternative surface-spreading artificial recharge method. Final infiltration rates through the bottom of the trench were about 0.5 m/day. These infiltration rates were an order of magnitude higher than rates from a previous surface-spreading experiment at the same site. The higher rates were likely caused by a combination of factors including the removal of lower permeability soil and surficial caliche deposits, access to open vertical sandstone fractures, a reduction in physical clogging associated with silt and biofilm layers, minimizing viscosity effects by maintaining isothermal conditions, minimizing chemical clogging caused by carbonate mineral precipitation associated with algal photosynthesis, and diminished gas clogging associated with trapped air and biogenic gases. This pilot study illustrates the viability of trench infiltration for enhancing surface spreading of managed aquifer recharge to permeable bedrock. ?? 2010.

  16. Hydrogeological modelling of the Atlantis aquifer for management ...

    African Journals Online (AJOL)

    The Atlantis Water Supply Scheme (AWSS, Western Cape, South Africa) has been in operation for about 40 years as a means to supply and augment drinking water to the town of Atlantis via managed aquifer recharge (MAR). In this study, the numerical model MODFLOW for groundwater flow and contaminant transport was ...

  17. Relationship of regional water quality to aquifer thermal energy storage

    International Nuclear Information System (INIS)

    Allen, R.D.; Raymond, J.R.

    1990-01-01

    Aquifer thermal energy storage (ATES) involves injection and withdrawal of temperature-conditioned water into and from a permeable water-bearing formation. The groundwater quality and associated geological characteristics were assessed as they may affect the feasibility of ATES system development in any hydrologic region. Seven physical and chemical mechanisms may decrease system efficiency: particulate plugging, chemical precipitation, clay mineral dispersion, piping corrosion, aquifer disaggregation, mineral oxidation, and the proliferation of biota. Factors affecting groundwater quality are pressure, temperature, pH, ion exchange, evaporation/transpiration, and commingling with diverse waters. Modeling with the MINTEQ code showed three potential reactions: precipitation of calcium carbonate at raised temperatures; solution of silica at raised temperature followed by precipitation at reduced temperatures; and oxidation/precipitation of iron compounds. Low concentrations of solutes are generally favorable for ATES. Near-surface waters in high precipitation regions are low in salinity. Groundwater recharged from fresh surface waters also has reduced salinity. Rocks least likely to react with groundwater are siliceous sandstones, regoliths, and metamorphic rocks. On the basis of known aquifer hydrology, ten US water resource regions are candidates for selected exploration and development, all characterized by extensive silica-rich aquifers

  18. Copper and zinc distribution coefficients for sandy aquifer materials

    DEFF Research Database (Denmark)

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

    2000-01-01

    Distribution coe�cients (Kd) were measured for copper (Cu) and zinc (Zn) in laboratory batch experiments for 17 sandy aquifer materials at environmentally relevant solute concentrations (Cu: 5±300 mg/l, Zn: 20±3100 mg/l). The Kd values ranged two to three orders of magnitude (Cu: 70±10,800 l/ kg...

  19. Mapping Greenland's Firn Aquifer using L-band Microwave Radiometry

    Science.gov (United States)

    Miller, J.; Bringer, A.; Jezek, K. C.; Johnson, J. T.; Scambos, T. A.; Long, D. G.

    2016-12-01

    Greenland's recently discovered firn aquifer is one of the most interesting, yet still mysterious, components of the ice sheet system. Many open questions remain regarding timescales of refreezing and/or englacial drainage of liquid meltwater, and the connections of firn aquifers to the subglacial hydrological system. If liquid meltwater production at the surface of the Greenland ice sheet continues to increase, subsequent increases in the volume of mobile liquid meltwater retained within Greenland's firn aquifer may increase the possibility of crevasse-deepening via hydrofracture. Hydrofracture is an important component of supraglacial lake drainage leading to at least temporary accelerated flow velocities and ice sheet mass balance changes. Firn aquifers may also support hydrofracture-induced drainage and thus are potentially capable of significantly influencing ice sheet mass balance and sea level rise. Spaceborne L-band microwave radiometers provide an innovative tool for ice-sheet wide mapping of the spatiotemporal variability of Greenland's firn aquifer. Both refreezing and englacial drainage may be observable given the sensitivity of the microwave response to the upper surface of liquid meltwater retained within snow and firn pore space as well as the ability of L band instruments to probe the ice sheet from the surface to the firn-ice transition at pore close-off depth. Here we combine L-band (1.4 GHz) brightness temperature observations from multiple sources to demonstrate the potential of mapping firn aquifers on ice sheets using L-band microwave radiometry. Data sources include the interferometric MIRAS instrument aboard ESA's Soil Moisture and Ocean Salinity (SMOS) satellite mission and the radiometer aboard NASA's Soil Moisture Active Passive (SMAP) satellite mission. We will also present mulit-frequency L-band brightness temperature data (0.5-2 GHz) that will be collected over several firn aquifer areas on the Greenland ice sheet by the Ohio State

  20. Hydrochemical processes in a shallow coal seam gas aquifer and its overlying stream–alluvial system: implications for recharge and inter-aquifer connectivity

    International Nuclear Information System (INIS)

    Duvert, Clément; Raiber, Matthias; Owen, Daniel D.R.; Cendón, Dioni I.; Batiot-Guilhe, Christelle; Cox, Malcolm E.

    2015-01-01

    Highlights: • Major ions and isotopes used to study inter-aquifer mixing in a shallow CSG setting. • Considerable heterogeneity in the water composition of the coal-bearing aquifer. • Rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks. • Potential mixing between the coal-bearing aquifer and downstream alluvial aquifer. • Need to consider the seasonal influences on inter-aquifer mixing in CSG settings. - Abstract: In areas of potential coal seam gas (CSG) development, understanding interactions between coal-bearing strata and adjacent aquifers and streams is of highest importance, particularly where CSG formations occur at shallow depth. This study tests a combination of hydrochemical and isotopic tracers to investigate the transient nature of hydrochemical processes, inter-aquifer mixing and recharge in a catchment where the coal-bearing aquifer is in direct contact with the alluvial aquifer and surface drainage network. A strong connection was observed between the main stream and underlying alluvium, marked by a similar evolution from fresh Ca–Mg–HCO 3 waters in the headwaters towards brackish Ca–Na–Cl composition near the outlet of the catchment, driven by evaporation and transpiration. In the coal-bearing aquifer, by contrast, considerable site-to-site variations were observed, although waters generally had a Na–HCO 3 –Cl facies and high residual alkalinity values. Increased salinity was controlled by several coexisting processes, including transpiration by plants, mineral weathering and possibly degradation of coal organic matter. Longer residence times and relatively enriched carbon isotopic signatures of the downstream alluvial waters were suggestive of potential interactions with the shallow coal-bearing aquifer. The examination of temporal variations in deuterium excess enabled detection of rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks, particularly at the catchment

  1. Summary of hydrologic testing of the Floridan aquifer system at Fort Stewart, coastal Georgia, 2009-2010

    Science.gov (United States)

    Gonthier, Gerald J.

    2011-01-01

    Two test wells were completed at Fort Stewart, coastal Georgia, to investigate the potential for using the Lower Floridan aquifer as a source of water to satisfy anticipated, increased water needs. The U.S. Geological Survey, in cooperation with the U.S. Department of the Army, completed hydrologic testing of the Floridan aquifer system at the study site, including flowmeter surveys, slug tests, and 24- and 72-hour aquifer tests by mid-March 2010. Analytical approaches and model simulation were applied to aquifer-test results to provide estimates of transmissivity and hydraulic conductivity of the multilayered Floridan aquifer system. Data from a 24-hour aquifer test of the Upper Floridan aquifer were evaluated by using the straight-line Cooper-Jacob analytical method. Data from a 72-hour aquifer test of the Lower Floridan aquifer were simulated by using axisymmetric model simulations. Results of aquifer testing indicated that the Upper Floridan aquifer has a transmissivity of 100,000 feet-squared per day, and the Lower Floridan aquifer has a transmissivity of 7,000 feet-squared per day. A specific storage for the Floridan aquifer system as a result of model calibration was 3E-06 ft–1. Additionally, during a 72-hour aquifer test of the Lower Floridan aquifer, a drawdown response was observed in two Upper Floridan aquifer wells, one of which was more than 1 mile away from the pumped well.

  2. 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

  3. Water-quality characteristics of quaternary unconsolidated-deposit aquifers and lower tertiary aquifers of the Bighorn Basin, Wyoming and Montana, 1999-2001

    Science.gov (United States)

    Bartos, Timothy T.; Eddy-Miller, Cheryl A.; Norris, Jody R.; Gamper, Merry E.; Hallberg, Laura L.

    2004-01-01

    As part of the Yellowstone River Basin National Water Quality Assessment study, ground-water samples were collected from Quaternary unconsolidated-deposit and lower Tertiary aquifers in the Bighorn Basin of Wyoming and Montana from 1999 to 2001. Samples from 54 wells were analyzed for physical characteristics, major ions, trace elements, nutrients, dissolved organic carbon, radionuclides, pesticide compounds, and volatile organic compounds (VOCs) to evaluate current water-quality conditions in both aquifers. Water-quality samples indicated that waters generally were suitable for most uses, and that natural conditions, rather than the effects of human activities, were more likely to limit uses of the waters. Waters in both types of aquifers generally were highly mineralized, and total dissolved-solids concentrations frequently exceeded the U.S. Environmental Protection Agency (USEPA) Secondary Maximum Contaminant Level (SMCL) of 500 milligrams per liter (mg/L). Because of generally high mineralization, waters from nearly one-half of the samples from Quaternary aquifers and more than one-half of the samples from lower Tertiary aquifers were not classified as fresh (dissolved-solids concentration were not less than 1,000 mg/L). The anions sulfate, fluoride, and chloride were measured in some ground-water samples at concentrations greater than SMCLs. Most waters from the Quaternary aquifers were classified as very hard (hardness greater than 180 mg/L), but hardness varied much more in waters from the lower Tertiary aquifers and ranged from soft (less than 60 mg/L) to very hard (greater than 180 mg/L). Major-ion chemistry varied with dissolved-solids concentrations. In both types of aquifers, the predominant anion changes from bicarbonate to sulfate with increasing dissolved-solids concentrations. Samples from Quaternary aquifers with fresh waters generally were calcium-bicarbonate, calcium-sodium-bicarbonate, and calcium-sodium-sulfate-bicarbonate type waters, whereas

  4. Intensively exploited Mediterranean aquifers: resilience and proximity to critical points of seawater intrusion

    Science.gov (United States)

    Mazi, K.; Koussis, A. D.; Destouni, G.

    2013-11-01

    We investigate here seawater intrusion in three prominent Mediterranean aquifers that are subject to intensive exploitation and modified hydrologic regimes by human activities: the Nile Delta Aquifer, the Israel Coastal Aquifer and the Cyprus Akrotiri Aquifer. Using a generalized analytical sharp-interface model, we review the salinization history and current status of these aquifers, and quantify their resilience/vulnerability to current and future sea intrusion forcings. We identify two different critical limits of sea intrusion under groundwater exploitation and/or climatic stress: a limit of well intrusion, at which intruded seawater reaches key locations of groundwater pumping, and a tipping point of complete sea intrusion upto the prevailing groundwater divide of a coastal aquifer. Either limit can be reached, and ultimately crossed, under intensive aquifer exploitation and/or climate-driven change. We show that sea intrusion vulnerability for different aquifer cases can be directly compared in terms of normalized intrusion performance curves. The site-specific assessments show that the advance of seawater currently seriously threatens the Nile Delta Aquifer and the Israel Coastal Aquifer. The Cyprus Akrotiri Aquifer is currently somewhat less threatened by increased seawater intrusion.

  5. Obtaining Samples Representative of Contaminant Distribution in an Aquifer

    International Nuclear Information System (INIS)

    Schalla, Ronald; Spane, Frank A.; Narbutovskih, Susan M.; Conley, Scott F.; Webber, William D.

    2002-01-01

    Historically, groundwater samples collected from monitoring wells have been assumed to provide average indications of contaminant concentrations within the aquifer over the well-screen interval. In-well flow circulation, heterogeneity in the surrounding aquifer, and the sampling method utilized, however, can significantly impact the representativeness of samples as contaminant indicators of actual conditions within the surrounding aquifer. This paper identifies the need and approaches essential for providing cost-effective and technically meaningful groundwater-monitoring results. Proper design of the well screen interval is critical. An accurate understanding of ambient (non-pumping) flow conditions within the monitoring well is essential for determining the contaminant distribution within the aquifer. The ambient in-well flow velocity, flow direction and volumetric flux rate are key to this understanding. Not only do the ambient flow conditions need to be identified for preferential flow zones, but also the probable changes that will be imposed under dynamic conditions that occur during groundwater sampling. Once the in-well flow conditions are understood, effective sampling can be conducted to obtain representative samples for specific depth zones or zones of interest. The question of sample representativeness has become an important issue as waste minimization techniques such as low flow purging and sampling are implemented to combat the increasing cost of well purging and sampling at many hazardous waste sites. Several technical approaches (e.g., well tracer techniques and flowmeter surveys) can be used to determine in-well flow conditions, and these are discussed with respect to both their usefulness and limitations. Proper fluid extraction methods using minimal, (low) volume and no purge sampling methods that are used to obtain representative samples of aquifer conditions are presented

  6. Managed Aquifer Recharge (MAR in Sustainable Urban Water Management

    Directory of Open Access Journals (Sweden)

    Declan Page

    2018-02-01

    Full Text Available To meet increasing urban water requirements in a sustainable way, there is a need to diversify future sources of supply and storage. However, to date, there has been a lag in the uptake of managed aquifer recharge (MAR for diversifying water sources in urban areas. This study draws on examples of the use of MAR as an approach to support sustainable urban water management. Recharged water may be sourced from a variety of sources and in urban centers, MAR provides a means to recycle underutilized urban storm water and treated wastewater to maximize their water resource potential and to minimize any detrimental effects associated with their disposal. The number, diversity and scale of urban MAR projects is growing internationally due to water shortages, fewer available dam sites, high evaporative losses from surface storages, and lower costs compared with alternatives where the conditions are favorable, including water treatment. Water quality improvements during aquifer storage are increasingly being documented at demonstration sites and more recently, full-scale operational urban schemes. This growing body of knowledge allows more confidence in understanding the potential role of aquifers in water treatment for regulators. In urban areas, confined aquifers provide better protection for waters recharged via wells to supplement potable water supplies. However, unconfined aquifers may generally be used for nonpotable purposes to substitute for municipal water supplies and, in some cases, provide adequate protection for recovery as potable water. The barriers to MAR adoption as part of sustainable urban water management include lack of awareness of recent developments and a lack of transparency in costs, but most importantly the often fragmented nature of urban water resources and environmental management.

  7. Residence Times in Central Valley Aquifers Recharged by Dammed Rivers

    Science.gov (United States)

    Loustale, M.; Paukert Vankeuren, A. N.; Visser, A.

    2017-12-01

    Groundwater is a vital resource for California, providing between 30-60% of the state's water supply. Recent emphasis on groundwater sustainability has induced a push to characterize recharge rates and residence times for high priority aquifers, including most aquifers in California's Central Valley. Flows in almost all rivers from the western Sierra to the Central Valley are controlled by dams, altering natural flow patterns and recharge to local aquifers. In eastern Sacramento, unconfined and confined shallow aquifers (depth recharged by a losing reach of the Lower American River, despite the presence of levees with slurry cut-off walls.1 Flow in the Lower American River is controlled through the operation of the Folsom and Nimbus Dams, with a minimum flow of 500 cfs. Water table elevation in wells in close proximity to the river are compared to river stage to determine the effect of river stage on groundwater recharge rates. Additionally, Tritium-3Helium dates and stable isotopes (∂18O and ∂2H) have been measured in monitoring wells 200- 2400 ft lateral distance from the river, and depths of 25 -225 feet BGS. Variation in groundwater age in the vertical and horizontal directions are used to determine groundwater flow path and velocity. These data are then used to calculate residence time of groundwater in the unconfined and confined aquifer systems for the Central Valley in eastern Sacramento. Applying groundwater age tracers can benefit future compliance metrics of the California Sustainable Groundwater Resources Act (SGMA), by quantifying river seepage rates and impacts of groundwater management on surface water resources. 1Moran et al., UCRL-TR-203258, 2004.

  8. Dune management challenges on developed coasts

    Science.gov (United States)

    Elko, Nicole A.; Brodie, Kate; Stockdon, Hilary F.; Nordstrom, Karl F.; Houser, Chris; McKenna, Kim; Moore, Laura; Rosati, Julie D.; Ruggiero, Peter; Thuman, Roberta; Walker, Ian J.

    2015-01-01

    From October 26-28, 2015, nearly 100 members of the coastal management and research communities met in Kitty Hawk, NC, USA to bridge the apparent gap between the coastal dune research of scientists and engineers and the needs of coastal management practitioners. The workshop aimed to identify the challenges involved in building and managing dunes on developed coasts, assess the extent to which scientific knowledge can be applied to the management community, and identify approaches to provide means to bridge the gap between needs and potential solutions.

  9. Estimation of Hydraulic Parameters and Aquifer Properties for a Managed Aquifer Recharge Pilot Study in The Lower Mississippi River Basin

    Science.gov (United States)

    Ozeren, Y.; Rigby, J.; Holt, R. M.

    2017-12-01

    Mississippi River Valley Alluvial Aquifer (MRVAA) is the major irrigation water resource in the in the lower Mississippi River basin. MRVAA has been significantly depleted in the last two decades due to excessive pumping. A wide range of measures to ensure sustainable groundwater supply in the region is currently under investigation. One of the possible solution under consideration is to use Managed Aquifer Recharge (MAR) by artificial recharge. The proposed artificial recharge technique in this study is to collect water through bank filtration, transfer water via pipeline to the critically low groundwater areas by a set of injection wells. A pilot study in the area is underway to investigate the possibility of artificial recharge in the area. As part of this study, a pumping test was carried out on an existing irrigation well along banks of Tallahatchie River near Money, MS. Geophysical surveys were also carried out in the pilot study area. Hydraulic response of the observation wells was used to determine stream bed conductance and aquifer parameters. The collected hydraulic parameters and aquifer properties will provide inputs for small-scale, high-resolution engineering model for abstraction-injection hydraulics along river. Here, preliminary results of the pilot study is presented.

  10. Karst connections between unconfined aquifers and the Upper Floridan aquifer in south Georgia: geophysical evidence and hydrogeological models

    Science.gov (United States)

    Thieme, D. M.; Denizman, C.

    2011-12-01

    Buried karst features in sedimentary rocks of the south Georgia Coastal Plain present a challenge for hydrogeological models of recharge and confined flow within the underlying Upper Floridan aquifer. The Withlacoochee River, the trunk stream for the area, frequently disappears into subsurface caverns as it makes its way south to join the Suwannee River in northern Florida. The Withlacoochee also receives inputs from small ponds and bays which in turn receive spring and seep groundwater inputs. We have mapped karst topography at the "top of rock" using ground-penetrating radar (GPR). Up to seven meters of relief is indicated for the paleotopography on Miocene to Pliocene rocks, contrasting with the more subdued relief of the modern landscape. Current stratigraphic and hydrogeological reconstructions do not incorporate this amount of relief or lateral variation in the confining beds. One "pipe" which is approximately four meters in diameter is being mapped in detail. We have field evidence at this location for rapid movement of surficial pond and river water with a meteoric signature through several separate strata of sedimentary rock into an aquifer in the Hawthorn formation. We use our geophysical and hydrological field evidence to constrain quantitative hydrogeological models for the flow rates into and out of both this upper aquifer and the underlying Upper Floridan aquifer, which is generally considered to be confined by the clays of the Hawthorn.

  11. Impacts of seawater rise on seawater intrusion in the Nile Delta Aquifer, Egypt.

    Science.gov (United States)

    Sefelnasr, Ahmed; Sherif, Mohsen

    2014-01-01

    Several investigations have recently considered the possible impacts of climate change and seawater level rise on seawater intrusion in coastal aquifers. All have revealed the severity of the problem and the significance of the landward movement of the dispersion zone under the condition of seawater level rise. Most of the studies did not consider the possible effects of the seawater rise on the inland movement of the shoreline and the associate changes in the boundary conditions at the seaside and the domain geometry. Such effects become more evident in flat, low land, coastal alluvial plans where large areas might be submerged with seawater under a relatively small increase in the seawater level. None of the studies combined the effect of increased groundwater pumping, due to the possible decline in precipitation and shortage in surface water resources, with the expected landward shift of the shore line. In this article, the possible effects of seawater level rise in the Mediterranean Sea on the seawater intrusion problem in the Nile Delta Aquifer are investigated using FEFLOW. The simulations are conducted in horizontal view while considering the effect of the shoreline landward shift using digital elevation models. In addition to the basic run (current conditions), six different scenarios are considered. Scenarios one, two, and three assume a 0.5 m seawater rise while the total pumping is reduced by 50%, maintained as per the current conditions and doubled, respectively. Scenarios four, five, and six assume a 1.0 m seawater rise and the total pumping is changed as in the first three scenarios. The shoreline is moved to account for the seawater rise and hence the study domain and the seaside boundary are modified accordingly. It is concluded that, large areas in the coastal zone of the Nile Delta will be submerged by seawater and the coast line will shift landward by several kilometers in the eastern and western sides of the Delta. Scenario six represents

  12. 76 FR 38313 - Magnuson-Stevens Act Provisions; Fisheries Off West Coast States; Pacific Coast Groundfish...

    Science.gov (United States)

    2011-06-30

    ... are available, preventing additional harvest in fisheries that are important to coastal communities... document and undergo proposed and final rulemaking before these actions need to be in effect. For the... delay could impair achievement of one of the Pacific Coast Groundfish FMP goals to prevent overfishing...

  13. 78 FR 75268 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

    Science.gov (United States)

    2013-12-11

    ... Rationalization Program; Cost Recovery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... recovery program for the Pacific coast groundfish trawl rationalization program, as required by the...). Allocations to the limited entry trawl fleet for certain species were developed through a parallel process...

  14. 78 FR 7371 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

    Science.gov (United States)

    2013-02-01

    ... Rationalization Program; Cost Recovery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... Office rule goes final before the cost recovery program rule and if it would affect the appeals process... would implement a cost recovery program for the Pacific coast groundfish trawl rationalization program...

  15. Meteorologically induced modulation in sea level off Tikkavanipalem Coast - Central east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desai, R.G.P.; VijayKumar, K.; Mehra, P.; Nagvekar, S.

    on simultaneous observations of tidal and surface meteorological parameters in four temporal segments of 1-month duration each during a 1-year period in 1997-98. Sea level oscillations along the Tikkavanipalem segment of the central east coast of India contain...

  16. A Holistic Evaluation of a Typical Coast Nourishment on the Danish West Coast

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Frigaard, Peter; Wahl, Niels Arne

    2008-01-01

    The case described in this article regards 4.7 km of beach in Ferring, situated approx. 5 km south to the mouth of the Limfjord strait on the west coast of Denmark. In 2005, this section of the beach was nourished with 721,000 m3 of material in order to protect backshore properties, natural...

  17. A Holistic Evaluation of a Typical Coast Nourishment on the Danish West Coast

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Frigaard, Peter; Wahl, Niels Arne

    2007-01-01

    The case described in this article regards 4.7 km of beach in Ferring, situated approx. 5 km south to the mouth of the Limfjord strait on the west coast of Denmark. In 2005, this section of the beach was nourished with 721,000 m3 of material in order to protect backshore properties, natural herit...

  18. 75 FR 67809 - Magnuson-Stevens Act Provisions; Fisheries Off West Coast States; Pacific Coast Groundfish...

    Science.gov (United States)

    2010-11-03

    ... economic benefits, create individual economic stability, provide full utilization of the trawl sector... taken in the U.S. exclusive economic zone (EEZ) off the coasts of Washington, Oregon, and California... holistic alternatives relative to the biological and socio-economic environment and consistent with the...

  19. Site characterization plan: Gulf Coast salt domes

    International Nuclear Information System (INIS)

    1983-12-01

    The National Waste Terminal Storage (NWTS) program of the US Department of Energy (DOE) is responsible for developing technology and providing facilities for safe, environmentally acceptable, permanent disposal of high-level nuclear waste. The Office of Nuclear Waste Isolation has been intensively investigating Gulf Coast Salt Dome Basin salt domes and bedded salt in Texas and Utah since 1978. In the Gulf Coast, the application of screening criteria in the region phase led to selection of eight domes for further study in the location phase. Further screening in the area phase identified four domes for more intensive study in the location phase: Oakwood Dome, Texas; Vacherie Dome, Louisiana; and Richton Dome and Cypress Creek Dome, Mississippi. For each dome, this Site Characterization Plan identifies specific hydrologic, geologic, tectonic, geochemical, and environmental key issues that are related to the DOE/NWTS screening criteria or affect the feasibility of constructing an exploratory shaft. The Site Characterization Plan outlines studies need to: (1) resolve issues sufficiently to allow one or more salt domes to be selected and compared to bedded salt sites in order to determine a prime salt site for an exploratory shaft; (2) conduct issue-related studies to provide a higher level of confidence that the preferred salt dome site is viable for construction of an exploratory shaft; and (3) provide a vehicle for state input to issues. Extensive references, 7 figures, 20 tables

  20. East coast gas - the big picture

    International Nuclear Information System (INIS)

    Drummond, K.J.

    1998-01-01

    The North American conventional gas resource base was reviewed and an explanation of how Canada's East coast fits into the overall picture was given. At 1996 year end, the total conventional ultimate natural gas resource base for North America was estimated to be 2,695 trillion cubic feet. The most important supply areas are Canada and the United States. Mexico and Alaska are expected to play only a minor role in the overall North American supply. Approximately half of the conventional gas estimated to exist in North America remains to be discovered. Only 78 per cent from the half that has been discovered has been produced, and only 22 per cent of it is remaining as reserves. Of the undiscovered natural gas resource, 38 per cent is in the frontier regions of Alaska and Canada. The growing importance of the East coast of North America as markets for natural gas was reviewed. The distribution of ultimate conventional marketable gas resources for Canada was described. The potential of the Western Canadian Sedimentary Basin (WCSB) and selected frontier areas were assessed. The report showed an undiscovered conventional marketable gas estimate of 122 trillion cubic feet for the WCSB and 107 trillion cubic feet for the Frontier areas. The two most significant areas of discovery in eastern Canada were considered to be the Hibernia oil field on the Grand Banks and the Venture gas field of the Scotian Shelf. 2 tabs., 7 figs