WorldWideScience

Sample records for sandy aquifer system

  1. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

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

    1991-01-01

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

  2. Copper and zinc distribution coefficients for sandy aquifer materials

    DEFF Research Database (Denmark)

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

    2000-01-01

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

  3. Model Simulations of a Field Experiment on Cation Exchange-affected Multicomponent Solute Transport in a Sandy Aquifer

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Ammentorp, Hans Christian; Christensen, Thomas Højlund

    1993-01-01

    A large-scale and long-term field experiment on cation exchange in a sandy aquifer has been modelled by a three-dimensional geochemical transport model. The geochemical model includes cation-exchange processes using a Gaines-Thomas expression, the closed carbonate system and the effects of ionic...... of 800 days due to a substantially attenuation in the aquifer. The observed and the predicted breakthrough curves showed a reasonable accordance taking the duration of the experiment into account. However, some discrepancies were observed probably caused by the revealed non-ideal exchange behaviour of K+....

  4. Spatial variability of hydraulic conductivity of an unconfined sandy aquifer determined by a mini slug test

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Hinsby, Klaus; Christensen, Thomas Højlund;

    1992-01-01

    The spatial variability of the hydraulic conductivity in a sandy aquifer has been determined by a mini slug test method. The hydraulic conductivity (K) of the aquifer has a geometric mean of 5.05 × 10−4 m s−1, and an overall variance of 1n K equal to 0.37 which corresponds quite well to the results...... obtained by two large scale tracer experiments performed in the aquifer. A geological model of the aquifer based on 31 sediment cores, proposed three hydrogeological layers in the aquifer concurrent with the vertical variations observed with respect to hydraulic conductivity. The horizontal correlation...... length of the hydraulic conductivity has been determined for each of the three hydrogeological layers and is found to be small (1–2.5 m). The asymptotic longitudinal dispersivity of the aquifer has been estimated from the variance in hydraulic conductivity and the horizontal correlation length...

  5. Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan

    2001-01-01

    Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...

  6. Denitrification coupled to pyrite oxidation and changes in groundwater quality in a shallow sandy aquifer

    NARCIS (Netherlands)

    Zhang, Y.-C.; Slomp, C.P.; Broers, H.P.; Passier, H.F.; Cappellen, P. van

    2009-01-01

    This study focuses on denitrification in a sandy aquifer using geochemical analyses of both sediment and groundwater, combined with groundwater age dating (3H/3He). The study sites are located underneath cultivated fields and an adjacent forested area at Oostrum, The Netherland

  7. Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan

    2001-01-01

    Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...... result of these interactions between different types of geochemical processes is an anoxic groundwater enriched in bicarbonate and sodium....

  8. Degradation of the Pesticides Mecoprop and Atrazine in Unpolluted Sandy Aquifers

    DEFF Research Database (Denmark)

    Klint, Mikala; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    The potential for biodegradation of the pesticides mecoprop ((+/-)-2-(4-chloro-2-methyl-phenoxy)propionic acid) and atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in an aerobic aquifer was investigated in laboratory batch experiments. The experiments were performed with groundwater...... and suspensions of groundwater and aquifer sediment collected from a pristine sandy aquifer. Following a lag period of 35 to 40 d, mecoprop in a concentration of 100 mu-g/L was degraded in 30 d in groundwater at 10 degree C. New additions of 100 to 140 mu-g mecoprop/L were degraded within a week. In suspensions...... of groundwater and aquifer sediment, mecoprop in the concentration range 75 to 300 mu-g/L was degraded in 15 d, following a lag period of less than 7 d. Experiments performed with sediments taken from different depths indicate that there was a considerable variation in the degradation potential within...

  9. Large-Scale Experiments in a Sandy Aquifer in Denmark

    DEFF Research Database (Denmark)

    Jensen, Karsten Høgh; Bitsch, Karen Bue; Bjerg, Poul Løgstrup

    1993-01-01

    vertical directions was very small. The horizontal transport parameters of the advection-dispersion equation were investigated by applying an optimization model to observed breakthrough curves of tritium representing depth averaged concentrations. No clear trend in dispersion parameters with travel...... distance for distances between 50 and 200 m could be found, suggesting that the asymptotic stage was reached within a short distance from the point of injection. A three-dimensional numerical model for flow and transport was applied to the aquifer in order to quantify the dispersivity parameters more...

  10. Transport behavior of groundwater protozoa and protozoan-sized microspheres in sandy aquifer sediments

    Science.gov (United States)

    Harvey, R.W.; Kinner, N.E.; Bunn, A.; MacDonald, D.; Metge, D.

    1995-01-01

    Transport behaviors of unidentified flagellated protozoa (flagellates) and flagellate-sized carboxylated microspheres in sandy, organically contaminated aquifer sediments were investigated in a small-scale (1 to 4-m travel distance) natural-gradient tracer test on Cape Cod and in flow-through columns packed with sieved (0.5-to 1.0-mm grain size) aquifer sediments. The minute (average in situ cell size, 2 to 3 ??m) flagellates, which are relatively abundant in the Cape Cod aquifer, were isolated from core samples, grown in a grass extract medium, labeled with hydroethidine (a vital eukaryotic stain), and coinjected into aquifer sediments along with bromide, a conservative tracer. The 2-??m flagellates appeared to be near the optimal size for transport, judging from flowthrough column experiments involving a polydispersed (0.7 to 6.2 ??m in diameter) suspension of carboxylated microspheres. However, immobilization within the aquifer sediments accounted for a log unit reduction over the first meter of travel compared with a log unit reduction over the first 10 m of travel for indigenous, free-living groundwater bacteria in earlier tests. High rates of flagellate immobilization in the presence of aquifer sediments also was observed in the laboratory. However, immobilization rates for the laboratory-grown flagellates (initially 4 to 5 ??m) injected into the aquifer were not constant and decreased noticeably with increasing time and distance of travel. The decrease in propensity for grain surfaces was accompanied by a decrease in cell size, as the flagellates presumably readapted to aquifer conditions. Retardation and apparent dispersion were generally at least twofold greater than those observed earlier for indigenous groundwater bacteria but were much closer to those observed for highly surface active carboxylated latex microspheres. Field and laboratory results suggest that 2- ??m carboxylated microspheres may be useful as analogs in investigating several abiotic

  11. Enhanced degradation of mono aromatic hydrocarbons in sandy aquifer materials

    Energy Technology Data Exchange (ETDEWEB)

    Corseuil, Henry X. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Sanitaria; Weber Junior, W.J. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Civil and Environmental Engineering

    1993-12-31

    The use of an inoculation technique to enhance rates of in-situ biodegradation of toxic organic contaminants by increasing subsurface populations of specific microorganisms is described. An external biologically active carbon (BAC) adsorber is demonstrated to be an efficient reactor system for collection, acclimation and enrichment of microorganisms for the inoculation process (author). 15 refs., 3 figs.

  12. Simulation of atrazine and metabolite transport and fate in a sandy-till aquifer

    Science.gov (United States)

    Levy, Jonathan; Chesters, Gordon

    1995-11-01

    In a 2.5-yr field study we determined the distribution of atrazine and its metabolites in a sandy-till aquifer overlying Cambrian sandstone in a dairy farming area. Flow paths are predominantly downward at piezometer nests where vertical hydraulic gradients dominate. Atrazine and desethylated atrazine concentrations along those flow paths generally decrease with increasing estimated groundwater travel time to the monitoring points. A one-dimensional contaminant transport model is developed in FORTRAN incorporating major chemical processes and dispersion along simulated flow paths. Separate simulations of atrazine and desethylated atrazine transport to individual piezometers are made, each with an appropriate average groundwater velocity. Regression equations are developed, based on an extensive literature review, to estimate acceptable sorption and dispersivity coefficients for the transport model. The one-dimensional simulations are calibrated using the field concentration-travel time relationships for atrazine and desethylated atrazine. The calibration procedure provides estimates of atrazine and desethylated atrazine degradation rates in groundwater corresponding to half-lives of 3470 and 2770 days, respectively. Although uncertain, the estimates provide evidence of much slower degradation in the aquifer than indicated by laboratory experiments. Using the calibrated transport parameter values, simulations of long-term steady-state leaching to the water table demonstrate that even with such slow degradation rates, steady-state concentrations at most piezometers are reached within ˜ 20 yr. Concentrations in the underlying sandstone aquifer are therefore not expected to increase substantially over time due to continued atrazine use. However, the slow degradation rates mean that even with the most optimistic condition, i.e. all input to the aquifer ceases in response to a cessation of atrazine application, it may take more than a decade for concentrations deeper in

  13. Spectral induced polarization measurements for predicting the hydraulic conductivity in sandy aquifers

    Directory of Open Access Journals (Sweden)

    M. Attwa

    2013-10-01

    Full Text Available Field and laboratory spectral induced polarization (SIP measurements are integrated to characterize the hydrogeological conditions at the Schillerslage test site in Germany. The phase images are capable of monitoring thin peat layers within the sandy aquifers. However, the field results show limitations of decreasing resolution with depth. In comparison with the field inversion results, the SIP laboratory measurements show a certain shift in SIP response due to different compaction and sorting of the samples. The SIP data are analyzed to derive an empirical relationship for predicting the hydraulic conductivity (K. In particular, two significant but weak correlations between individual real resistivities (ρ' and relaxation times (τ, based on a Debye decomposition (DD model, with measured K are found for the upper groundwater aquifer. The maximum relaxation time (τmax and logarithmically weighted average relaxation time (τlw show a better relation with K values than the median value τ50. A combined power law relation between individual ρ' and τ with K is developed with an expression of A · (ρ'B · (τlwC, where A, B and C are determined using a least-squares fit between the measured and predicted K. The suggested approach with the calculated coefficients of the first aquifer is applied for the second. Results show good correlation with the measured K indicating that the derived relationship is superior to single phase angle models as Börner or Slater models.

  14. Simulating transport and removal of xylene during remediation of a sandy aquifer

    Science.gov (United States)

    Schäfer, Wolfgang; Therrien, René

    1995-09-01

    Xylene, originating from a spill, is present both as a nonaqueous-phase liquid (NAPL) at residual saturation near the water table, and as a dissolved groundwater component contaminating a sandy aquifer beneath an abandoned refinery. Three remediation wells are in operation on the site to prevent further xylene migration in the groundwater. Field observations indicate that microbially-mediated xylene degradation and oxygen and nitrate reduction occur in the aquifer. To realistically simulate dissolved xylene migration at this site, a three-dimensional numerical flow and transport model incorporating biochemical multispecies interactions and xylene dissolution from the NAPL has been developed. In the calibration process the variable contact area between the NAPL and groundwater and the vertical transverse dispersivity were identified as crucial parameters controlling the fate of xylene. The simultaneous modeling of a whole set of related reactive species made it also possible to quantify the observed biodegradation. Results indicate that it contributes in the same order of magnitude to total xylene removal than does extraction by the wells. The calibrated model will be used to assist in the design of an in situ bioremediation scheme, where biodegradation in the aquifer is enhanced by injection of an electron acceptor.

  15. Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: An experimental and mechanistic modeling study

    NARCIS (Netherlands)

    Regelink, I.C.; Temminghoff, E.J.M.

    2011-01-01

    Mining activities and industries have created nickel (Ni) contaminations in many parts of the world. The objective of this study is to increase our understanding of Ni adsorption and Nickel-Aluminium Layered Double Hydroxide (Ni-Al LDH) precipitation to reduce Ni mobility in a sandy soil aquifer. At

  16. Spectral induced polarization measurements for environmental purposes and predicting the hydraulic conductivity in sandy aquifers

    Directory of Open Access Journals (Sweden)

    M. Attwa

    2013-04-01

    Full Text Available Low-frequency field and laboratory induced polarization measurements are carried out to characterize the hydrogeological conditions at Schillerslage test site in Germany. The laboratory spectral induced polarization (SIP data are analyzed to derive an empirical relationship for predicting the hydraulic conductivity (K in the field scale. On the other hand, the results from SIP sounding and profiling field data indicate that the method identifies the lithological layers with sufficient resolution to achieve our objectives. Two main Quaternary groundwater aquifers separated by a till layer can be well differentiated. Furthermore, the phase images are also capable of monitoring thin peat layers within the sandy groundwater aquifer. However, the field results show limitations of decreasing resolution with depth and/or low data coverage. Similarly, the SIP laboratory results show a certain shift in SIP response due to different compaction and sorting of the samples. The overall results obtained show that the integration of field and laboratory SIP measurements is an efficient tool to avoid a hydrogeological misinterpretation. In particular, two significant but weak correlations between individual real resistivities (ρ' and relaxation times (τ, based on a Debye decomposition (DD model, with measured K are found for the upper groundwater aquifer. While the maximum relaxation time (τmax and logarithmically weighted average relaxation time (τlw show a better relation with K values than the median value τ50, however, the single relationships are weak. A combined power law relation between individual ρ' and/or τ with K is developed with an expression of A · (ρ'B · (τlwC, where A, B and C are determined using a least-squares fit between the measured and predicted K. The suggested approach with the calculated coefficients of the first aquifer is applied for the second one. The results indicate a good correlation with the measured K and prove to be

  17. Transport of bisphenol-A in sandy aquifer sediment: Column experiment.

    Science.gov (United States)

    Zakari, Sissou; Liu, Hui; Tong, Lei; Wang, Yan; Liu, Jianfeng

    2016-02-01

    The present paper aims to study the transport behavior of bisphenol-A (BPA) in sandy aquifer so as to provide important parameters for the prediction and control of contaminant plume in aquifer. Miscible displacement experiments were conducted and the breakthrough curves (BTCs) were simulated using HYDRUS-1D software. The effects of pore-water velocity (10-52 cm h(-1)) and initial concentration (2.5-40 mg L(-1)) on the sorption were also investigated. The BTCs of BPA fit the linear first-order non-equilibrium two-site model. The parameters such as partition coefficient (K(d)), the fraction of instantaneous adsorption on "Type-1" sites (F), the first order sorption rate coefficient for the kinetic non-equilibrium (type-2) sites (α), the retardation coefficient (R), and sorption capacity (q(column)) were computed. Results showed that BPA transported 0.11-0.83 m with various pore water velocity in sandy sediment column when water flowed 1 m. The sorption of BPA was mainly caused by the instantaneous surface adsorption as F varied from 0.596 to 0.908. The transport velocity of BPA was affected by pore water velocity (v) and followed the linear equation 1/R = 0.0600 + 0.0110v (r(2) = 0.9724). The parameter K(d) were also closely related to v and followed the equation LnK(d) = 1.0023-0.0482v (r(2) = 0.9690). The sorption capacity was more related to the initial BPA concentration (C0) and followed the linear equation q(column) = 0.265 + 0.253C0 (r(2) = 0.9727). The parameter α was affected by both v and C0 whereas F was not dramatically affected by both.

  18. Virus and bacteria transport in a sandy aquifer, Cape Cod, MA

    Science.gov (United States)

    Bales, Roger C.; Li, Shimin; Maguire, Kimberly M.; Yahya, Moyasar T.; Gerba, Charles P.; Harvey, Ronald W.

    1995-01-01

    Transport of the bacteriophage PRD-1, bacteria, and latex microspheres was studied in a sandy aquifer under natural-gradient conditions. The field injection was carried out at the U.S. Geological Survey's Toxic Substances Hydrology research site on Cape Cod. The three colloids and a salt tracer (Br−) moved along the same path. There was significant attenuation of the phage, with PRD-1 peak concentrations less than 0.001 percent of Br− peaks 6 m from the source; but the low detection limit (one per ml) enabled tracking movement of the PRD-1 plume for 12 m downgradient over the 25-day experiment. Attenuation of phage was apparently due to retention on soil particles (adsorption). Attenuation of bacteria and microspheres was less, with peak concentrations 6 m from the source on the order of 10 and 0.4 percent of Br−, respectively. Injection of a high-pH pulse of water 20 days into the experiment resulted in significant remobilization of retained phage, demonstrating that attached phage remained viable, and that PRD-1 attachment to and detachment from the sandy soil particles was highly pH dependent. Phage behavior in this experiment, i.e. attenuation at pH 5.7 and rapid resuspension at pH 6–8, was consistent with that observed previously in laboratory column studies. Results illustrate that biocolloids travel in a fairly narrow plume in sandy (relatively homogeneous) media, with virus concentrations dropping below detection limit several meters away from the source; bacteria concentrations above detection limits can persist over longer distances.

  19. Implications of Fecal Bacteria Input from Latrine-Polluted Ponds for Wells in Sandy Aquifers

    Science.gov (United States)

    Knappett, Peter S. K.; McKay, Larry D.; Layton, Alice; Williams, Daniel E.; Alam, Md. J.; Huq, Md. R.; Mey, Jacob; Feighery, John E.; Culligan, Patricia J.; Mailloux, Brian J.; Zhuang, Jie; Escamilla, Veronica; Emch, Michael; Perfect, Edmund; Sayler, Gary S.; Ahmed, Kazi M.; van Geen, Alexander

    2012-01-01

    Ponds receiving latrine effluents may serve as sources of fecal contamination to shallow aquifers tapped by millions of tube-wells in Bangladesh. To test this hypothesis, transects of monitoring wells radiating away from four ponds were installed in a shallow sandy aquifer underlying a densely populated village and monitored for 14 months. Two of the ponds extended to medium sand. Another pond was sited within silty sand and the last in silt. The fecal indicator bacterium E. coli was rarely detected along the transects during the dry season and was only detected near the ponds extending to medium sand up to 7 m away during the monsoon. A log-linear decline in E. coli and Bacteroidales concentrations with distance along the transects in the early monsoon indicates that ponds excavated in medium sand were the likely source of contamination. Spatial removal rates ranged from 0.5-1.3 log10/m. After the ponds were artificially filled with groundwater to simulate the impact of a rain storm, E. coli levels increased near a pond recently excavated in medium sand, but no others. These observations show that adjacent sediment grain-size and how recently a pond was excavated influence how much fecal contamination ponds receiving latrine effluents contribute to neighboring groundwater. PMID:22191430

  20. Implications of fecal bacteria input from latrine-polluted ponds for wells in sandy aquifers.

    Science.gov (United States)

    Knappett, Peter S K; McKay, Larry D; Layton, Alice; Williams, Daniel E; Alam, Md J; Huq, Md R; Mey, Jacob; Feighery, John E; Culligan, Patricia J; Mailloux, Brian J; Zhuang, Jie; Escamilla, Veronica; Emch, Michael; Perfect, Edmund; Sayler, Gary S; Ahmed, Kazi M; van Geen, Alexander

    2012-02-07

    Ponds receiving latrine effluents may serve as sources of fecal contamination to shallow aquifers tapped by millions of tube-wells in Bangladesh. To test this hypothesis, transects of monitoring wells radiating away from four ponds were installed in a shallow sandy aquifer underlying a densely populated village and monitored for 14 months. Two of the ponds extended to medium sand. Another pond was sited within silty sand and the last in silt. The fecal indicator bacterium E. coli was rarely detected along the transects during the dry season and was only detected near the ponds extending to medium sand up to 7 m away during the monsoon. A log-linear decline in E. coli and Bacteroidales concentrations with distance along the transects in the early monsoon indicates that ponds excavated in medium sand were the likely source of contamination. Spatial removal rates ranged from 0.5 to 1.3 log(10)/m. After the ponds were artificially filled with groundwater to simulate the impact of a rain storm, E. coli levels increased near a pond recently excavated in medium sand, but no others. These observations show that adjacent sediment grain-size and how recently a pond was excavated influence the how much fecal contamination ponds receiving latrine effluents contribute to neighboring groundwater.

  1. Understanding the fate of sanitation-related nutrients in a shallow sandy aquifer below an urban slum area

    Science.gov (United States)

    Nyenje, P. M.; Havik, J. C. N.; Foppen, J. W.; Muwanga, A.; Kulabako, R.

    2014-08-01

    We hypothesized that wastewater leaching from on-site sanitation systems to alluvial aquifers underlying informal settlements (or slums) may end up contributing to high nutrient loads to surface water upon groundwater exfiltration. Hence, we conducted a hydro-geochemical study in a shallow sandy aquifer in Bwaise III parish, an urban slum area in Kampala, Uganda, to assess the geochemical processes controlling the transport and fate of dissolved nutrients (NO3, NH4 and PO4) released from on-site sanitation systems to groundwater. Groundwater was collected from 26 observation wells. The samples were analyzed for major ions (Ca, Mg, Na, Mg, Fe, Mn, Cl and SO4) and nutrients (o-PO4, NO3 and NH4). Data was also collected on soil characteristics, aquifer conductivity and hydraulic heads. Geochemical modeling using PHREEQC was used to determine the level of o-PO4 control by mineral solubility and sorption. Groundwater below the slum area was anoxic and had near neutral pH values, high values of EC (average of 1619 μS/cm) and high concentrations of Cl (3.2 mmol/L), HCO3 (11 mmol/L) and nutrients indicating the influence from wastewater leachates especially from pit latrines. Nutrients were predominantly present as NH4 (1-3 mmol/L; average of 2.23 mmol/L). The concentrations of NO3 and o-PO4 were, however, low: average of 0.2 mmol/L and 6 μmol/L respectively. We observed a contaminant plume along the direction of groundwater flow (NE-SW) characterized by decreasing values of EC and Cl, and distinct redox zones. The redox zones transited from NO3-reducing in upper flow areas to Fe-reducing in the lower flow areas. Consequently, the concentrations of NO3 decreased downgradient of the flow path due to denitrification. Ammonium leached directly into the alluvial aquifer was also partially removed because the measured concentrations were less than the potential input from pit latrines (3.2 mmol/L). We attributed this removal (about 30%) to anaerobic ammonium oxidation

  2. GC estimation of organic hydrocarbons that threaten shallow Quaternary sandy aquifer Northwestern Gulf of Suez, Egypt.

    Science.gov (United States)

    Zawrah, M F; Ebiad, M A; Rashad, A M; El-Sayed, E; Snousy, Moustafa Gamal; Tantawy, M A

    2014-11-01

    Soil and groundwater contamination is one of the important environmental problems at petroleum-related sites, which causes critical environmental and health defects. Severe petroleum hydrocarbon contamination from coastal refinery plant was detected in a shallow Quaternary sandy aquifer is bordered by Gulf in the Northwestern Gulf of Suez, Egypt. The overall objective of this investigation is to estimate the organic hydrocarbons in shallow sandy aquifers, released from continuous major point-source of pollution over a long period of time (91 years ago). This oil refinery contamination resulted mainly in the improper disposal of hydrocarbons and produced water releases caused by equipment failures, vandalism, and accidents that caused direct groundwater pollution or discharge into the gulf. In order to determine the fate of hydrocarbons, detailed field investigations were made to provide intensive deep profile information. Eight composite randomly sediment samples from a test plot were selected for demonstration. The tested plot was 50 m long × 50 m wide × 70 cm deep. Sediment samples were collected using an American auger around the point 29° 57' 33″ N and 32° 30' 40″ E in 2012 and covered an area of 2,500 m(2) which represents nearly 1/15 of total plant area (the total area of the plant is approximately 3.250 km(2)). The detected total petroleum hydrocarbons (TPHs) were 2.44, 2.62, 4.54, 4.78, 2.83, 3.22, 2.56, and 3.13 wt%, respectively. TPH was calculated by differences in weight and subjected to gas chromatography (GC). Hydrocarbons were analyzed on Hewlett-Packard (HP-7890 plus) gas chromatograph equipped with a flame ionization detector (FID). The percentage of paraffine of the investigated TPH samples was 7.33, 7.24, 7.58, 8.25, 10.25, 9.89, 14.77, and 17.53 wt%, respectively.

  3. Isotopic and microbiological signatures of pyrite-driven denitrification in a sandy aquifer

    NARCIS (Netherlands)

    Zhang, Y.-C.; Slomp, C.P.; Broers, H.P.; Bostick, B.; Passier, H.F.; Böttcher, M.E.; Omoregie, E.O.; Lloyd, J.R.; Polya, D.A.; Van Cappellen, P.

    2012-01-01

    Denitrificationdriven by pyrite oxidation can play a major role in the removal of nitrate from groundwater systems. As yet, limited information is available on the interactions between the micro-organisms and aqueous and mineral phases in aquifers where pyrite oxidation is occurring. In this study,

  4. The addition of organic carbon and nitrate affects reactive transport of heavy metals in sandy aquifers

    KAUST Repository

    Satyawali, Yamini

    2011-04-01

    Organic carbon introduction in the soil to initiate remedial measures, nitrate infiltration due to agricultural practices or sulphate intrusion owing to industrial usage can influence the redox conditions and pH, thus affecting the mobility of heavy metals in soil and groundwater. This study reports the fate of Zn and Cd in sandy aquifers under a variety of plausible in-situ redox conditions that were induced by introduction of carbon and various electron acceptors in column experiments. Up to 100% Zn and Cd removal (from the liquid phase) was observed in all the four columns, however the mechanisms were different. Metal removal in column K1 (containing sulphate), was attributed to biological sulphate reduction and subsequent metal precipitation (as sulphides). In the presence of both nitrate and sulphate (K2), the former dominated the process, precipitating the heavy metals as hydroxides and/or carbonates. In the presence of sulphate, nitrate and supplemental iron (Fe(OH)3) (K3), metal removal was also due to precipitation as hydroxides and/or carbonates. In abiotic column, K4, (with supplemental iron (Fe(OH)3), but no nitrate), cation exchange with soil led to metal removal. The results obtained were modeled using the reactive transport model PHREEQC-2 to elucidate governing processes and to evaluate scenarios of organic carbon, sulphate and nitrate inputs. © 2010 Elsevier B.V.

  5. Southeastern Coastal Plain aquifer system

    Data.gov (United States)

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

  6. Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: an experimental and mechanistic modeling study.

    Science.gov (United States)

    Regelink, Inge C; Temminghoff, Erwin J M

    2011-03-01

    Mining activities and industries have created nickel (Ni) contaminations in many parts of the world. The objective of this study is to increase our understanding of Ni adsorption and Nickel-Aluminium Layered Double Hydroxide (Ni-Al LDH) precipitation to reduce Ni mobility in a sandy soil aquifer. At pH ≥ 7.2 both adsorption and Ni-Al LDH precipitation occurred. In batch experiments with the sandy soil up to 70% of oxalate-extractable Al was taken up in LDH formation during 56 days. In a long term column experiment 99% of influent Ni was retained at pH 7.5 due to Ni adsorption (≈ 34%) and Ni-Al LDH precipitation (≈ 66%) based on mechanistic reactive transport modeling. The subsequent leaching at pH 6.5 could be largely attributed to desorption. Our results show that even in sandy aquifers with relatively low Al content, Ni-Al LDH precipitation is a promising mechanism to immobilize Ni.

  7. Identification of TCE and PCE sorption and biodegradation parameters in a sandy aquifer for fate and transport modelling: batch and column studies

    OpenAIRE

    Kret, E.; Kiecak, A.; Malina, G.; Nijenhuis, I.; Postawa, A.

    2015-01-01

    The main aim of this study was to determine the sorption and biodegradation parameters of trichloroethene (TCE) and tetrachloroethene (PCE) as input data required for their fate and transport modelling in a Quaternary sandy aquifer. Sorption was determined based on batch and column experiments, while biodegradation was investigated using the compound-specific isotope analysis (CSIA). The aquifer materials medium (soil 1) to fine (soil 2) sands and groundwater samples came from the representat...

  8. Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

    Science.gov (United States)

    Bohlke, Johnkarl F.; Hatzinger, P.B.; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

    2009-01-01

    An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br– as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (e18O/e37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ~0.8 (e18O/e15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (e18O/e37Cl, e18O/e15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent e values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.

  9. Degradation of the Pesticides Mecoprop and Atrazine in Unpolluted Sandy Aquifers

    DEFF Research Database (Denmark)

    Klint, Mikala; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    The potential for biodegradation of the pesticides mecoprop ((+/-)-2-(4-chloro-2-methyl-phenoxy)propionic acid) and atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in an aerobic aquifer was investigated in laboratory batch experiments. The experiments were performed with groundwater...... the aquifer. Atrazine was not degraded during an incubation period of 539 d in groundwater and 174 d in suspensions of groundwater and aquifer sediment. The addition of nutrients, primary substrates (acetate and naphthalene), and a pH or temperature increase had not effect on the recalcitrance of atrazine....

  10. A mini slug test method for determination of a local hydraulic conductivity of an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Hinsby, Klaus; Bjerg, Poul Løgstrup; Andersen, Lars J.;

    1992-01-01

    from level to level and thereby establish vertical profiles of the hydraulic conductivity. The head data from the test well are recorded with a 10 mm pressure transducer, and the initial head difference required is established by a small vacuum pump. The method described has provided 274 spatially......A new and efficient mini slug test method for the determination of local hydraulic conductivities in unconfined sandy aquifers is developed. The slug test is performed in a small-diameter (1 inch) driven well with a 0.25 m screen just above the drive point. The screened drive point can be driven...... distributed measurements of a local hydraulic conductivity at a tracer test site at Vejen, Denmark. The mini slug test results calculated by a modified Dax slug test analysing method, applying the elastic storativity in the Dax equations instead of the specific yield, are in good accordance with the results...

  11. Monitoring a shallow geothermal experiment in a sandy aquifer using electrical resistivity tomography: a feasibility study

    Science.gov (United States)

    Hermans, Thomas; Vandenbohede, Alexander; Nguyen, Frederic; Lebbe, Luc

    2010-05-01

    The use of low-enthalpy geothermal ressources is increasingly growing in Europe and around the world. This domain constitutes an essential field of research and development in the diversification of energy ressources to hinder global warming. The advantages of very low temperature systems are, first, that they are much more available than the geothermal high temperature, since the underground often contains important shallow aquifers (e.g. alluvial plains), and second, that their exploitation involve relatively low costs of implementation. Very low energy systems exhibit underground fluid with a temperature ranging from 5 to 30 ° C, which may be used for cooling or heating. The two main modes of exploitation of geothermal energy rely on the extraction of the hydrothermal fluid in the aquifer from wells and on the circulation of a heat transfer fluid in a closed and buried geothermal circuit. Underground heat exchange and overall exploitation system design may be undertaken in an optimized and sustainable fashion if the parameters governing the coupled heat transport and flow equations are know to a certain degree. As for many underground reservoir problems, sufficient knowledge on the distribution of the parameters of interests (e.g. thermal conductivity, thermal diffusivity, thermomechanic dispersitivity, effective porosity) must be obtained to perform reliable predictions. Designing novel experiments to estimate those parameters in-situ is therefore essential. In this framework, we examine the feasibility of a thermal tracer experiment similar to the ones performed in hydrogeology or hydrogeophysics. The test consists in following the evolution of a heat plume through the underground as it is injected in one well and pumped to another one. The thermal tracer evolution is followed by gathering electrical resistivity (ERT) images in a time-lapse framework over 10 days. In this contribution, we examine the potential of ERT to image such thermal plume and its

  12. Methanogenesis in a shallow sandy aquifer, Rømø, Denmark

    DEFF Research Database (Denmark)

    Hansen, L.K.; Jakobsen, Rasmus; Postma, Diederik Jan

    2001-01-01

    part of the aquifer, rates of acetate oxidation of up to 4 mM/yr were measured in the same zone where sulfate reduction and the reduction of iron oxides takes place. Total methane formation rates range from 0.1 to 4 mM/yr and proceeds through both the pathway of CO2 reduction and acetate fermentation....... CO2 reduction was found to be the dominant pathway, although in some cases acetate fermentation contributed up to 50% of the total methane formation rate. High spatial variation, both vertically and horizontally, in methane formation rates are a characteristic feature of this aquifer sediment......‰. The usual interpretation of the stable isotope data would then suggest acetate fermentation to be the dominant pathway for methanogenesis, in conflict with the radiotracer data. However, recent evidence suggests the deuterium content of the groundwater to have a dominant effect on the deuterium content...

  13. Modelling the effects of porous media deformation on the propagation of water-table waves in a sandy unconfined aquifer

    Science.gov (United States)

    Jazayeri Shoushtari, Seyed Mohammad Hossein; Cartwright, Nick

    2016-11-01

    This paper examines the influence of porous media deformation on water-table wave dispersion in an unconfined aquifer using a numerical model which couples Richards' equation to the poro-elastic model. The study was motivated by the findings of Shoushtari et al. (J Hydrol 533:412-440, 2016) who were unable to reproduce the observed wave dispersion in their sand flume data with either numerical Richards' equation models (assuming rigid porous media) or existing analytic solutions. The water-table wave dispersion is quantified via the complex wave number extracted from the predicted amplitude and phase profiles. A sensitivity analysis was performed to establish the influence of the main parameters in the poro-elastic model, namely Young's modulus (E) and Poisson's ratio (ν). For a short oscillation period (T = 16.4 s), the phase lag increase rate (k i) is sensitive to the chosen values of E and ν, demonstrating an inverse relationship with both parameters. Changes in the amplitude decay rate (k r), however, were negligible. For a longer oscillation period (T = 908.6 s), variations in the values of E and ν resulted in only small changes in both k r and k i. In both the short and long period cases, the poro-elastic model is unable to reproduce the observed wave dispersion in the existing laboratory data. Hence porous media deformation cannot explain the additional energy dissipation in the laboratory data. Shoushtari SMH, Cartwright N, Perrochet P, Nielsen P (2016) The effects of oscillation period on groundwater wave dispersion in a sandy unconfined aquifer: sand flume experiments and modelling. J Hydrol 533:412-440.

  14. Modelling the effects of porous media deformation on the propagation of water-table waves in a sandy unconfined aquifer

    Science.gov (United States)

    Jazayeri Shoushtari, Seyed Mohammad Hossein; Cartwright, Nick

    2017-03-01

    This paper examines the influence of porous media deformation on water-table wave dispersion in an unconfined aquifer using a numerical model which couples Richards' equation to the poro-elastic model. The study was motivated by the findings of Shoushtari et al. (J Hydrol 533:412-440, 2016) who were unable to reproduce the observed wave dispersion in their sand flume data with either numerical Richards' equation models (assuming rigid porous media) or existing analytic solutions. The water-table wave dispersion is quantified via the complex wave number extracted from the predicted amplitude and phase profiles. A sensitivity analysis was performed to establish the influence of the main parameters in the poro-elastic model, namely Young's modulus ( E) and Poisson's ratio ( ν). For a short oscillation period ( T = 16.4 s), the phase lag increase rate ( k i) is sensitive to the chosen values of E and ν, demonstrating an inverse relationship with both parameters. Changes in the amplitude decay rate ( k r), however, were negligible. For a longer oscillation period ( T = 908.6 s), variations in the values of E and ν resulted in only small changes in both k r and k i. In both the short and long period cases, the poro-elastic model is unable to reproduce the observed wave dispersion in the existing laboratory data. Hence porous media deformation cannot explain the additional energy dissipation in the laboratory data. Shoushtari SMH, Cartwright N, Perrochet P, Nielsen P (2016) The effects of oscillation period on groundwater wave dispersion in a sandy unconfined aquifer: sand flume experiments and modelling. J Hydrol 533:412-440.

  15. Hydrodynamic influences of tidal fluctuations and beach slopes on benzene transport in unconfined, sandy costal aquifers

    Science.gov (United States)

    Ni, C.-F.; Wei, Y.-M.

    2012-04-01

    Oil spills in oceans have led to severe environment and ecosystem problems due to high toxicity substances, large spatial extents, and long temporal durations. The BTEX compounds are key indexes generally used for identifications of such contamination events and also for quantifications of residual substances after remediations. Benzene is one of the BTEX compounds, which is recognized to be high toxicity and may threat near-shore ecosystem and human safety. Therefore, the understanding of benzene transport in costal aquifers is critical for predictions of contaminated zones and managements and organizations of remediation plans. In this study a numerical investigation was conducted to quantify the influence of tidal fluctuations and beach slopes on benzene transport in an unconfined coastal aquifer. More specifically, three different tidal amplitudes and three beach slopes were considered in the two-dimensional HYDROGEOCHEM model to characterize the spatial and temporal behavior of the benzene transport. Simulation results show that tidal fluctuations will lead to shallow seawater circulations near the ground surface where the high tides can reach periodically. Such local circulation flows will trap benzene plume and the plume may migrate to the deeper aquifer, depending on the amplitudes of tides and the surface slopes of the coastal lines. The sine curve tides with 0.5 m amplitudes will create circulation plume sizes of about 50m in length and 20m in depth, while the circulation plume sizes for tides with 1.0 m amplitudes will significantly increase to approximately 150 m in length and 60 m in depth. Additionally, double the beach slopes and keep the same tidal amplitude will lead to 40 m plume movement toward the land. The amplitude of tidal fluctuation is the key factor to decide when and where a benzene plume reaches a largest depth. In general, the plume with tidal amplitude of 0.5 m requires 50 days to reach 90% of the largest depth. However, the plume with

  16. Nutrient Discharge Beneath Urban Lawns To A Sandy Coastal Aquifer, Perth, Western Australia

    Science.gov (United States)

    Sharma, M. L.; Herne, D. E.; Byrne, J. D.; Kin, P. G.

    1996-01-01

    Excess nitrogen and phosphorus leaching beneath urban lawns on sandy soils in metropolitan Perth, Western Australia, may pose a serious threat not only to the quality of the underlying groundwater but also to many surface-water bodies. In this study, suction-driven lysimeters were developed and used to quantify water and nutrient fluxes below the root zone at four urban lawn sites in Perth. The four sites received similar fertiliser treatment but differed in irrigation regimes. Over a period of 12 months, up to 51 percent of incident water passed below the root zone. Annual flow-weighted concentrations of NO3-N in the leachate ranged from 0.8-5.4 mg/L, whereas PO4-P concentrations ranged from 0.003-0.034 mg/L. At most sites, NO3-N concentrations periodically equalled or exceeded the World Health Organization (WHO) drinking-water limit of 10 mg/L; high concentration were maintained for longer periods at two sites with coarser sands and high irrigation regimes. Evidence exists that concentrations of N and P in urban groundwater are reduced through dilution and possibly through chemical transformation and adsorption. It is unlikely that NO3-N concentrations in groundwater will exceed the WHO drinking limit except for relatively short periods of time. However, nutrients (especially N) from fertilised lawns are a threat to wetlands and waterways into which nutrient-rich groundwater is discharged. Modified management practices for urban lawns, or alternative-style home gardens may need to be developed in order to minimise nutrient enrichment of groundwater and water bodies. Some suggestions for these are presented.

  17. Sorption of benzothiazoles onto sandy aquifer material under equilibrium and nonequlibrium conditions

    Directory of Open Access Journals (Sweden)

    Kragulj Marijana M.

    2014-01-01

    Full Text Available In this study, the sorption behaviour of 1,3-benzothiazole (BT and 2-(methylthiobenzothiazole (MTBT was investigated on Danube geosorbent under equilibrium and nonequilibrium conditions. All sorption isotherms fitted well with the Freundlich model (R2=0.932-0.993. The results showed that organic matter of the Danube geosorbent has a higher sorption affinity for the more hydrophobic MTBT compared to BT. However, sorption-desorption experiments showed that MTBT was more easily desorbed than BT molecules, which indicates the importance of absorption relative to adsorption in the overall sorption mechanism of MTBT. In general, molecules of BT and MTBT were more easily desorbed in the lower concentration range, which resulted in an increase in the hysteresis indices with increasing concentrations. Column experiments revealed that retention of the investigated compounds on the aquifer material followed the compound’s hydrophobicity. BT showed a lower retention, in accordance with its lower sorption affinity obtained in the static experiments, while MTBT showed a greater sorption affinity, and thus had a longer retention time on the column. Thus during transport BT represent greater risk for groundwaters than MTBT. These results have increased our understanding of benzothiazoles sorption and desorption process which represent one of the most important factors which influence the behaviour of organic compounds in the environment.

  18. Swash-Induced Infiltration in a Sandy Beach Aquifer, Cape Henlopen, Delaware

    Science.gov (United States)

    Heiss, J.; Ullman, W. J.; Michael, H. A.

    2011-12-01

    Submarine groundwater discharge has been shown to be an important source of nutrients, heavy metals, and organic compounds to the coastal ocean. Physical flow and mixing dynamics in the intertidal zone may influence these contaminant fluxes; however the mechanisms that contribute to mixing of saltwater and through-flowing freshwater are not well understood. A study of wave swash-induced infiltration at two sites on Cape Henlopen, Delaware, was performed to quantify effects of swash zone width and tidal elevation on the flux of seawater into the beach aquifer. Porewater salinity measurements indicate the presence of a well-defined intertidal freshwater-seawater mixing zone. High-frequency pressure and soil moisture measurements from shore-perpendicular arrays across the beachface were used to infer influx rates. Measurements were conducted at two sites, one with larger waves and a wide swash zone, and the other with smaller waves and a narrow swash zone. Infiltration occurred during the rising tide at the leading edge of the swash zone and increased in magnitude from low tide to high tide. Infiltration rates were on average 2.2 times greater near mean high water than near mean low water. Measurements revealed that swash zone width influences infiltration: influx rates associated with the beach with a wider swash zone were 2.7 times higher than those of a beach with a narrower swash zone. The field observations are roughly consistent with estimates from analytical models, which are highly sensitive to uncertain model parameters. Pressure measurements during rising tide also indicate changes in hydraulic gradients due to infiltrated seawater. Flow beneath the sensor array was initially seaward and as the swash zone tracked up the beachface, a groundwater mound formed that resulted in net landward flow in the vicinity of the sensor array. The results demonstrate the role of wave swash in driving beach seawater infiltration, indicate spatial trends in flux across the

  19. Investigation of pharmaceutical transport in saturated sandy aquifers using column experiments: the effect of pH

    Science.gov (United States)

    Börnick, Hilmar; Boxberger, Norman; Licha, Tobias; Worch, Eckhard

    2010-05-01

    Due to the development of advanced analytical techniques it is increasingly known that a high number of polar organic trace compounds, particularly residues of pharmaceuticals, occur in the aquatic environment. In contrast to the sources and pathways of such compounds, their impact on ecosystems and their fate in different environmental compartments are comparatively less investigated. Because of the spatial extension and time available, the zone between water and natural solids (e.g. sediments or soil in groundwater zones, bank filtration sites and for soil aquifer treatment) plays an important role in the elimination of anthropogenic trace compounds from water phase. Here, degradation and sorption processes mainly influence the content of trace compounds. Correlations, specific for compound groups, between n-octanol-water distribution coefficients, available from experiment or calculations, and sorption coefficients (e.g. KOC) often allow a suitable prognosis of the transport behavior of organic pollutants in an underground passage. In case of polar, ionizable organic compounds such prediction is problematic and often not possible. Here, besides relatively weak non-polar van der Waals attraction, other interaction mechanisms, such as covalent bonding, complex formation, or ion exchange, can dominate. The latter is closely connected with the type of basic and/or acid groups in a molecule. The degree of protonation could be changed in dependence of type and concentration of other ions and of the acidity constants (pKa) and therefore from pH. Laboratory column studies at different pH value (range from 4 to 8) were carried out using natural sandy sediments from aquifers and model water containing selected pharmaceuticals to investigate the influence of degree of protonation on sorption. Eight different pharmaceuticals were chosen for laboratory column experiments. Their selection was based on the presence of basic/acid functional groups, pKa, high production and

  20. Identification of TCE and PCE sorption and biodegradation parameters in a sandy aquifer for fate and transport modelling: batch and column studies.

    Science.gov (United States)

    Kret, E; Kiecak, A; Malina, G; Nijenhuis, I; Postawa, A

    2015-07-01

    The main aim of this study was to determine the sorption and biodegradation parameters of trichloroethene (TCE) and tetrachloroethene (PCE) as input data required for their fate and transport modelling in a Quaternary sandy aquifer. Sorption was determined based on batch and column experiments, while biodegradation was investigated using the compound-specific isotope analysis (CSIA). The aquifer materials medium (soil 1) to fine (soil 2) sands and groundwater samples came from the representative profile of the contaminated site (south-east Poland). The sorption isotherms were approximately linear (TCE, soil 1, K d = 0.0016; PCE, soil 1, K d = 0.0051; PCE, soil 2, K d = 0.0069) except for one case in which the best fitting was for the Langmuir isotherm (TCE, soil 2, K f = 0.6493 and S max = 0.0145). The results indicate low retardation coefficients (R) of TCE and PCE; however, somewhat lower values were obtained in batch compared to column experiments. In the column experiments with the presence of both contaminants, TCE influenced sorption of PCE, so that the R values for both compounds were almost two times higher. Non-significant differences in isotope compositions of TCE and PCE measured in the observation points (δ(13)C values within the range of -23.6 ÷ -24.3‰ and -26.3 ÷-27.7‰, respectively) indicate that biodegradation apparently is not an important process contributing to the natural attenuation of these contaminants in the studied sandy aquifer.

  1. Snake River Plain Basin-fill aquifer system

    Data.gov (United States)

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

  2. Laboratory investigations on the role of sediment surface and ground water chemistry in transport of bacteria through a contaminated Sandy Aquifer

    Science.gov (United States)

    Scholl, M.A.; Harvey, R.W.

    1992-01-01

    The effects of pH and sediment surface characteristics on sorption of indigenous groundwater bacteria were determined using contaminated and uncontaminated aquifer material from Cape Cod, MA. Over the pH range of the aquifer (5-7), the extent of bacterial sorption onto sediment in uncontaminated groundwater was strongly pH-dependent, but relatively pH-insensitive in contaminated groundwater from the site. Bacterial sorption was also affected by the presence of oxyhydroxide coatings (iron, aluminum, and manganese). Surface coating effects were most pronounced in uncontaminated groundwater (pH 6.4 at 10??C). Desorption of attached bacteria (up to 14% of the total number of labeled cells added) occurred in both field and laboratory experiments upon adjustment of groundwater to pH 8. The dependence of bacterial sorption upon environmental conditions suggests that bacterial immobilization could change substantially over relatively short distances in contaminated, sandy aquifers and that effects caused by changes in groundwater geochemistry can be significant.

  3. Nitrate in aquifers beneath agricultural systems.

    Science.gov (United States)

    Burkart, M R; Stoner, J D

    2007-01-01

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

  4. Effects of biodegradation of mecoprop, dichlorprop and bentazone by changing the redox conditions from anaerobic to aerobic in sandy aquifer

    DEFF Research Database (Denmark)

    Levi, Suzi; Bjerg, Poul Løgstrup; Albrechtsen, Hans-Jørgen

    2011-01-01

    in combination with geological variations may affect microbial degradation processes by mixing in even low oxygen concentrations and create steep gradients and drastic redox zones in aquifers. The aim of the current study was to investigate the stimulation of pesticides biodegradation by adding oxygen...... knowledge, this is the first observation of bentazone degradation with aquifer. Optimization of redox conditions from anaerobic to aerobic by adding oxygen stimulated the biodegradation of three pesticides.......Pesticides and metabolites are detected in an increasing number of aquifers resulting in closure of many drinking water wells. The natural redox conditions of aquifers are considered to be one of the important factors governing the pesticides degradation in groundwater. Water abstraction strategy...

  5. Hydrogeology and water quality of the Dublin and Midville aquifer systems at Waynesboro, Burke County, Georgia, 2011

    Science.gov (United States)

    Gonthier, Gerard

    2013-01-01

    The hydrogeology and water quality of the Dublin and Midville aquifer systems were characterized in the City of Waynesboro area in Burke County, Georgia, based on geophysical and drillers’ logs, flowmeter surveys, a 24-houraquifer test, and the collection and chemical analysis of water samples in a newly constructed well. At the test site, the Dublin aquifer system consists of interlayered sands and clays between depths of 396 and 691 feet, and the Midville aquifer system consists of a sandy clay layer overlying a sand and gravel layer between depths of 728 and 936 feet. The new well was constructed with three screened intervals in the Dublin aquifer system and four screened intervals in the Midville aquifer system. Wellbore-flowmeter testing at a pumping rate of 1,000 gallons per minute indicated that 52.2 percent of the total flow was from the shallower Dublin aquifer system with the remaining 47.8 percent from the deeper Midville aquifer system. The lower part of the lower Midville aquifer (900 to 930 feet deep), contributed only 0.1 percent of the total flow. Hydraulic properties of the two aquifer systems were estimated using data from two wellbore-flowmeter surveys and a 24-hour aquifer test. Estimated values of transmissivity for the Dublin and Midville aquifer systems were 2,000 and 1,000 feet squared per day, respectively. The upper and lower Dublin aquifers have a combined thickness of about 150 feet and the horizontal hydraulic conductivity of the Dublin aquifer system averages 10 feet per day. The upper Midville aquifer, lower Midville confining unit, and lower Midville aquifer have a combined thickness of about 210 feet, and the horizontal hydraulic conductivity of the Midville aquifer system averages 6 feet per day. Storage coefficient of the Dublin aquifer system, computed using the Theis method on water-level data from one observation well, was estimated to be 0.0003. With a thickness of about 150 feet, the specific storage of the Dublin aquifer

  6. A 3-D numerical model of the influence of meanders on groundwater discharge to a gaining stream in an unconfined sandy aquifer

    Science.gov (United States)

    Balbarini, Nicola; Boon, Wietse M.; Nicolajsen, Ellen; Nordbotten, Jan M.; Bjerg, Poul L.; Binning, Philip J.

    2017-09-01

    Groundwater discharge to streams depends on stream morphology and groundwater flow direction, but are not always well understood. Here a 3-D groundwater flow model is employed to investigate the impact of meandering stream geometries on groundwater discharge to streams in an unconfined and homogenous sandy aquifer at the reach scale (10-200 m). The effect of meander geometry was examined by considering three scenarios with varying stream sinuosity. The interaction with regional groundwater flow was examined for each scenario by considering three groundwater flow directions. The sensitivity of stream morphology and flow direction to other parameters was quantified by varying the stream width, the meander amplitude, the magnitude of the hydraulic gradient, the hydraulic conductivity, and the aquifer thickness. Implications for a real stream were then investigated by simulating groundwater flow to a stream at a field site located in Grindsted, Denmark. The simulation of multiple scenarios was made possible by the employment of a computationally efficient coordinate transform numerical method. Comparison of the scenarios showed that the geometry of meanders greatly affect the spatial distribution of groundwater flow to streams. The shallow part of the aquifer discharges to the outward pointing meanders, while deeper groundwater flows beneath the stream and enters from the opposite side. The balance between these two types of flow depends on the aquifer thickness and meander geometry. Regional groundwater flow can combine with the effect of stream meanders and can either enhance or smooth the effect of a meander bend, depending on the regional flow direction. Results from the Grindsted site model showed that real meander geometries had similar effects to those observed for the simpler sinuous streams, and showed that despite large temporal variations in stream discharge, the spatial pattern of flow is almost constant in time for a gaining stream.

  7. 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...

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

    Data.gov (United States)

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

  9. Characteristics of Southern California coastal aquifer systems

    Science.gov (United States)

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

    2009-01-01

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

  10. In-situ metal precipitation in a zinc-aerobic, sandy aquifer by means of biological sulfate reduction

    NARCIS (Netherlands)

    Janssen, G.M.C.M.; Temminghoff, E.J.M.

    2004-01-01

    The applicability of in situ metal precipitation (ISMP) based on bacterial sulfate reduction (BSR) with molasses as carbon source was tested for the immobilization of a zinc plume in an aquifer with highly unsuitable initial conditions (high Eh, low pH, low organic matter content, and low sulfate co

  11. 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....

  12. Aquifers

    Data.gov (United States)

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

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

    Data.gov (United States)

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

  14. Delineation of Holocene-Pleistocene aquifer system in parts of Middle Ganga Plain, Bihar, Eastern India through DC resistivity survey

    Science.gov (United States)

    Ganguli, Shuva Shankha; Singh, Shashikant

    2016-11-01

    The study area forms a part of the Middle Ganga Plain (MGP) and experiences intensive groundwater draft due to domestic, irrigation and industrial purposes. Geoelectrical surveys were carried out in a geomorphic unit of MGP called South Ganga Plain, along the north-south traverse covering a total 50 km stretch. Interpreted results of the total of 17 vertical electrical soundings, carried out, provided information on aquifer and aquitard geometry and sediment nature in different aquifer systems. Bedrock topography is also demarcated along the north-south transect. The estimated dip of massive bedrock is less than 0.5° and dips toward north. The survey results show that a two-tier aquifer system exists in Newer alluvium parts of the study area and it is replaced by a single aquifer system at Older alluvium that occurs under thick clay/sandy clay bed in the southern part. An exponential decay of the aquifer potential is observed from north to south. Paleo channel Sone River is traced and it forms a potential aquifer.

  15. 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.

  16. 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.

  17. Kinetic and mineralogic controls on the evolution of groundwater chemistry and 87Sr/86Sr in a sandy silicate aquifer, northern Wisconsin, USA

    Science.gov (United States)

    Bullen, T.D.; Krabbenhoft, D.P.; Kendall, C.

    1996-01-01

    Substantial flowpath-related variability of 87Sr/86Sr is observed in groundwaters collected from the Trout Lake watershed of northern Wisconsin. In the extensive shallow aquifer composed of sandy glacial outwash, groundwater is recharged either by seepage from lakes or by precipitation that infiltrates the inter-lake uplands. 87Sr/86Sr of groundwater derived mainly as seepage from a precipitation-dominated lake near the head of the watershed decreases with progressive water chemical evolution along its flowpath due primarily to enhanced dissolution of relatively unradiogenic plagioclase. In contrast, 87Sr/86Sr of groundwater derived mainly from precipitation that infiltrates upland areas is substantially greater than that of precipitation collected from the watershed, due to suppression of plagioclase dissolution together with preferential leaching of Sr from radiogenic phases such as K-feldspar and biotite. The results of a column experiment that simulated the effects of changing residence time of water in the aquifer sand indicate that mobile waters obtain relatively unradiogenic Sr, whereas stagnant waters obtain relatively radiogenic Sr. Nearly the entire range of strontium-isotope composition observed in groundwaters from the watershed was measured in the experimental product waters. The constant mobility of water along groundwater recharge flowpaths emanating from the lakes promotes the dissolution of relatively unradiogenic plagioclase, perhaps due to effective dispersal of clay mineral nuclei resulting from dissolution reactions. In contrast, episodic stagnation in the unsaturated zone along the upland recharge flowpaths suppresses plagioclase dissolution, perhaps due to accumulation of clay mineral nuclei on its reactive surfaces. Differences in redox conditions along these contrasting flowpaths probably enhance the observed differences in strontium isotope behavior. This study demonstrates that factors other than the calculated state of mineral saturation

  18. B and Li isotopes as intrinsic tracers for injection tests in aquifer storage and recovery systems

    Energy Technology Data Exchange (ETDEWEB)

    Kloppmann, Wolfram, E-mail: w.kloppmann@brgm.fr [BRGM, French Geological Survey, 3 Av. Claude Guillemin B.P. 6009, F-45000 Orleans (France); Chikurel, Haim [Mekorot National Water Company, Tel Aviv (Israel); Picot, Geraldine [BRGM, French Geological Survey, 3 Av. Claude Guillemin B.P. 6009, F-45000 Orleans (France); Guttman, Joseph [Mekorot National Water Company, Tel Aviv (Israel); Pettenati, Marie [BRGM, French Geological Survey, 3 Av. Claude Guillemin B.P. 6009, F-45000 Orleans (France); Aharoni, Avi [Mekorot National Water Company, Tel Aviv (Israel); Guerrot, Catherine; Millot, Romain; Gaus, Irina [BRGM, French Geological Survey, 3 Av. Claude Guillemin B.P. 6009, F-45000 Orleans (France); Wintgens, Thomas [Rheinisch Westfaelische Technische Hochschule, RWTH, Aachen (Germany)

    2009-07-15

    Boron and Li isotopes have been tested as environmental tracers of treated sewage injected into a sandy aquifer (Shafdan reclamation project, Israel). During a 38 days injection test in a newly dug injection well, a conservative artificial tracer (Br{sup -}) was monitored together with {delta}{sup 11}B and {delta}{sup 7}Li in the injectate, in the unsaturated soil zone (porous cup) and an observation well in the aquifer. In spite of B and Li concentrations in the injectate close to background values, significant shifts of the isotope signatures could be observed over the duration of the injection test. Boron isotope ratios show a breakthrough curve delayed with respect to Br{sup -} breakthrough due to some reversible sorption on the aquifer material. No isotope fractionation was observed in the unsaturated or the saturated zone so that B isotopes can be considered as conservative in the investigated part of the aquifer system. Lithium isotopes are strongly fractionated, probably due to sorption processes. Lithium concentrations point to a Li sink in the system, {delta}{sup 7}Li values vary strongly with a tendency of {sup 7}Li depletion in the liquid phase over the duration of the experiment. This is opposite to the expected preferential sorption of {sup 6}Li onto clay minerals. Boron isotopes reveals a valuable tracer of artificial recharge of freshwaters derived from treated sewage, both for short term tracer tests and for long-term monitoring of artificial recharge, even if in aquifers with higher clay contents, sorption-linked isotope fractionation cannot be excluded. More data are needed on Li isotope fractionation in natural groundwater systems to assess the potential of this tracer as monitoring tool.

  19. Vertical small scale variations of sorption and mineralization of three herbicides in subsurface limestone and sandy aquifer

    DEFF Research Database (Denmark)

    Janniche, Gry Sander; Mouvet, C.; Albrechtsen, Hans-Jørgen

    2011-01-01

    acetochlor and isoproturon sorption increased substantially with depth; in average 78% (acetochlor) and 61% (isoproturon) per 5 cm. Also the number of acetochlor and isoproturon degraders (mostprobable-number) was higher in the bottom half of the aquifer section (93->16 000 /g) than in the upper half (4......-71 /g). One 50 cm long limestone section with a distinct shift in color showed a clear shift in mineralization, number of degraders and sorption: In the two brown, uppermost samples, up to 31% mecoprop and up to 9% isoproturon was mineralized during 231 days, the numbers of mecoprop and isoproturon...... degraders were 1 300 to >16 000 /g, and the sorption of both isoproturon and acetochlor was more than three times higher, compared to the two deeper, grayish samples just below where mineralization (≤4 %) and numbers of degraders (1-520 /g) were low for all three herbicides. In both unsaturated limestone...

  20. Column studies on transport of deicing additive benzotriazole in a sandy aquifer and a zerovalent iron barrier.

    Science.gov (United States)

    Jia, Yu; Breedveld, Gijs D; Aagaard, Per

    2007-11-01

    Benzotriazole (BTA), a chemical with wide industrial applications, is a typical additive in deicer/anti-icer used at airport. To achieve a better understanding of the transport behaviour and environmental fate of BTA, laboratory column studies have been performed on subsoil samples from Oslo Airport, Gardermoen. To explore possibilities for aquifer remediation, BTA behaviour was also studied in a column of granular zerovalent iron (Fe(0)). The subsoil column study demonstrates a very limited retardation of BTA. Consecutive loadings of BTA of the subsoil column showed no change of the break-through curve (BTC) and complete desorption was observed. The sorption behaviour of BTA to metallic iron (Fe(0)) was rather complex. Considerable retardation was observed in the Fe(0) column and repeated BTA loading resulted in an earlier break-through. Between 20% and 50% of the input concentration was retained permanently in the iron (Fe(0)) column. The BTA sorption to metallic iron was found to be enhanced by chloride which lowered the break-through concentration (i.e the C/C(0) plateau). The fraction of BTA remaining in the iron column was found to vary with the flow rate, indicating a time dependant multilayer sorption mechanism. The steady increase in the amount of adsorbed BTA to the iron column during loading corresponds to a rather strong bonding of 4-15 BTA layers to the iron surface. A very slow desorption of BTA was observed; even after flushing with 753 pore volumes of BTA free water, 7.5% of the BTA remained in the column. A geochemical model was developed based on PHREEQC-2 to simulate the sorption and transport of BTA in the tested materials. The BTA sorption was modelled with Freundlich sorption isotherms, as earlier determined in batch experiments. A slight adjustment of the Freundlich parameters was required to fit the observed column break-through. However, our model was not able to simulate the long-term retainment of BTA in the granular iron columns. The

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

    Science.gov (United States)

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

    2017-05-01

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

  2. Application of isotopic tracers as a tool for understanding hydrodynamic behavior of the highly exploited Diass aquifer system (Senegal)

    Science.gov (United States)

    Madioune, Diakher Hélène; Faye, Serigne; Orban, Philippe; Brouyère, Serge; Dassargues, Alain; Mudry, Jacques; Stumpp, Christine; Maloszewski, Piotr

    2014-04-01

    The Diass horst aquifer system located 50 km east of Dakar (Senegal) is exploited in two main aquifers covered by a sandy superficial aquifer: the confined/unconfined Palaeocene karstic limestone and the confined Maastrichtian sandstone aquifer underneath. This system has experienced intensive groundwater abstraction during the last 50 years to supply increasing water demand, agricultural and industrial needs. The high abstraction rate from 1989 to 2009 (about 109,000 m3/d) has caused a continuous groundwater level decline (up to 30 m), a modification of the groundwater flow and salinization in parts of the aquifers. The objective of the study is to improve our understanding of the system functioning with regards to high pumping, identify the geochemical reactions that take place in the system, infer origin and timing of recharge by using mainly stable (δ18O, δ2H, 13C) and radioactive (3H and 14C) isotopes. Water types defined in the Piper diagram vary in order of abundance from Ca-HCO3 (65%), Ca/Na-Cl (20%), Na-HCO3 (3%) and Na-Cl (12%). Values of δ18O and δ2H for the superficial aquifer range between -5.8 and -4.2‰ and between -42 and -31‰, respectively. For the Palaeocene aquifer they range from -5.8 to -5.0‰ and from -38 to -31‰, respectively; values in the Maastrichtian aquifer are between -5.9 and -4.3‰ for δ18O and -38 to -26‰ for δ2H. Plotted against the conventional δ18O vs δ2H diagram, data from the upper aquifer exhibit a dispersed distribution with respect to isotopic fractionation while those of the Palaeocene and Maastrichtian aquifers are aligned parallel and slightly below/or on the Global Meteoric Water Line (GMWL) evidencing ancient waters which had evaporated during infiltration. The low tritium (generally tritium (1.2-4.3 TU) and 14C (65.7-70.8 pmc) values indicate some mixture with recent water likely through faulting and vertical drainage from the upper to deeper aquifers as well as lateral flow along flow paths to the

  3. Differential effects of dissolved organic carbon upon re-entrainment and surface properties of groundwater bacteria and bacteria-sized microspheres during transport through a contaminated, sandy aquifer

    Science.gov (United States)

    Harvey, R.W.; Metge, D.W.; Mohanram, A.; Gao, X.; Chorover, J.

    2011-01-01

    Injection-and-recovery studies involving a contaminated, sandy aquifer (Cape Cod, Massachusetts) were conducted to assess the relative susceptibility for in situ re-entrainment of attached groundwater bacteria (Pseudomonas stuzeri ML2, and uncultured, native bacteria) and carboxylate-modified microspheres (0.2 and 1.0 ??m diameters). Different patterns of re-entrainment were evident for the two colloids in response to subsequent injections of groundwater (hydrodynamic perturbation), deionized water (ionic strength alteration), 77 ??M linear alkylbenzene sulfonates (LAS, anionic surfactant), and 76 ??M Tween 80 (polyoxyethylene sorbitan monooleate, a very hydrophobic nonionic surfactant). An injection of deionized water was more effective in causing detachment of micrsopheres than were either of the surfactants, consistent with the more electrostatic nature of microsphere's attachment, their extreme hydrophilicity (hydrophilicity index, HI, of 0.99), and negative charge (zeta potentials, ??, of -44 to -49 mv). In contrast, Tween 80 was considerably more effective in re-entraining the more-hydrophobic native bacteria. Both the hydrophilicities and zeta potentials of the native bacteria were highly sensitive to and linearly correlated with levels of groundwater dissolved organic carbon (DOC), which varied modestly from 0.6 to 1.3 mg L-1. The most hydrophilic (0.52 HI) and negatively charged (?? -38.1 mv) indigenous bacteria were associated with the lowest DOC. FTIR spectra indicated the latter community had the highest average density of surface carboxyl groups. In contrast, differences in groundwater (DOC) had no measurable effect on hydrophilicity of the bacteria-sized microspheres and only a minor effect on their ??. These findings suggest that microspheres may not be very good surrogates for bacteria in field-scale transport studies and that adaptive (biological) changes in bacterial surface characteristics may need to be considered where there is longer

  4. New land-based method for surveying sandy shores and extracting DEMs: the INSHORE system.

    Science.gov (United States)

    Baptista, Paulo; Cunha, Telmo R; Matias, Ana; Gama, Cristina; Bernardes, Cristina; Ferreira, Oscar

    2011-11-01

    The INSHORE system (INtegrated System for High Operational REsolution in shore monitoring) is a land-base survey system designed and developed for the specific task of monitoring the evolution in time of sandy shores. This system was developed with two main objectives: (1) to produce highly accurate 3D coordinates of surface points (in the order of 0.02 to 0.03 m); and (2) to be extremely efficient in surveying a beach stretch of several kilometres. Previous tests have demonstrated that INSHORE systems fulfil such objectives. Now, the usefulness of the INSHORE system as a survey tool for the production of Digital Elevation Models (DEMs) of sandy shores is demonstrated. For this purpose, the comparison of DEMs obtained with the INSHORE system and with other relevant survey techniques is presented. This comparison focuses on the final DEM accuracy and also on the survey efficiency and its impact on the costs associated with regular monitoring programmes. The field survey method of the INSHORE system, based on profile networks, has a productivity of about 30 to 40 ha/h, depending on the beach surface characteristics. The final DEM precision, after interpolation of the global positioning system profile network, is approximately 0.08 to 0.12 m (RMS), depending on the profile network's density. Thus, this is a useful method for 3D representation of sandy shore surfaces and can permit, after interpolation, reliable calculations of volume and other physical parameters.

  5. Superstorm Sandy: Implications For Designing A PostCyber Attack Power Restoration System

    Science.gov (United States)

    2016-03-31

    the grid and other man-made threats. Differences among the industrial control systems (ICSs) utilities use to manage their operations pose an...and control sensors on which utilities rely to provide reliable and resilient service. Major utilities typically use energy management systems...storm’s likely path. By providing timely and accurate forecasts to emergency managers 74 FEMA, Hurricane Sandy FEMA After-Action Report. 75 US

  6. 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...

  7. Stochastic modeling of a lava-flow aquifer system

    Science.gov (United States)

    Cronkite-Ratcliff, Collin; Phelps, Geoffrey A.

    2014-01-01

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

  8. Source and mobility of Rare Earth Elements in a sedimentary aquifer system: Aquitaine basin (Southern France)

    Science.gov (United States)

    Negrel, P. J.; Petelet-Giraud, E.; Millot, R.; Malcuit, E.

    2011-12-01

    The study of rare earth elements (REEs) in natural waters initially involved an examination of their occurrence and behavior in seawater and coastal waters such as estuaries. Since the 1990s, REE geochemistry has been applied to continental waters such as rivers and lakes and groundwaters. Rare earth elements) are of great interest because of their unique characteristics and have been used in the study of many geological processes like weathering and water-rock interaction processes, provenance of sediments, etc... With the evolution of analytical techniques like new generation ICP-MS, much attention had been paid towards the water geochemistry of REEs. However, there is a need of more investigations devoted to REEs in large groundwater systems, especially on the understanding of the distribution of REEs and their evolution in such systems. In this frame, large sedimentary aquifer systems often constitute strategic water resources for drinking water supply, agriculture irrigation and industry, but can also represent an energetic resource for geothermal power. Large water abstractions can induce complete modification of the natural functioning of such aquifer systems. These large aquifer systems thus require water management at the basin scale in order to preserve both water quantity and quality. The large Eocene Sand aquifer system of the Aquitaine sedimentary basin was studied through various hydrological, chemical and isotopic tools. This system extends over 116,000 km2 in the South west part of the French territory. The aquifer being artesian in the west of the district and confined with piezometric levels around 250-m depth in the east. The 'Eocene Sands', composed of sandy Tertiary sediments alternating with carbonate deposits, is a multi-layer system with high permeability and a thickness of several tens of metres to a hundred metres. The Eocene Sand aquifer system comprises at least five aquifers: Paleocene, Eocene infra-molassic sands (IMS), early Eocene

  9. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia

    Directory of Open Access Journals (Sweden)

    WAHYU ASTIKO

    2016-01-01

    Full Text Available Abstract. Astiko W, Fauzi MT, Sukartono. 2016. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia. Nusantara Bioscience 8: 66-70. Inoculation of arbuscular mycorrhizal fungi (AMF on maize in sandy soil is expected to have positive implications for the improvement of AMF population and nutrient uptake. However, how many increases in the AMF population and nutrient uptake in the second cycle of a certain cropping system commonly cultivated by the farmers after growing their corn crop have not been examined. Since different cropping systems would indicate different increases in the populations of AMF and nutrient uptake. This study aimed to determine the population AMF and nutrient uptake on the second cropping cycle of corn-based cropping systems which utilized indigenous mycorrhizal fungi on sandy soil in dryland area of North Lombok, West Nusa Tenggara, Indonesia. For that purpose, an experiment was conducted at the Akar-Akar Village in Bayan Sub-district of North Lombok, designed according to the Randomized Complete Block Design, with four replications and six treatments of cropping cycles (P0 = corn-soybean as a control, in which the corn plants were not inoculated with AMF; P1 = corn-soybean, P2 = corn-peanut, P3 = corn-upland rice, P4 = corn-sorghum, and P5 = corn-corn, in which the first cycle corn plants were inoculated with AMF. The results indicated that the mycorrhizal populations (spore number and infection percentage were highest in the second cycle sorghum, achieving 335% and 226% respectively, which were significantly higher than those in the control. Increased uptake of N, P, K and Ca the sorghum plants at 60 DAS of the second cropping cycle reached 200%; 550%; 120% and 490% higher than in the control. The soil used in this experiment is rough-textured (sandy loam, so it is relatively low in water holding capacity and high porosity.

  10. 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

  11. 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.

  12. 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

  13. 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

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

    Science.gov (United States)

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

    2016-12-01

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

  15. Hydrology of the Texas Gulf Coast aquifer systems

    Science.gov (United States)

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

    1991-01-01

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

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

    Indian Academy of Sciences (India)

    Mo-Hsiung Chuang; Hund-Der Yeh

    2011-12-01

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

  17. Analyzing Hurricane Sandy

    Science.gov (United States)

    Convertino, Angelyn; Meyer, Stephan; Edwards, Becca

    2015-03-01

    Post-tropical Storm Sandy underwent extratropical transition shortly before making landfall in southern New Jersey October 29 2012. Data from this system was compared with data from Hurricane Ike (2008) which represents a classic hurricane with a clear eye wall and symmetry after landfall. Storm Sandy collided with a low pressure system coming in from the north as the hurricane made landfall on the US East coast. This contributed to Storm Sandy acting as a non-typical hurricane when it made landfall. Time histories of wind speed and wind direction were generated from data provided by Texas Tech's StickNet probes for both storms. The NOAA Weather and Climate program were used to generate radar loops of reflectivity during the landfall for both storms; these loops were compared with time histories for both Ike and Sandy to identify a relationship between time series data and storm-scale features identified on radar.

  18. Hydrogeochemical and mineralogical effects of sustained CO2 contamination in a shallow sandy aquifer: A field-scale controlled release experiment

    DEFF Research Database (Denmark)

    Cahill, Aaron Graham; Marker, Pernille Aabye; Jakobsen, Rasmus

    2014-01-01

    A shallow aquifer CO2 contamination experiment was performed to investigate evolution of water chemistry and sediment alteration following leakage from geological storage by physically simulating a leak from a hypothetical storage site. In a carbonate-free aquifer, in western Denmark, a total...... of 1600 kg of gas phase CO2 was injected at 5 and 10 m depth over 72 days through four inclined injection wells into aeolian and glacial sands. Water chemistry was monitored for pH, EC, and dissolved element evolution through an extensive network of multilevel sampling points over 305 days. Sediment cores...... injection of CO2 into shallow potable aquifer studied Water chemistry monitored over 305 days and effects on sediment investigated Results show distinct chemical development, high Al concentrations, and sediment alteration © 2014. American Geophysical Union. All Rights Reserved....

  19. Abrasive wear based predictive maintenance for systems operating in sandy conditions

    NARCIS (Netherlands)

    Woldman, M.; Tinga, T.; Heide, E. van der; Masen, M.A.

    2015-01-01

    Machines operating in sandy environments are damaged by the abrasive action of sand particles that enter the machine and become entrapped between components and contacting surfaces. In the case of the military services the combination of a sandy environment and the wide range of tasks to be fulfille

  20. Developing a sustainable child and family service system after a community tragedy: Lessons from Sandy Hook.

    Science.gov (United States)

    Hoagwood, Kimberly Eaton; Olin, Su-Chin Serene; Wang, Nicole M; Pollock, Michele; Acri, Mary; Glaeser, Elizabeth; Whitmyre, Emma D; Storfer-Isser, Amy; Horwitz, Sarah McCue

    2017-08-01

    This paper describes a systematic approach to assessing community services post-Sandy Hook shooting. An evaluation team was invited to develop a sustainability plan for community services in Newtown. Service organizations, providers and families were interviewed. Descriptive statistics were used to characterize the range of services; respondent perspectives were coded using content analysis. We found that Newtown has a broad array of community services, but respondent groups varied in their perceptions of service adequacy. Consensus existed about core components of an ideal service system, including centralizing access; coordinating care; personalizing and tailoring services for families; and providing evidence-based care. The strategic community assessment approach developed here may inform how communities examine their service capacity and develop sustainability plans post-disaster.

  1. Evaluation of a LIDAR Land-Based Mobile Mapping System for Monitoring Sandy Coasts

    Directory of Open Access Journals (Sweden)

    A. Pieter Van Waarden

    2011-07-01

    Full Text Available The Dutch coast is characterized by sandy beaches flanked by dunes. Understanding the morphology of the coast is essential for defense against flooding of the hinterland. Because most dramatic changes of the beach and the first dune row happen during storms, it is important to assess the state of the coast immediately after a storm. This is expensive and difficult to organize with Airborne Laser Scanning (ALS. Therefore, the performance of a Land-based Mobile Mapping System (LMMS in mapping a stretch of sandy Dutch coast of 6 km near the municipality of Egmond is evaluated in this research. A test data set was obtained by provider Geomaat using the StreetMapper LMMS system. Both the relative quality of laser point heights and of a derived Digital Terrain model (DTM are assessed. First, the height precision of laser points is assessed a priori by random error propagation, and a posteriori by calculating the height differences between close-by points. In the a priori case, the result is a theoretical laser point precision of around 5 cm. In the a posteriori approach it is shown that on a flat beach a relative precision of 3 mm is achieved, and that almost no internal biases exist. In the second analysis, a DTM with a grid size of 1 m is obtained using moving least squares. Each grid point height includes a quality description, which incorporates both measurement precision and terrain roughness. Although some problems remain with the scanning height of 2 m, which causes shadow-effect behind low dunes, it is concluded that a laser LMMS enables the acquisition of a high quality DTM product, which is available within two days.

  2. Influence of Climatic Changes and Human Activities on the Salinization Process of Coastal Aquifer Systems

    Directory of Open Access Journals (Sweden)

    Dimitra Rapti-Caputo

    2010-10-01

    Full Text Available In the present research, two arid coastal zones of the Mediterranean region (mean annual precipitation about 440 mm/a, have been investigated for evaluating the qualitative and quantitative impact of both human activities and climatic changes on the groundwater resources and the hydrological cycle in general. In particular, the hydrographic network of the Akrotiri (Cyprus coastal aquifer system is strongly controlled by engineering handicrafts that have induced a quality worsening of the groundwater resources. Due to over-pumping in the central sector of the area, a lowering of the piezometric level of about 15 m has been observed. As a consequence, a salinization process has occurred in the coastal sector with a mean annual salinization velocity of the salty water front varying between 47 and 97 cm/a (period 1964-1996. Due to the high salinity values, the water is at present unsuitable for irrigation use. The second case study is represented by the alluvial plain of Licata (southern Sicily, Italy, where the evolution of the Salso River (in Italian the name means ’Salty River’ and the coastal dynamics, characterised by repeated marine transgressions and regressions, qualitatively and quantitatively influenced the underground water resources. Also the anthropogenic activities played a crucial role, especially the farming activity as it is largely documented by the occurrence of numerous greenhouses covering most of the plain. The water depth of the unconfined, mainly sandy, aquifer developed in the Quaternary deposits is between 0.3 m and locally 5 m from the surface, while the principal alimentation occurs via infiltration from precipitations and lateral outflow from the Salso River.

  3. Hydrogeophysical methods for analyzing aquifer storage and recovery systems.

    Science.gov (United States)

    Minsley, Burke J; Ajo-Franklin, Jonathan; Mukhopadhyay, Amitabha; Morgan, Frank Dale

    2011-01-01

    Hydrogeophysical methods are presented that support the siting and monitoring of aquifer storage and recovery (ASR) systems. These methods are presented as numerical simulations in the context of a proposed ASR experiment in Kuwait, although the techniques are applicable to numerous ASR projects. Bulk geophysical properties are calculated directly from ASR flow and solute transport simulations using standard petrophysical relationships and are used to simulate the dynamic geophysical response to ASR. This strategy provides a quantitative framework for determining site-specific geophysical methods and data acquisition geometries that can provide the most useful information about the ASR implementation. An axisymmetric, coupled fluid flow and solute transport model simulates injection, storage, and withdrawal of fresh water (salinity ∼500 ppm) into the Dammam aquifer, a tertiary carbonate formation with native salinity approximately 6000 ppm. Sensitivity of the flow simulations to the correlation length of aquifer heterogeneity, aquifer dispersivity, and hydraulic permeability of the confining layer are investigated. The geophysical response using electrical resistivity, time-domain electromagnetic (TEM), and seismic methods is computed at regular intervals during the ASR simulation to investigate the sensitivity of these different techniques to changes in subsurface properties. For the electrical and electromagnetic methods, fluid electric conductivity is derived from the modeled salinity and is combined with an assumed porosity model to compute a bulk electrical resistivity structure. The seismic response is computed from the porosity model and changes in effective stress due to fluid pressure variations during injection/recovery, while changes in fluid properties are introduced through Gassmann fluid substitution.

  4. Hydrogeophysical methods for analyzing aquifer storage and recovery systems

    Energy Technology Data Exchange (ETDEWEB)

    Minsley, B.J.; Ajo-Franklin, J.; Mukhopadhyay, A.; Morgan, F.D.

    2009-12-01

    Hydrogeophysical methods are presented that support the siting and monitoring of aquifer storage and recovery (ASR) systems. These methods are presented as numerical simulations in the context of a proposed ASR experiment in Kuwait, although the techniques are applicable to numerous ASR projects. Bulk geophysical properties are calculated directly from ASR flow and solute transport simulations using standard petrophysical relationships and are used to simulate the dynamic geophysical response to ASR. This strategy provides a quantitative framework for determining site-specific geophysical methods and data acquisition geometries that can provide the most useful information about the ASR implementation. An axisymmetric, coupled fluid flow and solute transport model simulates injection, storage, and withdrawal of fresh water (salinity {approx}500 ppm) into the Dammam aquifer, a tertiary carbonate formation with native salinity approximately 6000 ppm. Sensitivity of the flow simulations to the correlation length of aquifer heterogeneity, aquifer dispersivity, and hydraulic permeability of the confining layer are investigated. The geophysical response using electrical resistivity, time-domain electromagnetic (TEM), and seismic methods is computed at regular intervals during the ASR simulation to investigate the sensitivity of these different techniques to changes in subsurface properties. For the electrical and electromagnetic methods, fluid electric conductivity is derived from the modeled salinity and is combined with an assumed porosity model to compute a bulk electrical resistivity structure. The seismic response is computed from the porosity model and changes in effective stress due to fluid pressure variations during injection/recovery, while changes in fluid properties are introduced through Gassmann fluid substitution.

  5. Geochemistry of the Cambrian-Ordovician aquifer system in the northern Midwest, United States: D in Regional aquifer-system analysis

    Science.gov (United States)

    Siegel, D.I.

    1989-01-01

    Distributions of solutes in aquifers of Cambrian and Ordovician age were studied in Minnesota, Wisconsin, Iowa, Illinois, northwestern Indiana, and northern Missouri to determine the sources of solutes and the probable chemical mechanisms that control regional variations in water quality. This work is part of the Northern Midwest Regional Aquifer-System Analysis project, whose objective is to describe and model the regional hydrogeology of the Cambrian- Ordovician aquifer system in the study region. The data base used included more than 3,000 ground-water-quality analyses from all major aquifers, but especially from the St. Peter, Jordan, and Mount Simon Sandstones and their equivalents. Regional variations in the water chemistry of glacial drift and other sedimentary units that overlie the Cambrian-Ordovician aquifer system in recharge areas in Minnesota, Iowa, Wisconsin, and Illinois were also studied, but to a lesser degree.

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

    Science.gov (United States)

    Gonthier, Gerard J.; Clarke, John S.

    2016-06-02

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

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

    Science.gov (United States)

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

    1997-01-01

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

  8. Detecting a salinity plume in an unconfined sandy aquifer and assessing secondary soil salinization using electromagnetic induction techniques, North Dakota, USA

    Science.gov (United States)

    Hopkins, D. G.; Richardson, J. L.

    1999-08-01

    Land-use changes on the Sheyenne Delta in southeastern North Dakota, USA, have prompted research on impacts to the unconfined Sheyenne Delta aquifer (SDA). This study examines effects of the saline discharge of a flowing artesian well that taps the Dakota aquifer (DAK) on SDA groundwater chemistry and soil salinity. Objectives were to map the saline plume in the SDA using induction techniques, to assess chloride migration in the SDA, and to evaluate induction sensitivity to moderately saline sands. Induction data, collected in a 2.9-ha grid, were compared to 31 soil profiles analyzed for gravimetric moisture, electrical conductivity, and chloride. Soil salinization is widespread, but only 7% of the area meets the 4-dS/m threshold for saline soils. SDA chloride distribution was determined on transects oriented with and perpendicular to the flow path determined from induction readings. Chloride was detected in the aquifer 550 m from the source, indicating a transport rate of 21 m/yr. Complex recharge and discharge patterns and hummocky relief contribute to a wide chloride plume at this site. A mass balance based on soil-water content and chloride concentration shows that only 4% of the chloride from the DAK well remains in the grid volume.

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

    Science.gov (United States)

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

    1988-01-01

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

  10. Monitoring induced denitrification in an artificial aquifer recharge system.

    Science.gov (United States)

    Grau-Martinez, Alba; Torrentó, Clara; Folch, Albert; Domènech, Cristina; Otero, Neus; Soler, Albert

    2014-05-01

    literature ɛN values of -4o and -22o respectively (Aravena and Robertson, 1998; Pauwels et al., 2000). Ongoing denitrification batch experiments will allow us to determine the specific nitrogen and oxygen isotopic fractionation induced by the organic reactive layer, in order to estimate more precisely the extent of denitrification during artificial aquifer recharge. These results confirmed that the reactive layer induces denitrification in the recharge ponds area, proving the usefulness of an isotopic approach to characterize water quality improvement occurring during artificial aquifer recharge. References 1. Aravena, R., Robertson, W.D., 1998. Use of multiple isotope tracers to evaluate denitrification in ground water: Study of nitrate from a large-flux septic system plume. Ground Water, 36(6): 975-982. 2. Pauwels, H., J.C., Kloppmann, W., 2000. Denitrification and mixing in a schist aquifer: Influence on water chemistry and isotopes. Chemical Geology, 168(3-4): 307-324. Acknowledgment This study was supported by the projects CGL2011-29975-C04-01 from the Spanish Government, 2009SGR-00103 from the Catalan Government and ENPI/2011/280-008 from the European Commission. Please fill in your abstract text.

  11. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent lines for permeable zones of the intermediate aquifer system and Brunswick aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

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

    Science.gov (United States)

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

    2012-12-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

    Sacks, Laura A.; Tihansky, Ann B.

    1996-01-01

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

  15. Hydrogeology, ground-water movement, and subsurface storage in the Floridan aquifer system in southern Florida

    Science.gov (United States)

    Meyer, Frederick W.

    1989-01-01

    The Floridan aquifer system of southern Florida is composed chiefly of carbonate rocks that range in age from early Miocene to Paleocene. The top of the aquifer system in southern Florida generally is at depths ranging from 500 to 1,000 feet, and the average thickness is about 3,000 feet. It is divided into three general hydrogeologic units: (1) the Upper Floridan aquifer, (2) the middle confining unit, and (3) the Lower Floridan aquifer. The Upper Floridan aquifer contains brackish ground water, and the Lower Floridan aquifer contains salty ground water that compares chemically to modern seawater. Zones of high permeability are present in the Upper and Lower Floridan aquifers. A thick, cavernous dolostone in the Lower Floridan aquifer, called the Boulder Zone, is one of the most permeable carbonate units in the world (transmissivity of about 2.5 x 107 feet squared per day). Ground-water movement in the Upper Floridan aquifer is generally southward from the area of highest head in central Florida, eastward to the Straits of Florida, and westward to the Gulf of Mexico. Distributions of natural isotopes of carbon and uranium generally confirm hydraulic gradients in the Lower Floridan aquifer. Groundwater movement in the Lower Floridan aquifer is inland from the Straits of Florida. The concentration gradients of the carbon and uranium isotopes indicate that the source of cold saltwater in the Lower Floridan aquifer is seawater that has entered through the karat features on the submarine Miami Terrace near Fort Lauderdale. The relative ages of the saltwater suggest that the rate of inland movement is related in part to rising sea level during the Holocene transgression. Isotope, temperature, and salinity anomalies in waters from the Upper Floridan aquifer of southern Florida suggest upwelling of saltwater from the Lower Floridan aquifer. The results of the study support the hypothesis of circulating relatively modern seawater and cast doubt on the theory that the

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

    Data.gov (United States)

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

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

    Data.gov (United States)

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

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

    Science.gov (United States)

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

    2014-05-01

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

  19. Trends and transformation of nutrients and pesticides in a Coastal Plain aquifer system, United States

    Science.gov (United States)

    Denver, J.M.; Tesoriero, A.J.; Barbaro, J.R.

    2010-01-01

    Four local-scale sites in areas with similar corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] agriculture were studied to determine the effects of different hydrogeologic settings of the Northern Atlantic Coastal Plain (NACP) on the transport of nutrients and pesticides in groundwater. Settings ranged from predominantly well-drained soils overlying thick, sandy surficial aquifers to predominantly poorly drained soils with complex aquifer stratigraphy and high organic matter content. Apparent age of groundwater, dissolved gases, N isotopes, major ions, selected pesticides and degradates, and geochemical environments in groundwater were studied. Agricultural chemicals were the source of most dissolved ions in groundwater. Specific conductance was strongly correlated with reconstructed nitrate (the sum of N in nitrate and N gas) (R2 = 0.81, p Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  20. Estimation of transit times in a Karst Aquifer system using environmental tracers: Application on the Jeita Aquifer system-Lebanon.

    Science.gov (United States)

    Doummar, Joanna; Hamdan, Ahmad

    2016-04-01

    Estimating transit times is essential for the assessment of aquifer vulnerability to contaminants. Groundwater in karst aquifer is assumed to be relatively young due to fast preferential pathways; slow flow components are present in water stored in the fissured matrix. Furthermore, transit times are site specific as they depend on recharge rates, temperatures, elevation, and flow media; saturated and unsaturated zones. These differences create significant variation in the groundwater age in karst systems as the water sampled will be a mix of different water that has been transported through different flow pathways (fissured matrix and conduits). Several methods can be applied to estimate water transit time of an aquifer such as artificial tracers, which provide an estimate for fast flow velocities. In this study, groundwater residence times in the Jeita spring aquifer (Lebanon) were estimated using several environmental tracers such as Chlorofluorocarbons (CFCs), Sulfur Hexafluoride (SF6), Helium-Tritium (3H, 3H- 3He). Additional stable isotope and major ion analysis was performed to characterize water types. Groundwater samples were collected from six different wells in the Jeita catchment area (Jurassic Kesrouane aquifer) as well as from the spring and cave itself. The results are reproducible for the Tritium-Helium method, unlike for the CFC/SF6 methods that yielded poor results due to sampling problems. Tritium concentrations in all groundwater samples show nearly the same concentration (~2.73 TU) except for one sample with relatively lower tritium concentration (~2.26 TU). Ages ranging from 0.07 ± 0.07 years to 23.59 ± 0.00 years were obtained. The youngest age is attributed to the spring/ cave while the oldest ages were obtained in wells tapping the fissured matrix. Neon in these samples showed considerable variations and high delta Ne in some samples indicating high excess air. Four (4) samples showed extreme excess air (Delta-Ne is greater than 70 %) and

  1. Contaminant attenuation by shallow aquifer systems under steady flow

    Science.gov (United States)

    Soltani, S. S.; Cvetkovic, V.

    2017-10-01

    We present a framework for analyzing advection-dominated solute transport and transformation in aquifer systems of boreal catchments that are typically shallow and rest on crystalline bedrock. A methodology is presented for estimating tracer discharge based on particle trajectories from recharge to discharge locations and computing their first passage times assuming that the flow pattern is approximately steady-state. Transformation processes can be included by solving one-dimensional reactive transport with randomized water travel time as the independent variable; the distribution of the travel times incorporates morphological dispersion (due to catchment geometry/topography) as well as macro-dispersion (due to heterogeneity of underlying hydraulic properties). The implementation of the framework is illustrated for the well characterized coastal catchment of Forsmark (Sweden). We find that macro-dispersion has a notable effect on attenuation even though the morphological dispersion is significantly larger. Preferential flow on the catchment scale is found to be considerable with only 5% of the Eulerian velocities contributing to transport over the simulation period of 375 years. Natural attenuation is illustrated as a simple (linear decay) transformation process. Simulated natural attenuation can be estimated analytically reasonably well by using basic hydrological and structural information, the latter being the pathway length distribution and average aquifer depth to the bedrock.

  2. Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer

    Science.gov (United States)

    Harvey, Ronald W.; Metge, David W.; Barber, Larry B.; Aiken, George R.

    2010-01-01

    The effects of a dilute (ionic strength = 5 ?? 10-3 M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 ??g/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only ???3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.

  3. Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer.

    Science.gov (United States)

    Harvey, Ronald W; Metge, David W; Barber, L B; Aiken, George R

    2010-02-01

    The effects of a dilute (ionic strength=5x10(-3)M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 microg/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only approximately 3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.

  4. Using Genetic Algorithm and MODFLOW to Characterize Aquifer System of Northwest Florida (Published Proceedings)

    Science.gov (United States)

    By integrating Genetic Algorithm and MODFLOW2005, an optimizing tool is developed to characterize the aquifer system of Region II, Northwest Florida. The history and the newest available observation data of the aquifer system is fitted automatically by using the numerical model c...

  5. Using Genetic Algorithm and MODFLOW to Characterize Aquifer System of Northwest Florida

    Science.gov (United States)

    By integrating Genetic Algorithm and MODFLOW2005, an optimizing tool is developed to characterize the aquifer system of Region II, Northwest Florida. The history and the newest available observation data of the aquifer system is fitted automatically by using the numerical model c...

  6. Characterising Bedrock Aquifer Systems in Korea Using Paired Water-Level Monitoring Data

    Directory of Open Access Journals (Sweden)

    Jae Min Lee

    2017-06-01

    Full Text Available This study focused on characterising aquifer systems based on water-level changes observed systematically at 159 paired groundwater monitoring wells throughout Korea. Using spectral analysis, principal component analysis (PCA, and cross-correlation analysis with linear regression, aquifer conditions were identified from the comparison of water-level changes in shallow alluvial and deep bedrock monitoring wells. The spectral analysis could identify the aquifer conditions (i.e., unconfined, semi-confined and confined of 58.5% of bedrock wells and 42.8% of alluvial wells: 93 and 68 wells out of 159 wells, respectively. Even among the bedrock wells, 50 wells (53.7% exhibited characteristics of the unconfined condition, implying significant vulnerability of the aquifer to contaminants from the land surface and shallow depths. It appears to be better approach for deep bedrock aquifers than shallow alluvial aquifers. However, significant portions of the water-level changes remained unclear for categorising aquifer conditions due to disturbances in data continuity. For different aquifer conditions, PCA could show typical pattern and factor scores of principal components. Principal component 1 due to wet-and-dry seasonal changes and water-level response time was dominant covering about 55% of total variances of each aquifer conditions, implying the usefulness of supplementary method of aquifer characterisation. Cross-correlation and time-lag analysis in the water-level responses to precipitations clearly show how the water levels in shallow and deep wells correspond in time scale. No significant differences in time-lags was found between shallow and deep wells. However, clear time-lags were found to be increasing from unconfined to confined conditions: from 1.47 to 2.75 days and from 1.78 to 2.75 days for both shallow alluvial and deep bedrock wells, respectively. In combination of various statistical methods, three types of water-level fluctuation

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Arthur Schmidt Nanni

    2013-01-01

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

  9. The influence of fish ponds and salinization on groundwater quality in the multi-layer coastal aquifer system in Israel

    Science.gov (United States)

    Tal, A.; Weinstein, Y.; Yechieli, Y.; Borisover, M.

    2017-08-01

    This study focuses on the impact of surface reservoirs (fish ponds) on a multi aquifer coastal system, and the relation between the aquifer and the sea. The study was conducted in an Israeli Mediterranean coastal aquifer, which includes a sandy phreatic unit and two confined calcareous sandstone units. The geological description is based on 52 wells, from which 33 samples were collected for stable isotope analysis and 25 samples for organic and inorganic parameters. Hydraulic head and chemical measurements suggest that there is an hydraulic connection between the fish ponds above the aquifer and the phreatic unit, whereas the connection with the confined units is very limited. The phreatic unit is characterized by a low concentration of oxygen and high concentrations of ammonium and phosphate, while the confined units are characterized by higher oxygen and much lower ammonium and phosphate concentrations. Organic matter fluorescence was found to be a tool to distinguish the contribution of the pond waters, whereby a pond water signature (characterized by proteinaceous (tryptophan-like) and typical humic-matter fluorescence) was found in the phreatic aquifer. The phreatic unit is also isotopically enriched, similar to pond waters, with δ18O of -1‰ and δD of -4.6‰, indicating enhanced evaporation of the pond water before infiltration, whereas there is a depleted isotopic composition in the confined units (δ18O = -4.3‰, δD = -20.4‰), which are also OM-poor. The Phreeqc model was used for quantitative calculation of the effect of pond losses on the different units. The Dissolved Inorganic Nitrogen (DIN) in the upper unit increases downstream from the ponds toward the sea, probably due to organic matter degradation, suggesting contribution of DIN from shallow groundwater flow to the sea. 87Sr/86Sr and Mg/Ca in the brackish and saline groundwater of the lower confined units increase toward seawater value, suggesting that the salinization process in the region

  10. Historical potentiometric surface of the Edwards-Trinity aquifer system and contiguous hydraulically connected units, west-central Texas

    Science.gov (United States)

    Bush, Peter W.; Ardis, Ann F.; Wynn, Kirby H.

    1993-01-01

    The Edwards-Trinity aquifer system is a sequence of near-surface, hydraulically connected, Cretaceous carbonate and quartzose clastic rocks that underlie about 42,000 mi2 of west-central Texas (fig. 1). The aquifer system is currently (1991) being studied as a part of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program, which is intended to describe the regional hydrogeology of important aquifer systems nationwide.

  11. Evaluation of a LIDAR Land-Based Mobile Mapping System for Monitoring Sandy Coasts

    NARCIS (Netherlands)

    Bitenc, M.; Lindenbergh, R.C.; Khoshelham, K.; Van Waarden, A.P.

    2011-01-01

    The Dutch coast is characterized by sandy beaches flanked by dunes. Understanding the morphology of the coast is essential for defense against flooding of the hinterland. Because most dramatic changes of the beach and the first dune row happen during storms, it is important to assess the state of th

  12. Evaluation of a laser land-based mobile mapping system for monitoring sandy coasts

    NARCIS (Netherlands)

    Bitenc, M.; Lindenbergh, R.C.; Khoshelham, K.; Van Waarden, A.P.

    2010-01-01

    The Dutch coast is characterized by sandy beaches flanked by dunes. Its morphology is essential for the defense against flooding of the hinterland. Therefore it is monitored on a yearly basis by Airborne Laser Scanning (ALS). However, it is recognized that most erosion of the beach and first dune ro

  13. Analysis on responding ability of well-aquifer system to precursors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-liang; LI Yuan-yuan; LI Dong-mei; FAN Xue-fang; ZHAO xiao-yun

    2006-01-01

    Recording number of precursors from fourteen observation wells in Shanxi, Hebei, Beijing and Jiangsu region is analyzed and percentage of recording number of precursors to total number of earthquakes during the statistic years is presented. The relationship between characteristic parameters of well-aquifer system and responding ability to precursors is analyzed by the expression of amplification factor of well-aquifer system induced by Cooper et al. The results indicate that responding ability of well-aquifer system to precursors is related to inherent period of well aquifer, that is to say, the greater the inherent period is, the stronger the ability of recording precursor is. Responding ability of well-aquifer system to precursors is also related to ratio of transmissivity to square of radius of wells, and the greater the ratio is, the stronger the responding ability is.

  14. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent of the sand-and-gravel aquifer of the surficial aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  15. Modeling aquifer systems with analytic elements and subdomains

    Science.gov (United States)

    Fitts, C. R.

    2010-07-01

    A new approach for analytic element (AE) modeling of groundwater flow is presented. The approach divides the modeled region into polygonal subdomains, each with its own analytic flow model and its own local isotropic or anisotropic aquifer parameters. This allows analytic modeling of systems where the anisotropy ratio and direction vary spatially, an AE capability not possible without subdomains. It also allows for flexible layering in a model, with more layers in the area of interest abutting fewer layers in the far field. The approach is demonstrated in a model with seven subdomains and a mix of single-layer and triple-layer areas. Checks of the model indicate that the inter-subdomain boundary conditions can be approximated well, and where the differential equation is approximated (multilayer areas and transient flow), that approximation can be quite accurate.

  16. Ground-water flow and quality in Wisconsin's shallow aquifer system

    Science.gov (United States)

    Kammerer, P.A.

    1995-01-01

    The areal concentration distribution of commonmineral constituents and properties of ground water in Wisconsin's shallow aquifer system are described in this report. Maps depicting the water quality and the altitude of the water table are included. The shallow aquifer system in Wisconsin, composed of unconsolidated sand and gravel and shallow bedrock, is the source of most potable ground-water supplies in the State. Most ground water in the shallow aquifer system moves in local flow systems, but it interacts with regional flow systems in some areas.

  17. 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.

  18. The impact of onsite wastewater disposal systems on groundwater in areas inundated by Hurricane Sandy in New York and New Jersey

    Science.gov (United States)

    Fisher, Irene; Phillips, Patrick; Colella, Kaitlyn; Fisher, Shawn C.; Tagliaferri, Tristen N.; Foreman, William T.; Furlong, Edward T.

    2016-01-01

    Coastal onsite wastewater disposal systems (OWDS) were inundated by Hurricane Sandy's storm tide. This study compares the shallow groundwater quality (nutrients, pharmaceuticals, and hormones) downgradient of OWDS before and after Hurricane Sandy, where available, and establishes a baseline for wastewater influence on groundwater in coastal communities inundated by Hurricane Sandy. Nutrients and contaminants of emerging concern (CECs) were detected in shallow groundwater downgradient of OWDS in two settings along the New Jersey and New York coastlines: 1) a single, centralized OWDS in a park; and 2) multiple OWDS (cesspools) in low-density residential and mixed-use/medium density residential areas. The most frequently detected pharmaceuticals were lidocaine (40%), carbamazepine (36%), and fexofenadine, bupropion, desvenlafaxine, meprobamate, and tramadol (24–32%). Increases in the number and total concentration of pharmaceuticals after Hurricane Sandy may reflect other factors (seasonality, usage) besides inundation, and demonstrate the importance of analyzing for a wide variety of CECs in regional studies.

  19. Hydrogeology and hydrologic conditions of the Ozark Plateaus aquifer system

    Science.gov (United States)

    Hays, Phillip D.; Knierim, Katherine J.; Breaker, Brian K.; Westerman, Drew A.; Clark, Brian R.

    2016-11-23

    The hydrogeology and hydrologic characteristics of the Ozark Plateaus aquifer system were characterized as part of ongoing U.S. Geological Survey efforts to assess groundwater availability across the Nation. The need for such a study in the Ozark Plateaus physiographic province (Ozark Plateaus) is highlighted by increasing demand on groundwater resources by the 5.3 million people of the Ozark Plateaus, water-level declines in some areas, and potential impacts of climate change on groundwater availability. The subject study integrates knowledge gained through local investigation within a regional perspective to develop a regional conceptual model of groundwater flow in the Ozark Plateaus aquifer system (Ozark system), a key phase of groundwater availability assessment. The Ozark system extends across much of southern Missouri and northwestern and north-central Arkansas and smaller areas of southeastern Kansas and northeastern Oklahoma. The region is one of the major karst landscapes in the United States, and karst aquifers are predominant in the Ozark system. Groundwater flow is ultimately controlled by aquifer and confining unit lithologies and stratigraphic relations, geologic structure, karst development, and the character of surficial lithologies and regolith mantle. The regolith mantle is a defining element of Ozark Plateaus karst, affecting recharge, karst development, and vulnerability to surface-derived contaminants. Karst development is more advanced—as evidenced by larger springs, hydraulic characteristics, and higher well yields—in the Salem Plateau and in the northern part of the Springfield Plateau (generally north of the Arkansas-Missouri border) as compared with the southern part of the Springfield Plateau in Arkansas, largely due to thinner, less extensive regolith and purer carbonate lithology.Precipitation is the ultimate source of all water to the Ozark system, and the hydrologic budget for the Ozark system includes inputs from recharge

  20. 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).

  1. Large sedimentary aquifer system and sustainable management: investigations of hydrogeological and geochemical variations in Eocene sand aquifer, south western France

    Science.gov (United States)

    Malcuit, E.; Negrel, P. J.; Petelet-Giraud, E.; Durst, P.

    2010-12-01

    In the sedimentary Aquitaine Basin, the Eocene Sand Aquifer system, mostly confined, represents strategic resources for drinking water, irrigation, gas storage and geothermal resources. Therefore, its quantity and quality issues are essential for the sustainable management in this large region that extends over 116,000 km2 (i.e. one-fifth of the French territory). The Eocene Sand Aquifer system comprises at least five aquifers: Paleocene, Eocene infra-molassic sands, early Eocene, middle Eocene, and late Eocene. The extension and thickness of Eocene aquifer layers and negative confined layers vary throughout the basin, from several tens of metres to a hundred metres. The deposit sequences characterizing the Eocene Aquifer System are progradational westward from detrital deposits to carbonates. Eocene sands and Eocene limestones are hydraulically connected and covered by an aquiclude of up to several hundred metres thick of molassic sediments. The groundwater recharge is assumed to occur through the Eocene outcrops located in the north and north-east, and in the south east in contact with the Montagne Noire as well as by vertical leakage from the upper and lower aquifers. Another recharge is suspected in the south near the Petites Pyrenees. According to isotopic data, both present-day recharge and old recharge (16-35 ky) can be evidenced. The north and south evolutions of the piezometric surface are different. In the north, because of years of pumping, a trough in the potentiometric surface has been formed. The piezometric decline is roughly one meter per year in the depression centre. In the south, the decline of the water table is roughly half a meter per year. Furthermore, in the south part, around two sites of gas storage, significant fluctuations of the potentiometric surface are superimposed to the variations resulting from water abstraction, due to the injection and abstraction of gas. However, a major difficulty for the sustainable management is the lack of

  2. Recovery of injected freshwater from a brackish aquifer with a multiwell system.

    Science.gov (United States)

    Miotliński, Konrad; Dillon, Peter J; Pavelic, Paul; Barry, Karen; Kremer, Sarah

    2014-01-01

    Herein we propose a multiple injection and recovery well system strategically operated for freshwater storage in a brackish aquifer. With the system we call aquifer storage transfer and recovery (ASTR) by using four injection and two production wells, we are capable of achieving both high recovery efficiency of injected freshwater and attenuation of contaminants through adequately long residence times and travel distances within the aquifer. The usual aquifer storage and recovery (ASR) scheme, in which a single well is used for injection and recovery, does not warrant consistent treatment of injected water due to the shorter minimum residence times and travel distances. We tested the design and operation of the system over 3 years in a layered heterogeneous limestone aquifer in Salisbury, South Australia. We demonstrate how a combination of detailed aquifer characterization and solute transport modeling can be used to maintain acceptable salinity of recovered water for its intended use along with natural treatment of recharge water. ASTR can be used to reduce treatment costs and take advantage of aquifers with impaired water quality that might locally not be otherwise beneficially used.

  3. MODFLOW-NWT model of a hypothetical stream-aquifer system to assess capture map bias

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A MODFLOW-NWT (version 1.0.9) model of a hypothetical stream-aquifer system is presented for the evaluation and characterization of capture map bias. The...

  4. Estimated Thickness of Quaternary Sediment in the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated thickness of Quaternary sediment of the Wood River Valley aquifer system. This isopach map was constructed by subtracting the estimated...

  5. Management of a Karoo fractured-rock aquifer system – Kalkveld ...

    African Journals Online (AJOL)

    2005-01-21

    Jan 21, 2005 ... Due to large-scale development of groundwater resources for irrigation purposes the Kalkveld area .... Detailed geological assessment of Karoo formations has ..... In order to investigate an aquifer system in a changing time.

  6. Characterization of flow dynamics and vulnerability in a coastal aquifer system.

    Science.gov (United States)

    Murgulet, Dorina; Tick, Geoffrey R

    2013-01-01

    Traditional aquifer vulnerability techniques primarily rely on spatial property data for a region and are limited by their ability to directly or indirectly assess flow and transport processes occurring from the surface to depth within an aquifer system. The main objective of this study was to investigate groundwater vulnerability in terms of aquifer interconnectivity and flow dynamics. A combination of stable isotopes, groundwater age-dating (radiocarbon), and geomorphic/geogenic spatial analyses was applied to a regional, highly developed coastal aquifer to explain the presence of nitrate at depth. The average δ(13) C value (-17.3 ± 2‰ VPDB, n = 27) is characteristic of groundwater originating from locally infiltrated precipitation through extensively cultivated soils. The average δ(18) O and δD values (-4.0 ± 0.1‰ VSMOW, n = 27; δD: -19.3 ± 1‰ VSMOW, n = 27, respectively) are similar to precipitation water derived from maritime sources feeding the region's surface water and groundwater. Stable and radioactive isotopes reveal significant mixing between shallow and deep aquifers due to high velocities, hydraulic connection, and input of local recharge water to depths. Groundwater overdevelopment enhances deeper and faster modern water downward flux, amplifying aquifer vulnerability. Therefore, aquifer vulnerability is a variable, dependent on the type and degree of stress conditions experienced by a groundwater system as well as the geospatial properties at the near surface.

  7. Geodatabase of the datasets used to represent the four aquifer subunits of the Cambrian-Ordovician aquifer system, Illinois, Iowa, Michigan, Minnesota, and Wisconsin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geodatabase includes spatial datasets that represent the Cambrian-Ordovician aquifer system in the States of Wisconsin, Michigan, Minnesota, Iowa, and Illinois....

  8. Environmental assessment of the potential effects of aquifer thermal energy storage systems on microorganisms in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, R.J.; Stewart, D.L.

    1988-03-01

    The primary objective of this study was to evaluate the potential environmental effects (both adverse and beneficials) of aquifer thermal energy storage (ATES) technology pertaining to microbial communities indigenous to subsurface environments (i.e., aquifers) and the propagation, movement, and potential release of pathogenic microorganisms (specifically, Legionella) within ATES systems. Seasonal storage of thermal energy in aquifers shows great promise to reduce peak demand; reduce electric utility load problems; contribute to establishing favorable economics for district heating and cooling systems; and reduce pollution from extraction, refining, and combustion of fossil fuels. However, concerns that the widespread implementation of this technology may have adverse effects on biological systems indigeneous to aquifers, as well as help to propagate and release pathogenic organisms that enter thee environments need to be resolved. 101 refs., 2 tabs.

  9. Deposition of large organic particles (macrodetritus in a sandy beach system (Puck Bay, Baltic Sea

    Directory of Open Access Journals (Sweden)

    Lech Kotwicki

    2005-06-01

    Full Text Available The aim of this study was to evaluate the amount of organic macrodetritus deposited on the sandy shores of the southern Baltic, and to determine the type of washout material and their chemical composition (carbon and nitrogen.     Over 900 samples of macrodetritus (particles retained on a 0.5 mm sieve were collected from seven sampling locations along a 120 km stretch of coastline in Poland at monthly intervals in 2002. Analysis of the C and N content of several categories of detritus supplied information about seasonal changes in and the ageing of algal debris, and indicated that the amount of carrion is constant; the latter is apparently always metabolised very rapidly. The annual deposition of macroalgal detritus on this coast was estimated at 15 000 tonnes fresh weight, that is around 75% of the primary production of filamentous macroalgae in Puck Bay.     In comparison with the amounts of kelp deposited on sandy beaches in South Africa (Griffiths & Stenton-Dozey 1981, the massive seaweed washouts on Mediterranean beaches (Morand & Briand 1996, or the deposition of algal mats in the northern Baltic (Norkko & Bonsdorff 1996a, the quantities of macrodetritus on the shore in the study area are average, even allowing for the fact that the Baltic Sea is highly eutrophic (HELCOM 2005.

  10. Quality of groundwater in the Denver Basin aquifer system, Colorado, 2003-5

    Science.gov (United States)

    Musgrove, MaryLynn; Beck, Jennifer A.; Paschke, Suzanne; Bauch, Nancy J.; Mashburn, Shana L.

    2014-01-01

    Groundwater resources from alluvial and bedrock aquifers of the Denver Basin are critical for municipal, domestic, and agricultural uses in Colorado along the eastern front of the Rocky Mountains. Rapid and widespread urban development, primarily along the western boundary of the Denver Basin, has approximately doubled the population since about 1970, and much of the population depends on groundwater for water supply. As part of the National Water-Quality Assessment Program, the U.S. Geological Survey conducted groundwater-quality studies during 2003–5 in the Denver Basin aquifer system to characterize water quality of shallow groundwater at the water table and of the bedrock aquifers, which are important drinking-water resources. For the Denver Basin, water-quality constituents of concern for human health or because they might otherwise limit use of water include total dissolved solids, fluoride, sulfate, nitrate, iron, manganese, selenium, radon, uranium, arsenic, pesticides, and volatile organic compounds. For the water-table studies, two monitoring-well networks were installed and sampled beneath agricultural (31 wells) and urban (29 wells) land uses at or just below the water table in either alluvial material or near-surface bedrock. For the bedrock-aquifer studies, domestic- and municipal-supply wells completed in the bedrock aquifers were sampled. The bedrock aquifers, stratigraphically from youngest (shallowest) to oldest (deepest), are the Dawson, Denver, Arapahoe, and Laramie-Fox Hills aquifers. The extensive dataset collected from wells completed in the bedrock aquifers (79 samples) provides the opportunity to evaluate factors and processes affecting water quality and to establish a baseline that can be used to characterize future changes in groundwater quality. Groundwater samples were analyzed for inorganic, organic, isotopic, and age-dating constituents and tracers. This report discusses spatial and statistical distributions of chemical constituents

  11. Hydrodynamical, hydrochemical and isotopic characterization of the Kourimat aquifer system (Essaouira basin, Morocco

    Directory of Open Access Journals (Sweden)

    Fernandes, P.

    2008-06-01

    Full Text Available The synclinal basin of Kourimat, subdivided in two sub-basins (Igounzar in the North, and Zeltene in the South, is situated in the oriental part of Essaouira basin shelters a carbonate aquifer system contained in the limestones and dolomitic limestones of the Cenomanian and the Turonian. These ground waters represent the only drinking water and irrigation resource for the region.The geological formations outcropping in the studied area, start with the clay and marly formations of the terminal Jurassic in the south of Zelten watershed, and end with the sandy and loamy Quaternary formations in coastal areas in the Low Qsob watershed. The Middle and Upper Cretaceous (marl, fractured limestone, and dolomites represent the rest of the stratigraphic series especially in the areas of the Igrounzar watershed (up to 85% of the outcrops and in Zelten (up to 50%.The field occupation is not very significant. It basically consists of three types: 1 cultures (essentially cereals where it is possible (on the marly soils of the Cretaceous, the Quaternary and the Eocene; 2 uncovered areas corresponding to the fissured and karstic limestone outcrops of the Cretaceous and the Jurassic formations, and 3 forests (coniferous trees in the downstream part of the catchments area (Plio-quaternary soils and mountainous reinforcements of the Western High Atlas. Like for other undeveloped areas of Morocco, the Meskala basin is also subjected to an intensive deforestation (wood for heating and cooking.The study undertaken on the Cenomano-turonian aquifer has allowed us to characterize it from the hydrodynamical, hydrogeological and hydrogeochemical point of view. The piezometric map of the two regrouped aquifer levels shows water flow senses from the SE to the NW. The hydraulic gradient varies from upstream to downstream, being weak n the central zone relative to the best hydrodynamic characteristics. The time evolution of the piezometry shows annual and seasonal

  12. Hydrogeologic framework and salinity distribution of the Floridan aquifer system of Broward County, Florida

    Science.gov (United States)

    Reese, Ronald S.; Cunningham, Kevin J.

    2014-01-01

    Concerns about water-level decline and seawater intrusion in the surficial Biscayne aquifer, currently the principal source of water supply to Broward County, prompted a study to refine the hydrogeologic framework of the underlying Floridan aquifer system to evaluate its potential as an alternative source of supply. This report presents cross sections that illustrate the stratigraphy and hydrogeology in eastern Broward County; maps of the upper surfaces and thicknesses of several geologic formations or units within the Floridan aquifer system; and maps of two of the potentially productive water-bearing zones within the system, the Upper Floridan aquifer and the Avon Park permeable zone. An analysis of data on rock depositional textures, associated pore networks, and flow zones in the Floridan aquifer system shows that groundwater moves through the system in two ways. These data support a conceptual, dual-porosity model of the system wherein groundwater moves either as concentrated flow in discrete, thin bedding-plane vugs or zones of vuggy megaporosity, or as diffuse flow through rocks with primarily interparticle and moldic-particle porosity. Because considerable exchange of groundwater may occur between the zones of vuggy and matrix-dominated porosity, understanding the distribution of that porosity and flow zone types is important to evaluating the suitability of the several units within the Floridan aquifer system for managing the water through practices such as aquifer storage and recovery (ASR). The salinity of the water in the Floridan aquifer system is highest in the central part of the study area, and lower toward the north and south. Although salinity generally increases with depth, in the western part of the study area a zone of relatively high saline water is perched above water of lower salinity in the underlying Avon Park permeable zone. Overall, the areas of highest salinity in the aquifer system coincide with those with the lowest estimated

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

    Science.gov (United States)

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

    2009-01-01

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

  14. Hydrogeology and water quality of the Floridan aquifer system and effects of Lower Floridan aquifer pumping on the Upper Floridan aquifer at Fort Stewart, Georgia

    Science.gov (United States)

    Clarke, John S.; Cherry, Gregory C.; Gonthier, Gerard J.

    2011-01-01

    Test drilling, field investigations, and digital modeling were completed at Fort Stewart, GA, during 2009?2010, to assess the geologic, hydraulic, and water-quality characteristics of the Floridan aquifer system and evaluate the effect of Lower Floridan aquifer (LFA) pumping on the Upper Floridan aquifer (UFA). This work was performed pursuant to the Georgia Environmental Protection Division interim permitting strategy for new wells completed in the LFA that requires simulation to (1) quantify pumping-induced aquifer leakage from the UFA to LFA, and (2) identify the equivalent rate of UFA pumping that would produce the same maximum drawdown in the UFA that anticipated pumping from LFA well would induce. Field investigation activities included (1) constructing a 1,300-foot (ft) test boring and well completed in the LFA (well 33P028), (2) constructing an observation well in the UFA (well 33P029), (3) collecting drill cuttings and borehole geophysical logs, (4) collecting core samples for analysis of vertical hydraulic conductivity and porosity, (5) conducting flowmeter and packer tests in the open borehole within the UFA and LFA, (6) collecting depth-integrated water samples to assess basic ionic chemistry of various water-bearing zones, and (7) conducting aquifer tests in new LFA and UFA wells to determine hydraulic properties and assess interaquifer leakage. Using data collected at the site and in nearby areas, model simulation was used to assess the effects of LFA pumping on the UFA. Borehole-geophysical and flowmeter data indicate the LFA at Fort Stewart consists of limestone and dolomitic limestone between depths of 912 and 1,250 ft. Flowmeter data indicate the presence of three permeable zones at depth intervals of 912-947, 1,090-1,139, and 1,211?1,250 ft. LFA well 33P028 received 50 percent of the pumped volume from the uppermost permeable zone, and about 18 and 32 percent of the pumped volume from the middle and lowest permeable zones, respectively. Chemical

  15. 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).

  16. Redox processes and water quality of selected principal aquifer systems

    Science.gov (United States)

    McMahon, P.B.; Chapelle, F.H.

    2008-01-01

    Reduction/oxidation (redox) conditions in 15 principal aquifer (PA) systems of the United States, and their impact on several water quality issues, were assessed from a large data base collected by the National Water-Quality Assessment Program of the USGS. The logic of these assessments was based on the observed ecological succession of electron acceptors such as dissolved oxygen, nitrate, and sulfate and threshold concentrations of these substrates needed to support active microbial metabolism. Similarly, the utilization of solid-phase electron acceptors such as Mn(IV) and Fe(III) is indicated by the production of dissolved manganese and iron. An internally consistent set of threshold concentration criteria was developed and applied to a large data set of 1692 water samples from the PAs to assess ambient redox conditions. The indicated redox conditions then were related to the occurrence of selected natural (arsenic) and anthropogenic (nitrate and volatile organic compounds) contaminants in ground water. For the natural and anthropogenic contaminants assessed in this study, considering redox conditions as defined by this framework of redox indicator species and threshold concentrations explained many water quality trends observed at a regional scale. An important finding of this study was that samples indicating mixed redox processes provide information on redox heterogeneity that is useful for assessing common water quality issues. Given the interpretive power of the redox framework and given that it is relatively inexpensive and easy to measure the chemical parameters included in the framework, those parameters should be included in routine water quality monitoring programs whenever possible.

  17. Three-dimensional conceptual model for the Hanford Site unconfined aquifer system: FY 1994 status report

    Energy Technology Data Exchange (ETDEWEB)

    Thorne, P.D.; Chamness, M.A.; Vermeul, V.R.; Macdonald, Q.C.; Schubert, S.E.

    1994-11-01

    This report documents work conducted during the fiscal year 1994 to development an improved three-dimensional conceptual model of ground-water flow in the unconfined aquifer system across the Hanford Site Ground-Water Surveillance Project, which is managed by Pacific Northwest Laboratory. The main objective of the ongoing effort to develop an improved conceptual model of ground-water flow is to provide the basis for improved numerical report models that will be capable of accurately predicting the movement of radioactive and chemical contaminant plumes in the aquifer beneath Hanford. More accurate ground-water flow models will also be useful in assessing the impacts of changes in facilities and operations. For example, decreasing volumes of operational waste-water discharge are resulting in a declining water table in parts of the unconfined aquifer. In addition to supporting numerical modeling, the conceptual model also provides a qualitative understanding of the movement of ground water and contaminants in the aquifer.

  18. Conceptual and numerical modeling of the Guaraní Aquifer System

    Directory of Open Access Journals (Sweden)

    L. Rodríguez

    2012-08-01

    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. 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 on early years to a losing condition over time. Water is discharged through the aquifer boundaries, except at the eastern boundary. On average, pumping represented 16.2% of inflows while aquifer storage experienced a small overall increment. The model water balance indicates that the current rate of

  19. [Effects of long-term fertilization on pH buffer system of sandy loam calcareous fluvor-aquic soil].

    Science.gov (United States)

    Wang, Ji-Dong; Qi, Bing-Jie; Zhang, Yong-Chun; Zhang, Ai-Jun; Ning, Yun-Wang; Xu, Xian-Ju; Zhang, Hui; Ma, Hong-Bo

    2012-04-01

    Soil samples (0-80 cm) were collected from a 30-year fertilization experimental site in Xuzhou, Jiangsu Province of East China to study the variations of the pH, calcium carbonate and active calcium carbonate contents, and pH buffer capacity of sandy loam calcareous fluvor-aquic soil under different fertilization treatments. Thirty-year continuous application of different fertilizers accelerated the acidification of topsoil (0-20 cm), with the soil pH decreased by 0.41-0.70. Under different fertilization, the soil pH buffer capacity (pHBC) varied from 15.82 to 21.96 cmol x kg(-1). As compared with no fertilization, single N fertilization decreased the pHBC significantly, but N fertilization combined with organic fertilization could significantly increase the pHBC. The soil pHBC had significant positive correlations with soil calcium carbonate and active calcium carbonate contents, but less correlation with soil organic matter content and soil cation exchange capacity, suggesting that after a long-term fertilization, the sandy loam calcareous fluvor-aquic soil was still of an elementary calcium carbonate buffer system, and soil organic matter and cation exchange capacity contributed little to the buffer system. The soil calcium carbonate and active calcium carbonate contents were greater in 0-40 cm than in 40-80 cm soil layer. Comparing with soil calcium carbonate, soil active calcium carbonate was more sensitive to reflect the changes of soil physical and chemical properties, suggesting that the calcium carbonate buffer system could be further classified as soil active calcium carbonate buffer system.

  20. Benthic macrofauna of sandy intertidal zone at Santos estuarine system, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    T.N. Corbisier

    1991-01-01

    Full Text Available Species composition, faunal density, species diversity and zonation patterns of benthic macrofauna, as well as its relation to sediment characteristics were examined and compared in three sandy beaches on the polyhaline area at Santos estuarine system in the State of São Paulo. Samples were collected quarterly during one year (July/1977 - May/1978. Low, mean and high intertidal levels were sampled. Polyehaetes dominated the fauna, both in terms of numbers of species and numbers of individuals. The community structure of Ponta da Praia beach was characterized by high density, low diversity (H' and evenness (J', due to the dominance of the spionid Scolelepis squamata. At Vicente de Carvalho the fauna was characterized by the dominance of the polyehaetes Laeonereis acuta and Capitella capitata and presented low density, high diversity and evenness. At Bertioga Channel, intermediate values were observed and the fauna was dominated by Scololepis squamata andLaeonereis acuta. The sediment texture was responsible for those figures, although some differences in diversity may be explained by differences in wave energy. The low number of crustaceans and molluscs suggests the effect of the estuarine pollution upon the fauna. The zonation pattern of both species distribution and community structure differed at the studied sites; it was not correlated with sediment characteristics which were relatively uniform down shore; however, the lowest diversity was observed at the high level in all sites.Neste trabalho foi estudada a macrofauna bentônica da zona entremarés arenosa da área polihalina do sistema estuarino de Santos. A composição em espécies, densidade e diversidade e o padrão de zonação da fauna foram analisados e comparados, bem como sua relação com as características do sedimento em três praias arenosas. As amostras foram coletadas trimestralmente durante o período de um ano (julho/1977 - maio/1978. Em cada local, foram amostrados os n

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

    Science.gov (United States)

    Ryder, Paul D.

    1988-01-01

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

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

    Science.gov (United States)

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

    1997-01-01

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

  3. Hydrogeology and water quality of the Floridan aquifer system and effect of Lower Floridan aquifer pumping on the Upper Floridan aquifer at Hunter Army Airfield, Chatham County, Georgia

    Science.gov (United States)

    Clarke, John S.; Williams, Lester J.; Cherry, Gregory C.

    2010-01-01

    Test drilling and field investigations, conducted at Hunter Army Airfield (HAAF), Chatham County, Georgia, during 2009, were used to determine the geologic, hydraulic, and water-quality characteristics of the Floridan aquifer system and to evaluate the effect of Lower Floridan aquifer (LFA) pumping on the Upper Floridan aquifer (UFA). Field investigation activities included (1) constructing a 1,168-foot (ft) test boring and well completed in the LFA, (2) collecting drill cuttings and borehole geophysical logs, (3) collecting core samples for analysis of vertical hydraulic conductivity and porosity, (4) conducting flowmeter and packer tests in the open borehole within the UFA and LFA, (5) collecting depth-integrated water samples to assess basic ionic chemistry of various water-bearing zones, and (6) conducting aquifer tests in the new LFA well and in an existing UFA well to determine hydraulic properties and assess interaquifer leakage. Using data collected at the site and in nearby areas, model simulation was used to quantify the effects of interaquifer leakage on the UFA and to determine the amount of pumping reduction required in the UFA to offset drawdown resulting from the leakage. Borehole-geophysical and flowmeter data indicate the LFA at HAAF consists of limestone and dolomitic limestone between depths of 703 and 1,080 ft, producing water from six major permeable zones: 723-731; 768-785; 818-837; 917-923; 1,027-1,052; and 1,060-1,080 ft. Data from a flowmeter survey, conducted at a pumping rate of 748 gallons per minute (gal/min), suggest that the two uppermost zones contributed 469 gal/min or 62.6 percent of the total flow during the test. The remaining four zones contributed from 1.7 to 18 percent of the total flow. Grab water samples indicate that with the exception of fluoride, constituent concentrations in the LFA increased with depth; water from the deepest interval (1,075 ft) contained chloride and sulfate concentrations of 480 and 240 milligrams per

  4. Hysteresis, regime shifts, and non-stationarity in aquifer recharge-storage-discharge systems

    Science.gov (United States)

    Klammler, Harald; Jawitz, James; Annable, Michael; Hatfield, Kirk; Rao, Suresh

    2016-04-01

    Based on physical principles and geological information we develop a parsimonious aquifer model for Silver Springs, one of the largest karst springs in Florida. The model structure is linear and time-invariant with recharge, aquifer head (storage) and spring discharge as dynamic variables at the springshed (landscape) scale. Aquifer recharge is the hydrological driver with trends over a range of time scales from seasonal to multi-decadal. The freshwater-saltwater interaction is considered as a dynamic storage mechanism. Model results and observed time series show that aquifer storage causes significant rate-dependent hysteretic behavior between aquifer recharge and discharge. This leads to variable discharge per unit recharge over time scales up to decades, which may be interpreted as a gradual and cyclic regime shift in the aquifer drainage behavior. Based on field observations, we further amend the aquifer model by assuming vegetation growth in the spring run to be inversely proportional to stream velocity and to hinder stream flow. This simple modification introduces non-linearity into the dynamic system, for which we investigate the occurrence of rate-independent hysteresis and of different possible steady states with respective regime shifts between them. Results may contribute towards explaining observed non-stationary behavior potentially due to hydrological regime shifts (e.g., triggered by gradual, long-term changes in recharge or single extreme events) or long-term hysteresis (e.g., caused by aquifer storage). This improved understanding of the springshed hydrologic response dynamics is fundamental for managing the ecological, economic and social aspects at the landscape scale.

  5. Hurricane Sandy and earthquakes

    OpenAIRE

    MAVASHEV BORIS; MAVASHEV IGOR

    2013-01-01

    Submit for consideration the connection between formation of a hurricane Sandy and earthquakes. As a rule, weather anomalies precede and accompany earthquakes. The hurricane Sandy emerged 2 days prior to strong earthquakes that occurred in the area. And the trajectory of the hurricane Sandy matched the epicenter of the earthquakes. Possibility of early prediction of natural disasters will minimize the moral and material damage.

  6. Simulation of Groundwater Flow in the Coastal Plain Aquifer System of Virginia

    Science.gov (United States)

    Heywood, Charles E.; Pope, Jason P.

    2009-01-01

    The groundwater model documented in this report simulates the transient evolution of water levels in the aquifers and confining units of the Virginia Coastal Plain and adjacent portions of Maryland and North Carolina since 1890. Groundwater withdrawals have lowered water levels in Virginia Coastal Plain aquifers and have resulted in drawdown in the Potomac aquifer exceeding 200 feet in some areas. The discovery of the Chesapeake Bay impact crater and a revised conceptualization of the Potomac aquifer are two major changes to the hydrogeologic framework that have been incorporated into the groundwater model. The spatial scale of the model was selected on the basis of the primary function of the model of assessing the regional water-level responses of the confined aquifers beneath the Coastal Plain. The local horizontal groundwater flow through the surficial aquifer is not intended to be accurately simulated. Representation of recharge, evapotranspiration, and interaction with surface-water features, such as major rivers, lakes, the Chesapeake Bay, and the Atlantic Ocean, enable simulation of shallow flow-system details that influence locations of recharge to and discharge from the deeper confined flow system. The increased density of groundwater associated with the transition from fresh to salty groundwater near the Atlantic Ocean affects regional groundwater flow and was simulated with the Variable Density Flow Process of SEAWAT (a U.S. Geological Survey program for simulation of three-dimensional variable-density groundwater flow and transport). The groundwater density distribution was generated by a separate 108,000-year simulation of Pleistocene freshwater flushing around the Chesapeake Bay impact crater during transient sea-level changes. Specified-flux boundaries simulate increasing groundwater underflow out of the model domain into Maryland and minor underflow from the Piedmont Province into the model domain. Reported withdrawals accounted for approximately

  7. The Southern Hills regional aquifer system of southeastern Louisiana and southwestern Mississippi

    Science.gov (United States)

    Buono, A.

    1983-01-01

    The Southern Hills regional aquifer system, named in a petition to the Environmental Protection Agency for designation as a sole or principal source of drinking water, is the primary source of public and domestic supplies in the northern 10 parishes of southeastern Louisiana. The gulfward dipping and thickening, complexly interbedded aquifer system extends from the northern limit of the recharge area near Vicksburg, Mississippi, as far as the Baton Rouge area in southeastern Louisiana. As many as 13 interdependent aquifer units compose the system in the southern part of the area and are known to coalesce or pinch out northward (updip) into fewer units. Aquifer water is almost exclusively a soft, sodium bicarbonate type with an average dissolved-solids concentration of about 220 milligrams per liter in southeastern Louisiana. Although several streams are available as alternatives for supply, they have not been accepted by local officials because of the additional water treatment that would be necessary and the extensive distribution system needed to deliver water to areas not near a source stream. Groundwater use in 1980 for public and domestic supply averaged 121 Mgal/d (million gallons per day), serving 744,000 people in southeastern Louisiana. In southwestern Mississippi, where the aquifer system is also the primary source for public and domestic supply, water use for these categories in 1980 totaled 25 Mgal/d, serving about 273,000 people. (USGS)

  8. The Maryland Coastal Plain Aquifer Information System: A GIS-based tool for assessing groundwater resources

    Science.gov (United States)

    Andreasen, David C.; Nardi, Mark R.; Staley, Andrew W.; Achmad, Grufron; Grace, John W.

    2016-01-01

    Groundwater is the source of drinking water for ∼1.4 million people in the Coastal Plain Province of Maryland (USA). In addition, groundwater is essential for commercial, industrial, and agricultural uses. Approximately 0.757 × 109 L d–1 (200 million gallons/d) were withdrawn in 2010. As a result of decades of withdrawals from the coastal plain confined aquifers, groundwater levels have declined by as much as 70 m (230 ft) from estimated prepumping levels. Other issues posing challenges to long-term groundwater sustainability include degraded water quality from both man-made and natural sources, reduced stream base flow, land subsidence, and changing recharge patterns (drought) caused by climate change. In Maryland, groundwater supply is managed primarily by the Maryland Department of the Environment, which seeks to balance reasonable use of the resource with long-term sustainability. The chief goal of groundwater management in Maryland is to ensure safe and adequate supplies for all current and future users through the implementation of appropriate usage, planning, and conservation policies. To assist in that effort, the geographic information system (GIS)–based Maryland Coastal Plain Aquifer Information System was developed as a tool to help water managers access and visualize groundwater data for use in the evaluation of groundwater allocation and use permits. The system, contained within an ESRI ArcMap desktop environment, includes both interpreted and basic data for 16 aquifers and 14 confining units. Data map layers include aquifer and ­confining unit layer surfaces, aquifer extents, borehole information, hydraulic properties, time-series groundwater-level data, well records, and geophysical and lithologic logs. The aquifer and confining unit layer surfaces were generated specifically for the GIS system. The system also contains select groundwater-quality data and map layers that quantify groundwater and surface-water withdrawals. The aquifer

  9. Characterisation of phosphate solubilising bacteria in sandy loam soil under chickpea cropping system.

    Science.gov (United States)

    Singh, Machiavelli; Tejo Prakash, N

    2012-06-01

    With the aim to explore the possible role of phosphate-solubilizing bacteria (PSB) in phosphorus (P) cycling in agricultural soils, we isolated PSB inhabiting naturally in the sandy loam soils under chickpea cropping of Patiala (Punjab State). A total of 31 bacterial isolates showing solubilizing activities were isolated on Pikovskaya agar plates. The potent phosphate solubilizers were selected for further characterization. These isolates were shown to belong to the genera Pseudomonas and Serratia by partial sequencing analysis of their respective 16S rDNA genes. ERIC-PCR based fingerprinting was done for tracking the survival of introduced populations of the PSB during mass inoculation of these strains under chickpea plots. The results showed positive correlation (r(2) = 0.853) among soil phosphatase activity and phosphate solubilizers population, which was also positively correlated (r(2) = 0.730) to available phosphorus. Identification and characterization of soil PSB for the effective plant growth-promotion broadens the spectrum of phosphate solubilizers available for field application.

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

    Science.gov (United States)

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

  11. Water security and services in the ocean-aquifer system

    Science.gov (United States)

    Taniguchi, M.

    2011-12-01

    Coastal vulnerability and water security are both important research subjects on global environmental problems under the pressures of changing climate and societies. A six years research project by RIHN on the coastal subsurface environments in seven Asia cities revealed that subsurface environmental problems including saltwater intrusion, groundwater contamination and subsurface thermal anomalies occurred one after another depending on the development stage of the cities during the last 100 years. Exchanges of water between ocean and aquifer in the coastal cities depend on driving force from land of natural resources capacities such as groundwater recharge rate, and social changes such as excessive groundwater pumping due to industrialization. Risk assessments and managements for aquifers which are parts of water security have been made for seven Asian coastal cities. On the other hand, submarine groundwater discharge (SGD) into the ocean provides water services directly to the coastal ecosystem through nutrient transports from land to the ocean. Constant geophysical and geochemical conditions served by SGD provide sustainable services to the coastal environment. Flora and fauna which prefer brackish water in the coastal zone depend on not only river water discharge but also SGD. Ocean -aquifer interaction can be found in the coastal ecosystem including sea shell, sea grass and fishes in the coastal zone though SGD. In order to evaluate a coastal security and sustainable environment, not only risk assessments due to disasters but also water services are important, and the both are evaluated in Asian coastal zones.

  12. Capture zone of a multi-well system in bounded peninsula-shaped aquifers.

    Science.gov (United States)

    Zarei-Doudeji, Somayeh; Samani, Nozar

    2014-08-01

    In this paper we present the equation of capture zone for multi-well system in peninsula-shaped confined and unconfined aquifers. The aquifer is rectangular in plan view, bounded along three sides, and extends to infinity at the fourth side. The bounding boundaries are either no-flow (impervious) or in-flow (constant head) so that aquifers with six possible boundary configurations are formed. The well system is consisted of any number of extraction or injection wells or combination of both with any flow rates. The complex velocity potential equations for such a well-aquifer system are derived to delineate the capture envelop. Solutions are provided for the aquifers with and without a uniform regional flow of any directions. The presented equations are of general character and have no limitations in terms of well numbers, positions and types, extraction/injection rate, and regional flow rate and direction. These solutions are presented in form of capture type curves which are useful tools in hands of practitioners to design in-situ groundwater remediation systems, to contain contaminant plumes, to evaluate the surface-subsurface water interaction and to verify numerical models.

  13. Conceptual model of the Great Basin carbonate and alluvial aquifer system

    Science.gov (United States)

    Heilweil, Victor M.; Brooks, Lynette E.

    2011-01-01

    A conceptual model of the Great Basin carbonate and alluvial aquifer system (GBCAAS) was developed by the U.S. Geological Survey (USGS) for a regional assessment of groundwater availability as part of a national water census. The study area is an expansion of a previous USGS Regional Aquifer Systems Analysis (RASA) study conducted during the 1980s and 1990s of the carbonate-rock province of the Great Basin. The geographic extent of the study area is 110,000 mi2, predominantly in eastern Nevada and western Utah, and includes 165 hydrographic areas (HAs) and 17 regional groundwater flow systems.

  14. Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

    Science.gov (United States)

    Wong, F. L.; Woodrow, D. L.; McGann, M. L.

    2012-12-01

    Heavy minerals have been used to trace the sources and transportation of sandy sediment in San Francisco Bay and nearby coastal areas since the 1960s. We have the opportunity to sample similar environments and revisit the heavy mineral populations under the current San Francisco Coastal System study of the provenance of beach sand. Most of the sandy sediment in San Francisco Bay can be traced to distant sources including the Sierra Nevada batholith and associated terranes with local contributions from the Franciscan Complex. Heavy minerals from Sierran sources include ordinary hornblende, metamorphic amphiboles, and hypersthene while those from the Franciscan Complex include other types of pyroxene, epidote, basaltic hornblende, and glaucophane... Tertiary strata and volcanics in the surrounding hills and displaced Sierran rocks found on the continental shelf west of the San Andreas Fault Zone introduce similar minerals, but perhaps in a lesser volume to be identified as major contributors... The primary result of cluster analysis of heavy minerals separated from sand-sized sediment taken within San Francisco Bay, the adjacent continental shelf, local beaches, cliffs outside the Golden Gate, and upstream drainages indicate a widespread occurrence of sediment traceable to the Sierra Nevada. A second cluster of samples identifies samples of mixed Sierran and Franciscan lineage within the strait of the Golden Gate, on the San Francisco bar, and on coastal beaches. Sediment samples with predominantly Franciscan mineral content appear on beaches around Point Reyes, possibly transported from the Russian River. The heavy mineral composition supports transport from the east, through San Francisco Bay and out the Golden Gate to the San Francisco bar and southward.

  15. Temperature Distribution and Thermal Performance of an Aquifer Thermal Energy Storage System

    Science.gov (United States)

    Ganguly, Sayantan

    2017-04-01

    Energy conservation and storage has become very crucial to make use of excess energy during times of future demand. Excess thermal energy can be captured and stored in aquifers and this technique is termed as Aquifer Thermal Energy Storage (ATES). Storing seasonal thermal energy in water by injecting it into subsurface and extracting in time of demand is the principle of an ATES system. Using ATES systems leads to energy savings, reduces the dependency on fossil fuels and thus leads to reduction in greenhouse gas emission. This study numerically models an ATES system to store seasonal thermal energy and evaluates the performance of it. A 3D thermo-hydrogeological numerical model for a confined ATES system is presented in this study. The model includes heat transport processes of advection, conduction and heat loss to confining rock media. The model also takes into account regional groundwater flow in the aquifer, geothermal gradient and anisotropy in the aquifer. Results show that thermal injection into the aquifer results in the generation of a thermal-front which grows in size with time. Premature thermal-breakthrough causes thermal interference in the system when the thermal-front reaches the production well and consequences in the fall of system performance and hence should be avoided. This study models the transient temperature distribution in the aquifer for different flow and geological conditions. This may be effectively used in designing an efficient ATES project by ensuring safety from thermal-breakthrough while catering to the energy demand. Based on the model results a safe well spacing is proposed. The thermal energy discharged by the system is determined and strategy to avoid the premature thermal-breakthrough in critical cases is discussed. The present numerical model is applied to simulate an experimental field study which is found to approximate the field results quite well.

  16. Detailed performance and environmental monitoring of aquifer heating and cooling systems

    Science.gov (United States)

    Acuna, José; Ahlkrona, Malva; Zandin, Hanna; Singh, Ashutosh

    2016-04-01

    The project intends to quantify the performance and environmental impact of large scale aquifer thermal energy storage, as well as point at recommendations for operating and estimating the environmental footprint of future systems. Field measurements, test of innovative equipment as well as advanced modelling work and analysis will be performed. The following aspects are introduced and covered in the presentation: -Thermal, chemical and microbiological influence of akvifer thermal energy storage systems: measurement and evaluation of real conditions and the influence of one system in operation. -Follow up of energy extraction from aquifer as compared to projected values, recommendations for improvements. -Evaluation of the most used thermal modeling tool for design and calculation of groundwater temperatures, calculations with MODFLOW/MT3DMS -Test and evaluation of optical fiber cables as a way to measure temperatures in aquifer thermal energy storages

  17. Geologic history and hydrogeologic setting of the Edwards-Trinity aquifer system, west-central Texas

    Science.gov (United States)

    Barker, R.A.; Bush, P.W.; Baker, E.T.

    1994-01-01

    The Edwards-Trinity aquifer system underlies about 42,000 square miles of west-central Texas. Nearly flat-lying, mostly Comanche (Lower Cretaceous) strata of the aquifer system thin northwestward atop massive pre-Cretaceous rocks that are comparatively impermeable and structurally complex. From predominately terrigenous clastic sediments in the east and fluvialdeltaic (terrestrial) deposits in the west, the rocks of early Trinitian age grade upward into supratidal evaporitic and dolomitic strata, intertidal limestone and dolostone, and shallow-marine, openshelf, and reefal strata of late Trinitian, Fredericksburgian, and Washitan age. A thick, downfaulted remnant of mostly open-marine strata of Eaglefordian through Navarroan age composes a small, southeastern part of the aquifer system.

  18. Hydrogeology of the Helena Valley-fill aquifer system, west-central Montana. Water resources investigation

    Energy Technology Data Exchange (ETDEWEB)

    Briar, D.W.; Madison, J.P.

    1992-01-01

    The report, which presents the study results, describes the hydrogeology of the valley-fill aquifer system. Specific objectives were to: describe the geometry and the hydraulic characteristics of the aquifer system; define the potentiometric surface and the direction of ground-water flow; locate and quantify sources of ground-water recharge and discharge including surface- and ground-water interactions; and characterize the water quality in terms of susceptibility of the aquifer system to contamination and in terms of concentrations, distribution, and sources of major ions, trace elements, and organic compounds. The results of the study will be useful to the development of a comprehensive management program for the use and protection of the ground-water resources of the Helena Valley.

  19. Field testing of a high-temperature aquifer thermal energy storage system

    Energy Technology Data Exchange (ETDEWEB)

    Sterling, R.L.; Hoyer, M.C. [Univ. of Minnesota, Minneapolis, MN (United States)

    1989-03-01

    The University of Minnesota Aquifer Thermal Energy Storage (ATES) System has been operated as a field test facility for the past six years. Four short-term and two long-term cycles have been completed to data providing a greatly increased understanding of the efficiency and geochemical effects of high-temperature aquifer thermal energy storage. A third long-term cycle is currently being planned to operate the ATES system in conjunction with a real heating load and to further study the geochemical impact on the aquifer from heated waste storage cycles. The most critical activities in the preparation for the next cycle have proved to be the applications for the various permits and variances necessary to conduct the third cycle and the matching of the characteristics of the ATES system during heat recovery with a suitable adjacent building thermal load.

  20. Geochemical impacts of groundwater heat pump systems in an urban alluvial aquifer with evaporitic bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Garrido Schneider, Eduardo A. [Geological Survey of Spain (IGME), C/ Manuel Lasala no. 44, 9B, 50006 Zaragoza (Spain); García-Gil, Alejandro, E-mail: agargil@unizar.es [Department of Earth Sciences, University of Zaragoza, C/ Pedro Cerbuna 12, 50009 Zaragoza (Spain); GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18–26, 08034 Barcelona (Spain); Vázquez-Suñè, Enric [GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18–26, 08034 Barcelona (Spain); Sánchez-Navarro, José Á. [Department of Earth Sciences, University of Zaragoza, C/ Pedro Cerbuna 12, 50009 Zaragoza (Spain)

    2016-02-15

    In the last decade, there has been an extensive use of shallow geothermal exploitations in urban environments. Although the thermal interference between exploitations has been recently studied, there is a lack of knowledge regarding the geochemical impacts of those systems on the aquifers where they are installed. Groundwater flow line scale and well-doublet scale research work has been conducted at city scale to quantify the geochemical interaction of shallow geothermal exploitations with the environment. A comprehensive analysis was conducted on data obtained from a monitoring network specifically designed to control and develop aquifer policies related to thermal management of the aquifer. The geochemical impacts were evaluated from a thermodynamic point of view by means of saturation index (SI) calculations with respect to the different mineral species considered in the system. The results obtained indicate limited geochemical interaction with the urban environment in most of the situations. However, there are some cases where the interaction of the groundwater heat pump installations with the evaporitic bedrock resulted in the total disablement of the exploitation system operation wells. The application of the tool proposed proved to be pragmatic in the evaluation of geochemical impacts. Injection of water into the aquifer can trigger an important bedrock gypsum and halite dissolution process that is partly responsible for scaling in well casing pipes and collapse of the terrain in the vicinity of injection wells. - Highlights: • We studied geochemical impacts of groundwater heat pump systems. • We have sampled a monitoring network in an energetically exploited urban aquifer. • A limited geochemical interaction has been found in most of the exploitations. • Reinjection into the aquifer produces an important bedrock gypsum dissolution. • Scaling in well casing pipes and collapse of the terrain have been observed.

  1. Applicable conditions for a classification system of aquifer-protective mining in hallow coal seams

    Institute of Scientific and Technical Information of China (English)

    Liu Yude; Zhang Dongsheng; Fan Gangwei; Yan Shoufeng

    2011-01-01

    Based on the conclusions of domestic and foreign research,we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine.We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method.From our calculations and analyses of variance,we used factors such as the overlying strata strength,mining disturbing factors and rock integrity as related factors of the composite index.We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock.the thickness of the weathered zone and the size of safety coal-rock pillars.As a result,we propose the preliminary classification system of aquifer-protective mining in shallow coal seams.It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions.

  2. Geophysical log database for the Floridan aquifer system and southeastern Coastal Plain aquifer system in Florida and parts of Georgia, Alabama, and South Carolina

    Science.gov (United States)

    Williams, Lester J.; Raines, Jessica E.; Lanning, Amanda E.

    2013-01-01

    The U.S. Geological Survey (USGS) Groundwater Resources Program began two regional studies in the southeastern United States in the fall of 2009 to investigate ground-water availability of fresh and brackish water resources: (1) groundwater availability of the Floridan aquifer system, (http://water.usgs.gov/ogw/gwrp/activities/regional.html), and (2) saline water aquifer mapping in the southeastern United States. A common goal for both studies was to gather available geophysical logs and related data from the State geological surveys and the USGS that would be used as a basis for developing a hydrogeologic framework for the study area. Similar efforts were undertaken by the USGS Floridan and Southeastern Coastal Plain Regional Aquifer-System Analysis (RASA) Program from the 1970s to mid-1990s (Miller, 1986; Renken, 1996). The logs compiled for these older efforts were difficult to access from the paper files; however, and partly because of this, older and newer logs were compiled into a single digital database for the current study. The purpose of this report is to summarize the different types of logs and related data contained in the database and to provide these logs in a digital format that can be accessed online through the database and files accompanying this report (http://pubs.usgs.gov/ds/760/).

  3. Assessing the Vulnerability of Public-Supply Wells to Contamination: Floridan Aquifer System Near Tampa, Florida

    Science.gov (United States)

    Jagucki, Martha L.; Katz, Brian G.; Crandall, Christy A.; Eberts, Sandra M.

    2009-01-01

    This fact sheet highlights findings from the vulnerability study of a public-supply well in Temple Terrace, Florida, northeast of Tampa. The well selected for study typically produces water at the rate of 700 gallons per minute from the Upper Floridan aquifer. Water samples were collected at the public-supply well and at monitoring wells installed in or near the simulated zone of contribution to the supply well. Samples of untreated water from the public-supply wellhead contained the undesirable constituents nitrate, arsenic, uranium, radon-222, volatile organic compounds (VOCs), and pesticides, although all were detected at concentrations less than established drinking-water standards, where such standards exist. Overall, study findings point to four primary factors that affect the movement and fate of contaminants and the vulnerability of the public-supply well in Temple Terrace: (1) groundwater age (how long ago water entered, or recharged, the aquifer); (2) short-circuiting of contaminated water through sinkholes; (3) natural geochemical processes within the aquifer; and (4) pumping stress. Although the public-supply well is completed in the Upper Floridan aquifer, it produces water with concentrations of nitrate, VOCs, and the natural contaminant radon that are intermediate between the typical composition of water from the Upper Floridan aquifer and that of the overlying surficial aquifer system. Mixing calculations show that the water produced by the public-supply well could consist of upwards of 50 percent water from the surficial aquifer system mixed with water from the Upper Floridan aquifer. Anthropogenically affected water from the surficial aquifer system travels rapidly to depth through sinkholes that must be directly connected to the cavernous zone intersected by the public-supply well (and several other production wells in the region). Such solution features serve as fast pathways to the well and circumvent the natural attenuation of nitrate and

  4. Water withdrawals and trends from the Floridan aquifer system in the southeastern United States, 1950-2000

    Science.gov (United States)

    Marella, Richard L.; Berndt, Marian P.

    2005-01-01

    The Floridan aquifer system in the southeastern United States is one of the most productive aquifers in the world (Miller, 1990). This aquifer system underlies an area of about 100,000 square miles in southern Alabama, eastern and southern Georgia, southeastern Mississippi, southern South Carolina, and all of Florida. The Floridan aquifer system is the primary source of water for nearly 10 million people and supports agriculture, industry, and tourism throughout most of the region. In most areas, water from this aquifer is potable and needs very little treatment before use. However, in southern Florida (south of Lake Okeechobee), northwestern Florida and southern Alabama and Mississippi (Pensacola and westward), and eastern South Carolina, water in the aquifer system generally is not potable. The purpose of this report is to: Provide a general description of the Floridan aquifer system; Discuss water withdrawals by category for 2000; Highlight trends in water withdrawals between 1950 and 2000; and Provide a brief summary on the effects that human impacts have on the Floridan aquifer system.

  5. Groundwater quality in the Northern Atlantic Coastal Plain aquifer system, eastern United States

    Science.gov (United States)

    Lindsey, Bruce; Belitz, Kenneth

    2017-01-19

    Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water. The Northern Atlantic Coastal Plain aquifer system constitutes one of the important areas being evaluated. One or more inorganic constituents with human-health benchmarks were detected at high concentrations in about 15 percent of the study area and at moderate concentrations in about 17 percent. Organic constituents were not detected at high concentrations in the study area.

  6. Elevated naturally occurring arsenic in a semiarid oxidizing system, Southern High Plains aquifer, Texas, USA

    Science.gov (United States)

    Scanlon, B.R.; Nicot, J.-P.; Reedy, R.C.; Kurtzman, D.; Mukherjee, A.; Nordstrom, D.K.

    2009-01-01

    High groundwater As concentrations in oxidizing systems are generally associated with As adsorption onto hydrous metal (Al, Fe or Mn) oxides and mobilization with increased pH. The objective of this study was to evaluate the distribution, sources and mobilization mechanisms of As in the Southern High Plains (SHP) aquifer, Texas, relative to those in other semiarid, oxidizing systems. Elevated groundwater As levels are widespread in the southern part of the SHP (SHP-S) aquifer, with 47% of wells exceeding the current EPA maximum contaminant level (MCL) of 10 μg/L (range 0.3–164 μg/L), whereas As levels are much lower in the north (SHP-N: 9% ⩾ As MCL of 10 μg/L; range 0.2–43 μg/L). The sharp contrast in As levels between the north and south coincides with a change in total dissolved solids (TDS) from 395 mg/L (median north) to 885 mg/L (median south). Arsenic is present as arsenate (As V) in this oxidizing system and is correlated with groundwater TDS (Spearman’s ρ = 0.57). The most likely current source of As is sorbed As onto hydrous metal oxides based on correlations between As and other oxyanion-forming elements (V, ρ = 0.88; Se, ρ = 0.54; B, ρ = 0.51 and Mo, ρ = 0.46). This source is similar to that in other oxidizing systems and constitutes a secondary source; the most likely primary source being volcanic ashes in the SHP aquifer or original source rocks in the Rockies, based on co-occurrence of As and F (ρ = 0.56), oxyanion-forming elements and SiO2 (ρ = 0.41), which are found in volcanic ashes. High groundwater As concentrations in some semiarid oxidizing systems are related to high evaporation. Although correlation of As with TDS in the SHP aquifer may suggest evaporative concentration, unenriched stable isotopes (δ2H: −65 to −27; δ18O: −9.1 to −4.2) in the SHP aquifer do not support evaporation. High TDS in the SHP aquifer is most likely related to upward movement of saline water from the underlying

  7. Long-term geochemical evaluation of the coastal Chicot aquifer system, Louisiana, USA

    Science.gov (United States)

    Borrok, David M.; Broussard, Whitney P.

    2016-02-01

    Groundwater is increasingly being overdrafted in the Gulf and Atlantic Coastal regions of the United States. Geochemical data associated with groundwater in these aquifers can provide important information on changes in salinity, recharge, and reaction pathways that can be used to improve water management strategies. Here we evaluated long-term geochemical changes associated with the 23,000 km2 Chicot aquifer system in Louisiana, USA. The Chicot aquifer is currently being overdrafted by about 1,320,000 m3 per day. We compiled selected bulk geochemical data from samples collected from 20 wells in the Chicot aquifer from 1993 to 2015. Oxygen and hydrogen isotope measurements were additionally completed for the 2014 samples. We identified three zones of groundwater with distinctive geochemical character; (1) A groundwater recharge zone in the northern part of the study area with low pH, low salinity, and low temperature relative to other groundwater samples, (2) a groundwater recharge zone in the southeastern part of the study area with low temperature, high alkalinity, and higher Ca and Mg concentrations compared to the other groundwater samples, and (3) groundwater in the southwestern part of the aquifer system with high salinity, high temperature, and a ∼1:1 Na/Cl ratio. The geochemistry of these regions has been relatively stable over the last ∼20 years. However, in the drought year of 2011, the estimated extent of zones with elevated salinity increased substantially. Geochemical evidence suggests that there was increased infiltration of deeper, more salt-rich waters into the shallower Chicot aquifer.

  8. Historical saturated thickness of the Edwards-Trinity aquifer system and selected contiguous hydraulically connected units, west-central Texas

    Science.gov (United States)

    Ardis, Ann F.; Barker, Rene A.

    1993-01-01

    The Edwards-Trinity Regional Aquifer-System Analysis (RASA) is one of 25 completed or ongoing studies conducted by the U.S. Geological Survey on regional aquifer systems that individually provide essential quantities of ground water to large parts of the country. Underlying about 42,000 mi2 of west-central Texas, the Edwards-Trinity aquifer system extends approximately from Atascosa County in the southeast to Culberson County in the northwest and from the Rio Grande in the southwest to the Colorado River in the northeast (sheet 2). The Edwards-Trinity aquifer system spans four geographic subareas: Trans-Pecos, Edwards Plateau, Hill Country, and Balcones fault zone (fig. 1). The names of all aquifers in the study area were adopted for RASA purposes directly from nomenclature mandated by the Texas Water Plan (Texas Water Development Board, 1990).

  9. Altitudes and thicknesses of hydrogeologic units of the Ozark Plateaus aquifer system in Arkansas, Kansas, Missouri, and Oklahoma

    Science.gov (United States)

    Westerman, Drew A.; Gillip, Jonathan A.; Richards, Joseph M.; Hays, Phillip D.; Clark, Brian R.

    2016-09-29

    A hydrogeologic framework was constructed to represent the altitudes and thicknesses of hydrogeologic units within the Ozark Plateaus aquifer system as part of a regional groundwater-flow model supported by the U.S. Geological Survey Water Availability and Use Science Program. The Ozark Plateaus aquifer system study area is nearly 70,000 square miles and includes parts of Arkansas, Kansas, Missouri, and Oklahoma. Nine hydrogeologic units were selected for delineation within the aquifer system and include the Western Interior Plains confining system, the Springfield Plateau aquifer, the Ozark confining unit, the Ozark aquifer, which was divided into the upper, middle, and lower Ozark aquifers to better capture the spatial variation in the hydrologic properties, the St. Francois confining unit, the St. Francois aquifer, and the basement confining unit. Geophysical and well-cutting logs, along with lithologic descriptions by well drillers, were compiled and interpreted to create hydrologic altitudes for each unit. The final compiled dataset included more than 23,000 individual altitude points (excluding synthetic points) representing the nine hydrogeologic units within the Ozark Plateaus aquifer system.

  10. Conceptual and numerical models of the glacial aquifer system north of Aberdeen, South Dakota

    Science.gov (United States)

    Marini, Katrina A.; Hoogestraat, Galen K.; Aurand, Katherine R.; Putnam, Larry D.

    2012-01-01

    This U.S. Geological Survey report documents a conceptual and numerical model of the glacial aquifer system north of Aberdeen, South Dakota, that can be used to evaluate and manage the city of Aberdeen's water resources. The glacial aquifer system in the model area includes the Elm, Middle James, and Deep James aquifers, with intervening confining units composed of glacial till. The Elm aquifer ranged in thickness from less than 1 to about 95 feet (ft), with an average thickness of about 24 ft; the Middle James aquifer ranged in thickness from less than 1 to 91 ft, with an average thickness of 13 ft; and the Deep James aquifer ranged in thickness from less than 1 to 165 ft, with an average thickness of 23 ft. The confining units between the aquifers consisted of glacial till and ranged in thickness from 0 to 280 ft. The general direction of groundwater flow in the Elm aquifer in the model area was from northwest to southeast following the topography. Groundwater flow in the Middle James aquifer was to the southeast. Sparse data indicated a fairly flat potentiometric surface for the Deep James aquifer. Horizontal hydraulic conductivity for the Elm aquifer determined from aquifer tests ranged from 97 to 418 feet per day (ft/d), and a confined storage coefficient was determined to be 2.4x10-5. Estimates of the vertical hydraulic conductivity of the sediments separating the Elm River from the Elm aquifer, determined from the analysis of temperature gradients, ranged from 0.14 to 2.48 ft/d. Average annual precipitation in the model area was 19.6 inches per year (in/yr), and agriculture was the primary land use. Recharge to the Elm aquifer was by infiltration of precipitation through overlying outwash, lake sediments, and glacial till. The annual recharge for the model area, calculated by using a soil-water-balance method for water year (WY) 1975-2009, ranged from 0.028 inch in WY 1980 to 4.52 inches in WY 1986, with a mean of 1.56 inches. The annual potential

  11. Strategy for solving semi-analytically three-dimensional transient flow in a coupled N-layer aquifer system

    NARCIS (Netherlands)

    Veling, E.J.M.; Maas, C.

    2008-01-01

    Efficient strategies for solving semi-analytically the transient groundwater head in a coupled N-layer aquifer system phi(i)(r, z, t), i = 1, ..., N, with radial symmetry, with full z-dependency, and partially penetrating wells are presented. Aquitards are treated as aquifers with their own horizont

  12. Geochemical impacts of groundwater heat pump systems in an urban alluvial aquifer with evaporitic bedrock.

    Science.gov (United States)

    Garrido Schneider, Eduardo A; García-Gil, Alejandro; Vázquez-Suñè, Enric; Sánchez-Navarro, José Á

    2016-02-15

    In the last decade, there has been an extensive use of shallow geothermal exploitations in urban environments. Although the thermal interference between exploitations has been recently studied, there is a lack of knowledge regarding the geochemical impacts of those systems on the aquifers where they are installed. Groundwater flow line scale and well-doublet scale research work has been conducted at city scale to quantify the geochemical interaction of shallow geothermal exploitations with the environment. A comprehensive analysis was conducted on data obtained from a monitoring network specifically designed to control and develop aquifer policies related to thermal management of the aquifer. The geochemical impacts were evaluated from a thermodynamic point of view by means of saturation index (SI) calculations with respect to the different mineral species considered in the system. The results obtained indicate limited geochemical interaction with the urban environment in most of the situations. However, there are some cases where the interaction of the groundwater heat pump installations with the evaporitic bedrock resulted in the total disablement of the exploitation system operation wells. The application of the tool proposed proved to be pragmatic in the evaluation of geochemical impacts. Injection of water into the aquifer can trigger an important bedrock gypsum and halite dissolution process that is partly responsible for scaling in well casing pipes and collapse of the terrain in the vicinity of injection wells. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Wells measured for water-levels, unconfined and confined aquifers, Wood River Valley aquifer system, south-central Idaho, October 2006 and October 2012.

    Data.gov (United States)

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

  14. Changes in the water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2006 to October 2012.

    Data.gov (United States)

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

  15. Changes in the potentiometric-surface altitude of the confined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2006 to October 2012.

    Data.gov (United States)

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

  16. Major geochemical processes in the evolution of carbonate-Aquifer systems

    Science.gov (United States)

    Hanshaw, B.B.; Back, W.

    1979-01-01

    -reefs, where reflux dolomites may form, highly alkaline, on-shore and continental lakes, and sabkha flats; these dolomites are typically associated with evaporite minerals. However, these processes cannot account for most of the regionally extensive dolomites in the geologic record. A major environment of regional dolomitization is in the mixing zone (zone of dispersion) where profound changes in mineralogy and redistribution of porosity and permeability occur from the time of early emergence and continuing through the time when the rocks are well-developed aquifers. The reactions and processes, in response to mixing waters of differing chemical composition, include dissolution and precipitation of carbonate minerals in addition to dolomitization. An important control on permeability distribution in a mature aquifer system is the solution of dolomite with concomitant precipitation of calcite in response to gypsum dissolution (dedolomitization). Predictive models developed by mass-transfer calculations demonstrate the controlling reactions in aquifer systems through the constraints of mass balance and chemical equilibrium. An understanding of the origin, chemistry, mineralogy and environments of deposition and accumulation of carbonate minerals together with a comprehension of diagenetic processes that convert the sediments to rocks and geochemical, tectonic and hydrologic phenomena that create voids are important to hydrologists. With this knowledge, hydrologists are better able to predict porosity and permeability distribution in order to manage efficiently a carbonate-aquifer system. ?? 1979.

  17. An Aquifer Storage and Recovery system with reclaimed wastewater to preserve native groundwater resources in El Paso, Texas.

    Science.gov (United States)

    Sheng, Zhuping

    2005-06-01

    The traditional concept of Aquifer Storage and Recovery (ASR) has been emphasized and extensively applied for water resources conservation in arid and semi-arid regions using groundwater systems as introduced in Pyne's book titled Groundwater Recharge and Wells. This paper extends the ASR concept to an integrated level in which either treated or untreated surface water or reclaimed wastewater is stored in a suitable aquifer through a system of spreading basins, infiltration galleries and recharge wells; and part or all of the stored water is recovered through production wells, dual function recharge wells, or by streams receiving increased discharge from the surrounding recharged aquifer as needed. In this paper, the author uses the El Paso Water Utilities (EPWU) ASR system for injection of reclaimed wastewater into the Hueco Bolson aquifer as an example to address challenges and resolutions faced during the design and operation of an ASR system under a new ASR system definition. This new ASR system concept consists of four subsystems: source water, storage space-aquifer, recharge facilities and recovery facilities. Even though facing challenges, this system has successfully recharged approximately 74.7 million cubic meters (19.7 billion gallons) of reclaimed wastewater into the Hueco Bolson aquifer through 10 recharge wells in the last 18 years. This ASR system has served dual purposes: reuse of reclaimed wastewater to preserve native groundwater, and restoration of groundwater by artificial recharge of reclaimed wastewater into the Hueco Bolson aquifer.

  18. Modeling complex aquifer systems: a case study in Baton Rouge, Louisiana (USA)

    Science.gov (United States)

    Pham, Hai V.; Tsai, Frank T.-C.

    2017-05-01

    This study targets two challenges in groundwater model development: grid generation and model calibration for aquifer systems that are fluvial in origin. Realistic hydrostratigraphy can be developed using a large quantity of well log data to capture the complexity of an aquifer system. However, generating valid groundwater model grids to be consistent with the complex hydrostratigraphy is non-trivial. Model calibration can also become intractable for groundwater models that intend to match the complex hydrostratigraphy. This study uses the Baton Rouge aquifer system, Louisiana (USA), to illustrate a technical need to cope with grid generation and model calibration issues. A grid generation technique is introduced based on indicator kriging to interpolate 583 wireline well logs in the Baton Rouge area to derive a hydrostratigraphic architecture with fine vertical discretization. Then, an upscaling procedure is developed to determine a groundwater model structure with 162 layers that captures facies geometry in the hydrostratigraphic architecture. To handle model calibration for such a large model, this study utilizes a derivative-free optimization method in parallel computing to complete parameter estimation in a few months. The constructed hydrostratigraphy indicates the Baton Rouge aquifer system is fluvial in origin. The calibration result indicates hydraulic conductivity for Miocene sands is higher than that for Pliocene to Holocene sands and indicates the Baton Rouge fault and the Denham Springs-Scotlandville fault to be low-permeability leaky aquifers. The modeling result shows significantly low groundwater level in the "2,000-foot" sand due to heavy pumping, indicating potential groundwater upward flow from the "2,400-foot" sand.

  19. Isotope geochemistry and modelling of the multi-aquifer system in the eastern part of Lithuania

    Science.gov (United States)

    Mokrik, Robert; Juodkazis, Vytautas; Štuopis, Anicetas; Mažeika, Jonas

    2014-06-01

    A steady-state groundwater flow model of three Quaternary intertill aquifers in the eastern part of Lithuania has been compiled. The distinction of separate modelled layers is based on hydraulic and isotope-hydrochemistry data criteria. 3H data were used to estimate the corrected groundwater age and were coupled with a groundwater-flow-dynamics model of the Quaternary aquifer system along a cross-section flow pathway from the Baltic Upland recharge area in eastern Lithuania towards the discharge area in the lowlands near the city of Kaunas in central Lithuania. The bicarbonate content in groundwater (214-462 mg/l) increases downgradient towards the lowland area. The other major constituents and total dissolved solids (TDS) have a trend analogous to the bicarbonate. The 14C activity of dissolved inorganic carbon (DIC) in the groundwater ranges from 41.4 to 85.7 pMC. With aquifer-system depth, active precipitation of aqueous solution takes place by dissolving minerals of calcite and dolomite and leakage of "old" groundwater from lower aquifers; the process is also traced by lower 14C and 3H activities and by more positive δ18O values in lowland areas.

  20. A quantitative analysis of hydraulic interaction processes in stream-aquifer systems.

    Science.gov (United States)

    Wang, Wenke; Dai, Zhenxue; Zhao, Yaqian; Li, Junting; Duan, Lei; Wang, Zhoufeng; Zhu, Lin

    2016-01-28

    The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources.

  1. The quality of our Nation's waters: water quality in the glacial aquifer system, northern United States, 1993-2009

    Science.gov (United States)

    Warner, Kelly L.; Ayotte, Joseph D.

    2015-01-01

    The glacial aquifer system underlies much of the northern United States. About one-sixth (41 million people) of the United States population relies on the glacial aquifer system for drinking water. The primary importance of the glacial aquifer system is as a source of water for public supply to the population centers in the region, but the aquifer system also provides drinking water for domestic use to individual homes and small communities in rural areas. Withdrawals from this aquifer system for public supply are the largest in the Nation and play a key role in the economic development of parts of 26 States. Corn production has increased in the central part of the aquifer system over the last 10 years, and the increased production increases the need for water for agricultural use and the need for increased use of agrochemicals. Additionally, the steady increase in population (15 million people over the last 40 years) in urban and rural areas is resulting in an increased reliance on the glacial aquifer system for high-quality drinking water. The need to monitor, understand, and maintain the water quality of this valuable economic resource continues to grow.

  2. Salinization processes in a coastal aquifer system (Siracusa, Italy)

    Science.gov (United States)

    Rapti Caputo, D.; Vaccaro, C.

    2003-04-01

    The Syracuse area (Southeastern Sicily, Italy) is famous since ancient times for its natural springs, like Aretusa and Ciane, as well as for the hydraulic management handicraft know from 480 B.C. Unfortunately, the recent hyper-exploitation of the underground water resources and the concomitant decrease of the precipitations caused a general lowering of the piezometric level of the aquifers therefore enhancing the intrusion of marine salty waters. In the present work, numerous hydrochemical parameters have been investigated, among which the pH, the total dissolved solid, the electric conductivity, the temperature and the concentration of Ca, Mg, Na, K, HCO3, Cl and SO4. The data have been collected from five well fields located at different distances from the coast. Analyses have been performed in order to understand the relationships between the intense exploitation and the geochemical characteristics of the underground water resources. Our results obtained by applying classical geochemical methodologies integrated with techniques of multivariate statistics emphasise, firstly, the predominance of the Ca-HCO3 hydrochemical facies. Secondly, we could determine the evolution of mixing phenomena between salty and fresh waters approaching the coast line (San Nicola field). This behaviour is mainly associated to the pumping increase. Obviously, this intrusive process characterised by chlorides concentrations larger than 2000 mg/l affects all the coastal natural environment and generates severe problems to the entire aqueduct network.

  3. Integrating Predictive Modeling with Control System Design for Managed Aquifer Recharge and Recovery Applications

    Science.gov (United States)

    Drumheller, Z. W.; Regnery, J.; Lee, J. H.; Illangasekare, T. H.; Kitanidis, P. K.; Smits, K. M.

    2014-12-01

    Aquifers around the world show troubling signs of irreversible depletion and seawater intrusion as climate change, population growth, and urbanization led to reduced natural recharge rates and overuse. Scientists and engineers have begun to re-investigate the technology of managed aquifer recharge and recovery (MAR) as a means to increase the reliability of the diminishing and increasingly variable groundwater supply. MAR systems offer the possibility of naturally increasing groundwater storage while improving the quality of impaired water used for recharge. Unfortunately, MAR systems remain wrought with operational challenges related to the quality and quantity of recharged and recovered water stemming from a lack of data-driven, real-time control. Our project seeks to ease the operational challenges of MAR facilities through the implementation of active sensor networks, adaptively calibrated flow and transport models, and simulation-based meta-heuristic control optimization methods. The developed system works by continually collecting hydraulic and water quality data from a sensor network embedded within the aquifer. The data is fed into an inversion algorithm, which calibrates the parameters and initial conditions of a predictive flow and transport model. The calibrated model is passed to a meta-heuristic control optimization algorithm (e.g. genetic algorithm) to execute the simulations and determine the best course of action, i.e., the optimal pumping policy for current aquifer conditions. The optimal pumping policy is manually or autonomously applied. During operation, sensor data are used to assess the accuracy of the optimal prediction and augment the pumping strategy as needed. At laboratory-scale, a small (18"H x 46"L) and an intermediate (6'H x 16'L) two-dimensional synthetic aquifer were constructed and outfitted with sensor networks. Data collection and model inversion components were developed and sensor data were validated by analytical measurements.

  4. The Impact of Integrated Aquifer Storage and Recovery and Brackish Water Reverse Osmosis (ASRRO on a Coastal Groundwater System

    Directory of Open Access Journals (Sweden)

    Steven Eugenius Marijnus Ros

    2017-04-01

    Full Text Available Aquifer storage and recovery (ASR of local, freshwater surpluses is a potential solution for freshwater supply in coastal areas, as is brackish water reverse osmosis (BWRO of relatively shallow groundwater in combination with deeper membrane concentrate disposal. A more sustainable and reliable freshwater supply may be achieved by combining both techniques in one ASRRO system using multiple partially penetrating wells (MPPW. The impact of widespread use of ASRRO on a coastal groundwater system was limited based on regional groundwater modelling but it was shown that ASRRO decreased the average chloride concentration with respect to the autonomous scenario and the use of BWRO. ASRRO was successful in mitigating the local negative impact (saltwater plume formation caused by the deep disposal of membrane concentrate during BWRO. The positive impacts of ASRRO with respect to BWRO were observed in the aquifer targeted for ASR and brackish water abstraction (Aquifer 1, but foremost in the deeper aquifer targeted for membrane concentrate disposal (Aquifer 2. The formation of a horizontal freshwater barrier was found at the top of both aquifers, reducing saline seepage. The disposal of relatively fresh concentrate in Aquifer 2 led to brackish water outflow towards the sea. The net abstraction in Aquifer 1 enforced saltwater intrusion, especially when BWRO was applied. The conclusion of this study is that ASRRO can provide a sustainable alternative for BWRO.

  5. Improved aquifer characterization and the optimization of the design of brackish groundwater desalination systems

    KAUST Repository

    Malivaa, Robert G.

    2011-07-01

    Many water scarce regions possess brackish-water resources that can be desalted to provide alternative water supplies. Brackish groundwater desalination by reverse osmosis (RO) is less expensive than seawater systems because of reduced energy and pretreatment requirements and lesser volumes of concentrate that require disposal. Development of brackish groundwater wellfields include the same hydraulic issues that affect conventional freshwater wellfields. Managing well interference and prevention of adverse impacts such as land subsidence are important concerns. RO systems are designed to treat water whose composition falls within a system-specific envelope of salinities and ion concentrations. A fundamental requirement for the design of brackish groundwater RO systems is prediction of the produced water chemistry at both the start of pumping and after 10-20 years of operation. Density-dependent solute-transport modeling is thus an integral component of the design of brackish groundwater RO systems. The accuracy of groundwater models is dependent upon the quality of the hydrogeological data upon which they are based. Key elements of the aquifer characterization are the determination of the three-dimensional distribution of salinity within the aquifer and the evaluation of aquifer heterogeneity with respect to hydraulic conductivity. It is necessary to know from where in a pumped aquifer (or aquifer zone) water is being produced and the contribution of vertical flow to the produced water. Unexpected, excessive vertical migration (up-coning) of waters that are more saline has adversely impacted some RO systems because the salinity of the water delivered to the system exceeded the system design parameters. Improved aquifer characterization is possible using advanced geophysical techniques, which can, in turn, lead to more accurate solute-transport models. Advanced borehole geophysical logs, such as nuclear magnetic resonance, were run as part of the exploratory test

  6. Vulnerability of low-arsenic aquifers to municipal pumping in Bangladesh

    Science.gov (United States)

    Knappett, P. S. K.; Mailloux, B. J.; Choudhury, I.; Khan, M. R.; Michael, H. A.; Barua, S.; Mondal, D. R.; Steckler, M. S.; Akhter, S. H.; Ahmed, K. M.; Bostick, B.; Harvey, C. F.; Shamsudduha, M.; Shuai, P.; Mihajlov, I.; Mozumder, R.; van Geen, A.

    2016-08-01

    Sandy aquifers deposited >12,000 years ago, some as shallow as 30 m, have provided a reliable supply of low-arsenic (As) drinking water in rural Bangladesh. This study concerns the potential risk of contaminating these aquifers in areas surrounding the city of Dhaka where hydraulic heads in aquifers >150 m deep have dropped by 70 m in a few decades due to municipal pumping. Water levels measured continuously from 2012 to 2014 in 12 deep (>150 m), 3 intermediate (90-150 m) and 6 shallow (hydraulic gradients in the deep aquifer system ranged from 1.7 × 10-4 to 3.7 × 10-4 indicating flow towards Dhaka throughout 2012-2014. Vertical recharge on the edge of the drawdown cone was estimated at 0.21 ± 0.06 m/yr. The data suggest that continued municipal pumping in Dhaka could eventually contaminate some relatively shallow community wells.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-04-01

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

  8. Modelling Contributions of the Local and Regional Groundwater Flow of Managed Aquifer Recharge Activities at Querença-Silves Aquifer System.

    Science.gov (United States)

    Costa, Luís; Monteiro, José Paulo; Oliveira, Manuel; Mota, Rogério; Lobo-Ferreira, João Paulo; Martins de Carvalho, José; Martins de Carvalho, Tiago; Agostinho, Rui; Hugman, Rui

    2015-04-01

    The Querença-Silves (QS) aquifer system is one of the most important natural groundwater reservoirs in the Algarve region of southern Portugal. With a surface area of 324 km2, this karst aquifer system is the main source of supply for irrigation as well as an important source of water for the urban supply. Due to the importance given to QS aquifer system by both governmental actors and end users, ongoing research during the last two decades at the University of Algarve has attempted to provide a better understanding of the hydrogeology and hydraulic behavior, which has resulted in the development of regional scale numerical models. The most recent hydrogeological data has been acquired during the ongoing MARSOL project (MARSOL-GA-2013-619120) which aims to demonstrate that Managed Aquifer Recharge (MAR) is a sound, safe and sustainable strategy that can be applied with great confidence in finding solutions to water scarcity in Southern Europe. Within the scope of the project large diameter well injection tests (with and without tracers) as well as geophysical surveys have been carried out in order to determine the infiltration capacity and aquifer properties. The results of which allowed the use of analytical methods to determine local scale values of hydraulic parameters (e.g. hydraulic conductivity and storage coefficient). These values will be compared with results from pre-existing numerical flow and transport models in order to obtain complementary solutions to the problem at local and regional scales. This analysis will contribute to the selection of the most appropriate methods to interpret, reproduce and model the impacts of MAR activities planned within the scope of the MARSOL project. Subsequent to the planned injection tests and, with the support of modelling efforts, the capacity of infiltration of rejected water from water treatment plants or surface storage dams in the large diameter well will be assessed.

  9. Numerical simulation of groundwater flow for the Yakima River basin aquifer system, Washington

    Science.gov (United States)

    Ely, D.M.; Bachmann, M.P.; Vaccaro, J.J.

    2011-01-01

    A regional, three-dimensional, transient numerical model of groundwater flow was constructed for the Yakima River basin aquifer system to better understand the groundwater-flow system and its relation to surface-water resources. The model described in this report can be used as a tool by water-management agencies and other stakeholders to quantitatively evaluate proposed alternative management strategies that consider the interrelation between groundwater availability and surface-water resources.

  10. Storm impacts on a high energy sandy beach system, northwest Ireland: short (event) to long term (decadal) behaviour

    Science.gov (United States)

    Guisado-Pintado, Emilia; Jackson, Derek; Cooper, Andrew; O'Connor, Marianne

    2017-04-01

    system at the northern part of the site over the medium to long term. We also observe that modal conditions favour intertidal beach recovery in the short and medium term, with a resulting southerly drift of sediment with an offshore return of sediment via the ebb-channel (multi-year response). This work demonstrates that coastal hazard analysis, approached at an appropriate site-specific scale and with suitable numerical modelling and field techniques, must include capturing data on nearshore forcing parameters that are driving shoreline response over various timescales. Understanding of these nearshore and intertidal morphodynamics is an important prelude to examining how a sandy shoreline behaves in response to high energy forcing. We advocate that morphodynamic self-adjustment of the beach system to a set of varying climatic conditions associated with increases in storminess, will have important implications for future coastline response.

  11. Geochemistry at the sulfate reduction-methanogenesis transition zone in an anoxic aquifer

    DEFF Research Database (Denmark)

    Jakobsen, Rasmus; Cold, L.

    2007-01-01

    The study addresses a 10 m deep phreatic postglacial sandy aquifer of vertically varying lithology and horizontally varying infiltration water chemistry, displaying calcite dissolution, ion-exchange, and anaerobic redox processes. The simple variations in lithology and infiltration combine into a...... by implementing specific energy yields for the microbial redox processes, could explain most of the observed groundwater geochemistry as an expression of a closely coupled system of mineral equilibria and redox processes occurring at partial equilibrium....

  12. Geochemistry of the Floridan aquifer system in Florida and in parts of Georgia, South Carolina, and Alabama

    Science.gov (United States)

    Sprinkle, Craig L.

    1989-01-01

    The chemical quality of the ground water in the Floridan aquifer system is determined primarily by mineral-water interaction. However, some changes in water quality have been imposed by development, particularly near coastal pumping centers. A total of 601 chemical analyses, all from different wells, most completed in the upper part of the aquifer system, were used to describe the variations in water chemistry and to study the processes responsible for observed changes. The Floridan aquifer system is a vertically continuous sequence of Tertiary carbonate rocks that are of generally high permeability and are hydraulically connected in varying degrees. The rocks are principally limestone and dolomite, but they grade into limy sands and clays near the aquifer system's updip limits. Major minerals in the aquifer system are calcite, dolomite, and, locally, gypsum or quartz; minor minerals include apatite, glauconite, and clay minerals such as kaolinite and montmorillonite. Trace amounts of metallic oxides or sulfides are present in some areas. The aquifer system consists of the Upper and Lower Floridan aquifers, separated in most places by a less permeable confining unit that has highly variable hydraulic properties. Only the Upper Floridan aquifer is present throughout the study area. Freshwater enters the aquifer system in outcrop areas located primarily in central Georgia and north-central Florida. Discharge occurs chiefly to streams and springs and, to a lesser extent, directly into the sea. Most of the flow into and out of the system takes place where it is unconfined or where the upper confining unit is thin. Secondary permeability developed by dissolution of aquifer material is most prominent in these areas of dynamic flow. Dissolved-solids concentrations in water from the Upper Floridan aquifer generally range from less than 25 milligrams per liter near outcrops to more than 25,000 milligrams per liter along the coasts. The dominant cations in the ground water

  13. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions depicting saline areas within the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  14. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface generated for the "freshwater" thickness of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  15. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions of the upper confining unit of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  16. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Geologic units forming the base of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  17. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the top of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  18. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the base of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  19. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Geologic units forming the top of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  20. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Point features used for the base of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  1. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for top of the middle confining unit of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  2. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon region depicting the weathered limestone residuum of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  3. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the thickness of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  4. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  5. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygons representing thickness of the upper confining unit of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  6. A Regional Strategy for the Assessment and Management of Transboundary Aquifer Systems in the Americas

    Science.gov (United States)

    Hanson, R. T.; Rivera, A.; Tujchneider, O.; Guillén, C.; Campos, M.; Da Franca, N.; May, Z.; Aureli, A.

    2015-12-01

    The UNESCO-IHP ISARM-Americas technical committee has developed a regional strategy for the assessment and management of transboundary aquifer systems in the Americas as part of their ongoing cooperative assistance to help neighboring countries sustain water resources and reduce potential conflict. The fourth book in the series of publications sponsored by UNESCO and OAS documents this strategy. The goal of this strategy is the collective understanding, developing, managing, and protecting of the transboundary aquifers in the Americas This strategy includes technical, social, and governance recommendations for an integrated resource management of groundwater based on flexible arrangements that not only manage but also demand social participation in solving problems, consider changes in land use and water use and promote the increase of water sustainability for all transboundary neighbors. The successful implementation of this strategy starts with sharing information of the status and use of land and water as well as intergovernmental partnerships to link science and policy with existing instruments for managing the water resources. International organizations such as UNESCO and OAS also can help facilitate the development of transboundary agreements and establish cooperation on transboundary aquifers between neighbors. The UNESCO-IHP ISARM-Americas technical committee has been successful in creating a network of partners from 24 countries and in translating existing aquifer knowledge into a meaningful strategy for the American hemisphere. The strategy aims to explain and develop the role of science and the informed-decision approach. Examples from North and South America show how the process has begun to develop for selected transboundary aquifers. These include the Milk River basin between the US and Canada, the Rio Grande and Colorado River basins between the US and Mexico, and the Guarani River basin in South America.

  7. Integrated monitoring technologies for the management of a Soil-Aquifer-Treatment (SAT) system

    Science.gov (United States)

    Kallioras, Andreas; Kofakis, Petros; Bumberger, Jan; Athanasiou, Georgios; Schimdt, Felix; Apostolopoulos, Georgios; Uzunoglou, Nikolaos; Dietrich, Peter; Schuth, Christoph

    2015-04-01

    Artificial recharge of groundwater has an important role to play in water reuse as treated wastewater effluent can be infiltrated into the ground for aquifer recharge. As the effluent moves through the soil and the aquifer, it undergoes significant quality improvements through physical, chemical, and biological processes in the underground environment. Collectively, these processes and the water quality improvement obtained are called soil-aquifer-treatment (SAT) or geopurification. The pilot site of Lavrion Technological & Cultural Park (LTCP) of the National Technical University of Athens (NTUA), involves the employment of plot infiltration basins at experimental scale, which will be using waters of impaired quality as a recharge source, and hence acting as a Soil-Aquifer-Treatment, SAT, system. Τhe LTCP site will be employed as a pilot SAT system complemented by new technological developments, which will be providing continuous monitoring of the quantitative and qualitative characteristics of infiltrating groundwater through all hydrologic zones (i.e. surface, unsaturated and saturated zone). This will be achieved by the development and installation of an integrated system of prototype sensing technologies, installed on-site, and offering a continuous evaluation of the performance of the SAT system. An integrated approach of the performance evaluation of any operating SAT system should aim at parallel monitoring of all hydrologic zones, proving the sustainability of all involved water quality treatment processes within unsaturated and saturated zone. Hence a prototype system of Time and Frequency Domain Reflectometry (TDR & FDR) sensors is developed and will be installed, in order to achieve continuous quantitative monitoring of the unsaturated zone through the entire soil column down to significant depths below the SAT basin. Additionally, the system contains two different radar-based sensing systems that will be offering (i) identification of preferential

  8. MANAGEMENT MODEL OF UNCONFINED AQUIFER SYSTEM WITH SMALL THICKNESS WITH RESPECT TO DRAWDOWN BASED ON TWO-LEVEL RESPONSE MATRIX

    Institute of Scientific and Technical Information of China (English)

    Cai-Zhi SUN; Wei ZOU; Xue-Yu LIN

    2004-01-01

    In the management of unconfined aquifer systems, if the thickness of the aquifer is very small and the drawdown is relatively big, errors may arise when the superposition principle is adopted.directly. In allusion to this limitation, a new management model for the management of unconfined aquifer systems called two-level response matrix method is put forward. This method is applied in groundwater resources management in Shenyang city. The managing results show that this methodcan, in some degree, increase the efficiency of management and decrease the risk of management.

  9. The quality of our Nation's waters: water quality in the Mississippi embayment-Texas coastal uplands aquifer system and Mississippi River Valley alluvial aquifer, south-central United States, 1994-2008

    Science.gov (United States)

    Kingsbury, James A.; Barlow, Jeannie R.; Katz, Brian G.; Welch, Heather L.; Tollett, Roland W.; Fahlquist, Lynne S.

    2015-01-01

    About 8 million people rely on groundwater from the Mississippi embayment—Texas coastal uplands aquifer system for drinking water. The Mississippi River Valley alluvial aquifer also provides drinking water for domestic use in rural areas but is of primary importance to the region as a source of water for irrigation. Irrigation withdrawals from this aquifer are among the largest in the Nation and play a key role in the economy of the area, where annual crop sales total more than $7 billion. The reliance of the region on both aquifers for drinking water and irrigation highlights the importance of long-term management to sustain the availability and quality of these resources.

  10. Integrated monitoring technologies for the management of a Soil-Aquifer-Treatment (SAT) system.

    Science.gov (United States)

    Papadopoulos, Alexandros; Kallioras, Andreas; Kofakis, Petros; Bumberger, Jan; Schmidt, Felix; Athanasiou, Georgios; Uzunoglou, Nikolaos; Amditis, Angelos; Dietrich, Peter

    2016-04-01

    Artificial recharge of groundwater has an important role to play in water reuse as treated wastewater effluent can be infiltrated into the ground for aquifer recharge. As the effluent moves through the soil and the aquifer, it undergoes significant quality improvements through physical, chemical, and biological processes in the underground environment. Collectively, these processes and the water quality improvement obtained are called soil-aquifer-treatment (SAT) or geopurification. The pilot site of Lavrion Technological & Cultural Park (LTCP) of the National Technical University of Athens (NTUA), involves the employment of plot infiltration basins at experimental scale, which will be using waters of impaired quality as a recharge source, and hence acting as a Soil-Aquifer-Treatment, SAT, system. Τhe LTCP site will be employed as a pilot SAT system complemented by new technological developments, which will be providing continuous monitoring of the quantitative and qualitative characteristics of infiltrating groundwater through all hydrologic zones (i.e. surface, unsaturated and saturated zone). This will be achieved by the development and installation of an integrated system of prototype sensing technologies, installed on-site, and offering a continuous evaluation of the performance of the SAT system. An integrated approach of the performance evaluation of any operating SAT system should aim at parallel monitoring of all hydrologic zones, proving the sustainability of all involved water quality treatment processes within unsaturated and saturated zone. Hence a prototype system of Time and Frequency Domain Reflectometry (TDR & FDR) sensors is developed and will be installed, in order to achieve continuous quantitative monitoring of the unsaturated zone through the entire soil column down to significant depths below the SAT basin. Additionally, the system contains two different radar-based sensing systems that will be offering (i) identification of preferential

  11. Groundwater withdrawal rates from the Ozark Plateaus aquifer system, 1900 to 2010

    Science.gov (United States)

    Knierim, Katherine J.; Nottmeier, Anna M.; Worland, Scott C.; Westerman, Drew A.; Clark, Brian R.

    2016-01-01

    Groundwater is an often overlooked freshwater resource compared to surface water, but groundwater is used widely across the United States, especially during periods of drought. If groundwater models can successfully simulate past conditions, they may be used to evaluate potential future pumping scenarios or climate conditions, thus providing a valuable planning tool for water-resource managers. Quantifying the groundwater-use component for a groundwater model is a vital but often challenging endeavor. This dataset includes groundwater withdrawal rates modeled for the Ozark Plateaus aquifer system (Ozark system) from 1900 to 2010 by groundwater model cell (2.6 square kilometers) for five water-use divisions—agriculture (including irrigation and aquaculture), livestock, public supply (including municipal and rural water districts), and non-agriculture (including thermoelectric power generation, mining, commercial, and industrial)—and by country for domestic (self-supplied) use. Two child items are included with the dataset: “Domestic groundwater withdrawal rates from the Ozark Plateaus aquifer system, 1900 to 2010” and “Public supply, non-agriculture, livestock, and agriculture groundwater withdrawal rates from the Ozark Plateaus aquifer system, 1900 to 2010”. The Ozark system is located in the central United States and is composed of interbedded Cambrian to Pennsylvanian clastic and carbonate lithologies. In stratigraphic order, the Ozark system includes the Basement confining unit, St. Francois aquifer, St. Francois confining unit, Ozark aquifer, Ozark confining unit, Springfield Plateau aquifer, and Western Interior Plains confining system. Generally, the lower portion of the Ozark aquifer is the primary source of groundwater across much of Missouri and the Springfield Plateau aquifer is used across northern Arkansas. A full description of the methods used to model groundwater withdrawal rates from the Ozark system are available in Knierim et al., IN

  12. Numerical modeling of geothermal groundwater flow in karst aquifer system in eastern Weibei, Shaanxi Province, China

    Institute of Scientific and Technical Information of China (English)

    LI Ming; LI GuoMin; YANG Liao; DANG XueYa; ZHAO ChunHu; HOU GuangCai; ZHANG MaoSheng

    2007-01-01

    The quantitative assessment of geothermal water resources is important to the exploitation and utilization of geothermal resources. In the geothermal water systems the density of groundwater changes with the temperature, therefore the variations in hydraulic heads and temperatures are very complicated. A three-dimensional density-dependent model coupling the groundwater flow and heat transport is established and used to simulate the geothermal water flow in the karst aquifers in eastern Weibei,Shaanxi Province, China. The multilayered karst aquifer system in the study area is cut by some major faults which control the regional groundwater flow. In order to calibrate and simulate the effect of the major faults, each fault is discretized as a belt of elements with special hydrological parameters in the numerical model. The groundwater dating data are used to be integrated with the groundwater flow pattern and calibrate the model. Simulation results show that the calculated hydraulic heads and temperature fit with the observed data well.

  13. The origin of barium in the Cambrian–Vendian aquifer system, North Estonia

    Directory of Open Access Journals (Sweden)

    Mokrik, Robert

    2009-09-01

    Full Text Available Identification of the barium occurrence and its origin is made on the basis of the groundwater chemistry study. High Ba content has been detected in the Cambrian–Vendian aquifer system in the coastal vicinity of the Gulf of Finland in Estonia and St Petersburg. The dissolution of Ba from witherite as the primary source was derived from the analysis of the aqueous solution equilibrium with Ba-related minerals. It is reflected in the chemical composition of groundwater and influenced by the galenite–calcite–fluorite polymetallic mineralization in Vendian sandstones. The dissolution and re-deposition of carbonates and baryte are confirmed by mineral saturation states for an aqueous solution and distribution of other species in the groundwater of the Cambrian–Vendian aquifer system in North Estonia.

  14. Assessing the performance of a permeable reactive barrier-aquifer system using a dual-domain solute transport model

    Science.gov (United States)

    Chen, Jui-Sheng; Hsu, Shao-Yiu; Li, Ming-Hsu; Liu, Chen-Wuing

    2016-12-01

    Transport behavior through a permeable reactive barrier (PRB)-aquifer system is complicated because of the different physical and chemical properties of the PRB and the aquifer. Dual-domain solute transport models are efficient tools for better understanding the various processes and mechanisms of reactive solute transport through a PRB-aquifer system. This study develops a dual-domain analytical model to assess the physical and chemical processes of two-dimensional reactive solute transport through a PRB-aquifer system. The dispersion processes of a dual-domain system on the solute transport are investigated. The results show that the dispersion parameters in a dual-domain system synchronously govern the dynamic shape of the contaminant plume. The low longitudinal and transverse dispersion coefficients of a dual-domain system may restrict the spreading of the plume and elevate the plume's concentration level. The derived analytical solution is applied to explore how the different reactive transport processes affect the performance of a PRB-aquifer system. The results show that the first-order decay rate constant of the PRB has a critical effect on the performance of the PRB-aquifer system, whereas the effects of the physical dispersion properties on PRB performance are less significant.

  15. A semi-analytical model for predicting water quality from an aquifer storage and recovery system

    Science.gov (United States)

    Sedighi, Ali; Klammler, Harald; Brown, Chris; Hatfield, Kirk

    2006-10-01

    SummaryAquifer storage and recovery (ASR) involves the injection of freshwater in an aquifer through wells for the purpose of creating a subsurface water supply that is recovered at a later time, often using the same wells, to meet seasonal, long-term, emergency, or other demands. In this paper a numerically efficient semi-analytical model is developed for predicting the quality of water recovered by an ASR system given data on the qualities of ambient and injected waters, hydraulic properties of the aquifer, ambient hydraulic gradient, and system operations. It is assumed the ASR well is installed in a stratified aquifer such that the semi-analytical ASR model (SASRM) simulates the fate of water injected under steady-state conditions into each stratum. It is also assumed that a sharp and mobile interface separates injected water from ambient groundwater such that in situ mixing of water within and between strata does not occur. SASRM assigns particles to define the location the interface in all strata and then follows the migration of these particles under ambient and induced flow conditions. During water recovery, the transient location of the interface is simulated in each stratum and this information is used to quantify the fractions of ambient and injected water extracted at the well-head and the quality of water recovered. To mimic the effects of dispersion, a Latin Hypercube sampling strategy is used to assign hydraulic conductivities according to a predefined probability distribution to the layers of a conceptually stratified aquifer. The volumetric fraction of water received or delivered from any given lithologic unit is assumed proportional to the transmissivity of the stratum normalized to the total aquifer transmissivity interrogated by the ASR well. SARSM is numerically verified against MT3DMS and then calibrated and validated using field data from an ASR system located in Boynton Beach, FL. The field demonstration shows SASRM is capable of predicting

  16. MODFLOW-USG model of groundwater flow in the Wood River Valley aquifer system in Blaine County, Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A three-dimensional numerical groundwater flow model (MODFLOW-USG) was developed for the Wood River Valley (WRV) aquifer system, south-central Idaho, to evaluate...

  17. Geodatabase of the datasets used to represent the two subunits of the Central Valley aquifer system, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geodatabase includes spatial datasets that represent the Central Valley aquifer system in the State of California. Included are: (1) polygon extents; datasets...

  18. Identifying functional zones of denitrification in heterogeneous aquifer systems by numerical simulations - a case study

    Science.gov (United States)

    Jang, E.; Kalbacher, T.; He, W.; Shao, H.; Schueth, C.; Kolditz, O.

    2014-12-01

    Nitrate contamination in shallow groundwater is still one of the common problems in many countries. Because of its high solubility and anionic nature, nitrate can easily leach through soil and persist in groundwater for decades. High nitrate concentration has been suggested as a major cause of accelerated eutrophication, methemoglobinemia and gastric cancer. There are several factors influencing the fate of nitrate in groundwater system, which is e.g. distribution of N- sources to soil and groundwater, distribution and amount of reactive substances maintaining denitrification, rate of nitrate degradation and its kinetics, and geological characteristics of the aquifer. Nitrate transport and redox transformation processes are closely linked to complex and spatially distributed physical and chemical interaction, therefore it is difficult to predict and quantify in the field and laboratory experiment. Models can play a key role in elucidation of nitrate reduction pathway in groundwater system and in the design and evaluation of field tests to investigate in situ remediation technologies as well. The goal of the current study is to predict groundwater vulnerability to nitrate, to identify functional zones of denitrification in heterogeneous aquifer systems and to describe the uncertainty of the predictions due to scale effects. For this aim, we developed a kinetic model using multi-component mass transport code OpenGeoSys coupling with IPhreeqc module of the geochemical solver PHREEQC. The developed model included sequential aerobic and nitrate-based respiration, multi-Monod kinetics, multi-species biogeochemical reactions, and geological characteristics of the groundwater aquifer. Moreover water-rock interaction such as secondary mineral precipitation was also included in this model. In this presentation, we focused on the general modelling approach and present the simulation results of nitrate transport simulation in a hypothetical aquifer systems based on data from

  19. 3D geological modeling of the Kasserine Aquifer System, Central Tunisia: New insights into aquifer-geometry and interconnections for a better assessment of groundwater resources

    Science.gov (United States)

    Hassen, Imen; Gibson, Helen; Hamzaoui-Azaza, Fadoua; Negro, François; Rachid, Khanfir; Bouhlila, Rachida

    2016-08-01

    The challenge of this study was to create a 3D geological and structural model of the Kasserine Aquifer System (KAS) in central Tunisia and its natural extension into north-east Algeria. This was achieved using an implicit 3D method, which honors prior geological data for both formation boundaries and faults. A current model is presented which provides defendable predictions for the spatial distribution of geology and water resources in aquifers throughout the model-domain. This work has allowed validation of regional scale geology and fault networks in the KAS, and has facilitated the first-ever estimations of groundwater resources in this region by a 3D method. The model enables a preliminary assessment of the hydraulic significance of the major faults by evaluating their influence and role on groundwater flow within and between four compartments of the multi-layered, KAS hydrogeological system. Thus a representative hydrogeological model of the study area is constructed. The possible dual nature of faults in the KAS is discussed in the context that some faults appear to be acting both as barriers to horizontal groundwater flow, and simultaneously as conduits for vertical flow. Also discussed is the possibility that two flow directions occur within the KAS, at a small syncline area of near Feriana. In summary, this work evaluates the influence of aquifer connectivity and the role of faults and geology in groundwater flow within the KAS aquifer system. The current KAS geological model can now be used to guide groundwater managers on the best placement for drilling to test and further refine the understanding of the groundwater system, including the faults connectivity. As more geological data become available, the current model can be easily edited and re-computed to provide an updated model ready for the next stage of investigation by numerical flow modeling.

  20. Assessment of hydrochemical processes and groundwater hydrodynamics in a multilayer aquifer system under long-term irrigation condition: A case study of Nefzaoua basin, southern Tunisia.

    Science.gov (United States)

    Tarki, M; Ben Hammadi, M; El Mejri, H; Dassi, L

    2016-04-01

    The hydrochemical and isotopic investigation of the Nefzaoua aquifer system demonstrates that groundwater mineralization in is controlled by natural and anthropogenic processes including water-rock interaction and irrigation return flow. It identifies all of the water bodies that flow within the aquifer system and their circulation patterns. The isotopically depleted paleowaters, identified within the deep and intermediate aquifers, undergo significant enrichment by evaporation during irrigation and recharged the shallow aquifer by return flow. Subsequently, they infiltrate to the intermediate aquifer which receives also rainfall modern recharge.

  1. Groundwater quality in the Southeastern Coastal Plain aquifer system, southeastern United States

    Science.gov (United States)

    Barlow, Jeannie; Lindsey, Bruce; Belitz, Kenneth

    2017-01-19

    Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water. The Southeastern Coastal Plain aquifer system constitutes one of the important areas being evaluated. One or more inorganic constituents with human-health benchmarks were detected at high concentrations in about 6 percent of the study area and at moderate concentrations in about 13 percent. One or more organic constituents with human-health benchmarks were detected at moderate concentrations in about 3 percent of the study area.

  2. Groundwater quality in the Coastal Lowlands aquifer system, south-central United States

    Science.gov (United States)

    Barlow, Jeannie R.B.; Belitz, Kenneth

    2017-01-19

    Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water. The Coastal Lowlands aquifer system constitutes one of the important areas being evaluated. One or more inorganic constituents with human-health benchmarks were detected at high concentrations in about 12 percent of the study area and at moderate concentrations in about 18 percent. Organic constituents were not detected at high or moderate concentrations in the study area.

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

    Science.gov (United States)

    Garabedian, S.P.

    1992-01-01

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

  4. 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.

  5. Groundwater quality in the alluvial aquifer system of northwest India: New evidence of the extent of anthropogenic and geogenic contamination.

    Science.gov (United States)

    Lapworth, D J; Krishan, G; MacDonald, A M; Rao, M S

    2017-12-01

    Groundwater depletion has been widely studied in northwest India, but water quality concerns are still poorly constrained. In this study, we explore the hydrochemistry of the top 160m of the aquifer system, through detailed field studies in the Bist-Doab region, considering both anthropogenic and geogenic controls. A detailed comparison is made between sites dominated by urban and agricultural landuse. Salinity, nitrate, chloride and lead concentrations are significantly higher in the shallow (0-50m) groundwater system due to surface anthropogenic contaminant loading from agricultural and urban sources. The widespread occurrence of oxic groundwater within the aquifer system means that denitrification potential is limited and also enhances the mobility of selenium and uranium in groundwater. Geogenic trace elements (e.g. As, Se, F), are generally found at concentrations below WHO guideline drinking water values, however elevated U concentrations (50-70μg/L) are found within the deeper part of the aquifer and shallow urban aquifers associated with higher bicarbonate waters. Higher concentration of Se (10-40μg/L) are found exclusively in the shallow groundwater system where Se is mobilised from soils and transported to depth in the shallow aquifer due to the prevailing oxidising aquifer conditions. New evidence from a range of environmental tracers shows elevated concentrations of anthropogenic contaminants in the deeper part of the aquifer (50-160m deep) and demonstrates vulnerability to vertical migration of contaminants. Continued intensive groundwater abstraction from >100m deep means that water quality risks to the deep aquifer system need to be considered together with water quantity constraints. Copyright © 2017. Published by Elsevier B.V.

  6. Assessing electronic death registration and american red cross systems for mortality surveillance during Hurricane Sandy, October 29-November 10, 2012, New York City.

    Science.gov (United States)

    Howland, Renata E; Madsen, Ann M; Nicaj, Leze; Noe, Rebecca S; Casey-Lockyer, Mary; Begier, Elizabeth

    2014-12-01

    We briefly describe 2 systems that provided disaster-related mortality surveillance during and after Hurricane Sandy in New York City, namely, the New York City Health Department Electronic Death Registration System (EDRS) and the American Red Cross paper-based tracking system. Red Cross fatality data were linked with New York City EDRS records by using decedent name and date of birth. We analyzed cases identified by both systems for completeness and agreement across selected variables and the time interval between death and reporting in the system. Red Cross captured 93% (41/44) of all Sandy-related deaths; the completeness and quality varied by item, and timeliness was difficult to determine. The circumstances leading to death captured by Red Cross were particularly useful for identifying reasons individuals stayed in evacuation zones. EDRS variables were nearly 100% complete, and the median interval between date of death and reporting was 6 days (range: 0-43 days). Our findings indicate that a number of steps have the potential to improve disaster-related mortality surveillance, including updating Red Cross surveillance forms and electronic databases to enhance timeliness assessments, greater collaboration across agencies to share and use data for public health preparedness, and continued expansion of electronic death registration systems.

  7. Groundwater Flow Model of Göksu Delta Coastal Aquifer System

    Science.gov (United States)

    Erdem Dokuz, Uǧur; Çelik, Mehmet; Arslan, Şebnem; Engin, Hilal

    2016-04-01

    Like many other coastal areas, Göksu Delta (Mersin-Silifke, Southern Turkey) is a preferred place for human settlement especially due to its productive farmlands and water resources. The water dependent ecosystem in Göksu delta hosts about 332 different plant species and 328 different bird species besides serving for human use. Göksu Delta has been declared as Special Environmental Protection Zone, Wildlife Protection Area, and RAMSAR Convention for Wetlands of International Importance area. Unfortunately, rising population, agricultural and industrial activities cause degradation of water resources both by means of quality and quantity. This problem also exists for other wetlands around the world. It is necessary to prepare water management plans by taking global warming issues into account to protect water resources for next generations. To achieve this, the most efficient tool is to come up with groundwater management strategies by constructing groundwater flow models. By this aim, groundwater modeling studies were carried out for Göksu Delta coastal aquifer system. As a first and most important step in all groundwater modeling studies, geological and hydrogeological settings of the study area have been investigated. Göksu Delta, like many other deltaic environments, has a complex structure because it was formed with the sediments transported by Göksu River throughout the Quaternary period and shaped throughout the transgression-regression periods. Both due to this complex structure and the lack of observation wells penetrating deep enough to give an idea of the total thickness of the delta, it was impossible to reveal out the hydrogeological setting in a correct manner. Therefore, six wells were drilled to construct the conceptual hydrogeological model of Göksu Delta coastal aquifer system. On the basis of drilling studies and slug tests that were conducted along Göksu Delta, hydrostratigraphic units of the delta system have been obtained. According to

  8. Organic molecules as sorbing tracers for the assessment of surface areas in consolidated aquifer systems

    Science.gov (United States)

    Schaffer, Mario; Warner, Wiebke; Kutzner, Susann; Börnick, Hilmar; Worch, Eckhard; Licha, Tobias

    2017-03-01

    Based on the assumption that the specific surface area to volume ratio Asurf/V of consolidated rock materials is proportional to the surface area available for sorption, several inorganic cations were recently proposed as sorbing (cation exchanging) tracers for estimating these ratios in aquifers (e.g., for deriving the efficient heat exchange area of geothermal reservoirs). The main disadvantages of inorganic ions, however, are the limited number of suitable ions, their potential geogenic background, and their challenging online detection at trace concentrations. In this work, the spectrum of chemical substances used as sorbing tracers expands by considering fluorescent organic compounds that are cationic. They have the advantage of being highly water soluble and easy to measure online at very low concentrations. Results from systematic lab column experiments with seven selected organic cations under various conditions (different salinities and temperatures) are presented, emphasizing the potential of organic molecules as alternative sorbing tracers especially in consolidated aquifer systems. This work is a first stepping stone in identifying suitable molecular structures that can be selected or even individually adapted to the requirements of the tracer tests and prevailing aquifer conditions.

  9. Near-conservative behavior of 129Iodine in the Orange County Aquifer System, California

    Energy Technology Data Exchange (ETDEWEB)

    Schwer, K A; Santschi, P H; Moran, J E; Elmore, D

    2005-01-21

    Iodine is a biophilic element, with one stable isotope, {sup 127}I, and one long-lived radioisotope, {sup 129}I, which originates in the surface environment almost entirely from anthropogenic activities such as nuclear fuel reprocessing. Very few studies have evaluated the geochemical behavior of iodine isotopes in the subsurface. The concentrations of {sup 129}I and {sup 127}I were measured in wells fed by a series of artificial recharge ponds in the Forebay Area of the Orange County groundwater basin (California, USA) to evaluate their potential use as hydrological tracers. To substantiate interpretation of {sup 129}I and {sup 127}I concentration data, the aquifer system was evaluated using literature values of aquifer water mass age based on {sup 3}H/{sup 3}He, Xenon and {delta}{sup 18}O tracer data, as well as time-series data of Santa Ana River flow rates over the past decade. The aquifer data demonstrate the nearly conservative behavior of {sup 129}I, with {sup 129}I/{sup 127}I ratios likely reflecting variations in source functions as well as climatic conditions, and with inferred particle-water partition coefficients (K{sub d}) of 0.1 cm{sup 3} g{sup -1} or less.

  10. Flow and Transport in the Hanford 300 Area Vadose Zone-Aquifer-River System

    Energy Technology Data Exchange (ETDEWEB)

    Waichler, Scott R.; Yabusaki, Steven B.

    2005-07-13

    Contaminant migration in the 300 Area unconfined aquifer is strongly coupled to fluctuations in the Columbia River stage. To better understand the interaction between the river, aquifer, and vadose zone, a 2-D saturated-unsaturated flow and transport model was developed for a vertical cross-section aligned west-east across the Hanford Site 300 Area, nearly perpendicular to the river. The model was used to investigate water flow and tracer transport in the vadose zone-aquifer-river flow system, in support of the ongoing study of the 300 Area uranium plume. The STOMP simulator was used to model 1-year from 3/1/92 to 2/28/93, a period when hourly data were available for both groundwater and river levels. Net water flow to the river (per 1-meter width of shoreline) was 182 m3/y in the base case, but the cumulative exchange or total flow back and forth across the riverbed was 30 times greater. The low river case had approximately double the net water and Groundwater tracer flux into the river as compared to the base case.

  11. Saltwater intrusion in the Floridan aquifer system near downtown Brunswick, Georgia, 1957–2015

    Science.gov (United States)

    Cherry, Gregory S.; Peck, Michael

    2017-02-16

    IntroductionThe Floridan aquifer system (FAS) consists of the Upper Floridan aquifer (UFA), an intervening confining unit of highly variable properties, and the Lower Floridan aquifer (LFA). The UFA and LFA are primarily composed of Paleocene- to Oligocene-age carbonate rocks that include, locally, Upper Cretaceous rocks. The FAS extends from coastal areas in southeastern South Carolina and continues southward and westward across the coastal plain of Georgia and Alabama, and underlies all of Florida. The thickness of the FAS varies from less than 100 feet (ft) in aquifer outcrop areas of South Carolina to about 1,700 ft near the city of Brunswick, Georgia.Locally, in southeastern Georgia and the Brunswick– Glynn County area, the UFA consists of an upper water-bearing zone (UWBZ) and a lower water-bearing zone (LWBZ), as identified by Wait and Gregg (1973), with aquifer test data indicating the upper zone has higher productivity than the lower zone. Near the city of Brunswick, the LFA is composed of two permeable zones: an early middle Eocene-age upper permeable zone (UPZ) and a highly permeable lower zone of limestone (LPZ) of Paleocene and Late Cretaceous age that includes a deeply buried, cavernous, saline water-bearing unit known as the Fernandina permeable zone. Maslia and Prowell (1990) inferred the presence of major northeast–southwest trending faults through the downtown Brunswick area based on structural analysis of geophysical data, northeastward elongation of the potentiometric surface of the UFA, and breaches in the local confining unit that influence the area of chloride contamination. Pronounced horizontal and vertical hydraulic head gradients, caused by pumping in the UFA, allow saline water from the FPZ to migrate upward into the UFA through this system of faults and conduits.Saltwater was first detected in the FAS in wells completed in the UFA near the southern part of the city of Brunswick in late 1957. By the 1970s, a plume of groundwater

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

    Science.gov (United States)

    Bartolino, James R.; Adkins, Candice B.

    2012-01-01

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

  13. The fluoride in the groundwater of Guarani Aquifer System: the origin associated with black shales of Paraná Basin

    Science.gov (United States)

    Kern, M. L.; Vieiro, A. P.; Machado, G.

    2008-09-01

    This work presents petrological and geochemical results of the black shales interval from Permian and Devonian strata of the Paraná Basin, Brazil and its relationships with fluoride of groundwater from Guarani Aquifer System. The Guarani Aquifer, located in South Brazil, Uruguay, Paraguay and Argentine, presents contents of fluoride higher than the Brazilian accepted potability limits. Several hypotheses have been presented for the origin of the fluoride in the groundwater of the Guarani Aquifer. Microcrystalline fluorite was registered in black shales of Ponta Grossa and Irati formations from Paraná Basin. The results shown in this work suggest that fluoride present in groundwater of Guarani Aquifer can be originated in deeper groundwater that circulates in Ponta Grossa and Irati formations. The interaction of the groundwater coming from deeper black shales with the groundwater-bearing Aquifer Guarani System occurs through regional fragile structures (faults and fractures) that constitute excellent hydraulic connectors between the two sedimentary packages. The microcrystalline fluorite registered in Ponta Grossa and Irati Formations can be dissolved promoting fluoride enrichment in groundwater of these black shales and Guarani Aquifer System.

  14. Numerical simulation of groundwater flow in the Columbia Plateau Regional Aquifer System, Idaho, Oregon, and Washington

    Science.gov (United States)

    Ely, D. Matthew; Burns, Erick R.; Morgan, David S.; Vaccaro, John J.

    2014-01-01

    A three-dimensional numerical model of groundwater flow was constructed for the Columbia Plateau Regional Aquifer System (CPRAS), Idaho, Oregon, and Washington, to evaluate and test the conceptual model of the system and to evaluate groundwater availability. The model described in this report can be used as a tool by water-resource managers and other stakeholders to quantitatively evaluate proposed alternative management strategies and assess the long‑term availability of groundwater. The numerical simulation of groundwater flow in the CPRAS was completed with support from the Groundwater Resources Program of the U.S. Geological Survey Office of Groundwater.

  15. Hydrogeochemical modelling of geothermal systems in the Malm Aquifer

    Science.gov (United States)

    Baumann, Thomas; Ueckert, Martina

    2017-04-01

    The Malm sediments in the Bavarian Molasse Basin are very suitable for hydrogeothermal heat and energy production and for energy storage. With the conversion of the Pullach injection well to a production well it was possible to quantify the reactions in the reservoir and to validate the hydrogeochemical models. This data set was complemented by the results from a heat storage test. The calibrated hydrogeochemical model was used to predict and optimize the long term behaviour of geothermal doublets. In facilities using more than two wells, mixing ratios for the production wells were assessed and optimized. Most of the simulations showed a benign long-term behaviour, even in more complex systems. Dissolution of carbonates at the injection wells propagates into the reservoir and contributes to an increase of the injectivity. It also seems to be possible to make use of the gas load which is otherwise crucial to maintain to prevent the formation of scalings. The situation changes for geothermal heat storage systems, eg. a geothermal doublet in combination with a combined heat and power plant. The cyclic operation causes a significant increase of the carbonate concentrations. Consequently, the amount of eg. CO2 that has to be added to the water to prevent precipitation of carbonates during the heating cycle, has to increase as well. The simulation results show that a doublet system for heat storage reaches an unstable situation after a few cycles. These results are supported by the data form a heat storage test and by the data from the conversion of the Pullach well. The model also shows that long-term operation is possible in a triplet setup.

  16. Field Study to Assess the Effects of Trace Concentrations of the Common Antibiotic Sulfamethoxazole on the Attached Bacterial Community Inhabiting a Sandy, Drinking-Water Aquifer in Cape Cod, Massachusetts USA.

    Science.gov (United States)

    Harvey, R. W.; Underwood, J. C.; Metge, D. W.; Barber, L. B.; LeBlanc, D. R.

    2016-12-01

    Subtherapeutic levels of a commonly used antibiotic, sulfamethoxazole (SMx), has been detected in a variety of drinking-water aquifers. Recent microcosm studies suggest that very low concentrations of SMx, which is highly mobile and persistent in subsurface environments, can suppress nitrate reduction and growth of unattached groundwater bacteria. However, most aquifer bacteria are associated with mineral surfaces and it remains unclear to what extent attached microbial communities are impacted by SMx and whether any such impairment(s) are ameliorated by the presence of nutrients from the same contaminant source. The present 30-day in-situ dosing study assessed the inhibitory effects of low SMx concentrations upon sediment-attached aquifer bacteria in the presence and absence of nutrient amendments. Bacterial responses were compared for exposure to: 1) SMx alone ( 400 ppb), 2) SMx and nutrients ( 0.2 mM acetate, 0.1 mM NaNO3 and 0.1 mM NH4Cl), 3) nutrients alone, and 4) ambient groundwater. The field test used an array of 8 pairs of 5-cm (diameter) PVC injection and observation wells with slotted screens placed 9.6-10.2 m below land surface (˜5 m below water table). Aquifer sediments containing microbial communities were placed inside filter chambers that were positioned within the screened sections of the observation wells arranged in a row perpendicular to the direction of groundwater flow. Bromide (0.7 mM) was used as a conservative tracer. Evidence that SMx suppresses in-situ reduction of nitrate to nitrite was apparent from the substantial lag (9.5 days) in breakthrough of the nitrite within the wells exposed to SMx and nutrients as compared to nutrients alone. Acetate consumption data indicated that the presence of SMx could affect degradation of other organic contaminants in groundwater, although the inhibitory effects may be ameliorated, in part, by the presence of nutrients that are co-transported within a wastewater plume.

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

    Science.gov (United States)

    Denver, Judith; Nardi, Mark R.

    2017-01-01

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

  18. 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

  19. Summary and evaluation of hydraulic property data available for the Hanford Site upper basalt confined aquifer system

    Energy Technology Data Exchange (ETDEWEB)

    Spane, F.A. Jr.; Vermeul, V.R.

    1994-09-01

    Pacific Northwest Laboratory, as part of the Hanford Site Ground-Water Surveillance Project, examines the potential for offsite migration of contamination within the upper basalt confined aquifer system. For the past 40 years, hydrologic testing of the upper basalt confined aquifer has been conducted by a number of Hanford Site programs. Hydraulic property estimates are important for evaluating aquifer flow characteristics (i.e., ground-water flow patterns, flow velocity, transport travel time). Presented are the first comprehensive Hanford Site-wide summary of hydraulic properties for the upper basalt confined aquifer system (i.e., the upper Saddle Mountains Basalt). Available hydrologic test data were reevaluated using recently developed diagnostic test analysis methods. A comparison of calculated transmissivity estimates indicates that, for most test results, a general correspondence within a factor of two between reanalysis and previously reported test values was obtained. For a majority of the tests, previously reported values are greater than reanalysis estimates. This overestimation is attributed to a number of factors, including, in many cases, a misapplication of nonleaky confined aquifer analysis methods in previous analysis reports to tests that exhibit leaky confined aquifer response behavior. Results of the test analyses indicate a similar range for transmissivity values for the various hydro-geologic units making up the upper basalt confined aquifer. Approximately 90% of the calculated transmissivity values for upper basalt confined aquifer hydrogeologic units occur within the range of 10{sup 0} to 10{sup 2} m{sup 2}/d, with 65% of the calculated estimate values occurring between 10{sup 1} to 10{sup 2} m{sup 2}d. These summary findings are consistent with the general range of values previously reported for basalt interflow contact zones and sedimentary interbeds within the Saddle Mountains Basalt.

  20. Water Control Study for Extra-thick Coal Seam Fully Mechanized Caving Mining under Thick Sandy Conglomerate Aquifer%厚砂砾含水层下特厚煤层综放开采防治水技术研究

    Institute of Scientific and Technical Information of China (English)

    刘英锋

    2011-01-01

    水帘洞煤矿地表水系发育,煤系地层上覆的白平系洛河组和宜君组巨厚层状砂砾岩含水层,含水丰富,对矿井的安全开采构成了威胁.在详细分析矿区顶板含水层特征、隔水层岩性组合特征及隔水性能基础上.采用比拟法计算了综放条件下顶板导水裂隙带发育高度,并用数值法研究了不同采宽条件下顶板导水裂缝带发育规律,预计了工作面涌水量,为评价煤矿综放条件下工作面安全回采可行性提供了科学的依据.%Surface drainage is rather developed in the Shuiliandong coalmine area, coal measures strata overlying Cretaceous Luohe and Yijun formations extra-thick layered sandy conglomerate aquifer contains abundant water and threatens safe working of coalmines.Based on detailed analysis of roof aquifer characteristics, aquffuge lithologie association characteristics and water confining performance, using analogue method estimated height of roof water conducted zone under fully mechanized caving condition, and using numerical method studied roof conducted zone development pattern under different shear width conditions, and predicted working face mine inflow.Thus the study has provided scientific basis for working face safe winning feasibility under coalmine fully mechanized caving condition.

  1. Ground-water hydraulics, regional flow, and ground-water development of the Floridan aquifer system in Florida and in parts of Georgia, South Carolina, and Alabama

    Science.gov (United States)

    Bush, Peter W.; Johnston, Richard H.

    1988-01-01

    The Floridan aquifer system is one of the major sources of groundwater supplies in the United States. This productive aquifer system underlies all of Florida, southeast Georgia, and small parts of adjoining Alabama and South Carolina, for a total area of about 100,000 square miles. About 3 billion gallons of water per day were withdrawn from the aquifer system in 1980, and in many areas the Floridan is the sole source of freshwater.

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

    Science.gov (United States)

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

    2009-05-01

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

  3. Performance evaluation of a reverse-gradient artificial recharge system in basalt aquifers of Maharashtra, India

    Science.gov (United States)

    Bhusari, Vijay; Katpatal, Y. B.; Kundal, Pradeep

    2016-12-01

    Drinking water scarcity in rural parts of central India in basaltic terrain is common. Most of the rural population depends on groundwater sources located in the fractured and weathered zone of the basaltic aquifers. Long-term indiscriminate withdrawal has caused an alarming rate of depletion of groundwater levels in both pre- and post-monsoon periods. The aquifer is not replenished through precipitation under natural conditions. To overcome this situation, an innovative artificial recharge system, called the reverse-gradient recharge system (RGRS), was implemented in seven villages of Wardha district of Maharashtra. The study described here presents a comparative analysis of recharge systems constructed in the year 2012 downstream of dug-well locations in these seven villages. The post-project comparative analysis reveals that the area of influence (AOI) of the groundwater recharge system, within which increases in groundwater levels and yield are observed, is directly related to the specific yield, thickness of the weathered and fractured zone, porosity, and transmissivity of the aquifer, showing high correlation coefficients of 0.92, 0.88, 0.85 and 0.83, respectively. The study indicates that the RGRS is most effective in vesicular weathered and fractured basalt, recording a maximum increase in well yield of 65-82 m3/day, while a minimum increase in yield of 15-30 m3/day was observed in weathered vesicular basalt. The comparative analysis thus identifies the controlling factors which facilitate groundwater recharge through the proposed RGRS. After implementation of these projects, the groundwater availability in these villages increased significantly, solving their drinking water problems.

  4. Performance evaluation of a reverse-gradient artificial recharge system in basalt aquifers of Maharashtra, India

    Science.gov (United States)

    Bhusari, Vijay; Katpatal, Y. B.; Kundal, Pradeep

    2017-05-01

    Drinking water scarcity in rural parts of central India in basaltic terrain is common. Most of the rural population depends on groundwater sources located in the fractured and weathered zone of the basaltic aquifers. Long-term indiscriminate withdrawal has caused an alarming rate of depletion of groundwater levels in both pre- and post-monsoon periods. The aquifer is not replenished through precipitation under natural conditions. To overcome this situation, an innovative artificial recharge system, called the reverse-gradient recharge system (RGRS), was implemented in seven villages of Wardha district of Maharashtra. The study described here presents a comparative analysis of recharge systems constructed in the year 2012 downstream of dug-well locations in these seven villages. The post-project comparative analysis reveals that the area of influence (AOI) of the groundwater recharge system, within which increases in groundwater levels and yield are observed, is directly related to the specific yield, thickness of the weathered and fractured zone, porosity, and transmissivity of the aquifer, showing high correlation coefficients of 0.92, 0.88, 0.85 and 0.83, respectively. The study indicates that the RGRS is most effective in vesicular weathered and fractured basalt, recording a maximum increase in well yield of 65-82 m3/day, while a minimum increase in yield of 15-30 m3/day was observed in weathered vesicular basalt. The comparative analysis thus identifies the controlling factors which facilitate groundwater recharge through the proposed RGRS. After implementation of these projects, the groundwater availability in these villages increased significantly, solving their drinking water problems.

  5. Determination of dominant biogeochemical processes in a contaminated aquifer-wetland system using multivariate statistical analysis

    Science.gov (United States)

    Baez-Cazull, S. E.; McGuire, J.T.; Cozzarelli, I.M.; Voytek, M.A.

    2008-01-01

    Determining the processes governing aqueous biogeochemistry in a wetland hydrologically linked to an underlying contaminated aquifer is challenging due to the complex exchange between the systems and their distinct responses to changes in precipitation, recharge, and biological activities. To evaluate temporal and spatial processes in the wetland-aquifer system, water samples were collected using cm-scale multichambered passive diffusion samplers (peepers) to span the wetland-aquifer interface over a period of 3 yr. Samples were analyzed for major cations and anions, methane, and a suite of organic acids resulting in a large dataset of over 8000 points, which was evaluated using multivariate statistics. Principal component analysis (PCA) was chosen with the purpose of exploring the sources of variation in the dataset to expose related variables and provide insight into the biogeochemical processes that control the water chemistry of the system. Factor scores computed from PCA were mapped by date and depth. Patterns observed suggest that (i) fermentation is the process controlling the greatest variability in the dataset and it peaks in May; (ii) iron and sulfate reduction were the dominant terminal electron-accepting processes in the system and were associated with fermentation but had more complex seasonal variability than fermentation; (iii) methanogenesis was also important and associated with bacterial utilization of minerals as a source of electron acceptors (e.g., barite BaSO4); and (iv) seasonal hydrological patterns (wet and dry periods) control the availability of electron acceptors through the reoxidation of reduced iron-sulfur species enhancing iron and sulfate reduction. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  6. Transport modeling and multivariate adaptive regression splines for evaluating performance of ASR systems in freshwater aquifers

    Science.gov (United States)

    Forghani, Ali; Peralta, Richard C.

    2017-10-01

    The study presents a procedure using solute transport and statistical models to evaluate the performance of aquifer storage and recovery (ASR) systems designed to earn additional water rights in freshwater aquifers. The recovery effectiveness (REN) index quantifies the performance of these ASR systems. REN is the proportion of the injected water that the same ASR well can recapture during subsequent extraction periods. To estimate REN for individual ASR wells, the presented procedure uses finely discretized groundwater flow and contaminant transport modeling. Then, the procedure uses multivariate adaptive regression splines (MARS) analysis to identify the significant variables affecting REN, and to identify the most recovery-effective wells. Achieving REN values close to 100% is the desire of the studied 14-well ASR system operator. This recovery is feasible for most of the ASR wells by extracting three times the injectate volume during the same year as injection. Most of the wells would achieve RENs below 75% if extracting merely the same volume as they injected. In other words, recovering almost all the same water molecules that are injected requires having a pre-existing water right to extract groundwater annually. MARS shows that REN most significantly correlates with groundwater flow velocity, or hydraulic conductivity and hydraulic gradient. MARS results also demonstrate that maximizing REN requires utilizing the wells located in areas with background Darcian groundwater velocities less than 0.03 m/d. The study also highlights the superiority of MARS over regular multiple linear regressions to identify the wells that can provide the maximum REN. This is the first reported application of MARS for evaluating performance of an ASR system in fresh water aquifers.

  7. Simulation of groundwater flow in the glacial aquifer system of northeastern Wisconsin with variable model complexity

    Science.gov (United States)

    Juckem, Paul F.; Clark, Brian R.; Feinstein, Daniel T.

    2017-05-04

    The U.S. Geological Survey, National Water-Quality Assessment seeks to map estimated intrinsic susceptibility of the glacial aquifer system of the conterminous United States. Improved understanding of the hydrogeologic characteristics that explain spatial patterns of intrinsic susceptibility, commonly inferred from estimates of groundwater age distributions, is sought so that methods used for the estimation process are properly equipped. An important step beyond identifying relevant hydrogeologic datasets, such as glacial geology maps, is to evaluate how incorporation of these resources into process-based models using differing levels of detail could affect resulting simulations of groundwater age distributions and, thus, estimates of intrinsic susceptibility.This report describes the construction and calibration of three groundwater-flow models of northeastern Wisconsin that were developed with differing levels of complexity to provide a framework for subsequent evaluations of the effects of process-based model complexity on estimations of groundwater age distributions for withdrawal wells and streams. Preliminary assessments, which focused on the effects of model complexity on simulated water levels and base flows in the glacial aquifer system, illustrate that simulation of vertical gradients using multiple model layers improves simulated heads more in low-permeability units than in high-permeability units. Moreover, simulation of heterogeneous hydraulic conductivity fields in coarse-grained and some fine-grained glacial materials produced a larger improvement in simulated water levels in the glacial aquifer system compared with simulation of uniform hydraulic conductivity within zones. The relation between base flows and model complexity was less clear; however, the relation generally seemed to follow a similar pattern as water levels. Although increased model complexity resulted in improved calibrations, future application of the models using simulated particle

  8. Subsidence Modeling of the Over-exploited Granular Aquifer System in Aguascalientes, Mexico

    Science.gov (United States)

    Solano Rojas, D. E.; Wdowinski, S.; Minderhoud, P. P. S.; Pacheco, J.; Cabral, E.

    2016-12-01

    The valley of Aguascalientes in central Mexico experiences subsidence rates of up to 100 [mm/yr] due to overexploitation of its aquifer system, as revealed from satellite-based geodetic observations. The spatial pattern of the subsidence over the valley is inhomogeneous and affected by shallow faulting. The understanding of the subsoil mechanics is still limited. A better understanding of the subsidence process in Aguascalientes is needed to provide insights for future subsidence in the valley. We present here a displacement-constrained finite-element subsidence model using Deltares iMOD (interactive MODeling), based on the USGS MODFLOW software. The construction of our model relies on 3 main inputs: (1) groundwater level time series obtained from extraction wells' hydrographs, (2) subsurface lithostratigraphy interpreted from well drilling logs, and (3) hydrogeological parameters obtained from field pumping tests. The groundwater level measurements were converted to pore pressure in our model's layers, and used in Terzaghi's equation for calculating effective stress. We then used the effective stresse along with the displacement obtained from geodetic observations to constrain and optimize five geo-mechanical parameters: compression ratio, reloading ratio, secondary compression index, over consolidation ratio, and consolidation coefficient. Finally, we use the NEN-Bjerrum linear stress model formulation for settlements to determine elastic and visco-plastic strain, accounting for the aquifer system units' aging effect. Preliminary results show higher compaction response in clay-saturated intervals (i.e. aquitards) of the aquifer system, as reflected in the spatial pattern of the surface deformation. The forecasted subsidence for our proposed scenarios show a much more pronounced deformation when we consider higher groundwater extraction regimes.

  9. 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

    Executive SummaryThe U.S. Geological Survey began a multiyear regional assessment of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system in 2010 as part of its ongoing regional assessments of groundwater availability of the principal aquifers of the Nation. The goals of this national assessment are to document effects of human activities on water levels and groundwater storage, explore climate variability effects on the regional water budget, and provide consistent and integrated information that is useful to those who use and manage the groundwater resource. As part of this nationwide assessment, the USGS evaluated available groundwater resources within the NACP aquifer system from Long Island, New York, to northeastern North Carolina.The northern Atlantic Coastal Plain physiographic province depends heavily on groundwater to meet agricultural, industrial, and municipal needs. The groundwater assessment of the NACP aquifer system included an evaluation of how water use has changed over time; this evaluation primarily used groundwater budgets and development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends.This assessment focused on multiple spatial and temporal scales to examine changes in groundwater pumping, storage, and water levels. The regional scale provides a broad view of the sources and demands on the system with time. The sub-regional scale provides an evaluation of the differing response of the aquifer system across geographic areas allowing for closer examination of the interaction between different aquifers and confining units and the changes in these interactions under pumping and recharge conditions in 2013 and hydrologic stresses as much as 45 years in the future. By focusing on multiple scales, water-resource managers may utilize this study to understand system response to changes as they affect the system as a whole.The NACP aquifer system extends from

  10. Response of intertidal sandy-beach macrofauna to human trampling: An urban vs. natural beach system approach.

    Science.gov (United States)

    Reyes-Martínez, Ma José; Ruíz-Delgado, Ma Carmen; Sánchez-Moyano, Juan Emilio; García-García, Francisco José

    2015-02-01

    Sandy beaches are subjected to intense stressors, which are mainly derived from the increasing pattern of beach urbanization. These ecosystems are also a magnet for tourists, who prefer these locations as leisure and holiday destinations, and such activity further increases the factors that have an adverse effect on beaches. In the study reported here the effect of human trampling on macrofauna assemblages that inhabit intertidal areas of sandy beaches was assessed using a BACI design. For this purpose, three contrasting sectors of the same beach were investigated: an urban area with a high level of visitors, a protected sector with a low density of users, and a transitional area with a high level of human occupancy. The physical variables were constant over time in each sector, whereas differences were found in the intensity of human use between sectors. Density variations and changes in the taxonomic structure of the macrofauna with time were shown by PERMANOVA analysis in the urban and transitional locations whereas the protected sector remained constant throughout the study period. The amphipod Bathyporeia pelagica appears sensitive to human trampling pressure and the use of this species as a bioindicator for these types of impact is recommended. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Different spatial discretization methods of fault systems on heat transport processes in hard rock aquifers

    Science.gov (United States)

    Kruppa, Lisa; König, Christoph M.; Becker, Martin; Seidel, Torsten

    2016-04-01

    Most hard rock aquifers, which are important for geothermal use, contain fractures of different type and scale. These fault systems are of major significance for heat flow in the groundwater. The hydrogeological characterization of fault systems must therefore be part of any site investigation in hard rock aquifers and hydraulically important fault systems need to be appropriately represented in associated numerical models. This contribution discusses different spatial discretization methods of fault systems in three-dimensional groundwater models and their impact on the simulated groundwater flow field as well as density and viscosity dependent heat transport. The analysis includes a comparison of the convergence behavior and numerical stability of the different discretization methods. To ensure defendable results, the utilized numerical model SPRING was first verified against data from the Hydrocoin Level 1 Case 2 project. After verification, the software was used to evaluate the impact of different discretization strategies on steady-state and transient groundwater flow and transport model results. The results show a significant influence of the spatial discretization strategy on predicted flow rates and subsequent mass fluxes as well as energy balances.

  12. Potential effects of deepening the St. Johns River navigation channel on saltwater intrusion in the surficial aquifer system, Jacksonville, Florida

    Science.gov (United States)

    Bellino, Jason C.; Spechler, Rick M.

    2013-01-01

    The U.S. Army Corps of Engineers (USACE) has proposed dredging a 13-mile reach of the St. Johns River navigation channel in Jacksonville, Florida, deepening it to depths between 50 and 54 feet below North American Vertical Datum of 1988. The dredging operation will remove about 10 feet of sediments from the surficial aquifer system, including limestone in some locations. The limestone unit, which is in the lowermost part of the surficial aquifer system, supplies water to domestic wells in the Jacksonville area. Because of density-driven hydrodynamics of the St. Johns River, saline water from the Atlantic Ocean travels upstream as a saltwater “wedge” along the bottom of the channel, where the limestone is most likely to be exposed by the proposed dredging. A study was conducted to determine the potential effects of navigation channel deepening in the St. Johns River on salinity in the adjacent surficial aquifer system. Simulations were performed with each of four cross-sectional, variable-density groundwater-flow models, developed using SEAWAT, to simulate hypothetical changes in salinity in the surficial aquifer system as a result of dredging. The cross-sectional models were designed to incorporate a range of hydrogeologic conceptualizations to estimate the effect of uncertainty in hydrogeologic properties. The cross-sectional models developed in this study do not necessarily simulate actual projected conditions; instead, the models were used to examine the potential effects of deepening the navigation channel on saltwater intrusion in the surficial aquifer system under a range of plausible hypothetical conditions. Simulated results for modeled conditions indicate that dredging will have little to no effect on salinity variations in areas upstream of currently proposed dredging activities. Results also indicate little to no effect in any part of the surficial aquifer system along the cross section near River Mile 11 or in the water-table unit along the cross

  13. GRACE-Based Analysis of Total Water Storage Trends and Groundwater Fluctuations in the North-Western Sahara Aquifer System (NWSAS) and Tindouf Aquifer in Northwest Africa

    Science.gov (United States)

    Lezzaik, K. A.; Milewski, A.

    2013-12-01

    Optimal water management practices and strategies, in arid and semi-arid environments, are often hindered by a lack of quantitative and qualitative understanding of hydrological processes. Moreover, progressive overexploitation of groundwater resources to meet agricultural, industrial, and domestic requirements is drawing concern over the sustainability of such exhaustive abstraction levels, especially in environments where groundwater is a major source of water. NASA's GRACE (gravity recovery and climate change experiment) mission, since March 2002, has advanced the understanding of hydrological events, especially groundwater depletion, through integrated measurements and modeling of terrestrial water mass. In this study, GLDAS variables (rainfall rate, evapotranspiration rate, average soil moisture), and TRMM 3B42.V7A precipitation satellite data, were used in combination with 95 GRACE-generated gravitational anomalies maps, to quantify total water storage change (TWSC) and groundwater storage change (GWSC) from January 2003 to December 2010 (excluding June 2003), in the North-Western Sahara Aquifer System (NWSAS) and Tindouf Aquifer System in northwestern Africa. Separately processed and computed GRACE products by JPL (Jet Propulsion Laboratory, NASA), CSR (Center of Space Research, UT Austin), and GFZ (German Research Centre for Geoscience, Potsdam), were used to determine which GRACE dataset(s) best reflect total water storage and ground water changes in northwest Africa. First-order estimates of annual TWSC for NWSAS (JPL: +5.297 BCM; CSR: -5.33 BCM; GFZ: -9.96 BCM) and Tindouf Aquifer System (JPL: +1.217 BCM; CSR: +0.203 BCM; GFZ: +1.019 BCM), were computed using zonal averaging over a span of eight years. Preliminary findings of annual GWSC for NWSAS (JPL: +2.45 BCM; CSR: -2.278 BCM; GFZ: -6.913 BCM) and Tindouf Aquifer System (JPL: +1.108 BCM; CSR: +0.094 BCM; GFZ: +0.910 BCM), were calculating using a water budget approach, parameterized by GLDAS

  14. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface for transmissivity of the Upper Floridan aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  15. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions depicting the low-permeability units that overlie the Lower Floridan aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  16. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the top of the Lower Floridan aquifer below the LISAPCU, constrained

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  17. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Area where upper confining unit is thin or absent beneath the surficial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  18. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for the top of the Lower Floridan aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  19. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting top of the Lower Floridan aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  20. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the top of the Lower Floridan aquifer below the LISAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  1. Natural radionuclides in major aquifer systems of the Parana sedimentary basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Bonotto, Daniel Marcos, E-mail: danielbonotto@yahoo.com.br [Departamento de Petrologia e Metalogenia, IGCE-Instituto de Geociencias e Ciencias Exatas, UNESP-Universidade Estadual Paulista Julio de Mesquita Filho, Av. 24-A, No. 1515 - CP 178, CEP 13506-900-Rio Claro, SP (Brazil)

    2011-10-15

    This paper describes the natural radioactivity of groundwater occurring in sedimentary (Bauru and Guarani) and fractured rock (Serra Geral) aquifer systems in the Parana sedimentary basin, South America that is extensively used for drinking purposes, among others. The measurements of gross alpha and gross beta radioactivity as well the activity concentration of the natural dissolved radionuclides {sup 40}K, {sup 238}U, {sup 234}U, {sup 226}Ra, {sup 222}Rn, {sup 210}Po and {sup 210}Pb were held in 80 tubular wells drilled in 21 municipalities located at Sao Paulo State and its border with Mato Grosso do Sul State in Brazil. Most of the gross alpha radioactivity data were below 1 mBq/L, whereas values exceeding the gross beta radioactivity detection limit of 30 mBq/L were found. The radioelement solubility in the studied systems varied according to the sequence radon>radium>other radionuclides and the higher porosity of sandstones relatively to basalts and diabases could justify the enhanced presence of dissolved radon in the porous aquifer. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed. The population-weighted average activity concentration for these radionuclides was compared to the guideline value of 0.1 mSv/yr for the total effective dose and discussed in terms of the choice of the dose conversion factors. - Highlights: > Integration of distinct radiometric data acquired in groundwaters. > Radiation dose in important hydrological resources in South America. > Contribution of {sup 226}Ra for the more accentuated radiation dose in aquifers. > Dose factors for Rn and generation of values exceeding the maximum of 0.1 mSv/yr.

  2. Morphological records of storm floods exemplified by the impact of the 1872 Baltic storm on a sandy spit system in south-eastern Denmark

    DEFF Research Database (Denmark)

    Clemmensen, Lars B; Bendixen, Mette; Hede, Mikkel Ulfeldt

    2014-01-01

    Beach-ridge systems are important geo-archives providing evidence for past wave climate including catastrophic storm flood events. This study investigates the morphological impacts of the 1872 Baltic storm flood on a beach-ridge system (sandy spit) in south-eastern Denmark and evaluates...... the dune ridge at several sites and wash-over fans were generated until a level where the mean water level had dropped too much. Phase 4: the non-vegetated wash-over fans functioned as pathways for aeolian sand transport and relatively high dunes were formed in particular along the margins of the fan where...... aeolian sand was trapped by existing vegetation. The studied beach-ridge system records about 4500 years of accumulation; the storm flood sediments described are unique suggesting that the 1872 Baltic storm flood event was an extreme event. Thus studies of beach-ridge systems form a new source...

  3. 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

    Executive SummaryThe U.S. Geological Survey began a multiyear regional assessment of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system in 2010 as part of its ongoing regional assessments of groundwater availability of the principal aquifers of the Nation. The goals of this national assessment are to document effects of human activities on water levels and groundwater storage, explore climate variability effects on the regional water budget, and provide consistent and integrated information that is useful to those who use and manage the groundwater resource. As part of this nationwide assessment, the USGS evaluated available groundwater resources within the NACP aquifer system from Long Island, New York, to northeastern North Carolina.The northern Atlantic Coastal Plain physiographic province depends heavily on groundwater to meet agricultural, industrial, and municipal needs. The groundwater assessment of the NACP aquifer system included an evaluation of how water use has changed over time; this evaluation primarily used groundwater budgets and development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends.This assessment focused on multiple spatial and temporal scales to examine changes in groundwater pumping, storage, and water levels. The regional scale provides a broad view of the sources and demands on the system with time. The sub-regional scale provides an evaluation of the differing response of the aquifer system across geographic areas allowing for closer examination of the interaction between different aquifers and confining units and the changes in these interactions under pumping and recharge conditions in 2013 and hydrologic stresses as much as 45 years in the future. By focusing on multiple scales, water-resource managers may utilize this study to understand system response to changes as they affect the system as a whole.The NACP aquifer system extends from

  4. Hydrogeology and simulation of groundwater flow and land-surface subsidence in the northern part of the Gulf Coast aquifer system, Texas, 1891-2009

    Science.gov (United States)

    Kasmarek, Mark C.

    2012-01-01

    In cooperation with the Harris–Galveston Subsidence District, Fort Bend Subsidence District, and Lone Star Groundwater Conservation District, the U.S. Geological Survey developed and calibrated the Houston Area Groundwater Model (HAGM), which simulates groundwater flow and land-surface subsidence in the northern part of the Gulf Coast aquifer system in Texas from predevelopment (before 1891) through 2009. Withdrawal of groundwater since development of the aquifer system has resulted in potentiometric surface (hydraulic head, or head) declines in the Gulf Coast aquifer system and land-surface subsidence (primarily in the Houston area) from depressurization and compaction of clay layers interbedded in the aquifer sediments.

  5. Hydrogeochemical evolution and potability evaluation of saline contaminated coastal aquifer system of Rajnagar, Odisha, India: A geospatial perspective

    Science.gov (United States)

    Das, P. P.; Sahoo, H. K.; Mohapatra, P. P.

    2016-08-01

    The present article reports the results of a comprehensive hydrogeochemical study carried out across the coastal aquifer system of Rajnagar block, Kendrapara district, Odisha, India. The research involved collection of representative groundwater samples during the pre- and post-monsoon seasons with in situ as well as laboratory measurement of various hydrogeochemical variables. Analysis of the subsurface water samples portrays an alkali dominated water type during the pre-monsoon season whereas alkaline earth has a significantly increased influence during the post-monsoon period. However, the aquifer system displays an even distribution of strong and weak acids for both the monsoonal regimes. The hydrogeochemistry is controlled by aquifer lithology with a general occurrence of ion exchange and acid-base reaction processes across the study area. Spatial disposition of major cations indicates freshening of this coastal aquifer system in S-N and SW-NE directions. Potability analysis of the samples is suggestive of widespread unsuitability for domestic, agriculture and industrial uses. The extensive occurrence of salinity hazards, sodium hazards and magnesium hazards across the terrain makes the groundwater unsafe for domestic and agricultural utilization while industrial potability analysis suggests the aquifer system is moderately corrosive but non-incrusting. Post-monsoon however, the subsurface waters display a general decrease in hazardous nature with increased suitability for various uses.

  6. Hydrogeochemical evolution and potability evaluation of saline contaminated coastal aquifer system of Rajnagar, Odisha, India: A geospatial perspective

    Indian Academy of Sciences (India)

    P P Das; H K Sahoo; P P Mohapatra

    2016-08-01

    The present article reports the results of a comprehensive hydrogeochemical study carried out across the coastal aquifer system of Rajnagar block, Kendrapara district, Odisha, India. The research involved collection of representative groundwater samples during the pre- and post-monsoon seasons with in situas well as laboratory measurement of various hydrogeochemical variables. Analysis of the subsurface water samples portrays an alkali dominated water type during the pre-monsoon season whereas alkaline earth has a significantly increased influence during the post-monsoon period. However, the aquifer system displays an even distribution of strong and weak acids for both the monsoonal regimes. Thehydrogeochemistry is controlled by aquifer lithology with a general occurrence of ion exchange and acid–base reaction processes across the study area. Spatial disposition of major cations indicates freshening of this coastal aquifer system in S–N and SW–NE directions. Potability analysis of the samples is suggestiveof widespread unsuitability for domestic, agriculture and industrial uses. The extensive occurrence of salinity hazards, sodium hazards and magnesium hazards across the terrain makes the groundwater unsafe for domestic and agricultural utilization while industrial potability analysis suggests the aquifer system is moderately corrosive but non-incrusting. Post-monsoon however, the subsurface waters display a general decrease in hazardous nature with increased suitability for various uses.

  7. Hydrogeology of Two Areas of the Tug Hill Glacial-Drift Aquifer, Oswego County, New York

    Science.gov (United States)

    Miller, Todd S.; Bugliosi, Edward F.; Hetcher-Aguila, Kari K.; Eckhardt, David A.

    2007-01-01

    Two water-production systems, one for the Village of Pulaski and the other for the Villages of Sandy Creek and Lacona in Oswego County, New York, withdraw water from the Tug Hill glacial-drift aquifer, a regional sand and gravel aquifer along the western flank of the Tug Hill Plateau, and provide the sole source of water for these villages. As a result of concerns about contamination of the aquifer, two studies were conducted during 2001 to 2004, one for each water-production system, to refine the understanding of ground-water flow surrounding these water-production systems. Also, these studies were conducted to determine the cause of the discrepancy between ground-water ages estimated from previously constructed numerical ground-water-flow models for the Pulaski and Sandy Creek/Lacona well fields and the apparent ground-water ages determined using concentrations of tritium and chlorofluorocarbons. The Village of Pulaski withdrew 650,000 gallons per day in 2000 from four shallow, large-diameter, dug wells finished in glaciolacustrine deposits consisting of sand with some gravelly lenses 3 miles east of the village. Four 2-inch diameter test wells were installed upgradient from each production well, hydraulic heads were measured, and water samples collected and analyzed for physical properties, inorganic constituents, nutrients, bacteria, tritium, dissolved gases, and chlorofluorocarbons. Recharge to the Tug Hill glacial-drift aquifer is from precipitation directly over the aquifer and from upland sources in the eastern part of the recharge area, including (1) unchannelized runoff from till and bedrock hills east of the aquifer, (2) seepage to the aquifer from streams that drain the Tug Hill Plateau, (3) ground-water inflow from the till and bedrock on the adjoining Tug Hill Plateau. Water-quality data collected from four piezometers near the production wells in November 2003 indicated that the water is a calcium-bicarbonate type with iron concentrations that

  8. Aquifer-System Characterization by Integrating Data from the Subsurface and from Space, San Joaquin Valley, California, USA

    Science.gov (United States)

    Sneed, M.; Brandt, J. T.

    2014-12-01

    Extensive groundwater pumping from the aquifer system in the San Joaquin Valley, California, between 1926 and 1970 caused widespread aquifer-system compaction and resultant land subsidence that locally exceeded 8 m. The importation of surface water in the early 1970s resulted in decreased pumping, recovery of water levels, and a reduced rate of subsidence in some areas. Recently, land-use changes and reductions in surface-water availability have caused pumping to increase, water levels to decline, and subsidence to recur. Reduced freeboard and flow capacity of several Federal, State, and local canals have resulted from this subsidence. Vertical land-surface changes during 2005-14 in the San Joaquin Valley were determined by using space-based [Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS)] and subsurface (extensometer) data; groundwater-level and lithologic data were used to understand and estimate properties that partly control the stress/strain response of the aquifer system. Results of the InSAR analysis indicate that two areas covering about 7,200 km2 subsided 20-540 mm during 2008-10; GPS data indicate that these rates continued through 2014. Groundwater levels (stress) and vertical land-surface changes (strain) were used to estimate preconsolidation head and aquifer system storage coefficients. Integrating lithology into the analysis indicates that in some parts of the valley, the compaction occurred primarily within quickly-equilibrating fine-grained deposits in deeper parts of the aquifer system. In other parts of the valley, anomalously fine-grained alluvial-fan deposits underlie one of the most rapidly subsiding areas, indicating the shallow sediments may also contribute to total subsidence. This information helps improve hydrologic and aquifer-system compaction models, which in turn can be used to consider land subsidence as a constraint in evaluating water-resource management options.

  9. Iron in the aquifer system of Suffolk County, New York, 1990-98

    Science.gov (United States)

    Brown, Craig J.; Walter, Donald A.; Colabufo, Steven

    1999-01-01

    High concentrations of dissolved iron in ground water contribute to the biofouling of public-supply wells, and the treatment and remediation of biofouling are costly. Water companies on Long Island, N.Y., spend several million dollars annually to recondition, redevelop, and replace supply wells and distribution lines; treat dissolved iron with sequestering agents or by filtration; and respond to iron-related complaints by customers. This report summarizes the results of studies done by the U.S. Geological Survey, in cooperation with the Suffolk County Water Authority, to characterize the geochemistry and microbiology of iron in the aquifer system of Suffolk County. This information should be helpful for the siting and operation of supply wells. Concentrations of dissolved iron in Long Island?s ground water, and the frequency of iron biofouling of wells, are highest in ground-water-discharge zones, particularly near the south shore. Ground water along a deep north-south flowpath of the Magothy aquifer in southwestern Suffolk County becomes anaerobic (oxygen deficient) and Fe(III) reducing at a distance of 8 to 10 kilometers south of the ground-water divide, and this change coincides with the downgradient increase in dissolved iron concentrations. The distribution of organic carbon, and the distribution and local variations in reactivity of Fe(III), in Magothy aquifer sediments have resulted in localized differences in redox microenvironments. For example, Fe(III)-reducing zones are associated with anaerobic conditions, where relatively large amounts of Fe(III) oxyhydroxide grain coatings are present, whereas sulfate-reducing zones are associated with lignite-rich lenses of silt and clay and appear to have developed in response to the depletion of available Fe(III) oxyhydroxides. The sulfate-reducing zones are characterized by relatively low concentrations of dissolved iron (resulting from iron-disulfide precipitation) and may be large enough to warrant water

  10. 新近系松散一半胶结砂砾石含水层的注浆改造试验及效果%Neogene Loose-Weakly Cemented Sandy Gravel Aquifer Grouting Reformation Test and Effect

    Institute of Scientific and Technical Information of China (English)

    赵兰春; 李经海; 高祥川; 牛淑敏

    2012-01-01

    Safely driving through the Neogene sandy gravel is a common hard nut in inclined shaft opening out. To provide basis for surface advance grouting or concrete curtain grouting, the Xinwen Group has carried out special grouting test and pumping test, coring etc. to contrast and validated for Neogene gravel layer (intercalated with sandy clay) with total thickness 20~30m near the Heiliang coalmine main and auxiliary inclines, Shanghaimiao west mine area, Inner Mongolia. The result has demonstrated that although the loose-weakly cemented gravel layer has certain groutability beyond the IMPa grouting pressure "threshold" , but the slurry diffusive extent is less than 2~3m; also, the diffusive mode is irregular, uncontrollable and cannot form a reliable slurry diffusive consolidated ring, thus no improved effects on gravel layer water-bearing property and transmissibility have been found. Through this test, has grappled grouting performance in loose -weakly cemented gravel layer better, and obtained related grouting parameters and experiences, thus have guiding significance in grouting reformation and underground engineering construction safety in similar strata.%矿井斜井开拓安全通过新近系砂砾石含水层是一个普遍的难题,为给斜井地面预注浆或帷幕注浆法过砾石层提供依据,新矿集团在内蒙古自治区上海庙西矿区黑梁煤矿主副斜井附近对总厚20~30m的新近系砾石层(夹砂质粘土层)进行了专门注浆试验及抽水、取心等对比验证工作.结果表明,松散-半胶结砾石层虽然在超过1MPa的注浆压力“阀值”后具有一定的可注性,但浆液扩散范围小于2~3m,而且扩散方式不规则、不可控、形不成可靠的浆液扩散加固圈,对砾石层的含、导水性未发现有改善效果.通过本次试验,较好地掌握了松散-半胶结砾石层注浆性能,获得了有关注浆参数和经验,对类似地层的注浆改造和井巷工程的安全施工具有指导意义.

  11. 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...

  12. An Aquifer Thermal Energy Storage (ATES) System for Continuous and Sustainable Cold Supply in Oman

    Science.gov (United States)

    Winterleitner, G.; Schütz, F.; Huenges, E.

    2016-12-01

    The aim of the GeoSolCool research programme between the German Research Centre for Geoscience (GFZ) and The Research Council of Oman (TRC) is the development of an innovative and sustainable cooling system in combination with an aquifer thermal energy storage system in northern Oman. An integral part of this project is the design of a subsurface aquifer reservoir system for storage of thermal energy through hot water injection. An accurate characterisation of potential storage horizons is thus essential to ensure optimal efficiency of the cooling system. The study area, 40 km west of Muscat is characterised by a thick Cenozoic mixed carbonate-siliciclastic sedimentary succession, containing at least 3 aquifer horizons. We used a multidisciplinary approach for the initial ATES development phase, including geological fieldwork dovetailed with remote sensing analyses, thin-section analyses, geological modelling and reservoir fluid flow forecasting. First results indicate two potential storage horizons: (1) a Miocene-aged clastic-dominated alluvial fan system and (2) an Eocene carbonate sequence. The alluvial fan system is a more than 300 m thick, coarse clastic (mainly gravels and sandstones) succession of coalesced individual fans. Thin-section analyses showed that hydraulic parameters are favourable for the gravel and sandstone intervals but reservoir architecture is complex due to multiple generations of interconnecting fans with highly heterogeneous facies distributions. The Eocene carbonates were deposited in a carbonate ramp setting, strongly influenced by currents and storm events. Individual facies belts extend over kilometres and thus horizontal reservoir connectivity is expected to be good with minor facies variability. Thin-section analyses showed that especially the fossil-rich sections show good storage qualities. Fluid flow forecasting indicate that both potential horizons have good to very good storage characteristics. However, intense diagenetic

  13. Geologic Setting and Hydrogeologic Units of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Kahle, Sue C.; Olsen, Theresa D.; Morgan, David S.

    2009-01-01

    The Columbia Plateau Regional Aquifer System (CPRAS) covers approximately 44,000 square miles of northeastern Oregon, southeastern Washington, and western Idaho. The area supports a $6 billion per year agricultural industry, leading the Nation in production of apples and nine other commodities (State of Washington Office of Financial Management, 2007; U.S. Department of Agriculture, 2007). Groundwater availability in the aquifers of the area is a critical water-resource management issue because the water demand for agriculture, economic development, and ecological needs is high. The primary aquifers of the CPRAS are basalts of the Columbia River Basalt Group (CRBG) and overlying basin-fill sediments. Water-resources issues that have implications for future groundwater availability in the region include (1) widespread water-level declines associated with development of groundwater resources for irrigation and other uses, (2) reduction in base flow to rivers and associated effects on temperature and water quality, and (3) current and anticipated effects of global climate change on recharge, base flow, and ultimately, groundwater availability. As part of a National Groundwater Resources Program, the U.S. Geological Survey began a study of the CPRAS in 2007 with the broad goals of (1) characterizing the hydrologic status of the system, (2) identifying trends in groundwater storage and use, and (3) quantifying groundwater availability. The study approach includes documenting changes in the status of the system, quantifying the hydrologic budget for the system, updating the regional hydrogeologic framework, and developing a groundwater-flow simulation model for the system. The simulation model will be used to evaluate and test the conceptual model of the system and later to evaluate groundwater availability under alternative development and climate scenarios. The objectives of this study were to update the hydrogeologic framework for the CPRAS using the available

  14. Hydrogeologic framework and geologic structure of the Floridan aquifer system and intermediate confining unit in the Lake Okeechobee area, Florida

    Science.gov (United States)

    Reese, Ronald S.

    2014-01-01

    The successful implementation of aquifer storage and recovery (ASR) as a water-management tool requires detailed information on the hydrologic and hydraulic properties of the potential water storage zones. This report presents stratigraphic and hydrogeologic sections of the upper part of the Floridan aquifer system and the overlying confining unit or aquifer system in the Lake Okeechobee area, and contour maps of the upper contacts of the Ocala Limestone and the Arcadia Formation, which are represented in the sections. The sections and maps illustrate hydrogeologic factors such as confinement of potential storage zones, the distribution of permeability within the zones, and geologic features that may control the efficiency of injection, storage, and recovery of water, and thus may influence decisions on ASR activities in areas of interest to the Comprehensive Everglades Restoration Plan.

  15. Morphological records of storm floods exemplified by the impact of the 1872 Baltic storm on a sandy spit system in south-eastern Denmark

    DEFF Research Database (Denmark)

    Clemmensen, Lars B.; Bendixen, Mette; Hede, Mikkel U.

    2014-01-01

    Beach-ridge systems are important geo-archives providing evidence for past wave climate including catastrophic storm flood events. This study investigates the morphological impacts of the 1872 Baltic storm flood on a beach-ridge system (sandy spit) in south-eastern Denmark and evaluates...... the frequency of extreme storm flood events in the area over a longer time perspective. This paper combines field studies of morphology and sedimentary deposits, studies of historical maps, digital terrain model, ground-penetrating radar profiles, and luminescence dating. Sea water reached 2.8 m above mean sea...... level (amsl) during peak inundation and, based on studies of the morphological impacts of the 1872 storm flood, the event can be divided into four phases. Phase 1: increasing mean water levels and wave activity at the beach brought sediments from the beach (intertidal bars and normal berm) higher up...

  16. Nitrogen fertilization on soybean under crop-livestock system and sandy soil = Nitrogênio mineral na soja integrada com a pecuária em solo arenoso

    Directory of Open Access Journals (Sweden)

    Alvadi Antonio Balbinot Junior

    2016-07-01

    Full Text Available In Brazil, soybean has been introduced in areas with sandy soil and tropical climate, often under crop-livestock system. The use of nitrogen (N for this crop is supplied by the soil organic matter mineralization and the biological N fixation. However, there are questions about the effect of nitrogen fertilization in soybean crop under sandy soils with a high amount of straw. The aim of this study was to evaluate the agronomic performance of two soybean cultivars in different doses (20 and 45 kg N ha-1 and application times (sowing, at flowering or early grain filling of N in sandy soil with high amount of Urochloa brizantha straw. Two experiments were conducted in Northwest of Paraná state, Brazil, the first experiment with the BMX Potência RR cultivar and the second one with the BRS 360 RR cultivar, in a sandy soil (11% clay. The experiment were composed by seven treatments (interaction between factors and the control, settled in a randomized block design with four replications. In sandy soil, with high amount of U. brizantha straw, the nitrogen fertilizer applied at different doses and at soybean development stages, cultivars BMX Potência RR and BRS 360 RR, does not influence the photoassimilates partition between stem and leaves, foliar N concentration, yield, yield components, and the oil and protein content in the grains. = No Brasil, a soja tem sido introduzida em regiões que apresentam solos arenosos e clima tropical, sendo muitas vezes integrada com a pecuária. A demanda da oleaginosa por nitrogênio(N é suprida pela mineralização da matéria orgânica do solo e pela fixação biológica do N. No entanto, há questionamentos quanto ao efeito da adubação nitrogenada na cultura da soja cultivada em solos arenosos, com alta quantidade de palha de gramíneas. Objetivou-se com este trabalho avaliar o desempenho de duas cultivares de soja, em solo arenoso, após dois anos com pastagem de Urochloa brizantha, submetidas a diferentes

  17. Semi-analytical solutions for flow to a well in an unconfined-fractured aquifer system

    Science.gov (United States)

    Sedghi, Mohammad M.; Samani, Nozar

    2015-09-01

    Semi-analytical solutions of flow to a well in an unconfined single porosity aquifer underlain by a fractured double porosity aquifer, both of infinite radial extent, are obtained. The upper aquifer is pumped at a constant rate from a pumping well of infinitesimal radius. The solutions are obtained via Laplace and Hankel transforms and are then numerically inverted to time domain solutions using the de Hoog et al. algorithm and Gaussian quadrature. The results are presented in the form of dimensionless type curves. The solution takes into account the effects of pumping well partial penetration, water table with instantaneous drainage, leakage with storage in the lower aquifer into the upper aquifer, and storativity and hydraulic conductivity of both fractures and matrix blocks. Both spheres and slab-shaped matrix blocks are considered. The effects of the underlying fractured aquifer hydraulic parameters on the dimensionless drawdown produced by the pumping well in the overlying unconfined aquifer are examined. The presented solution can be used to estimate hydraulic parameters of the unconfined and the underlying fractured aquifer by type curve matching techniques or with automated optimization algorithms. Errors arising from ignoring the underlying fractured aquifer in the drawdown distribution in the unconfined aquifer are also investigated.

  18. A Laboratory Scale Aquifer-Well System for Analyzing Near-well Processes

    Science.gov (United States)

    Kalwa, Fritz; Bonilla, José; Händel, Falk; Binder, Martin; Stefan, Catalin

    2016-04-01

    Managed Aquifer Recharge (MAR) is constantly gaining popularity and one very promising technique in this context is infiltration by vertical wells. However, the near-well surrounding of these wells is still object of many open questions, related to - among others - clogging, screen design and the effects of underground heterogeneities. As a tool for a better understanding of these processes, a physical laboratory-scale aquifer-well model was designed. The physical model was assembled in a cylindrical tank with a height of 1.1 m and a diameter of 1 m. Water can be introduced via a small-diameter well screen (inner diameter: 2.54 cm) in the center of the tank and leaves the system via side outlets. These outlets were connected hydraulically to a single outflow system, allowing the adjustment of the same outflow head for all side outlets. Furthermore, a drainage system was attached to the tank's wall to assure circular flow from the well to the wall. The drainage system was chosen after preliminary tests of different drainage materials to determine the best performing setup. Remaining impoundment heights of up to 30 cm were observed in the tank, due to pressure losses at the outflow system. To include the resulting impoundment into a numerical model using Hydrus 2D/3D, a half-empirical formula was derived, plotting impoundment heights against infiltration rates and considering the pressure losses in the outflow system as well as in the drainage layer. Using the predicted impoundment heights for correction, the numerical model allowed satisfying simulation of the flow pattern in the tank for infiltration rates. The study shows how to develop an approach combining numerical and physical modeling as a base for future investigation of near-well processes under well-defined laboratory conditions.

  19. A multi-tracer study in the Hutton Sandstone aquifer, Australia: How "wrong ages" give us deeper insights into aquifer structure and effective deep recharge to a double porosity system

    Science.gov (United States)

    Suckow, Axel; Taylor, Andrew; Davies, Phil; Leaney, Fred

    2017-04-01

    Depressurisation of coal seams in the Walloon Coal Measures in Queensland, Australia, may influence aquifers both over- and underlying the formation. The Gubberamunda Sandstone aquifer, which overlies the Walloon Coal Measures, is the starting point of the Great Artesian Basin (GAB) flow system and has been the focus of numerous recharge studies. In comparison, the Hutton Sandstone aquifer, which underlies the Walloon Coal Measures, has received much less attention. This aquifer however, is the main supply of stock water for the beef industry in the area. A multi-environmental tracer study of the Hutton Sandstone aquifer was undertaken at the Mimosa Syncline and was complemented by a few samples taken from the underlying Precipice Sandstone aquifer. This multi-tracer study (comprising 18O, 2H, 3H, CFCs, SF6, 14C, 36Cl, and 4He) demonstrated that the Hutton Sandstone aquifer behaves as a double porosity system. At the regional scale, the system features a relatively small fraction of conductive rock within a fairly large fraction of low permeability rock. Tracer migration therefore occurs mainly by advection in the conductive fraction and mainly by diffusion in the low-permeability fraction of the aquifer. Groundwater flow velocities, derived from exponential decrease of 14C and 36Cl concentrations with distance, differ by a factor of ten and therefore do not indicate the real groundwater flow velocity. However, accounting for a double porosity interpretation of the tracer data leads to a single groundwater flow velocity that is consistent with all observed data. Advective velocity in this double porosity model differs from face value flow velocities derived from 14C and 36Cl by a factor of 4 and 40 respectively. As a consequence of this interpretation, the deeper groundwater flow system of the Hutton Sandstone aquifer is estimated to receive only 3% of the recharge previously estimated using the Chloride Mass Balance approach at the intake beds. The other 97% is

  20. Sustainable development and management of an aquifer system in western Turkey

    Science.gov (United States)

    Sakiyan, Jale; Yazicigil, Hasan

    This study presents the establishment of sustainable development and management policies for the Küçük Menderes River Basin aquifer system in western Turkey. Geological, hydrogeological, and geophysical data are used conjunctively to define various hydrogeological units and their geometry. Distributions of hydraulic-parameter values and recharge are estimated by geostatistical methods and hydrologic simulations, respectively. A finite-difference groundwater flow model is used to represent the unconfined flow in the aquifer system. The model has been calibrated under steady state and transient conditions. The resulting model was used to test seven management scenarios for a planning period of 21 years to determine the so-called safe yield and sustainable yield of the aquifer system and to investigate the potential impacts of four planned surface water reservoirs on groundwater resources in the basin. The results demonstrate that the continuation of the present pumping rates exceeds both the safe yield and the sustainable yield of the aquifer system. Consequently, the growing need for irrigation water should be met by the construction of the planned surface water reservoirs and the implementation of efficient water management policies and plans. Cette étude présente la proposition d'une politique de développement et de gestion durables du système aquifère du bassin du Petit Mendérès dans l'ouest de la Turquie. Des données géologiques, hydrogéologiques et géophysiques ont été utilisées conjointement pour définir les différentes unités hydrogéologiques et leur géométrie. Les distributions des paramètres hydrauliques et de la recharge ont été estimées respectivement par des méthodes géostatistiques et des simulations hydrologiques. Un modèle d'écoulement souterrain aux éléments finis a été utilisé pour représenter l'écoulement non captif dans le système aquifère. Le modèle a été calibré dans des conditions de r

  1. Hydrostratigraphic Framework and Selection and Correlation of Geophysical Log Markers in the Surficial Aquifer System, Palm Beach County, Florida

    Science.gov (United States)

    Reese, Ronald S.; Wacker, Michael A.

    2007-01-01

    The surficial aquifer system is the major source of freshwater for public water supply in Palm Beach County, Florida, yet many previous studies of the hydrogeology of this aquifer system have focused only on the eastern one-half to one-third of the county in the more densely populated coastal area (Land and others, 1973; Swayze and others, 1980; Swayze and Miller, 1984; Shine and others, 1989). Population growth in the county has resulted in the westward expansion of urbanized areas into agricultural areas and has created new demands on the water resources of the county. Additionally, interest in surface-water resources of central and western areas of the county has increased. In these areas, plans for additional surface-water storage reservoirs are being made under the Comprehensive Everglades Restoration Plan originally proposed by the U.S. Army Corps of Engineers and the South Florida Water Management District (1999), and stormwater treatment areas have been constructed by the South Florida Water Management District. Surface-water and ground-water interactions in the Everglades are thought to be important to water budgets, water quality, and ecology (Harvey and others, 2002). Most of the previous hydrogeologic and ground-water flow simulation studies of the surficial aquifer system have not utilized a hydrostratigraphic framework, in which stratigraphic or sequence stratigraphic units, such as those proposed in Cunningham and others (2001), are delineated in this stratigraphically complex aquifer system. A thick zone of secondary permeability mapped by Swayze and Miller (1984) was not subdivided and was identified as only being within the Anastasia Formation of Pleistocene age. Miller (1987) published 11 geologic sections of the surficial aquifer system, but did not delineate any named stratigraphic units in these sections. This limited interpretation has resulted, in part, from the complex facies changes within rocks and sediments of the surficial aquifer

  2. Numerical analysis of the hydrogeologic controls in a layered coastal aquifer system, Oahu, Hawaii, USA

    Science.gov (United States)

    Oki, Delwyn S.; Souza, William R.; Bolke, Edward L.; Bauer, Glenn R.

    The coastal aquifer system of southern Oahu, Hawaii, USA, consists of highly permeable volcanic aquifers overlain by weathered volcanic rocks and interbedded marine and terrestrial sediments of both high and low permeability. The weathered volcanic rocks and sediments are collectively known as caprock, because they impede the free discharge of groundwater from the underlying volcanic aquifers. A cross-sectional groundwater flow and transport model was used to evaluate the hydrogeologic controls on the regional flow system in southwestern Oahu. Controls considered were: (a) overall caprock hydraulic conductivity; and (b) stratigraphic variations of hydraulic conductivity in the caprock. Within the caprock, variations in hydraulic conductivity, caused by stratigraphy or discontinuities of the stratigraphic units, are a major control on the direction of groundwater flow and the distribution of water levels and salinity. Results of cross-sectional modeling confirm the general groundwater flow pattern that would be expected in a layered coastal system. Groundwater flow is: (a) predominantly upward in the low-permeability sedimentary units; and (b) predominantly horizontal in the high-permeability sedimentary units. Résumé Le système aquifère littoral du sud d'Oahu (Hawaii, États-Unis) est constitué par des aquifères de terrains volcaniques très perméables, recouverts par des roches volcaniques altérées, et interstratifiés avec des sédiments marins et continentaux de perméabilité aussi bien forte que faible. Les roches volcaniques altérées et les sédiments sont globalement considérés comme une couverture, parce qu'ils s'opposent à l'écoulement de l'eau souterraine provenant des aquifères volcaniques sous-jacents. Les contrôles hydrogéologiques sur le système aquifère régional du sud-ouest d'Oahu ont étéévaluées au moyen d'un modèle d'écoulement et de transport sur une section transversale. Ces contrôles prennent en compte la conductivit

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

    Science.gov (United States)

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

    2013-04-01

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

  4. Water resources of the Southern Hills regional aquifer system, southeastern Louisiana

    Science.gov (United States)

    White, Vincent E.

    2017-03-01

    Information concerning the availability, use, and quality of groundwater in the 10 parishes overlying the Southern Hills regional aquifer system of Louisiana (fig. 1) is critical for water-supply management. The purpose of this fact sheet is to present information that can be used by water managers, residents, and others for stewardship of this vital resource. Information on the availability, past and current use, use trends, and water quality from groundwater sources in these parishes is presented. Previously published reports (see References Cited section) and data stored in the U.S. Geological Survey’s National Water Information System (U.S. Geological Survey, 2017) are the primary sources of the information presented here.

  5. Interaction of cold-water aquifers with exploited reservoirs of the Cerro Prieto geothermal system

    Science.gov (United States)

    Truesdell, Alfred; Lippmann, Marcelo

    1990-01-01

    Cerro Prieto geothermal reservoirs tend to exhibit good hydraulic communication with adjacent cool groundwater aquifers. Under natural state conditions the hot fluids mix with the surrounding colder waters along the margins of the geothermal system, or discharge to shallow levels by flowing up fault L. In response to exploitation reservoir pressures decrease, leading to changes in the fluid flow pattern in the system and to groundwater influx. The various Cerro Prieto reservoirs have responded differently to production, showing localized near-well or generalized boiling, depending on their access to cool-water recharge. Significant cooling by dilution with groundwater has only been observed in wells located near the edges of the field. In general, entry of cool water at Cerro Prieto is beneficial because it tends to maintain reservoir pressures, restrict boiling, and lengthen the life and productivity of wells.

  6. Steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system

    Science.gov (United States)

    Brooks, Lynette E.; Masbruch, Melissa D.; Sweetkind, Donald S.; Buto, Susan G.

    2014-01-01

    This report describes the construction, calibration, evaluation, and results of a steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system that was developed as part of the U.S. Geological Survey National Water Census Initiative to evaluate the nation’s groundwater availability. The study area spans 110,000 square miles across five states. The numerical model uses MODFLOW-2005, and incorporates and tests complex hydrogeologic and hydrologic elements of a conceptual understanding of an interconnected groundwater system throughout the region, including mountains, basins, consolidated rocks, and basin fill. The level of discretization in this model has not been previously available throughout the study area.

  7. "Groundwater ages" of the Lake Chad multi-layer aquifers system inferred from 14C and 36Cl data

    Science.gov (United States)

    Bouchez, Camille; Deschamps, Pierre; Goncalves, Julio; Hamelin, Bruno; Seidel, Jean-Luc; Doumnang, Jean-Claude

    2014-05-01

    Assessment of recharge, paleo-recharge and groundwater residence time of aquifer systems of the Sahel is pivotal for a sustainable management of this vulnerable resource. Due to its stratified aquifer system, the Lake Chad Basin (LCB) offers the opportunity to assess recharge processes over time and to link climate and hydrology in the Sahel. Located in north-central Africa at the fringe between the Sahel and the Sahara, the lake Chad basin (LCB) is an endorheic basin of 2,5.106 km2. With a monsoon climate, the majority of the rainfall occurs in the southern one third of the basin, the Chari/Logone River system transporting about 90% of the runoff generated within the drainage basin. A complex multi-layer aquifer system is located in the central part of the LCB. The Quaternary unconfined aquifer, covering 500 000 km2, is characterized by the occurrence of poorly understood piezometric depressions. Artesian groundwaters are found in the Plio-Pleistocene lacustrine and deltaic sedimentary aquifers (early Pliocene and Continental Terminal). The present-day lake is in hydraulic contact with the Quaternary Aquifer, but during past megalake phases, most of the Quaternary aquifer was submerged and may experience major recharge events. To identify active recharge area and assess groundwater dynamics, one hundred surface and groundwater samples of all layers have been collected over the southern part of the LCB. Major and trace elements have been analyzed. Measurements of 36Cl have been carried out at CEREGE, on the French 5 MV AMS National Facility ASTER and 14C activities have been analyzed for 17 samples on the French AMS ARTEMIS. Additionally, the stable isotopic composition was measured on the artesian aquifer samples. In the Quaternary aquifer, results show a large scatter with waters having very different isotopic and geochemical signature. In its southern part and in the vicinity of the surface waters, groundwaters are predominantly Ca-Mg-HCO3 type waters with very

  8. Hydrogeology of the Susquehanna River valley-fill aquifer system in the Endicott-Vestal area of southwestern Broome County, New York

    Science.gov (United States)

    Randall, Allan D.; Kappel, William M.

    2015-07-29

    The village of Endicott, New York, and the adjacent town of Vestal have historically used groundwater from the Susquehanna River valley-fill aquifer system for municipal water supply, but parts of some aquifers in this urban area suffer from legacy contamination from varied sources. Endicott would like to identify sites distant from known contamination where productive aquifers could supply municipal wells with water that would not require intensive treatment. The distribution or geometry of aquifers within the Susquehanna River valley fill in western Endicott and northwestern Vestal are delineated in this report largely on the basis of abundant borehole data that have been compiled in a table of well records.

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

    Science.gov (United States)

    Watney, W. L.; Rush, J.

    2011-12-01

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

  10. Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina

    Science.gov (United States)

    Williams, Lester J.; Dixon, Joann F.

    2015-01-01

    Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part of the U.S. Geological Survey Groundwater Resources Program. The dataset contains structural surfaces depicting the top and base of the aquifer system, its major and minor hydrogeologic units and zones, geophysical marker horizons, and the altitude of the 10,000-milligram-per-liter total dissolved solids boundary that defines the approximate fresh and saline parts of the aquifer system. The thicknesses of selected major and minor units or zones were determined by interpolating points of known thickness or from raster surface subtraction of the structural surfaces. Additional data contained include clipping polygons; regional polygon features that represent geologic or hydrogeologic aspects of the aquifers and the minor units or zones; data points used in the interpolation; and polygon and line features that represent faults, boundaries, and other features in the aquifer system.

  11. Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

    Science.gov (United States)

    Lindholm, G.F.

    1996-01-01

    Regional aquifers underlying the 15,600-square-mile Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. The largest and most productive aquifers in the Snake River Plain are composed of Quaternary basalt of the Snake River Group, which underlies most of the 10,8000-square-mile eastern plain. Aquifer tests and simulation indicate that transmissivity of the upper 200 feet of the basalt aquifer in the eastern plain commonly ranges from about 100,000 to 1,000,000 feet squared per day. However, transmissivity of the total aquifer thickness may be as much as 10 million feet squared per day. Specific yield of the upper 200 feet of the aquifer ranges from about 0.01 to 0.20. Average horizontal hydraulic conductivity of the upper 200 feet of the basalt aquifer ranges from less than 100 to 9,000 feet per day. Values may be one to several orders of magnitude higher in parts in individual flows, such as flow tops. Vertical hydraulic conductivity is probably several orders of magnitude lower than horizontal hydraulic conductivity and is generally related to the number of joints. Pillow lava in ancestral Snake River channels has the highest hydraulic conductivity of all rock types. Hydraulic conductivity of the basalt decreases with depth because of secondary filling of voids with calcite and silica. An estimated 80 to 120 million acre-feet of water is believed to be stored in the upper 200 feet of the basalt aquifer in the eastern plain. The most productive aquifers in the 4,800-square-mile western plain are alluvial sand and gravel in the Boise River valley. Although aquifer tests indicate that transmissivity of alluvium in the Boise River valley ranges from 5,000 to 160,000 feet squared per day, simulation suggests that average transmissivity of the upper 500 feet is generally less than 20,000 feet squared per day. Vertically averaged horizontal hydraulic conductivity of the upper

  12. Preliminary investigation of groundwater flow and trichloroethene transport in the Surficial Aquifer System, Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota

    Science.gov (United States)

    King, Jeffrey N.; Davis, J. Hal

    2016-05-16

    Industrial practices at the Naval Industrial Reserve Ordnance Plant, in Fridley, Minnesota, caused soil and groundwater contamination. Some volatile organic compounds from the plant might have discharged to the Mississippi River, forced by the natural hydraulic gradient in the surficial aquifer system. The U.S. Environmental Protection Agency included the Naval Industrial Reserve Ordnance Plant on the Superfund National Priorities List in 1989.

  13. A Semi-Analytical Solution for Large-Scale Injection-Induced PressurePerturbation and Leakage in a Laterally Bounded Aquifer-AquitardSystem

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Quanlin; Birkholzer, Jens T.; Tsang, Chin-Fu

    2008-07-15

    A number of (semi-)analytical solutions are available to drawdown analysis and leakage estimation of shallow aquifer-aquitard systems. These solutions assume that the systems are laterally infinite. When a large-scale pumping from (or injection into) an aquifer-aquitard system of lower specific storativity occurs, induced pressure perturbation (or hydraulic head drawdown/rise) may reach the lateral boundary of the aquifer. We developed semi-analytical solutions to address the induced pressure perturbation and vertical leakage in a 'laterally bounded' system consisting of an aquifer and an overlying/underlying aquitard. A one-dimensional radial flow equation for the aquifer was coupled with a one-dimensional vertical flow equation for the aquitard, with a no-flow condition imposed on the outer radial boundary. Analytical solutions were obtained for (1) the Laplace-transform hydraulic head drawdown/rise in the aquifer and in the aquitard, (2) the Laplace-transform rate and volume of leakage through the aquifer-aquitard interface integrated up to an arbitrary radial distance, (3) the transformed total leakage rate and volume for the entire interface, and (4) the transformed horizontal flux at any radius. The total leakage rate and volume depend only on the hydrogeologic properties and thicknesses of the aquifer and aquitard, as well as the duration of pumping or injection. It was proven that the total leakage rate and volume are independent of the aquifer's radial extent and wellbore radius. The derived analytical solutions for bounded systems are the generalized solutions of infinite systems. Laplace-transform solutions were numerically inverted to obtain the hydraulic head drawdown/rise, leakage rate, leakage volume, and horizontal flux for given hydrogeologic and geometric conditions of the aquifer-aquitard system, as well as injection/pumping scenarios. Application to a large-scale injection-and-storage problem in a bounded system was demonstrated.

  14. Tabulated Transmissivity and Storage Properties of the Floridan Aquifer System in Florida and Parts of Georgia, South Carolina, and Alabama

    Science.gov (United States)

    Kuniansky, Eve L.; Bellino, Jason C.

    2012-04-19

    A goal of the U.S. Geological Survey Groundwater Resources Program is to assess the availability of fresh water within each of the principal aquifers in the United States with the greatest groundwater withdrawals. The Floridan aquifer system (FAS), which covers an area of approximately 100,000 square miles in Florida and parts of Georgia, Alabama, Mississippi, and South Carolina, is one such principal aquifer, having the fifth largest groundwater withdrawals in the Nation, totaling 3.64 billion gallons per day in 2000. Compilation of FAS hydraulic properties is critical to the development and calibration of groundwater flow models that can be used to develop water budgets spatially and temporally, as well as to evaluate resource changes over time. Wells with aquifer test data were identified as Upper Floridan aquifer (UFA), Lower Floridan aquifer (LFA), Floridan aquifer system (FAS, Upper Floridan with some middle and/or Lower Floridan), or middle Floridan confining unit (MCU), based on the identification from the original database or report description, or comparison of the open interval of the well with previously published maps.This report consolidates aquifer hydraulic property data obtained from multiple databases and reports of the U.S. Geological Survey, various State agencies, and the Water Management Districts of Florida, that are compiled into tables to provide a single information source for transmissivity and storage properties of the FAS as of October 2011. Transmissivity calculated from aquifer pumping tests and specific-capacity data are included. Values for transmissivity and storage coefficients are intended for use in regional or sub regional groundwater flow models; thus, any tests (aquifer pumping tests and specific capacity data) that were conducted with packers or for open intervals less than 30 feet in length are excluded from the summary statistics and tables of this report, but are included in the database.The transmissivity distribution

  15. Groundwater-flow model for the Wood River Valley aquifer system, south-central Idaho

    Science.gov (United States)

    Fisher, Jason C.; Bartolino, James R.; Wylie, Allan H.; Sukow, Jennifer; McVay, Michael

    2016-06-27

    A three-dimensional numerical model of groundwater flow was developed for the Wood River Valley (WRV) aquifer system, Idaho, to evaluate groundwater and surface-water availability at the regional scale. This mountain valley is located in Blaine County and has a drainage area of about 2,300 square kilometers (888 square miles). The model described in this report can serve as a tool for water-rights administration and water-resource management and planning. The model was completed with support from the Idaho Department of Water Resources, and is part of an ongoing U.S. Geological Survey effort to characterize the groundwater resources of the WRV. A highly reproducible approach was taken for constructing the WRV groundwater-flow model. The collection of datasets, source code, and processing instructions used to construct and analyze the model was distributed as an R statistical-computing and graphics package.

  16. Speciation and interactions of plutonium with humic substances and kaolinite in aquifer systems

    Energy Technology Data Exchange (ETDEWEB)

    Banik, N.L. [Institut fuer Kernchemie, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany)], E-mail: banik@uni-mainz.de; Buda, R.A. [Institut fuer Kernchemie, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Buerger, S. [Oak Ridge National Laboratory, Chemical and Isotope Mass Spectrometry Group, Transuranium Research Institute, Oak Ridge TN 37831 (United States); Kratz, J.V. [Institut fuer Kernchemie, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany)], E-mail: JVKratz@uni-mainz.de; Trautmann, N. [Institut fuer Kernchemie, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany)

    2007-10-11

    The speciation of plutonium (Pu) in contact with humic substances (HS) and kaolinite has been performed in aquifer systems. Mainly the redox behavior, complexation, and sorption of plutonium are discussed here. The redox behavior of Pu(VI) in contact with HS was studied and it was found that Pu(VI) is reduced to Pu(III) and Pu(IV) within a couple of weeks. The complexation constants (log {beta}{sub LC}) of Pu(III) and Pu(IV) with HS have been determined by means of the ultrafiltration method. Furthermore, the sorption of Pu(III) and Pu(IV) onto kaolinite has been investigated as a function of pH by batch experiments under aerobic and anaerobic conditions.

  17. Identification and management of potential problems in aquifer thermal energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Michel, F.A. [Carleton Univ., Ottawa, ON (Canada); Allen, D.M. [Simon Fraser Univ., Burnaby, BC (Canada)

    2003-07-01

    There is renewed interest in alternative renewable energy sources because of high energy prices, shortages in peak load electrical supplies, and environmental considerations. Worldwide efforts are being made to extract thermal energy from the ground for heating and cooling individual dwellings and industrial and institutional complexes. Aquifer thermal energy storage systems offer a viable option. Often, there is a poor understanding of the problems associated with the well field, resulting in resistance in the consideration and implementation of the technology. Well-field problems include pressure build-up in the reinjection wells resulting in reduced flow conditions. Other problems associated with well-field configuration include wellbore clogging due to sediment accumulation, scaling, degassing or bio-fouling. These problems are often associated with changes in temperature and pressure. The authors examined these problems and presented guidelines to assist in the identification and management of the potential problems. 2 refs., 1 fig.

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

    Science.gov (United States)

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

    2008-01-01

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

  19. The impact of low-temperature seasonal aquifer thermal energy storage (SATES) systems on chlorinated solvent contaminated groundwater: Modeling of spreading and degradation

    NARCIS (Netherlands)

    Zuurbier, K.G.; Hartog, N.; Valstar, J.; Post, V.E.A.; Breukelen, B.M. van

    2013-01-01

    Groundwater systems are increasingly used for seasonal aquifer thermal energy storage (SATES) for periodic heating and cooling of buildings. Its use is hampered in contaminated aquifers because of the potential environmental risks associated with the spreading of contaminated groundwater, but positi

  20. Using a Geographic Information System to Assess Site Suitability for Managed Aquifer Recharge using Stormwater Capture

    Science.gov (United States)

    Teo, E. K.; Harmon, R. E.; Beganskas, S.; Young, K. S.; Fisher, A. T.; Weir, W. B.; Lozano, S.

    2015-12-01

    We are completing a regional analysis of Santa Cruz and northern Monterey Counties, CA, to assess the conditions amenable to managed aquifer recharge using stormwater runoff. Communities and water supply agencies across CA are struggling to mitigate the ongoing drought and to develop secure and sustainable water supplies to support long-term municipal, agricultural, environmental and other needs. Enhanced storage of groundwater is an important part of this effort in many basins. This work is especially timely because of the recently enacted "Sustainable Groundwater Management Act" (SGMA), which requires the development of groundwater sustainability agencies and implementation of basin management plans in coming decades. Our analysis focuses specifically on the distributed collection of stormwater runoff, a water source that has typically been treated as a nuisance or waste, from drainages having an area on the order of 40-160 hectares. The first part of this project is a geographic information system (GIS) analysis using surface and subsurface data sets. Developing complete and accurate datasets across the study region required considerable effort to locate, assemble, co-register, patch, and reconcile information from many sources and scales. We have complete spatial coverage for surface data, but subsurface data is more limited in lateral extent. Sites that are most suitable for distributed stormwater capture supporting MAR have high soil infiltration capacity, are well-connected to an underlying aquifer with good transmissive and storage properties, and have space to receive MAR. Additional considerations include method of infiltration, slope, and land use and access. Based on initial consideration of surface data and slope, 7% of the complete study region appears to be "suitable or highly suitable" for MAR (in the top third of the rating system), but there is considerable spatial heterogeneity based on the distribution of shallow soils and bedrock geology.

  1. Geochemical Evolution of Induced Infiltration in a River-Recharged Aquifer System: Fredericton, New Brunswick, Canada

    Science.gov (United States)

    Al, T.; Amskold, L.

    2004-05-01

    The city of Fredericton, New Brunswick, Canada relies on groundwater from a glacial aquifer in the Saint John River valley. The aquifer is a semi-confined esker discontinuously overlain by clay/silt of glacio-lacustrine and/or marine origin. Recharge to the well field occurs partly from the adjacent river where a discontinuity in the confining layer allows for hydraulic connection with the river. It has been suggested that elevated Mn concentrations in the groundwater supply are related to reductive dissolution of Mn-oxide minerals in the aquifer as a result of the infiltration of dissolved organic carbon from the river. A detailed hydrogeochemical study has been conducted to investigate redox conditions along a flow path from the river bed to a nearby water-supply well. Aqueous geochemical data from multi-level piezometers along the flow path display variations in redox-sensitive solutes (O2, NO3, Mn, Fe, SO4 and HS) in space and time. The redox conditions cycle on a seasonal time scale, likely in response to temperature changes in the infiltrating river water. In the spring and early summer the conditions are relatively oxidizing with elevated concentrations of dissolved O2 and NO3, and low concentrations of Mn and Fe. Toward late summer, and into the fall, the system tends toward more reducing conditions, with concentrations of dissolved O2 and NO3 declining, and concentrations of Mn and Fe increasing. Localized zones of elevated HS concentrations suggest that SO4 reduction occurs, however, the seasonal trend toward reducing conditions is not manifest by a widespread decline in SO4 concentrations as it is for O2 and NO3. The data are generally consistent with trends that are expected based on thermodynamics, with O2 reduction followed by NO3, MnIV, FeIII and SO4 reduction, however, in some locations these respective redox zones are superimposed. The observed overlap of redox zones is likely attributable to a combination of variable reaction kinetics (probably

  2. Estimation of hydraulic parameters in a complex porous aquifer system using geoelectrical methods.

    Science.gov (United States)

    Kazakis, N; Vargemezis, G; Voudouris, K S

    2016-04-15

    Geoelectrical methods have been widely used for the estimation of aquifer hydraulic properties. In this study, geoelectrical methods were applied in a lithologically and hydrochemically complex porous aquifer to estimate its porosity, hydraulic conductivity and transmissivity. For this purpose, the electrical resistivity of the aquifer as well as the electrical conductivity of the groundwater was measured in 37 sites and wells. Initially, the Archie's law was used to generate sets of cementation factor (m) and alpha (α) parameter from which the mode values of α=0.98 and m=1.75 are representative of the studied aquifer. The transmissivity of the aquifer varies from 5.1×10(-3) to 3.1×10(-5)m(2)/s, whereas the mean value of its porosity is 0.45. The hydraulic conductivity of the aquifer which was calculated according to Archie's law varies from 2.08×10(-6) to 6.84×10(-5)m/s and is strongly correlated with the pumping test's hydraulic conductivity. In contrast, the hydraulic conductivity which was calculated using Dar-Zarrouk parameters presents lower correlation with the pumping test's hydraulic conductivity. Furthermore, a relation between aquifer resistivity and hydraulic conductivity was established for the studied aquifer to enable the estimation of these parameters in sites lacking data.

  3. Geohydrology and Water Quality of the Valley-Fill Aquifer System in the Upper Sixmile Creek and West Branch Owego Creek Valleys in the Town of Caroline, Tompkins County, New York

    Science.gov (United States)

    Miller, Todd S.

    2009-01-01

    In 2002, the U.S. Geological Survey, in cooperation with the Town of Caroline and Tompkins County Planning Department, began a study of the valley-fill aquifer system in upper Sixmile Creek and headwaters of West Branch Owego Creek valleys in the Town of Caroline, NY. The purpose of the study is to provide geohydrologic data to county and town planners as they develop a strategy to manage and protect their water resources. The first aquifer reach investigated in this series is in the Town of Caroline and includes the upper Sixmile Creek valley and part of West Branch Owego Creek valley. The portions of the valley-fill aquifer system that are comprised of saturated coarse-grained sediments including medium to coarse sand and sandy gravel form the major aquifers. Confined sand and gravel units form the major aquifers in the western and central portions of the upper Sixmile Creek valley, and an unconfined sand and gravel unit forms the major aquifer in the eastern portion of the upper Sixmile Creek valley and in the headwaters of the West Branch Owego Creek valley. The valley-fill deposits are thinnest near the edges of the valley where they pinch out along the till-mantled bedrock valley walls. The thickness of the valley fill in the deepest part of the valley, at the western end of the study area, is about 100 feet (ft); the thickness is greater than 165 ft on top of the Valley Heads Moraine in the central part of the valley. An estimated 750 people live over and rely on groundwater from the valley-fill aquifers in upper Sixmile Creek and West Branch Owego Creek valleys. Most groundwater withdrawn from the valley-fill aquifers is pumped from wells with open-ended 6-inch diameter casings; the remaining withdrawals are from shallow dug wells or cisterns that collect groundwater that discharges to springs (especially in the Brooktondale area). The valley-fill aquifers are the sources of water for about 200 households, several apartment complexes, two mobile home parks

  4. Finding palaeowaters in a multi-layered aquifer system in the Lom depression of Danubian Plain in Bulgaria

    Science.gov (United States)

    Túri, Marianna; Palcsu, László; Molnár, Mihály; Futó, István; Orehova, Tatiana; Toteva, Aglaida; Hristov, Vladimir; Benderev, Aleksey

    2017-04-01

    This work is an environmental isotope investigation of groundwater samples from a multi-layered aquifer system in the Lom depression of Danubian Plain in Bulgaria. Our previous studies in the Carpathian-Pannonian Region had been convinced through groundwater researches using noble gas temperatures that the recharge temperature difference between the Holocene and the late Pleistocene recharged waters is 9.13±0.89°C. The aim of this research in Bulgaria is to observe this phenomenon at the outside of the Carpathian-Pannonian Region. The purpose of the sampling campaign was to find out that one of the aquifers of the Lom depression could be a potential site for late Pleistocene, and Holocene paleoclimate reconstruction. There are water samples from the Dacian-Romanian complex, Upper-Pontian aquifer, Meotian-Lower Pontian aquitard and the Sarmatian aquifer as well. The collected water samples were examined for water chemistry, stable carbon, oxygen and hydrogen isotopes, and for noble gas concentrations, and besides them for radiocarbon and tritium. The radiocarbon content of the water samples are in the range from 15.9 pMC to 98.6 pMC. Based on the obtained radiocarbon values it can be stated that tree aquifers of four could be contain such waters which recharged during the early Holocene late Pleistocene (Pontian, Dacian, Sarmatian). There are two wells in the Pontian aquifer (Dolni Tsibar, 20.8 pMC; Agroinvest, 23.8 pMC) with lower radiocarbon content. Based on the stable oxygen composition of the Agroinvest well, which is with -14.2 ‰ more negative than the others so it can be late Pleistocene recharged water. In the Dacian aquifer might be one well, the Valchedram which can be late Pleistocene recharged with 23.7 pMC. In the Sarmatian aquifer can be find the oldest water sample from all with 15.9 pMC of Smirnenski. The obtained noble gas temperatures and tritium values might be stated this hypothesis as well. All measurements were carried out in Hertelendi

  5. A reactive transport model for the quantification of risks induced by groundwater heat pump systems in urban aquifers

    Science.gov (United States)

    García-Gil, Alejandro; Epting, Jannis; Ayora, Carlos; Garrido, Eduardo; Vázquez-Suñé, Enric; Huggenberger, Peter; Gimenez, Ana Cristina

    2016-11-01

    Shallow geothermal resource exploitation through the use of groundwater heat pump systems not only has hydraulic and thermal effects on the environment but also induces physicochemical changes that can compromise the operability of installations. This study focuses on chemical clogging and dissolution subsidence processes observed during the geothermal re-injection of pumped groundwater into an urban aquifer. To explain these phenomena, two transient reactive transport models of a groundwater heat pump installation in an alluvial aquifer were used to reproduce groundwater-solid matrix interactions occurring in a surrounding aquifer environment during system operation. The models couple groundwater flow, heat and solute transport together with chemical reactions. In these models, the permeability distribution in space changes with precipitation-dissolution reactions over time. The simulations allowed us to estimate the calcite precipitation rates and porosity variations over space and time as a function of existent hydraulic gradients in an aquifer as well as the intensity of CO2 exchanges with the atmosphere. The results obtained from the numerical model show how CO2 exolution processes that occur during groundwater reinjection into an aquifer and calcite precipitation are related to hydraulic efficiency losses in exploitation systems. Finally, the performance of reinjection wells was evaluated over time according to different scenarios until the systems were fully obstructed. Our simulations also show a reduction in hydraulic conductivity that forces re-injected water to flow downwards, thereby enhancing the dissolution of evaporitic bedrock and producing subsidence that can ultimately result in a dramatic collapse of the injection well infrastructure.

  6. STATUS, CAUSES AND COMBATING SUGGESTIONS OF SANDY DESERTIFICATION IN QINGHAI-TIBET PLATEAU

    Institute of Scientific and Technical Information of China (English)

    LIU Yi-hua; DONG Guang-rong; LI Sen; DONG Yu-xiang

    2005-01-01

    The Qinghai-Tibet Plateau is one of the major sandy desertification regions of China. Based on the recent investigation on sandy desertification, this paper analyses the status such as the type, area, distribution and damage of sandy land desertification in the plateau. Through the analysis on the factors affecting sandy desertification in the region's natural and socio-economic systems as well as the processes and their interrelations, it can be concluded that sandy desertification in the Qinghai-Tibet Plateau resulted from the combined actions of normal natural sand drift processes, natural sandy desertification processes caused by climatic changes and man-made sandy desertification caused by improper human activities. In addition, it also predicts the possible developmental trend including the increase in desertification area and the enhancement in desertification developmental degree with the exacerbation of the complex processes, and finally puts forward some strategic suggestions to combat sandy desertification in the coming years.

  7. 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.

  8. Possible Processes For Acidity And Metal Contaminant Attenuation In A Polluted Estuarine Aquifer

    Science.gov (United States)

    Patrick, E.; Xiaomin, M.; Andrew, B.; Ling, L.; Andrew, B.

    2003-12-01

    Geochemical data obtained from an estuarine sandy aquifer situated below an old industrial landfill (Ayrshire, Scotland) indicated that acidic groundwater (pH acidic plume, elevated concentrations of dissolved heavy metals (Al, Zn, Cu, Cr, Cd) were observed. Water table monitoring and chemical data showed that the groundwater is intruded by estuarine water and is tidally influenced. While geochemical processes associated with acidic plumes and related metal contamination have been widely studied in inland aquifer systems, they have received much less attention in near shore aquifers. Rarely have processes taking place in tidally influenced acidic aquifers been investigated in detail in the field. The aim of the study was to identify the key processes controlling the migration of the acidic plume and reactive transport of contaminants on the path from the aquifer to the estuary. More specifically, the research work has focused on the role played by estuarine water intrusion on the geochemical processes occurring in the aquifer. Through integration of intense geophysical, hydrogeological and hydrogeochemical Investigations, a comprehensive field-monitoring program and laboratory experiments have been carried out. Data obtained were analysed using a geochemical modelling code, PHREEQC-2. In parallel, a model for multi-components reactive transport with density dependent flow was developed and applied to the site. Results from the field, laboratory, and modelling work indicated that oxidation of sulphurous waste located in the landfill at the pollution source is the origin of the groundwater acidity. The low pH plume and associated contaminants are slowly migrating towards the estuary. Retardation of the plume and pH buffering processes are clearly occurring in the aquifer. Ion exchange, precipitation, buffering mineral dissolution, and tidal forcing on the advective-dispersive transport were identified as the main factors influencing contaminant migration and

  9. Investigation on bacterial community and diversity in the multilayer aquifer-aquitard system of the Pearl River Delta, China.

    Science.gov (United States)

    Liu, Kun; Jiao, Jiu Jimmy; Gu, Ji-Dong

    2014-12-01

    Bacteria play an important role in groundwater chemistry. The groundwater resource in the Pearl River Delta (PRD) is responsible for 50 million people's water requirement. High amount of ammonium, arsenic and methane had been reported in groundwater of the PRD, which was considered as the result of intensive bacterial metabolism in the multilayer aquifer-aquitard system. To investigate bacterial community in this system and its relation with groundwater chemistry, sediment and groundwater samples were taken from representative locations in the PRD at different lithological units. Bacterial 16S rRNA gene clone libraries were constructed for microbial identifications and community structures in different strata. Canonical correlation analysis between bacterial linages and environment variables (Cl(-), PO4(3-), SO4(2-), NH4(+)) showed that community structures were significantly modified by geological conditions. Higher bacterial diversity was observed in samples from the Holocene aquitard M1 and aquifer T1, while in the older aquitard M2 and basal aquifer T2, bacterial diversity was much lower. Chloroflexi, γ-proteobacteria and δ-proteobacteria were the dominant phyla in the aquitard sediment. β-proteobacteria was the dominant phylum in sediment which was strongly influenced by fresh water. The results of this study demonstrated that bacterial community contains information of geological events such as sea transgression and deltaic evolution, and microbes in the aquitards have great potential in dominating groundwater quality in aquifers.

  10. Temporal response of hydraulic head, temperature, and chloride concentrations to sea-level changes, Floridan aquifer system, USA

    Science.gov (United States)

    Hughes, J. D.; Vacher, H. L.; Sanford, Ward E.

    2009-06-01

    Three-dimensional density-dependent flow and transport modeling of the Floridan aquifer system, USA shows that current chloride concentrations are not in equilibrium with current sea level and, second, that the geometric configuration of the aquifer has a significant effect on system responses. The modeling shows that hydraulic head equilibrates first, followed by temperatures, and then by chloride concentrations. The model was constructed using a modified version of SUTRA capable of simulating multi-species heat and solute transport, and was compared to pre-development conditions using hydraulic heads, chloride concentrations, and temperatures from 315 observation wells. Three hypothetical, sinusoidal sea-level changes occurring over 100,000 years were used to evaluate how the simulated aquifer responds to sea-level changes. Model results show that hydraulic head responses lag behind sea-level changes only where the Miocene Hawthorn confining unit is thick and represents a significant restriction to flow. Temperatures equilibrate quickly except where the Hawthorn confining unit is thick and the duration of the sea-level event is long (exceeding 30,000 years). Response times for chloride concentrations to equilibrate are shortest near the coastline and where the aquifer is unconfined; in contrast, chloride concentrations do not change significantly over the 100,000-year simulation period where the Hawthorn confining unit is thick.

  11. Using artificial sweeteners to identify contamination sources and infiltration zones in a coupled river-aquifer system

    Science.gov (United States)

    Bichler, Andrea; Muellegger, Christian; Hofmann, Thilo

    2014-05-01

    In shallow or unconfined aquifers the infiltration of contaminated river water might be a major threat to groundwater quality. Thus, the identification of possible contamination sources in coupled surface- and groundwater systems is of paramount importance to ensure water quality. Micropollutants like artificial sweeteners are promising markers for domestic waste water in natural water bodies. Compounds, such as artificial sweeteners, might enter the aquatic environment via discharge of waste water treatment plants, leaky sewer systems or septic tanks and are ubiquitously found in waste water receiving waters. The hereby presented field study aims at the (1) identification of contamination sources and (2) delineation of infiltration zones in a connected river-aquifer system. River bank filtrate in the groundwater body was assessed qualitatively and quantitatively using a combined approach of hydrochemical analysis and artificial sweeteners (acesulfame ACE) as waste water markers. The investigated aquifer lies within a mesoscale alpine head water catchment and is used for drinking water production. It is hypothesized that a large proportion of the groundwater flux originates from bank filtrate of a nearby losing stream. Water sampling campaigns in March and July 2012 confirmed the occurrence of artificial sweeteners at the investigated site. The municipal waste water treatment plant was identified as point-source for ACE in the river network. In the aquifer ACE was present in more than 80% of the monitoring wells. In addition, water samples were classified according to their hydrochemical composition, identifying two predominant types of water in the aquifer: (1) groundwater influenced by bank filtrate and (2) groundwater originating from local recharge. In combination with ACE concentrations a third type of water could be discriminated: (3) groundwater influence by bank filtrate but infiltrated prior to the waste water treatment plant. Moreover, the presence of ACE

  12. Fraction of young water as an indicator of aquifer vulnerability along two regional flow paths in the Mississippi embayment aquifer system, southeastern USA

    Science.gov (United States)

    Kingsbury, James A.; Barlow, Jeannie R. B.; Jurgens, Bryant C.; McMahon, Peter B.; Carmichael, John K.

    2017-09-01

    Wells along two regional flow paths were sampled to characterize changes in water quality and the vulnerability to contamination of the Memphis aquifer across a range of hydrologic and land-use conditions in the southeastern United States. The flow paths begin in the aquifer outcrop area and end at public supply wells in the confined parts of the aquifer at Memphis, Tennessee. Age-date tracer (e.g. SF6, 3H, 14C) data indicate that a component of young water is present in the aquifer at most locations along both flow paths, which is consistent with previous studies at Memphis that documented leakage of shallow water into the Memphis aquifer locally where the overlying confining unit is thin or absent. Mixtures of young and old water were most prevalent where long-term pumping for public supply has lowered groundwater levels and induced downward movement of young water. The occurrence of nitrate, chloride and synthetic organic compounds was correlated to the fraction of young water along the flow paths. Oxic conditions persisted for 10 km or more down dip of the confining unit, and the presence of young water in confined parts of the aquifer suggest that contaminants such as nitrate-N have the potential for transport. Long-term monitoring data for one of the flow-path wells screened in the confined part of the aquifer suggest that the vulnerability of the aquifer as indicated by the fraction of young water is increasing over time.

  13. Aquifer-Circulating Water Curtain Cultivation System To Recover Groundwater Level And Temperature

    Science.gov (United States)

    Kim, Y.; Ko, K.; Chon, C.; Oh, S.

    2011-12-01

    Groundwater temperature, which generally ranges 14 to 16 degree of Celsius all year long, can be said to be 'constant' compared to the amplitude of daily variation of air temperature or surface water. Water curtain cultivating method utilizes this 'constant' groundwater temperature to warm up the inside of greenhouse during winter night by splash groundwater on the roof of inner greenhouse. The area of water curtain cultivation system have increased up to 107.5 square kilometers as of 2006 since when it is first introduced to South Korea in 1984. Groundwater shortage problem became a great issue in a concentrated water curtain cultivation area because the pumped and splashed groundwater is abandoned to nearby stream and natural recharge rate is reduced by greenhouses. The amount of groundwater use for water curtain cultivation system in South Korea is calculated to be 587 million cubic meters which is 35% of national agricultural use of groundwater. A new water curtain cultivation system coupled with aquifer circulating of the splashed groundwater and greenhouse roof-top rainwater harvesting is developed and applied to field site in Nonsan-si, Chungnam province to minimize groundwater shortage problem and recover groundwater level. The aquifer circulating water curtain cultivation system is consist of a pumping well and a injection well of 80 m deep, groundwater transfer and splashing system, recovery tank and rainwater collecting waterway. The distance between injection and pumping well is 15 m and an observation well is installed in the middle of the wells. To characterize hydrogeological properties of this site, hydraulic test such as pumping tests and tracer tests with dye tracer, thermal tracer and ion tracer. Once the integrated system is constructed in this site, hydraulic head in all the wells and temperature of air, recovery tank and groundwater in all the wells are monitored during the operation for 3months in winter season. Hydraulic test and tracer

  14. Occurrence and geochemical behavior of arsenic in a coastal aquifer-aquitard system of the Pearl River Delta, China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ya [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Jiao, Jiu Jimmy, E-mail: jjiao@hku.hk [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Cherry, John A. [School of Engineering, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada)

    2012-06-15

    Elevated concentrations of arsenic, up to 161 {mu}g/L, have been identified in groundwater samples from the confined basal aquifer underlying the aquitard of the Pearl River Delta (PRD). Both aquatic arsenic in pore water and solid arsenic in the sediments in the basal aquifer and aquitard were identified. Arsenic speciation of groundwater in the basal aquifer was elucidated on a pH-Eh diagram. In the PRD, arsenic is enriched in groundwater having both low and high salinity, and arsenic enriched groundwater is devoid of dissolved oxygen, has negative Eh values, is slightly alkaline, and has abnormally high concentrations of ammonium and dissolved organic carbon, but low concentrations of nitrate and nitrite. Results of geochemical and hydrochemical analyses and sequential extraction analysis suggest that reductive dissolution of iron oxyhydroxide could be one of the important processes that mobilized solid arsenic. We speculate that mineralization of sedimentary organic matter could also contribute to aquatic arsenic. Scanning electron microscope analysis confirms that abundant authigenic pyrite is present in the sediments. Sulphate derived from paleo-seawater served as the important sulfur source for authigenic pyrite formation. Co-precipitation of arsenic with authigenic pyrite significantly controlled concentrations of aquatic arsenic in the coastal aquifer-aquitard system. - Highlights: Black-Right-Pointing-Pointer Coastal aquifer and aquitard are treated as an integrate system. Black-Right-Pointing-Pointer Both aquatic arsenic and solid arsenic are observed. Black-Right-Pointing-Pointer Aquatic arsenic is derived from reductive dissolution of iron oxyhydroxide. Black-Right-Pointing-Pointer Aquatic arsenic can also derived from mineralization of sedimentary organic matter. Black-Right-Pointing-Pointer Co-precipitation of arsenic with authigenic pyrite is significant in such a system.

  15. Quantifying Temporal Variations in Water Resources of the Saq Transboundary Aquifer System and Identification of their Controlling Factors

    Science.gov (United States)

    Fallatah, O.; Ahmed, M.; Save, H.; Akanda, A. S.

    2016-12-01

    Abstract: Monthly (April 2002—April 2015) Gravity Recovery and Climate Experiment (GRACE) gravity field solutions, acquired over the Kingdom of Saudi Arabia/Jourdan transboundary aquifer system, the Saq aquifer, were analyzed and spatiotemporally correlated with other relevant land surface models (e.g., GLDAS), remote sensing (e.g., CMAP, NDVI), and field (e.g., water levels) datasets to quantify the temporal variations in the Saq'a water resources and to identify the factors that control these variations. Examination of the GRACE-derived Terrestrial Water Storage (TWS) and Groundwater Storage (GWS) data indicates the following: (1) the Saq aquifer system is witnessing a TWS and GWS depletion rates of -9.05 ± 0.25 mm/yr (-4.84 ± 0.13 km3/yr) and -6.52 ± 0.29 mm/yr (-3.49 ± 0.15 km3/yr), respectively, related to both climatic and anthropogenic factors, (2) the observed TWS depletion rates is partially related to decline in rainfall as evident from comparison of average annual precipitation (AAP) for the investigated period to the previous 23 years (AAP: 1979—2001: 104 mm; 2002—2014: 60 mm), (3) the observed GWS depletion in the Saq aquifer is attributed to groundwater extraction activities for irrigation purposes, and (4) the observed GRACE-derived GWS depletion is highly correlated with the observed water level depletion rates within the investigated wells. Our analysis indicate that the availability of the global monthly GRACE solutions is providing, and will continue to provide, the most practical, informative, and cost-effective tool for monitoring the aquifer systems across the world.

  16. Heterogeneous carbonaceous matter in sedimentary rock lithocomponents causes significant trichloroethylene (TCE) sorption in a low organic carbon content aquifer/aquitard system.

    Science.gov (United States)

    Choung, Sungwook; Zimmerman, Lisa R; Allen-King, Richelle M; Ligouis, Bertrand; Feenstra, Stanley

    2014-10-15

    This study evaluated the effects of heterogeneous thermally altered carbonaceous matter (CM) on trichloroethylene (TCE) sorption for a low fraction organic carbon content (foc) alluvial sedimentary aquifer and aquitard system (foc=0.046-0.105%). The equilibrium TCE sorption isotherms were highly nonlinear with Freundlich exponents of 0.46-0.58. Kerogen+black carbon was the dominant CM fraction extracted from the sediments and accounted for >60% and 99% of the total in the sands and silt, respectively. Organic petrological examination determined that the kerogen included abundant amorphous organic matter (bituminite), likely of marine origin. The dark calcareous siltstone exhibited the greatest TCE sorption among aquifer lithocomponents and accounted for most sorption in the aquifer. The results suggest that the source of the thermally altered CM, which causes nonlinear sorption, was derived from parent Paleozoic marine carbonate rocks that outcrop throughout much of New York State. A synthetic aquifer-aquitard unit system (10% aquitard) was used to illustrate the effect of the observed nonlinear sorption on mass storage potential at equilibrium. The calculation showed that >80% of TCE mass contained in the aquifer was sorbed on the aquifer sediment at aqueous concentration TCE groundwater plume in the aquifer studied. It is implied that sorption may similarly contribute to TCE persistence in other glacial alluvial aquifers with similar geologic characteristics, i.e., comprised of sedimentary rock lithocomponents that contain thermally altered CM.

  17. Heterogeneous carbonaceous matter in sedimentary rock lithocomponents causes significant trichloroethylene (TCE) sorption in a low organic carbon content aquifer/aquitard system

    Science.gov (United States)

    Choung, Sungwook; Zimmerman, Lisa R.; Allen-King, Richelle M.; Ligouis, Bertrand; Feenstra, Stanley

    2014-10-01

    This study evaluated the effects of heterogeneous thermally altered carbonaceous matter (CM) on trichloroethylene (TCE) sorption for a low fraction organic carbon content (foc) alluvial sedimentary aquifer and aquitard system (foc = 0.046-0.105%). The equilibrium TCE sorption isotherms were highly nonlinear with Freundlich exponents of 0.46-0.58. Kerogen + black carbon was the dominant CM fraction extracted from the sediments and accounted for > 60% and 99% of the total in the sands and silt, respectively. Organic petrological examination determined that the kerogen included abundant amorphous organic matter (bituminite), likely of marine origin. The dark calcareous siltstone exhibited the greatest TCE sorption among aquifer lithocomponents and accounted for most sorption in the aquifer. The results suggest that the source of the thermally altered CM, which causes nonlinear sorption, was derived from parent Paleozoic marine carbonate rocks that outcrop throughout much of New York State. A synthetic aquifer-aquitard unit system (10% aquitard) was used to illustrate the effect of the observed nonlinear sorption on mass storage potential at equilibrium. The calculation showed that > 80% of TCE mass contained in the aquifer was sorbed on the aquifer sediment at aqueous concentration < 1000 μg L- 1. These results show that sorption is likely a significant contributor to the persistence of a TCE groundwater plume in the aquifer studied. It is implied that sorption may similarly contribute to TCE persistence in other glacial alluvial aquifers with similar geologic characteristics, i.e., comprised of sedimentary rock lithocomponents that contain thermally altered CM.

  18. The impact of river water intrusion on trace metal cycling in karst aquifers: an example from the Floridan aquifer system at Madison Blue Spring, Florida

    Science.gov (United States)

    Brown, A. L.; Martin, J. B.; Screaton, E.; Spellman, P.; Gulley, J.

    2011-12-01

    Springs located adjacent to rivers can serve as recharge points for aquifers when allogenic runoff increases river stage above the hydraulic head of the spring, forcing river water into the spring vent. Depending on relative compositions of the recharged water and groundwater, the recharged river water could be a source of dissolved trace metals to the aquifer, could mobilize solid phases such as metal oxide coatings, or both. Whether metals are mobilized or precipitated should depend on changes in redox and pH conditions as dissolved oxygen and organic carbon react following intrusion of the river water. To assess how river intrusion events affect metal cycling in springs, we monitored a small recharge event in April 2011 into Madison Blue Spring, which discharges to the Withlacoochee River in north-central Florida. Madison Blue Spring is the entrance to a phreatic cave system that includes over 7.8 km of surveyed conduits. During the event, river stage increased over base flow conditions for approximately 25 days by a maximum of 8%. Intrusion of the river water was monitored with conductivity, temperature and depth sensors that were installed within the cave system and adjacent wells. Decreased specific conductivity within the cave system occurred for approximately 20 days, reflecting the length of time that river water was present in the cave system. During this time, grab samples were collected seven times over a period of 34 days for measurements of major ion and trace metal concentrations at the spring vent and at Martz sink, a karst window connected to the conduit system approximately 150 meters from the spring vent. Relative fractions of surface water and groundwater were estimated based on Cl concentrations of the samples, assuming conservative two end-member mixing during the event. This mixing model indicates that maximum river water contribution to the groundwater system was approximately 20%. River water had concentrations of iron, manganese, and other

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

    Science.gov (United States)

    Ueckert, Martina; Baumann, Thomas

    2017-04-01

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

  20. Setback distances between small biological wastewater treatment systems and drinking water wells against virus contamination in alluvial aquifers.

    Science.gov (United States)

    Blaschke, A P; Derx, J; Zessner, M; Kirnbauer, R; Kavka, G; Strelec, H; Farnleitner, A H; Pang, L

    2016-12-15

    Contamination of groundwater by pathogenic viruses from small biological wastewater treatment system discharges in remote areas is a major concern. To protect drinking water wells against virus contamination, safe setback distances are required between wastewater disposal fields and water supply wells. In this study, setback distances are calculated for alluvial sand and gravel aquifers for different vadose zone and aquifer thicknesses and horizontal groundwater gradients. This study applies to individual households and small settlements (1-20 persons) in decentralized locations without access to receiving surface waters but with the legal obligation of biological wastewater treatment. The calculations are based on Monte Carlo simulations using an analytical model that couples vertical unsaturated and horizontal saturated flow with virus transport. Hydraulic conductivities and water retention curves were selected from reported distribution functions depending on the type of subsurface media. The enteric virus concentration in effluent discharge was calculated based on reported ranges of enteric virus concentration in faeces, virus infectivity, suspension factor, and virus reduction by mechanical-biological wastewater treatment. To meet the risk target of fast-flow alluvial aquifers like coarse gravels, the calculated setback distances were too large to achieve practically. Therefore, for this category of aquifer, a high level of treatment is recommended before the effluent is discharged to the ground surface. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Mendes, Maria Paula; Ribeiro, Luís

    2010-02-01

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

  2. Groundwater availability of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Vaccaro, J.J.; Kahle, S.C.; Ely, D.M.; Burns, E.R.; Snyder, D.T.; Haynes, J.V.; Olsen, T.D.; Welch, W.B.; Morgan, D.S.

    2015-09-22

    The Columbia Plateau Regional Aquifer System (CPRAS) covers about 44,000 square miles of southeastern Washington, northeastern Oregon, and western Idaho. The area supports a $6-billion per year agricultural industry, leading the Nation in production of apples, hops, and eight other commodities. Groundwater pumpage and surface-water diversions supply water to croplands that account for about 5 percent of the Nation’s irrigated lands. Groundwater also is the primary source of drinking water for the more than 1.3 million people in the study area. Increasing competitive demands for water for municipal, fisheries/ecosystems, agricultural, domestic, hydropower, and recreational uses must be met by additional groundwater withdrawals and (or) by changes in the way water resources are allocated and used throughout the hydrologic system. As of 2014, most surface-water resources in the study area were either over allocated or fully appropriated, especially during the dry summer season. In response to continued competition for water, numerous water-management activities and concerns have gained prominence: water conservation, conjunctive use, artificial recharge, hydrologic implications of land-use change, pumpage effects on streamflow, and effects of climate variability and change. An integrated understanding of the hydrologic system is important in order to implement effective water-resource management strategies that address these concerns.

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

    Science.gov (United States)

    Marei, Amer; Schmidt, Natali; Tiehm, Andreas

    2013-04-01

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

  4. Hydrodynamic and salinity evolution of groundwaters during artificial recharge within semi-arid coastal aquifers: A case study of El Khairat aquifer system in Enfidha (Tunisian Sahel)

    Science.gov (United States)

    Ketata, Mouna; Gueddari, Moncef; Bouhlila, Rachida

    2014-09-01

    In common with most coastal aquifers, the El Khairat aquifer suffers the imbalance between recharge and intense exploitation and the extent of agricultural activity. As it is part of the Tunisian Sahel, the Enfidha region has a semiarid climate with very irregular rainfall which makes the groundwater resources quite fragile. This region has major difficulties in managing its water resources which are in decline, especially since, for the last decades, their renewal by rainwater has no longer been sufficient to re-establish the equilibrium. In such a case, the artificial recharge of aquifers by water from dams is a credible alternative to preserve the water resources against marine intrusion and pronounced fall in the piezometric level. The present investigation, based on available data, is aimed to monitoring the piezometry of the El Khairat aquifer during artificial recharge operations (2002-2005) by water from the dam and to identify the impact of the artificial recharge on groundwater quality. The results of this monitoring have shown that the artificial recharge realized between 2002 and 2005, had for effect an increase of the piezometric level of the phreatic aquifer of +0.4 to +2.63 m, especially in the “Ain Garci” zone. The piezometric level of the deep aquifer has also recorded an important increase reaching +3.82 m. After artificial recharge of the aquifer, the spatial distribution of the salinity shows quite low salinity values (lower than 2 g/l) in the western and north-eastern parts of the aquifer, the zone of artificial recharge, whereas the highest ones are found especially in the coastal zones and at the boundaries of the Sebkha where they exceeded 3 g/l. Moreover, we note a slight salinity reduction toward a central zone of the aquifer. Indeed, the zone characterized by salinity lower than 2 g/l and situated near the recharge site becomes more extensive.

  5. Optimization of Design of Aquifer Storage and Recovery System (ASTR) for Enhanced Infiltration Rate with Reduced Cost at the Coastal Aquifers of South-Western Bangladesh

    Science.gov (United States)

    Nawrin, N.; Ahmed, K. M.; Rahman, M. M.

    2016-12-01

    Increasing salinity of natural drinking water sources has been reported as one of the many problems that affect low-income countries. Safe potable water sources in coastal Bangladesh have become contaminated by varying degrees of salinity due to saltwater intrusion, cyclone and storm surges and increased shrimp and crab farming along the coastal areas. This crisis is also exacerbated owing to climate change. The problem of salinity can have serious implications to public health. Here Managed Aquifer Recharge (MAR) has been ascertained as a better solution to overcome the fresh water shortage in the coastal belt of Bangladesh in terms of groundwater quality improvement and supply fresh water even during the dry period. 19 MAR systems have been built and tested in the area for providing community water supply by way of creating freshwater buffer zone in the brackish aquifers through artificial recharge of pond or rooftop rainwater. These existing ASTR schemes consist of sand filtration tank with 4 to 6 large diameter infiltration wells filled with sorted gravel. These larger diameter recharge wells make the construction and maintenance expensive and little difficult for the rural communities. Therefore, modification of design is required for enhancing infiltration rates with reduced costs. As the design of the existing MAR system have confronted some problems, the details of design, construction and performance have been studied from previous investigations and a new modified ASTR scheme has been demonstrated to amplify the infiltration rate along with monitoring scheme. Smaller 4 inch diameter empty recharge wells and PVC screen have been used in the newly developed design. Daily infiltration rate has been increased to 8 to 10 m3/d compared to 4 to 6 m3/d in the old design. Three layered sand filtration tank has been prepared by modification of an abandoned PSF. Time needed for lowering EC to acceptable limits has been found to be significantly lower than the pre

  6. Reducing the predictive uncertainty associated with groundwater management decision-making in the Perth regional aquifer system of Western Australia

    Science.gov (United States)

    Siade, A. J.

    2015-12-01

    The Perth Regional Aquifer Model (PRAMS) framework has been used for about a decade now to evaluate the potential anthropogenic impacts associated with management decisions that affect Perth's groundwater resources. A great wealth of data, expertise and numerical analysis have gone into the development of PRAMS over the years. However, there has been little quantitative work conducted on systemically addressing the uncertainty in the model's structure and predictions. PRAMS is designed to make a variety of regional and local-scale predictions and, both the nature and magnitude of the uncertainty associated with these predictions can vary significantly. A primary prediction to be addressed using the PRAMS framework, will be the effects of various deep-aquifer groundwater management scenarios on both the environmental and social concerns surrounding the superficial aquifer, which supports sensitive wetlands, and the negative impacts of seawater intrusion into the deep aquifers. A particular model-structure component that greatly affects the predictions associated with deep-aquifer groundwater extraction is the characterization of the local fault structure, i.e., whether or not faults are acting as barriers to groundwater flow. Therefore, uncertainty in fault characterization can subsequently lead to significant predictive uncertainty. However, new observation data can be obtained to reduce this uncertainty. In this study, an experimental design methodology is employed to optimally acquire new observations of state in such a way as to maximize the information obtained about the hydraulic properties of faults. Various information criteria are employed to develop optimal locations of new observation wells. The A-optimality criterion was found to be the most effective for comparing sampling strategies given the design assumptions, which include the parameter sets employed, hydraulic forcing, temporal considerations, and the use of the existing observation network. A

  7. Groundwater status and trends for the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Burns, Erick R.; Snyder, Daniel T.; Haynes, Jonathan V.; Waibel, Michael S.

    2012-01-01

    Well information and groundwater-level measurements for the Columbia Plateau Regional Aquifer System in Washington, Oregon, and Idaho, were compiled from data provided by the U.S. Geological Survey and seven other organizations. From the full set of about 60,000 wells and 450,000 water-level measurements a subset of 761 wells within the aquifers of the Columbia River Basalt Group (CRBG) then was used to develop a simple linear groundwater-level trend map for 1968–2009. The mean of the trends was a decline of 1.9 feet per year (ft/yr), with 72 percent of the water levels in wells declining. Rates of declines greater than 1.0 ft/yr were measured in 50 percent of wells, declines greater than 2.0 ft/yr in 38 percent of wells, declines greater than 4.0 ft/yr in 29 percent of wells, and declines greater than 8.0 ft/yr in 4 percent of wells. Water-level data were used to identify groups of wells with similar hydraulic heads and temporal trends to delineate areas of overall similar groundwater conditions. Discontinuities in hydraulic head between well groups were used to help infer the presence of barriers to groundwater flow such as changes in lithology or the occurrence of folds and faults. In areas without flow barriers, dissimilarities in response of well groups over time resulted from the formation of groundwater mounds caused by recharge from irrigation or regions of decline caused by pumping. The areas of focus for this analysis included the Umatilla area, Oregon, and the Palouse Slope/eastern Yakima Fold Belt in the Columbia Basin Ground Water Management Area (GWMA) consisting of Adams, Franklin, Grant, and Lincoln Counties, Washington. In the Umatilla area, water levels from 286 wells were used to identify multiple areas of high hydraulic gradient that indicate vertical and horizontal barriers to groundwater flow. These barriers divide the groundwater-flow system into several compartments with varying degrees of interconnection. Horizontal flow barriers commonly

  8. Hydrogeology - AQUIFERS_UNCONSOLIDATED_USGS_IN: Unconsolidated Aquifer Systems in Indiana (United States Geological Survey, 1:500,000, Polygon Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Five types of unconsolidated aquifers in 12 water-management basins identified by the Indiana Natural Resources Commission (INRC) in Indiana were identified by the...

  9. Development of unconfined conditions in multi-aquifer flow systems: a case study in the Rajshahi Barind, Bangladesh

    Science.gov (United States)

    Rushton, K. R.; Zaman, M. Asaduz

    2016-08-01

    Identifying flow processes in multi-aquifer flow systems is a considerable challenge, especially if substantial abstraction occurs. The Rajshahi Barind groundwater flow system in Bangladesh provides an example of the manner in which flow processes can change with time. At some locations there has been a decrease with time in groundwater heads and also in the magnitude of the seasonal fluctuations. This report describes the important stages in a detailed field and modelling study at a specific location in this groundwater flow system. To understand more about the changing conditions, piezometers were constructed in 2015 at different depths but the same location; water levels in these piezometers indicate the formation of an additional water table. Conceptual models are described which show how conditions have changed between the years 2000 and 2015. Following the formation of the additional water table, the aquifer system is conceptualised as two units. A pumping test is described with data collected during both the pumping and recovery phases. Pumping test data for the Lower Unit are analysed using a computational model with estimates of the aquifer parameters; the model also provided estimates of the quantity of water moving from the ground surface, through the Upper Unit, to provide an input to the Lower Unit. The reasons for the substantial changes in the groundwater heads are identified; monitoring of the recently formed additional water table provides a means of testing whether over-abstraction is occurring.

  10. SIR2012-5282 Surficial Geology: Hydrogeology of the Susquehanna River valley-fill aquifer system and adjacent areas in eastern Broome and southeastern Chenango Counties, New York

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The hydrogeology of the valley-fill aquifer system along a 32-mile reach of the Susquehanna River valley and adjacent areas was evaluated in eastern Broome and...

  11. Three-dimensional hydrogeologic framework for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  12. Selected Basin Characterization Model Parameters for the Great Basin Carbonate and Alluvial Aquifer System of Nevada, Utah, and Parts of Adjacent States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on ground-water resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  13. Geodatabase of the available top and bottom surface datasets that represent the Edwards-Trinity aquifer system, Arkansas, Oklahoma, and Texas

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geodatabase contains the spatial datasets that represent the Edwards-Trinity aquifer system in the States of Arkansas, Oklahoma, and Texas. Included are: (1)...

  14. Geodatabase of the datasets that represent the five vertical subunits of the Coastal Lowlands aquifer system, Alabama, Florida, Louisiana, Mississippi, and Texas

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geodatabase contains spatial datasets that represent the Coastal Lowlands aquifer system in the States of Alabama, Florida, Louisiana, and Texas. Included are:...

  15. Evapotranspiration units in the Basin and Range carbonate-rock aquifer system, White Pine County, Nevada, and adjacent parts of Nevada and Utah

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Accurate estimates of ground-water discharge are crucial in the development of a water budget for the Basin and Range Carbonate-rock Aquifer System (BARCAS) study...

  16. Estimated Altitude of the Top of the Uppermost Unit of Fine-Grained Sediment within the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated altitude of the top of the uppermost fine-grained sediment within the Wood River Valley aquifer system. This map was compiled by...

  17. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Key well sites

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  18. Estimated Altitude of the Consolidated Rock Surface Underlying Quaternary Sediments of the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated altitude of the consolidated rock surface underlying Quaternary sediment of the Wood River Valley aquifer system. This surface is...

  19. Geodatabase of the datasets used to represent the four subunits of the Southeastern Coastal Plain aquifer system, Alabama, Georgia, Mississippi, South Carolina, and Tennessee

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geodatabase includes spatial datasets that represent the Southeastern Coastal Plain aquifer system in the States of Alabama, Georgia, Mississippi, South...

  20. 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

  1. A combined radio- and stable-isotopic study of a California coastal aquifer system

    Science.gov (United States)

    Swarzenski, Peter W.; Baskaran, Mark; Rosenbauer, Robert J.; Edwards, Brian D.; Land, Michael

    2013-01-01

    Stable and radioactive tracers were utilized in concert to characterize geochemical processes in a complex coastal groundwater system and to provide constraints on the kinetics of rock/water interactions. Groundwater samples from wells within the Dominguez Gap region of Los Angeles County, California were analyzed for a suite of major cations (Na+, K+, Mg2+, Ca2+) and anions (Cl−, SO42−), silica, alkalinity, select trace elements (Ba, B, Sr), dissolved oxygen, stable isotopes of hydrogen (δD), oxygen (δ18O), dissolved inorganic carbon (δ13CDIC), and radioactive isotopes (3H, 222Rn and 223,224,226,228Ra). In the study area, groundwater may consist of a complex mixture of native groundwater, intruded seawater, non-native injected water, and oil-field brine water. In some wells, Cl− concentrations attained seawater-like values and in conjunction with isotopically heavier δ18O values, these tracers provide information on the extent of seawater intrusion and/or mixing with oil-field brines. Groundwater 3H above 1 tritium unit (TU) was observed only in a few select wells close to the Dominguez Gap area and most other well groundwater was aged pre-1952. Based on an initial 14C value for the study site of 90 percent modern carbon (pmc), groundwater age estimates likely extend beyond 20 kyr before present and confirm deep circulation of some native groundwater through multiple aquifers. Enriched values of groundwater δ13CDIC in the absence of SO42− imply enhanced anaerobic microbial methanogenesis. While secular equilibrium was observed for 234U/238U (activity ratios ~1) in host matrices, strong isotopic fractionation in these groundwater samples can be used to obtain information of adsorption/desorption kinetics. Calculated Ra residence times are short, and the associated desorption rate constant is about three orders of magnitude slower than that of the adsorption rate constant. Combined stable- and radio-isotopic results provide unique insights into aquifer

  2. A Combined Radio- and Stable-Isotopic Study of a California Coastal Aquifer System

    Directory of Open Access Journals (Sweden)

    Michael Land

    2013-04-01

    Full Text Available Stable and radioactive tracers were utilized in concert to characterize geochemical processes in a complex coastal groundwater system and to provide constraints on the kinetics of rock/water interactions. Groundwater samples from wells within the Dominguez Gap region of Los Angeles County, California were analyzed for a suite of major cations (Na+, K+, Mg2+, Ca2+ and anions (Cl−, SO42−, silica, alkalinity, select trace elements (Ba, B, Sr, dissolved oxygen, stable isotopes of hydrogen (δD, oxygen (δ18O, dissolved inorganic carbon (δ13CDIC, and radioactive isotopes (3H, 222Rn and 223,224,226,228Ra. In the study area, groundwater may consist of a complex mixture of native groundwater, intruded seawater, non-native injected water, and oil-field brine water. In some wells, Cl− concentrations attained seawater-like values and in conjunction with isotopically heavier δ18O values, these tracers provide information on the extent of seawater intrusion and/or mixing with oil-field brines. Groundwater 3H above 1 tritium unit (TU was observed only in a few select wells close to the Dominguez Gap area and most other well groundwater was aged pre-1952. Based on an initial 14C value for the study site of 90 percent modern carbon (pmc, groundwater age estimates likely extend beyond 20 kyr before present and confirm deep circulation of some native groundwater through multiple aquifers. Enriched values of groundwater δ13CDIC in the absence of SO42− imply enhanced anaerobic microbial methanogenesis. While secular equilibrium was observed for 234U/238U (activity ratios ~1 in host matrices, strong isotopic fractionation in these groundwater samples can be used to obtain information of adsorption/desorption kinetics. Calculated Ra residence times are short, and the associated desorption rate constant is about three orders of magnitude slower than that of the adsorption rate constant. Combined stable- and radio-isotopic results provide unique insights

  3. Assessing recharge using remotely sensed data in the Guarani Aquifer System outcrop zone

    Science.gov (United States)

    Lucas, M. C.; Oliveira, P. T. S.; Melo, D. D.; Wendland, E.

    2014-12-01

    Groundwater recharge is an essential hydrology component for sustainable water withdrawal from an aquifer. The Guarani Aquifer System (GAS) is the largest (~1.2 million km2) transboundary groundwater reservoir in South America, supplying freshwater to four countries: Brazil, Argentina, Paraguay and Uruguay. However, recharge in the GAS outcrop zones is one of the least known hydrological variables, in part because studies from hydrological data are scarce or nonexistent. We assess recharge using the water-budget as the difference of precipitation (P) and evapotranspiration (ET). Data is derived from remotely sensed estimates of P (TRMM 3B42 V7) and ET (MOD16) in the Onça Creek watershed over the 2004­-12 period. This is an upland-flat watershed (slope steepness < 1%) dominated by sand soils and representative of the GAS outcrop zones. We compared the remote sensing approach against Water Table Fluctuation (WTF) method and another water-budget using ground-based measurements. Uncertainty propagation analysis were also performed. On monthly basis, TRMM P exhibited a great agreement with ground-based P data (R2 = 0.86 and RMSE = 41 mm). Historical (2004-12) mean(±sd) satellite-based recharge (Rsat) was 537(±224) mm y-1, while ground-based recharge using water-budget (Rgr) and WTF (Rwtf) method was 469 mm y-1 and 311(±150) mm y-1, respectively. We found that ~440 mm y-1 is a reasonable historical mean (between Rsat, Rgr and Rwtf) recharge for the study area over 2004-2012 period. The latter mean recharge estimate is about 29% of the mean historical P (1,514 mm y-1). Our results provide the first insight about an intercomparison of water budget from remote sensing and measured data to estimate recharge in the GAS outcrop zone. These results should be useful for future studies on assessing recharge in the GAS outcrop zones. Since accurate and precise recharge estimation still is a gap, our recharge satellite-based is considered acceptable for the Onça Creek

  4. The Tunisian Jurassic aquifer in the North African Sahara aquifer system: information derived from two-dimensional seismic reflection and well logs

    Science.gov (United States)

    Ben Lasmar, Rafika; Guellala, Rihab; Garrach, Mohamed; Mahroug, Ali; Sarsar Naouali, Benen; Inoubli, Mohamed Hédi

    2017-07-01

    Southern Tunisia is an arid area where socio-economic activities are dependent on groundwater resources. The presented study aims to better characterize the Jurassic aquifer based on geological and geophysical data, with a view to develop a rational exploitation program. Well logs are used to precisely determine the position and composition of the known Jurassic aquifer layers and to identify others able to produce good quality water. The logs show that limestones, sandstones and dolomites of the Krachoua, Techout and Foum Tataouine formations are the main Jurassic aquifers. Sixty-eight seismic-reflection sections are integrated within this study. The interpolation between the interpreted sections leads to the construction of isochronous isopach maps and geoseismic sections, and their analysis finds that compressive and extensive tectonic deformations have influenced the Jurassic aquifer geometry. The Hercynian orogeny phase manifestation is remarkable in that there are several stratigraphic gaps in the Jurassic sequence. The E-W, NW-SE, and NNW-SSE accidents, reactivated in normal faults since the Permian to Lower Cretaceous epochs, have generated the structures found in the Jurassic series, such as subsided and raised blocks. Their syn-sedimentary activity has controlled the thickness and facies of these series. The Cretaceous, Tortonian and Post-Villafranchian compressions are responsible for the Jurassic-deposits folding in some localities. The highlighted tectonic and sedimentary events have an important impact on the Jurassic aquifer function by favoring the Jurassic aquifer interconnections and their connections with the Triassic and Cretaceous permeable series.

  5. Hydrochemical characterization and pollution sources identification of groundwater in Salawusu aquifer system of Ordos Basin, China.

    Science.gov (United States)

    Yang, Qingchun; Wang, Luchen; Ma, Hongyun; Yu, Kun; Martín, Jordi Delgado

    2016-09-01

    Ordos Basin is located in an arid and semi-arid region of northwestern China, which is the most important energy source bases in China. Salawusu Formation (Q3 s) is one of the most important aquifer systems of Ordos Basin, which is adjacent to Jurassic coalfield areas. A large-scale exploitation of Jurassic coal resources over ten years results in series of influences to the coal minerals, such as exposed to the oxidation process and dissolution into the groundwater due to the precipitation infiltration. Therefore, how these processes impact groundwater quality is of great concerns. In this paper, the descriptive statistical method, Piper trilinear diagram, ratios of major ions and canonical correspondence analysis are employed to investigate the hydrochemical evolution, determine the possible sources of pollution processes, and assess the controls on groundwater compositions using the monitored data in 2004 and 2014 (before and after large-scale coal mining). Results showed that long-term exploration of coal resources do not result in serious groundwater pollution. The hydrochemical types changed from HCO3(-)-CO3(2-) facies to SO4(2-)-Cl facies during 10 years. Groundwater hardness, nitrate and sulfate pollution were identified in 2014, which was most likely caused by agricultural activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Hindcast of water availability in regional aquifer systems using MODFLOW Farm Process

    Science.gov (United States)

    Schmid, Wolfgang; Hanson, Randall T.; Faunt, Claudia C.; Phillips, Steven P.

    2015-01-01

    Coupled groundwater and surface-water components of the hydrologic cycle can be simulated by the Farm Process for MODFLOW (MF-FMP) in both irrigated and non-irrigated areas and aquifer-storage and recovery systems. MF-FMP is being applied to three productive agricultural regions of different scale in the State of California, USA, to assess the availability of water and the impacts of alternative management decisions. Hindcast simulations are conducted for similar periods from the 1960s to near recent times. Historical groundwater pumpage is mostly unknown in one region (Central Valley) and is estimated by MF-FMP. In another region (Pajaro Valley), recorded pumpage is used to calibrate model-estimated pumpage. Multiple types of observations are used to estimate uncertain parameters, such as hydraulic, land-use, and farm properties. MF-FMP simulates how climate variability and water-import availability affect water demand and supply. MF-FMP can be used to predict water availability based on anticipated changes in anthropogenic or natural water demands. Keywords groundwater; surface-water; irrigation; water availability; response to climate variability/change

  7. Thousands of microbial genomes shed light on interconnected biogeochemical processes in an aquifer system.

    Science.gov (United States)

    Anantharaman, Karthik; Brown, Christopher T; Hug, Laura A; Sharon, Itai; Castelle, Cindy J; Probst, Alexander J; Thomas, Brian C; Singh, Andrea; Wilkins, Michael J; Karaoz, Ulas; Brodie, Eoin L; Williams, Kenneth H; Hubbard, Susan S; Banfield, Jillian F

    2016-10-24

    The subterranean world hosts up to one-fifth of all biomass, including microbial communities that drive transformations central to Earth's biogeochemical cycles. However, little is known about how complex microbial communities in such environments are structured, and how inter-organism interactions shape ecosystem function. Here we apply terabase-scale cultivation-independent metagenomics to aquifer sediments and groundwater, and reconstruct 2,540 draft-quality, near-complete and complete strain-resolved genomes that represent the majority of known bacterial phyla as well as 47 newly discovered phylum-level lineages. Metabolic analyses spanning this vast phylogenetic diversity and representing up to 36% of organisms detected in the system are used to document the distribution of pathways in coexisting organisms. Consistent with prior findings indicating metabolic handoffs in simple consortia, we find that few organisms within the community can conduct multiple sequential redox transformations. As environmental conditions change, different assemblages of organisms are selected for, altering linkages among the major biogeochemical cycles.

  8. Geochemical modeling of groundwater evolution in a volcanic aquifer system of Kumamoto area, Japan

    Science.gov (United States)

    Hossain, S.; Hosono, T.; Ide, K.; Shimada, J.

    2013-12-01

    Inverse geochemical modeling (PHREEQC) was used to identify the evolution of groundwater in a volcanic aquifer system of Kumamoto area (103 Km2) in southern Japan. The modeling was based on flow paths proposed by different researcher using different techniques, and detailed chemical analysis of groundwater along the flow paths. Potential phases were constrained using general trends in hydrochemical data of groundwater, mineralogical data, and saturation indices data of minerals in groundwater. Hydrochemical data from a total of 180 spring, river and well water samples were used to evaluate water quality and to determine processes that control groundwater chemistry. The samples from the area were classified as recharge zone water (Ca-HCO3 and Ca-SO4 type), lateral flow to discharge zone water (Ca-HCO3 and Na-HCO3 type) and stagnant zone water (Na-Cl type). The inverse geochemical modeling demonstrated that relatively few phases are required to derive water chemistry in the area. The downstream changes in groundwater chemistry could be largely explained by the weathering of plagioclase to kaolinite, with possible contributions from weathering of biotite and pyroxene. In a broad sense, the reactions responsible for the hydrochemical evolution in the area fall into three categories (1) silicate weathering reactions (2) precipitation of amorphous silica and clay minerals and (3) Cation exchange reactions of Ca2+ to Na+.

  9. Ground-Water Availability Assessment for the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    ,

    2008-01-01

    The U.S. Geological Survey (USGS) is assessing the availability and use of the Nation's water resources to gain a clearer understanding of the status of our water resources and the land-use, water-use, and climatic trends that affect them. The goal of the National assessment is to improve our ability to forecast water availability for future economic and environmental uses. Assessments will be completed for regional aquifer systems across the Nation to help characterize how much water we have now, how water availability is changing, and how much water we can expect to have in the future (Reilly and others, 2008). Water availability is a function of many factors, including the quantity and quality of water, and the laws, regulations, economics, and environmental factors that control its use. The focus of the Columbia Plateau regional ground-water availability assessment is to improve fundamental knowledge of the ground-water balance of the region, including the flows, storage, and ground-water use by humans. An improved quantitative understanding of the region's water balance not only provides key information about water quantity, but also can serve as a fundamental basis for many analyses of water quality and ecosystem health.

  10. Estimation of nitrogen pools in irrigated potato production on sandy soil using the model SUBSTOR.

    Directory of Open Access Journals (Sweden)

    Rishi Prasad

    Full Text Available Recent increases in nitrate concentrations in the Suwannee River and associated springs in northern Florida have raised concerns over the contributions of non-point sources. The Middle Suwannee River Basin (MSRB is of special concern because of prevalent karst topography, unconfined aquifers and sandy soils which increase vulnerability of the ground water contamination from agricultural operations--a billion dollar industry in this region. Potato (Solanum tuberosum L. production poses a challenge in the area due to the shallow root system of potato plants, and low water and nutrient holding capacity of the sandy soils. A four-year monitoring study for potato production on sandy soil was conducted on a commercial farm located in the MSRB to identify major nitrogen (N loss pathways and determine their contribution to the total environmental N load, using a partial N budget approach and the potato model SUBSTOR. Model simulated environmental N loading rates were found to lie within one standard deviation of the observed values and identified leaching loss of N as the major sink representing 25 to 38% (or 85 to 138 kg ha(-1 N of the total input N (310 to 349 kg ha(-1 N. The crop residues left in the field after tuber harvest represented a significant amount of N (64 to 110 kg ha(-1 N and posed potential for indirect leaching loss of N upon their mineralization and the absence of subsequent cover crops. Typically, two months of fallow period exits between harvest of tubers and planting of the fall row crop (silage corn. The fallow period is characterized by summer rains which pose a threat to N released from rapidly mineralizing potato vines. Strategies to reduce N loading into the groundwater from potato production must focus on development and adoption of best management practices aimed on reducing direct as well as indirect N leaching losses.

  11. The quality of our Nation's waters: water quality in the Northern Atlantic Coastal Plain surficial aquifer system, Delaware, Maryland, New Jersey, New York, North Carolina, and Virginia, 1988-2009

    Science.gov (United States)

    Denver, Judith M.; Ator, Scott W.; Fischer, Jeffrey M.; Harned, Douglas C.; Schubert, Christopher E.; Szabo, Zoltan

    2015-01-01

    The surficial aquifer system of the Northern Atlantic Coastal Plain is made up of unconfined aquifers that underlie most of the area. This aquifer system is a critical renewable source of drinking water and is the source of most flow to streams and of recharge to underlying confined aquifers. Millions of people rely on the surficial aquifer system for public and domestic water supply, in particular in the densely populated areas of Long Island, New York, and in southern New Jersey, but also in more rural areas. Because the aquifer sediments are permeable and the water table is shallow, the surficial aquifer system is vulnerable to contamination from chemicals that are applied to the land surface and carried into groundwater with infiltrating rainfall and snowfall.

  12. Organic and inorganic carbon dynamics in a karst aquifer: Santa Fe River Sink-Rise system, north Florida, USA

    Science.gov (United States)

    Jin, Jin; Zimmerman, Andrew R.; Moore, Paul J.; Martin, Jonathan B.

    2014-03-01

    Spatiotemporal variations in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), major ions concentrations and other geochemical parameters including stable carbon isotopes of DIC (δ13CDIC), were measured in surface water and deep and shallow well water samples of the Santa Fe River Sink-Rise eogenetic karst system, north Florida, USA. Three end-member water sources were identified: one DOC-rich/DIC-poor/δ13CDIC-depleted, one DOC-poor/DIC-rich/δ13CDIC-enriched, and one enriched in major ions. Given their spatiotemporal distributions, they were presumed to represent soil water, upper aquifer groundwater, and deep aquifer water sources, respectively. Using assumed ratios of Na+, Cl, and SO42- for each end-member, a mixing model calculated the contribution of each water source to each sample. Then, chemical effects of biogeochemical reactions were calculated as the difference between those predicted by the mixing model and measured species concentrations. In general, carbonate mineral dissolution occurred throughout the Sink-Rise system, surface waters were net autotrophic and the subsurface was in metabolic balance, i.e., no net DOC or DIC production or consumption. However, there was evidence for chemolithoautotrophy, perhaps by hydrogen oxidizing microbes, at some deep aquifer sites. Mineralization of this autochthonous natural dissolved organic matter (NDOM) led to localized carbonate dissolution as did surface water-derived NDOM supplied to shallow well sites during the highest flow periods. This study demonstrates linkages between hydrology, abiotic and microbial processes and carbon dynamics and has important implications for groundwater quality, karst morphologic evolution, and hydrogeologic projects such as aquifer storage and recovery in karst systems.

  13. Relative Recovery of Thermal Energy and Fresh Water in Aquifer Storage and Recovery Systems.

    Science.gov (United States)

    Miotliński, K; Dillon, P J

    2015-01-01

    This paper explores the relationship between thermal energy and fresh water recoveries from an aquifer storage recovery (ASR) well in a brackish confined aquifer. It reveals the spatial and temporal distributions of temperature and conservative solutes between injected and recovered water. The evaluation is based on a review of processes affecting heat and solute transport in a homogeneous aquifer. In this simplified analysis, it is assumed that the aquifer is sufficiently anisotropic to inhibit density-affected flow, flow is axisymmetric, and the analysis is limited to a single ASR cycle. Results show that the radial extent of fresh water at the end of injection is greater than that of the temperature change due to the heating or cooling of the geological matrix as well as the interstitial water. While solutes progress only marginally into low permeability aquitards by diffusion, conduction of heat into aquitards above and below is more substantial. Consequently, the heat recovery is less than the solute recovery when the volume of the recovered water is lower than the injection volume. When the full volume of injected water is recovered the temperature mixing ratio divided by the solute mixing ratio for recovered water ranges from 0.95 to 0.6 for ratios of maximum plume radius to aquifer thickness of 0.6 to 4.6. This work is intended to assist conceptual design for dual use of ASR for conjunctive storage of water and thermal energy to maximize the potential benefits.

  14. Norovirus outbreak caused by a new septic system in a dolomite aquifer.

    Science.gov (United States)

    Borchardt, Mark A; Bradbury, Kenneth R; Alexander, E Calvin; Kolberg, Rhonda J; Alexander, Scott C; Archer, John R; Braatz, Laurel A; Forest, Brian M; Green, Jeffrey A; Spencer, Susan K

    2011-01-01

    Septic systems that are built in compliance with regulations are generally not expected to be the cause of groundwater borne disease outbreaks, especially in areas with thick vadose zones. However, this case study demonstrates that a disease outbreak can occur in such a setting and outlines the combination of epidemiological, microbiological, and hydrogeological methods used to confirm the source of the outbreak. In early June 2007, 229 patrons and employees of a new restaurant in northeastern Wisconsin were affected by acute gastroenteritis; 6 people were hospitalized. Epidemiological case-control analysis indicated that drinking the restaurant's well water was associated with illness (odds ratio = 3.2, 95% confidence interval = 0.9 to 11.4, P = 0.06). Microbiological analysis (quantitative reverse transcription-polymerase chain reaction) measured 50 genomic copies per liter of norovirus genogroup I in the well water. Nucleotide sequencing determined the genotype as GI.2 and further showed the identical virus was present in patrons' stool specimens and in the septic tank. Tracer tests using dyes injected at two points in the septic system showed that effluent was traveling from the tanks (through a leaking fitting) and infiltration field to the well in 6 and 15 d, respectively. The restaurant septic system and well (85-m deep, in a fractured dolomite aquifer) both conformed to state building codes. The early arrival of dye in the well, which was 188 m from the septic field and located beneath a 35-m thick vadose zone, demonstrates that in highly vulnerable hydrogeological settings, compliance with regulations may not provide adequate protection from fecal pathogens.

  15. The University of Minnesota aquifer thermal energy storage (ATES) field test facility -- system description, aquifer characterization, and results of short-term test cycles

    Energy Technology Data Exchange (ETDEWEB)

    Walton, M.; Hoyer, M.C.; Eisenreich, S.J.; Holm, N.L.; Holm, T.R.; Kanivetsky, R.; Jirsa, M.A.; Lee, H.C.; Lauer, J.L.; Miller, R.T.; Norton, J.L.; Runke, H. (Minnesota Geological Survey, St. Paul, MN (United States))

    1991-06-01

    Phase 1 of the Aquifer Thermal Energy Storage (ATES) Project at the University of Minnesota was to test the feasibility, and model, the ATES concept at temperatures above 100{degrees}C using a confined aquifer for the storage and recovery of hot water. Phase 1 included design, construction, and operation of a 5-MW thermal input/output field test facility (FTF) for four short-term ATES cycles (8 days each of heat injection, storage, and heat recover). Phase 1 was conducted from May 1980 to December 1983. This report describes the FTF, the Franconia-Ironton-Galesville (FIG) aquifer used for the test, and the four short-term ATES cycles. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic effects are all included. The FTF consists of monitoring wells and the source and storage well doublet completed in the FIG aquifer with heat exchangers and a fixed-bed precipitator between the wells of the doublet. The FIG aquifer is highly layered and a really anisotropic. The upper Franconia and Ironton-Galesville parts of the aquifer, those parts screened, have hydraulic conductivities of {approximately}0.6 and {approximately}1.0 m/d, respectively. Primary ions in the ambient ground water are calcium and magnesium bicarbonate. Ambient temperature FIG ground water is saturated with respect to calcium/magnesium bicarbonate. Heating the ground water caused most of the dissolved calcium to precipitate out as calcium carbonate in the heat exchanger and precipitator. Silica, calcium, and magnesium were significantly higher in recovered water than in injected water, suggesting dissolution of some constituents of the aquifer during the cycles. Further work on the ground water chemistry is required to understand water-rock interactions.

  16. 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...

  17. Behavior and Fate of PFOA and PFOS in Sandy Aquifer ...

    Science.gov (United States)

    Microcosms were constructed with sediment from beneath a landfill that received waste containing PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate). The microcosms were amended with PFOA and PFOS, and sampled after 91, 210, 343, 463, 574, and 740 days of incubation. After 740 days, selected microcosms were extracted to determine the mass of PFOA and PFOS remaining. There was no evidence for degradation of PFOA or PFOS. Over time, the aqueous concentrations of PFOA and PFOS increased in the microcosms, indicating that PFOA and PFOS that had originally sorbed to the sediment was desorbing. At the beginning of the experiment, the adsorption coefficient, Kd, averaged 0.27 L/kg for PFOA and 1.2 L/kg for PFOS. After 740 days of incubation, sorption of PFOA was not detectable and the Kd of PFOS was undetectable in two microcosms and was 0.08 L/kg in a third microcosm. During incubation, the pH of the pore water in the microcosms increased from pH 7.2 to pH ranging from 8.1 to 8.8 and the zeta potential of the sediment decreased with increasing pH. These observations suggest sorption of PFOA and PFOS was controlled by electrostatic sorption on ferric oxide minerals, and not by sorption to organic carbon. These observations suggest sorption of PFOA and PFOS was controlled by electrostatic sorption on ferric oxide minerals, and not by sorption to organic carbon.

  18. Fate of herbicides in deep subsurface limestone and sandy aquifers

    DEFF Research Database (Denmark)

    Janniche, Gry Sander

    afgørende for at vurdere herbiciders skæbne i underjord og grundvandsmagasiner. PhD-projektet har undersøgt sorption og nedbrydning af fire model-herbicider (atrazin, acetochlor, mecoprop og isoproturon) i kalksten og sandede grundvands¬magasiner. Desuden er den rumlige småskala-variation af herbicidernes...... tydelig selv inden for få cm afstand over dybden, og betydningen af denne variation afhænger af den samlede udbredelse af lag med forhøjet sorption eller nedbrydning; 2) at kalk/kalksten yder ringe beskyttelse mod grundvands¬forurening med mecoprop, atrazin, isoproturon og acetochlor, da sorptionen er lav...... og mineraliseringen meget langsom for isoproturon, acetochlor og mecoprop, og atrazin ikke er nedbrydeligt; 3) at i sandede grundvands¬magasiner er sorptionen af de fire herbicider generelt lav, men kan under reducerede forhold være kraftig for især isoproturon og acetochlor. Mecoprop, isoproturon og...

  19. Occurrence of Radium-224, Radium-226 and Radium-228 in Water from the Vincentown and Wenonah-Mount Laurel Aquifers, the Englishtown Aquifer System, and the Hornerstown and Red Bank Sands, Southwestern and South-Central New Jersey

    Science.gov (United States)

    dePaul, Vincent T.; Szabo, Zoltan

    2007-01-01

    This investigation is the first regionally focused study of the presence of natural radioactivity in water from the Vincentown and Wenonah-Mount Laurel aquifers, Englishtown aquifer system, and the Hornerstown and Red Bank Sands. Geologic materials composing the Vincentown and Wenonah-Mount Laurel aquifers and the Hornerstown and Red Bank Sands previously have been reported to contain radioactive (uranium-enriched) phosphatic strata, which is common in deposits from some moderate-depth coastal marine environments. The decay of uranium and thorium gives rise to natural radioactivity and numerous radioactive progeny, including isotopes of radium. Naturally occurring radioactive isotopes, especially those of radium, are of concern because radium is a known human carcinogen and ingestion (especially in water used for drinking) can present appreciable health risks. A regional network in southwestern and south-central New Jersey of 39 wells completed in the Vincentown and Wenonah-Mount Laurel aquifers, the Englishtown aquifer system, and the Hornerstown and Red Bank Sands was sampled for determination of gross alpha-particle activity; concentrations of radium radionuclides, major ions, and selected trace elements; and physical properties. Concentrations of radium-224, radium-226, and radium-228 were determined for water from 28 of the 39 wells, whereas gross alpha-particle activity was determined for all 39. The alpha spectroscopic technique was used to determine concentrations of radium-224, which ranged from less than 0.5 to 2.7 pCi/L with a median concentration of less than 0.5pCi/L, and of radium-226, which ranged from less than 0.5 to 3.2 pCi/L with a median concentration of less than 0.5 pCi/L. The beta-counting technique was used to determine concentrations of radium-228. The concentration of radium-228 ranged from less than 0.5 to 4.3 pCi/L with a median of less than 0.5. Radium-228, when quantifiable, had the greatest concentration of the three radium

  20. Dissolved Organic Carbon Influences Microbial Community Composition and Diversity in Managed Aquifer Recharge Systems

    KAUST Repository

    Li, D.

    2012-07-13

    This study explores microbial community structure in managed aquifer recharge (MAR) systems across both laboratory and field scales. Two field sites, the Taif River (Taif, Saudi Arabia) and South Platte River (Colorado), were selected as geographically distinct MAR systems. Samples derived from unsaturated riverbed, saturated-shallow-infiltration (depth, 1 to 2 cm), and intermediate-infiltration (depth, 10 to 50 cm) zones were collected. Complementary laboratory-scale sediment columns representing low (0.6 mg/liter) and moderate (5 mg/liter) dissolved organic carbon (DOC) concentrations were used to further query the influence of DOC and depth on microbial assemblages. Microbial density was positively correlated with the DOC concentration, while diversity was negatively correlated at both the laboratory and field scales. Microbial communities derived from analogous sampling zones in each river were not phylogenetically significantly different on phylum, class, genus, and species levels, as determined by 16S rRNA gene pyrosequencing, suggesting that geography and season exerted less sway than aqueous geochemical properties. When field-scale communities derived from the Taif and South Platte River sediments were grouped together, principal coordinate analysis revealed distinct clusters with regard to the three sample zones (unsaturated, shallow, and intermediate saturated) and, further, with respect to DOC concentration. An analogous trend as a function of depth and corresponding DOC loss was observed in column studies. Canonical correspondence analysis suggests that microbial classes Betaproteobacteria and Gammaproteobacteria are positively correlated with DOC concentration. Our combined analyses at both the laboratory and field scales suggest that DOC may exert a strong influence on microbial community composition and diversity in MAR saturated zones.

  1. Study on Volume Strain Inversion from Water Level Change of Well-aquifer Systems

    Institute of Scientific and Technical Information of China (English)

    Yan Rui; Gao Fuwang; Chen Yong

    2008-01-01

    Based on linear poroelastic and hydrogcology theory, a mathematical expression describing the relationship between water level change and aquifer volume strain is put forward. Combined with earth tidal theory, we analyze the response characteristics from well-aquifer water level change to earth tide of volume strain and present a method of volume strain inversion from water level change. Comparing the results of inversion with real observed data, we found that there is a good consistency. This suggcsts that the method of volume strain inversion from water level change is proper. It will offer a reference for learning about hydrogeology characteristics, volume strain and searching for precursor anomalies.

  2. Sustainability of Intensively Exploited Aquifer Systems in the North China Plain:Insights from Multiple Environmental Tracers

    Institute of Scientific and Technical Information of China (English)

    Aina Su; Zongyu Chen; Jun Liu; Wen Wei

    2014-01-01

    Environmental tracers are proving to be a unique tool for assessing groundwater sustaina-bility, such as characterization of recharge, identification of pathways and sources of contaminants, and prediction of groundwater change in response to excessive abstraction. This paper helps to better under-stand the groundwater sustainability in the Quaternary aquifer from the tracer data in the North China Plain. Relatively modern ground waters occur in the piedmont plain with 3H-3He age less than 40 a with-in a depth 100 m. These ground waters are mainly recharged from the local precipitation and irrigation return. The recharge rate estimated by tracers is in the range of 0.24 to 0.32 m/a. Paleowater which is dated from 10 000 a B.P. to more than 35 000 a B.P. by radiocarbon dating is found in highly-confined portions of Quaternary aquifer systems. This indicates that water recharge took place during the past glacial period. The tracers have suggested a slow natural replenishment rates to the central plain. The aquifer has been overexploited currently. Some strategies that can be implemented to promote a sustain-able groundwater supply are needed to implement in future.

  3. Chloride as tracer of solute transport in the aquifer-aquitard system in the Pearl River Delta, China

    Science.gov (United States)

    Kuang, Xingxing; Jiao, Jiu Jimmy; Wang, Ya

    2016-08-01

    A 1D numerical model is constructed to investigate the impact of sedimentation and sea level changes on transport of Cl- in the aquifer-aquitard system in the Pearl River Delta (PRD), China. The model simulates the evolution of the vertical Cl- concentration profiles during the Holocene. Sedimentation is modeled as a moving boundary problem. Chloride concentration profiles are reconstructed for nine boreholes, covering a wide area of the PRD, from northwest to southeast. Satisfactory agreement is obtained between simulated and measured Cl- concentration profiles. Diffusion solely is adequate to reproduce the vertical Cl- concentration profiles, which indicates that diffusion is the regionally dominant vertical transport mechanism across the aquitards in the PRD. The estimated effective diffusion coefficients of the aquitards range from 2.0 × 10-11 to 2.0 × 10-10 m2/s. The effective diffusion coefficients of the aquifers range from 3.0 × 10-11 to 4.0 × 10-10 m2/s. Advective transport tends to underestimate Cl- concentrations in the aquitard and overestimate Cl- concentrations in the basal aquifer. The results of this study will help understand the mechanisms of solute transport in the PRD and other deltas with similar geological and hydrogeological characteristics.

  4. Deducing transmissivity from specific capacity in the heterogeneous upper aquifer system of Jifarah Plain, NW-Libya

    Science.gov (United States)

    Al Farrah, Nawal; Van Camp, Marc; Walraevens, Kristine

    2013-09-01

    The hydraulic characterisation of aquifer systems is important for the development of exploitation scenarios and management strategies. Especially in lithologically heterogeneous aquifers, local scale variations in transmissivity (T) may not be neglected. Field scale transmissivity values are usually derived from pumping tests, but in most cases their number and availability is rather limited. Therefore T values are often estimated from specific well capacities (SC) which can easily be measured in exploitation wells based on static and dynamic water levels. Empirical relations allow T to be calculated from SC values using a power law relation of the form T = A * SCN. In this paper this relation is investigated for three aquifers in north-west Lybia, using the results from step-drawdown tests which allow determination of well efficiencies, which can be incorporated into the regression analysis. The obtained fitting coefficients of the power law relations were compared with published values from other studies. Both parameters of the power law relation (scale factor and power coefficient) seem to be highly correlated following an exponential relationship (R2 = 0.89), reducing the T-SC relation to a single parameter equation, which is mainly related to lithology.

  5. Nitrate leaching from sandy loam soils under a double-cropping forage system estimated from suction-probe measurements.

    NARCIS (Netherlands)

    Trindade, H.; Coutinho, J.; Beusichem, van M.L.; Scholefield, D.; Moreira, N.

    1997-01-01

    Nitrate leaching from a double-cropping forage system was measured over a 2-year period (June 1994–May 1996) in the Northwest region of Portugal using ceramic cup samplers. The crops were grown for silage making and include maize (from May to September) and a winter crop (rest of the year)

  6. Conjunctive Management of Multi-Aquifer System for Saltwater Intrusion Mitigation

    Science.gov (United States)

    Tsai, F. T. C.; Pham, H. V.

    2015-12-01

    Due to excessive groundwater withdrawals, many water wells in Baton Rouge, Louisiana experience undesirable chloride concentration because of saltwater intrusion. The study goal is to develop a conjunctive management framework that takes advantage of the Baton Rouge multi-aquifer system to mitigate saltwater intrusion. The conjunctive management framework utilizes several hydraulic control techniques to mitigate saltwater encroachment. These hydraulic control approaches include pumping well relocation, freshwater injection, saltwater scavenging, and their combinations. Specific objectives of the study are: (1) constructing scientific geologic architectures of the "800-foot" sand, the "1,000-foot" sand, the "1,200-foot" sand, the "1,500-foot" sand, the "1,700-foot" sand, and the "2,000-foot" sand, (2) developing scientific saltwater intrusion models for these sands. (3) using connector wells to draw native groundwater from one sand and inject to another sand to create hydraulic barriers to halt saltwater intrusion, (4) using scavenger wells or well couples to impede saltwater intrusion progress and reduce chloride concentration in pumping wells, and (5) reducing cones of depression by relocating and dispersing pumping wells to different sands. The study utilizes optimization techniques and newest LSU high performance computing (HPC) facilities to derive solutions. The conjunctive management framework serves as a scientific tool to assist policy makers to solve the urgent saltwater encroachment issue in the Baton Rouge area. The research results will help water companies as well as industries in East Baton Rouge Parish and neighboring parishes by reducing their saltwater intrusion threats, which in turn would sustain Capital Area economic development.

  7. Chemical characteristics of water in the surficial aquifer system, Broward County, Florida

    Science.gov (United States)

    Howie, Barbara

    1987-01-01

    Water quality data was collected in 1981 and 1982 during the drilling of test holes at 27 sites throughout Broward County, Florida. Determinations were made for the following physical properties and chemical constituents: pH, alkalinity, specific conductance, major ions, selected nutrients and dissolved iron, aluminum, and manganese. Determinations for the trace elements-arsenic, barium, cadmium, chromium, lead, zinc, selenium, and mercury-were made at 14 wells. Water in the surficial aquifer system between the coastal ridge and the conservation areas is potable and usually is a calcium bicarbonate type for the first 140 ft or more below land surface. Between depths of 140 and 230 ft, groundwater generally grades into a mixed-ion water type. In some areas, diluted seawater occurs beneath the mixed water zone. Dissolved iron concentrations between the coastal ridge and the conservation areas are variable but generally exceed 1,000 micrograms/L. Beneath the conservation areas and the western edge of Broward County, groundwater in the first 100 ft below land surface generally is either a calcium bicarbonate type or a mixed-ion type. At depths between 100 and 200 ft, diluted residual seawater occurs, except along the far western edge of the county. Residual seawater is least diluted in the north. Dissolved iron concentrations generally are between 300 and 1 ,000 micrograms/L but increase to the east of the conservation areas. Other findings of the investigation include: (1) groundwater in some areas west of the coastal ridge probably would be suitable for most domestic, agricultural, and industrial uses if it were treated for carbonate hardness; (2) groundwater in much of Broward County is chemically altered by natural softening and magnesium enrichment (natural softening increases to the west and is very pronounced beneath the far western edge of the county); and (3) there is evidence of mineralized water from the conservation areas mixing with groundwater east of the

  8. 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

    2017-07-01

    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.

  9. Application of groundwater residence time tracers and broad screening for micro-organic contaminants in the Indo-Gangetic aquifer system

    Science.gov (United States)

    Lapworth, Dan; Das, Prerona; Mukherjee, Abhijit; Petersen, Jade; Gooddy, Daren; Krishan, Gopal

    2017-04-01

    Groundwater abstracted from aquifers underlying urban centres across India provide a vital source of domestic water. Abstraction from municipal and private supplies is considerable and growing rapidly with ever increasing demand for water from expanding urban populations. This trend is set to continue. The vulnerability of deeper aquifers (typically >100 m below ground) used for domestic water to contamination migration from often heavily contaminated shallow aquifer systems has not been studies in detail in India. This paper focusses on the occurrence of micro-organic contaminants within sedimentary aquifers beneath urban centres which are intensively pumped for drinking water and domestic use. New preliminary results from a detailed case study undertaken across Varanasi, a city with an estimated population of ca. 1.5 million in Uttar Pradesh. Micro -organic groundwater quality status and evolution with depth is investigated through selection of paired shallow and deep sites across the city. These results are considered within the context of paired groundwater residence time tracers within the top 150m within the sedimentary aquifer system. Groundwater emerging contaminant results are compared with surface water quality from the Ganges which is also used for drinking water supply. Broad screening for >800 micro-organic compounds was undertaken. Age dating tools were employed to constrain and inform a conceptual model of groundwater recharge and contaminant evolution within the sedimentary aquifer system.

  10. Investigation of an onsite wastewater treatment system in sandy soil: sorption and biodegradation of linear alkylbenzene sulfonate.

    Science.gov (United States)

    Doi, Jon; Marks, Kay H; DeCarvalho, Alvaro J; McAvoy, Drew C; Nielsen, Allen M; Kravetz, Louis; Cano, Manuel L

    2002-12-01

    The objective of this work was to determine the sorptive and biodegradable characteristics of linear alkylbenzene sulfonate (LAS) in a soil below a Florida, USA, septic system drainfield. Three distinct soil samples were collected from the septic system drainfield study site. These soils were used in laboratory sorption and biodegradation studies. Different concentrations of LAS were added, in radiolabeled and unlabeled forms, to a series of test vessels that contained upgradient groundwater and the soils collected from the study site. The sorption test was designed to determine the partitioning of LAS between groundwater and soil in each sample. Results indicated that the sorption distribution coefficient (Kd) decreased from 4.02 to 0.43 L/kg and that the rate of ultimate biodegradation (first-order rate constant, k1) decreased from 2.17 to 0.08/d with increasing distance (0.7-1.2 m vertically below ground surface [BGS] and 0 to 6.1 m horizontally) from the drainfield. The three soils showed 49.8 to 83.4% LAS mineralization (percentage of theoretical CO2) over 45- or 59-d test periods. These results demonstrate that subsurface soils in this system have the potential to sorb and biodegrade LAS.

  11. Potential water supply of a small reservoir and alluvial aquifer system in southern Zimbabwe

    NARCIS (Netherlands)

    Hamer, de W.; Love, D.; Owen, R.; Booij, M.J.; Hoekstra, A.Y.

    2007-01-01

    Groundwater use by accessing alluvial aquifers of non‐perennial rivers can be an important additional water resource in the semi‐arid region of southern Zimbabwe. The research objective of the study was to calculate the potential water supply for the upper‐Mnyabezi catchment under current conditions

  12. Potential water supply of a small reservoir and alluvial aquifer system in southern Zimbabwe

    NARCIS (Netherlands)

    Hamer, de W.; Love, D.; Owen, R.; Booij, M.J.; Hoekstra, A.Y.

    2008-01-01

    Groundwater use by accessing alluvial aquifers of non-perennial rivers can be an important additional water resource in the semi-arid region of southern Zimbabwe. The research objective of the study was to calculate the potential water supply for the upper-Mnyabezi catchment under current conditions

  13. Potential water supply of a small reservoir and alluvial aquifer system in southern Zimbabwe

    NARCIS (Netherlands)

    de Hamer, W.; Love, D.; Owen, R.; Booij, Martijn J.; Hoekstra, Arjen Ysbert

    2008-01-01

    Groundwater use by accessing alluvial aquifers of non-perennial rivers can be an important additional water resource in the semi-arid region of southern Zimbabwe. The research objective of the study was to calculate the potential water supply for the upper-Mnyabezi catchment under current conditions

  14. Potential water supply of a small reservoir and alluvial aquifer system in southern Zimbabwe

    NARCIS (Netherlands)

    de Hamer, W.; Love, D.; Owen, R.; Booij, Martijn J.; Hoekstra, Arjen Ysbert

    2007-01-01

    Groundwater use by accessing alluvial aquifers of non‐perennial rivers can be an important additional water resource in the semi‐arid region of southern Zimbabwe. The research objective of the study was to calculate the potential water supply for the upper‐Mnyabezi catchment under current conditions

  15. Direct heat resource assessment and subsurface information systems for geothermal aquifers; the Dutch perspetive

    NARCIS (Netherlands)

    Kramers, L.; Wees, van J.-D.; Pluymaekers, M.P.D.; Kronimus, A.; Boxem, T.

    2012-01-01

    A resource assessment methodology has been developed to designate prospective high permeable clastic aquifers and to assess the amount of potential geothermal energy in the Netherlands. It builds from the wealth of deep subsurface data from oil and gas exploration and production which is publicly an

  16. Hydrogeology of an alpine rockfall aquifer system and its role in flood attenuation and maintaining baseflow

    Directory of Open Access Journals (Sweden)

    U. Lauber

    2014-06-01

    Full Text Available The frequency and intensity of extreme hydrological events in alpine regions is projected to increase with climate change. The goal of this study was to better understand the functioning of aquifers composed of complex alluvial and rockfall deposits in alpine valleys and to quantify the role of these natural storage spaces in flood attenuation and baseflow maintenance. Geomorphological and hydrogeological mapping, tracer tests, and continuous flow measurements were conducted in the Reintal valley (German Alps, where runoff from a karst spring infiltrates into a series of postglacial alluvial/rockfall aquifers. During high-flow conditions, groundwater velocities of 30 m h−1 were determined along 500 m; hydrograph analyses revealed short lag times (5 h between discharge peaks upstream and downstream from the aquifer series; the maximum discharge ratio downstream (22 and the peak recession coefficient (0.196 d−1 are low compared with other alpine catchments. During low-flow conditions, the underground flow path length increased to 2 km and groundwater velocities decreased to 13 m h−1. Downstream hydrographs revealed a delayed discharge response after 101 h and peaks dampened by a factor of 1.5. These results indicate that alluvial/rockfall aquifers might play an important role in the flow regime and attenuation of floods in alpine regions.

  17. Direct heat resource assessment and subsurface information systems for geothermal aquifers; the Dutch perspetive

    NARCIS (Netherlands)

    Kramers, L.; Wees, van J.-D.; Pluymaekers, M.P.D.; Kronimus, A.; Boxem, T.

    2012-01-01

    A resource assessment methodology has been developed to designate prospective high permeable clastic aquifers and to assess the amount of potential geothermal energy in the Netherlands. It builds from the wealth of deep subsurface data from oil and gas exploration and production which is publicly an

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

    Science.gov (United States)

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

  19. Optimizing Managed Aquifer Recharge (MAR) Systems for Removal of Trace Organic Chemicals (TOrCs)

    KAUST Repository

    Alidina, Mazahirali

    2014-06-01

    Managed aquifer recharge (MAR) is a low-energy subsurface water treatment system with the potential of being an important component of sustainable water reuse schemes. Alongside common wastewater contaminants, MAR systems have been shown to attenuate a range of trace organic chemicals (TOrCs). Despite several factors being possibly important for TOrC attenuation, many have not been investigated in depth. This research effort investigated three factors affecting attenuation of the moderately degradable TOrCs: primary substrate, adaptation of the microbial community to presence of TOrCs, and groundwater temperature. The overall goal was to optimize TOrC attenuation using different MAR configurations considering how these factors affect TOrC attenuation. The primary substrate composition and concentration significantly impacted attenuation of the moderately degradable TOrCs. Lower primary substrate concentrations and more refractory carbon generally resulted in better TOrC transformation, a more diverse microbial community in the infiltration zone and more diverse capabilities for TOrC degradation. The enzyme group cytochrome P450 may be important for TOrC transformation since its genes were more abundant under carbon-starving primary substrate conditions. Adaptation of the microbial community by pre-exposure to TOrCs was not required in order to degrade them. However, adaptation to the primary substrate was necessary for TOrC biotransformation due to its effect on the microbial community. Attenuation of most TOrCs was unaffected by changes in temperature. Some moderately degradable TOrCs, however, were better attenuated at higher temperatures likely due to increased microbial activity. Others were better degraded at lower temperatures likely due to favorable sorption conditions. In the context of applying MAR systems to potential water reuse schemes within Saudi Arabia, a reconnaissance study of TOrC occurrence in treated wastewater effluents was undertaken. Most of

  20. Compressed air energy storage: Preliminary design and site development program in an aquifer. Volume 2: Utility system planning

    Science.gov (United States)

    1981-07-01

    The performance of an aquifer compressed air energy storage system was studied. The benefits derived from the integration of a compressed air energy storage facility with a hypothetical electrical network are analyzed. Scenarios of 100 percent coal, 50 percent coal and 50 percent nuclear, and 100 percent nuclear base load capacity additions were examined. Favorable economics are indicated when compressed air energy storage is installed as an alternative to combustion turbine peaking capacity on a system with a significant amount of oil fired generation.

  1. 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

    Previous studies of the hydrogeology of the surficial aquifer system in Palm Beach County, Florida, have focused mostly on the eastern one-half to one-third of the county in the more densely populated coastal areas. These studies have not placed the hydrogeology in a framework in which stratigraphic units in this complex aquifer system are defined and correlated between wells. Interest in the surficial aquifer system has increased because of population growth, westward expansion of urbanized areas, and increased utilization of surface-water resources in the central and western areas of the county. In 2004, the U.S. Geological Survey, in cooperation with the South Florida Water Management District, initiated an investigation to delineate the hydrogeologic framework of the surficial aquifer system in Palm Beach County, based on a lithostratigraphic framework, and to evaluate hydraulic properties and characteristics of units and permeable zones within this framework. A lithostratigraphic framework was delineated by correlating markers between all wells with data available based primarily on borehole natural gamma-ray geophysical log signatures and secondarily, lithologic characteristics. These correlation markers approximately correspond to important lithostratigraphic unit boundaries. Using the markers as guides to their boundaries, the surficial aquifer system was divided into three main permeable zones or subaquifers, which are designated, from shallowest to deepest, zones 1, 2, and 3. Zone 1 is above the Tamiami Formation in the Anastasia and Fort Thompson Formations. Zone 2 primarily is in the upper part or Pinecrest Sand Member of the Tamiami Formation, and zone 3 is in the Ochopee Limestone Member of the Tamiami Formation or its correlative equivalent. Differences in the lithologic character exist between these three zones, and these differences commonly include differences in the nature of the pore space. Zone 1 attains its greatest thickness (50 feet or more

  2. AMSR2 all-sky radiance assimilation and its impact on the analysis and forecast of Hurricane Sandy with a limited-area data assimilation system

    Directory of Open Access Journals (Sweden)

    Chun Yang

    2016-06-01

    Full Text Available A method to assimilate all-sky radiances from the Advanced Microwave Scanning Radiometer 2 (AMSR2 was developed within the Weather Research and Forecasting (WRF model's data assimilation (WRFDA system. The four essential elements are: (1 extending the community radiative transform model's (CRTM interface to include hydrometeor profiles; (2 using total water Qt as the moisture control variable; (3 using a warm-rain physics scheme for partitioning the Qt increment into individual increments of water vapour, cloud liquid water and rain; and (4 adopting a symmetric observation error model for all-sky radiance assimilation.Compared to a benchmark experiment with no AMSR2 data, the impact of assimilating clear-sky or all-sky AMSR2 radiances on the analysis and forecast of Hurricane Sandy (2012 was assessed through analysis/forecast cycling experiments using WRF and WRFDA's three-dimensional variational (3DVAR data assimilation scheme. With more cloud/precipitation-affected data being assimilated around tropical cyclone (TC core areas in the all-sky AMSR2 assimilation experiment, better analyses were obtained in terms of the TC's central sea level pressure (CSLP, warm-core structure and cloud distribution. Substantial (>20 % error reduction in track and CSLP forecasts was achieved from both clear-sky and all-sky AMSR2 assimilation experiments, and this improvement was consistent from the analysis time to 72-h forecasts. Moreover, the all-sky assimilation experiment consistently yielded better track and CSLP forecasts than the clear-sky did for all forecast lead times, due to a better analysis in the TC core areas. Positive forecast impact from assimilating AMSR2 radiances is also seen when verified against the European Center for Medium-Range Weather Forecasts (ECMWF analysis and the Stage IV precipitation analysis, with an overall larger positive impact from the all-sky assimilation experiment.

  3. Potential water supply of a small reservoir and alluvial aquifer system in southern Zimbabwe

    Science.gov (United States)

    de Hamer, W.; Love, D.; Owen, R.; Booij, M. J.; Hoekstra, A. Y.

    Groundwater use by accessing alluvial aquifers of non-perennial rivers can be an important additional water resource in the semi-arid region of southern Zimbabwe. The research objective of the study was to calculate the potential water supply for the upper-Mnyabezi catchment under current conditions and after implementation of two storage capacity measures. These measures are heightening the spillway of the ‘Mnyabezi 27’ dam and constructing a sand storage dam in the alluvial aquifer of the Mnyabezi River. The upper-Mnyabezi catchment covers approximately 22 km 2 and is a tributary of the Thuli River in southern Zimbabwe. Three coupled models are used to simulate the hydrological processes in the Mnyabezi catchment. The first is a rainfall-runoff model, based on the SCS-method. The second is a spreadsheet-based model of the water balance of the reservoir. The third is the finite difference groundwater model MODFLOW used to simulate the water balance of the alluvial aquifer. The potential water supply in the Mnyabezi catchment under current conditions ranges from 2107 m 3 (5.7 months) in a dry year to 3162 m 3 (8.7 months) in a wet year. The maximum period of water supply after implementation of the storage capacity measures in a dry year is 2776 m 3 (8.4 months) and in a wet year the amount is 3617 m 3 (10.8 months). The sand storage dam can only be used as an additional water resource, because the storage capacity of the alluvial aquifer is small. However, when an ephemeral river is underlain by a larger alluvial aquifer, a sand storage dam is a promising way of water supply for smallholder farmers in southern Zimbabwe.

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

    Science.gov (United States)

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

    2001-01-01

    Apparent ages of ground water are useful in the analysis of various components of flow systems, and results of this analysis can be incorporated into investigations of potential pathways of contaminant transport. This report presents the results of a study in 1997 by the U.S. Geological Survey (USGS), in cooperation with the Naval Weapons Station Yorktown, Base Civil Engineer, Environmental Directorate, to describe the apparent age of ground water of the shallow aquifer system at the Station. Chlorofluorocarbons (CFCs), tritium (3H), dissolved gases, stable isotopes, and water-quality field properties were measured in samples from 14 wells and 16 springs on the Station in March 1997.Nitrogen-argon recharge temperatures range from 5.9°C to 17.3°C with a median temperature of 10.9°C, which indicates that ground-water recharge predominantly occurs in the cold months of the year. Concentrations of excess air vary depending upon geohydrologic setting (recharge and discharge areas). Apparent ground-water ages using a CFC-based dating technique range from 1 to 48 years with a median age of 10 years. The oldest apparent CFC ages occur in the upper parts of the Yorktown-Eastover aquifer, whereas the youngest apparent ages occur in the Columbia aquifer and the upper parts of the discharge area setting, especially springs. The vertical distribution of apparent CFC ages indicates that groundwater movement between aquifers is somewhat retarded by the leaky confining units, but the elapsed time is relatively short (generally less than 35 years), as evidenced by the presence of CFCs at depth. The identification of binary mixtures by CFC-based dating indicates that convergence of flow lines occurs not only at the actual point of discharge, but also in the subsurface.The CFC-based recharge dates are consistent with expected 3H concentrations measured in the water samples from the Station. The concentration of 3H in ground water ranges from below the USGS laboratory minimum

  5. Analysis of groundwater dynamics in the complex aquifer system of Kazan Trona, Turkey, using environmental tracers and noble gases

    Science.gov (United States)

    Arslan, Sebnem; Yazicigil, Hasan; Stute, Martin; Schlosser, Peter; Smethie, William M.

    2015-02-01

    The Eocene deposits of Kazan Basin in Turkey contain a rare trona mineral which is planned to be extracted by solution mining. The complex flow dynamics and mixing mechanisms as noted from previous hydraulic and hydrochemical data need to be augmented with environmental tracer and noble gas data to develop a conceptual model of the system for the assessment of the impacts of the mining and to develop sustainable groundwater management policies throughout the area. The tracers used include the stable isotopes of water (δ2H, δ18O), δ13C and 14C of dissolved inorganic carbon (DIC), tritium (3H), the chlorofluorocarbons CFC-11 and CFC-12, and the noble gases He and Ne. The system studied consists of three aquifers: shallow, middle, and deep. CFC data indicate modern recharge in the shallow system. The estimates of ages through 14C dating for the deeper aquifer system are up to 34,000 years. Helium concentrations cover a wide range of values from 5 × 10-8 to 1.5 × 10-5 cm3 STP/g. 3He/4He ratios vary from 0.09RA to 1.29RA (where RA is the atmospheric 3He/4He ratio of 1.384 × 10-6), the highest found in water from the shallow aquifer. Mantle-derived 3He is present in some of the samples indicating upward groundwater movement, possibly along a NE-SW-striking fault-like feature in the basin.

  6. Interaction of various flow systems in small alpine catchments: conceptual model of the upper Gurk Valley aquifer, Carinthia, Austria

    Science.gov (United States)

    Hilberg, Sylke; Riepler, Franz

    2016-08-01

    Small alpine valleys usually show a heterogeneous hydraulic situation. Recurring landslides create temporal barriers for the surface runoff. As a result of these postglacial processes, temporal lakes form, and thus lacustrine fine-grained sedimentation intercalates with alluvial coarse-grained layers. A sequence of alluvial sediments (confined and thus well protected aquifers) and lacustrine sediments (aquitards) is characteristic for such an environment. The hydrogeological situation of fractured hard-rock aquifers in the framing mountain ranges is characterized by superficially high hydraulic conductivities as the result of tectonic processes, deglaciation and postglacial weathering. Fracture permeability and high hydraulic gradients in small-scaled alpine catchments result in the interaction of various flow systems in various kinds of aquifers. Spatial restrictions and conflicts between the current land use and the requirements of drinking-water protection represent a special challenge for water resource management in usually densely populated small alpine valleys. The presented case study describes hydrogeological investigations within the small alpine valley of the upper Gurktal (Upper Carinthia, Austria) and the adjacent Höllenberg Massif (1,772 m above sea level). Hydrogeological mapping, drilling, and hydrochemical and stable isotope analyses of springs and groundwater were conducted to identify a sustainable drinking-water supply for approximately 1,500 inhabitants. The results contribute to a conceptual hydrogeological model with three interacting flow systems. The local and the intermediate flow systems are assigned to the catchment of the Höllenberg Massif, whereas the regional flow system refers to the bordering Gurktal Alps to the north and provides an appropriate drinking water reservoir.

  7. Sandy PMO Disaster Relief Appropriations Act of 2013 Financial Data

    Data.gov (United States)

    Department of Homeland Security — Sandy PMO: Disaster Relief Appropriations Act of 2013 (Sandy Supplemental Bill) Financial Data. This is the Sandy Supplemental Quarterly Financial Datasets that are...

  8. Characterization of Predominant Reductants in an Anaerobic Leachate-Contaminated Aquifer by Nitroaromatic Probe Compounds

    DEFF Research Database (Denmark)

    Rügge, Kirsten; Hofstetter, Thomas B.; Haderlein, Stefan B.;

    1998-01-01

    The biogeochemical processes controlling the reductive transformation of contaminants in an anaerobic aquifer were inferred from the relative reactivity patterns of redox-sensitive probe compounds. The fate of five nitroaromatic compounds (NACs) was monitored under different redox conditions in a...... results suggest that Fe(ll) associated with ferric iron minerals is a highly reactive reductant in anaerobic aquifers, which may also determine the fate of other classes of reducible contaminants such as halogenated solvents, azo compounds, sulfoxides, chromate, or arsenate....... in a landfill leachate plume of a sandy aquifer. Results of field experiments (continuous injection and in situ microcosms) were compared to the findings of laboratory batch and column experiments (using aquifer matrix and model systems for sulfate-and iron-reducing conditions). NACs were transformed within 2...... potential reductants (e.g., H(2)S/HS(-), Fe(II)(aq), reduced organic matter, microorganisms), the patterns of relative reactivity of the probe compounds indicated that ferrous iron associated with iron(lll) (hydr)oxide surfaces was the dominant reductant throughout the anaerobic region of the plume. Our...

  9. Iron in the Middle Devonian aquifer system and its removal at Võru County water treatment plants, Estonia

    Directory of Open Access Journals (Sweden)

    Mariina Hiiob

    2012-08-01

    Full Text Available Groundwater abstracted from the Middle Devonian aquifer system is the main source of drinking water in South Estonia. High iron and manganese concentrations in groundwater are the greatest problems in this region. The total iron concentrations up to 16 mg L–1 are mainly caused by a high Fe2+ content in water, pointing to the dominance of reducing conditions in the aquifer system. A pilot study was carried out to estimate the effectiveness of 20 groundwater purification plants with eight different water treatment systems (aeration combined with Manganese Greensand, Birm, Nevtraco, Hydrolit-Mn, Magno-Dol and quartz sand filters in Võru County. The results demonstrate that in most cases the systems with pre-aeration effectively purify groundwater from iron, but only 13 out of 20 water treatment plants achieved a reduction of iron concentration to the level fixed in drinking water requirements (0.2 mg L–1. Manganese content decreased below the maximum allowed concentration in only 25% of systems and in cases where the filter media was Birm or quartz sand and pre-oxidation was applied. The study showed that the high level of iron purification does not guarantee effective removal of manganese.

  10. Cost-Benefit Analysis of the Managed Aquifer Recharge System for Irrigation under Climate Change Conditions in Southern Spain

    National Research Council Canada - National Science Library

    Carmen Ruperez-Moreno; Julio Perez-Sanchez; Javier Senent-Aparicio; Pilar Flores-Asenjo; Carmen Paz-Aparicio

    2017-01-01

    .... In the integrated water resource management (IWRM), managed aquifer recharge (MAR) offers efficient solutions to protect, conserve, and ensure survival of aquifers and associated ecosystems, as the Water Framework Directive requires...

  11. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent of the low-permeable areas of the Floridan aquifer system in the Gulf Trough

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  12. Impact of leaky wells on nitrate cross-contamination in a layered aquifer system: Methodology for and demonstration of quantitative assessment and prediction

    Science.gov (United States)

    Koh, Eun-Hee; Lee, Eunhee; Lee, Kang-Kun

    2016-10-01

    Poorly constructed wells can cause deterioration of groundwater quality by carrying surface contaminants into a deep subsurface aquifer system. In this study, the impact of leaky wells on groundwater contamination was quantitatively evaluated in a layered aquifer system of the Gosan agricultural fields, Jeju Island, Korea, where degradation in groundwater quality by nitrate has been reported. We introduce a leaky-well module and a double-domain integration method to compute nitrate cross-contamination through a layered aquifer system. The simulation results clearly revealed that the leaky wells rapidly degraded the water quality of the underlying aquifer by acting as a direct pathway for nitrate-rich shallow groundwater. The model results predicted that in order to decrease the NO3-N concentration at the regional groundwater wells below the maximum contamination level (MCL), the maximum allowable fertilizer amount of Gosan would be 45-65% of the currently applied fertilizer level, whereas sealing of the regional groundwater wells would rapidly decrease the NO3-N concentration below the MCL without reducing fertilizer usage. Our study demonstrated that the well conditions and hydrogeological system play major roles in the occurrence of nitrate in the underlying aquifer in Gosan; therefore, a proper groundwater management plan against nitrate contamination should be established on the basis of a comprehensive understanding of the hydrogeologic system of the area.

  13. Spatial distribution of sandy desertificationchange in the west of Jilin Province

    Institute of Scientific and Technical Information of China (English)

    LIUHuiqing; XUJiawei; LVXinmiao

    2003-01-01

    The sandy land of the western part of Jilin Province is located in the ecotone of semi-humid and semi-arid area in the temperate zone of China. The sandy desertification has widely spread in the region because of the vulnerable natural conditions and the unreasonable human activity; as a result of this, the precious land resources and the economic development in the area have been seriously impacted. In this paper, the sandy land ecologic environment geographic information system is established based on the multi-spectral, multi-temporal Landsat TM images and field investigation. The comprehensive indexes of sandy desertification extent assessment which include vegetation degradation, wind erosion extent and soil depth are presented to classify the sandy land in western Jilin into three levels--slight, moderate and severe sandy desertification with the support of GIS platform. The results demonstrate that the sandy desertification has been partly controlled in the past twenty years, except some small sites. However, this doesn't necessarily mean that there is nothing for more concern. The two main causes of sandy desertification have not been eliminated yet, one is its natural factor, especially the physical and chemical characters of sandy soil and dry climate; another is the immoderate economic activity of human being that has highly accelerated the sandy desertification process.

  14. Land Subsidence and Aquifer-System Compaction in the Tucson Active Management Area, South-Central Arizona, 1987-2005

    Science.gov (United States)

    Carruth, Rob; Flynn, Pool; Donald, R.; Anderson, Carl E.

    2007-01-01

    The U.S. Geological Survey monitors land subsidence and aquifer-system compaction caused by ground-water depletion in Tucson Basin and Avra Valley - two of the three alluvial basins within the Tucson Active Management Area. In spring 1987, the Global Positioning System was used to measure horizontal and vertical positions for bench marks at 43 sites to establish a network for monitoring land subsidence in Tucson Basin and Avra Valley. Between 1987 and 2005, the original number of subsidence monitoring stations was gradually increased to more than 100 stations to meet the need for information in the growing metropolitan area. Data from approximately 60 stations common to the Global Positioning System surveys done after an initial survey in 1987 are used to document land subsidence. For the periods of comparison, average land-surface deformation generally is less than the maximum subsidence at an individual station and takes into account land-surface recovery from elastic aquifer-system compaction. Between 1987 and 1998, as much as 3.2 inches of subsidence occurred in Tucson Basin and as much as 4 inches of subsidence occurred in Avra Valley. For the 31 stations that are common to both the 1987 and 1998 Global Positioning System surveys, the average subsidence during the 11-year period was about 0.5 inch in Tucson Basin and about 1.2 inches in Avra Valley. For the approximately 60 stations that are common to both the 1998 and 2002 Global Positioning System surveys, the data indicate that as much as 3.5 inches of subsidence occurred in Tucson Basin and as much as 1.1 inches of subsidence occurred in Avra Valley. The average subsidence for the 4-year period is about 0.4 inch in Tucson Basin and 0.6 inch in Avra Valley. Between the 2002 and the 2005 Global Positioning System surveys, the data indicate that as much as 0.2 inch of subsidence occurred in Tucson Basin and as much as 2.2 inches of subsidence occurred in Avra Valley. The average subsidence for the 3-year

  15. Groundwater flow dynamics in the complex aquifer system of Gidabo River Basin (Ethiopian Rift): a multi-proxy approach

    Science.gov (United States)

    Mechal, Abraham; Birk, Steffen; Dietzel, Martin; Leis, Albrecht; Winkler, Gerfried; Mogessie, Aberra; Kebede, Seifu

    2017-03-01

    Hydrochemical and isotope data in conjunction with hydraulic head and spring discharge observations were used to characterize the regional groundwater flow dynamics and the role of the tectonic setting in the Gidabo River Basin, Ethiopian Rift. Both groundwater levels and hydrochemical and isotopic data indicate groundwater flow from the major recharge area in the highland and escarpment into deep rift floor aquifers, suggesting a deep regional flow system can be distinguished from the shallow local aquifers. The δ18O and δ2H values of deep thermal (≥30 °C) groundwater are depleted relative to the shallow (floor. Based on the δ18O values, the thermal groundwater is found to be recharged in the highland around 2,600 m a.s.l. and on average mixed with a proportion of 30 % shallow groundwater. While most groundwater samples display diluted solutions, δ13C data of dissolved inorganic carbon reveal that locally the thermal groundwater near fault zones is loaded with mantle CO2, which enhances silicate weathering and leads to anomalously high total dissolved solids (2,000-2,320 mg/l) and fluoride concentrations (6-15 mg/l) exceeding the recommended guideline value. The faults are generally found to act as complex conduit leaky barrier systems favoring vertical mixing processes. Normal faults dipping to the west appear to facilitate movement of groundwater into deeper aquifers and towards the rift floor, whereas those dipping to the east tend to act as leaky barriers perpendicular to the fault but enable preferential flow parallel to the fault plane.

  16. Assessing the vulnerability of public-supply wells to contamination--Glacial aquifer system in Woodbury, Connecticut

    Science.gov (United States)

    Jagucki, Martha L.; Brown, Craig J.; Starn, J. Jeffrey; Eberts, Sandra M.

    2010-01-01

    This fact sheet highlights findings from the vulnerability study of a public-supply well in Woodbury, Connecticut. The well typically produces water at the rate of 72 gallons per minute from the glacial aquifer system in the Pomperaug River Basin. Water samples were collected at the public-supply well and at monitoring wells installed in or near the simulated zone of contribution to the supply well. Samples of untreated water from the public-supply wellhead contained several types of undesirable constituents, including 11 volatile organic compounds (VOCs), nitrate, pesticides, uranium, and radon. Most of these constituents were detected at concentrations below drinking-water standards, where such standards exist. Only concentrations of the VOC trichlorethylene exceeded the Maximum Contaminant Level (MCL) of 5 micrograms per liter (ug/L) established by U.S. Environmental Protection Agency for drinking water. Radon concentrations exceeded a proposed-but not finalized-MCL of 300 picocuries per liter (pCi/L). Overall, the study findings point to four main factors that affect the movement and fate of contaminants and the vulnerability of the public-supply well in Woodbury: (1) groundwater age (how long ago water entered, or recharged, the aquifer); (2) the percentage of recharge received through urban areas; (3) the percentage of recharge received through dry wells and their proximity to the public-supply well; and (4) natural geochemical processes occurring within the aquifer system; that is, processes that affect the amounts and distribution of chemical substances in aquifer sediments and groundwater. A computer-model simulation of groundwater flow to the public-supply well was used to estimate the age of water particles entering the well along the length of the well screen. About 90 percent of the simulated flow to the well consists of water that entered the aquifer 9 or fewer years ago. Such young water is vulnerable to contaminants resulting from human activities

  17. Hydrogeologic framework and hydrologic budget components of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Kahle, S.C.; Morgan, D.S.; Welch, W.B.; Ely, D.M.; Hinkle, S.R.; Vaccaro, J.J.; Orzol, L.L.

    2011-01-01

    The Columbia Plateau Regional Aquifer System (CPRAS) covers an area of about 44,000 square miles in a structural and topographic basin within the drainage of the Columbia River in Washington, Oregon, and Idaho. The primary aquifers are basalts of the Columbia River Basalt Group (CRBG) and overlying sediment. Eighty percent of the groundwater use in the study area is for irrigation, in support of a $6 billion per year agricultural economy. Water-resources issues in the Columbia Plateau include competing agricultural, domestic, and environmental demands. Groundwater levels were measured in 470 wells in 1984 and 2009; water levels declined in 83 percent of the wells, and declines greater than 25 feet were measured in 29 percent of the wells. Conceptually, the system is a series of productive basalt aquifers consisting of permeable interflow zones separated by less permeable flow interiors; in places, sedimentary aquifers overly the basalts. The aquifer system of the CPRAS includes seven hydrogeologic units-the overburden aquifer, three aquifer units in the permeable basalt rock, two confining units, and a basement confining unit. The overburden aquifer includes alluvial and colluvial valley-fill deposits; the three basalt units are the Saddle Mountains, Wanapum, and Grande Ronde Basalts and their intercalated sediments. The confining units are equivalent to the Saddle Mountains-Wanapum and Wanapum-Grande Ronde interbeds, referred to in this study as the Mabton and Vantage Interbeds, respectively. The basement confining unit, referred to as Older Bedrock, consists of pre-CRBG rocks that generally have much lower permeabilities than the basalts and are considered the base of the regional flow system. Based on specific-capacity data, median horizontal hydraulic conductivity (Kh) values for the overburden, basalt units, and bedrock are 161, 70, and 6 feet per day, respectively. Analysis of oxygen isotopes in water and carbon isotopes in dissolved inorganic carbon from

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

    Directory of Open Access Journals (Sweden)

    Ajda Koceli

    2013-12-01

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

  19. Inquiry and Aquifers.

    Science.gov (United States)

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

    2001-01-01

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

  20. Inquiry and Aquifers.

    Science.gov (United States)

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

    2001-01-01

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

  1. Hurricane Sandy Poster (October 29, 2012)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Sandy poster. Multi-spectral image from Suomi-NPP shows Hurricane Sandy approaching the New Jersey Coast on October 29, 2012. Poster size is approximately...

  2. Approaches to optimal aquifer management and intelligent control in a multiresolutional decision support system

    Science.gov (United States)

    Orr, Shlomo; Meystel, Alexander M.

    2005-03-01

    Despite remarkable new developments in stochastic hydrology and adaptations of advanced methods from operations research, stochastic control, and artificial intelligence, solutions of complex real-world problems in hydrogeology have been quite limited. The main reason is the ultimate reliance on first-principle models that lead to complex, distributed-parameter partial differential equations (PDE) on a given scale. While the addition of uncertainty, and hence, stochasticity or randomness has increased insight and highlighted important relationships between uncertainty, reliability, risk, and their effect on the cost function, it has also (a) introduced additional complexity that results in prohibitive computer power even for just a single uncertain/random parameter; and (b) led to the recognition in our inability to assess the full uncertainty even when including all uncertain parameters. A paradigm shift is introduced: an adaptation of new methods of intelligent control that will relax the dependency on rigid, computer-intensive, stochastic PDE, and will shift the emphasis to a goal-oriented, flexible, adaptive, multiresolutional decision support system (MRDS) with strong unsupervised learning (oriented towards anticipation rather than prediction) and highly efficient optimization capability, which could provide the needed solutions of real-world aquifer management problems. The article highlights the links between past developments and future optimization/planning/control of hydrogeologic systems. Malgré de remarquables nouveaux développements en hydrologie stochastique ainsi que de remarquables adaptations de méthodes avancées pour les opérations de recherche, le contrôle stochastique, et l'intelligence artificielle, solutions pour les problèmes complexes en hydrogéologie sont restées assez limitées. La principale raison est l'ultime confiance en les modèles qui conduisent à des équations partielles complexes aux paramètres distribués (PDE) à une

  3. A conceptual hydrogeologic model for the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers in the Pecos County region, Texas

    Science.gov (United States)

    Thomas, Jonathan V.; Stanton, Gregory P.; Bumgarner, Johnathan R.; Pearson, Daniel K.; Teeple, Andrew; Houston, Natalie A.; Payne, Jason; Musgrove, MaryLynn

    2013-01-01

    The Edwards-Trinity aquifer is a vital groundwater resource for agricultural, industrial, and municipal uses in the Trans-Pecos region of west Texas. A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system in the 4,700 square-mile study area was developed by the U.S. Geological Survey (USGS) in cooperation with the Middle Pecos Groundwater Conservation District, Pecos County, City of Fort Stockton, Brewster County, and Pecos County Water Control and Improvement District No. 1. The model was developed to gain a better understanding of the groundwater system and to establish a scientific foundation for resource-management decisions. Data and information were collected or obtained from various sources to develop the model. Lithologic information obtained from well reports and geophysical data were used to describe the hydrostratigraphy and structural features of the groundwater system, and aquifer-test data were used to estimate aquifer hydraulic properties. Groundwater-quality data were used to evaluate groundwater-flow paths, water and rock interaction, aquifer interaction, and the mixing of water from different sources. Groundwater-level data also were used to evaluate aquifer interaction as well as to develop a potentiometric-surface map, delineate regional groundwater divides, and describe regional groundwater-flow paths.

  4. A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers in the Pecos County region, Texas

    Science.gov (United States)

    Bumgarner, Johnathan R.; Stanton, Gregory P.; Teeple, Andrew; Thomas, Jonathan V.; Houston, Natalie A.; Payne, Jason; Musgrove, MaryLynn

    2012-01-01

    A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers, which include the Pecos Valley, Igneous, Dockum, Rustler, and Capitan Reef aquifers, was developed as the second phase of a groundwater availability study in the Pecos County region in west Texas. The first phase of the study was to collect and compile groundwater, surface-water, water-quality, geophysical, and geologic data in the area. The third phase of the study involves a numerical groundwater-flow model of the Edwards-Trinity aquifer in order to simulate groundwater conditions based on various groundwater-withdrawal scenarios. Resource managers plan to use the results of the study to establish management strategies for the groundwater system. The hydrogeologic framework is composed of the hydrostratigraphy, structural features, and hydraulic properties of the groundwater system. Well and geophysical logs were interpreted to define the top and base surfaces of the Edwards-Trinity aquifer units. Elevations of the top and base of the Edwards-Trinity aquifer generally decrease from the southwestern part of the study area to the northeast. The thicknesses of the Edwards-Trinity aquifer units were calculated using the interpolated top and base surfaces of the hydrostratigraphic units. Some of the thinnest sections of the aquifer were in the eastern part of the study area and some of the thickest sections were in the Pecos, Monument Draw, and Belding-Coyanosa trough areas. Normal-fault zones, which formed as growth and collapse features as sediments were deposited along the margins of more resistant rocks and as overlying sediments collapsed into the voids created by the dissolution of Permian-age evaporite deposits, were delineated based on the interpretation of hydrostratigraphic cross sections. The lowest aquifer transmissivity values were measured in the eastern part of the study area; the highest transmissivity values were

  5. On Sandy Shores. Teacher's Guide.

    Science.gov (United States)

    Strang, Craig; And Others

    The activities in this guide (for grades 2-4) transport students to the sandy shore, one of the most fascinating ecosystems on the planet. At this ecological juncture a multiplicity of life forms find ways to survive, thrive, and interact with each other. Using a wide variety of learning formats, students explore and deepen their understanding of…

  6. Water level response in back-barrier bays unchanged following Hurricane Sandy

    Science.gov (United States)

    Aretxabaleta, Alfredo L.; Butman, Bradford; Ganju, Neil K.

    2014-01-01

    On 28–30 October 2012, Hurricane Sandy caused severe flooding along portions of the northeast coast of the United States and cut new inlets across barrier islands in New Jersey and New York. About 30% of the 20 highest daily maximum water levels observed between 2007 and 2013 in Barnegat and Great South Bay occurred in 5 months following Hurricane Sandy. Hurricane Sandy provided a rare opportunity to determine whether extreme events alter systems protected by barrier islands, leaving the mainland more vulnerable to flooding. Comparisons between water levels before and after Hurricane Sandy at bay stations and an offshore station show no significant differences in the transfer of sea level fluctuations from offshore to either bay following Sandy. The post-Hurricane Sandy bay high water levels reflected offshore sea levels caused by winter storms, not by barrier island breaching or geomorphic changes within the bays.

  7. Hydrogeological investigation of an oasis-system aquifer in arid southeastern Morocco by development of a groundwater flow model

    Science.gov (United States)

    Bouaamlat, Ilias; Larabi, Abdelkader; Faouzi, Mohamed

    2016-09-01

    Groundwater of the Tafilalet oasis system (TOS) is an important water resource in the lower Ziz and Rheris valleys of arid southeastern Morocco. The unconfined aquifer is exploited for domestic consumption and irrigation. A groundwater flow model was developed to assess the impact of climatic variations and development, including the construction of hydraulic structures, on the hydrodynamic behavior of the aquifer. Numerical simulations were performed by implementing a spatial database within a geographic information system and using the Arc Hydro Groundwater tool with the code MODFLOW-2000. The results of steady-state and transient simulations between 1960 and 2011 show that the water table is at equilibrium between recharge, which is mainly by surface-water infiltration, and discharge by evapotranspiration. After the commissioning of the Hassan Addakhil dam in 1971, hydraulic heads became more sensitive to annual variations than to seasonal variations. Heads are also influenced by recurrent droughts and the highest water-level changes are recorded in irrigated areas. The model provides a way of managing groundwater resources in the TOS. It can be used as a tool to predict the impact of different management plans for the protection of groundwater against overexploitation and deterioration of water quality.

  8. Dealing with load imbalances and aquifer heterogeneity : design and monitoring of the ATES system in Agassiz, BC

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D.M.; Bridger, D.W. [Simon Fraser Univ., Burnaby, BC (Canada)

    2003-07-01

    The development and implementation of aquifer thermal energy storage (ATES) is often hindered by climate conditions that create load imbalances, and by complex hydrogeology that creates uncertainties in design. Due consideration was given to load imbalance and aquifer complexity in the case of the ATES system at Agriculture and Agri-Foods Canada's new laboratory facility located in Agassiz, British Columbia. Heat and cold energy to the building are supplied by four production wells, with an operational design which favours seasonal energy storage. A fifth well was drilled so that it could act as a heat dissipation well. Blank and screen sections were placed in a manner to reduce or eliminate hydraulic and thermal short-circuiting within gravel layers between wells. Within the well field are monitoring wells, which are used for temperature logging. The temperature logs showed that some thermal breakthrough took place during the first year of operation, and that the system operated under an excessive cooling load throughout the period. 8 refs., 1 tab., 5 figs.

  9. Ground-Water Budgets for the Wood River Valley Aquifer System, South-Central Idaho, 1995-2004

    Science.gov (United States)

    Bartolino, James R.

    2009-01-01

    The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Haley, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system which consists of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on ground water for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the ground-water resource. To help address these concerns this report describes a ground-water budget developed for the Wood River Valley aquifer system for three selected time periods: average conditions for the 10-year period 1995-2004, and the single years of 1995 and 2001. The 10-year period 1995-2004 represents a range of conditions in the recent past for which measured data exist. Water years 1995 and 2001 represent the wettest and driest years, respectively, within the 10-year period based on precipitation at the Ketchum Ranger Station. Recharge or inflow to the Wood River Valley aquifer system occurs through seven main sources (from largest to smallest): infiltration from tributary canyons, streamflow loss from the Big Wood River, areal recharge from precipitation and applied irrigation water, seepage from canals and recharge pits, leakage from municipal pipes, percolation from septic systems, and subsurface inflow beneath the Big Wood River in the northern end of the valley. Total estimated mean annual inflow or recharge to the aquifer system for 1995-2004 is 270,000 acre-ft/yr (370 ft3/s). Total recharge for the wet year 1995 and the dry year 2001 is estimated to be 270,000 acre-ft/yr (370 ft3/s) and 220,000 acre-ft/yr (300 ft3/s), respectively. Discharge or outflow from the Wood River Valley aquifer system occurs through

  10. Discrete Analytic Domains: a New Technique for Groundwater Flow Modeling in Layered, Anisotropic, and Heterogeneous Aquifer Systems

    Science.gov (United States)

    Fitts, C. R.

    2004-12-01

    A new technique for modeling groundwater flow with analytic solutions is presented. It allows modeling of layered aquifer systems with complex heterogeneity and anisotropy. As with previous AEM techniques, flow in each layer is modeled with two-dimensional analytic solutions, there is high accuracy and resolution, the domain is not discretized into grid blocks or elements, and the modeled area can easily be altered and expanded in the midst of the modeling process. This method differs from previous Analytic Element Method (AEM) techniques by allowing general anisotropy conditions in the aquifer. The flow field is broken into discrete polygonal domains, each with its own definition of isotropic or anisotropic aquifer parameters. An advantage of this approach is that the anisotropy orientation and ratio can differ from one domain to another, a capability not possible with the "infinite domain" of previous AEM formulations. With this approach, the potential and discharge vector functions at a point are the sum of contributions from elements within or on the boundary of the domain containing the point. Unlike previous AEM schemes, elements beyond the domain boundary don't contribute to these functions. Once a solution is in hand, less computation is required to evaluate heads and discharges because fewer elements contribute to the equations. This computational efficiency could prove a significant advantage in large regional models and in solute transport models that use a flow model's velocity field. This technique allows multiple aquifer layers to be stacked vertically, and it has the novel ability to have more layers in the area of interest than in distant areas. This feature can save significant computation and input effort by concentrating layering detail only where it is needed and warranted by data. The boundary conditions at line element boundaries are approximated, including the continuity of flow and head across heterogeneity boundaries. By using high

  11. Measuring Sandy Bottom Dynamics by Exploiting Depth from Stereo Video Sequences

    DEFF Research Database (Denmark)

    Musumeci, Rosaria E.; Farinella, Giovanni M.; Foti, Enrico;

    2013-01-01

    In this paper an imaging system for measuring sandy bottom dynamics is proposed. The system exploits stereo sequences and projected laser beams to build the 3D shape of the sandy bottom during time. The reconstruction is used by experts of the field to perform accurate measurements and analysis i...

  12. Time-series ground-water-level and aquifer-system compaction data, Edwards Air Force Base, Antelope Valley, California, January 1991 through September 1993

    Science.gov (United States)

    Freeman, L.A.

    1996-01-01

    As part of a study by the U.S. Geological Survey, a monitoring program was implemented to collect time-series ground-water-level and aquifer-system compaction data at Edwards Air Force Base, California. The data presented in this report were collected from 18 piezometers, 3 extensometers, 1 barometer, and 1 rain gage from January 1991 through September 1993. The piezometers and extensometers are at eight sites in the study area. This report discusses the ground-water-level and aquifer-system compaction monitoring networks, and presents the recorded data in graphs. The data reported are available in the data base of the U.S. Geological Survey.

  13. Assessing the vulnerability of public-supply wells to contamination: Rio Grande aquifer system in Albuquerque, New Mexico

    Science.gov (United States)

    Jagucki, Martha L.; Bexfield, Laura M.; Heywood, Charles E.; Eberts, Sandra M.

    2012-01-01

    This fact sheet highlights findings from the vulnerability study of a public-supply well in Albuquerque, New Mexico (hereafter referred to as “the study well”). The study well produces about 3,000 gallons of water per minute from the Rio Grande aquifer system. Water samples were collected at the study well, at two other nearby public-supply wells, and at monitoring wells installed in or near the simulated zone of contribution to the study well. Untreated water samples from the study well contained arsenic at concentrations exceeding the Maximum Contaminant Level (MCL) of 10 micrograms per liter (µg/L) established by the U.S. Environmental Protection Agency for drinking water. Volatile organic compounds (VOCs) and nitrate also were detected, although at concentrations at least an order of magnitude less than established drinking-water standards, where such standards exist. Overall, study findings point to four primary influences on the movement and (or) fate of contaminants and the vulnerability of the public-supply well in Albuquerque: (1) groundwater age (how long ago water entered, or recharged, the aquifer), (2) groundwater development (introduction of manmade recharge and discharge sources), (3) natural geochemical conditions of the aquifer, and (4) seasonal pumping stresses. Concentrations of the isotope carbon-14 indicate that groundwater from most sampled wells in the local study area is predominantly water that entered, or recharged, the aquifer more than 6,000 years ago. However, the additional presence of the age tracer tritium in several groundwater samples at concentrations above 0.3 tritium units indicates that young (post-1950) recharge is reaching the aquifer across broad areas beneath Albuquerque. This young recharge is mixing with the thousands-of-years-old water, is migrating to depths as great as 245 feet below the water table, and is traveling to some (but not all) of the public-supply wells sampled. Most groundwater samples containing a

  14. GROUNDWATER QUALITY EVALUATION OF PERMANENT PRESERVATION AREAS (GUARANI AQUIFER SYSTEM - GAS, RIO PARDO HYDROGRAPHICAL BASIN, RS, BRAZIL

    Directory of Open Access Journals (Sweden)

    Adilson Ben da Costa

    2010-06-01

    Full Text Available The aim of this research was to evaluate the quality of groundwater in areas of permanent preservation (Guarani Aquifer System – GAS in the Rio Pardo Hydrographical Basin, RS, Brazil, using physical, chemical and microbiological variables, based on resolution no. 396/2008 of the National Council on the Environment - CONAMA. Nine sampling points were distributed throughout the basin, where groundwater was classified as the major ions through the Piper diagram. The results indicated that most of the wells evaluated were classified in Class 4, accounting for water uses less restrictive. However, it should be considered that the aquifers are characterize by different geological conditions, having intrinsical physical, chemical and biological variables with hydrogeochemical variations, requiring that their quality levels are often based on these characteristics, as noted in diagram Piper, where the samples P1, P2, P3, P5 and P9 were classified as calcium bicarbonate, the waters of the points P4, P6, P7 as sodium bicarbonate and P8 as sulfated. It was found that the quality of water from wells with depths less than 6 m are becoming more vulnerable due to anthropogenic activities, as showing by the concentration of nitrate, total and thermotolerant coliforms, while the quality of water from deeper wells basically depends on their hydrogeological and hydrogeochemical characteristics based on the concentration of sodium and sulfate variables. However, they also showed contamination by human activities, mainly by the nitrate variable.

  15. A conceptual framework and monitoring strategy for movement of saltwater in the coastal plain aquifer system of Virginia

    Science.gov (United States)

    Mcfarland, E. Randolph

    2015-09-04

    A conceptual framework synthesizes previous studies to provide an understanding of conditions, processes, and relations of saltwater to groundwater withdrawal in the Virginia Coastal Plain aquifer system. A strategy for monitoring saltwater movement is based on spatial relations between the saltwater-transition zone and 612 groundwater-production wells that were regulated during 2013 by the Virginia Department of Environmental Quality. The vertical position and lateral distance and direction of the bottom of each production well’s screened interval was calculated relative to previously published groundwater chloride iso-concentration surfaces. Spatial analysis identified 81 production wells completed in the Yorktown-Eastover and Potomac aquifers that are positioned in closest proximity to the 250-milligrams-per-liter chloride surface, and from which chloride concentrations are most likely to increase above the U.S. Environmental Protection Agency’s 250-milligrams-per-liter secondary maximum-contaminant level. Observation wells are specified to distinguish vertical upconing from lateral intrusion among individual production wells. To monitor upconing, an observation well is to be collocated with each production well and completed at about the altitude of the 250-milligrams-per-liter chloride iso-concentration surface. To monitor lateral intrusion, a potential location of an observation well is projected from the bottom of each production well’s screened interval, in the lateral direction to the underlying chloride surface to a distance of 1 mile.

  16. Three-Dimensional Geologic Framework Model for a Karst Aquifer System, Hasty and Western Grove Quadrangles, Northern Arkansas

    Science.gov (United States)

    Turner, Kenzie J.; Hudson, Mark R.; Murray, Kyle E.; Mott, David N.

    2007-01-01

    Understanding ground-water flow in a karst aquifer benefits from a detailed conception of the three-dimensional (3D) geologic framework. Traditional two-dimensional products, such as geologic maps, cross-sections, and structure contour maps, convey a mental picture of the area but a stronger conceptualization can be achieved by constructing a digital 3D representation of the stratigraphic and structural geologic features. In this study, a 3D geologic model was created to better understand a karst aquifer system in the Buffalo National River watershed in northern Arkansas. The model was constructed based on data obtained from recent, detailed geologic mapping for the Hasty and Western Grove 7.5-minute quadrangles. The resulting model represents 11 stratigraphic zones of Ordovician, Mississippian, and Pennsylvanian age. As a result of the highly dissected topography, stratigraphic and structural control from geologic contacts and interpreted structure contours were sufficient for effectively modeling the faults and folds in the model area. Combined with recent dye-tracing studies, the 3D framework model is useful for visualizing the various geologic features and for analyzing the potential control they exert on the ground-water flow regime. Evaluation of the model, by comparison to published maps and cross-sections, indicates that the model accurately reproduces both the surface geology and subsurface geologic features of the area.

  17. Testing the usefulness of (222)Rn to complement conventional hydrochemical data to trace groundwater provenance in complex multi-layered aquifers. Application to the Úbeda aquifer system (Jaén, SE Spain).

    Science.gov (United States)

    Ortega, L; Manzano, M; Rodríguez-Arévalo, J

    2017-12-01

    The Úbeda aquifer system is a multi-layered aquifer intensively exploited for irrigation. It covers 1100km(2) and consists of piled up sedimentary aquifer and aquitard layers from Triassic sandstones and clays at the bottom, to Jurassic carbonates (main exploited layer) in the middle, and Miocene sandstones and marls at the top. Flow network modification by intense exploitation and the existence of deep faults favour vertical mixing of waters from different layers and with distinct chemical composition. This induces quality loss and fosters risk of quantity restrictions. To support future groundwater abstraction management, a hydrogeochemical (major and some minor solutes) and isotopic ((222)Rn) study was performed to identify the chemical signatures of the different layers and their mixing proportions in mixed samples. The study of 134 groundwater samples allowed a preliminary identification of hydrochemical signatures and mixtures, but the existence of reducing conditions in the most exploited sector prevents the utility of sulphate as a tracer of Triassic groundwater in the Jurassic boreholes. The potential of (222)Rn to establish isotopic signatures and to trace groundwater provenance in mixtures was tested. (222)Rn was measured in 48 samples from springs and boreholes in most aquifer layers. At first, clear correlations were observed between (222)Rn, Cl and SO4 in groundwater. Afterwards, very good correlations were observed between (222)Rn and the chemical facies of the different layers established with End Member Mixing Analysis (EMMA). Using (222)Rn as part of the signatures, EMMA helped to identify end-member samples, and to quantify the mixing proportions of water from the Triassic and the Deep Miocene layers in groundwater pumped by deep agricultural wells screened in the Jurassic. The incorporation of (222)Rn to the study also allowed identifying the impact of irrigation returns through the association of moderate NO3, Cl, and Br contents with very low

  18. 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.

  19. An expert system supporting decision making process for sustainable groundwater use in main alluvial aquifers in Slovenia

    Science.gov (United States)

    Souvent, Petra; Vižintin, Goran; Celarc, Sašo; Čenčur Curk, Barbara

    2016-04-01

    The expert decision support system for groundwater management in the shallow alluvial aquifers was developed to assist the decision makers to quantify available groundwater for a given alluvial aquifer and provide additional information about quantity of groundwater available for water rights licensing. The system links numerical groundwater flow models with the water permits and concessions databases in a complex decision support system. Six regional stand-alone groundwater models are used in the process of the assessment of groundwater quantitative status as well as for assessing availability of groundwater resources during the period of maximum water consumption and minimum groundwater recharge. Model runs have been realized in a steady state and are calibrated to a medium-low hydrological field conditions, because water quantities for all already granted as well as to-be granted water rights have to be ensured in any time for several years. The major goal of the expert decision support system is therefore to provide control mechanisms in order to verify the water rights licensing for the sustainable use of groundwater resources. The system enables that the water quantity data from water permits and concessions in conjunction with the results of numerical groundwater modeling are used in the managing process of granting new water rights to users in terms of their long-term access to groundwater (sufficient quantity of groundwater) and in relation to the water rights of other users (co-impact of groundwater pumping). Also, groundwater access must be managed in such a way that it does not cause unacceptable local impacts (pumping must not lower the water level for more than 2/3 of water body in the medium-low hydrological conditions).

  20. Geochemical and stable isotopic evolution of the Guarani Aquifer System in the state of São Paulo, Brazil

    Science.gov (United States)

    Sracek, Ondra; Hirata, Ricardo

    2002-09-01

    The purpose of this report is to explain geochemical and stable isotopes trends in the Brazilian unit of the Guarani Aquifer System (Botucatu and Piramboia aquifers) in São Paulo State, Brazil. Trends of dissolved species concentrations and geochemical modeling indicated a significant role of cation exchange and dissolution of carbonates in downgradient evolution of groundwater chemistry. Loss of calcium by the exchange for sodium drives dissolution of carbonates and results in Na-HCO3 type of groundwater. The cation-exchange front moves downgradient at probably much slower rate compared to the velocity of groundwater flow and at present is located near to the cities of Sertãozinho and Águas de Santa Barbara (wells PZ-34 and PZ-148, respectively) in a shallow confined area, 50-70 km from the recharge zone. Part of the sodium probably enters the Guarani Aquifer System. together with chloride and sulfate from the underlying Piramboia Formation by diffusion related to the dissolution of evaporates like halite and gypsum. High concentrations of fluorine (up to 13.3 mg/L) can be explained by dissolution of mineral fluoride also driven by cation exchange. However, it is unclear if the dissolution takes place directly in the Guarani Aquifer System or in the overlying basaltic Serra Geral Formation. There is depletion in δ2H and δ18O values in groundwater downgradient. Values of δ13C(DIC) are enriched downgradient, indicating dissolution of calcite under closed system conditions. Values of δ13C(DIC) in deep geothermal wells are very high (>-6.0‰) and probably indicate isotopic exchange with carbonates with δ13C about -3.0‰. Future work should be based on evaluation of vertical fluxes and potential for penetration of contamination to the Guarani Aquifer System. Résumé. Cet article a pour objet d'expliquer l'évolution de la géochimie et des isotopes stables dans l'unité brésilienne du système aquifère du Guarani (aquifères de Botucatu et Piramboia), dans

  1. Spatially distributed influence of agro-environmental factors governing nitrate fate and transport in an irrigated stream-aquifer system

    Science.gov (United States)

    Bailey, R. T.; Ahmadi, M.; Gates, T. K.; Arabi, M.

    2015-12-01

    Elevated levels of nitrate (NO3) in groundwater systems pose a serious risk to human populations and natural ecosystems. As part of an effort to remediate NO3 contamination in irrigated stream-aquifer systems, this study elucidates agricultural and environmental parameters and processes that govern NO3 fate and transport at the regional (500 km2), local (50 km2), and field scales (humus decomposition also dominate or partially dominate in other locations. Each factor, with the exception of O2 reduction rate, is the dominating influence on NO3 groundwater concentration at one or more locations within the study area. Results can be used to determine critical processes and key management actions for future data collection and remediation strategies, with efforts able to be focused on localized areas.

  2. Sandy River Delta Habitat Restoration Project, Annual Report 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Virginia; Dobson, Robin L.

    2002-11-01

    The Sandy River Delta is located at the confluence of the Sandy and Columbia Rivers, just east of Troutdale, Oregon. It comprises about 1,400 land acres north of Interstate 84, managed by the USDA Forest Service, and associated river banks managed by the Oregon Division of State Lands. Three islands, Gary, Flag and Catham, managed by Metro Greenspaces and the State of Oregon lie to the east, the Columbia River lies to the north and east, and the urbanized Portland metropolitan area lies to the west across the Sandy River. Sandy River Delta was historically a wooded, riparian wetland with components of ponds, sloughs, bottomland woodland, oak woodland, prairie, and low and high elevation floodplain. It has been greatly altered by past agricultural practices and the Columbia River hydropower system. Restoration of historic landscape components is a primary goal for this land. The Forest Service is currently focusing on restoration of riparian forest and wetlands. Restoration of open upland areas (meadow/prairie) would follow substantial completion of the riparian and wetland restoration. The Sandy River Delta is a former pasture infested with reed canary grass, blackberry and thistle. The limited over story is native riparian species such as cottonwood and ash. The shrub and herbaceous layers are almost entirely non-native, invasive species. Native species have a difficult time naturally regenerating in the thick, competing reed canary grass, Himalayan blackberry and thistle. A system of drainage ditches installed by past owners drains water from historic wetlands. The original channel of the Sandy River was diked in the 1930's, and the river diverted into the ''Little Sandy River''. The original Sandy River channel has subsequently filled in and largely become a slough. The FS acquired approximately 1,400 acres Sandy River Delta (SRD) in 1991 from Reynolds Aluminum (via the Trust for Public Lands). The Delta had been grazed for many years

  3. The origin of increased salinity in the Cambrian-Vendian aquifer system on the Kopli Peninsula, northern Estonia

    Science.gov (United States)

    Karro, Enn; Marandi, Andres; Vaikmäe, Rein

    Monitoring of the confined Cambrian-Vendian aquifer system utilised for industrial water supply at Kopli Peninsula in Tallinn over 24 years reveals remarkable changes in chemical composition of groundwater. A relatively fast 1.5 to 3.0-fold increase in TDS and in concentrations of major ions in ed groundwater is the consequence of heavy pumping. The main sources of dissolved load in Cambrian-Vendian groundwater are the leaching of host rock and the other geochemical processes that occur in the saturated zone. Underlying crystalline basement, which comprises saline groundwater in its upper weathered and fissured portion, and which is hydraulically connected with the overlying Cambrian-Vendian aquifer system, is the second important source of ions. The fractured basement and its clayey weathering crust host the Ca-Cl type groundwater, which is characterised by high TDS values (2-20 g/L). Intensive water ion accelerates the exchange of groundwaters and increases the area of influence of pumping. Chemical and isotopic studies of groundwater indicate an increasing contribution of old brackish water from the crystalline basement and rule out the potential implication of an intrusion of seawater into aquifer. L'origine de la salinité croissante dans le système aquifère du Cambrien-Vendien dans la péninsule de Kopli, nord de l'Estonie Le suivi à long terme du système aquifère captif du Cambrien-Vendien utilisé pour l'approvisionnement d'eaux industrielles dans la Péninsule de Kopli, nord de l'Estonie, révèle de remarquables changements dans la composition chimique des eaux souterraines. Une augmentation de facteur 1.5 à 3 de la TDS et des concentrations en ions majeurs dans l'eau souterraine est la conséquence de pompages intensifs. Les sources principales des charges dissoutes dans les eaux de l'aquifère du Cambrien-Vendien sont le lessivage des roches et d'autres phénomènes géochimiques ayant lieu dans la zone saturée. Le soubassement rocheux cristallin

  4. Modelling as a means to promote water diplomacy in Southern Africa: the Stampriet Transboundary Aquifer System case study

    Science.gov (United States)

    De Filippis, Giovanna; Carvalho Resende, Tales; Filali-Meknassi, Youssef; Puri, Shaminder; Kenabatho, Piet; Amakali, Maria; Majola, Kwazikwakhe; Rossetto, Rudy

    2017-04-01

    Within the framework of the "Governance of Groundwater Resources in Transboundary Aquifers" (GGRETA) project, funded by the Swiss Agency for Development and Cooperation (SDC), the Governments of Botswana, Namibia and South Africa, jointly with the UNESCO International Hydrological Programme (UNESCO-IHP) are undertaking an assessment of the Stampriet Transboundary Aquifer System (STAS). The importance of the STAS to the region draws from the fact that it is the only permanent and dependable water resource in the area, which covers 87000 km2 from Central Namibia into Western Botswana and South Africa's Northern Cape Province. The first phase of the project (2013-2015) focused on an assessment of the STAS which allowed establishing a shared science based understanding of the resource. The activities of the second phase of the project (2016-2018) will consolidate the technical results achieved and the tools developed in the first phase, and will strengthen capacity on groundwater governance at the national and transboundary levels to support the process of establishment of a multi-country cooperation mechanism (MCCM). The establishment of the STAS MCCM would be the first example of a mechanism for the management and governance of a transboundary aquifer in Southern Africa. The joint development of a numerical model is crucial to foster such cooperation as it provides a baseline for the formulation of sound policies for the governance of the STAS. The model is being developed through the application of the FREEWAT platform (within the H2020 FREEWAT project - FREE and open source software tools for WATer resource management; Rossetto et al., 2015), an open source and public domain GIS-integrated modelling environment for the simulation of the hydrological cycle. The FREEWAT project aims at improving water resource management by simplifying the application of water-related regulations through the use of modeling environments and GIS tools for storage, management and

  5. Hydrogeologic characteristics and water quality of a confined sand unit in the surficial aquifer system, Hunter Army Airfield, Chatham County, Georgia

    Science.gov (United States)

    Gonthier, Gerard J.

    2012-01-01

    An 80-foot-deep well (36Q397, U.S. Geological Survey site identification 320146081073701) was constructed at Hunter Army Airfield to assess the potential of using the surficial aquifer system as a water source to irrigate a ballfield complex. A 300-foot-deep test hole was drilled beneath the ballfield complex to characterize the lithology and water-bearing characteristics of sediments above the Upper Floridan aquifer. The test hole was then completed as well 36Q397 open to a 19-foot-thick shallow, confined sand unit contained within the surficial aquifer system. A single-well, 24-hour aquifer test was performed by pumping well 36Q397 at a rate of 50 gallons per minute during July 13-14, 2011, to characterize the hydrologic properties of the shallow, confined sand unit. Two pumping events prior to the aquifer test affected water levels. Drawdown during all three pumping events and residual drawdown during recovery periods were simulated using the Theis formula on multiple changes in discharge rate. Simulated drawdown and residual drawdown match well with measured drawdown and residual drawdown using values of horizontal hydraulic conductivity and specific storage, which are typical for a confined sand aquifer. Based on the hydrologic parameters used to match simulated drawdown and residual drawdown to measured drawdown and residual drawdown, the transmissivity of the sand was determined to be about 400 feet squared per day. The horizontal hydraulic conductivity of the sand was determined to be about 20 feet per day. Analysis of a water-quality sample indicated that the water is suitable for irrigation. Sample analysis indicated a calcium-carbonate type water having a total dissolved solids concentration of 39 milligrams per liter. Specific conductance and concentrations of all analyzed constituents were below those that would be a concern for irrigation, and were below primary and secondary water-quality criteria levels.

  6. Nitrate leaching to groundwater at experimental farm "De Marke" and other Dutch sandy soils

    NARCIS (Netherlands)

    Hack-ten Broeke, M.J.D.

    2001-01-01

    This study focuses on nitrate leaching to the groundwater as a result of the land use system of experimental farm 'De Marke', translated to other sandy soils in the Netherlands. The land use was extrapolated to five major sandy soil map units, selected from the 1: 50 000 Soil Map of the Netherlands,

  7. Potential for isoproturon, atrazine and mecoprop to be degraded within a chalk aquifer system

    Science.gov (United States)

    Johnson, Andrew C.; White, Craig; Lal Bhardwaj, C.

    2000-06-01

    The potential for herbicide degradation in an unconfined chalk aquifer was examined by collecting and spiking fresh samples and incubating them in the laboratory. The microcosms were incubated at 20°C under aerobic conditions and spiked with either isoproturon, atrazine or mecoprop at a concentration of 100 μg/l. The samples were obtained from a single fieldsite within the Upper Chalk aquifer in Hampshire, UK. Groundwater samples required the presence of sterile chalk in a ratio of at least 1:13 to promote isoproturon degradation. An isoproturon degradation potential existed in the soil, and the chalk unsaturated and saturated zones. However, no degradation of isoproturon in the unsaturated zone was observed when a more appropriate simulation of in-situ moisture conditions was carried out. Apart from the soil, no potential for atrazine or mecoprop degradation could be detected in the same samples over a 200-day incubation. In a series of groundwater samples taken from different boreholes, 10-300 m apart, large differences in isoproturon degradation potential were observed. Removal rates for 100 μg/l isoproturon varied from 83-425 ng/day, but in some samples no degradation potential could be detected. The primary metabolite which could be distinguished from isoproturon degradation in chalk and groundwater was monodesmethyl-isoproturon. When a chalk groundwater sample was spiked with isoproturon at 0.9 μg/l, this was not degraded over a 300-day incubation period. Further experiments with fresh groundwater from a Triassic Sandstone site illustrated that groundwater bacteria could degrade isoproturon at the more realistic temperature of 10°C as well as at 20°C.

  8. Study of the Santa Catarina aquifer system (Mexico Basin) using magnetotelluric soundings

    Science.gov (United States)

    Chouteau, Michel; Krivochieva, Stefka; Castillo, Ramiro Rodriguez; Moran, Tomas Gonzalez; Jouanne, Virginie

    1994-02-01

    A tensor magnetotelluric test survey was carried out in the region of Santa Catarina, located in the Chalco sub-basin of the Mexico Basin. The objective was to define the stratification at depth with an emphasis on the geometry of the main aquifer of that region which is partially known from DC resistivity soundings and drilling. High-quality magnetotelluric soundings could be recorded in the immediate vicinity of large urban zones because the sub-surface is very conductive. Interpretation shows that the solid bedrock is located at a depth of at least 800 m to the south and 1300 m to the north; it could, however, be much deeper. Using complementary DC resistivity sounding and well-logging data, three main layers have been defined overlying the bedrock. These layers are, from surface to bottom, an unsaturated zone of sand, volcanic ash and clay about 10 m thick, followed by a very conductive (1.5 ohm·m) 200 m thick layer of sand and ash with intercalated clay, saturated with highly mineralized water, and finally a zone with resistivity increasing gradually to 60 ohm·m. The investigated deep aquifer constitutes most of this third layer. It consists of a sequence of sand, gravel, pyroclastites and mainly fractured basalts. MT resistivity soundings and magnetic transfer functions also indicate that a shallow resistive structure is dipping, from the northwest, into the lacustrine deposits of the basin. This geologic feature is likely to be highly permeable fractured basaltic flows, which provide a channel by which water contaminated by the Santa Catarina landfill may leak into the basin.

  9. Threats to sandy beach ecosystems: A review

    Science.gov (United States)

    Defeo, Omar; McLachlan, Anton; Schoeman, David S.; Schlacher, Thomas A.; Dugan, Jenifer; Jones, Alan; Lastra, Mariano; Scapini, Felicita

    2009-01-01

    We provide a brief synopsis of the unique physical and ecological attributes of sandy beach ecosystems and review the main anthropogenic pressures acting on the world's single largest type of open shoreline. Threats to beaches arise from a range of stressors which span a spectrum of impact scales from localised effects (e.g. trampling) to a truly global reach (e.g. sea-level rise). These pressures act at multiple temporal and spatial scales, translating into ecological impacts that are manifested across several dimensions in time and space so that today almost every beach on every coastline is threatened by human activities. Press disturbances (whatever the impact source involved) are becoming increasingly common, operating on time scales of years to decades. However, long-term data sets that describe either the natural dynamics of beach systems or the human impacts on beaches are scarce and fragmentary. A top priority is to implement long-term field experiments and monitoring programmes that quantify the dynamics of key ecological attributes on sandy beaches. Because of the inertia associated with global climate change and human population growth, no realistic management scenario will alleviate these threats in the short term. The immediate priority is to avoid further development of coastal areas likely to be directly impacted by retreating shorelines. There is also scope for improvement in experimental design to better distinguish natural variability from anthropogenic impacts. Sea-level rise and other effects of global warming are expected to intensify other anthropogenic pressures, and could cause unprecedented ecological impacts. The definition of the relevant scales of analysis, which will vary according to the magnitude of the impact and the organisational level under analysis, and the recognition of a physical-biological coupling at different scales, should be included in approaches to quantify impacts. Zoning strategies and marine reserves, which have not

  10. Characterisation of Seasonal Temperature Variation in a Shallow, Urban Aquifer: Implications for the Sustainable Development of Ground Source Heating Systems

    Science.gov (United States)

    Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.

    2017-04-01

    Groundwater thermally enhanced by the Urban Heat Island effect can be utilised by ground source heating systems (GSHSs). However, the near subsurface is subject to seasonal temperature variation reflected in shallow groundwater that can differ by several degrees throughout the year. To sustainably manage the near surface thermal resource an understanding of factors which control variation in groundwater temperature and how these are transmitted through the aquifer is needed. We show that even in relatively small urban areas (Cardiff, U.K., situated on a shallow gravel aquifer) the Zone of Seasonal Fluctuation (ZSF) can vary in depth by 8m. GSHSs are more efficient if they are sited below the ZSF, where temperatures are more stable. In Spring 2014, 48 groundwater monitoring boreholes were profiled at a 1m resolution to measure groundwater temperature across Cardiff. These were reprofiled that Autumn and compared to the Spring temperatures, defining the ZSF. The average depth to the base of the ZSF was 9.5mbgl but ranged from 7.1-15.5mbgl. The amplitude of the differences between Spring and Autumn temperatures also varied. To better understand the high spatial variability 60 boreholes were instrumented with in situ temperature loggers, recording at half-hourly intervals. The first year's data revealed the amplitudes of temperature variation within boreholes with loggers at similar depths were not always consistent. It was also noted that lag times between air temperature and groundwater temperature were not uniform across the sites. The data also showed that where gravels occurred at shallower depths the ZSF tended to be shallower and lag times shorter. The wide spatial variability of the ZSF may be partially explained by differing landuse. Those boreholes in open, grassed areas showed a deeper ZSF than those in built-up areas but built-up areas generally showed the greatest variation between Spring and Autumn temperature profiles, suggesting heat loss from buildings

  11. Identifying microbial carbon sources during ethanol and toluene biodegradation in a pilot-scale experimental aquifer system using isotopic analysis

    Science.gov (United States)

    Clay, S.; McLeod, H.; Smith, J. E.; Roy, J. W.; Slater, G. F.

    2013-12-01

    Combining ethanol with gasoline has become increasingly common in order to create more environmentally conscience transportation fuels. These blended fuels are favourable alternatives since ethanol is a non-toxic and highly labile renewable biomass-based resource which is an effective fuel oxygenate that reduces air pollution. Recent research however, has indicated that upon accidental release into groundwater systems, the preferential microbial metabolism of ethanol can cause progressively reducing conditions leading to slower biodegradation of petroleum hydrocarbons. Therefore, the presence of ethanol can result in greater persistence of BTEX compounds and longer hydrocarbon plumes in groundwater systems. Microbial biodegradation and community carbon sources coupled to aqueous geochemistry were monitored in a pilot-scale laboratory tank (80cm x 525cm x 175cm) simulating an unconfined sand aquifer. Dissolved ethanol and toluene were continuously injected into the aquifer at a controlled rate over 330 days. Carbon isotope analyses were performed on phospholipid fatty acid (PLFA) samples collected from 4 different locations along the aquifer. Initial stable carbon isotope values measured over days 160-185 in the bacterial PLFA ranged from δ13C = -10 to -21‰, which is indicative of dominant ethanol incorporation by the micro-organisms based on the isotopic signature of ethanol derived from corn, a C4 plant. A negative shift to δ13C = -10 to -30‰ observed over days 185-200, suggests a change in microbial metabolisms associated with less ethanol incorporation. This generally corresponds to a decrease in ethanol concentrations from day 40 to full attenuation at approximately day 160, and the onset of toluene depletion observed on day 120 and continuing thereafter. In addition, aqueous methane concentrations first detected on day 115 continued to rise to 0.38-0.70 mmol/L at all monitoring locations, demonstrating a significant redox shift to low energy methanogenic

  12. The use of salinity contrast for density difference compensation to improve the thermal recovery efficiency in high-temperature aquifer thermal energy storage systems

    NARCIS (Netherlands)

    van Lopik, J.H.; Hartog, N.; Zaadnoordijk, Willem Jan

    2016-01-01

    The efficiency of heat recovery in high-temperature (>60 °C) aquifer thermal energy storage (HT-ATES) systems is limited due to the buoyancy of the injected hot water. This study investigates the potential to improve the efficiency through compensation of the density difference by increased salinity

  13. Occurrence and geochemistry of radium in water from principal drinking-water aquifer systems of the United States

    Science.gov (United States)

    Szabo, Z.; dePaul, V.T.; Fischer, J.M.; Kraemer, T.F.; Jacobsen, E.

    2012-01-01

    A total of 1270 raw-water samples (before treatment) were collected from 15 principal and other major aquifer systems (PAs) used for drinking water in 45 states in all major physiographic provinces of the USA and analyzed for concentrations of the Ra isotopes 224Ra, 226Ra and 228Ra establishing the framework for evaluating Ra occurrence. The US Environmental Protection Agency Maximum Contaminant Level (MCL) of 0.185Bq/L (5pCi/L) for combined Ra ( 226Ra plus 228Ra) for drinking water was exceeded in 4.02% (39 of 971) of samples for which both 226Ra and 228Ra were determined, or in 3.15% (40 of 1266) of the samples in which at least one isotope concentration ( 226Ra or 228Ra) was determined. The maximum concentration of combined Ra was 0.755Bq/L (20.4pCi/L) in water from the North Atlantic Coastal Plain quartzose sand aquifer system. All the exceedences of the MCL for combined Ra occurred in water samples from the following 7PAs (in order of decreasing relative frequency of occurrence): the Midcontinent and Ozark Plateau Cambro-Ordovician dolomites and sandstones, the North Atlantic Coastal Plain, the Floridan, the crystalline rocks (granitic, metamorphic) of New England, the Mesozoic basins of the Appalachian Piedmont, the Gulf Coastal Plain, and the glacial sands and gravels (highest concentrations in New England).The concentration of Ra was consistently controlled by geochemical properties of the aquifer systems, with the highest concentrations most likely to be present where, as a consequence of the geochemical environment, adsorption of the Ra was slightly decreased. The result is a slight relative increase in Ra mobility, especially notable in aquifers with poor sorptive capacity (Fe-oxide-poor quartzose sands and carbonates), even if Ra is not abundant in the aquifer solids. The most common occurrence of elevated Ra throughout the USA occurred in anoxic water (low dissolved-O 2) with high concentrations of Fe or Mn, and in places, high concentrations of the

  14. Hydrologic conditions, recharge, and baseline water quality of the surficial aquifer system at Jekyll Island, Georgia, 2012-13

    Science.gov (United States)

    Gordon, Debbie W.; Torak, Lynn J.

    2016-03-08

    An increase of groundwater withdrawals from the surficial aquifer system on Jekyll Island, Georgia, prompted an investigation of hydrologic conditions and water quality by the U.S. Geological Survey during October 2012 through December 2013. The study demonstrated the importance of rainfall as the island’s main source of recharge to maintain freshwater resources by replenishing the water table from the effects of hydrologic stresses, primarily evapotranspiration and pumping. Groundwater-flow directions, recharge, and water quality of the water-table zone on the island were investigated by installing 26 shallow wells and three pond staff gages to monitor groundwater levels and water quality in the water-table zone. Climatic data from Brunswick, Georgia, were used to calculate potential maximum recharge to the water-table zone on Jekyll Island. A weather station located on the island provided only precipitation data. Additional meteorological data from the island would enhance potential evapotranspiration estimates for recharge calculations.

  15. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Point features used for the top of the regional middle confining unit (base of Upper Floridan aquifer)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  16. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Point features used for the top of the regional middle confining unit (base of Upper Floridan aquifer), constrained

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  17. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the top of the regional middle confining unit (base of Upper Floridan aquifer)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  18. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Well locations used in the development of the potentiometric surface map for the Upper Floridan aquifer in May 2010

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  19. New distributional records of the stygobitic crayfish Cambarus cryptodytes (Decapoda: Cambaridae) in the Floridan Aquifer System of southwestern Georgia

    Science.gov (United States)

    Fenolio, Dante B.; Niemiller, Matthew L.; Gluesenkamp, Andrew G.; Mckee, Anna; Taylor, Steven J.

    2017-01-01

    Cambarus cryptodytes (Dougherty Plain Cave Crayfish) is an obligate inhabitant of groundwater habitats (i.e., a stygobiont) with troglomorphic adaptations in the Floridan aquifer system of southwestern Georgia and adjacent Florida panhandle, particularly in the Dougherty Plain and Marianna Lowlands. Documented occurrences of Dougherty Plain Cave Crayfish are spatially distributed as 2 primary clusters separated by a region where few caves and springs have been documented; however, the paucity of humanly accessible karst features in this intermediate region has inhibited investigation of the species' distribution. To work around this constraint, we employed bottle traps to sample for Dougherty Plain Cave Crayfish and other groundwater fauna in 18 groundwater-monitoring wells that access the Floridan aquifer system in 10 counties in southwestern Georgia. We captured 32 Dougherty Plain Cave Crayfish in 9 wells in 8 counties between September 2014 and August 2015. We detected crayfish at depths ranging from 17.9 m to 40.6 m, and established new county records for Early, Miller, Mitchell, and Seminole counties in Georgia, increasing the number of occurrences in Georgia from 8 to 17 sites. In addition, a new US Geological Survey (USGS) Hydrologic Unit Code 8 (HUC8) watershed record was established for the Spring Creek watershed. These new records fill in the distribution gap between the 2 previously known clusters in Georgia and Jackson County, FL. Furthermore, this study demonstrates that deployment of bottle traps in groundwater-monitoring wells can be an effective approach to presence—absence surveys of stygobionts, especially in areas where surface access to groundwater is limited.

  20. The ESPAT tool: a general-purpose DSS shell for solving stochastic optimization problems in complex river-aquifer systems

    Science.gov (United States)

    Macian-Sorribes, Hector; Pulido-Velazquez, Manuel; Tilmant, Amaury

    2015-04-01

    Stochastic programming methods are better suited to deal with the inherent uncertainty of inflow time series in water resource management. However, one of the most important hurdles in their use in practical implementations is the lack of generalized Decision Support System (DSS) shells, usually based on a deterministic approach. The purpose of this contribution is to present a general-purpose DSS shell, named Explicit Stochastic Programming Advanced Tool (ESPAT), able to build and solve stochastic programming problems for most water resource systems. It implements a hydro-economic approach, optimizing the total system benefits as the sum of the benefits obtained by each user. It has been coded using GAMS, and implements a Microsoft Excel interface with a GAMS-Excel link that allows the user to introduce the required data and recover the results. Therefore, no GAMS skills are required to run the program. The tool is divided into four modules according to its capabilities: 1) the ESPATR module, which performs stochastic optimization procedures in surface water systems using a Stochastic Dual Dynamic Programming (SDDP) approach; 2) the ESPAT_RA module, which optimizes coupled surface-groundwater systems using a modified SDDP approach; 3) the ESPAT_SDP module, capable of performing stochastic optimization procedures in small-size surface systems using a standard SDP approach; and 4) the ESPAT_DET module, which implements a deterministic programming procedure using non-linear programming, able to solve deterministic optimization problems in complex surface-groundwater river basins. The case study of the Mijares river basin (Spain) is used to illustrate the method. It consists in two reservoirs in series, one aquifer and four agricultural demand sites currently managed using historical (XIV century) rights, which give priority to the most traditional irrigation district over the XX century agricultural developments. Its size makes it possible to use either the SDP or

  1. 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.

  2. An analytical model for flow induced by a constant-head pumping in a leaky unconfined aquifer system with considering unsaturated flow

    Science.gov (United States)

    Lin, Ye-Chen; Li, Ming-Hsu; Yeh, Hund-Der

    2017-09-01

    A new mathematical model is developed to describe the flow in response to a constant-head pumping (or constant-head test, CHT) in a leaky unconfined aquifer system of infinite lateral extent with considering unsaturated flow. The model consists of an unsaturated zone on the top, an unconfined aquifer in the middle, and a second aquifer (aquitard) at the bottom. The unsaturated flow is described by Richard's equation, and the flows in unconfined aquifer and second layer are governed by the groundwater flow equation. The well partially penetrates the unconfined aquifer with a constant head in the well due to CHT. The governing equations of the model are linearized by the perturbation method and Gardner's exponential model is adopted to describe the soil retention curves. The solution of the model for drawdown distribution is obtained by applying the methods of Laplace transform and Weber transform. Then the solution for the wellbore flowrate is derived from the drawdown solution with Darcy's law. The issue of the equivalence of normalized drawdown predicted by the present solution for constant-head pumping and Tartakovsky and Neuman's (2007) solution for constant-rate pumping is discussed. On the basis of the wellbore flowrate solution, the results of the sensitivity analysis indicate that the wellbore flowrate is very sensitive to the changes in the radial hydraulic conductivity and the thickness of the saturated zone. Moreover, the results predicted from the present wellbore flowrate solution indicate that this new solution can reduce to Chang's et al. (2010a) solution for homogenous aquifers when the dimensionless unsaturated exponent approaches 100. The unsaturated zone can be considered as infinite extent in the vertical direction if the thickness ratio of the unsaturated zone to the unconfined aquifer is equal to or greater than one. As for the leakage effect, it can be ignored when the vertical hydraulic conductivity ratio (i.e., the vertical hydraulic

  3. Estimating Hydraulic Properties of the Floridan Aquifer System by Analysis of Earth-Tide, Ocean-Tide, and Barometric Effects, Collier and Hendry Counties, Florida

    Science.gov (United States)

    Merritt, Michael L.

    2004-01-01

    time-varying drawdown in an open well with periodic pressure-head oscillations in the aquifer, but the applicability of such methods might be limited in studies of the Floridan aquifer system.

  4. Geological exploration for a high-temperature aquifer thermal energy storage (HT-ATES) system: a case study from Oman

    Science.gov (United States)

    Winterleitner, Gerd; Schütz, Felina; Huenges, Ernst

    2017-04-01

    A collaborative research programme between the German Research Centre for Geoscience, Potsdam (GFZ) and The Research Council of Oman (TRC) is underway, which aims to develop and implement an innovative concept of a sustainable thermally driven cooling system in combination with a HT-ATES in northern Oman. The system will use an absorption chiller for cold supply, which nominally requires water of around 100°C as energy source. Solar collectors will provide this thermal energy and energy surpluses during daytimes will be stored to ensure a continuous operation of the cooling system. An integral part of this project is, therefore, the development of an efficient HT-ATES (100°C), which is based on temporary storage and recovery of thermal energy through hot water injection in subsurface aquifer horizons. Thus, an accurate thermal and fluid flow characterisation of potential reservoir horizons is essential to ensure optimal efficiency of the cooling system. The study area is located in the Al Khwad area, approximately 40 km to the west of Muscat. The area is characterised by a thick Cenozoic mixed carbonate-siliciclastic sedimentary succession, containing at least 3 aquifer horizons. We use a multidisciplinary approach for the initial ATES exploration and development phase, including traditional geological fieldwork dovetailed with virtual outcrop geology, thin-section analyses, geological modelling and reservoir fluid flow forecasting analyses. Our first results indicate two potential storage horizons: (1) a Miocene-aged clastic-dominated alluvial fan system and (2) an Eocene carbonate-dominated sequence. The alluvial fan system is characterised by a more than 300 m thick, coarse-clastic succession of coalesced individual fans. Thermal and hydraulic parameters are favourable for gravel and sandstone intervals but reservoir architecture is complex due to multiple generations of interconnecting fans with highly heterogeneous facies distributions. The Eocene carbonates

  5. Hydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin

    Science.gov (United States)

    Bartos, Timothy T.; Hallberg, Laura L.; Miller, Cheryl E.

    2015-07-14

    In cooperation with the Bureau of Land Management, groundwater levels in wells located in the northern Green River Basin in Wyoming, an area of ongoing energy development, were measured by the U.S. Geological Survey from 2010 to 2014. The wells were completed in the uppermost aquifers of the Green River Basin lower Tertiary aquifer system, which is a complex regional aquifer system that provides water to most wells in the area. Except for near perennial streams, groundwater-level altitudes in most aquifers generally decreased with increasing depth, indicating a general downward potential for groundwater movement in the study area. Drilled depth of the wells was observed as a useful indicator of depth to groundwater such that deeper wells typically had a greater depth to groundwater. Comparison of a subset of wells included in this study that had historical groundwater levels that were measured during the 1960s and 1970s and again between 2012 and 2014 indicated that, overall, most of the wells showed a net decline in groundwater levels.

  6. Occurrence of Pepper Mild Mottle Virus (PMMoV) in Groundwater from a Karst Aquifer System in the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Rosiles-González, Gabriela; Ávila-Torres, Gerardo; Moreno-Valenzuela, Oscar A; Acosta-González, Gilberto; Leal-Bautista, Rosa María; Grimaldo-Hernández, Cinthya D; Brown, Judith K; Chaidez-Quiroz, Cristóbal; Betancourt, Walter Q; Gerba, Charles P; Hernández-Zepeda, Cecilia

    2017-06-23

    The Yucatan Peninsula of Mexico hosts a karst aquifer system that is the only source of freshwater for the area; however, it is vulnerable to human-mediated contamination. Pepper mild mottle virus (PMMoV) is one of the most abundant RNA viruses associated with human feces, making it a viable indicator for tracking fecal pollution in aquatic environments, including groundwater. In this study, groundwater samples collected from a karst aquifer from fresh and brackish water locations were analyzed for fecal indicator bacteria, somatic and male F+ specific coliphages, and PMMoV during the rainy and dry seasons. Total coliform bacteria were detected at all sites, whereas Escherichia coli were found at relatively low levels water type (p > 0.05). Physicochemical and indicator bacteria were not correlated with PMMoV concentrations. The abundance and prevalence of PMMoV in the karst aquifer may reflect its environmental persistence and its potential as a fecal indicator in this karst aquifer system.

  7. Occurrence and Distribution of Iron, Manganese, and Selected Trace Elements in Ground Water in the Glacial Aquifer System of the Northern United States

    Science.gov (United States)

    Groschen, George E.; Arnold, Terri L.; Morrow, William S.; Warner, Kelly L.

    2009-01-01

    Dissolved trace elements, including iron and manganese, are often an important factor in use of ground water for drinking-water supplies in the glacial aquifer system of the United States. The glacial aquifer system underlies most of New England, extends through the Midwest, and underlies portions of the Pacific Northwest and Alaska. Concentrations of dissolved trace elements in ground water can vary over several orders of magnitude across local well networks as well as across regions of the United States. Characterization of this variability is a step toward a regional screening-level assessment of potential human-health implications. Ground-water sampling, from 1991 through 2003, of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey determined trace element concentrations in water from 847 wells in the glacial aquifer system. Dissolved iron and manganese concentrations were analyzed in those well samples and in water from an additional 743 NAWQA land-use and major-aquifer survey wells. The samples are from monitoring and water-supply wells. Concentrations of antimony, barium, beryllium, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, selenium, strontium, thallium, uranium, and zinc vary as much within NAWQA study units (local scale; ranging in size from a few thousand to tens of thousands of square miles) as over the entire glacial aquifer system. Patterns of trace element concentrations in glacial aquifer system ground water were examined by using techniques suitable for a dataset with zero to 80 percent of analytical results reported as below detection. During the period of sampling, the analytical techniques changed, which generally improved the analytical sensitivity. Multiple reporting limits complicated the comparison of detections and concentrations. Regression on Order Statistics was used to model probability distributions and estimate the medians and other quantiles of the trace element

  8. A System Dynamics Model to Conserve Arid Region Water Resources through Aquifer Storage and Recovery in Conjunction with a Dam

    Directory of Open Access Journals (Sweden)

    Amir Niazi

    2014-08-01

    Full Text Available Groundwater depletion poses a significant threat in arid and semi-arid areas where rivers are usually ephemeral and groundwater is the major source of water. The present study investigated whether an effective water resources management strategy, capable of minimizing evaporative water losses and groundwater depletion while providing water for expanded agricultural activities, can be achieved through aquifer storage and recovery (ASR implemented in conjunction with water storage in an ephemeral river. A regional development modeling framework, including both ASR and a dam design developed through system dynamics modeling, was validated using a case study for the Sirik region of Iran. The system dynamics model of groundwater flow and the comprehensive system dynamics model developed in this study showed that ASR was a beneficial strategy for the region’s farmers and the groundwater system, since the rate of groundwater depletion declined significantly (from 14.5 meters per 40 years to three meters over the same period. Furthermore, evaporation from the reservoir decreased by 50 million cubic meters over the simulation period. It was concluded that the proposed system dynamics model is an effective tool in helping to conserve water resources and reduce depletion in arid regions and semi-arid areas.

  9. Mobility and Fate of Pollutants in the Aquifer System of the Northwestern Suez Gulf, Egypt.

    Science.gov (United States)

    Snousy, Moustafa Gamal; Zawrah, M F; Abdel-Moghny, Th; Ebiad, M A; Rashad, A M; Khalil, Mahmoud M; Abu El Ella, E M; El-Sayed, E; Tantawy, M A

    The northwestern part of Suez Gulf region is a strategic area in Egypt. It includes important sources of national income. To achieve the development goals, the government has established huge projects in this area (e.g. establishment and expanding of a large commercial port at Ain Sokhna, many industrial zones as well as tourism projects). The utilization of the Suez Gulf resources and their continuing development mainly depend on the creation of actual pollution control programs. The environmental quality control and pollution reduction activities are important ingredients of any economic development program. These different activities in this area depend mainly on the groundwater that is pumped intensively from different water bearing formations or aquifers. The main objective of the present work is compiling the previous studies from the 1980s up to 2015. These studies are concerned with estimating the concentrations of different pollutants in various ecosystems in the northwestern Suez Gulf region. Also, to provide an explanation for the movement of different pollutants such as organic and heavy metals from contaminated land to ground and surface (Gulf) waters. This issue has not been extensively surveyed before, and this review, gives specific directions for future monitoring and remediation strategies in this region.

  10. Vulnerability of deep groundwater in the Bengal Aquifer System to contamination by arsenic

    Science.gov (United States)

    Burgess, W.G.; Hoque, M.A.; Michael, H.A.; Voss, C.I.; Breit, G.N.; Ahmed, K.M.

    2010-01-01

    Shallow groundwater, the primary water source in the Bengal Basin, contains up to 100 times the World Health Organization (WHO) drinking-water guideline of 10g l 1 arsenic (As), threatening the health of 70 million people. Groundwater from a depth greater than 150m, which almost uniformly meets the WHO guideline, has become the preferred alternative source. The vulnerability of deep wells to contamination by As is governed by the geometry of induced groundwater flow paths and the geochemical conditions encountered between the shallow and deep regions of the aquifer. Stratification of flow separates deep groundwater from shallow sources of As in some areas. Oxidized sediments also protect deep groundwater through the ability of ferric oxyhydroxides to adsorb As. Basin-scale groundwater flow modelling suggests that, over large regions, deep hand-pumped wells for domestic supply may be secure against As invasion for hundreds of years. By contrast, widespread deep irrigation pumping might effectively eliminate deep groundwater as an As-free resource within decades. Finer-scale models, incorporating spatial heterogeneity, are needed to investigate the security of deep municipal abstraction at specific urban locations. ?? 2010 Macmillan Publishers Limited. All rights reserved.

  11. Assessing the Vulnerability of Public-Supply Wells to Contamination: Central Valley Aquifer System near Modesto, California

    Science.gov (United States)

    Jagucki, Martha L.; Jurgens, Bryant C.; Burow, Karen R.; Eberts, Sandra M.

    2009-01-01

    This fact sheet highlights findings from the vulnerability study of a public-supply well in Modesto, California. The well selected for study pumps on average about 1,600 gallons per minute from the Central Valley aquifer system during peak summer demand. Water samples were collected at the public-supply well and at monitoring wells installed in the Modesto vicinity. Samples from the public-supply wellhead contained the undesirable constituents uranium, nitrate, arsenic, volatile organic compounds (VOCs), and pesticides, although none were present at concentrations exceeding drinking-water standards. Of these contaminants, uranium and nitrate pose the most significant water-quality risk to the public-supply well because human activities have caused concentrations in groundwater to increase over time. Overall, study findings point to four primary factors that affect the movement and (or) fate of contaminants and the vulnerability of the public-supply well in Modesto: (1) groundwater age (how long ago water entered, or recharged, the aquifer); (2) irrigation and agricultural and municipal pumping that drives contaminants downward into the primary production zone of the aquifer; (3) short-circuiting of contaminated water down the public-supply well during the low-pumping season; and (4) natural geochemical conditions of the aquifer. A local-scale computer model of groundwater flow and transport to the public-supply well was constructed to simulate long-term nitrate and uranium concentrations reaching the well. With regard to nitrate, two conflicting processes influence concentrations in the area contributing recharge to the well: (1) Beneath land that is being farmed or has recently been farmed (within the last 10 to 20 years), downward-moving irrigation waters contain elevated nitrate concentrations; yet (2) the proportion of agricultural land has decreased and the proportion of urban land has increased since 1960. Urban land use is associated with low nitrate

  12. Transport of fecal-derived microorganisms from latrine ponds to aquifers in Bangladesh

    Science.gov (United States)

    Knappett, P. S.; McKay, L. D.; Layton, A.; Alam, M.; Williams, D.; Huq, M. R.; Mailloux, B. J.; Ferguson, A.; Feighery, J. E.; Culligan, P. J.; Escamilla, V.; Emch, M.; Akita, Y.; Serre, M. L.; Perfect, E.; Gentry, R. W.; Ahmed, K. M.; van Geen, A.

    2009-12-01

    Groundwater has been the principal source of drinking water for over 100 million people in rural Bangladesh for the past twenty years. The shallow depths and simple construction of the private wells has raised concern that these wells may be receiving fecal contamination from the densely populated rural areas with poor sanitation, contributing to high rates of diarrheal disease. Ponds are ubiquitous in Bangladesh, serving multiple purposes, including receiving fecal effluent from latrines, and private wells are frequently located in close proximity to these potential groundwater contamination sources. After detecting E. coli in up to 70% of private and monitoring wells throughout a village in Araihazar, the numerous ponds throughout the village were hypothesized to be sources of this contamination. To test this hypothesis 9 lateral transects of 4 monitoring wells each, 7 m deep and placed 1 m apart, were installed radiating away from four ponds of contrasting ages and near surface geology. These transects were monitored throughout the year to look for evidence that the ponds were contributing E. coli to the groundwater system. During the dry season from September 2008 to May 2009 no E. coli was observed in the shallow monitoring wells. In contrast, when the rains began in June 2009 several of the transects showed increasing water levels and E. coli with proximity to the pond, providing evidence that some ponds were acting as a contamination point source. A major rainfall event was simulated in June 2009 in each of the four ponds, raising the water level by 20 to 30 cm while adjacent transects were monitored. In two recently dug, deep ponds E. coli travelled up to 6 m into the medium sand aquifer within 24 hours as a result of the simulated rainfall event. In the two older ponds, which had well developed silt layers on the bottom or were emplaced in silty aquifers little E. coli was detected in the adjacent monitoring wells under natural or forced gradient

  13. Combining lead isotopes and cluster analysis to distinguish the Guarani and Serra Geral Aquifer Systems and contaminated waters in a highly industrialized area in Southern Brazil.

    Science.gov (United States)

    Kuhn, Isadora Aumond; Roisenberg, Ari

    2017-10-01

    The Rio dos Sinos Watershed area is located at the Middle-West region of the Rio Grande do Sul State, Southern Brazil, along thirty two municipalities and affecting 1.5 million inhabitants and many important industrial centers. Three main aquifers are recognized in the study area: the unconfined-fractured Serra Geral Aquifer System, the porous Guarani Aquifer System, and the Permian Aquitard. This study aims to understand groundwater, surface water and human activity interactions in the Rio dos Sinos Watershed, evaluating the application of stable lead isotopic ratios analyzed for this propose. Thirty six groundwater samples, 8 surface water samples and 5 liquid effluents of tanneries and landfills samples were measured using a Thermal Ionization Mass Spectrometer Thermo-Finnigan and a Neptune Multi-Collector Inductively Coupled Plasma Mass Spectrometer. Groundwater isotopic ratios have a wider range compared to the surface water, with less radiogenic averages (208)Pb/(204)Pb = 38.1837 vs 38.4050 (standard deviation = 0.2921 vs 0.1343) and (206)Pb/(204)Pb = 18.2947 vs 18.4766 (standard deviation = 0.2215 vs 0.1059), respectively. Industrial liquid effluents (tanneries and industrial landfill) have averages (208)Pb/(204)Pb = 38.1956 and (206)Pb/(204)Pb = 18.3169, distinct from effluent samples of domestic sanitary landfill (averages (208)Pb/(204)Pb = 38.2353 and (206)Pb/(204)Pb = 18.6607). Hierarchical cluster analysis led to distinguish six groups of groundwater, representing the three aquifers that occur in the area, two clusters suggesting groundwater mixtures and one demonstrating a highly contaminated groundwater. By analyzing the cluster results and wells' stratigraphic profiles it was possible to distinguish the different aquifers in the area. The Serra Geral Aquifer System has (206)Pb/(204)Pb ratios between 18.4718 and 18.7089; (207)Pb/(204)Pb between 15.6692 and 15.6777; (208)Pb/(204)Pb between 38.6826 and 38.7616; (207)Pb/(206)Pb between 0

  14. Can the Dupuit-Thiem equation accurately describe the flow pattern induced by injection in a laboratory scale aquifer-well system?

    Science.gov (United States)

    Bonilla, Jose; Kalwa, Fritz; Händel, Falk; Binder, Martin; Stefan, Catalin

    2016-04-01

    The Dupuit-Thiem equation is normally used to assess flow towards a pumping well in unconfined aquifers under steady-state conditions. For the formulation of the equation it is assumed that flow is laminar, radial and horizontal towards the well. It is well known that these assumptions are not met in the vicinity of the well; some authors restrict the application of the equation only to a radius larger than 1.5-fold the aquifer thickness. In this study, the equation accuracy to predict the pressure head is evaluated as a simple and quick analytical method to describe the flow pattern for different injection rates in the LSAW. A laboratory scale aquifer-well system (LSAW) was implemented to study the aquifer recharge through wells. The LSAW consists of a 1.0 m-diameter tank with a height of 1.1 meters, filled with sand and a screened well in the center with a diameter of 0.025 m. A regulated outflow system establishes a controlled water level at the tank wall to simulate various aquifer thicknesses. The pressure head at the bottom of the tank along one axis can be measured to assess the flow profile every 0.1 m between the well and the tank wall. In order to evaluate the accuracy of the Dupuit-Thiem equation, a combination of different injection rates and aquifer thicknesses were simulated in the LSAW. Contrary to what was expected (significant differences between the measured and calculated pressure heads in the well), the absolute difference between the calculated and measured pressure head is less than 10%. Beside this, the highest differences are not observed in the well itself, but in the near proximity of it, at a radius of 0.1 m. The results further show that the difference between the calculated and measured pressure heads tends to decrease with higher flow rates. Despite its limitations (assumption of laminar and horizontal flow throughout the whole aquifer), the Dupuit-Thiem equation is considered to accurately represent the flow system in the LSAW.

  15. The Role of Science in Managed Aquifer Recharge--the Equus Beds aquifer near Wichita, Kansas Andrew Ziegler, Director Brian Kelly, Office Chief Michael Jacobs, Manager of Water Planning and Production Debra Ary, Engineer, Water Systems Planning (Invited)

    Science.gov (United States)

    Ziegler, A. C.; Jacobs, M.; Ary, D.; Kelly, B.

    2013-12-01

    , and groundwater identified indicator bacteria, atrazine, chloride, sodium, nitrate, arsenic, iron, and manganese as constituents of concern exceeding water-quality criteria in baseline samples. Techniques were developed to estimate Little Arkansas River water quality in real-time for treatment. Geochemical modeling using PHREEQC and PHAST shows that groundwater quality is not changed if groundwater and recharge water are of similar redox potential. If different, calcite or metal hydroxides may precipitate and decrease water infiltration. A network of 38 locations with shallow and deep wells characterizes the recharge quantities and qualities for the city of Wichita to withdraw when needed from storage. Through 2013, the Demonstration project and Phase 1 and 2 facilities (capacity 40 MGD) have artificially recharged about 2 billion gallons. Total construction costs are about $300,000,000. Data-collection, interpretative geochemical and numerical simulations and water-quality transport modeling tools developed in the past 70 years are a scientific foundation to effectively and objectively manage this aquifer system.

  16. Evaluation and Preliminary Design of a Stormwater Aquifer Storage and Recovery (ASR) System at the Wadi Khulays Dunefield in Saudi Arabia

    KAUST Repository

    Lopez Valencia, Oliver M.

    2013-04-01

    An important source of freshwater in arid lands is found in groundwater aquifers that are recharged after storm events. However, most of the precipitation is lost due to evaporation and only small fractions actually recharge the aquifers. The construction of dams along wadi channels enables the retention of stormwater, however the reservoirs are still subject to huge evaporative losses and contamination. In this study, the hydraulic properties of a dunefield in western Saudi Arabia are evaluated in order to determine the feasibility of designing a stormwater storage aquifer storage and recovery facility using the dune sands as a natural medium and design recommendations are addressed. The accurate estimation of hydraulic conductivity of unlithified sediments such as dune sands has become very important in the design of natural filtration projects, including aquifer recharge and recovery systems. Therefore, a comparison and selection of methods for the determination of the hydraulic conductivity from grain size distribution found in the literature was done. An improvement to these equations based on measurements on dune samples was obtained.

  17. Integrating Spatial Multi Criteria Decision Making (SMCDM) with Geographic Information Systems (GIS) for delineation of the most suitable areas for aquifer storage and recovery (ASR)

    Science.gov (United States)

    Ahani Amineh, Zainab Banoo; Hashemian, Seyyed Jamal Al-Din; Magholi, Alireza

    2017-08-01

    Hamoon-Jazmoorian plain is located in southeast of Iran. Overexploitation of groundwater in this plain has led to water level decline and caused serious problems such as land subsidence, aquifer destruction and water quality degradation. The increasing population and agricultural development along with drought and climate change, have further increased the pressure on water resources in this region over the last years. In order to overcome such crisis, introduction of surface water into an aquifer at particular locations can be a suitable solution. A wide variety of methods have been developed to recharge groundwater, one of which is aquifer storage and recovery (ASR). One of the fundamental principles of making such systems is delineation of suitable areas based on scientific and natural facts in order to achieve relevant objectives. To that end, the Multi Criteria Decision Making (MCDM) in conjunction with the Geographic Information Systems (GIS) was applied in this study. More specifically, nine main parameters including depth of runoff as the considered source of water, morphology of the earth surface features such as geology, geomorphology, land use and land cover, drainage and aquifer characteristics along with quality of water in the aquifer were considered as the main layers in GIS. The runoff water available for artificial recharge in the basin was estimated through Soil Conservation Service (SCS) curve number method. The weighted curve number for each watershed was derived through spatial intersection of land use and hydrological soil group layers. Other thematic layers were extracted from satellite images, topographical map, and other collateral data sources, then weighed according to their influence in locating process. The Analytical Hierarchy Process (AHP) method was then used to calculate weights of individual parameters. The normalized weighted layers were then overlaid to build up the recharge potential map. The results revealed that 34% of the

  18. The use of salinity contrast for density difference compensation to improve the thermal recovery efficiency in high-temperature aquifer thermal energy storage systems

    Science.gov (United States)

    van Lopik, Jan H.; Hartog, Niels; Zaadnoordijk, Willem Jan

    2016-08-01

    The efficiency of heat recovery in high-temperature (>60 °C) aquifer thermal energy storage (HT-ATES) systems is limited due to the buoyancy of the injected hot water. This study investigates the potential to improve the efficiency through compensation of the density difference by increased salinity of the injected hot water for a single injection-recovery well scheme. The proposed method was tested through numerical modeling with SEAWATv4, considering seasonal HT-ATES with four consecutive injection-storage-recovery cycles. Recovery efficiencies for the consecutive cycles were investigated for six cases with three simulated scenarios: (a) regular HT-ATES, (b) HT-ATES with density difference compensation using saline water, and (c) theoretical regular HT-ATES without free thermal convection. For the reference case, in which 80 °C water was injected into a high-permeability aquifer, regular HT-ATES had an efficiency of 0.40 after four consecutive recovery cycles. The density difference compensation method resulted in an efficiency of 0.69, approximating the theoretical case (0.76). Sensitivity analysis showed that the net efficiency increase by using the density difference compensation method instead of regular HT-ATES is greater for higher aquifer hydraulic conductivity, larger temperature difference between injection water and ambient groundwater, smaller injection volume, and larger aquifer thickness. This means that density difference compensation allows the application of HT-ATES in thicker, more permeable aquifers and with larger temperatures than would be considered for regular HT-ATES systems.

  19. Chloride in Groundwater and Surface Water in Areas Underlain by the Glacial Aquifer System, Northern United States

    Science.gov (United States)

    Mullaney, John R.; Lorenz, David L.; Arntson, Alan D.

    2009-01-01

    A study of chloride in groundwater and surface water was conducted for the glacial aquifer system of the northern United States in forested, agricultural, and urban areas by analyzing data collected for the National Water-Quality Assessment Program from 1991 to 2004. Groundwater-quality data from a sampling of 1,329 wells in 19 states were analyzed. Chloride concentrations were greater than the secondary maximum contaminant level established by the U.S. Environmental Protection Agency of 250 milligrams per liter in 2.5 percent of samples from 797 shallow monitoring wells and in 1.7 percent of samples from 532 drinking-water supply wells. Water samples from shallow monitoring wells in urban areas had the largest concentration of chloride, followed by water samples from agricultural and forested areas (medians of 46, 12, and 2.9 milligrams per liter, respectively). An analysis of chloride:bromide ratios, by mass, and chloride concentrations compared to binary mixing curves for dilute groundwater, halite, sewage and animal waste, potassium chloride fertilizer, basin brines, seawater, and landfill leachate in samples from monitoring wells indicated multiple sources of chloride in samples from wells in urban areas and agricultural areas. Water from shallow monitoring wells in urban areas had the largest chloride:bromide ratio, and samples with chloride:bromide ratios greater than 1,000 and chloride concentrations greater than 100 milligrams per liter were dominated by halite; however, the samples commonly contained mixtures that indicated input from sewage or animal waste. Chloride:bromide ratios were significantly larger in samples from public-supply drinking-water wells than from private drinking-water wells, and ratios were significantly larger in all drinking-water wells in eastern and central regions of the glacial aquifer system than in west-central and western regions of the glacial aquifer system. Surface-water-quality data collected regularly during varying

  20. Aquifer Recharge and Watershed Response to Climate Change in the Upper Umatilla River Subbasin Using the Precipitation Runoff Modeling System

    Science.gov (United States)

    Yazzie, K.

    2014-12-01

    Groundwater recharge in the Columbia River Basalt Group (CRBG) in the Umatilla River Basin, OR, is poorly understood. The long-term decline of groundwater storage in the basalt aquifers, present a serious environmental challenge for the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). This study will provide a groundwater estimate to help CTUIR better understand the hydrologic budget and inform water management decisions for present and future needs. The study site is in the upper Umatilla River Subbasin in Northeastern Oregon with an area that is 2,365 km2. The Precipitation Runoff Modeling System (PRMS) developed by the U.S. Geological Survey (USGS) is a distributed-parameter, physical-process watershed model that will be used to calculate groundwater recharge and simulate the watershed response to different climate and land use scenarios (Markstrom, 2008). The response of the hydrologic regime to climate change in the 2050s and 2080s will be determined using three downscaled Global Climate Models (GCMs), including the Earth System model of the Hadley Centre Global Environment Model, Version 2 (HadGEM2-ES), Model for Interdisciplinary Research on Climate (MIROC5), and the Geophysical Fluid Dynamics Laboratory - Earth System Model, (GFDL-ESM2M). The relationships between hydrologic processes at the surface, soil-zone, subsurface and groundwater reservoirs will be studied and defined in a water budget analysis to characterize the hydrologic regime in response to climate change.

  1. Review: The Yucatán Peninsula karst aquifer, Mexico

    DEFF Research Database (Denmark)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2006-12-01

    Water chemistry in Boulder Creek, Colorado, shows significant variation as the Creek flows through the City of Boulder [Barber et al., 2006]. This variation is partially due to ground water inputs, which are not quantitatively understood. The purpose of this study is (1) to understand ground water movement in a shallow alluvial aquifer system and (2) to assess surface water/ground water interaction.