WorldWideScience

Sample records for groundwater contaminant migration

  1. Modeling the migration of radioactive contaminants in groundwater of in situ leaching uranium mine

    International Nuclear Information System (INIS)

    Li Chunguang; Tai Kaixuan

    2011-01-01

    The radioactive contamination of groundwater from in situ leaching (ISL) of uranium mining is a widespread environmental problem. This paper analyzed the monitor results of groundwater contaminations for a in situ leaching uranium mine. A dynamic model of contaminants transport in groundwater in ISL well field was established. The processes and mechanisms of contaminant transport in groundwater were simulated numerically for a ISL well field. A small quantity of U and SO 4 2- migrate to outside of well field during ISL production stage. But the migration velocity and distance of contaminations is small, and the concentration is low. Contaminants migrate as anomalistic tooth-shape. The migration trend of U and SO 4 2- is consistent. Numerical modeling can provide an effective approach to analyse the transport mechanism, and forecast and control the migration of contaminants in groundwater in ISL well field. (authors)

  2. Monitoring of Water and Contaminant Migration at the Groundwater-Surface Water Interface

    Science.gov (United States)

    2008-08-01

    seepage is occurring in a freshwater lake environment and to map the lateral extent of any subsurface contamination at the groundwater –surface water ...and Contaminant Migration at the Groundwater -Surface Water Interface August 2008 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...4. TITLE AND SUBTITLE Monitoring of Water and Contaminant Migration at the Groundwater -Surface Water Interface 5a. CONTRACT NUMBER 5b. GRANT NUMBER

  3. Software for modelling groundwater transport and contaminant migration

    International Nuclear Information System (INIS)

    Gishkelyuk, I.A.

    2008-01-01

    Facilities of modern software for modeling of groundwater transport and process of contaminant distribution are considered. Advantages of their application are discussed. The comparative analysis of mathematical modeling software of 'Groundwater modeling system' and 'Earth Science Module' from 'COMSOL Multiphysics' is carried out. (authors)

  4. Experimental and modelling studies of radionuclide migration from contaminated groundwaters

    International Nuclear Information System (INIS)

    Tompkins, J. A.; Butler, A. P.; Wheater, H. S.; Shaw, G.; Wadey, P.; Bell, J. N. B.

    1994-01-01

    Lysimeter-based studies of radionuclide uptake by winter wheat are being undertaken to investigate soil-to-plant transfer processes. A five year multi-disciplinary research project has concentrated on the upward migration of contaminants from near surface water-tables and their subsequent uptake by a winter wheat crop. A weighted transfer factor approach and a physically based modelling methodology, for the simulation and prediction of radionuclide uptake, have been developed which offer alternatives to the traditional transfer factor approach. Integrated hydrological and solute transport models are used to simulate contaminant movement and subsequent root uptake. This approach enables prediction of radionuclide transport for a wide range of soil, plant and radionuclide types. This paper presents simulated results of 22 Na plant uptake and soil activity profiles, which are verified with respect to lysimeter data. The results demonstrate that a simple modelling approach can describe the variability in radioactivity in both the harvested crop and the soil profile, without recourse to a large number of empirical parameters. The proposed modelling technique should be readily applicable to a range of scales and conditions, since it embodies an understanding of the underlying physical processes of the system. This work constitutes part of an ongoing research programme being undertaken by UK Nirex Ltd., to assess the long term safety of a deep level repository for low and intermediate level nuclear waste. (author)

  5. Modelling of contaminant migration in acidic groundwater plumes at uranium tailings impoundments: ADNEUT3

    International Nuclear Information System (INIS)

    Cherry, J.A.; Morin, K.A.; Dubrovsky, N.M.

    1984-06-01

    This report describes the creation and application of ADNEUT3, the latest addition to the ADNEUT (Acid-Drainage NEUTralization) family of computer programs for simulating acid-drainage transport and neutralization. The creation of ADNEUT3 involved the expansion of ADNEUT1 to allow variable input conditions such as changing input solution with time, variable initial amounts of minerals through the simulated streamtube, variable velocities through the streamtube, and variable solubilities for relevant minerals dependent on aqueous chemical composition. Concepts for simulating acid-drainage neutralization are reviewed and ADNEUT3 is then applied to a field-study site of acidic contaminant migration from the Nordic Main uranium-tailings impoundment near Elliot Lake, Ontario. A sensitivity study is first implemented to calibrate ADNEUT3 to the results of the 1979 to 1983 field studies. Then ADNEUT3 is used to define probable past conditions at the site which are not reliably known. In particular, ADNEUT3 is used to help identify: 1) the approximate year when acidic seepage began leaving the tailings impoundment (1966-1967), 2) the past chemical composition of the seepage (somewhat more acidic for a short period of time), and 3) the location of the source area within the tailings for the acidic seepage (near the impoundment dam, close to the field site). Finally, ADNEUT3 is used to predict future contaminant migration. Results indicate that hundreds of years are required under present conditions for the most acidic water with associated high levels of contaminants to migrate about 100 m from the tailings impoundment. The cause of this slow movement is the significant neutralization capacity of the aquifer. If acid production within the tailings decreases in the future, migration rates of contaminants will also decrease

  6. Groundwater contaminant plume ranking

    International Nuclear Information System (INIS)

    1988-08-01

    Containment plumes at Uranium Mill Tailings Remedial Action (UMTRA) Project sites were ranked to assist in Subpart B (i.e., restoration requirements of 40 CFR Part 192) compliance strategies for each site, to prioritize aquifer restoration, and to budget future requests and allocations. The rankings roughly estimate hazards to the environment and human health, and thus assist in determining for which sites cleanup, if appropriate, will provide the greatest benefits for funds available. The rankings are based on the scores that were obtained using the US Department of Energy's (DOE) Modified Hazard Ranking System (MHRS). The MHRS and HRS consider and score three hazard modes for a site: migration, fire and explosion, and direct contact. The migration hazard mode score reflects the potential for harm to humans or the environment from migration of a hazardous substance off a site by groundwater, surface water, and air; it is a composite of separate scores for each of these routes. For ranking the containment plumes at UMTRA Project sites, it was assumed that each site had been remediated in compliance with the EPA standards and that relict contaminant plumes were present. Therefore, only the groundwater route was scored, and the surface water and air routes were not considered. Section 2.0 of this document describes the assumptions and procedures used to score the groundwater route, and Section 3.0 provides the resulting scores for each site. 40 tabs

  7. In-situ study of migration and transformation of nitrogen in groundwater based on continuous observations at a contaminated desert site

    Science.gov (United States)

    Zuo, Rui; Jin, Shuhe; Chen, Minhua; Guan, Xin; Wang, Jinsheng; Zhai, Yuanzheng; Teng, Yanguo; Guo, Xueru

    2018-04-01

    The objective of this study was to explore the controlling factors on the migration and transformation of nitrogenous wastes in groundwater using long-term observations from a contaminated site on the southwestern edge of the Tengger Desert in northwestern China. Contamination was caused by wastewater discharge rich in ammonia. Two long-term groundwater monitoring wells (Wells 1# and 2#) were constructed, and 24 water samples were collected. Five key indicators were tested: ammonia, nitrate, nitrite, dissolved oxygen, and manganese. A numerical method was used to simulate the migration process and to determine the migration stage of the main pollutant plume in groundwater. The results showed that at Well 1# the nitrogenous waste migration process had essentially been completed, while at Well 2# ammonia levels were still rising and gradually transitioning to a stable stage. The differences for Well 1# and Well 2# were primarily caused by differences in groundwater flow. The change in ammonia concentration was mainly controlled by the migration of the pollution plume under nitrification in groundwater. The nitrification rate was likely affected by changes in dissolved oxygen and potentially manganese.

  8. Conceptual Models for Migration of Key Groundwater Contaminants Through the Vadose Zone and Into the Upper Unconfined Aquifer Below the B-Complex

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey; Bjornstad, Bruce N.; Keller, Jason M.; Thorne, Paul D.; Lanigan, David C.; Christensen, J. N.; Thomas, Gregory S.

    2010-07-01

    The B-Complex contains 3 major crib and trench disposal sites and 3 SST farms that have released nearly 346 mega-liters of waste liquids containing the following high groundwater risk drivers: ~14,000 kg of CN, 29,000 kg of Cr, 12,000 kg of U and 145 Ci of Tc-99. After a thorough review of available vadose zone sediment and pore water, groundwater plume, field gamma logging, field electrical resistivity studies, we developed conceptual models for which facilities have been the significant sources of the contaminants in the groundwater and estimated the masses of these contaminants remaining in the vadose zone and currently present in the groundwater in comparison to the totals released. This allowed us to make mass balance calculations on how consistent our knowledge is on the current deep vadose zone and groundwater distribution of contaminants. Strengths and weaknesses of the conceptual models are discussed as well as implications on future groundwater and deep vadose zone remediation alternatives. Our hypothesized conceptual models attribute the source of all of the cyanide and most of the Tc-99 currently in the groundwater to the BY cribs. The source of the uranium is the BX-102 tank overfill event and the source of most of the chromium is the B-7-A&B and B-8 cribs. Our mass balance estimates suggest that there are much larger masses of U, CN, and Tc remaining in the deep vadose zone within ~20 ft of the water table than is currently in the groundwater plumes below the B-Complex. This hypothesis needs to be carefully considered before future remediation efforts are chosen. The masses of these groundwater risk drivers in the the groundwater plumes have been increasing over the last decade and the groundwater plumes are migrating to the northwest towards the Gable Gap. The groundwater flow rate appears to flucuate in response to seasonal changes in hydraulic gradient. The flux of contaminants out of the deep vadose zone from the three proposed sources also

  9. A study on migration of contaminants and effect on the groundwater system at the Gemencheh domestic waste disposal site, Negeri Sembilan using integrated nuclear, geophysical and hydrogeochemical methods

    International Nuclear Information System (INIS)

    Mohd Tadza Abdul Rahman

    2001-01-01

    The domestic waste disposal site at Gemencheh, Negeri Sembilan has been in operation since 1981. Integration of three methods namely nuclear, geophysical and hydrogeochemical were used to study the migration and effects of contaminants on the groundwater system at this particular site. Nuclear method was used to determine groundwater system flow velocity that delineates the migration pattern of contaminant species in the groundwater system at the study area. The groundwater flow velocity is found to be heterogeneous and depend on hydraulic conductivity caused by soil permeability except in the low-lying downstream area where the flow velocity is found to be low and constant at 2.0 x 10 -6 ms -1 . However, the flow velocity increases to as high as 17.8 x 10 -5 ms -1 during rainy season due to the influence of weather on hydraulic gradient. Weather condition also influences the flow direction, whereby during draught season, the groundwater flow direction at the middle of the study site moves from an area of high topography to the northeast and southeast of low topography areas. On the other hand, at the downstream the groundwater flows partially towards northeast and southeast whereas flow direction at the upstream is towards the east. A similar pattern was observed during rainy season in both upstream and downstream of the study site but at the middle, the flow is basically towards south-east with a side flow to the north-east and east direction. Geophysical method comprising geo electrical-imaging and electromagnetic transient techniques was used to determine the extent, depth and distribution of contamination in the groundwater system. This method shows that the most seriously contaminated areas at the middle and the downstream regions of the study site within the shallow depth of 3-6 metres. The distribution of the contaminants in groundwater is not widespread but confined within the study site only. Finally, hydrogeochemical method was used to determine the

  10. Groundwater quality assessment for the Upper East Fork Poplar Creek Hydrogeologic Regime at the Y-12 Plant. 1991 groundwater quality data and calculated rate of contaminant migration

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    This report contains groundwater quality data obtained during the 1991 calendar year at several waste management facilities and petroleum fuel underground storage tank (UST) sites associated with the Y-12 Plant. These sites are within the Upper East Fork Poplar Creek Hydrogeologic Regime (UEFPCHR), which is one of three regimes defined for the purposes of groundwater and surface-water quality monitoring and remediation. This report was prepared for informational purposes. Included are the analytical data for groundwater samples collected from selected monitoring wells during 1991 and the results for quality assurance/quality control (QA/QC) samples associated with each groundwater sample. This report also contains summaries of selected data, including ion-charge balances for each groundwater sample, a summary of analytical results for nitrate (a principle contaminant in the UEFPCHR), results of volatile organic compounds (VOCs) analyses validated using the associated QA/QC sample data, a summary of trace metal concentrations which exceeded drinking-water standards, and a summary of radiochemical analyses and associated counting errors.

  11. Costs of groundwater contamination

    International Nuclear Information System (INIS)

    O'Neil, W.B.; Raucher, R.S.

    1990-01-01

    Two factors determine the cost of groundwater contamination: (1) the ways in which water was being used or was expected to be used in the future and (2) the physical characteristics of the setting that constrain the responses available to regain lost uses or to prevent related damages to human health and the environment. Most contamination incidents can be managed at a low enough cost that uses will not be foreclosed. It is important to take into account the following when considering costs: (1) natural cleansing through recharge and dilution can take many years; (2) it is difficult and costly to identify the exact area and expected path of a contamination plume; and (3) treatment or replacement of contaminated water often may represent the cost-effective strategy for managing the event. The costs of contamination include adverse health effects, containment and remediation, treatment and replacement costs. In comparing the costs and benefits of prevention programs with those of remediation, replacement or treatment, it is essential to adjust the cost/benefit numbers by the probability of their actual occurrence. Better forecasts of water demand are needed to predict more accurately the scarcity of new supply and the associated cost of replacement. This research should include estimates of the price elasticity of water demand and the possible effect on demand of more rational cost-based pricing structures. Research and development of techniques for in situ remediation should be encouraged

  12. Sources of groundwater contamination

    International Nuclear Information System (INIS)

    Assaf, H.; Al-Masri, M. S.

    2007-09-01

    In spite of the importance of water for life, either for drinking, irrigation, industry or other wide uses in many fields, human beings seem to contaminate it and make it unsuitable for human uses. This is due to disposal of wastes in the environment without treatment. In addition to population increase and building expanding higher living costs, industrial and economical in growth that causes an increase in water consumption. All of these factors have made an increase pressure on our water environment quantitatively and qualitatively. In addition, there is an increase of potential risks to the water environmental due to disposal of domestic and industrial wastewater in areas near the water sources. Moreover, the use of unacceptable irrigation systems may increase soil salinity and evaporation rates. The present report discusses the some groundwater sources and problem, hot and mineral waters that become very important in our life and to our health due to its chemical and radioactivity characteristics.(authors)

  13. Chemical barriers for controlling groundwater contamination

    International Nuclear Information System (INIS)

    Morrison, S.J.; Spangler, R.R.

    1993-01-01

    Chemical barriers are being explored as a low-cost means of controlling groundwater contamination. The barrier can intercept a contaminant plume and prevent migration by transferring contaminants from the groundwater to immobile solids. A chemical barrier can be emplaced in a landfill liner or in an aquifer cutoff wall or can be injected into a contaminant plume. Chemical barriers can be classified as either precipitation barriers or sorption barriers depending upon the dominant mode of contaminant extraction. In a precipitation barrier, contaminants are bound in the structures of newly formed phases; whereas, in a sorption barrier, contaminants attach to the surfaces of preexisting solids by adsorption or some other surface mechanism. Sorption of contaminants is pH dependent. A precipitation barrier can control the pH of the system, but alkaline groundwater may dominate the pH in a sorption barrier. A comparison is made of the characteristics of precipitation and sorption barriers. Experimental data on the extraction of uranium and molybdenum from simulated groundwater are used to demonstrate these concepts. 10 refs., 9 figs., 1 tab

  14. Isotope hydrology: Investigating groundwater contamination

    International Nuclear Information System (INIS)

    Dubinchuk, V.; Froehlich, K.; Gonfiantini, R.

    1989-01-01

    Groundwater quality has worsened in many regions, with sometimes serious consequences. Decontaminating groundwater is an extremely slow process, and sometimes impossible, because of the generally long residence time of the water in most geological formations. Major causes of contamination are poor groundwater management (often dictated by immediate social needs) and the lack of regulations and control over the use and disposal of contaminants. These types of problems have prompted an increasing demand for investigations directed at gaining insight into the behaviour of contaminants in the hydrological cycle. Major objectives are to prevent pollution and degradation of groundwater resources, or, if contamination already has occurred, to identify its origin so that remedies can be proposed. Environmental isotopes have proved to be a powerful tool for groundwater pollution studies. The IAEA has had a co-ordinated research programme since 1987 on the application of nuclear techniques to determine the transport of contaminants in groundwater. An isotope hydrology project is being launched within the framework of the IAEA's regional co-operative programme in Latin America (known as ARCAL). Main objectives are the application of environmental isotopes to problems of groundwater assessment and contamination in Latin America. In 1989, another co-ordinated research programme is planned under which isotopic and other tracers will be used for the validation of mathematical models in groundwater transport studies

  15. Migration of a groundwater contaminant plume by stratabound flow in Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Ketelle, R.H.; Lee, R.R.

    1992-08-01

    The discovery of radiologically contaminated groundwater in core hole CH-8 in the western portion of Waste Area Grouping (WAG) 1 at Oak Ridge National Laboratory (ORNL) prompted a detailed investigation to identify the contaminant plume. Utilizing a working hypothesis of stratabound groundwater flow and contaminant transport, investigators analyzed existing subsurface geologic data to predict the contaminant plume discharge location in first Creek and locations of contaminated groundwater seepage into storm drains. The hypothesis states that differential lithologic/fracture conditions lead to the development of preferred flow and transport pathways, of discrete vertical extent, which may not be coincident with the hydraulic gradient. Leakage out of the stratabound pathway is a minor component of the overall plume configuration

  16. Water use and groundwater contamination

    International Nuclear Information System (INIS)

    Elton, J.J.; Livingstone, B.

    1998-01-01

    A general review of the groundwater resources in Saskatchewan and their vulnerability to contamination was provided. In particular, the use of water and the effects on water by the oil and gas industry in Saskatchewan were discussed. It was suggested that public concerns over scarcity and contamination of water are gradually changing perceptions about Canada's abundance of water. Saskatchewan's surface water covers 12 per cent of the province. About 90 per cent of the rural populations and 80 per cent of municipalities depend on groundwater supplies. Regulations affecting oil and gas operations that could affect water resources have become more stringent. Techniques used in the detection and monitoring of groundwater affected by salt and petroleum hydrocarbons were described. Electromagnetic surveys are used in detecting salt-affected soils and groundwater. Laboratory analysis of chloride concentrations are needed to define actual chloride concentrations in groundwater. Wells and barriers can be installed to control and recover chloride plumes. Deep well injection and reverse osmosis are other methods, but there is no cheap or simple treatment or disposal method for salt-impacted groundwater. Spills or leaks of petroleum hydrocarbons from various sources can also lead to contamination of groundwater. Various assessment and remediation methods are described. Although there is no scarcity of techniques, all of them are difficult, costly, and may take several years to complete. 11 refs., 1 tab

  17. Groundwater recharge and agricultural contamination

    Science.gov (United States)

    Böhlke, J.K.

    2002-01-01

    Agriculture has had direct and indirect effects on the rates and compositions of groundwater recharge and aquifer biogeochemistry. Direct effects include dissolution and transport of excess quantities of fertilizers and associated materials and hydrologic alterations related to irrigation and drainage. Some indirect effects include changes in water–rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agricultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO3–, N2, Cl, SO42–, H+, P, C, K, Mg, Ca, Sr, Ba, Ra, and As, as well as a wide variety of pesticides and other organic compounds. For reactive contaminants like NO3–, a combination of chemical, isotopic, and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. Groundwater records derived from multi-component hydrostratigraphic data can be used to quantify recharge rates and residence times of water and dissolved contaminants, document past variations in recharging contaminant loads, and identify natural contaminant-remediation processes. These data indicate that many of the world's surficial aquifers contain transient records of changing agricultural contamination from the last half of the 20th century. The transient agricultural groundwater signal has important implications for long-term trends and spatial heterogeneity in discharge.

  18. Groundwater quality assessment for the Bear Creek Hydrogeologic Regime at the Y-12 Plant: 1991 groundwater quality data and calculated rate of contaminant migration

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    The report contains groundwater and surface water quality data obtained during the 1991 calendar year at several hazardous and non- hazardous waste management facilities associated with the US Department of Energy (DOE) Y-12 Plant (Figure 1). These sites are southwest of the Y-12 Plant complex within the Bear Creek Hydrogeologic Regime (BCHR), which is one of three regimes defined for the purposes of groundwater and surface-water quality monitoring and remediation (Figure 2). The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability (HSEA) Division manages the monitoring activities in each regime as part of the Y-12 Plant Groundwater Protection Program (GWPP).

  19. Groundwater quality assessment for the Bear Creek Hydrogeologic Regime at the Y-12 Plant: 1991 groundwater quality data and calculated rate of contaminant migration

    International Nuclear Information System (INIS)

    1992-02-01

    The report contains groundwater and surface water quality data obtained during the 1991 calendar year at several hazardous and non- hazardous waste management facilities associated with the US Department of Energy (DOE) Y-12 Plant (Figure 1). These sites are southwest of the Y-12 Plant complex within the Bear Creek Hydrogeologic Regime (BCHR), which is one of three regimes defined for the purposes of groundwater and surface-water quality monitoring and remediation (Figure 2). The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability (HSEA) Division manages the monitoring activities in each regime as part of the Y-12 Plant Groundwater Protection Program (GWPP)

  20. Assessment of emerging groundwater contaminants

    OpenAIRE

    Stuart, Marianne; Lapworth, Dan; Manamsa, Katya; Crane, Emily; White, Debbie

    2016-01-01

    Emerging contaminants in groundwater are important. These have been studied at a range of scales. An increasing range of compounds is being detected Urban areas show impact of sewage and industrial wastewater. Some ECs are probably no threat to drinking water at such µg/L concentrations, e.g. caffeine Others may prove to be in the future. There is little information on their impact on other groundwater receptors in the environment. We are still far from understanding which of these comp...

  1. Effects of sorption behaviour on contaminant migration

    International Nuclear Information System (INIS)

    Melnyk, T.W.

    1985-11-01

    The effects of sorption behaviour on contaminant migration in groundwater systems are varied. Retardation of migration and dispersive effects can vary widely and contaminant concentration profiles can take a number of different shapes. This report examines the nature of some of these effects, especially those due to sorption behaviours that are dependent on the concentration of the contaminant in the groundwater. The effects are calculated using, in most cases, analytical solutions to the chemical equations imbedded in a simple reaction-cell or box-model transport algorithm. The hydrogeological parameters are held constant, and radioactive decay and hydrodynamic dispersion are excluded. A general discussion of the role of sorption equations in transport modelling is followed by presentation of migration results for a number of models of sorption behaviour varying from linear isotherms, Langmuir, Freundlich and ion-exchange isotherms, to precipitation reactions and multiple-site sorption reactions. The results are compared and general conclusions are drawn about the various migration behaviours calculated. The conclusions are that equilibrium sorption of trace contaminants can be modelled with linear isotherms (constant distribution coefficients or constant retardation factors) but the evaluation and extrapolation of the distribution coefficient are not easy. Nonlinear isotherms lead to unsymmetrical migration fronts. A comparison of Freundlich and linear isotherms is made. Sorption/desorption kinetic factors can be significant on the time scale of laboratory experiments and can cause large dispersive effects. Slow but important reactions can be missed altogether. Precipitation or mineralization behaviour cannot be modelled with constant distribution coefficients. Also, mineralization reactions can be kinetically slow even on the geological time scale. 89 refs

  2. Groundwater arsenic contamination throughout China.

    Science.gov (United States)

    Rodríguez-Lado, Luis; Sun, Guifan; Berg, Michael; Zhang, Qiang; Xue, Hanbin; Zheng, Quanmei; Johnson, C Annette

    2013-08-23

    Arsenic-contaminated groundwater used for drinking in China is a health threat that was first recognized in the 1960s. However, because of the sheer size of the country, millions of groundwater wells remain to be tested in order to determine the magnitude of the problem. We developed a statistical risk model that classifies safe and unsafe areas with respect to geogenic arsenic contamination in China, using the threshold of 10 micrograms per liter, the World Health Organization guideline and current Chinese standard for drinking water. We estimate that 19.6 million people are at risk of being affected by the consumption of arsenic-contaminated groundwater. Although the results must be confirmed with additional field measurements, our risk model identifies numerous arsenic-affected areas and highlights the potential magnitude of this health threat in China.

  3. Geoelectrical mapping and groundwater contamination

    Science.gov (United States)

    Blum, Rainer

    Specific electrical resistivity of near-surface materials is mainly controlled by the groundwater content and thus reacts extremely sensitive to any change in the ion content. Geoelectric mapping is a well-established, simple, and inexpensive technique for observing areal distributions of apparent specific electrical resistivities. These are a composite result of the true resistivities in the underground, and with some additional information the mapping of apparent resistivities can help to delineate low-resistivity groundwater contaminations, typically observed downstream from sanitary landfills and other waste sites. The presence of other good conductors close to the surface, mainly clays, is a serious noise source and has to be sorted out by supporting observations of conductivities in wells and geoelectric depth soundings. The method may be used to monitor the extent of groundwater contamination at a specific time as well as the change of a contamination plume with time, by carrying out repeated measurements. Examples for both are presented.

  4. Emerging contaminants in groundwater

    OpenAIRE

    Lapworth, Dan; Stuart, Marianne; Hart, Alwyn; Crane, Emily; Baran, Nicole

    2011-01-01

    The term ‘emerging contaminants’ (ECs) is used to cover not only newly developed compounds but also includes newly discovered compounds in the environment (often due to analytical developments), and compounds that have been recently categorised as contaminants. ECs include a huge array of different compounds (and their metabolites) that are used by society for a range of purposes and include; pharmaceuticals, pesticides, personal care products, veterinary medicines, engineered nano-materials,...

  5. Cone penetrometer testing (CPT) for groundwater contamination

    International Nuclear Information System (INIS)

    Jordan, J.E.; Van Pelt, R.S.

    1993-01-01

    Over the past decade, researchers at the Savannah River Site (SRS) and elsewhere have greatly advanced the knowledge of waste site characterization technologies. As a result, many of the techniques used in the past to investigate waste sites have been replaced by newer technologies, designed to provide greater protection for human health and the environment, greater access to suspected zones of contamination, and more accurate information of subsurface conditions. Determining the most environmentally sound method of assessing a waste unit is a major component of the SRS environmental restoration program. In an effort to understand the distribution and migration of contaminants in the groundwater system, the cone penetrometer investigation of the A/M-Area Southern Sector was implemented. The program incorporated a phased approach toward characterization by first using the CPT to delineate the plume boundary, followed by installing groundwater monitoring wells. The study provided the additional hydrogeologic information necessary to better understand the nature and extent of the contaminant plume (Fig. 1) and the hydrogeologic system in the Southem Sector. This data is essential for the optimal layout of the planned groundwater monitoring well network and recovery system to remediate the aquifers in the area. A number of other test locations were selected in the area during this study for lithologic calibration of the tool and to collect confirmation water samples from the aquifer. Cone penetrometer testing and hydrocone sampling, were performed at 17 sites (Fig. 2). The hydrocone, a tool modification to the CPT, was used to collect four groundwater samples from confined aquifers. These samples were analyzed by SRS laboratories. Elevated levels of chlorinated compounds were detected from these samples and have aided in further delineating the southern sector contaminant plume

  6. Emerging organic contaminants in groundwater

    OpenAIRE

    Stuart, Marianne; Lapworth, Dan

    2013-01-01

    Emerging organic contaminants (ECs) are compounds now being found in groundwater from agricultural, urban sources that were previously not detectable, or thought to be significant. ECs include pesticides and degradates, pharmaceuticals, industrial compounds, personal care products, fragrances, water treatment by-products, flame retardants and surfactants, as well as ‘life-style’ compounds such as caffeine and nicotine. ECs may have adverse effects on aquatic ecosystems and human health. Freq...

  7. Chemical speciation of radionuclides migrating in groundwaters

    International Nuclear Information System (INIS)

    Robertson, D.; Schilk, A.; Abel, K.; Lepel, E.; Thomas, C.; Pratt, S.; Cooper, E.; Hartwig, P.; Killey, R.

    1994-04-01

    In order to more accurately predict the rates and mechanisms of radionuclide migration from low-level waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particular, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species that appear to be predominantly organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g., 60 Co and 106 Ru, into a number of specific compounds or groups of compounds. Further identification of the anionic organoradionuclide complexes is planned utilizing high resolution mass spectrometry. Large-volume ultra-filtration experiments are characterizing the particulate forms of radionuclides being transported in these groundwaters

  8. Spatial control of groundwater contamination, using principal

    Indian Academy of Sciences (India)

    Spatial control of groundwater contamination, using principal component analysis ... anthropogenic (agricultural activities and domestic wastewaters), and marine ... The PC scores reflect the change of groundwater quality of geogenic origin ...

  9. Groundwater fluoride contamination: A reappraisal

    Directory of Open Access Journals (Sweden)

    Amlan Banerjee

    2015-03-01

    Full Text Available Dissolution of fluorite (CaF2 and/or fluorapatite (FAP [Ca5(PO43F], pulled by calcite precipitation, is thought to be the dominant mechanism responsible for groundwater fluoride (F− contamination. Here, one dimensional reactive–transport models are developed to test this mechanism using the published dissolution and precipitation rate kinetics for the mineral pair FAP and calcite. Simulation results correctly show positive correlation between the aqueous concentrations of F− and CO32− and negative correlation between F− and Ca2+. Results also show that precipitation of calcite, contrary to the present understanding, slows down the FAP dissolution by 106 orders of magnitude compared to the FAP dissolution by hydrolysis. For appreciable amount of fluoride contamination rock–water interaction time must be long and of order 106 years.

  10. ARSENIC CONTAMINATION IN GROUNDWATER: A STATISTICAL MODELING

    Directory of Open Access Journals (Sweden)

    Palas Roy

    2013-01-01

    Full Text Available High arsenic in natural groundwater in most of the tubewells of the Purbasthali- Block II area of Burdwan district (W.B, India has recently been focused as a serious environmental concern. This paper is intending to illustrate the statistical modeling of the arsenic contaminated groundwater to identify the interrelation of that arsenic contain with other participating groundwater parameters so that the arsenic contamination level can easily be predicted by analyzing only such parameters. Multivariate data analysis was done with the collected groundwater samples from the 132 tubewells of this contaminated region shows that three variable parameters are significantly related with the arsenic. Based on these relationships, a multiple linear regression model has been developed that estimated the arsenic contamination by measuring such three predictor parameters of the groundwater variables in the contaminated aquifer. This model could also be a suggestive tool while designing the arsenic removal scheme for any affected groundwater.

  11. Simulation–optimization model for groundwater contamination ...

    Indian Academy of Sciences (India)

    used techniques for groundwater remediation in which the contaminated groundwater is pumped ... ing the affected groundwater aquifer down to some drinking water standard. Several .... For simplicity, rectangular support domain is used in this study. Figure 1 ..... For PAT remediation system, decision variables include the.

  12. ARSENIC CONTAMINATION IN GROUNDWATER: A STATISTICAL MODELING

    OpenAIRE

    Palas Roy; Naba Kumar Mondal; Biswajit Das; Kousik Das

    2013-01-01

    High arsenic in natural groundwater in most of the tubewells of the Purbasthali- Block II area of Burdwan district (W.B, India) has recently been focused as a serious environmental concern. This paper is intending to illustrate the statistical modeling of the arsenic contaminated groundwater to identify the interrelation of that arsenic contain with other participating groundwater parameters so that the arsenic contamination level can easily be predicted by analyzing only such parameters. Mul...

  13. Numerical prediction of 239Pu migration for groundwater pollution in the infiltration case

    International Nuclear Information System (INIS)

    Liu Dongxu; Si Gaohua; Wang Qinghai; Yu Jing

    2010-01-01

    In terms of the study on site selection of geological disposal of LIL radioactive waste in north-west China, a numerical prediction of 239 Pu migration for potential groundwater pollution in the unsaturated zone was conducted with the HYDRUS-ID model. The results showed that the groundwater will not be contaminated by the migration of soluble 239 Pu. And there is a faint possibility that 239 Pu migration through groundwater path might have an unacceptable impact on ecosphere. Measurements of the distribution coefficient, K d , are critical in the determination of sorption-induced retardation of radionuclide transport. (authors)

  14. Water and contaminant movement: migration barriers

    International Nuclear Information System (INIS)

    Lane, L.J.; Nyhan, J.W.

    1984-11-01

    Migration barriers are used in shallow land burial facilities to slow or stop the movement of water and contaminants and are discussed here as a single component embedded in a complex environmental system. Analytical solutions to solute transport equations are used to approximate the behavior of migration barriers and to derive design criteria for control of subsurface water and contaminant migration. Various types of migration barriers are compared and design recommendations are made for shallow land burial trench caps and liners. Needed improvements and suggested field experiments for future designs of migration barriers are then discussed relative to the management of low-level radioactive wastes

  15. Mechanisms of contaminant migration from grouted waste

    International Nuclear Information System (INIS)

    Magnuson, S.O.; Yu, A.D.

    1992-01-01

    Low-level radioactive decontaminated salt solution is generated at the Savannah River Site (SRS) from the In-Tank Precipitation process. The solution is mixed with cement, slag, and fly ash, to form a grout, termed ''Saltstone'', that will be disposed in concrete vaults at the Saltstone Disposal Facility (SDF) [1]. Of the contaminants in the Saltstone, the greatest concern to SRS is the potential release of nitrate to the groundwater because of the high initial nitrate concentration (0.25 g/cm 3 ) in the Saltstone and the low Safe Drinking Water Act (SDWA) maximum contaminant level (MCL) of 44 mg/L. The SDF is designed to allow a slow, controlled release over thousands of years. This paper addresses a modeling study of nitrate migration from intact non-degraded concrete vaults in the unsaturated zone for the Radiological Performance Assessment (PA) of the SRS Saltstone Disposal Facility [3]. The PA addresses the performance requirements mandated by DOE Order 5820.2A [4

  16. Spatial control of groundwater contamination, using principal ...

    Indian Academy of Sciences (India)

    probe into the spatial controlling processes of groundwater contamination, using principal component analysis (PCA). ... topography, soil type, depth of water levels, and water usage. Thus, the ... of effective sites for infiltration of recharge water.

  17. Groundwater migration of radionuclides at Fermilab

    International Nuclear Information System (INIS)

    Malensek, A.J.; Wehmann, A.A.; Elwyn, A.J.; Moss, K.J.; Kesich, P.M.

    1993-01-01

    The simple Single Resident Well (SRW) Model has been used to calculate groundwater movement since Fermilab's inception. A new Concentration Model is proposed which is more realistic and takes advantage of computer modeling that has been developed for the siting of landfills. Site geologic and hydrologic data were given to a consultant who made the migration calculations from an initial concentration that was based upon the existing knowledge of the radioactivity leached out of the soil. The various components of the new Model are discussed, and numerical examples are given and compared with DOE/EPA limits

  18. Evaluation of contaminated groundwater cleanup objectives

    International Nuclear Information System (INIS)

    Arquiett, C.; Gerke, M.; Datskou, I.

    1996-01-01

    The US Department of Energy's (DOE's) Environmental Restoration Program will be responsible for remediating the approximately 230 contaminated groundwater sites across the DOE Complex. A major concern for remediation is choosing the appropriate cleanup objective. The cleanup objective chosen will influence the risk to the nearby public during and after remediation; risk to remedial and non-involved workers during remediation; and the cost of remediation. This paper discusses the trends shown in analyses currently being performed at Oak Ridge National Laboratories' (ORNL's) Center for Risk Management (CRM). To evaluate these trends, CRM is developing a database of contaminated sites. This paper examines several contaminated groundwater sites selected for assessment from CRM's data base. The sites in this sample represent potential types of contaminated groundwater sites commonly found at an installation within DOE. The baseline risk from these sites to various receptors is presented. Residual risk and risk during remediation is reported for different cleanup objectives. The cost associated with remediating to each of these objectives is also estimated for each of the representative sites. Finally, the general trends of impacts as a function of cleanup objective will be summarized. The sites examined include the Savannah River site, where there was substantial ground pollution from radionuclides, oil, coal stockpiles, and other forms of groundwater contamination. The effects of various types of groundwater contamination on various types of future user is described. 4 refs., 3 figs., 2 tabs

  19. Transport of contaminated groundwater to a river

    International Nuclear Information System (INIS)

    Zeevaert, T.

    1990-09-01

    Scenario B7 deals with the discharges of Cs-137, Sr-90, Pu-239 and Np-237 with the groundwater from an aquifer into a river, through the river sediment. The contamination of agricultural soil, brought about through the dredging of top sediment from the river, was also considered. Four models participated in this exercise, providing best estimate values. Only one model supplied uncertainty estimates. Brief descriptions of the models and their aims are given. the modelling of the processes taken into account for the computation of the radionuclide concentrations in river and soil compartments are described and the input parameter values are given. The model results are discussed and the reasons for the differences between the models are explained. Important discrepancies were observed. As far as the steady-state concentrations are concerned they were due to differences in the parameter values and transfer processes considered. The time-dependent concentration values depended strongly on the approach adopted for the modelling of the migration of the nuclides through the deep sediment in the source region. The major source of uncertainty pointed out by the model which performed an uncertainty analysis, was the distribution coefficient in the deep sediment. The conclusions and recommendations for improvement of the models, given at the end of the report, accentuate the lack of understanding of the phenomena occurring at the geosphere-biosphere interface and the importance of good communications between scientists of different disciplines. (au)

  20. Migration behavior of landfill leachate contaminants through alternative composite liners

    Energy Technology Data Exchange (ETDEWEB)

    Varank, Gamze, E-mail: gvarank@yildiz.edu.tr; Demir, Ahmet, E-mail: ahmetd@yildiz.edu.tr; Top, Selin, E-mail: stop@yildiz.edu.tr; Sekman, Elif, E-mail: esekman@yildiz.edu.tr; Akkaya, Ebru, E-mail: ekoca@yildiz.edu.tr; Yetilmezsoy, Kaan, E-mail: yetilmez@yildiz.edu.tr; Bilgili, M. Sinan, E-mail: mbilgili@yildiz.edu.tr

    2011-08-01

    Four identical pilot-scale landfill reactors with different alternative composite liners were simultaneously operated for a period of about 540 days to investigate and to simulate the migration behaviors of phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and heavy metals (Pb, Cu, Zn, Cr, Cd, Ni) from landfill leachate to the groundwater. Alternative landfill liners of four reactors consist of R1: Compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R2: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R3: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + bentonite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn), and R4: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + zeolite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn). Wastes representing Istanbul municipal solid wastes were disposed in the reactors. To represent bioreactor landfills, reactors were operated by leachate recirculation. To monitor and control anaerobic degradation in the reactors, variations of conventional parameters (pH, alkalinity, chloride, conductivity, COD, TOC, TKN, ammonia and alcaly metals) were also investigated in landfill leachate samples. The results of this study showed that about 35-50% of migration of organic contaminants (phenolic compounds) and 55-100% of migration of inorganic contaminants (heavy metals) to the model groundwater could be effectively reduced with the use of bentonite and zeolite materials in landfill liner systems. Although leachate contaminants can reach to the groundwater in trace concentrations, findings of this study concluded that the release of these compounds from landfill leachate to the groundwater may potentially be of an important environmental concern based on the experimental findings. - Research highlights: {yields} Migration of

  1. Association of leukemia with radium groundwater contamination

    International Nuclear Information System (INIS)

    Lyman, G.H.; Lyman, C.G.; Johnson, W.

    1985-01-01

    Radiation exposure, including the ingestion of radium, has been causally associated with leukemia in man. Groundwater samples from 27 counties on or near Florida phosphate lands were found to exceed 5 pCi/L total radium in 12.4% of measurements. The incidence of leukemia was greater in those counties with high levels of radium contamination (greater than 10% of the samples contaminated) than in those with low levels of contamination. Rank correlation coefficients of .56 and .45 were observed between the radium contamination level and the incidence of total leukemia and acute myeloid leukemia, respectively. The standardized incidence density ratio for those in high-contamination counties was 1.5 for total leukemia and 2.0 for acute myeloid leukemia. Further investigation is necessary, however, before a causal relationship between groundwater radium content and human leukemia can be established

  2. In situ remediation of uranium contaminated groundwater

    International Nuclear Information System (INIS)

    Dwyer, B.P.; Marozas, D.C.

    1997-01-01

    In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ to acceptable regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of tailing pile effluent. Experimental design, and laboratory and field results are discussed with regard to other potential contaminated groundwater treatment applications

  3. Blast fracturing of bedrock to enhance recovery of contaminated groundwater

    International Nuclear Information System (INIS)

    Holzman, L.R.; Harvey, E.M.; McKee, R.C.E.; Katsabanis, T.

    1992-01-01

    Petroleum hydrocarbons releasd from a pipeline at a site in southern Ontario had contaminated a fractured dolostone bedrock aquifer. To remediate the site, contaminated groundwater was pumped from the downgradient edge of the hydrocarbon plume and injected into an upgradient area after treatment. Contaminant flow pathways in the fractured bedrock aquifer were found to be complex and erratic. It was anticipated that contaminated groundwater could escape the influence of a line of closely spaced recovery wells. In order to capture the migrating contaminants effectively, improve communication between recovery wells, and optimize pumping efficiencies, a rubble zone was created by drilling and blasting the rock. Using 140 blastholes, the bedrock was fractured to a depth of 4 m over a distance of 200 m. Similarly, an additional 80 blastholes were used to blast fracture 100 m of bedrock to a depth of 4 m in the recharge area to enhance injection of treated water to the aquifer. Various blasthole spacings and explosive loadings and patterns were tested to fracture the rock effectively while minimizing the impact on the nearby pipeline and neighboring residences. Vibrations were carefully monitored using several seismographs. Pump tests conducted before and after the blast indicated the hydraulic connection between the naturally occurring fractures had greatly improved. Monitoring conducted after startup of the pump-treat-and-inject system has confirmed the fracturing provides effective capture and injection of the groundwater. 3 refs., 3 figs., 1 tab

  4. Modeling dissolution and volatilization of LNAPL sources migrating on the groundwater table.

    Science.gov (United States)

    Kim, Jeongkon; Corapcioglu, M Yavuz

    2003-08-01

    A vertically averaged two-dimensional model was developed to describe areal spreading and migration of light nonaqueous-phase liquids (LNAPLs) introduced into the subsurface by spills or leaks from underground storage tanks. The NAPL transport model was coupled with two-dimensional contaminant transport models to predict contamination of soil gas and groundwater resulting from a LNAPL migrating on the water table. Numerical solutions were obtained by using the finite-difference method. Simulations and sensitivity analyses were conducted with a LNAPL of pure benzene to study LNAPL migration and groundwater contamination. The model was applied to subsurface contamination by jet fuel. Results indicated that LNAPL migration were affected mostly by volatilization. The generation and movement of the dissolved plume was affected by the geology of the site and the free-product plume. Most of the spilled mass remained as a free LNAPL phase 20 years after the spill. The migration of LNAPL for such a long period resulted in the contamination of both groundwater and a large volume of soil.

  5. Groundwater contamination and community relations

    International Nuclear Information System (INIS)

    Hayes, K.

    2004-01-01

    Westinghouse Electric Company LLC ('Westinghouse') acquired a nuclear fuel processing plant at Hematite, Missouri ('Hematite', the 'Facility', or the 'Plant') in April 2000. The plant has subsequently been closed, and its operations have been relocated to a newer, larger facility. Westinghouse has announced plans to complete its clean-up, decommissioning, and License retirement in a safe, socially responsible, and environmentally sound manner as required by internal policies, as well as those of its parent company, British Nuclear Fuels plc. (BNFL). Preliminary investigations have revealed the presence of environmental contamination in various areas of the facility and grounds, including both radioactive contamination and various other substances related to the nuclear fuel processing operations. Most noteworthy among the areas of contamination are seven private drinking water wells up to 3 000 feet to the southeast, and one private drinking water well approximately 1 000 feet to the northeast, that have been found to contain tetra-chloro-ethylene ('PCE'), trichloroethylene ('TCE'), and other contaminants associated with their environmental degradation. Potential sources of this contamination include approximately 40 large unlined on-site burial pits and 2 evaporation ponds in which previous operators of the facility disposed of uranium contaminated wastes and a variety of other hazardous substances. This paper discusses Westinghouse's response to the discovery of drinking water contamination, and the significance of its community relations program within that response. (author)

  6. Leukemia and radium groundwater contamination

    International Nuclear Information System (INIS)

    Tracy, B.L.; Letourneau, E.G.

    1986-01-01

    In the August 2, 1985, issue of JAMMA, Lyman et al claim to have shown an association between leukemia incidence in Florida and radium in groundwater supplies. Although cautious in their conclusions, the authors imply that this excess in leukemia was in fact caused by radiation. The authors believe they have not presented a convincing argument for causation. The radiation doses at these levels of exposure could account for only a tiny fraction of the leukemia excess

  7. A review of groundwater contamination near municipal solid waste landfill sites in China.

    Science.gov (United States)

    Han, Zhiyong; Ma, Haining; Shi, Guozhong; He, Li; Wei, Luoyu; Shi, Qingqing

    2016-11-01

    Landfills are the most widely used method for municipal solid waste (MSW) disposal method in China. However, these facilities have caused serious groundwater contamination due to the leakage of leachate. This study, analyzed 32 scientific papers, a field survey and an environmental assessment report related to groundwater contamination caused by landfills in China. The groundwater quality in the vicinity of landfills was assessed as "very bad" by a comprehensive score (FI) of 7.85 by the Grading Method in China. Variety of pollutants consisting of 96 groundwater pollutants, 3 organic matter indicators, 2 visual pollutants and 6 aggregative pollutants had been detected in the various studies. Twenty-two kinds of pollutants were considered to be dominant. According to the Kruskal-Wallis test and the median test, groundwater contamination differed significantly between regions in China, but there were no significant differences between dry season and wet season measurements, except for some pollutants in a few landfill sites. Generally, the groundwater contamination appeared in the initial landfill stage after five years and peaked some years afterward. In this stage, the Nemerow Index (PI) of groundwater increased exponentially as landfill age increased at some sites, but afterwards decreased exponentially with increasing age at others. After 25years, the groundwater contamination was very low at selected landfills. The PI values of landfills decreased exponentially as the pollutant migration distance increased. Therefore, the groundwater contamination mainly appeared within 1000m of a landfill and most of serious groundwater contamination occurred within 200m. The results not only indicate that the groundwater contamination near MSW landfills should be a concern, but also are valuable to remediate the groundwater contamination near MSW landfills and to prevent the MSW landfill from secondary pollutions, especially for developing countries considering the similar

  8. Calendar year 1993 groundwater quality report for the Chestnut Ridge Hydrogeologic Regime, Y-12 Plant, Oak Ridge, Tennessee. 1993 groundwater quality data and calculated rate of contaminant migration, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    This annual groundwater report contains groundwater quality data obtained during the 1993 calendar year (CY) at several hazardous and non-hazardous waste-management facilities associated with the US Department of Energy (DOE) Y-12 Plant located on the DOE Oak Ridge Reservation (ORR) southeast of Oak Ridge, Tennessee. These sites are located south of the Y-12 Plant in the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime), which is one of three regimes defined for the purposes of groundwater quality monitoring at the Y-12 Plant. The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability Organization manages the groundwater monitoring activities in each regime as part of the Y-12 Plant Groundwater Protection Program (GWPP). The annual groundwater report for the Chestnut Ridge Regime is completed in two-parts; Part 1 (this report) containing the groundwater quality data and Part 2 containing a detailed evaluation of the data. The primary purpose of this report is to serve as a reference for the groundwater quality data obtained each year under the lead of the Y-12 Plant GWPP. However, because it contains information needed to comply with Resource Conservation and Recovery Act (RCRA) interim status assessment monitoring and reporting requirements, this report is submitted to the Tennessee Department of Health and Environment (TDEC) by the RCRA reporting deadline.

  9. Calendar year 1995 groundwater quality report for the Chestnut Ridge Hydrogeological Regime, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. 1995 Groundwater quality data and calculated rate of contaminant migration

    International Nuclear Information System (INIS)

    1996-02-01

    This annual groundwater quality report (GWQR) contains groundwater quality data obtained during the 1995 calendar year (CY) at several hazardous and nonhazardous waste management facilities associated with the U.S. Department of Energy (DOE) Y-12 Plant located on the DOE Oak Ridge Reservation (ORR) southeast of Oak Ridge, Tennessee. These sites are located south of the Y-12 Plant in the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime), which is one of three regimes defined for the purposes of groundwater quality monitoring at the Y-12 Plant. The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability (HSEA) Organization manages the groundwater monitoring activities in each regime as part of the Y-12 Plant Groundwater Protection Program (GWPP). The U.S. Environmental Protection Agency (EPA) identification number for the Y-12 Plant is TN

  10. Nitrate contamination of groundwater and its countermeasures

    Energy Technology Data Exchange (ETDEWEB)

    Mitamura, Hisayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The inevitable increases of food production and energy consumption with an increase in world population become main causes of an increase of nitrate load to the environment. Although nitrogen is essential for the growth of animal and plant as a constituent element of protein, excessive nitrate load to the environment contaminates groundwater resources used as drinking water and leads to seriously adverse effects on the health of man and livestock. In order to clarify the problem of nitrate contamination of groundwater and search a new trend of technology development from the viewpoint of environment remediation and protection, the present paper has reviewed adverse effects of nitrate on human health, the actual state of nitrogen cycle, several kinds of nitrate sources, measures for reducing nitrate level, etc. (author)

  11. Characterisation of contamination migration in the workplace

    International Nuclear Information System (INIS)

    Boulaud, D.; Laborde, J.C.; Pourprix, M.

    1994-01-01

    The Institute for Nuclear Safety and Protection (IPSN) has developed a procedure for characterising airborne contamination between processes and the workplace in nuclear facilities. It was initially intended to use this process to validate operator choices concerning the monitoring of indoor air contamination (personnel monitoring, and environmental detection at fixed locations), but also to optimise the fundamental parameters which have a more or less direct influence on potential exposure of staff in the workplace (at the same time optimising the contamination source, close confinement, process ventilation and general ventilation). In practice, the methods used to obtain these expert appraisals were usually based on experiments carried out in situ: (i) characterisation of aerosol contamination by accurate measurement of the nature, concentration and particle size distribution at various locations; (ii) characterisation of the migration of contamination by precise measurement involving gas and/or particle tracing techniques. In parallel with these experiments, a considerable effort was made to develop and qualify computer codes capable of predicting or estimating the migration of contamination through complex ventilated areas, by means of both fluid mechanics and aerosol science. (Author)

  12. Geostatistical analysis of prevailing groundwater conditions and potential solute migration at Elstow, Bedfordshire

    International Nuclear Information System (INIS)

    MacKay, R.; Cooper, T.A.; Porter, J.D.; O'Connell, P.E.; Metcalfe, A.V.

    1988-06-01

    A geostatistical approach is applied in a study of the potential migration of contaminants from a hypothetical waste disposal facility near Elstow, Bedfordshire. A deterministic numerical model of groundwater flow in the Kellaways Sands formation and adjacent layers is coupled with geostatistical simulation of the heterogeneous transmissivity field of this principal formation. A particle tracking technique is used to predict the migration pathways for alternative realisations of flow. Alternative statistical descriptions of the spatial structure of the transmissivity field are implemented and the temporal and spatial distributions of escape of contaminants to the biosphere are investigated. (author)

  13. Calendar year 1995 groundwater quality report for the upper east Fork Poplar Creek Hydrogeologic regime, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. 1995 Groundwater quality data and calculated rate of contaminant migration

    International Nuclear Information System (INIS)

    1996-02-01

    This annual groundwater quality report (GWQR) contains groundwater and surface water quality data obtained during the 1995 calendar year (CY) at several waste management facilities associated with the U.S. Department of Energy (DOE) Y-12 Plant located on the DOE Oak Ridge Reservation (ORR) southeast of Oak Ridge, Tennessee. The U.S. Environmental Protection Agency (EPA) identification number for the Y-12 Plant is TN3 89 009 0001. The sites addressed by this document are located within the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime). The East Fork Regime, which is one of three hydrogeologic regimes defined for the purposes of groundwater quality monitoring at the Y-12 Plant, encompasses the Y-12 Plant

  14. Ground-water contamination and legal controls in Michigan

    Science.gov (United States)

    Deutsch, Morris

    1963-01-01

    The great importance of the fresh ground-water resources of Michigan is evident because 90 percent of the rural and about 70 percent of the total population of the State exclusive of the Detroit metropolitan area are supplied from underground sources. The water-supply and public-health problems that have been caused by some cases of ground-water contamination in the State illustrate the necessity of protecting this vital resource.Manmade and natural contaminants, including many types of chemical and organic matter, have entered many of the numerous aquifers of the State. Aquifers have been contaminated by waste-laden liquids percolating from the surface or from the zone of aeration and by direct injection to the aquifer itself. Industrial and domestic wastes, septic tanks, leaking sewers, flood waters or other poor quality surface waters, mine waters, solids stored or spread at the surface, and even airborne wastes all have been sources of ground-water contamination in Michigan. In addition, naturally occurring saline waters have been induced into other aquifers by overpumping or unrestricted flow from artesian wells, possibly by dewatering operations, and by the deepening of surface stream channels. Vertical migration of saline waters through open holes from formations underlying various important aquifers also has spoiled some of the fresh ground waters in the State. In spite of the contamination that has occurred, however, the total amount of ground water that has been spoiled is only a small part of the total resource. Neither is the contamination so widespread as that of the surface streams of Michigan.Overall legal authority to control most types of ground-water contamination in the State has been assigned by the Michigan Legislature to the Water Resources Commission, although the Department of Conservation and the Health Department also exercise important water-pollution control functions. The Michigan Supreme Court, in an important case upholding the power

  15. Radionuclide migration in groundwater. Annual progress report for 1982

    International Nuclear Information System (INIS)

    Robertson, D.E.; Toste, A.P.; Abel, K.H.; Brodzinski, R.L.

    1984-01-01

    Research has continued at a low-level waste disposal facility to characterize the physicochemical species of radionuclides migrating in groundwater. This facility consists of an unlined basin and connecting trench which receives effluent water containing low levels of a wide variety of fission and activation products and trace amounts of transuranic radionuclides. The effluent water percolates through the soil and a small fraction of it emerges at seepage springs located some 260 meters from the trench. The disposal basin and trench are very efficient in retaining most of the radionuclides, but trace amounts of a number of radionuclides existing in mobile chemical forms migrate in the groundwater from the trench to the springs. This facility provides the opportunity for characterizing the rates and mechanisms of radionuclide migration in groundwaters, identifying retardation processes, and validating geochemical models. 13 references, 25 figures, 23 tables

  16. Nanoparticles migration in fractured rocks and affects on contaminant migration

    Science.gov (United States)

    Missana, Tiziana; Garcia-Gutierrez, Miguel; Alonso, Ursula

    2014-05-01

    In previous studies, the transport behavior of artificial (gold and latex) and natural (smectite clay) colloids, within a planar fracture in crystalline rock, was analyzed. In order to better understand the effects of colloid size, shape and surface charge on nanoparticle migration and especially on filtration processes on natural rock surfaces, different clay colloids and oxide nanoparticles were selected and their transport studied as a function of the residence time. In all the cases, (a fraction of) the nanoparticles travelled in the fracture as fast as or faster than water (with a retardation factor, Rf ≤ 1) and the observed Rf, was related to the Taylor dispersion coefficient, accounting for colloid size, water velocity and fracture width. However, under most of the cases, in contrast to the behavior of a conservative tracer, colloids recovery was much lower than 100 %. Differences in recovery between different nanoparticles, under similar residence times, were analyzed. In order to evaluate the possible consequences, on contaminant migration, of the presence of nanoparticles in the system, transport tests were carried out with both colloids and sorbing radionuclides. The overall capacity for colloids of enhancing radionuclide migration in crystalline rock fractures is discussed. Acknowledgments: The research leading to these results received funding from EU FP7/2007-2011 grant agreement Nº 295487 (BELBAR, Bentonite Erosion: effects on the Long term performance of the engineered Barrier and Radionuclide Transport) and by the Spanish Government under the project NANOBAG (CTM2011-2797).

  17. Groundwater flow and tritium migration from the SRS Old Burial Ground to Fourmile Branch

    International Nuclear Information System (INIS)

    Flach, G.P.; Hamm, L.L.; Harris, M.K.

    1996-04-01

    The objectives of this investigation are twofold. The initial goal is to devise and demonstrate a technique for directly incorporating fine-scale lithologic data into heterogeneous hydraulic conductivity fields, for improved groundwater flow and contaminant transport model accuracy. The ultimate goal is to rigorously simulate past and future tritium migration from the SRS Old Burial Ground towards Fourmile Branch, to better understand the effects of various remediation alternatives such as no action and capping. Large-scale variability in hydraulic conductivity is usually the main influence on field-scale groundwater flow patterns and dispersive transport, following the relative locations of recharge and discharge areas. Incorporating realistic hydraulic conductivity heterogeneity into flow and transport models is paramount to accurate simulations, particularly for contaminant migration. Sediment lithologic descriptions and geophysical logs typically offer finer spatial resolution, and therefore more potential information about heterogeneity, than other site characterization data

  18. Arsenic migration to deep groundwater in Bangladesh influenced by adsorption and water demand

    Science.gov (United States)

    Radloff, K. A.; Zheng, Y.; Michael, H. A.; Stute, M.; Bostick, B. C.; Mihajlov, I.; Bounds, M.; Huq, M. R.; Choudhury, I.; Rahman, M. W.; Schlosser, P.; Ahmed, K. M.; van Geen, A.

    2011-11-01

    The consumption of shallow groundwater with elevated concentrations of arsenic is causing widespread disease in many parts of South and Southeast Asia. In the Bengal Basin, a growing reliance on groundwater sourced below 150-m depth--where arsenic concentrations tend to be lower--has reduced exposure. Groundwater flow simulations have suggested that these deep waters are at risk of contamination due to replenishment with high-arsenic groundwater from above, even when deep water pumping is restricted to domestic use. However, these simulations have neglected the influence of sediment adsorption on arsenic migration. Here, we inject arsenic-bearing groundwater into a deep aquifer zone in Bangladesh, and monitor the reduction in arsenic levels over time following stepwise withdrawal of the water. Arsenic concentrations in the injected water declined by 70% after 24h in the deep aquifer zone, owing to adsorption on sediments; concentrations of a co-injected inert tracer remain unchanged. We incorporate the experimentally determined adsorption properties of sands in the deep aquifer zone into a groundwater flow and transport model covering the Bengal Basin. Simulations using present and future scenarios of water-use suggest that arsenic adsorption significantly retards transport, thereby extending the area over which deep groundwater can be used with low risk of arsenic contamination. Risks are considerably lower when deep water is pumped for domestic use alone. Some areas remain vulnerable to arsenic intrusion, however, and we suggest that these be prioritized for monitoring.

  19. Understanding arsenic contamination of groundwater in Bangladesh

    International Nuclear Information System (INIS)

    Kabir, Babar

    2001-01-01

    The problem of water contamination by naturally occurring arsenic confronts governments, public and private utilities, and the development community with a new challenge for implementing operational mitigation activities under difficult conditions of imperfect knowledge - especially for arsenic mitigation for the benefit of the rural poor. With more than a conservative estimate of 20 million of its 130 million people assumed to be drinking contaminated water and another 70 million potentially at risk, Bangladesh is facing what has been described as perhaps the largest mass poisoning in history. High concentrations of naturally occurring arsenic have already been found in water from tens of thousands of tube wells, the main source of potable water, in 59 out of Bangladesh's 64 districts. Arsenic contamination is highly irregular, so tube wells in neighboring locations or even different depths can be safe. Arsenic is extremely hazardous if ingested in drinking water or used in cooking in excess of the maximum permissible limit of 0.01 mg/liter over an extended period of time. Even in the early 1970s, most of Bangladesh's rural population got its drinking water from surface ponds and nearly a quarter of a million children died each year from water-borne diseases. Groundwater now constitutes the major source of drinking water in Bangladesh with 95% of the drinking water coming from underground sources. The provision of tube well water for 97 percent of the rural population has been credited with bringing down the high incidence of diarrheal diseases and contributing to a halving of the infant mortality rate. Paradoxically, the same wells that saved so many lives now pose a threat due to the unforeseen hazard of arsenic. The provenance of arsenic rich minerals in sediments of the Bengal basin as a component of geological formations is believed to be from the Himalayan mountain range. Arsenic has been found in different uncropped geological hard rock formations

  20. Influence of basalt/groundwater interactions on radionuclide migration

    International Nuclear Information System (INIS)

    Vandegrift, G.F.

    1984-01-01

    The work presented here is a partial summary of the experimental results obtained in the Laboratory Analog Program. Two aspects of this effort are (1) the interaction between simulated basaltic groundwater and basalt fissures that were either freshly cleaved or laboratory altered by hydrothermal treatment with the simulated groundwater and (2) the effect of this interaction on radionuclide migration through these basalt fissures. The following conclusions of this study bear heavily on the predicted safety of a basalt repository: Sorption properties of freshly fissured basalt and naturally aged basalt are quite different for different chemical species. Analog experiments predict that aged basalt would be an effective retarder of cesium, but would be much less so for actinide elements. Distribution ratios measured from batch experiments with finely ground rock samples (presenting unaltered rock surfaces) are not a reliable means of predicting radionuclide migration in geological repositories. As the near-repository area is resaturated by groundwater, its ability to retard actinide migration will be degraded with time. Disturbing the natural flow of groundwater through the repository area by constructing and backfilling the repository will modify the composition of groundwater. This modified groundwater is likely to interact with and to modify naturally aged basalt surfaces downstream from the repository

  1. Remediating Contaminant Plumes in Groundwater with Shallow Excavations Containing Coarse Reactive Media.

    Science.gov (United States)

    Hudak, Paul F

    2018-02-01

    A groundwater flow and mass transport model tested the capability of shallow excavations filled with coarse, reactive media to remediate a hypothetical unconfined aquifer with a maximum saturated thickness of 5 m. Modeled as contaminant sinks, the rectangular excavations were 10 m downgradient of an initial contaminant plume originating from a source at the top of the aquifer. The initial plume was approximately 259 m long, 23 m wide, and 5 m thick, with a downgradient tip located approximately 100 m upgradient of the site boundary. The smallest trench capable of preventing offsite migration was 11 m long (measured perpendicular to groundwater flow), 4 m wide (measured parallel to groundwater flow), and 3 m deep. Results of this study suggest that shallow trenches filled with coarse filter media that partially penetrate unconfined aquifers may be a viable alternative for remediating contaminated groundwater at some sites.

  2. Potassium ferrate treatment of RFETS' contaminated groundwater

    International Nuclear Information System (INIS)

    1995-01-01

    The potassium ferrate treatment study of Rocky Flats Environmental Technology Site (RFETS) groundwater was performed under the Sitewide Treatability Studies Program (STSP). This study was undertaken to determine the effectiveness of potassium ferrate in a water treatment system to remove the contaminants of concern (COCS) from groundwater at the RFETS. Potassium ferrate is a simple salt where the iron is in the plus six valence state. It is the iron at the plus six valence state (Fe +6 ) that makes it an unique water treatment chemical, especially in waters where the pH is greater than seven. In basic solutions where the solubility of the oxides/hydroxides of many of the COCs is low, solids are formed as the pH is raised. By using ferrate these solids are agglomerated so they can be effectively removed by sedimentation in conventional water treatment equipment. The objective of this study was to determine the quality of water after treatment with potassium ferrate and to determine if the Colorado Water Quality Control Commission (CWQCC) discharge limits for the COCs listed in Table 1.0-1 could be met. Radionuclides in the groundwater were of special concern

  3. Emerging contaminants in urban groundwater sources in Africa.

    Science.gov (United States)

    Sorensen, J P R; Lapworth, D J; Nkhuwa, D C W; Stuart, M E; Gooddy, D C; Bell, R A; Chirwa, M; Kabika, J; Liemisa, M; Chibesa, M; Pedley, S

    2015-04-01

    The occurrence of emerging organic contaminants within the aquatic environment in Africa is currently unknown. This study provides early insights by characterising a broad range of emerging organic contaminants (n > 1000) in groundwater sources in Kabwe, Zambia. Groundwater samples were obtained during both the dry and wet seasons from a selection of deep boreholes and shallow wells completed within the bedrock and overlying superficial aquifers, respectively. Groundwater sources were distributed across the city to encompass peri-urban, lower cost housing, higher cost housing, and industrial land uses. The insect repellent DEET was ubiquitous within groundwater at concentrations up to 1.8 μg/L. Other compounds (n = 26) were detected in less than 15% of the sources and included the bactericide triclosan (up to 0.03 μg/L), chlorination by-products - trihalomethanes (up to 50 μg/L), and the surfactant 2,4,7,9-tetramethyl-5-decyne-4,7-diol (up to 0.6 μg/L). Emerging contaminants were most prevalent in shallow wells sited in low cost housing areas. This is attributed to localised vulnerability associated with inadequate well protection, sanitation, and household waste disposal. The five-fold increase in median DEET concentration following the onset of the seasonal rains highlights that more mobile compounds can rapidly migrate from the surface to the aquifer suggesting the aquifer is more vulnerable than previously considered. Furthermore it suggests DEET is potentially useful as a wastewater tracer in Africa. There was a general absence of personal care products, life-style compounds, and pharmaceuticals which are commonly detected in the aquatic environment in the developed world. This perhaps reflects some degree of attenuation within the subsurface, but could also be a result of the current limited use of products containing emerging contaminants by locals due to unaffordability and unavailability. As development and population increases in Africa, it is

  4. The peculiarity of the models of the contamination's migration in water in the Chernobyl region

    International Nuclear Information System (INIS)

    Kononovich, A.L.; Krishev, I.I.; Oskolkov, B.Ja.; Kulebakina, L.G.; Arhipov, N.P.

    1997-01-01

    The new factors become significant for Chernobyl's contamination's evolution after 8-10 years. Those factors were hidden in the early 3-5 years. Our paper describes the mathematical model of the migration's process of the radionuclides in Chernobyl cooling pond and some results about the migration of the 137 Cs by groundwater. Our model for radionuclide's migration in the Chernobyl cooling pond differ from other mathematical models, that it takes into account the destruction of the fuel's particles during the time. It shows increased concentration of the 90 Sr in water and the monotonous decrease 137 Cs concentration in water. The results of the model's calculation of the annual concentration of the 137 Cs and 90 Sr in water coincide with measurements results in less than 20%. It is the only model of the Chernobyl cooling pond, which has so good coincidence during 10 years. Result of this work shows that the main process, which determines the time's dependence of the annual concentration of the radionuclides in Chernobyl cooling pond, is the destruction of the fuel's particles. In the second part of the paper there is result of the investigation 137 Cs migration by groundwater. The investigation was made with combination of the physical's modelling and mathematical's modelling methods. Truer is discussion about similarity of the physical-chemical simulation and real process. We had investigated the real Chernobyl's ground's contamination in the physical-chemical's similar model's system. It has observed the fraction of the 137 Cs in groundwater's contamination with very low sorption's coefficient, and thus the big migration's velocity (like 90 Sr). The part of the speed component is about 10 -4 . But the components of 137 Cs contamination, which has the big sorption's coefficient, converts slowly into the 'speed form' during the time. We had no see any publication about 'speed component' of 137 Cs contamination in Chernobyl's groundwater. All contemporary models of

  5. A technical approach to groundwater contamination problems

    International Nuclear Information System (INIS)

    Burton, J.C.; Leser, C.; Rose, C.M.

    1993-01-01

    Argonne National Laboratory has been performing technical investigations at sites in Nebraska and Kansas that have identified groundwater contamination by carbon tetrachloride. This comprehensive program will ultimately provide the affected communities with safe drinking water. The first step in the program is to evaluate the available data and identify sites that will require an Alternate Water Supply Study (AWSS). The objective of the AWSS is to identify options for providing a safe drinking water supply to all users, in compliance with the Safe Drinking Water Act. The AWSS consists of an engineering and cost evaluation followed by implementation of the selected alternative. For sites with contamination less than a specific concentration, the AWSS is regarded as a satisfactory long term solution, and no further action is taken. For those sites with concentrations above that specific limit, the AWSS implementation is regarded as only a stopgap measure, and the site is selected for additional remedial action. The first step of the remedial action is an Expedited Site Characterization (ESC). The ESC was developed at Argonne to decrease the cost and time of the remedial investigation and feasibility study while producing a high-quality technical investigation. The ESC is designed to characterize the contaminant plume configuration and movement, which requires an understanding of the geological and hydrogeologic controls on groundwater movement as well as the nature and extent of any remaining carbon tetrachloride source in the soils. The ESC program uses a multidisciplinary technical approach that incorporates geology, geochemistry, geohydrology, and geophysics. Field activities include sampling, chemical analysis, and borehole and surface geophysical surveys

  6. Technical options for the remediation of contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    1999-06-01

    This report provides a description of the nature and extent of problems related to radioactive groundwater contamination by outlining the environmental impacts, the sources of contamination and the contaminants of concern radionuclides and their associated contaminants - the main exposure pathways and transport processes and the assessment of risks associated with contaminated groundwater. The main emphasis of this report is on methodologies used in groundwater remediation and available technologies. The methodology section outlines the importance of an initial scoping analysis including the evaluation of uncertainties of the available data and the necessity for defining clear objectives for data collection. This is then followed by comprehensive site characterization, setting of goals and developing alternatives which will be analysed in detail. Available technologies are grouped generally into in situ methods aiming at a containment of the contaminants in place and engineered treatment methods involving an alteration of groundwater flow, quantity and/or quality to achieve compliance with set goals. Groundwater remediation by natural flushing allows the natural groundwater movement and geochemical processes to decrease the contaminant concentrations to acceptable levels over a specified period of time. This method is increasingly accepted in areas where the use of groundwater can be temporarily restricted or engineered cleanup methods do not offer particular advantage over the natural processes. The application of technological methods for remediating contaminated groundwaters has to be considered in conjunction with management options such as diversion and development of alternative water sources. The experience with groundwater contamination accrued in IAEA Member States is concentrated in those countries with active uranium mining and milling facilities and nuclear energy programmes. This experience is reported in the Annexes, which include case studies. It

  7. Technical options for the remediation of contaminated groundwater

    International Nuclear Information System (INIS)

    1999-06-01

    This report provides a description of the nature and extent of problems related to radioactive groundwater contamination by outlining the environmental impacts, the sources of contamination and the contaminants of concern radionuclides and their associated contaminants - the main exposure pathways and transport processes and the assessment of risks associated with contaminated groundwater. The main emphasis of this report is on methodologies used in groundwater remediation and available technologies. The methodology section outlines the importance of an initial scoping analysis including the evaluation of uncertainties of the available data and the necessity for defining clear objectives for data collection. This is then followed by comprehensive site characterization, setting of goals and developing alternatives which will be analysed in detail. Available technologies are grouped generally into in situ methods aiming at a containment of the contaminants in place and engineered treatment methods involving an alteration of groundwater flow, quantity and/or quality to achieve compliance with set goals. Groundwater remediation by natural flushing allows the natural groundwater movement and geochemical processes to decrease the contaminant concentrations to acceptable levels over a specified period of time. This method is increasingly accepted in areas where the use of groundwater can be temporarily restricted or engineered cleanup methods do not offer particular advantage over the natural processes. The application of technological methods for remediating contaminated groundwaters has to be considered in conjunction with management options such as diversion and development of alternative water sources. The experience with groundwater contamination accrued in IAEA Member States is concentrated in those countries with active uranium mining and milling facilities and nuclear energy programmes. This experience is reported in the Annexes, which include case studies. It

  8. Characteristics and factors of groundwater contamination in Asian coastal megacities

    Science.gov (United States)

    Saito, M.; Onodera, S. I.; Jin, G.; Shimizu, Y.; Admajaya, F. T.

    2017-12-01

    For the sustainable use of groundwater resources for the future, it is important to conserve its quality as well as quantity. Especially in the developing megacities, land subsidence and groundwater pollution by several contaminants (e.g. nitrogen, trace metals and organic pollutants etc.) is one of a critical environmental problems, because of the intensive extraction of groundwater and huge amount of contaminant load derived from domestic wastewater as well as agricultural and industrial wastewater. However, the process of groundwater degradation, including depletion and contamination with urbanization, has not been examined well in the previous studies. In the present study, we aim to confirm the characteristics and factors of groundwater contamination in coastal Asian megacities such as Osaka and Jakarta. In Osaka, groundwater was used as a water resource during the period of rapid population increase before 1970, and consequently groundwater resources have been degraded. Hydraulic potential of groundwater has been recovered after the regulation for abstraction. However, it is still below sea level in the deeper aquifer (>20 m) of some regions, and higher Cl-, NH4+-N and PO43-P concentrations were detected in these regions. The results also suggest that shallower aquifer (>10 m) is influenced by infiltration of sewage to groundwater. In the Jakarta metropolitan area, current hydraulic potential is below sea level in because of prior excess abstraction of groundwater. As a result, the direction of groundwater flow is now downward in the coastal area. The distribution of Cl- and Mn concentration in groundwater suggests that the decline in hydraulic potential has caused the intrusion of seawater and shallow groundwater into deep groundwater. It implies an accumulation of contaminants in deep aquifers. On the other hands, NO3-N in groundwater is suggested to be attenuated by the processes of denitrification and dilution in the coastal area.

  9. Contaminated groundwater characterization at the Chalk River Laboratories, Ontario, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Schilk, A.J.; Robertson, D.E.; Thomas, C.W.; Lepel, E.A. [Pacific Northwest National Lab., Richland, WA (United States); Champ, D.R.; Killey, R.W.D.; Young, J.L.; Cooper, E.L. [Chalk River Labs., Chalk River, Ontario (Canada)

    1993-03-01

    The licensing requirements for the disposal of low-level radioactive waste (10 CFR 61) specify the performance objectives and technical requisites for federal and commercial land disposal facilities, the ultimate goal of which is to contain the buried wastes so that the general population is adequately protected from harmful exposure to any released radioactive materials. A major concern in the operation of existing and projected waste disposal sites is subterranean radionuclide transport by saturated or unsaturated flow, which could lead to the contamination of groundwater systems as well as uptake by the surrounding biosphere, thereby directly exposing the general public to such materials. Radionuclide transport in groundwater has been observed at numerous commercial and federal waste disposal sites [including several locations within the waste management area of Chalk River Laboratories (CRL)], yet the physico-chemical processes that lead to such migration are still not completely understood. In an attempt to assist in the characterization of these processes, an intensive study was initiated at CRL to identify and quantify the mobile radionuclide species originating from three separate disposal sites: (a) the Chemical Pit, which has received aqueous wastes containing various radioisotopes, acids, alkalis, complexing agents and salts since 1956, (b) the Reactor Pit, which has received low-level aqueous wastes from a reactor rod storage bay since 1956, and (c) the Waste Management Area C, a thirty-year-old series of trenches that contains contaminated solid wastes from CRL and various regional medical facilities. Water samples were drawn downgradient from each of the above sites and passed through a series of filters and ion-exchange resins to retain any particulate and dissolved or colloidal radionuclide species, which were subsequently identified and quantified via radiochemical separations and gamma spectroscopy. These groundwaters were also analyzed for anions

  10. Cyclic metal migration in a groundwater stream

    International Nuclear Information System (INIS)

    Goerlich, W.; Portmann, W.; Wernli, C.; Linder, P.; Burkart, W.

    1988-04-01

    The behaviour of dissolved (<0.45 μm) inorganic species (e.g. metals, anions), and changes in relevant properties of polluted river water during infiltration into adjacent groundwater are investigated. Water from the river and from several wells is analyzed for temporal and spacial changes. For many of the measured quantities a pronounced annual cycle is observed. The temperature differences between summer and winter influence biological activity. Growth and degradation of organic material lead to drastic changes in pH and redox conditions in the near infiltration field. During summer, under relatively anoxic conditions, manganese oxides/hydroxides dissolve. In winter, the higher concentration of dissolved oxygen induce reprecipitation of manganese. Trace metal mobility (e.g. Cu, Zn, Cd) is influenced by these annual variations. In the river, daily cycles are observed for many of the measured quantities. These short term variations are induced by photosynthesis and respiration of aquatic biota. The cyclic behaviour disappears during the early stage of infiltration. The changes between river and groundwater can be modelled by a combination of simplified electron transfer and weathering reactions. (author) 11 refs., 5 figs

  11. In Situ Monitoring of Groundwater Contamination Using the Kalman Filter For Sustainable Remediation

    Science.gov (United States)

    Schmidt, F.; Wainwright, H. M.; Faybishenko, B.; Denham, M. E.; Eddy-Dilek, C. A.

    2017-12-01

    Sustainable remediation - based on less intensive passive remediation and natural attenuation - has become a desirable remediation alternative at contaminated sites. Although it has a number of benefits, such as reduced waste and water/energy usage, it carries a significant burden of proof to verify plume stability and to ensure insignificant increase of risk to public health. Modeling of contaminant transport is still challenging despite recent advances in numerical methods. Long-term monitoring has, therefore, become a critical component in sustainable remediation. However, the current approach, which relies on sparse groundwater sampling, is problematic, since it could miss sudden significant changes in plume behavior. A new method is needed to combine existing knowledge about contaminant behavior and latest advances in in situ groundwater sensors. This study presents an example of the effective use of the Kalman filter approach to estimate contaminant concentrations, based on in situ measured water quality parameters (e.g. electrical conductivity and pH) along with the results of sparse groundwater sampling. The Kalman filter can effectively couple physical models and data correlations between the contaminant concentrations and in situ measured variables. We aim (1) to develop a framework capable of integrating different data types to provide accurate contaminant concentration estimates, (2) to demonstrate that these results remain reliable, even when the groundwater sampling frequency is reduced, and (3) to evaluate the future efficacy of this strategy using reactive transport simulations. This framework can also serve as an early warning system for detecting unexpected plume migration. We demonstrate our approach using historical and current groundwater data from the Savannah River Site (SRS) F-Area Seepage Basins to estimate uranium and tritium concentrations. The results show that the developed method can provide reliable estimates of contaminant

  12. Inexact Socio-Dynamic Modeling of Groundwater Contamination Management

    Science.gov (United States)

    Vesselinov, V. V.; Zhang, X.

    2015-12-01

    Groundwater contamination may alter the behaviors of the public such as adaptation to such a contamination event. On the other hand, social behaviors may affect groundwater contamination and associated risk levels such as through changing ingestion amount of groundwater due to the contamination. Decisions should consider not only the contamination itself, but also social attitudes on such contamination events. Such decisions are inherently associated with uncertainty, such as subjective judgement from decision makers and their implicit knowledge on selection of whether to supply water or reduce the amount of supplied water under the scenario of the contamination. A socio-dynamic model based on the theories of information-gap and fuzzy sets is being developed to address the social behaviors facing the groundwater contamination and applied to a synthetic problem designed based on typical groundwater remediation sites where the effects of social behaviors on decisions are investigated and analyzed. Different uncertainties including deep uncertainty and vague/ambiguous uncertainty are effectively and integrally addressed. The results can provide scientifically-defensible decision supports for groundwater management in face of the contamination.

  13. Field demonstration of ex situ biological treatability of contaminated groundwater at the Strachan gas plant

    International Nuclear Information System (INIS)

    Kurz, M.D.; Stepan, D.J.

    1997-03-01

    A multi-phase study was conducted to deal with the issues of groundwater and soil contamination by sour gas processing plants in Alberta. Phase One consisted of a review of all soil and groundwater monitoring data submitted to Alberta Environment by sour gas plants in accordance with the Canadian Clean Water Act. The current phase involves the development, evaluation and demonstration of selected remediation technologies to address subsurface contamination of sediments and groundwater at sour gas treatment plants with special attention to the presence of natural gas condensate in the subsurface. Results are presented from a pilot-scale biological treatability test that was performed at the Gulf Strachan Natural Gas Processing Plant in Rocky Mountain House, Alberta, where contaminated groundwater from the plant was being pumped to the surface through many recovery wells to control contaminant migration. The recovered groundwater was directed to a pump-and-treat system that consisted of oil-water separation, iron removal, hardness removal, and air stripping, before being reinjected. The pilot-scale biological treatability testing was conducted to evaluate process stability in treating groundwater without pretreatment for iron and hardness reduction and to evaluate the removal of organic contaminants. Results of a groundwater characterization analysis are discussed. Chemical characteristics of the groundwater at the Strachan Gas Plant showed that an ex situ remediation technology would address the dissolved volatile and semi-volatile organic contamination from natural gas condensates, as well as the nitrogenous compounds resulting from the use of amine-based process chemicals. 4 refs., 5 tabs., 4 figs

  14. Evaluation of organic contamination in urban groundwater surrounding a municipal landfill, Zhoukou, China.

    Science.gov (United States)

    Han, D M; Tong, X X; Jin, M G; Hepburn, Emily; Tong, C S; Song, X F

    2013-04-01

    This paper investigates the organic pollution status of shallow aquifer sediments and groundwater around Zhoukou landfill. Chlorinated aliphatic hydrocarbons, monocylic aromatic hydrocarbons, halogenated aromatic hydrocarbons, organochlorine pesticides and other pesticides, and polycyclic aromatic hydrocarbons (PAHs) have been detected in some water samples. Among the detected eleven PAHs, phenanthrene, fluorine, and fluoranthene are the three dominant in most of the groundwater samples. Analysis of groundwater samples around the landfill revealed concentrations of PAHs ranging from not detected to 2.19 μg/L. The results show that sediments below the waste dump were low in pollution, and the shallow aquifer, at a depth of 18-30 m, was heavily contaminated, particularly during the wet season. An oval-shaped pollution halo has formed, spanning 3 km from west to east and 2 km from south to north, and mainly occurs in groundwater depths of 2-4 m. For PAH source identification, both diagnostic ratios of selected PAHs and principal component analysis were studied, suggesting mixed sources of pyro- and petrogenic derived PAHs in the Zhoukou landfill. Groundwater table fluctuations play an important role in the distribution of organic pollutants within the shallow aquifer. A conceptual model of leachate migration in the Quaternary aquifers surrounding the Zhoukou landfill has been developed to describe the contamination processes based on the major contaminant (PAHs). The groundwater zone contaminated by leachate has been identified surrounding the landfill.

  15. Modelling tools for integrating geological, geophysical and contamination data for characterization of groundwater plumes

    DEFF Research Database (Denmark)

    Balbarini, Nicola

    the contaminant plume in a shallow and a deep plume. These plumes have different chemical characteristics and different migration paths to the stream. This has implications for the risk assessment of the stream and groundwater in the area. The difficulty of determining groundwater flow paths means that it is also...... receptors, including streams. Key risk assessment parameters, such as contaminant mass discharge estimates, and tools are then used to evaluate the risk. The cost of drilling often makes investigations of large and/or deep contaminant plumes unfeasible. For this reason, it is important to develop cost...... organic compounds, including pharmaceutical compounds and chlorinated ethenes. The correlation between DCIP and organic compounds is indirect and depends on the chemical composition of the contaminant plume and the transport processes. Thus, the correlations are site specific and may change between...

  16. Groundwater contamination and its effect on health in Turkey.

    Science.gov (United States)

    Baba, Alper; Tayfur, Gokmen

    2011-12-01

    The sources of groundwater pollution in Turkey are identified, and pathways of contaminants to groundwater are first described. Then, the effects of groundwater quality on health in Turkey are evaluated. In general, sources of groundwater contamination fall into two main categories: natural and anthropogenic sources. Important sources of natural groundwater pollution in Turkey include geological formations, seawater intrusion, and geothermal fluid(s). The major sources of anthropogenic groundwater contamination are agricultural activities, mining waste, industrial waste, on-site septic tank systems, and pollution from imperfect well constructions. The analysis results revealed that natural contamination due to salt and gypsum are mostly found in Central and Mediterranean regions and arsenic in Aegean region. Geothermal fluids which contain fluoride poses a danger for skeleton, dental, and bone problems, especially in the areas of Denizli, Isparta, and Aydın. Discharges from surface water bodies contaminate groundwater by infiltration. Evidence of such contamination is found in Upper Kızılırmak basin, Gediz basin, and Büyük Melen river basin and some drinking water reservoirs in İstanbul. Additionally, seawater intrusion causes groundwater quality problems in coastal regions, especially in the Aegean coast. Industrial wastes are also polluting surface and groundwater in industrialized regions of Turkey. Deterioration of water quality as a result of fertilizers and pesticides is another major problem especially in the regions of Mediterranean, Aegean, Central Anatolia, and Marmara. Abandoned mercury mines in the western regions of Turkey, especially in Çanakkale, İzmir, Muğla, Kütahya, and Balıkesir, cause serious groundwater quality problems.

  17. Sedimentological analysis of a contaminated groundwater aquifer

    International Nuclear Information System (INIS)

    Towse, D.

    1991-01-01

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

  18. Study of the influence of hydrogeological conditions in the upper aquifer on radionuclide migration from a geological repository using a 2D groundwater flow model

    Energy Technology Data Exchange (ETDEWEB)

    Shestopalov, Vyacheslav; Bohuslavskyy, Alexander; Shybetskyi, Iurii [National Academy of Science of Ukaraine, Kyiv (Ukraine). Radioenvironmental Centre

    2015-07-01

    Results are presented of a case groundwater flow-transport modeling to predict the radionuclide migration from a deep geological repository (DGR) of radioactive waste. The influence of hydrogeological conditions in the upper aquifers of a storey water exchange system on the rate of contaminant migration from the DGR to its natural far-field groundwater discharges (a shallow well and a river) as a general DGR safety condition is considered.

  19. Modeling In Situ Bioremediation of Perchlorate-Contaminated Groundwater

    National Research Council Canada - National Science Library

    Secody, Roland E

    2007-01-01

    .... An innovative technology was recently developed which uses dual-screened treatment wells to mix an electron donor into perchlorate-contaminated groundwater in order to effect in situ bioremediation...

  20. Innovative reactive barrier technologies for regional contaminated groundwater

    NARCIS (Netherlands)

    Merkel, P.; Weiβ, H.; Teutsch, G.; Rijnaarts, H.H.M.

    2000-01-01

    At many industrial sites inadequate waste disposal, leakages and war damages have led to severe groundwater contamination on a regional scale. Standard hydraulic groundwater remediation methods, such as pump-and-treat, in most cases do not lead to satisfactory results, due to the persistence of

  1. Microbial Functional Gene Diversity Predicts Groundwater Contamination and Ecosystem Functioning

    Science.gov (United States)

    Zhang, Ping; Wu, Linwei; Rocha, Andrea M.; Shi, Zhou; Wu, Bo; Qin, Yujia; Wang, Jianjun; Yan, Qingyun; Curtis, Daniel; Ning, Daliang; Van Nostrand, Joy D.; Wu, Liyou; Watson, David B.; Adams, Michael W. W.; Alm, Eric J.; Adams, Paul D.; Arkin, Adam P.

    2018-01-01

    ABSTRACT Contamination from anthropogenic activities has significantly impacted Earth’s biosphere. However, knowledge about how environmental contamination affects the biodiversity of groundwater microbiomes and ecosystem functioning remains very limited. Here, we used a comprehensive functional gene array to analyze groundwater microbiomes from 69 wells at the Oak Ridge Field Research Center (Oak Ridge, TN), representing a wide pH range and uranium, nitrate, and other contaminants. We hypothesized that the functional diversity of groundwater microbiomes would decrease as environmental contamination (e.g., uranium or nitrate) increased or at low or high pH, while some specific populations capable of utilizing or resistant to those contaminants would increase, and thus, such key microbial functional genes and/or populations could be used to predict groundwater contamination and ecosystem functioning. Our results indicated that functional richness/diversity decreased as uranium (but not nitrate) increased in groundwater. In addition, about 5.9% of specific key functional populations targeted by a comprehensive functional gene array (GeoChip 5) increased significantly (P contamination and ecosystem functioning. This study indicates great potential for using microbial functional genes to predict environmental contamination and ecosystem functioning. PMID:29463661

  2. Microbial Functional Gene Diversity Predicts Groundwater Contamination and Ecosystem Functioning

    Directory of Open Access Journals (Sweden)

    Zhili He

    2018-02-01

    Full Text Available Contamination from anthropogenic activities has significantly impacted Earth’s biosphere. However, knowledge about how environmental contamination affects the biodiversity of groundwater microbiomes and ecosystem functioning remains very limited. Here, we used a comprehensive functional gene array to analyze groundwater microbiomes from 69 wells at the Oak Ridge Field Research Center (Oak Ridge, TN, representing a wide pH range and uranium, nitrate, and other contaminants. We hypothesized that the functional diversity of groundwater microbiomes would decrease as environmental contamination (e.g., uranium or nitrate increased or at low or high pH, while some specific populations capable of utilizing or resistant to those contaminants would increase, and thus, such key microbial functional genes and/or populations could be used to predict groundwater contamination and ecosystem functioning. Our results indicated that functional richness/diversity decreased as uranium (but not nitrate increased in groundwater. In addition, about 5.9% of specific key functional populations targeted by a comprehensive functional gene array (GeoChip 5 increased significantly (P < 0.05 as uranium or nitrate increased, and their changes could be used to successfully predict uranium and nitrate contamination and ecosystem functioning. This study indicates great potential for using microbial functional genes to predict environmental contamination and ecosystem functioning.

  3. Characterization of contaminated soil and groundwater surrounding an illegal landfill (S. Giuliano, Venice, Italy) by principal component analysis and kriging

    International Nuclear Information System (INIS)

    Critto, Andrea; Carlon, Claudio; Marcomini, Antonio

    2003-01-01

    Information on soil and groundwater contamination was used to develop a site conceptual model and to identify exposure scenarios. - The characterization of a hydrologically complex contaminated site bordering the lagoon of Venice (Italy) was undertaken by investigating soils and groundwaters affected by the chemical contaminants originated by the wastes dumped into an illegal landfill. Statistical tools such as principal components analysis and geostatistical techniques were applied to obtain the spatial distribution of chemical contaminants. Dissolved organic carbon (DOC), SO 4 2- and Cl - were used to trace the migration of the contaminants from the top soil to the underlying groundwaters. The chemical and hydrogeological available information was assembled to obtain the schematic of the conceptual model of the contaminated site capable to support the formulation of major exposure scenarios, which are also provided

  4. Microbial Functional Gene Diversity Predicts Groundwater Contamination and Ecosystem Functioning.

    Science.gov (United States)

    He, Zhili; Zhang, Ping; Wu, Linwei; Rocha, Andrea M; Tu, Qichao; Shi, Zhou; Wu, Bo; Qin, Yujia; Wang, Jianjun; Yan, Qingyun; Curtis, Daniel; Ning, Daliang; Van Nostrand, Joy D; Wu, Liyou; Yang, Yunfeng; Elias, Dwayne A; Watson, David B; Adams, Michael W W; Fields, Matthew W; Alm, Eric J; Hazen, Terry C; Adams, Paul D; Arkin, Adam P; Zhou, Jizhong

    2018-02-20

    Contamination from anthropogenic activities has significantly impacted Earth's biosphere. However, knowledge about how environmental contamination affects the biodiversity of groundwater microbiomes and ecosystem functioning remains very limited. Here, we used a comprehensive functional gene array to analyze groundwater microbiomes from 69 wells at the Oak Ridge Field Research Center (Oak Ridge, TN), representing a wide pH range and uranium, nitrate, and other contaminants. We hypothesized that the functional diversity of groundwater microbiomes would decrease as environmental contamination (e.g., uranium or nitrate) increased or at low or high pH, while some specific populations capable of utilizing or resistant to those contaminants would increase, and thus, such key microbial functional genes and/or populations could be used to predict groundwater contamination and ecosystem functioning. Our results indicated that functional richness/diversity decreased as uranium (but not nitrate) increased in groundwater. In addition, about 5.9% of specific key functional populations targeted by a comprehensive functional gene array (GeoChip 5) increased significantly ( P contamination and ecosystem functioning. This study indicates great potential for using microbial functional genes to predict environmental contamination and ecosystem functioning. IMPORTANCE Disentangling the relationships between biodiversity and ecosystem functioning is an important but poorly understood topic in ecology. Predicting ecosystem functioning on the basis of biodiversity is even more difficult, particularly with microbial biomarkers. As an exploratory effort, this study used key microbial functional genes as biomarkers to provide predictive understanding of environmental contamination and ecosystem functioning. The results indicated that the overall functional gene richness/diversity decreased as uranium increased in groundwater, while specific key microbial guilds increased significantly as

  5. Screening Approach to the Activation of Soil and Contamination of Groundwater at Linear Proton Accelerator Sites

    CERN Document Server

    Otto, Thomas

    The activation of soil and the contamination of groundwater at proton accelerator sites with the radionuclides 3H and 22Na are estimated with a Monte-Carlo calculation and a conservative soil- and ground water model. The obtained radionuclide concentrations show that the underground environment of future accelerators must be adequately protected against a migration of activation products. This study is of particular importance for the proton driver accelerator in the planned EURISOL facility.

  6. Groundwater geochemistry near the storage sites of low-level radioactive waste: Implications for uranium migration

    Energy Technology Data Exchange (ETDEWEB)

    Gaskova, Olga L.; Boguslavsky, Anatoly E. [Institute of Geology and Mineralogy SB RAS, Ac. Koptyug prosp. 3, Novosibirsk 630090 (Russian Federation)

    2013-07-01

    This paper presents results of detailed sampling of groundwater and surface water near the storage sites of radioactive waste from the Electrochemical Plant ECP (Zelenogorsk, Krasnoyarsk region, Russia) and the Angarsk Electrolysis Chemical Complex AEC (Angarsk, Irkutsk region, Russia), both of which have produced enriched uranium since 1960's. The liquid (LRW) and solid (SRW) radioactive wastes belong to the category of low-level activity waste. The main result is that the uranium is below the recommended MPC for drinking waters in all types of groundwater around the sludge of ECP and AEC. But alkaline nitrate solutions have been penetrating and spreading into the aquifers under the LRW sludge pits. According to our calculations, redox conditions in the groundwater influenced by discharge are controlled by the couple NO{sub 3}{sup -}/NO{sub 2}{sup -} that facilitates U(VI) migration. The groundwater under SRW repositories is distinguished by its low mineralization and neutral pH. Co-contaminants, such as Mo, V, and Zr may serve as markers of techno-genous contamination in storage sites of the LRW sludge. (authors)

  7. Complex relationship between groundwater velocity and concentration of radioactive contaminants

    International Nuclear Information System (INIS)

    Kaszeta, F.E.; Bond, F.W.

    1980-01-01

    This paper uses the results from the Multi-component Mass Transport model to examine the complex interrelationship between groundwater velocity and contaminant dispersion, decay, and retardation with regard to their influence on the contaminant concentration distribution as it travels through the geosphere to the biosphere. The rate of transport of contaminants through the geosphere is governed by groundwater velocity, leach rate, and contaminant retardation. The dominant characteristics of the contaminant concentration distribution are inherited during leaching and modified during transport by dilution, dispersion and decay. For a hypothetical non-decaying, non-dispersing contaminant with no retardation properties, the shape of the source term distribution is governed by the groundwater velocity (dilution) and leach rate. This distribution remains unchanged throughout transport. Under actual conditions, however, dispersion, decay and retardation modify the concentration distribution during both leaching and transport. The amount of dispersion is determined by the distance traveled, but it does have a greater peak-reducing influence on spiked distributions than square-shaped distributions. Decay acts as an overall scaling factor on the concentration distribution. Retardation alters the contaminant travel time and therefore indirectly influences the amount of dilution, dispersion and decay. Simple relationships between individual parameters and groundwater velocity as they influence peak concentration do not exist. For those cases where the source term is not solubility-limited and flow past the waste is independent of regional hydrologic conditions, a threshold concentration occurs at a specific groundwater velocity where the effects of dilution balance those of dispersion and decay

  8. Dilution and volatilization of groundwater contaminant discharges in streams

    DEFF Research Database (Denmark)

    Aisopou, Angeliki; Bjerg, Poul Løgstrup; Sonne, Anne Thobo

    2015-01-01

    measurement. The solution was successfully applied to published field data obtained in a large and a small Danish stream and provided valuable information on the risk posed by the groundwater contaminant plumes. The results provided by the dilution and volatilization model are very different to those obtained......An analytical solution to describe dilution and volatilization of a continuous groundwater contaminant plume into streams is developed for risk assessment. The location of groundwater plume discharge into the stream (discharge through the side versus bottom of the stream) and different...

  9. Is nutrient contamination of groundwater causing eutrophication of groundwater-fed meadows?

    NARCIS (Netherlands)

    Pieterse, N.M.; Olde Venterink, H.; Schot, P.P.; Verkroost, A.W.M.

    2005-01-01

    There is an ongoing debate as to whether nutrient contamination of groundwater under agricultural fields may cause nutrient-enrichment and subsequent eutrophication in discharge areas. Often, there is only circumstantial evidence to support this supposition (proximity of agricultural fields,

  10. Computer modelling of contaminant migration in natural disperse media

    International Nuclear Information System (INIS)

    Kundas, S.P.; Gishkelyuk, I.A.; Khil'ko, O.S.

    2012-01-01

    The theoretical foundations for modeling of the contaminants migration in natural disperses media taking into account interconnected heat and moisture transport are developed. The calculation of mass transfer parameters based on adsorption isotherms of water and thermodynamic equations in the developed mathematical models. The artificial neural networks use to predict migration of contaminants in natural disperse media is proposed. The developed software package is presented and results of practical application of models and software are discussed. (authors)

  11. Groundwater pumping effects on contaminant loading management in agricultural regions.

    Science.gov (United States)

    Park, Dong Kyu; Bae, Gwang-Ok; Kim, Seong-Kyun; Lee, Kang-Kun

    2014-06-15

    Groundwater pumping changes the behavior of subsurface water, including the location of the water table and characteristics of the flow system, and eventually affects the fate of contaminants, such as nitrate from agricultural fertilizers. The objectives of this study were to demonstrate the importance of considering the existing pumping conditions for contaminant loading management and to develop a management model to obtain a contaminant loading design more appropriate and practical for agricultural regions where groundwater pumping is common. Results from this study found that optimal designs for contaminant loading could be determined differently when the existing pumping conditions were considered. This study also showed that prediction of contamination and contaminant loading management without considering pumping activities might be unrealistic. Motivated by these results, a management model optimizing the permissible on-ground contaminant loading mass together with pumping rates was developed and applied to field investigation and monitoring data from Icheon, Korea. The analytical solution for 1-D unsaturated solute transport was integrated with the 3-D saturated solute transport model in order to approximate the fate of contaminants loaded periodically from on-ground sources. This model was further expanded to manage agricultural contaminant loading in regions where groundwater extraction tends to be concentrated in a specific period of time, such as during the rice-growing season, using a method that approximates contaminant leaching to a fluctuating water table. The results illustrated that the simultaneous management of groundwater quantity and quality was effective and appropriate to the agricultural contaminant loading management and the model developed in this study, which can consider time-variant pumping, could be used to accurately estimate and to reasonably manage contaminant loading in agricultural areas. Copyright © 2014 Elsevier Ltd. All

  12. Vertical contamination in the unconfined groundwater at the Hanford Site, Washington

    International Nuclear Information System (INIS)

    Eddy, P.A.; Myers, D.A.; Raymond, J.R.

    1978-08-01

    Disposal to the ground at Hanford of large volumes of low- and intermediate-level wastes in the local unconfined groundwater flow system has raised concern about the movement and distribution of this waste. Previous work produced information on the horizontal movement of the waste, but little or no information exists on its vertical distribution within the unconfined groundwater flow system. In 1975 Phase I of a study was started to determine the vertical distribution of contaminants in three existing wells (699-28-40, 699-31-31, and 699-37-43). Because of negative results, only one well that produced positive results (699-31-31) was chosen for Phase II. Phase II consisted of tests conducted on this well by a testing company, with samples cross-checked by two different laboratories. Phase III was a cooperative study with Rockwell Hanford Operations, which included the installation, testing, and sampling of piezometers. The data were then analyzed using predictive codes and models in order to determine if vertical movement did occur. The present groundwater flow system shows some vertical contamination. However, concentrations are relatively higher near the surface of the flow system, indicating possible radial flow patterns from the groundwater mounds known to have developed under the chemical processing area disposal sites. Upward flow from deeper aquifers may be diluting the contaminant and masking a possible downward migration of contaminants

  13. Chemical contamination of groundwater at gas processing plants - the past, the present and the future

    International Nuclear Information System (INIS)

    Wrubleski, R.M.; Drury, C.R.

    1997-01-01

    The chemicals used to remove the sour gas components (primarily H 2 S) from raw gas in the sour gas sweetening processes were discussed. The chemicals, mainly amines and physical absorbents, have been found as contaminants in soil and groundwater at several sites. Studies have been conducted to evaluate the behaviour of some of these chemicals. In particular, the contamination by sulfolane and diisopropanolamine (DIPA) which originate from the Sulfinol R sweetening process, was discussed. Prior to the mid 1970s wastes from these processes were disposed of on site in landfills that were not engineered for groundwater protection. By the mid 1970s the landfills were closed by capping. Many of the gas plant sites were located on elevated terrain where hydraulic gradient was available for downward movement of groundwater and any chemicals contained within. Contaminant movement in fractured bedrock has also affected drinking water. Ground water monitoring began in the mid 1980s to address environmental concerns, focusing on monitoring for potability, metals and organics. It was discovered that most of the plants using the Sulfinol process had groundwater contaminated with sulfolane levels ranging from 1 ppm to over 800 ppm. A research project was developed to determine the soil interaction parameters and biodegradation behaviour of pure sulfolane and DIPA to provide data in order to predict plume migration. Ecotoxicity tests were also performed to verify toxicity effects of sulfolane, DIPA, reclaimer bottoms and observed biodegradation metabolites to bio-organisms and aquatic life in aquatic receptors. 3 refs., 1 tab., 1 fig

  14. In Situ Treatment of Chlorinated Ethene-Contaminated Groundwater Using horizontal Flow Treatment Wells

    National Research Council Canada - National Science Library

    Ferland, Derek

    2000-01-01

    The limitations of conventional containment technologies for groundwater contaminated with chlorinated solvents have motivated development of innovative technologies to achieve national groundwater...

  15. Review of risk from potential emerging contaminants in UK groundwater

    OpenAIRE

    Stuart, Marianne; Lapworth, Dan; Crane, Emily; Hart, Alwyn

    2012-01-01

    This paper provides a review of the types of emerging organic groundwater contaminants (EGCs) which are beginning to be found in the UK. EGCs are compounds being found in groundwater that were previously not detectable or known to be significant and can come from agricultural, urban and rural point sources. EGCs include nanomaterials, pesticides, pharmaceuticals, industrial compounds, personal care products, fragrances, water treatment by-products, flame retardants and surfactants, as well a...

  16. Investigation of radionuclides and anthropic tracer migration in groundwater at the Chernobyl site

    Science.gov (United States)

    Le Gal La Salle, Corinnne; Simonucci, Caroline; Roux, Céline; Bugai, Dmitry; Aquilina, Luc; Fourré, Elise; Jean-Baptiste, Philippe; Labasque, Thierry; Michelot, Jean-Luc; Fifield, Keith; Team Aster Team; Van Meir, Nathalie; Kashparov, Valeriy; Diez, Olivier; Bassot, Sylvain; Lancelot, Joel

    2013-04-01

    Following the reactor 4 explosion of the Chernobyl Nuclear Power Plant (ChNPP), at least 1019 Bq of radionuclides (RN) were released in the environment. In order to protect workers and prevent further atmospheric RN dispersion in the area adjacent to the ChNPP, contaminated wastes including fuel particles, topsoil layer and forest remains were buried in approximately 800 shallow trenches in the sand formation in the Red Forest waste dump site [1]. No containment measures were taken, and since then RN have leaked to the unsaturated zone and to the groundwater. Since 1999, migration of RN in the vicinity of the trench 22 at Red Forest site has been investigated within the frame of the EPIC program carried out by IRSN in collaboration with UIAR and IGS [2, 3]. A plume of 90Sr was shown downgradient from the trench 22 with activites reaching 3750 Bq/L [2]. In 2008, further studies were initiated through the TRASSE research group, based on a collaboration between IRSN and CNRS. These programs aim at combining groundwater dating with RN migration monitoring studies in order to constrain RN transport models [3]. Groundwater residence time was investigated based on 3H/He and CFC. Both tracers led to ages ranging from modern (1-3 y) at 2 m depth below the groundwater table to significantly higher apparent ages of 50-60 y at 27 m below the groundwater table [3]. 36Cl/Cl ratios 2 to 4 orders of magnitude higher than the theoretical natural ratio are measured in groundwater. Similarly, SF6 shows concentrations as high as 1200 pptv while natural concentrations are in the order of 6-7 pptv. Based on apparent groundwater ages, both contaminations are linked to the Chernobyl explosion. Hence those tracers show excellent potential to constrain conservative and reactive transport, respectively. In contrast, 238U/235U ratio down gradient from trench 22 remains similar to the natural ratio. This suggests that either most of the U contained in the trench is in a non soluble form

  17. Use of electromagnetic terrain conductivity measurements to map liquid hazardous waste migration in groundwater

    International Nuclear Information System (INIS)

    Ketelle, R.H.; Pin, F.G.

    1983-11-01

    Electromagnetic conductivity measurements have been used to map apparent ground conductivity in the vicinity of a liquid hazardous waste disposal site. An area of approximately 12 ha (30 acres) was surveyed. Approximately 600 conductivity measurements were obtained to prepare a conductivity map of the site. Conductivity measurments in the area correlate with specific conductance measurements of surface and groundwater samples. Contouring of the conductivity data showed the precise location of contaminant migration pathways in the subsurface. A complex contaminant plume was defined by the conductivity survey. Conductivity values obtained reflected anisotropic characteristics related to local bedrock structure. Anisotropy characteristics and the use of different instrument configurations indicated semiquantitatively the depth of the high conductivity zone and the direction of flow

  18. Influence of the tension-saturated zone on contaminant migration in shallow water-table regimes

    International Nuclear Information System (INIS)

    Gillham, R.W.

    1982-01-01

    Groundwater discharge represents a major pathway for the return to the biosphere of contaminants that are released to the subsurface environment. An understanding of the transport processes in groundwater discharge zones is therefore an important consideration in pathway analyses associated with the environmental assessment of proposed waste-management facilities. Shallow water tables are a common characteristic of groundwater discharge zones, particularly in humid climatic regions. In this paper, the results of field tests, laboratory tests and numerical simulations are used to show that under shallow water-table conditions, the zone of tension saturation can result in a rapid and highly disproportionate water-table response to precipitation. It is further shown that this response can result in complex migration patterns that would not be predicted by the classical approaches to solute transport modelling and that the response could result in large and highly transient inputs to surface water

  19. Public health risk assessment of groundwater contamination in Batman, Turkey.

    Science.gov (United States)

    Nalbantcilar, M Tahir; Pinarkara, Sukru Yavuz

    2016-08-01

    In this study, a comprehensive analysis of groundwater was performed to assess contamination and phenol content in Batman, Turkey, particularly in residential areas near agriculture, livestock and oil industry facilities. From these areas, where potentially contaminated groundwater used for drinking and irrigation threatens public health, 30 groundwater samples were collected and analyzed for heavy metal concentrations (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Na, Ni, NO3, P, Pb, phenol, S, Sb, Se, SO4, Sr, U, and Zn). Compared with the standards of the Environmental Protection Agency, Al, Fe, and Mn concentrations in groundwater exceeded secondary drinking water regulations, NO3 concentrations were high for maximum contaminant levels, and As, Pb, and U concentrations exceeded maximum contaminant level goals in all samples. Ni, Sb, and Se concentrations also exceeded limits set by the Turkish Standards Institution. Nearly all samples revealed concentrations of Se, Sb, Hg, and phenol due to nearby petroleum refineries, oil storage plants, and agricultural and livestock areas. The results obtained from this study indicate that the groundwater in Batman contains elements in concentrations that approach or exceed limits and thus threatens public health with increased blood cholesterol, decreased blood sugar, and circulatory problems.

  20. Hydrodynamic analysis application of contaminated groundwater remediation to oil hydrocarbons

    Directory of Open Access Journals (Sweden)

    Pajić Predrag R.

    2017-01-01

    Full Text Available In this paper, the application of the hydrodynamic analysis in the selected ‘pumping and treatment’ remediation method of groundwater hydrocarbon pollution in the case of the Pancevo oil refinery is examined. The applied hydrodynamic analysis represents a regular and necessary approach in modern hydrogeology. Previous chemical analysis of soil and groundwater samples at observation objects revealed their pollution by oil products. New researches included the constraction of 12 piezometric boreholes of varying depths, geoelectric soil sounding, ‘in situ’ measurement of the present contaminant, detected as a hydrophobic phase of LNAPL, chemical analysis of soil and groundwater samples with emphasis on total petroleum hydrocarbons (TPH content, total fats and mineral oils, mercury cations and other characteristic compounds, etc. These researches define the volume of contamination issued by the ‘light’ (LNAPL contamination phase. The selected remediation method for this type of pollution is the ‘Pump and Treat’ method, which implies the pumping of contaminated groundwater from aquifer and their subsequent treatment. A hydrodynamic method was used to select the optimal hydrotechnical solution for LNAPL extraction. On the mathematical model, the prediction calculations for two variant solutions were carried out (‘hydraulic isolation’ and complex for the application of groundwater contamination remediation characterized as front pollution substance (by extraction and injection wells or infiltration pool. By extraction wells performing, it would be possible to remove the LNAPL from the surface of the water with special pumps-skimmers. The importance of the hydrodynamic method application is, in addition to the hydrotechnical solution selection for the LNAPL drainage, the provision of quality basis for the dimensioning of these objects based on the results of the groundwater balance.

  1. Review: Micro-organic contaminants in groundwater in China

    Science.gov (United States)

    Dong, Weihong; Xie, Wei; Su, Xiaosi; Wen, Chuanlei; Cao, Zhipeng; Wan, Yuyu

    2018-03-01

    Micro-organic contaminants (MOs) in groundwater, which may have adverse effects on human health and ecosystems worldwide, are gaining increased attention in China. A great deal of research has been conducted to investigate their sources, occurrences and behavior in aquifers. This paper reviews the main sources, distribution, concentrations and behavior of a wide range of MOs in groundwater in China. These MOs include well-established persistent organic pollutants—polycyclic aromatic hydrocarbons (PAHs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyls (PCBs), endocrine disrupting chemicals (poly brominated diphenyl ethers (PBDEs), phthalic acid esters (PAEs), bisphenol A (BPA)—and some contaminants of emerging concern such as pharmaceutical and personal care products (antibiotics, caffeine, shampoos) and perfluorinated compounds (PFCs). The results reveal that the main MOs in groundwater are PAHs, organochlorine pesticides (OCPs), PBDEs, PAEs, and antibiotics. Moreover, some PFCs such as perfluorobutane sulfonic acid (PFBS), perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) have only recently been observed in groundwater as emerging organic contaminants. Additionally, most MOs are distributed in populated and industrialized areas such as the southeast coast of China. Finally, industrial emissions, wastewater treatment plant effluents and agricultural wastewater are found to be dominant sources of MOs in groundwater. Based on the existing pollution levels, regulation and amelioration of MOs are warranted.

  2. Arsenic contamination of groundwater in Bangladesh

    International Nuclear Information System (INIS)

    2003-01-01

    Shallow groundwater with high arsenic concentrations from naturally occurring sources is the primary source of drinking water for millions of people in Bangladesh. It has resulted in a major public health crisis with as many as 70 million people possibly at risk. The International Atomic Energy Agency (IAEA) is supporting international efforts and the Government of Bangladesh to find alternative, safe and sustainable sources of drinking water. (IAEA)

  3. Potential contamination of groundwater in the World Heritage Site of ...

    African Journals Online (AJOL)

    The rapid population growth, high levels of tourism and poor sewage waste disposal (at least for the foreseeable future) in St. Katherine have resulted in potential contamination of groundwater and subsequent high risk to human health. To evaluate the safety of well water for human use in St. Katherine, water samples were ...

  4. Biomarkers study in rainbow trout exposed to industrially contaminated groundwater

    Directory of Open Access Journals (Sweden)

    Nadjet Benchalgo

    2014-03-01

    Full Text Available The spill of liquid industrial waste from chemical and petrochemical industries in Mercier lagoons located 20 km south of Montreal, Quebec, caused a major groundwater contamination by industrial contaminants. The aim of this study was to investigate the toxic effects of Mercier groundwater, following 4 and 14 days of exposure to graded concentrations from three wells at increasing distances 1.2, 2.7 and 5.4 km from the source of contamination. Rainbow trout were examined for several biomarkers of defense [ethoxyresorufin O-deethylase (EROD and gluthatione S-transferase (GST activities] and those of tissue damage [lipid peroxidation (LPO and DNA strand breaks]. The results showed that EROD activity was significantly enhanced in hepatic tissue at 1.2 and 5.4 km, whereas inhibition in activity was observed in group at 2.7 km. Therefore, GST activity was significantly increased at 3.1% concentration for the 2.7 km well. No change in LPO was observed. However, a significant induction of DNA strand breaks in liver was obtained at each distance. In conclusion, the data suggest that the release of these contaminants in groundwater leads to increased biotransformation for coplanar aromatic hydrocarbons and DNA damage in groundwater.

  5. Sampling art for ground-water monitoring wells in nuclide migration

    International Nuclear Information System (INIS)

    Liu Wenyuan; Tu Guorong; Dang Haijun; Wang Xuhui; Ke Changfeng

    2010-01-01

    Ground-Water sampling is one of the key parts in field nuclide migration. The objective of ground-water sampling program is to obtain samples that are representative of formation-quality water. In this paper, the ground-water sampling standards and the developments of sampling devices are reviewed. We also designed the sampling study projects which include the sampling methods, sampling parameters and the elementary devise of two types of ground-Water sampling devices. (authors)

  6. Potential effect of natural gas wells on alluvial groundwater contamination at the Kansas City Plant

    Energy Technology Data Exchange (ETDEWEB)

    Pickering, D.A.; Laase, A.D. [Oak Ridge National Lab., TN (United States); Locke, D.A. [Oak Ridge Inst. for Science and Education, TN (United States)

    1993-05-01

    This report is the result of a request for further information about several abandoned natural gas wells at the US Department of Energy`s Kansas City Plant (KCP). The request was prompted by an old map showing several, possibly eight, natural gas wells located under or near what is now the southeast corner of the Main Manufacturing Building at KCP. Volatile organic compound contamination in the alluvial aquifer surrounding the gas wells might possibly contaminate the bedrock aquifer if the gas wells still exist as conduits. Several circumstances exist that make it doubtful that contamination is entering the bedrock aquifers: (1) because regional groundwater flow in the bedrock beneath the KCP is expected to be vertically upward, contaminants found in the alluvial aquifer should not migrate down the old wells; (2) because of the low hydraulic conductivity of the bedrock units, contaminant transport would be extremely slow if the contaminants were migrating down the wells; and (3) casing, apparently set through the alluvium in all of the wells, would have deteriorated and may have collapsed; if the casing collapsed, the silty clays in the alluvium would also collapse and seal the well. No definitive information has been discovered about the exact location of the wells. No further search for or consideration of the old gas wells is recommended.

  7. Potential effect of natural gas wells on alluvial groundwater contamination at the Kansas City Plant

    Energy Technology Data Exchange (ETDEWEB)

    Pickering, D.A.; Laase, A.D. (Oak Ridge National Lab., TN (United States)); Locke, D.A. (Oak Ridge Inst. for Science and Education, TN (United States))

    1993-05-01

    This report is the result of a request for further information about several abandoned natural gas wells at the US Department of Energy's Kansas City Plant (KCP). The request was prompted by an old map showing several, possibly eight, natural gas wells located under or near what is now the southeast corner of the Main Manufacturing Building at KCP. Volatile organic compound contamination in the alluvial aquifer surrounding the gas wells might possibly contaminate the bedrock aquifer if the gas wells still exist as conduits. Several circumstances exist that make it doubtful that contamination is entering the bedrock aquifers: (1) because regional groundwater flow in the bedrock beneath the KCP is expected to be vertically upward, contaminants found in the alluvial aquifer should not migrate down the old wells; (2) because of the low hydraulic conductivity of the bedrock units, contaminant transport would be extremely slow if the contaminants were migrating down the wells; and (3) casing, apparently set through the alluvium in all of the wells, would have deteriorated and may have collapsed; if the casing collapsed, the silty clays in the alluvium would also collapse and seal the well. No definitive information has been discovered about the exact location of the wells. No further search for or consideration of the old gas wells is recommended.

  8. Potential effect of natural gas wells on alluvial groundwater contamination at the Kansas City Plant

    International Nuclear Information System (INIS)

    Pickering, D.A.; Laase, A.D.; Locke, D.A.

    1993-05-01

    This report is the result of a request for further information about several abandoned natural gas wells at the US Department of Energy's Kansas City Plant (KCP). The request was prompted by an old map showing several, possibly eight, natural gas wells located under or near what is now the southeast corner of the Main Manufacturing Building at KCP. Volatile organic compound contamination in the alluvial aquifer surrounding the gas wells might possibly contaminate the bedrock aquifer if the gas wells still exist as conduits. Several circumstances exist that make it doubtful that contamination is entering the bedrock aquifers: (1) because regional groundwater flow in the bedrock beneath the KCP is expected to be vertically upward, contaminants found in the alluvial aquifer should not migrate down the old wells; (2) because of the low hydraulic conductivity of the bedrock units, contaminant transport would be extremely slow if the contaminants were migrating down the wells; and (3) casing, apparently set through the alluvium in all of the wells, would have deteriorated and may have collapsed; if the casing collapsed, the silty clays in the alluvium would also collapse and seal the well. No definitive information has been discovered about the exact location of the wells. No further search for or consideration of the old gas wells is recommended

  9. Slow arsenic poisoning of the contaminated groundwater users

    International Nuclear Information System (INIS)

    Uddin, M. M.; Harun-Ar-Rashid, A. K. M.; Hossain, S. M.; Hafiz, M. A.; Nahar, K.; Mubin, S. H.

    2006-01-01

    This paper gives impact of Arsenic contaminated water on human health as well as overview of the extent and severity of groundwater arsenic contamination in Bangladesh. Scalp hair is the most important part of the human body to monitor the accumulation of this type of poison. Therefore, an experiment has been carried out by Neutron Activation Analysis at Atomic Energy Research Establishment , Savar, Dhaka, Bangladesh on human hair of corresponding tube well water users of these areas to determine the total accumulation of arsenic to their body. Hair samples collected from the region where the groundwater was found highly contaminated with arsenic. The obtained results of arsenic concentration in the lower age (Hb) categories of users (below 12 years of age users) is in the range of 0.33 to 3.29 μg/g (ppm) and that in the Hu categories (upper 12 years of age users) is 0.47 to 6.64 μg/g (ppm). Where as maximum permissible range is 1 ppm certified from WHO. Results show that the peoples are highly affected where the groundwater is highly contaminated with arsenic and acts as the primary source of arsenic poisoning among the peoples of those areas. The results indicate that human population is affected with arsenic locally using the contaminated water for a long time

  10. Passive treatment of wastewater and contaminated groundwater

    Science.gov (United States)

    Phifer, Mark A.; Sappington, Frank C.; Millings, Margaret R.; Turick, Charles E.; McKinsey, Pamela C.

    2007-11-06

    A bioremediation system using inorganic oxide-reducing microbial consortia for the treatment of, inter alia coal mine and coal yard runoff uses a containment vessel for contaminated water and a second, floating phase for nutrients. Biodegradable oils are preferred nutrients.

  11. Radionuclide migration in the Chernobyl contamination zone

    International Nuclear Information System (INIS)

    Golosov, V.N.; Panin, A.V.; Ivanova, N.N.

    1998-01-01

    It is well known that fallout of 137 Cs reaching the land soils with precipitation was rapidly and tightly sorbed to the fine fraction of sediment or soils. The majority of the 137 Cs is retained in the top few centimetres of the soil or sediment profiles (Loughran et al, 1993, Owens et al, 1996). In the absence of strong variations in precipitation over a relatively small area the total bomb-derived 137 Cs fallout can assumed to be spatial uniform. The Chernobyl 137 Cs fallout was mostly connected with one or two rains. So the spatial variability of this 137 Cs can be higher. Furthermore because the explosion on the Chernobyl nuclear plant happen together with fire, a lot of ashes particles with radionuclide were distributed within vast areas. So even microvariability of Chernobyl 137 Cs can be very high in some places. The horizontal migration of 137 Cs connects with soil erosion processes that dominate on the agricultural lands of the Central Russia. The main goal of this investigation is to evaluate the caesium-137 horizontal and vertical migration within typical landscape of the Central Russia 11 years after the Chernobyl accident

  12. The aftermath of the Fukushima nuclear accident: Measures to contain groundwater contamination

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, Adrian H., E-mail: adgallardo@geowater.com.au [CONICET (Argentina National Scientific and Technical Research Council), San Luis National University, FCFMyN, Department of Geology, San Luis 5700 (Argentina); Marui, Atsunao [AIST Geological Survey of Japan, Geo-Resources and Environment Institute, Groundwater Research Group, Ibaraki-ken, Tsukuba 305-8567 (Japan)

    2016-03-15

    Several measures are being implemented to control groundwater contamination at the Fukushima Daiichi Nuclear Plant. This paper presents an overview of work undertaken to contain the spread of radionuclides, and to mitigate releases to the ocean via hydrological pathways. As a first response, contaminated water is being held in tanks while awaiting treatment. Limited storage capacity and the risk of leakage make the measure unsustainable in the long term. Thus, an impervious barrier has been combined with a drain system to minimize the discharge of groundwater offshore. Caesium in seawater at the plant port has largely dropped, although some elevated concentrations are occasionally recorded. Moreover, a dissimilar decline of the radioactivity in fish could indicate additional sources of radionuclides intake. An underground frozen shield is also being constructed around the reactors. This structure would reduce inflows to the reactors and limit the interaction between fresh and contaminated waters. Additional strategies include groundwater abstraction and paving of surfaces to lower water levels and further restrict the mobilisation of radionuclides. Technical difficulties and public distrust pose an unprecedented challenge to the site remediation. Nevertheless, the knowledge acquired during the initial work offers opportunities for better planning and more rigorous decisions in the future. - Highlights: • Measures are being undertaken to manage groundwater contamination in Fukushima. • Methods focus on isolating the source and controlling the radionuclides migration. • Wastewater is being temporarily held in tanks for treatment. • Impervious walls inhibit the transport of contaminants toward the ocean. • Paving and pumping further mitigate the dispersion of pollutants by water.

  13. Understanding shallow groundwater contamination in Bwaise slum, Kampala, Uganda

    Science.gov (United States)

    Nyenje, P. M.; Havik, J.; Foppen, J. W.; Uhlenbrook, S.

    2012-04-01

    Groundwater in unsewered urban areas is heavily contaminated by onsite sanitation activities and is believed to be an important source of nutrients ex-filtrating into streams and thus contributing to eutrophication of Lakes in urban areas. Currently the fate of nutrients and especially phosphorus leached into groundwater in such areas is not well known. In this study, we undertook an extensive investigation of groundwater in Bwaise slum, Kampala Uganda to understand the distribution and fate of sanitation-related nutrients N and P that are leached into groundwater. Transects of monitoring wells were installed in Bwaise slum and downstream of the slum. From these wells, water levels were measured and water quality analyses done to understand the distribution and composition of the nutrients, how they evolve downstream and the possible subsurface processes affecting their fate during transport. These findings are necessary to evaluate the risk of eutrophication posed by unsewered areas in urban cities and to design/implement sanitation systems that will effectively reduce the enrichment of these nutrients in groundwater. Key words: fate, groundwater, nutrients, processes, slums

  14. Nitrate contamination of groundwater: A conceptual management framework

    International Nuclear Information System (INIS)

    Almasri, Mohammad N.

    2007-01-01

    In many countries, public concern over the deterioration of groundwater quality from nitrate contamination has grown significantly in recent years. This concern has focused increasingly on anthropogenic sources as the potential cause of the problem. Evidence indicates that the nitrate (NO 3 ) levels routinely exceed the maximum contaminant level (MCL) of 10 mg/l NO 3 -N in many aquifer systems that underlie agriculture-dominated watersheds. Degradation of groundwater quality due to nitrate pollution along with the increasing demand for potable water has motivated the adoption of restoration actions of the contaminated aquifers. Restoration efforts have intensified the dire need for developing protection alternatives and management options such that the ultimate nitrate concentrations at the critical receptors are below the MCL. This paper presents a general conceptual framework for the management of groundwater contamination from nitrate. The management framework utilizes models of nitrate fate and transport in the unsaturated and saturated zones to simulate nitrate concentration at the critical receptors. To study the impact of different management options considering both environmental and economic aspects, the proposed framework incorporates a component of a multi-criteria decision analysis. To enhance spatiality in model development along with the management options, the utilization of a land use map is depicted for the allocation and computation of on-ground nitrogen loadings from the different sources

  15. Comparative metagenomics reveals impact of contaminants on groundwater microbiomes

    Directory of Open Access Journals (Sweden)

    Christopher L Hemme

    2015-10-01

    Full Text Available To understand patterns of geochemical cycling in pristine versus contaminated groundwater ecosystems, pristine shallow groundwater (FW301 and contaminated groundwater (FW106 samples from the Oak Ridge Integrated Field Research Center (OR-IFRC were sequenced and compared to each other to determine phylogenetic and metabolic difference between the communities. Proteobacteria (e.g., Burkholderia, Pseudomonas are the most abundant lineages in the pristine community, though a significant proportion (>55% of the community is composed of poorly characterized low abundance (individually <1% lineages. The phylogenetic diversity of the pristine community contributed to a broader diversity of metabolic networks than the contaminated community. In addition, the pristine community encodes redundant and mostly complete geochemical cycles distributed over multiple lineages and appears capable of a wide range of metabolic activities. In contrast, many geochemical cycles in the contaminated community appear truncated or minimized due to decreased biodiversity and dominance by Rhodanobacter populations capable of surviving the combination of stresses at the site. These results indicate that the pristine site contains more robust and encodes more functional redundancy than the stressed community, which contributes to more efficient nutrient cycling and adaptability than the stressed community.

  16. A generic model of contaminant migration from uranium tailings impoundments

    International Nuclear Information System (INIS)

    Shepherd, T.A.; Brown, S.E.

    1982-01-01

    This paper presents an analytical hydrogeochemical model based upon acid consumption-neutralization front movement. The development of contaminant plumes is discussed and distinct zones within these plumes are identified and characterized. The most important process influencing the rate and extent of contaminant migration at acid-leach uranium tailings impoundments is the neutralization of seepage water by soils along ground water flow paths. The chemical characteristics of the ground water is determined in order to identify and characterize zones within migrating plumes of tailings-derived water. It is concluded that the characterization of specific zones is useful in the interpretation of existing conditions, in the evaluation of future migration, and in the determination of appropriate models for the specific situation

  17. Emerging contaminants: strategies for the assessment of emerging groundwater contaminants 

    OpenAIRE

    Stuart, Marianne; Lapworth, Dan; Manamsa, Katya; Crane, Emily; White, Debbie

    2016-01-01

    Emerging contaminants in groundwater are important. An increasing range of compounds is being detected Urban areas show impact of sewage and industrial wastewater. Some ECs are probably no threat to drinking water at such µg/L concentrations, e.g. caffeine. Others may prove to be in the future. There is little information on their impact on other groundwater receptors in the environment. We are still far from understanding which of these compounds could be important

  18. Arsenic Groundwater Contamination in Bengal: a Coupled Geochemical and Geophysical Study

    Science.gov (United States)

    Charlet, L.; Ansari, A. A.; Dietrich, M.; Latscha, A.; LeBeux, A.; Chatterjee, D.; Mallik, S. B.

    2001-05-01

    Arsenic contamination in drinking water is a problem of great concern in Ganges delta region, and could be one of the largest natural calamity in the world. In the present study, a contamination plume located in the Lalpur area (Chakdaha Block, Nadia District, West Bengal, India) was studied. A coupled geochemical and geophysical approach was employed to understand the mechanism of arsenic mobilisation from the sediments to groundwater, as a first step towards a global explanation of the phenomenon for other contaminated areas in the Ganges delta. The groundwater As concentration, in the 10 km x 10 km studied area, ranges from 10 to 500 ppb. In situ chemical speciation of arsenic was carried out and various geochemical parameters were measured in representative contaminated wells to interpret the mobilization mechanism in terms of redox kinetics. Through geophysical investigations, subsurface lithology, sediment depositional and geomorphological characteristics were determined and correlated with the arsenic contamination processes. From a geomorphological viewpoint, the contaminated area is located in an abandoned paleochannel of the Hooghly river, interpreted as the active site of deposition of fine sediments which were preserved as clay pockets at certain depths. These clay pockets are rich in organic matter, which may be the driving force for redox potential change and thus, may have driven the mobilisation of arsenic in groundwater. The clay pockets rich in organic matter presumably represent the major reservoir where arsenic is sitting and getting released due to redox mechanism. They are sampled at present. A piezometric depression cone characterized by a radial groundwater flow is located underneath the highly populated Lalpur area. The arsenic plume appears to migrate from the Hooghly river towards the cone of depression following the water flowpath, and this shall be verified in forthcoming field campaigns. As (III) constitutes 42 % of the total As

  19. Groundwater arsenic contamination in Bangladesh-21 Years of research.

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Mukherjee, Amitava; Alauddin, Mohammad; Hassan, Manzurul; Dutta, Rathindra Nath; Pati, Shymapada; Mukherjee, Subhash Chandra; Roy, Shibtosh; Quamruzzman, Quazi; Rahman, Mahmuder; Morshed, Salim; Islam, Tanzima; Sorif, Shaharir; Selim, Md; Islam, Md Razaul; Hossain, Md Monower

    2015-01-01

    Department of Public Health Engineering (DPHE), Bangladesh first identified their groundwater arsenic contamination in 1993. But before the international arsenic conference in Dhaka in February 1998, the problem was not widely accepted. Even in the international arsenic conference in West-Bengal, India in February, 1995, representatives of international agencies in Bangladesh and Bangladesh government attended the conference but they denied the groundwater arsenic contamination in Bangladesh. School of Environmental Studies (SOES), Jadavpur University, Kolkata, India first identified arsenic patient in Bangladesh in 1992 and informed WHO, UNICEF of Bangladesh and Govt. of Bangladesh from April 1994 to August 1995. British Geological Survey (BGS) dug hand tube-wells in Bangladesh in 1980s and early 1990s but they did not test the water for arsenic. Again BGS came back to Bangladesh in 1992 to assess the quality of the water of the tube-wells they installed but they still did not test for arsenic when groundwater arsenic contamination and its health effects in West Bengal in Bengal delta was already published in WHO Bulletin in 1988. From December 1996, SOES in collaboration with Dhaka Community Hospital (DCH), Bangladesh started analyzing hand tube-wells for arsenic from all 64 districts in four geomorphologic regions of Bangladesh. So far over 54,000 tube-well water samples had been analyzed by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). From SOES water analysis data at present we could assess status of arsenic groundwater contamination in four geo-morphological regions of Bangladesh and location of possible arsenic safe groundwater. SOES and DCH also made some preliminary work with their medical team to identify patients suffering from arsenic related diseases. SOES further analyzed few thousands biological samples (hair, nail, urine and skin scales) and foodstuffs for arsenic to know arsenic body burden and people sub

  20. Chemical contamination of groundwater at gas processing plants - the past, the present and the future

    Energy Technology Data Exchange (ETDEWEB)

    Wrubleski, R.M.; Drury, C.R. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre; Sevigny, J.H. [Komex Consultants Ltd., Calgary, AB (Canada)

    1997-12-31

    The chemicals used to remove the sour gas components (primarily H{sub 2}S) from raw gas in the sour gas sweetening processes were discussed. The chemicals, mainly amines and physical absorbents, have been found as contaminants in soil and groundwater at several sites. Studies have been conducted to evaluate the behaviour of some of these chemicals. In particular, the contamination by sulfolane and diisopropanolamine (DIPA) which originate from the Sulfinol{sup R} sweetening process, was discussed. Prior to the mid 1970s wastes from these processes were disposed of on site in landfills that were not engineered for groundwater protection. By the mid 1970s the landfills were closed by capping. Many of the gas plant sites were located on elevated terrain where hydraulic gradient was available for downward movement of groundwater and any chemicals contained within. Contaminant movement in fractured bedrock has also affected drinking water. Ground water monitoring began in the mid 1980s to address environmental concerns, focusing on monitoring for potability, metals and organics. It was discovered that most of the plants using the Sulfinol process had groundwater contaminated with sulfolane levels ranging from 1 ppm to over 800 ppm. A research project was developed to determine the soil interaction parameters and biodegradation behaviour of pure sulfolane and DIPA to provide data in order to predict plume migration. Ecotoxicity tests were also performed to verify toxicity effects of sulfolane, DIPA, reclaimer bottoms and observed biodegradation metabolites to bio-organisms and aquatic life in aquatic receptors. 3 refs., 1 tab., 1 fig.

  1. Remediation of TCE-contaminated groundwater using nanocatalyst and bacteria.

    Science.gov (United States)

    Kang, Ser Ku; Seo, Hyunhee; Sun, Eunyoung; Kim, Inseon; Roh, Yul

    2011-08-01

    The objective of this study was to develop and evaluate the remediation of trichloroethene (TCE)-contaminated groundwater using both a nanocatalyst (bio-Zn-magnetite) and bacterium (similar to Clostridium quinii) in anoxic environments. Of the 7 nanocatalysts tested, bio-Zn-magnetite showed the highest TCE dechlorination efficiency, with an average of ca. 90% within 8 days in a batch experiment. The column tests confirmed that the application of bio-Zn-magnetite in combination with the bacterium achieved high degradation efficiency (ca. 90%) of TCE within 5 days compared to the nanocatalyst only, which degraded only 30% of the TCE. These results suggest that the application of a nanocatalyst and the bacterium have potential for the remediation of TCE-contaminated groundwater in subsurface environments.

  2. Groundwater protection from cadmium contamination by permeable reactive barriers

    Energy Technology Data Exchange (ETDEWEB)

    Di Natale, F. [Dipartimento di Ingegneria chimica, Universita di Federico II, P.le Tecchio, 80-80125 Naples (Italy)], E-mail: fdinatal@unina.it; Di Natale, M.; Greco, R. [Centro Interdipartimentale di Ricerca in Ingegneria Ambientale (CIRIAM), Dipartimento di Ingegneria Civile, Seconda Universita di Napoli, via Roma 29-81031 Aversa (Caserta) (Italy); Lancia, A. [Dipartimento di Ingegneria chimica, Universita di Federico II, P.le Tecchio, 80-80125 Naples (Italy); Laudante, C.; Musmarra, D. [Centro Interdipartimentale di Ricerca in Ingegneria Ambientale (CIRIAM), Dipartimento di Ingegneria Civile, Seconda Universita di Napoli, via Roma 29-81031 Aversa (Caserta) (Italy)

    2008-12-30

    This work studies the reliability of an activated carbon permeable reactive barrier in removing cadmium from a contaminated shallow aquifer. Laboratory tests have been performed to characterize the equilibrium and kinetic adsorption properties of the activated carbon in cadmium-containing aqueous solutions. A 2D numerical model has been used to describe pollutant transport within a groundwater and the pollutant adsorption on the permeable adsorbing barrier (PRB). In particular, it has been considered the case of a permeable adsorbing barrier (PAB) used to protect a river from a Cd(II) contaminated groundwater. Numerical results show that the PAB can achieve a long-term efficiency by preventing river pollution for several months.

  3. The Patroon Creek Contamination Migration Investigation

    International Nuclear Information System (INIS)

    Dufek, K.; Zafran, A.; Moore, J.T.

    2006-01-01

    Shaw performed a Site Investigation (SI) for sediment within the Unnamed Tributary of the Patroon Creek, a section of the Patroon Creek, and the Three Mile Reservoir as part of the overall contract with the United States Army Corps of Engineers (USACE) to remediate the Colonie Formerly Utilized Sites Remedial Action Program (FUSRAP) Site. The Unnamed Tributary formerly flowed through the former Patroon Lake, which was located on the main site property and was used as a landfill for radiological and chemical wastes. The objective of the investigation was to determine the absence/presence of radioactive contamination within the three Areas of Concern (AOC). In order to accomplish this objective, Shaw assembled a team to produce a Technical Memorandum that provided an in-depth understanding of the environmental conditions related to the Patroon Creek. Upon completion and analysis of the Technical Memorandum, a Conceptual Site Model (CSM) was constructed and a Technical Planning Program (TPP) was held to develop a Sediment Investigation Work Plan and Sediment Investigation Sampling and Analysis Plan. A total of 32 sample locations were analyzed using on-site direct gamma scans with a Pancake Geiger-Mueller (PGM) instrument for screening purposes and samples were analyzed at on-site and off-site laboratories. The highest interval from each core scan was selected for on-site analysis utilizing a High Purity Germanium (HPGe) detector. Eight of these samples were sent off-site for gamma/alpha spectroscopy confirmation. The data collected during the SI indicated that the U-238 cleanup criterion was exceeded in sediment samples collected from two locations within the Unnamed Tributary but not in downstream sections of Patroon Creek or Three Mile Reservoir. Future actions for impacted sediment in the Unnamed Tributary will be further evaluated. Concentrations of U-238 and Th-232 in all other off-site sediment samples collected from the Unnamed Tributary, Patroon Creek, and

  4. Use of Short Chained Alkylphenols (SCAP in Analysis of Transport Behaviour of Oil Contaminated Groundwater

    Directory of Open Access Journals (Sweden)

    M. Sauter

    2002-06-01

    Full Text Available Shortchained alkylphenols (SCAP represent a main constituent of crude oil and coal liquefaction products. Due to their specific oil/water partitioning behaviour and high aqueous solubility they can be detected in oil exploitation waters and groundwaters affected by various spills near oil pipelines, oil exploitation sites and coal liquefaction plants. New efficient and powerful analytical techniques have been developed that allow the identification of all 34 individual compounds (C0-C3 without derivatisation and in complex matrices. Due to the different physico-chemical properties of the SCAP, differential transport behaviour in groundwater can be observed, changing the relative concentrations of SCAP downgradient in space and time. These characteristic ratios can be employed to derive information on migration direction and the ageing of the source of contamination. A case study is presented to illustrate the use of this new tool.

  5. [Study on the groundwater petroleum contaminant remediation by air sparging].

    Science.gov (United States)

    Wang, Zhi-Qiang; Wu, Qiang; Zou, Zu-Guang; Chen, Hong; Yang, Xun-Chang; Zhao, Ji-Chu

    2007-04-01

    The groundwater petroleum contaminant remediation effect by air sparging was investigated in an oil field. The results show that the soil geological situation has great influence on the air distribution, and the shape of air distribution is not symmetrical to the air sparging (AS) well as axis. The influence distance in the left of AS well is 6 m, and only 4 m in the right. The petroleum removal rate can reach 70% in the zone with higher air saturation, but only 40% in the zone with lower air saturation, and the average petroleum removal rate reaches 60% in the influence zone for 40 days continuous air sparging. The petroleum components in groundwater were analyzed by GC/MS (gas chromatogram-mass spectrograph) before and after experiments, respectively. The results show that the petroleum removal rate has relationship with the components and their properties. The petroleum components with higher volatility are easily removed by volatilization, but those with lower volatility are difficult to remove, so a tailing effect of lingering residual contaminant exists when the air sparging technology is adopted to treat groundwater contaminated by petroleum products.

  6. Intrinsic bioremediation of diesel-contaminated cold groundwater in bedrock

    International Nuclear Information System (INIS)

    Cross, K.M.; Biggar, K.W.; Guigard, S.E.

    2006-01-01

    Natural attenuation refers to the natural process by which contaminants in groundwater or soil are reduced through a combination of physico-chemical processes and biodegradation by indigenous organisms. The physico chemical processes include advection, dilution, dispersion, sorption, volatilization and abiotic transformation. This study evaluated the historical contaminant and geochemical evidence of natural attenuation at a well site where groundwater had been contaminated by a diesel fuel leak in 1982. In particular, evidence of intrinsic bioremediation was evaluated. Evidence of microbial activity was determined by most probably number (MPN) and commercial biological activity reaction tests. Groundwater samples from the site were incubated in a laboratory under aerobic and anaerobic conditions with electron acceptor and nutrient amendment to assess microbial activity. Mineralization of carbon 14-dodecane was measured to determine aerobic biodegradation rates. Anaerobic biodegradation rates were calculated from the depletion of total extractable hydrocarbon over 717 days. Nutrient addition increased the anaerobic first-order biodegradation rate from 0.0005 to 0.0016 per day. It was suggested controlled nutrient addition can improve the current slow rates of intrinsic bioremediation. 33 refs., 9 tabs., 5 figs

  7. Black Swans and the Effectiveness of Remediating Groundwater Contamination

    Science.gov (United States)

    Siegel, D. I.; Otz, M. H.; Otz, I.

    2013-12-01

    Black swans, outliers, dominate science far more than do predictable outcomes. Predictable success constitutes the Black Swan in groundwater remediation. Even the National Research Council concluded that remediating groundwater to drinking water standards has failed in typically complex hydrogeologic settings where heterogeneities and preferential flow paths deflect flow paths obliquely to hydraulic gradients. Natural systems, be they biological or physical, build upon a combination of large-scale regularity coupled to chaos at smaller scales. We show through a review of over 25 case studies that groundwater remediation efforts are best served by coupling parsimonious site characterization to natural and induced geochemical tracer tests to at least know where contamination advects with groundwater in the subsurface. In the majority of our case studies, actual flow paths diverge tens of degrees from anticipated flow paths because of unrecognized heterogeneities in the horizontal direction of transport, let alone the vertical direction. Consequently, regulatory agencies would better serve both the public and the environment by recognizing that long-term groundwater cleanup probably is futile in most hydrogeologic settings except to relaxed standards similar to brownfielding. A Black Swan

  8. Assessment of groundwater contamination risk using hazard quantification, a modified DRASTIC model and groundwater value, Beijing Plain, China.

    Science.gov (United States)

    Wang, Junjie; He, Jiangtao; Chen, Honghan

    2012-08-15

    Groundwater contamination risk assessment is an effective tool for groundwater management. Most existing risk assessment methods only consider the basic contamination process based upon evaluations of hazards and aquifer vulnerability. In view of groundwater exploitation potentiality, including the value of contamination-threatened groundwater could provide relatively objective and targeted results to aid in decision making. This study describes a groundwater contamination risk assessment method that integrates hazards, intrinsic vulnerability and groundwater value. The hazard harmfulness was evaluated by quantifying contaminant properties and infiltrating contaminant load, the intrinsic aquifer vulnerability was evaluated using a modified DRASTIC model and the groundwater value was evaluated based on groundwater quality and aquifer storage. Two groundwater contamination risk maps were produced by combining the above factors: a basic risk map and a value-weighted risk map. The basic risk map was produced by overlaying the hazard map and the intrinsic vulnerability map. The value-weighted risk map was produced by overlaying the basic risk map and the groundwater value map. Relevant validation was completed by contaminant distributions and site investigation. Using Beijing Plain, China, as an example, thematic maps of the three factors and the two risks were generated. The thematic maps suggested that landfills, gas stations and oil depots, and industrial areas were the most harmful potential contamination sources. The western and northern parts of the plain were the most vulnerable areas and had the highest groundwater value. Additionally, both the basic and value-weighted risk classes in the western and northern parts of the plain were the highest, indicating that these regions should deserve the priority of concern. Thematic maps should be updated regularly because of the dynamic characteristics of hazards. Subjectivity and validation means in assessing the

  9. Factors affecting gas migration and contaminant redistribution in heterogeneous porous media subject to electrical resistance heating.

    Science.gov (United States)

    Munholland, Jonah L; Mumford, Kevin G; Kueper, Bernard H

    2016-01-01

    A series of intermediate-scale laboratory experiments were completed in a two-dimensional flow cell to investigate gas production and migration during the application of electrical resistance heating (ERH) for the removal of dense non-aqueous phase liquids (DNAPLs). Experiments consisted of heating water in homogeneous silica sand and heating 270 mL of trichloroethene (TCE) and chloroform (CF) DNAPL pools in heterogeneous silica sands, both under flowing groundwater conditions. Spatial and temporal distributions of temperature were measured using thermocouples and observations of gas production and migration were collected using front-face image capture throughout the experiments. Post-treatment soil samples were collected and analyzed to assess DNAPL removal. Results of experiments performed in homogeneous sand subject to different groundwater flow rates showed that high groundwater velocities can limit subsurface heating rates. In the DNAPL pool experiments, temperatures increased to achieve DNAPL-water co-boiling, creating estimated gas volumes of 131 and 114 L that originated from the TCE and CF pools, respectively. Produced gas migrated vertically, entered a coarse sand lens and subsequently migrated laterally beneath an overlying capillary barrier to outside the heated treatment zone where 31-56% of the original DNAPL condensed back into a DNAPL phase. These findings demonstrate that layered heterogeneity can potentially facilitate the transport of contaminants outside the treatment zone by mobilization and condensation of gas phases during ERH applications. This underscores the need for vapor phase recovery and/or control mechanisms below the water table during application of ERH in heterogeneous porous media during the co-boiling stage, which occurs prior to reaching the boiling point of water. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Contaminant migration at two low-level radioactive waste sites in arid western United States - a review

    International Nuclear Information System (INIS)

    Wilshire, H.G.; Friedman, I.

    1999-01-01

    Contamination of the unsaturated zone and ground water at the Beatty, Nevada and Richland, Washington low-level radioactive waste sites shows that pathways exist for rapid lateral and vertical migration of contaminants through unconsolidated clastic sediments that comprise the 100 m-thick unsaturated zones of those arid disposal sites. Disposal of liquid wastes at the Beatty site until 1975 may have contributed to rapid migration of contaminants, but negligible amounts of liquid wastes reportedly were disposed at the Richland LLRW site and similar problems of contaminant migration exist. Pathways for vertical migration in the unsaturated zone include fractures and, at Richland, clastic dikes; lateral migration pathways likely are facies-controlled. Disturbance of the disposal sites contributed to increased infiltration of the unlined waste trenches after closure; simulations that used Beatty sample data show dramatic increases in recharge with disturbances necessary to develop the site. Because neither and arid climate nor presence of a thick unsaturated zone offer effective barriers to ground-water contamination, reliance on those factors at proposed sites such as Ward Valley, California and elsewhere is unwarranted. (orig.)

  11. Y-12 Groundwater Protection Program Extent Of The Primary Groundwater Contaminants At The Y-12 National Security Complex

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2013-12-01

    This report presents data summary tables and maps used to define and illustrate the approximate lateral extent of groundwater contamination at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee. The data tables and maps address the primary (i.e., most widespread and mobile) organic, inorganic, and radiological contaminants in the groundwater. The sampling locations, calculated contaminant concentrations, plume boundary values, and paired map format used to define, quantify, delineate, and illustrate the approximate extent of the primary organic, inorganic, and radiological contaminants in groundwater at Y-12 are described.

  12. Assessment of ground-water contamination near Lantana landfill, Southeast Florida

    Science.gov (United States)

    Russell, G.M.; Higer, A.L.

    1988-01-01

    The Lantana landfill located in Palm Beach County rises 40 to 50 feet above normal ground level and consists of about 250 acres of compacted garbage and trash, some below the water table. Surface-resistivity measurements and water-quality analyses indicate a contaminant plume along the eastern perimeter of the landfill that has migrated about 300 feet eastward toward an adjacent lake. Concentrations of chloride, ammonia, and nitrate were elevated within the plume. The surficial aquifer consists primarily of sand from 0 to about 68 feet, and sand interbedded with sandstone and limestone from 68 to 220 feet. A slight hydraulic gradient exists, indicating ground-water movement from the landfill toward a lake to the east. Analyses of geoelectric, lithologic, and water-quality data indicate that surface geophysical techniques were successful in determining the areal and vertical extent of leachate migration at this location.The Lantana landfill located in Palm Beach County rises 40 to 50 feet above normal ground level and consists of about 250 acres of compacted garbage and trash, some below the water table. Surface-resistivity measurements and water-quality analyses indicate a contaminant plume along the eastern perimeter of the landfill that has migrated about 300 feet eastward toward an adjacent lake. Concentrations of chloride, ammonia, and nitrate were elevated within the plume. The surficial aquifer consists primarily of sand from 0 to about 68 feet, and sand interbedded with sandstone and limestone from 68 to 220 feet. A slight hydraulic gradient exists, indicating ground-water movement from the landfill toward a lake to the east. Analyses of geoelectric, lithologic, and water-quality data indicate that surface geophysical techniques were successful in determining the areal and vertical extent of leachate migration at this location.

  13. Limitations of sorption isotherms on modeling groundwater contaminant transport

    International Nuclear Information System (INIS)

    Silva, Eduardo Figueira da

    2007-01-01

    Design and safety assessment of radioactive waste repositories, as well as remediation of radionuclide contaminated groundwater require the development of models capable of accurately predicting trace element fate and transport. Adsorption of trace radionuclides onto soils and groundwater is an important mechanism controlling near- and far- field transport. Although surface complexation models (SCMs) can better describe the adsorption mechanisms of most radionuclides onto mineral surfaces by directly accounting for variability of system properties and mineral surface properties, isotherms are still used to model contaminant transport in groundwater, despite the much higher system dependence. The present work investigates differences between transport model results based on these two approaches for adsorption modeling. A finite element transport model is used for the isotherm model, whereas the computer program PHREEQC is used for the SCM approach. Both models are calibrated for a batch experiment, and one-dimensional transport is simulated using the calibrated parameters. At the lower injected concentrations there are large discrepancies between SCM and isotherm transport predictions, with the SCM presenting much longer tails on the breakthrough curves. Isotherms may also provide non-conservative results for time to breakthrough and for maximum concentration in a contamination plume. Isotherm models are shown not to be robust enough to predict transport behavior of some trace elements, thus discouraging their use. The results also illustrate the promise of the SCM modeling approach in safety assessment and environmental remediation applications, also suggesting that independent batch sorption measurements can be used, within the framework of the SCM, to produce a more versatile and realistic groundwater transport model for radionuclides which is capable of accounting more accurately for temporal and spatial variations in geochemical conditions. (author)

  14. Fluoride contamination in groundwater resources of Alleppey, southern India

    Directory of Open Access Journals (Sweden)

    Dhanya Raj

    2017-01-01

    Full Text Available Alleppey is one of the thickly populated coastal towns of the Kerala state in southern India. Groundwater is the main source of drinking water for the 240,991 people living in this region. The groundwater is being extracted from a multi-layer aquifer system of unconsolidated to semi-consolidated sedimentary formations, which range in age from Recent to Tertiary. The public water distribution system uses dug and tube wells. Though there were reports on fluoride contamination, this study reports for the first time excess fluoride and excess salinity in the drinking water of the region. The quality parameters, like Electrical Conductivity (EC ranges from 266 to 3900 μs/cm, the fluoride content ranges from 0.68 to 2.88 mg/L, and the chloride ranges between the 5.7 to 1253 mg/L. The main water types are Na-HCO3, Na-CO3 and Na-Cl. The aqueous concentrations of F− and CO32− show positive correlation whereas F− and Ca2+ show negative correlation. The source of fluoride in the groundwater could be from dissolution of fluorapatite, which is a common mineral in the Tertiary sediments of the area. Long residence time, sediment–groundwater interaction and facies changes (Ca-HCO3 to Na-HCO3 during groundwater flow regime are the major factors responsible for the high fluoride content in the groundwater of the area. High strontium content and high EC in some of the wells indicate saline water intrusion that could be due to the excess pumping from the deeper aquifers of the area. The water quality index computation has revealed that 62% of groundwater belongs to poor quality and is not suitable for domestic purposes as per BIS and WHO standards. Since the groundwater is the only source of drinking water in the area, proper treatment strategies and regulating the groundwater extraction are required as the quality deterioration poses serious threat to human health.

  15. Bacterial contamination of groundwater in urban area of Karachi

    International Nuclear Information System (INIS)

    Zubair, A.; Rippey, B.

    1999-01-01

    Well-water samples (in=193) were collected from urban areas of five districts of Karachi during the period 1993 to 1995 to evaluate its bacteriological quality and their impact on city environment and morbidity patterns of inhabitants. Samples were analyzed by the standard method American Public Health Association. The bacteriological contamination level suggest that the groundwater of Chaahi is mainly affected by contamination of wastewater containing high levels of coliform and faecal coliform bacteria. This study points towards serious need to control the seepage from sewerage system and use of contaminated well-water should be discouraged to reduce the incidence of water-borne diseases in order to improve the quality of life and health. (author)

  16. Ground-water contamination at Wurtsmith Air Force Base, Michigan

    Science.gov (United States)

    Stark, J.R.; Cummings, T.R.; Twenter, F.R.

    1983-01-01

    A sand and gravel aquifer of glacial origin underlies Wurtsmith Air Force Base in northeastern lower Michigan. The aquifer overlies a thick clay layer at an average depth of 65 feet. The water table is about 10 feet below land surface in the western part of the Base and about 25 feet below land surface in the eastern part. A ground-water divide cuts diagonally across the Base from northwest to southeast. South of the divide, ground water flows to the Au Sable River; north of the divide, it flows to Van Etten Creek and Van Etten Lake. Mathematical models were used to aid in calculating rates of groundwater flow. Rates range from about 0.8 feet per day in the eastern part of the Base to about 0.3 feet per day in the western part. Models also were used as an aid in making decisions regarding purging of contaminated water from the aquifer. In 1977, trichloroethylene was detected in the Air Force Base water-supply system. It had leaked from a buried storage tank near Building 43 in the southeastern part of the Base and moved northeastward under the influence of the natural ground-water gradient and the pumping of Base water-supply wells. In the most highly contaminated part of the plume, concentrations are greater than 1,000 micrograms per liter. Current purge pumping is removing some of the trichloroethylene, and seems to have arrested its eastward movement. Pumping of additional purge wells could increase the rate of removal. Trichloroethylene has also been detected in ground water in the vicinity of the Base alert apron, where a plume from an unknown source extends northeastward off Base. A smaller, less well-defined area of contamination also occurs just north of the larger plume. Trichloroethylene, identified near the waste-treatment plant, seepage lagoons, and the northern landfill area, is related to activities and operations in these areas. Dichloroethylene and trichloroethylene occur in significant quantities westward of Building 43, upgradient from the major

  17. Review of risk from potential emerging contaminants in UK groundwater.

    Science.gov (United States)

    Stuart, Marianne; Lapworth, Dan; Crane, Emily; Hart, Alwyn

    2012-02-01

    This paper provides a review of the types of emerging organic groundwater contaminants (EGCs) which are beginning to be found in the UK. EGCs are compounds being found in groundwater that were previously not detectable or known to be significant and can come from agricultural, urban and rural point sources. EGCs include nanomaterials, pesticides, pharmaceuticals, industrial compounds, personal care products, fragrances, water treatment by-products, flame retardants and surfactants, as well as caffeine and nicotine. Many are relatively small polar molecules which may not be effectively removed by drinking water treatment. Data from the UK Environment Agency's groundwater screening programme for organic pollutants found within the 30 most frequently detected compounds a number of EGCs such as pesticide metabolites, caffeine and DEET. Specific determinands frequently detected include pesticides metabolites, pharmaceuticals including carbamazepine and triclosan, nicotine, food additives and alkyl phosphates. This paper discusses the routes by which these compounds enter groundwater, their toxicity and potential risks to drinking water and the environment. It identifies challenges that need to be met to minimise risk to drinking water and ecosystems. Copyright © 2012. Published by Elsevier B.V.

  18. Treatment of groundwater contaminated with low levels of military munitions

    International Nuclear Information System (INIS)

    Bricka, R.M.; Sharp, W.

    1993-01-01

    The site of interest is a military base that was established in the late 1800s. In its early history this facility was used as a powder depot to fill projectiles with miximite (a propellant). Since World War I, this facility was used to produce artillery ammunition, bombs, high explosives, pyrotechnics and other ordinances. Weapons production at this facility has ceased, but as a result of the past activities at this facility, contaminants are migrating into the groundwater. One source of drinking water for this installation is a screened well in a stratified-drift aquifer system at a depth of 75-85 feet below land surface. In the 1980s sampling of this well revealed low level contamination of trichloroethylene (TCE), RDX and HMX. TCE levels exceeded drinking water standards and an air stripping column was installed to remove the TCE. RDX and HMX, concentrations were below drinking water standards. Health Advisory (HA) levels for RDX and HMX were published by the U.S. Environmental Protection Agency (USEPA) in November 1988. The lifetime HA levels are 2 ppb and 400 ppb for RDX and HMX, respectively (McLellan et al. 1988a, and McLellan et al. 1988b). It is expected that continuous withdrawals from this well will increase RDX and HMX concentrations. In addition, it is believed that future USEPA regulations will adapt the HA as a drinking water standard. This study was initiated in an effort to have an appropriate cost effective technology ready to meet any such standard. RDX and HMX RDX and HMX are military explosives. RDX (Hexahydro-l,3,5-trinitro-l,3,5-triazine) is a code name for Research Department Explosive. This explosive is described as a white crystalline solid with about 1.3 times the explosive power of trinitrotoluene (TNT). RDX is classified as a EPA Group C compound: Possible Human Carcinogen (McLellan et. al. 1988a). HMX (Octahydro-1, 3, 5, 7- tetranitro-l, 3, 5, 7-tetrazocine) is a code name for High Melting Explosive. This explosive is described as a

  19. Modeling Groundwater-Surface Water Interaction and Contaminant Transport of Chlorinated Solvent Contaminated Site

    Science.gov (United States)

    Yimer Ebrahim, Girma; Jonoski, Andreja; van Griensven, Ann; Dujardin, Juliette; Baetelaan, Okke; Bronders, Jan

    2010-05-01

    Chlorinated-solvent form one of the largest groups of environmental chemicals. Their use and misuse in industry have lead to a large entry of these chemicals into the environment, resulting in widespread dissemination and oftentimes environmental contamination. Chlorinated solvent contamination of groundwater resources has been widely reported. For instance, there has been much interest in the assessment of these contaminant levels and their evolutions with time in the groundwater body below the Vilvoorde-Machelen industrial area (Belgium). The long industrial history of the area has lead to complex patterns of pollution from multiple sources and the site has been polluted to the extent that individual plumes are not definable any more. Understanding of groundwater/surface water interaction is a critical component for determining the fate of contaminant both in streams and ground water due to the fact that groundwater and surface water are in continuous dynamic interaction in the hydrologic cycle. The interaction has practical consequences in the quantity and quality of water in either system in the sense that depletion and/or contamination of one of the system will eventually affect the other one. The transition zone between a stream and its adjacent aquifer referred to as the hyporheic zone plays a critical role in governing contaminant exchange and transformation during water exchange between the two water bodies. The hyporheic zone of Zenne River ( the main receptor ) is further complicated due to the fact that the river banks are artificially trained with sheet piles along its reach extending some 12 m below the surface. This study demonstrates the use of MODFLOW, a widely used modular three-dimensional block-centred finite difference, saturated flow model for simulating the flow and direction of movement of groundwater through aquifer and stream-aquifer interaction and the use of transport model RT3D, a three-dimensional multi-species reactive transport model

  20. Neural Networks Simulation of the Transport of Contaminants in Groundwater

    Directory of Open Access Journals (Sweden)

    Enrico Zio

    2009-12-01

    Full Text Available The performance assessment of an engineered solution for the disposal of radioactive wastes is based on mathematical models of the disposal system response to predefined accidental scenarios, within a probabilistic approach to account for the involved uncertainties. As the most significant potential pathway for the return of radionuclides to the biosphere is groundwater flow, intensive computational efforts are devoted to simulating the behaviour of the groundwater system surrounding the waste deposit, for different values of its hydrogeological parameters and for different evolution scenarios. In this paper, multilayered neural networks are trained to simulate the transport of contaminants in monodimensional and bidimensional aquifers. The results obtained in two case studies indicate that the approximation errors are within the uncertainties which characterize the input data.

  1. Onsite disposal of radioactive waste: Estimating potential groundwater contamination

    International Nuclear Information System (INIS)

    Goode, D.J.; Neuder, S.M.; Pennifill, R.A.; Ginn, T.

    1986-11-01

    Volumes 1 and 2 of this report describe the NRC's methodology for assessing the potential public health and environmental impacts associated with onsite disposal of very low activity radioactive materials. This volume (Vol. 3) describes a general methodology for predicting potential groundwater contamination from onsite disposal. The methodology includes formulating a conceptual model, representing the conceptual model mathematically, estimating conservative parameters, and predicting receptor concentrations. Processes which must generally be considered in the methodology include infiltration, leaching of radionuclides from the waste, transport to the saturated zone, transport within the saturated zone, and withdrawal at a receptor location. A case study of shallow burial of iodine-125 illustrates application of the MOCMOD84 version of the US Geological Survey's 2-D solute transport model and a corresponding analytical solution. The appendices include a description and listing of MOCMOD84, descriptions of several analytical solution techniques, and a procedure for estimating conservative groundwater velocity values

  2. Arsenic contaminated groundwater and its treatment options in Bangladesh.

    Science.gov (United States)

    Jiang, Jia-Qian; Ashekuzzaman, S M; Jiang, Anlun; Sharifuzzaman, S M; Chowdhury, Sayedur Rahman

    2012-12-20

    Arsenic (As) causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues.

  3. Arsenic Contaminated Groundwater and Its Treatment Options in Bangladesh

    Directory of Open Access Journals (Sweden)

    Sayedur Rahman Chowdhury

    2012-12-01

    Full Text Available Arsenic (As causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues.

  4. Arsenic Contaminated Groundwater and Its Treatment Options in Bangladesh

    Science.gov (United States)

    Jiang, Jia-Qian; Ashekuzzaman, S. M.; Jiang, Anlun; Sharifuzzaman, S. M.; Chowdhury, Sayedur Rahman

    2012-01-01

    Arsenic (As) causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues. PMID:23343979

  5. DETERMINING EOSIN AS A GROUNDWATER MIGRATION TRACER BY CAPILLARY ELECTROPHORESIS/LASER-INDUCED FLUORESCENCE USING A MULTIWAVELENGTH LASER

    Science.gov (United States)

    Groundwater migration remains an important contributor in determining the distribution and fate of environmental pollutants originating from various waste sites or in understanding fate and transport .[ 1- 3] .Groundwater tracers are often used to determine the flow of groundwa...

  6. Phytoremediation of contaminated soils and groundwater: lessons from the field

    Energy Technology Data Exchange (ETDEWEB)

    Vangronsveld, J.; van der Lelie, D.; Herzig, R.; Weyens, N.; Boulet, J.; Adriaensen, K.; Ruttens, A.; Thewys, T.; Vassilev, A.; Meers, E.; Nehnevajova, E.; Mench, M.

    2009-11-01

    The use of plants and associated microorganisms to remove, contain, inactivate, or degrade harmful environmental contaminants (generally termed phytoremediation) and to revitalize contaminated sites is gaining more and more attention. In this review, prerequisites for a successful remediation will be discussed. The performance of phytoremediation as an environmental remediation technology indeed depends on several factors including the extent of soil contamination, the availability and accessibility of contaminants for rhizosphere microorganisms and uptake into roots (bioavailability), and the ability of the plant and its associated microorganisms to intercept, absorb, accumulate, and/or degrade the contaminants. The main aim is to provide an overview of existing field experience in Europe concerning the use of plants and their associated microorganisms whether or not combined with amendments for the revitalization or remediation of contaminated soils and undeep groundwater. Contaminations with trace elements (except radionuclides) and organics will be considered. Because remediation with transgenic organisms is largely untested in the field, this topic is not covered in this review. Brief attention will be paid to the economical aspects, use, and processing of the biomass. It is clear that in spite of a growing public and commercial interest and the success of several pilot studies and field scale applications more fundamental research still is needed to better exploit the metabolic diversity of the plants themselves, but also to better understand the complex interactions between contaminants, soil, plant roots, and microorganisms (bacteria and mycorrhiza) in the rhizosphere. Further, more data are still needed to quantify the underlying economics, as a support for public acceptance and last but not least to convince policy makers and stakeholders (who are not very familiar with such techniques).

  7. Using geographic distribution of well-screen depths and hydrogeologic conditions to identify areas of concern for contaminant migration through inactive supply wells

    Science.gov (United States)

    Gailey, Robert M.

    2018-02-01

    Contaminant migration through inactive supply wells can negatively affect groundwater quality and the combined effects from groups of such wells may cause greater impacts. Because the number of wells in many basins is often large and the geographic areas involved can be vast, approaches are needed to estimate potential impacts and focus limited resources for investigation and corrective measures on the most important areas. One possibility is to evaluate the geographic distribution of well-screen depths relative to hydrogeologic conditions and assess where contaminant migration through wells may be impacting groundwater quality. This approach is demonstrated for a geographically extensive area in the southern Central Valley of California, USA. The conditions that lead to wells acting as conduits for contaminant migration are evaluated and areas where the problem likely occurs are identified. Although only a small fraction of all wells appear to act as conduits, potential impacts may be significant considering needs to control nonpoint-source pollution and improve drinking water quality for rural residents. Addressing a limited number of areas where contaminant migration rates are expected to be high may cost-effectively accomplish the most beneficial groundwater quality protection and improvement. While this work focuses on a specific region, the results indicate that impacts from groups of wells may occur in other areas with similar conditions. Analyses similar to that demonstrated here may guide efficient investigation and corrective action in such areas with benefits occurring for groundwater quality. Potential benefits may justify expenditures to develop the necessary data for performing the analyses.

  8. Driving mechanism and sources of groundwater nitrate contamination in the rapidly urbanized region of south China

    Science.gov (United States)

    Zhang, Qianqian; Sun, Jichao; Liu, Jingtao; Huang, Guanxing; Lu, Chuan; Zhang, Yuxi

    2015-11-01

    Nitrate contamination of groundwater has become an environmental problem of widespread concern in China. We collected 899 groundwater samples from a rapidly urbanized area, in order to identify the main sources and driving mechanisms of groundwater nitrate contamination. The results showed that the land use has a significant effect on groundwater nitrate concentration (P population growth. This study revealed that domestic wastewater and industrial wastewater were the main sources of groundwater nitrate pollution. Therefore, the priority method for relieving groundwater nitrate contamination is to control the random discharge of domestic and industrial wastewater in regions undergoing rapid urbanization. Capsule abstract. The main driving mechanism of groundwater nitrate contamination was determined to be urban construction and the secondary and tertiary industrial development, and population growth.

  9. Degradation of sucralose in groundwater and implications for age dating contaminated groundwater.

    Science.gov (United States)

    Robertson, W D; Van Stempvoort, D R; Spoelstra, J; Brown, S J; Schiff, S L

    2016-01-01

    The artificial sweetener sucralose has been in use in Canada and the US since about 2000 and in the EU since 2003, and is now ubiquitous in sanitary wastewater in many parts of the world. It persists during sewage treatment and in surface water environments and as such, has been suggested as a powerful tracer of wastewater. In this study, longer-term persistence of sucralose was examined in groundwater by undertaking a series of three sampling snapshots of a well constrained wastewater plume in Canada (Long Point septic system) over a 6-year period from 2008 to 2014. A shrinking sucralose plume in 2014, compared to earlier sampling, during this period when sucralose use was likely increasing, provides clear evidence of degradation. However, depletion of sucralose from a mean of 40 μg/L in the proximal plume zone, occurred at a relatively slow rate over a period of several months to several years. Furthermore, examination of septic tank effluent and impacted groundwater at six other sites in Canada, revealed that sucralose was present in all samples of septic tank effluent (6-98 μg/L, n = 32) and in all groundwater samples (0.7-77 μg/L, n = 64). Even though sucralose degradation is noted in the Long Point plume, its ubiquitous presence in the groundwater plumes at all seven sites implies a relatively slow rate of decay in many groundwater septic plume environments. Thus, sucralose has the potential to be used as an indicator of 'recent' wastewater contamination. The presence of sucralose identifies groundwater that was recharged after 2000 in Canada and the US and after 2003 in the EU and many Asian countries. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Environmental restoration: Integrating hydraulic control of groundwater, innovative contaminant removal technologies and wetlands restoration--A case study at SRS

    International Nuclear Information System (INIS)

    Lewis, C.M.; Serkiz, S.M.; Adams, J.; Welty, M.

    1992-01-01

    The groundwater remediation program at the F and H Seepage Basins, Savannah River Sits (SRS) is a case study of the integration of various environmental restoration technologies at a single waste site. Hydraulic control measures are being designed to mitigate the discharge of groundwater plumes to surface water. One of the primary constituents of the plumes is tritium. An extraction and reinjection scenario is being designed to keep the tritium in circulation in the shallow groundwater, until it can naturally decay. This will be accomplished by extracting groundwater downgradient of the waste sites, treatment, and reinjection of the tritiated water into the water table upgradient of the basins. Innovative in-situ technologies, including electrolytic migration, are being field tested at the site to augment the pump-treat-reinject system. The in-situ technologies target removal of contaminants which are relatively immobile, yet represent long term risks to human health and the environment. Wetland restoration is an integral part of the F and H remediation program. Both in-situ treatment of the groundwater discharging the wetlands to adjust the pH, and replacement of water loss due to the groundwater extraction program ar being considered. Toxicity studies indicate that drought and the effects of low pH groundwater discharge have been factors in observed tree mortality in wetlands near the waste sites

  11. Enhanced biotransformation of TCE using plant terpenoids in contaminated groundwater.

    Science.gov (United States)

    Brown, J R-M; Thompson, I P; Paton, G I; Singer, A C

    2009-12-01

    To examine plant terpenoids as inducers of TCE (trichloroethylene) biotransformation by an indigenous microbial community originating from a plume of TCE-contaminated groundwater. One-litre microcosms of groundwater were spiked with 100 micromol 1(-1) of TCE and amended weekly for 16 weeks with 20 microl 1(-1) of the following plant monoterpenes: linalool, pulegone, R-(+) carvone, S-(-) carvone, farnesol, cumene. Yeast extract-amended and unamended control treatments were also prepared. The addition of R-carvone and S-carvone, linalool and cumene resulted in the biotransformation of upwards of 88% of the TCE, significantly more than the unamendment control (61%). The aforementioned group of terpenes also significantly (P TCE to be degraded than the remaining two terpenes (farnesol and pulegone), and the yeast extract treatment which biotransformed 74-75% of the TCE. The microbial community profile was monitored by denaturing gradient gel electrophoresis and demonstrated much greater similarities between the microbial communities in terpene-amended treatments than in the yeast extract or unamended controls. TCE biotransformation can be significantly enhanced through the addition of selected plant terpenoids. Plant terpenoid and nutrient supplementation to groundwater might provide an environmentally benign means of enhancing the rate of in situ TCE bioremediation.

  12. Risk assessment of groundwater environmental contamination: a case study of a karst site for the construction of a fossil power plant.

    Science.gov (United States)

    Liu, Fuming; Yi, Shuping; Ma, Haiyi; Huang, Junyi; Tang, Yukun; Qin, Jianbo; Zhou, Wan-Huan

    2017-12-20

    This paper presents a demonstration of an integrated risk assessment and site investigation for groundwater contamination through a case study, in which the geologic and hydrogeological feature of the site and the blueprint of the fossil power plant (FPP) were closely analyzed. Predictions for groundwater contamination in case of accidents were performed by groundwater modeling system (GMS) and modular three-dimensional multispecies transport model (MT3DMS). Results indicate that the studied site area presents a semi-isolated hydrogeological unit with multiplicity in stratum lithology, the main aquifers at the site are consisted of the filled karst development layer with a thickness between 6.0 and 40.0 m. The poor permeability of the vadose zone at the FPP significantly restricted the infiltration of contaminants through the vadose zone to the subsurface. The limited influence of rarely isotropic porous karstified carbonate rocks on the groundwater flow system premised the simulate scenarios of plume migration. Analysis of the present groundwater chemistry manifested that that the groundwater at the site and the local area are of the HCO 3 -Ca, HCO 3 , and SO 4 -Ca types. A few of the water samples were contaminated by coliform bacteria and ammonia nitrogen as a result of the local cultivation. Prediction results indicate that the impact of normal construction and operation processes on the groundwater environment is negligible. However, groundwater may be partly contaminated within a certain period in the area of leakage from the diesel tanks, the industrial wastewater pool, and the cooling tower water tank in case of accidents. On a positive note, none of the plumes would reach the local sensitive areas for groundwater using. Finally, an anti-seepage scheme and a monitoring program are proposed to safeguard the groundwater protection. The integrated method of the site investigation and risk assessment used in this case study can facilitate the protection of

  13. Distribution and migration mechanism of fluoride in groundwater in the Manas River Basin, Northwest China

    Science.gov (United States)

    Liu, Yalei; Jin, Menggui; Ma, Bin; Wang, Jianjun

    2018-04-01

    Elevated fluoride (F) concentration in groundwater is posing a public health risk in the Manas River Basin (MRB), Northwest China. Based on the characterization of regional groundwater flow, 90 groundwater samples from aquifers were analyzed, along with top-soil leachate and pore-water samples from aquitards. Stable oxygen (δ18O) and hydrogen isotopes, radiocarbon and hydrochemical analyses of the groundwater and pore-water samples were conducted to trace groundwater hydrological and hydrochemical processes and thereby understand the distribution and migration mechanism of F. The groundwater is recharged by meteoric precipitation through vapor condensation processes in the Tianshan Mountains. The F concentration in groundwater samples from this basin ranged from 0.11 to 48.15 mg/L (mean 2.56 mg/L). In 37 of the 90 groundwater samples, the F concentrations were above the safe level for drinking water. The F concentrations progressively increased with the residence time and well depths in the northwest of the alluvial-fluvial plain, where groundwater is overexploited for agricultural and domestic use. Positive correlations between F and sodium (Na)/calcium (Ca) indicate that the enrichment and migration of F are influenced by cation exchange processes under high-Na and alkaline pH conditions. The relationships between δ18O and F and chloride (Cl) concentrations were nonlinear due to leaching and mixing processes. This shows that vertical leaching by irrigation return flow and mixing with pore water are the dominant processes driving the migration of F in the groundwater flow system of MRB, in addition to geochemical processes.

  14. Screening of French groundwater for regulated and emerging contaminants.

    Science.gov (United States)

    Lopez, Benjamin; Ollivier, Patrick; Togola, Anne; Baran, Nicole; Ghestem, Jean-Philippe

    2015-06-15

    Nationwide screening of 411 emerging contaminants and other regulated compounds, including parent molecules and transformation products (TPs) having various uses and origins, was done at 494 groundwater sites throughout France during two sampling campaigns in the Spring and the Fall of 2011. One hundred and eighty substances (44% of the targeted compounds) were quantified in at least one sampling point. These included pharmaceuticals, industrial products, pesticides, their transformation products and other emerging compounds. Fifty-five compounds were quantified in more than 1% of the samples. Both regulated and emerging compounds were found. Among the unregulated compounds, acetaminophen, carbamazepine, perfluorinated compounds, dioxins/furans, tolyltriazole, bisphenol A, triazine transformation products, and caffeine were quantified in more than 10% of the samples analyzed. Concentrations exceeding the threshold of toxicological concern of 0.1 μg/L were found for tolyltriazole, bisphenol A and some of the triazine transformation products (DEDIA). These new results should help the water resource managers and environmental regulators develop sound policies regarding the occurrence and distribution of regulated and emerging contaminants in groundwater. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Studies Related to the Role of Colloids on the Transport of Some Radio Contaminants in Groundwater

    International Nuclear Information System (INIS)

    Mekhemar, H.S.A.

    2012-01-01

    The safety of a radioactive waste repository is related to its capacity to confine radioactivity and isolate it from biosphere. The most likely process that can lead to the release of radionuclides from a repository to the geosphere is transport by groundwater. The transport and distribution of radionuclides in groundwater or through geologic media depend on the radioactive source, the physicochemical forms of radionuclides and interactions of radionuclides with other components present in the groundwater. Colloids naturally exist in groundwater aquifers and can significantly impact contaminant migration rate. The presence of colloids affects contaminant transport in aquifers either by facilitation or retardation. The effect of the presence of colloid (Al 2 O 3 ) on the sorption characteristics of Co 2+ and Cs + , as two of the most important radionuclides commonly encountered in the Egyptian waste streams, onto yellow sand and clay taken from Inshas site was studied. Based on the obtained results, the maximum sorption capacity of Cs + and Co 2+ in presence of colloid was higher than sorption in absence of colloid but the sorption capacity of clay was found to be greater than that of yellow sand for both ions in absence and presence of colloid. Sorption capacity (q) increased by increasing initial metal ion concentration. The increasing temperature from 25 to 65 degree C leads to slight decrease in the sorption of Cs ions while lead to increase in sorption of Co ions. The kinetic data could be successfully interpreted by simplified second order kinetic expression. The rate constants and the theoretical equilibrium Sorption capacities were calculated for studied cases. It was demonstrated from column experiments that colloid presence influences radionuclides transport through fixed bed yellow sand column. Al 2 O 3 and Fe 2 O 3 colloids reduce the migration of Cs + and Co 2+ ions in all studied cases. From the results of desorption experiments it can be concluded

  16. REMEDIATION OF NITRATE-CONTAMINATED GROUNDWATER USING A BIOBARRIER

    International Nuclear Information System (INIS)

    STrietelmeir, B.

    2000-01-01

    A biobarrier system has been developed for use in remediating shallow alluvial groundwater. This barrier is made from highly porous materials that are relatively long-lasting, carbon-based (to supply a limiting nutrient in nitrate destruction, in most cases), and extremely inexpensive and easy to emplace. In a series of laboratory studies, we have determined the effectiveness of this barrier at destroying nitrate and perchlorate in groundwater from Mortandad Canyon at Los Alamos National Laboratory (LANL). This groundwater was obtained from a monitoring well, MCO-5, which is located in the flowpath of the discharge waters from the LANL Radioactive Liquid Waste Treatment Facility (RLWTF). Water with elevated nitrate levels has been discharged from this plant for many years, until recently when the nitrate levels have been brought under the discharge limits. However, the historical discharge has resulted in a nitrate plume in the alluvial groundwater in this canyon. The LANL Multi-Barrier project was initiated this past year to develop a system of barriers that would prevent the transport of radionuclides, metals, colloids and other contaminants, including nitrate and perchlorate, further down the canyon in order to protect populations down-gradient. The biobarrier. will be part of this Multi-Barrier system. We have demonstrated the destruction of nitrate at levels up to 6.5-9.7 mhl nitrate (400-600 mg/L), and that of perchlorate at levels of about 4.3 microM perchlorate (350 ppb). We have quantified the populations of microorganisms present in the biofilm that develops on the biobarrier. The results of this research will be discussed along with other potential applications of this system

  17. Comparative study of surrogate models for groundwater contamination source identification at DNAPL-contaminated sites

    Science.gov (United States)

    Hou, Zeyu; Lu, Wenxi

    2018-05-01

    Knowledge of groundwater contamination sources is critical for effectively protecting groundwater resources, estimating risks, mitigating disaster, and designing remediation strategies. Many methods for groundwater contamination source identification (GCSI) have been developed in recent years, including the simulation-optimization technique. This study proposes utilizing a support vector regression (SVR) model and a kernel extreme learning machine (KELM) model to enrich the content of the surrogate model. The surrogate model was itself key in replacing the simulation model, reducing the huge computational burden of iterations in the simulation-optimization technique to solve GCSI problems, especially in GCSI problems of aquifers contaminated by dense nonaqueous phase liquids (DNAPLs). A comparative study between the Kriging, SVR, and KELM models is reported. Additionally, there is analysis of the influence of parameter optimization and the structure of the training sample dataset on the approximation accuracy of the surrogate model. It was found that the KELM model was the most accurate surrogate model, and its performance was significantly improved after parameter optimization. The approximation accuracy of the surrogate model to the simulation model did not always improve with increasing numbers of training samples. Using the appropriate number of training samples was critical for improving the performance of the surrogate model and avoiding unnecessary computational workload. It was concluded that the KELM model developed in this work could reasonably predict system responses in given operation conditions. Replacing the simulation model with a KELM model considerably reduced the computational burden of the simulation-optimization process and also maintained high computation accuracy.

  18. Depth Stratification Leads to Distinct Zones of Manganese and Arsenic Contaminated Groundwater.

    Science.gov (United States)

    Ying, Samantha C; Schaefer, Michael V; Cock-Esteb, Alicea; Li, Jun; Fendorf, Scott

    2017-08-15

    Providing access to safe drinking water is a global challenge, for which groundwater is increasingly being used throughout the world. However, geogenic contaminants limit the suitability of groundwater for domestic purposes over large geographic areas across most continents. Geogenic contaminants in groundwater are often evaluated individually, but here we demonstrate the need to evaluate multiple contaminants to ensure that groundwater is safe for human consumption and agricultural usage. We compiled groundwater chemical data from three aquifer regions across the world that have been reported to have widespread As and Mn contamination including the Glacial Aquifer in the U.S., the Ganges-Brahmaputra-Mehta Basin within Bangladesh, and the Mekong Delta in Cambodia, along with newly sampled wells in the Yangtze River Basin of China. The proportion of contaminated wells increase by up to 40% in some cases when both As and Mn contaminants are considered. Wilcoxon rank-sum analysis indicates that Mn contamination consistently occurs at significantly shallower depths than As contaminated wells in all regions. Arsenic concentrations in groundwater are well predicted by redox indicators (Eh and dissolved oxygen) whereas Mn shows no significant relationship with either parameter. These findings illustrate that the number of safe wells may be drastically overestimated in some regions when Mn contamination is not taken into account and that depth may be used as a distinguishing variable in efforts to predict the presence of groundwater contaminants regionally.

  19. Geogenic Groundwater Contamination: A Case Study Of Canakkale - Western Turkey

    Science.gov (United States)

    Deniz, Ozan; Çalık, Ayten

    2016-04-01

    Study area is located NW of Turkey. Total area of the drainage basin is 465 square kilometers and mostly covered by volcanic rocks. Majority of these rocks have highly altered and lost their primary properties because of alteration processes. Especially argillic alteration is common. Tectonic movements and cooling fractures were created suitable circulation environment of groundwater in the rocks (secondary porosity). Alteration affects the composition of groundwater and some rock elements pass into groundwater during the movement of water in the cavities of rocks. High concentration of natural contaminants related to water-rock interaction in spring water has been studied in this research. Field measurements such as pH, electrical conductivity, temperature, oxidation-reduction potential and salinity carried out in 500 water points (spring, drilling, well and stream). 150 water samples taken from the water points and 50 rock samples taken from the source of springs has been investigated in point of major anion-cations, heavy metals and trace elements. Some components in the water such as pH (3.5-9.1), specific electrical conductivity (84-6400 microS/cm), aluminum (27-44902 ppb), iron (10-8048 ppb), manganese (0.13-8740 ppb), nickel (0.2-627 ppb), lead (0.1-42.5 ppb) and sulphate (10 to 1940 ppm) extremely high or low in the springs sourced from especially highly altered Miocene aged volcanic rocks. Some measured parameters highly above according to European Communities Drinking Water Regulations (2007) and TS266 (2015-Intended for Human Consumption Water Regulations of Turkey) drinking water standards. The most common element which is found in the groundwater is aluminum that is higher than to the drinking water standards (200 microg/L). The highest levels of the Al values measured in acidic waters with very low pH (3.4) emerging from altered volcanic rocks because of acid mine drainage in Obakoy district, north of the study area. The abundance of this element in

  20. Groundwater contamination from an inactive uranium mill tailings pile. 2. Application of a dynamic mixing model

    International Nuclear Information System (INIS)

    Narashimhan, T.N.; White, A.F.; Tokunaga, T.

    1986-01-01

    At Riverton, Wyoming, low pH process waters from an abandoned uranium mill tailings pile have been infiltrating into and contaminating the shallow water table aquifer. The contamination process has been governed by transient infiltration rates, saturated-unsaturated flow, as well as transient chemical reactions between the many chemical species present in the mixing waters and the sediments. In the first part of this two-part series the authors presented field data as well as an interpretation based on a static mixing models. As an upper bound, the authors estimated that 1.7% of the tailings water had mixed with the native groundwater. In the present work they present the results of numerical investigation of the dynamic mixing process. The model, DYNAMIX (DYNamic MIXing), couples a chemical speciation algorithm, PHREEQE, with a modified form of the transport algorithm, TRUMP, specifically designed to handle the simultaneous migration of several chemical constituents. The overall problem of simulating the evolution and migration of the contaminant plume was divided into three sub problems that were solved in sequential stages. These were the infiltration problem, the reactive mixing problem, and the plume-migration problem. The results of the application agree reasonably with the detailed field data. The methodology developed in the present study demonstrates the feasibility of analyzing the evolution of natural hydrogeochemical systems through a coupled analysis of transient fluid flow as well as chemical reactions. It seems worthwhile to devote further effort toward improving the physicochemical capabilities of the model as well as to enhance its computational efficiency

  1. Modelling assessment of regional groundwater contamination due to historic smelter emissions of heavy metals

    NARCIS (Netherlands)

    Grift, B. van der; Griffioen, J.

    2008-01-01

    Historic emissions from ore smelters typically cause regional soil contamination. We developed a modelling approach to assess the impact of such contamination on groundwater and surface water load, coupling unsaturated zone leaching modelling with 3D groundwater transport modelling. Both historic

  2. Arsenic Contamination of Groundwater in Nepal—An Overview

    Directory of Open Access Journals (Sweden)

    Sudhir Kumar Singh

    2010-12-01

    Full Text Available In Nepal, arsenic (As contamination is a major issue of current drinking water supply systems using groundwater and has recently been one of the major environmental health management issues especially in the plain region, i.e., in the Terai districts, where the population density is very high. The Terai inhabitants still use hand tube and dug wells (with hand held pumps that are bored at shallow to medium depth for their daily water requirements, including drinking water. The National Sanitation Steering Committee (NSSC, with the help of many other organizations, has completed arsenic blanket test in 25 districts of Nepal by analysing 737,009 groundwater samples. Several organizations, including academic institutions, made an effort to determine the levels of arsenic concentrations in groundwater and their consequences in Nepal. The results of the analyses on 25,058 samples tested in 20 districts, published in the status report of arsenic in Nepal (2003, demonstrated that the 23% of the samples were containing 10–50 µg/L of As, and the 8% of the samples were containing more than 50 µg/L of As. Recent status of over 737,009 samples tested, the 7.9% and 2.3% were contaminated by 10–50 µg/L and >50 µg/L, respectively of As. The present paper examines the various techniques available for the reduction of arsenic concentrations in Nepal in combination with the main results achieved, the socio-economic status and the strategies. This paper aims to comprehensively compile all existing data sets and analyze them scientifically, by trying to suggest a common sustainable approach for identifying the As contamination in the nation, that can be easily adopted by local communities for developing a sustainable society. The paper aims also to find probable solutions to quantify and mitigate As problem without any external support. The outcome of this paper will ultimately help to identify various ways for: identify risk areas; develop awareness; adopt

  3. Preliminary hydrogeologic assessment of a ground-water contamination area in Wolcott, Connecticut

    Science.gov (United States)

    Stone, J.R.; Casey, G.D.; Mondazzi, R.A.; Frick, T.W.

    1997-01-01

    Contamination of ground water by volatile organic compounds and inorganic constituents has been identified at a number of industrial sites in the Town of Wolcott, Connecticut. Contamination is also present at a municipal landfill in the City of Waterbury that is upgradient from the industrial sites in the local ground-water-flow system. The study area, which lies in the Western Highlands of Connecticut, is in the Mad River Valley, a tributary to the Naugatuck River. Geohydrologic units (aquifer materials) include unconsolidated glacial sediments (surficial materials) and fractured crystalline (metamorphic) bedrock. Surficial materials include glacial till, coarse-grained andfine-grained glacial stratified deposits, and postglacial floodplain alluvium and swamp deposits. The ground-water-flow system in the surficial aquifer is complex because the hydraulic properties of the surficial materials are highly variable. In the bedrock aquifer, ground water moves exclusively through fractures. Hydrologic characteristics of the crystalline bedrock-degree of confinement, hydraulic conductivity, storativity, and porosity-are poorly defined in the study area. Further study is needed to adequately assess ground-water flow and contaminant migration under current or past hydrologic conditions. All known water-supply wells in the study area obtain water from the bedrock aquifer. Twenty households in a hillside residential area on Tosun Road currently obtain drinking water from private wells tapping the bedrock aquifer. The extent of contamination in the bedrock aquifer and the potential for future contamination from known sources of contamination in the surficial aquifer is of concern to regulatory agencies. Previous investigations have identified ground-water contamination by volatile organic compounds at the Nutmeg Valley Road site area. Contamination has been associated with on-site disposal of heavy metals, chlorinated and non-chlorinated volatile organic compounds, and

  4. Emerging organic contaminants in groundwater : a review of sources, fate and occurrence

    OpenAIRE

    Lapworth, D.J.; Baran, N.; Stuart, M.E.; Ward, R.S.

    2012-01-01

    Emerging organic contaminants (EOCs) detected in groundwater may have adverse effects on human health and aquatic ecosystems. This paper reviews the existing occurrence data in groundwater for a range of EOCs including pharmaceutical, personal care, ‘life-style’ and selected industrial compounds. The main sources and pathways for organic EOCs in groundwater are reviewed, with occurrence data for EOCs in groundwater included from both targeted studies and broad reconnaissance surveys. Nanogram...

  5. Prevention and mitigation of groundwater contamination from radioactive releases

    International Nuclear Information System (INIS)

    1988-10-01

    This document gives basic information on potential pathways and mechanisms, by which radioactive materials from releases can reach man, and on modelling considerations to predict the behaviour of radioactive materials in the ground. The main objective is to present an overview of existing techniques for preventing the offsite releases of contaminants into the groundwater systems and techniques for mitigation of effects of such releases should they occur. The recommended techniques are fully applicable to any hazardous materials, such as organic liquids, and toxic materials or otherwise dangerous materials, the presence of which in the accessible biosphere can represent health risks as well as economic losses to the general public. 11 refs, 2 figs, 8 tabs

  6. Mathematical modeling of groundwater contamination with varying velocity field

    Directory of Open Access Journals (Sweden)

    Das Pintu

    2017-06-01

    Full Text Available In this study, analytical models for predicting groundwater contamination in isotropic and homogeneous porous formations are derived. The impact of dispersion and diffusion coefficients is included in the solution of the advection-dispersion equation (ADE, subjected to transient (time-dependent boundary conditions at the origin. A retardation factor and zero-order production terms are included in the ADE. Analytical solutions are obtained using the Laplace Integral Transform Technique (LITT and the concept of linear isotherm. For illustration, analytical solutions for linearly space- and time-dependent hydrodynamic dispersion coefficients along with molecular diffusion coefficients are presented. Analytical solutions are explored for the Peclet number. Numerical solutions are obtained by explicit finite difference methods and are compared with analytical solutions. Numerical results are analysed for different types of geological porous formations i.e., aquifer and aquitard. The accuracy of results is evaluated by the root mean square error (RMSE.

  7. Predicting geogenic arsenic contamination in shallow groundwater of south Louisiana, United States.

    Science.gov (United States)

    Yang, Ningfang; Winkel, Lenny H E; Johannesson, Karen H

    2014-05-20

    Groundwater contaminated with arsenic (As) threatens the health of more than 140 million people worldwide. Previous studies indicate that geology and sedimentary depositional environments are important factors controlling groundwater As contamination. The Mississippi River delta has broadly similar geology and sedimentary depositional environments to the large deltas in South and Southeast Asia, which are severely affected by geogenic As contamination and therefore may also be vulnerable to groundwater As contamination. In this study, logistic regression is used to develop a probability model based on surface hydrology, soil properties, geology, and sedimentary depositional environments. The model is calibrated using 3286 aggregated and binary-coded groundwater As concentration measurements from Bangladesh and verified using 78 As measurements from south Louisiana. The model's predictions are in good agreement with the known spatial distribution of groundwater As contamination of Bangladesh, and the predictions also indicate high risk of As contamination in shallow groundwater from Holocene sediments of south Louisiana. Furthermore, the model correctly predicted 79% of the existing shallow groundwater As measurements in the study region, indicating good performance of the model in predicting groundwater As contamination in shallow aquifers of south Louisiana.

  8. Modeling uranium transport in acidic contaminated groundwater with base addition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan [Institute of Tibetan Plateau Research, Chinese Academy of Sciences; Luo, Wensui [ORNL; Parker, Jack C. [University of Tennessee, Knoxville (UTK); Brooks, Scott C [ORNL; Watson, David B [ORNL; Jardine, Philip [University of Tennessee, Knoxville (UTK); Gu, Baohua [ORNL

    2011-01-01

    This study investigates reactive transport modeling in a column of uranium(VI)-contaminated sediments with base additions in the circulating influent. The groundwater and sediment exhibit oxic conditions with low pH, high concentrations of NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, U and various metal cations. Preliminary batch experiments indicate that additions of strong base induce rapid immobilization of U for this material. In the column experiment that is the focus of the present study, effluent groundwater was titrated with NaOH solution in an inflow reservoir before reinjection to gradually increase the solution pH in the column. An equilibrium hydrolysis, precipitation and ion exchange reaction model developed through simulation of the preliminary batch titration experiments predicted faster reduction of aqueous Al than observed in the column experiment. The model was therefore modified to consider reaction kinetics for the precipitation and dissolution processes which are the major mechanism for Al immobilization. The combined kinetic and equilibrium reaction model adequately described variations in pH, aqueous concentrations of metal cations (Al, Ca, Mg, Sr, Mn, Ni, Co), sulfate and U(VI). The experimental and modeling results indicate that U(VI) can be effectively sequestered with controlled base addition due to sorption by slowly precipitated Al with pH-dependent surface charge. The model may prove useful to predict field-scale U(VI) sequestration and remediation effectiveness.

  9. Modeling uranium transport in acidic contaminated groundwater with base addition

    International Nuclear Information System (INIS)

    Zhang Fan; Luo Wensui; Parker, Jack C.; Brooks, Scott C.; Watson, David B.; Jardine, Philip M.; Gu Baohua

    2011-01-01

    This study investigates reactive transport modeling in a column of uranium(VI)-contaminated sediments with base additions in the circulating influent. The groundwater and sediment exhibit oxic conditions with low pH, high concentrations of NO 3 - , SO 4 2- , U and various metal cations. Preliminary batch experiments indicate that additions of strong base induce rapid immobilization of U for this material. In the column experiment that is the focus of the present study, effluent groundwater was titrated with NaOH solution in an inflow reservoir before reinjection to gradually increase the solution pH in the column. An equilibrium hydrolysis, precipitation and ion exchange reaction model developed through simulation of the preliminary batch titration experiments predicted faster reduction of aqueous Al than observed in the column experiment. The model was therefore modified to consider reaction kinetics for the precipitation and dissolution processes which are the major mechanism for Al immobilization. The combined kinetic and equilibrium reaction model adequately described variations in pH, aqueous concentrations of metal cations (Al, Ca, Mg, Sr, Mn, Ni, Co), sulfate and U(VI). The experimental and modeling results indicate that U(VI) can be effectively sequestered with controlled base addition due to sorption by slowly precipitated Al with pH-dependent surface charge. The model may prove useful to predict field-scale U(VI) sequestration and remediation effectiveness.

  10. Modeling uranium transport in acidic contaminated groundwater with base addition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Fan, E-mail: zhangfan@itpcas.ac.cn [Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085 (China); Luo Wensui [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China); Parker, Jack C. [Institute for a Secure and Sustainable Environment, Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Brooks, Scott C.; Watson, David B. [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Jardine, Philip M. [Biosystems Engineering and Soil Science Department, University of Tennessee, Knoxville, TN 37996 (United States); Gu Baohua [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2011-06-15

    This study investigates reactive transport modeling in a column of uranium(VI)-contaminated sediments with base additions in the circulating influent. The groundwater and sediment exhibit oxic conditions with low pH, high concentrations of NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, U and various metal cations. Preliminary batch experiments indicate that additions of strong base induce rapid immobilization of U for this material. In the column experiment that is the focus of the present study, effluent groundwater was titrated with NaOH solution in an inflow reservoir before reinjection to gradually increase the solution pH in the column. An equilibrium hydrolysis, precipitation and ion exchange reaction model developed through simulation of the preliminary batch titration experiments predicted faster reduction of aqueous Al than observed in the column experiment. The model was therefore modified to consider reaction kinetics for the precipitation and dissolution processes which are the major mechanism for Al immobilization. The combined kinetic and equilibrium reaction model adequately described variations in pH, aqueous concentrations of metal cations (Al, Ca, Mg, Sr, Mn, Ni, Co), sulfate and U(VI). The experimental and modeling results indicate that U(VI) can be effectively sequestered with controlled base addition due to sorption by slowly precipitated Al with pH-dependent surface charge. The model may prove useful to predict field-scale U(VI) sequestration and remediation effectiveness.

  11. Groundwater arsenic contamination and its health effects in India

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Das, Bhaskar; Chatterjee, Amit; Das, Dipankar; Nayak, Biswajit; Pal, Arup; Chowdhury, Uttam Kumar; Ahmed, Sad; Biswas, Bhajan Kumar; Sengupta, Mrinal Kumar; Hossain, Md. Amir; Samanta, Gautam; Roy, M. M.; Dutta, Rathindra Nath; Saha, Khitish Chandra; Mukherjee, Subhas Chandra; Pati, Shyamapada; Kar, Probir Bijoy; Mukherjee, Adreesh; Kumar, Manoj

    2017-06-01

    During a 28-year field survey in India (1988-2016), groundwater arsenic contamination and its health effects were registered in the states of West Bengal, Jharkhand, Bihar and Uttar Pradesh in the Ganga River flood plain, and the states of Assam and Manipur in the flood plain of Brahamaputra and Imphal rivers. Groundwater of Rajnandgaon village in Chhattisgarh state, which is not in a flood plain, is also arsenic contaminated. More than 170,000 tubewell water samples from the affected states were analyzed and half of the samples had arsenic >10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.

  12. West Siberian basin hydrogeology - regional framework for contaminant migration from injected wastes

    International Nuclear Information System (INIS)

    Foley, M.G.

    1994-05-01

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in massive contamination of the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. Our long-term goal at Pacific Northwest Laboratory is to help determine future environmental and human impacts given the releases that have occurred to date and the current waste management practices. In FY 1993, our objectives were to (1) refine and implement the hydrogeologic conceptual models of the regional hydrogeology of western Siberia developed in FY 1992 and develop the detailed, spatially registered digital geologic and hydrologic databases to test them, (2) calibrate the computer implementation of the conceptual models developed in FY 1992, and (3) develop general geologic and hydrologic information and preliminary hydrogeologic conceptual models relevant to the more detailed models of contaminated site hydrogeology. Calibration studies of the regional hydrogeologic computer model suggest that most precipitation entering the ground-water system moves in the near-surface part of the system and discharges to surface waters relatively near its point of infiltration. This means that wastes discharged to the surface and near-surface may not be isolated as well as previously thought, since the wastes may be carried to the surface by gradually rising ground waters

  13. Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado

    International Nuclear Information System (INIS)

    1993-12-01

    This Baseline Risk Assessment of Groundwater Contamination at the Uranium Mill Tailings Site Near Gunnison, Colorado evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells. This risk assessment evaluates the most contaminated monitor wells at the processing site. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium

  14. Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    This Baseline Risk Assessment of Groundwater Contamination at the Uranium Mill Tailings Site Near Gunnison, Colorado evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells. This risk assessment evaluates the most contaminated monitor wells at the processing site. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium.

  15. Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado

    International Nuclear Information System (INIS)

    1994-04-01

    This report evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells to determine the potential for immediate human health and environmental impacts. This risk assessment evaluates the most contaminated groundwater that flows beneath the processing site towards the Gunnison River. The monitor wells that have consistently shown the highest concentration of most contaminants are used in this risk assessment. This risk assessment will be used in conjunction with additional activities and documents to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium

  16. Colloid migration in groundwaters: Geochemical interactions of radionuclides with natural colloids. Appendix III

    International Nuclear Information System (INIS)

    Wolf, M.; Geyer, S.; Fritz, P.; Klotz, D.; Lazik, D.

    1994-01-01

    The results obtained from the 152 Eu migration experiment in various columns packed with fine grained sand and equilibrated with a humic substance rich groundwater are: The retardation of mobile Eu-pseudocolloids (Eu-humate) is negligible, since the recovery is 152 Eu concentration is irreversible sorbed on the column, the degree of filtration expressed by the recovery is strongly dependant on the filtration velocity (flow rate): The recovery increases with increasing flow rates, indicating decreasing filtration, since the humic substances are negatively charged, the migration of the Eu pseudocolloids (humic colloids) is slightly accelerated relative to the migration of the 3 HHO tracer, due to anion repulsion. (orig.)

  17. 3D Geospatial Models for Visualization and Analysis of Groundwater Contamination at a Nuclear Materials Processing Facility

    Science.gov (United States)

    Stirewalt, G. L.; Shepherd, J. C.

    2003-12-01

    /liter) around the MPB and elevated nitrate (> 2000 milligrams/ liter) around storage ponds. Vertical connectivity was suggested between the TGWS and SGWS, while the DGWS appeared relatively isolated from the overlying aquifers. Lateral movement of uranium was also suggested over time. For example, lateral migration in the TGWS is suggested along a shallow depression in the bedrock surface trending south-southwest from the southwest corner of the MPB. Another pathway atop the buried bedrock surface, trending west-northwest from the MPB and partially reflected by current surface topography, suggested lateral migration of nitrate in the SGWS. Lateral movement of nitrate in the SGWS was also indicated north, south, and west of the largest storage pond. Definition of contaminant plume movement over time is particularly important for assessing direction and rate of migration and the potential need for preventive measures to control contamination of groundwater outside facility property lines. The 3D geospatial property models proved invaluable for visualizing and analyzing variations in subsurface uranium and nitrate contamination in space and time within and between the three aquifers at the site. The models were an exceptional visualization tool for illustrating extent, volume, and quantitative amounts of uranium and nitrate contamination in the subsurface to regulatory decision-makers in regard to site decommissioning issues, including remediation concerns, providing a perspective not possible to achieve with traditional 2D maps. The geohydrologic framework model provides a conceptual model for consideration in flow and transport analyses.

  18. Simulation of ground-water flow in the St. Peter aquifer in an area contaminated by coal-tar derivatives, St. Louis Park, Minnesota. Water Resources Investigation

    International Nuclear Information System (INIS)

    Lorenz, D.L.; Stark, J.R.

    1990-01-01

    A model constructed to simulate ground-water flow in part of the Prairie du Chien-Jordan and St. Peter aquifers, St. Louis Park, Minnesota, was used to test hypotheses about the movement of ground water contaminated with coal-tar derivatives and to simulate alternatives for reducing the downgradient movement of contamination in the St. Peter aquifer. The model, constructed for a previous study, was applied to simulate the effects of current ground-water withdrawals on the potentiometric surface of the St. Peter aquifer. Model simulations predict that the multiaquifer wells have the potential to limit downgradient migration of contaminants in the St. Peter aquifer caused by cones of depression created around the multiaquifer wells. Differences in vertical leakage to the St. Peter aquifer may exist in areas of bedrock valleys. Model simulations indicate that these differences are not likely to affect significantly the general patterns of ground-water flow

  19. Baseline risk assessment of groundwater contamination at the uranium mill tailings site near Shiprock, New Mexico

    International Nuclear Information System (INIS)

    1993-09-01

    This report evaluates potential impact to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1986 by the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This risk assessment is the first document specific to this site for the Groundwater Project. This risk assessment follows the approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the floodplain groundwater are arsenic, magnesium, manganese, nitrate, sodium, sulfate, and uranium. The complete list of contaminants associated with the terrace groundwater could not be determined due to the lack of the background groundwater quality data. However, uranium, nitrate, and sulfate are evaluated since these chemicals are clearly associated with uranium processing and are highly elevated compared to regional waters. It also could not be determined if the groundwater occurring in the terrace is a usable water resource, since it appears to have originated largely from past milling operations. The next step in the risk assessment is to estimate how much of these contaminants people would be exposed to if a drinking well were installed in the contaminated groundwater or if there were exposure to surface expressions of contaminated water. Potential exposures to surface water include incidental contact with contaminated water or sediments by children playing on the floodplain and consumption of meat and milk from domestic animals grazed and watered on the floodplain

  20. Increased concentrations of potassium in heartwood of trees in response to groundwater contamination

    Science.gov (United States)

    Vroblesky, Don A.; Yanosky, Thomas M.; Siegel, Frederic R.

    1992-03-01

    The wood of tuliptrees ( Liriodendron tulipifera L.) growing above groundwater contamination from a hazardous-waste landfill in Maryland contained elevated concentrations of potassium (K). The groundwater contamination also contained elevated concentrations of dissolved K, as well as arsenic (As), cadmium (Cd), chloride (Cl), iron (Fe), manganese (Mn), zinc (Zn), and organic solvents. The dissolved K is derived from disposed smoke munitions. The excess K in the tuliptrees is concentrated in the heartwood, the part of the xylem most depleted in K in trees growing outside of the contamination. These data show that the uptake and translocation of K by tuliptrees can be strongly influenced by the availability of K in groundwater contamination and suggest the utility of this species as an areal indicator of groundwater contamination.

  1. Increased concentrations of potassium in heartwood of trees in response to groundwater contamination

    Science.gov (United States)

    Vroblesky, D.A.; Yanosky, T.M.; Siegel, F.R.

    1992-01-01

    The wood of tuliptrees (Liriodendron tulipifera L.) growing above groundwater contamination from a hazardous-waste landfill in Maryland contained elevated concentrations of potassium (K). The groundwater contamination also contained elevated concentrations of dissolved K, as well as arsenic (As), cadmium (Cd), chloride (Cl), iron (Fe), manganese (Mn), zinc (Zn), and organic solvents. The dissolved K is derived from disposed smoke munitions. The excess K in the tuliptrees is concentrated in the heartwood, the part of the xylem most depleted in K in trees growing outside of the contamination. These data show that the uptake and translocation of K by tuliptrees can be strongly influenced by the availability of K in groundwater contamination and suggest the utility of this species as an areal indicator of groundwater contamination. ?? 1992 Springer-Verlag New York Inc.

  2. Chemistry of groundwater and the migration process of radionuclides

    International Nuclear Information System (INIS)

    Olteanu, Mirela; Popa, Aurelia; Crina, Bucur

    2001-01-01

    Establishing the criteria of selection of a host site for final repository of low and intermediate radioactive waste is based upon the study of two major components, the radioactivity diffusion in disposal site and the environmental impact. The hydrological characteristics of geological formation are the main factors that control radionuclides moving (migration), because, in general, the water is the natural way for dissolving and transport of these in environment. In interaction of the water with environment, the water is present like a dynamic and complex system, which contents dissolved or suspension of mineral and organic substances. Knowing the water-soil system interaction mechanism, the physical-chemical characteristics of each component in this system, the mobility in time of radionuclides, from the repository in environment can be estimated. In migration, the main problem is determination of transport rate of radionuclides in environment. (authors)

  3. 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.

  4. Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

    1984-04-01

    The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables.

  5. Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

    International Nuclear Information System (INIS)

    Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

    1984-04-01

    The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables

  6. Arsenic and fluoride contaminated groundwaters: A review of current technologies for contaminants removal.

    Science.gov (United States)

    Jadhav, Sachin V; Bringas, Eugenio; Yadav, Ganapati D; Rathod, Virendra K; Ortiz, Inmaculada; Marathe, Kumudini V

    2015-10-01

    Chronic contamination of groundwaters by both arsenic (As) and fluoride (F) is frequently observed around the world, which has severely affected millions of people. Fluoride and As are introduced into groundwaters by several sources such as water-rock interactions, anthropogenic activities, and groundwater recharge. Coexistence of these pollutants can have adverse effects due to synergistic and/or antagonistic mechanisms leading to uncertain and complicated health effects, including cancer. Many developing countries are beset with the problem of F and As laden waters, with no affordable technologies to provide clean water supply. The technologies available for the simultaneous removal are akin to chemical treatment, adsorption and membrane processes. However, the presence of competing ions such as phosphate, silicate, nitrate, chloride, carbonate, and sulfate affect the removal efficiency. Highly efficient, low-cost and sustainable technology which could be used by rural populations is of utmost importance for simultaneous removal of both pollutants. This can be realized by using readily available low cost materials coupled with proper disposal units. Synthesis of inexpensive and highly selective nanoadsorbents or nanofunctionalized membranes is required along with encapsulation units to isolate the toxicant loaded materials to avoid their re-entry in aquifers. A vast number of reviews have been published periodically on removal of As or F alone. However, there is a dearth of literature on the simultaneous removal of both. This review critically analyzes this important issue and considers strategies for their removal and safe disposal. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Groundwater recharge and agricultural contamination in alluvial fan of Eastern Kofu basin, JAPAN

    Science.gov (United States)

    Nakamura, T.

    2009-12-01

    Agriculture has significant effects on the rate and composition of groundwater recharge. The chemical loading into groundwater have been dominated by the constituents derived directly or indirectly from agricultural practices and additives. The contamination of groundwater with nitrate is a major public health and environmental concern around the world. The inorganic constituents like, K+, Ca2+, Mg2+, SO42-, Cl- and variety of other minor elements of groundwater are often used as agricultural additives; and the natural occurrence of these elements are dominated by the agricultural sources. A recent study has reported that Kofu basin groundwater aquifer is contaminated by nitrate from agricultural areas because of the fertilizer application for the orchard (Kazama and Yoneyama, 2002; Sakamoto et al., 1997, Nakamura et al., 2007). The water-oxygen and hydrogen stable isotope (δ18O and δD) and nitrate-nitrogen stable isotope (δ15N) of groundwater, river water and precipitation samples were investigated to identify the source of groundwater and nitrate nitrogen contamination in groundwater in the Fuefukigawa and Hikawa_Kanegawa alluvial fans in Kofu basin. The plot of δD versus δ18O values of groundwater, river water and precipitation samples suggest that the groundwater is a mixture of precipitation and river water. And nitrate-nitrogen isotope values have suggested the nitrate contamination of groundwater is from agricultural area. The study revealed positive correlation between groundwater δ18O values and NO3-, Cl-, SO42-, Ca2+, Mg2+ concentration, which shows the agricultural contamination is carried by the recharge of groundwater from precipitation in alluvial fan. Whereas, NO3-, Cl-, SO42-, Ca2+, Mg2+ are diluted by the river water recharges. This study showed the quality of groundwater is resulted from the mixing of water from the different source during the groundwater recharge in the study area. References Kazama F, Yoneyama M (2002) Nitrogen generation

  8. Anomalous migration of shallow groundwater and gases in the Beijing region and the 1976 Tangshan earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Shi, H. (Seismological Brigade of Beijing, China); Cai, Z.; Gao, M.

    1980-02-01

    The character and cause of blowing out of gases and emission of sound from dry wells and of water becoming muddy and changing of level in water wells of the Beijing region immediately before the 1976 Tangshan earthquake and its strong aftershocks are investigated. These phenomena, taken as possible precursors of the earthquakes as well as the motivating force, mechanism, geological background and material sources of the anomalous migration are discussed. Besides, the paper also deals with the relation between these anomalies and the Tangshan earthquake and the significance of the study of groundwater as far as earthquake prediction is concerned. No gaseous gushing from great depth in considerable quantities appeared so that migration should be regarded only as the migration of shallow groundwater and gases. This is referred to the consequence of the action on certain hydrogeological structures of an impulse-like extra tectonic stress field on the active faults in the Beijing region under a unified regional stress field. The present authors suppose that further studies of the anomalous migration of groundwater and gases possibly may be fruitful to earthquake prediction work.

  9. Anomalous migration of shallow groundwater and gases in the Beijing region and the 1976 Tangshan earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Shi, H.; Cai, Z.; Gao, M.

    1980-02-01

    The character and cause of blowing out of gases and emission of sound from dry wells and of water becoming muddy and changing of level in water wells of the Beijing region immediately before the 1976 Tangshan earthquake and its strong aftershocks are investigated. These phenomena, taken as possible precursors of the earthquakes as well as the motivating force, mechanism, geological background and material sources of the anomalous migration, are discussed. In addition, the paper also deals with the relation between these anomalies and the Tangshan earthquake and the significance of the study of groundwater as far as earthquake prediction is concerned. No gaseous gushing from great depth in considerable quantities appeared so that migration should be regarded only as the migration of shallow groundwater and gases. This is referred to as the consequence of the action on certain hydrogeological structures of an impulse-like extra tectonic stress field on the active faults in the Beijing region under a unified regional stress field. The present authors suppose that further studies of the anomalous migration of groundwater and gases possibly may be fruitful to earthquake prediction work.

  10. Tidal effects on groundwater contamination at Pekan, Pahang

    International Nuclear Information System (INIS)

    Nor Dalila Desa; Dominic, J.A.; Mohd Muzamil Mohd Hashim; Kamarudin Samuding; Mohd Faizun Khalid; Mod Omar Hassan; Kamaruzaman Mohamad

    2014-01-01

    The meeting of coastal ground water and the sea is a unique and dynamic hydro geologic boundary phenomenon that has fascinated groundwater engineers and scientists for the past century. The variation of seawater level resulting from tidal fluctuations is usually neglected in regional groundwater flow studies. In this study the effects of seawater tidal on groundwater are investigated using geophysical together with conventional method. Comparative result between these two methods shown how tidal fluctuations effects groundwater in study area. (author)

  11. Emerging organic contaminants in groundwater: A review of sources, fate and occurrence

    International Nuclear Information System (INIS)

    Lapworth, D.J.; Baran, N.; Stuart, M.E.; Ward, R.S.

    2012-01-01

    Emerging organic contaminants (EOCs) detected in groundwater may have adverse effects on human health and aquatic ecosystems. This paper reviews the existing occurrence data in groundwater for a range of EOCs including pharmaceutical, personal care, ‘life-style’ and selected industrial compounds. The main sources and pathways for organic EOCs in groundwater are reviewed, with occurrence data for EOCs in groundwater included from both targeted studies and broad reconnaissance surveys. Nanogram-microgram per litre concentrations are present in groundwater for a large range of EOCs as well as metabolites and transformation products and under certain conditions may pose a threat to freshwater bodies for decades due to relatively long groundwater residence times. In the coming decades, more of these EOCs are likely to have drinking water standards, environmental quality standards and/or groundwater threshold values defined, and therefore a better understanding of the spatial and temporal variation remains a priority. - Highlights: ► First review to focus on EOCs in groundwater. ► A large range (n > 180) of EOCs are detected in groundwater. ► Significant concentrations (10 2 –10 4 ng/L) for a range of EOCs, including endocrine disruptors. ► Groundwater EOC occurrence is poorly characterised compared to other freshwater resources. - A large range of emerging organic contaminants are now being detected in groundwater as a result of recent and historical anthropogenic activities.

  12. Hydrochemistry and Characteristics of Groundwater: Case Study Water Contamination at Citarum River Upstream

    Directory of Open Access Journals (Sweden)

    Mohamad Sapari Dwi Hadian

    2017-12-01

    Full Text Available Rancaekek and Sayang area, West Java, are the area where many industrial factories are located.Thus, the region becomes the targeted destination for industrial development.The  population in the area is rising due to the growth of industries causing the regional development becomes uncontrollable. In addition, the constant increment of waste and also poor-coordinated disposal systems may result in groundwater contamination in the areas. The rapid growth of the area increase the need for groundwater as well as the need for more research about contamination at Rancaekek and Sayang. The research aims to explore the spread of groundwater contamination in the area. The research method is carried out based on the analysis of Geological Mapping, Hydrogeological Mapping and chemical characteristics of the groundwater in the area. Chemical analyses of the groundwater were conducted through laboratory test of groundwater samples at specific spots of dug wells. The lab test results were further analyzed to determine the contamination zone. The findings reveal that the distribution of contamination in the area follow the shallow ground water flow patterns, the water contamination contains heavy metal and there is degradation of soil fertility. The findings suggest the stakeholders to delineate the contaminated area, and increase the dissemination of environmental awareness.

  13. Assessment of groundwater contamination by leachate near a ...

    African Journals Online (AJOL)

    The results show that the leachate from the landfill has a minimal impact on the groundwater resource and this can be attributed to the existing soil stratigraphy at the site consisting of clay which is deduced to have a significant influence on the natural attenuation of leachate into groundwater. Keywords: Groundwater ...

  14. Indicators to identify the source of pesticide contamination to groundwater

    DEFF Research Database (Denmark)

    Thorling, Lærke; Brüsch, Walter; Tuxen, Nina

    In Denmark groundwater is synonym with drinking water. The mainstream Danish political approach favors prevention and action at source over advanced treatments of polluted groundwater. The main pollutants are nitrate and pesticides. Pesticides in groundwater can originate from either diffuse or p...

  15. Carbonate and carbon isotopic evolution of groundwater contaminated by produced water brine with hydrocarbons

    International Nuclear Information System (INIS)

    Atekwana, Eliot A.; Seeger, Eric J.

    2015-01-01

    The major ionic and dissolved inorganic carbon (DIC) concentrations and the stable carbon isotope composition of DIC (δ"1"3C_D_I_C) were measured in a freshwater aquifer contaminated by produced water brine with petroleum hydrocarbons. Our aim was to determine the effects of produced water brine contamination on the carbonate evolution of groundwater. The groundwater was characterized by three distinct anion facies: HCO_3"−-rich, SO_4"2"−-rich and Cl"−-rich. The HCO_3"−-rich groundwater is undergoing closed system carbonate evolution from soil CO_2_(_g_) and weathering of aquifer carbonates. The SO_4"2"−-rich groundwater evolves from gypsum induced dedolomitization and pyrite oxidation. The Cl"−-rich groundwater is contaminated by produced water brine and undergoes common ion induced carbonate precipitation. The δ"1"3C_D_I_C of the HCO_3"−-rich groundwater was controlled by nearly equal contribution of carbon from soil CO_2_(_g_) and the aquifer carbonates, such that the δ"1"3C of carbon added to the groundwater was −11.6‰. In the SO_4"2"−-rich groundwater, gypsum induced dedolomitization increased the "1"3C such that the δ"1"3C of carbon added to the groundwater was −9.4‰. In the produced water brine contaminated Cl"−-rich groundwater, common ion induced precipitation of calcite depleted the "1"3C such that the δ"1"3C of carbon added to the groundwater was −12.7‰. The results of this study demonstrate that produced water brine contamination of fresh groundwater in carbonate aquifers alters the carbonate and carbon isotopic evolution. - Highlights: • We studied carbonate and δ"1"3C evolution in groundwater contaminated by produced water brine. • Multiple processes affect the carbonate and δ"1"3C evolution of the groundwater. • The processes are carbonate weathering, dedolomitization and common ion induce calcite precipitation. • The δ"1"3C added to DIC was −11.6‰ for weathering, −9.4‰ for dedolomitization

  16. Toxic fluoride and arsenic contaminated groundwater in the Lahore and Kasur districts, Punjab, Pakistan and possible contaminant sources

    International Nuclear Information System (INIS)

    Farooqi, Abida; Masuda, Harue; Firdous, Nousheen

    2007-01-01

    The present study is the first attempt to put forward possible sources of As, F - and SO 4 2- contaminated groundwater in the Kalalanwala area, Punjab, Pakistan. Five rainwater and 24 groundwater samples from three different depths were analyzed. Shallow groundwater from 24 to 27 m depth contained high F - (2.47-21.1 mg/L), while the groundwater samples from the deeper depth were free from fluoride contamination. All groundwater samples contained high As (32-1900 μg/L), in excess of WHO drinking water standards. The SO 4 2- ranges from 110 to 1550 mg/L. δ 34 S data indicate three sources for SO 4 2- air pollutants (5.5-5.7 per mille ), fertilizers (4.8 per mille ), and household waste (7.0 per mille ). Our important finding is the presence of SO 4 2- , As and F - in rainwater, indicating the contribution of these elements from air pollution. We propose that pollutants originate, in part, from coal combusted at brick factories and were mobilized promotionally by the alkaline nature of the local groundwater. - Simultaneous As and F - contamination of groundwater and possible pollutant sources are discussed

  17. Transuranic Contamination in Sediment and Groundwater at the U.S. DOE Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.

    2009-08-20

    A review of transuranic radionuclide contamination in sediments and groundwater at the DOE’s Hanford Site was conducted. The review focused primarily on plutonium-239/240 and americium-241; however, other transuranic nuclides were discussed as well, including neptunium-237, plutonium-238, and plutonium-241. The scope of the review included liquid process wastes intentionally disposed to constructed waste disposal facilities such as trenches and cribs, burial grounds, and unplanned releases to the ground surface. The review did not include liquid wastes disposed to tanks or solid wastes disposed to burial grounds. It is estimated that over 11,800 Ci of plutonium-239, 28,700 Ci of americium-241, and 55 Ci of neptunium-237 have been disposed as liquid waste to the near surface environment at the Hanford Site. Despite the very large quantities of transuranic contaminants disposed to the vadose zone at Hanford, only minuscule amounts have entered the groundwater. Currently, no wells onsite exceed the DOE derived concentration guide for plutonium-239/240 (30 pCi/L) or any other transuranic contaminant in filtered samples. The DOE derived concentration guide was exceeded by a small fraction in unfiltered samples from one well (299-E28-23) in recent years (35.4 and 40.4 pCi/L in FY 2006). The primary reason that disposal of these large quantities of transuranic radionuclides directly to the vadose zone at the Hanford Site has not resulted in widespread groundwater contamination is that under the typical oxidizing and neutral to slightly alkaline pH conditions of the Hanford vadose zone, transuranic radionuclides (plutonium and americium in particular) have a very low solubility and high affinity for surface adsorption to mineral surfaces common within the Hanford vadose zone. Other important factors are the fact that the vadose zone is typically very thick (hundreds of feet) and the net infiltration rate is very low due to the desert climate. In some cases where

  18. Baseline risk assessment for groundwater contamination at the uranium mill tailings site near Monument Valley, Arizona

    International Nuclear Information System (INIS)

    1993-09-01

    This baseline risk assessment evaluates potential impact to public health or the environment resulting from groundwater contamination at the former uranium mill processing site near Monument Valley, Arizona. The tailings and other contaminated material at this site are being relocated and stabilized in a disposal cell at Mexican Hat, Utah, through the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The tailings removal is planned for completion by spring 1994. After the tailings are removed, groundwater contamination at the site will continue to be evaluated. This risk assessment is the first document specific to this site for the Groundwater Project. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site

  19. PERMEABLE REACTIVE BARRIERS FOR IN-SITU TREATMENT OF ARSENIC-CONTAMINATED GROUNDWATER

    Science.gov (United States)

    Laboratory and field research has shown that permeable reactive barriers (PRBs) containing a variety of materials can treat arsenic (As) contaminated groundwater. Sites where these PRBs are located include a mine tailings facility, fertilizer and chemical manufacturing sites, a...

  20. Multi-Objective Optimization of an In situ Bioremediation Technology to Treat Perchlorate-Contaminated Groundwater

    Science.gov (United States)

    The presentation shows how a multi-objective optimization method is integrated into a transport simulator (MT3D) for estimating parameters and cost of in-situ bioremediation technology to treat perchlorate-contaminated groundwater.

  1. Prediction of contamination potential of groundwater arsenic in Cambodia, Laos, and Thailand using artificial neural network

    Science.gov (United States)

    The arsenic (As) contamination of groundwater has increasingly been recognized as a major global issue of concern. As groundwater resources are one of most important freshwater sources for water supplies in Southeast Asian countries, it is important to investigate the spatial distribution of As cont...

  2. Bioremediation Of Groundwater Contaminated Wtih Gasoline Hydrocarbons And Oxygenates Using A Membrane-Based Reactor

    Science.gov (United States)

    The objective of this study was to operate a novel, field-scale, aerobic bioreactor and assess its performance in the ex situ treatment of groundwater contaminated with gasoline from a leaking underground storage tank in Pascoag, RI. The groundwater contained elevated concentrat...

  3. Bioremediation of Uranium-Contaminated Groundwater using Engineered Injection and Extraction

    Science.gov (United States)

    Greene, J. A.; Neupauer, R.; Ye, M.; Kasprzyk, J. R.; Mays, D. C.; Curtis, G. P.

    2017-12-01

    During in-situ remediation of contaminated groundwater, a treatment chemical is injected into the contaminated groundwater to react with and degrade the contaminant, with reactions occurring where the treatment chemical contacts the contaminant. Traditional in-situ groundwater remediation relies on background groundwater flow for spreading of treatment chemicals into contaminant plumes. Engineered Injection and Extraction (EIE), in which time-varying induced flow fields are used to actively spread the treatment chemical into the contaminant plume, has been developed to increase contact between the contaminant and treatment chemical, thereby enhancing contaminant degradation. EIE has been investigated for contaminants that degrade through irreversible bimolecular reaction with a treatment chemical, but has not been investigated for a contaminant governed by reversible reactions. Uranium primarily occurs in its aqueous, mobile form, U(VI), in the environment but can be bioreduced to its sparingly soluble, immobile form, U(IV), by iron reducing bacteria stimulated by an acetate amendment. In this study, we investigate the ability of EIE to facilitate and sustain favorable conditions to immobilize uranium during remediation, and to prevent re-mobilization of uranium into the aqueous phase after active remediation has ended. Simulations in this investigation are conducted using a semi-synthetic model based on physical and chemical conditions at the Naturita Uranium Mill Tailings Remedial Action (UMTRA) site in southwestern Colorado and the Old Rifle UMTRA site in western Colorado. The EIE design is optimized for the synthetic model using the Borg multi-objective evolutionary algorithm.

  4. Simulation of Groundwater Flow and Migration of the Radioactive Cobalt-60 from LAMA Nuclear Facility-Iraq

    Directory of Open Access Journals (Sweden)

    Thair Sharif Khayyun

    2018-02-01

    Full Text Available This study provides a simulation of groundwater flow and advective-dispersive migration of radioactive Co-60 through an aquifer with three layers, which release or leak to groundwater from the Active Metallurgy Testing Laboratory (LAMA Nuclear Facility-Iraq due to the nuclear accident scenario. Processing Modflow for windows (PMWIN and Modular Three-Dimensional Multispecies Transport (MT3DMS Models were used for this purpose. The study area and the contaminated area were 12.7 km2 and 0.005625 km2, respectively. Water levels of the groundwater have been measured in six monitoring wells. The simulation time was assumed to have started in 2016. The PMWIN model simulated the flow for two scenarios of water level in Tigris River (average and minimum water levels. The MT3DMS model simulated 10 years of plume travel, beginning in 2016. The simulated Co-60 concentrations after five years of travel were 32.34 and 34.44 μg/m3 for the two scenarios. The maximum predicted Co-60 concentrations at the end of Year 10 were 34.86 and 37.31 μg/m3, respectively. The sensitivity analysis showed that the simulated hydraulic heads in the observation wells and the simulated plume of Co-60 were highly sensitive to changes in the effective porosity but less sensitive to changes in other parameters of the dispersion and chemical reaction processes. The time necessary to reach steady state condition was predicted to be approximately 16 years. The contaminated area was isolated by using remedial process which is represented by three fully penetrating pumping wells with a suitable flow rate (0.045 m3/s for controlling the movement of Co-60 pollutant.

  5. TECHNICAL BASIS FOR EVALUATING SURFACE BARRIERS TO PROTECT GROUNDWATER FROM DEEP VADOSE ZONE CONTAMINATION

    International Nuclear Information System (INIS)

    Fayer, J.M.; Freedman, V.L.; Ward, A.L.; Chronister, G.B.

    2010-01-01

    tasks to achieve those outcomes. Full understanding of contaminant behavior in the deep vadose zone is constrained by four key data gaps: limited access; limited data; limited time; and the lack of an accepted predictive capability for determining whether surface barriers can effectively isolate deep vadose zone contaminants. Activities designed to fill these data gaps need to have these outcomes: (1) common evaluation methodology that provides a clear, consistent, and defensible basis for evaluating groundwater impacts caused by placement of a surface barrier above deep vadose zone contamination; (2) deep vadose zone data that characterize the lithology, the spatial distribution of moisture and contaminants, the physical, chemical, and biological process that affect the mobility of each contaminant, and the impacts to the contaminants following placement of a surface barrier; (3) subsurface monitoring to provide subsurface characterization of initial conditions and changes that occur during and following remediation activities; and (4) field observations that span years to decades to validate the evaluation methodology. A set of six proposed tasks was identified to provide information needed to address the above outcomes. The proposed tasks are: (1) Evaluation Methodology - Develop common evaluation methodology that will provide a clear, consistent, and defensible basis for evaluating groundwater impacts caused by placement of a surface barrier above deep vadose zone contamination. (2) Case Studies - Conduct case studies to demonstrate the applicability ofthe common evaluation methodology and provide templates for subsequent use elsewhere. Three sites expected to have conditions that would yield valuable information and experience pertinent to deep vadose zone contamination were chosen to cover a range of conditions. The sites are BC Cribs and Trenches, U Plant Cribs, and the T Farm Interim Cover. (3) Subsurface Monitoring Technologies - Evaluate minimally invasive

  6. Inactive supply wells as conduits for flow and contaminant migration: conditions of occurrence and suggestions for management

    Science.gov (United States)

    Gailey, Robert M.

    2017-11-01

    Water supply wells can act as conduits for vertical flow and contaminant migration between water-bearing strata under common hydrogeologic and well construction conditions. While recognized by some for decades, there is little published data on the magnitude of flows and extent of resulting water quality impacts. Consequently, the issue may not be acknowledged widely enough and the need for better management persists. This is especially true for unconsolidated alluvial groundwater basins that are hydrologically stressed by agricultural activities. Theoretical and practical considerations indicate that significant water volumes can migrate vertically through wells. The flow is often downward, with shallow groundwater, usually poorer in quality, migrating through conduit wells to degrade deeper water quality. Field data from locations in California, USA, are presented in combination with modeling results to illustrate both the prevalence of conditions conducive to intraborehole flow and the resulting impacts to water quality. Suggestions for management of planned wells include better enforcement of current regulations and more detailed consideration of hydrogeologic conditions during design and installation. A potentially greater management challenge is presented by the large number of existing wells. Monitoring for evidence of conduit flow and solute transport in areas of high well density is recommended to identify wells that pose greater risks to water quality. Conduit wells that are discovered may be addressed through approaches that include structural modification and changes in operations.

  7. Colloid migration in groundwaters: Geochemical interactions of radionuclides with natural colloids. Final report

    International Nuclear Information System (INIS)

    Kim, J.J.; Longworth, G.; Hasler, S.E.; Gardiner, M.; Fritz, P.; Klotz, D.; Lazik, D.; Wolf, M.; Geyer, S.; Alexander, J.L.; Read, D.; Thomas, J.B.

    1994-08-01

    In this joint research programme the significance of groundwater colloids in far field radionuclide migration has been studied. The characterization, quantification and theoretical interpretation of colloid-borne transport phenomena for radionuclides were the main objectives of this research programme. Groundwaters, colloids and sediments were sampled from aquifer system overlying a saltdome in the Gorleben area in northern Germany and were characterized by various analytical methods (ICP-MS, ICP-AES, neutron activation analysis (NAA), DOC-Analyser, HPIC, potentiometric titration). Different natural isotopes ( 2 H, 3 H, 13 C, 14 C, 18 O, 34 S, U/Th decay series) were determined and their ratios were compared with one another in the order to ascertain the provenance of the groundwater colloids. The investigated groundwaters contain substantial amounts of colloids mainly composed of humic and fulvic acids loaded with various metal ions. The chemical interaction of radionuclide ions of various oxidation states (Am, Eu, for M(III), Th, Pu for M(IV), Np for M(V) and U for M(VI)) with groundwater colloids was investigated in order to elucidate the colloid facilitated migration behaviour of actinides in a given aquifer system. Transport process studies with generated pseudocolloids of radionuclides in various oxidation states were undertaken in scaled column experiments, pre-equilibrated with colloid rich Gorleben groundwater. A modelling programme was developed to predict chemical transport of radionuclides in the presence of humic colloids using a modified version of the CHEMTARD code. Modelling predictions have generated acceptable results for Eu, Am and U and poorer agreement between experimental and modelling results for Th and Np as a result of more limited data. (orig.)

  8. Colloid migration in groundwaters: Geochemical interactions of radionuclides with natural colloids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.J. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Radiochemie; Delakowitz, B. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Radiochemie; Zeh, P. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Radiochemie; Probst, T. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Radiochemie; Lin, X. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Radiochemie; Ehrlicher, U. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Radiochemie; Schauer, C. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Radiochemie; Ivanovich, M. [AEA Environment and Energy, Harwell (United Kingdom); Longworth, G. [AEA Environment and Energy, Harwell (United Kingdom); Hasler, S.E. [AEA Environment and Energy, Harwell (United Kingdom); Gardiner, M. [AEA Decommissioning and Radwaste, Harwell (United Kingdom); Fritz, P. [Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany); Klotz, D. [Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany); Lazik, D. [Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany); Wolf, M. [Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany); Geyer, S. [Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany); Alexander, J.L. [Atkins (W.S.) Engineering Sciences, Epsom (United Kingdom); Read, D. [Atkins (W.S.) Engineering Sciences, Epsom (United Kingdom); Thomas, J.B. [Atkins (W.S.) Engineering Sciences, Epsom (United Kingdom)

    1994-08-01

    In this joint research programme the significance of groundwater colloids in far field radionuclide migration has been studied. The characterization, quantification and theoretical interpretation of colloid-borne transport phenomena for radionuclides were the main objectives of this research programme. Groundwaters, colloids and sediments were sampled from aquifer system overlying a saltdome in the Gorleben area in northern Germany and were characterized by various analytical methods (ICP-MS, ICP-AES, neutron activation analysis (NAA), DOC-Analyser, HPIC, potentiometric titration). Different natural isotopes ({sup 2}H, {sup 3}H, {sup 13}C, {sup 14}C, {sup 18}O, {sup 34}S, U/Th decay series) were determined and their ratios were compared with one another in the order to ascertain the provenance of the groundwater colloids. The investigated groundwaters contain substantial amounts of colloids mainly composed of humic and fulvic acids loaded with various metal ions. The chemical interaction of radionuclide ions of various oxidation states (Am, Eu, for M(III), Th, Pu for M(IV), Np for M(V) and U for M(VI)) with groundwater colloids was investigated in order to elucidate the colloid facilitated migration behaviour of actinides in a given aquifer system. Transport process studies with generated pseudocolloids of radionuclides in various oxidation states were undertaken in scaled column experiments, pre-equilibrated with colloid rich Gorleben groundwater. A modelling programme was developed to predict chemical transport of radionuclides in the presence of humic colloids using a modified version of the CHEMTARD code. Modelling predictions have generated acceptable results for Eu, Am and U and poorer agreement between experimental and modelling results for Th and Np as a result of more limited data. (orig.)

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

    International Nuclear Information System (INIS)

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

    1992-11-01

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

  10. Case studies illustrating in-situ remediation methods for soil and groundwater contaminated with petrochemicals

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Robert A.; Lance, P.E.; Downs, A.; Kier, Brian P. [EMCON Northwest Inc., Portland, OR (United States)

    1993-12-31

    Four case studies of successful in-situ remediation are summarized illustrating cost-effective methods to remediate soil and groundwater contaminated with volatile and non-volatile petrochemicals. Each site is in a different geologic environment with varying soil types and with and without groundwater impact. The methods described include vadose zone vapor extraction, high-vacuum vapor extraction combined with groundwater tab.le depression, air sparging with groundwater recovery and vapor extraction, and bio remediation of saturated zone soils using inorganic nutrient and oxygen addition

  11. Case studies illustrating in-situ remediation methods for soil and groundwater contaminated with petrochemicals

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Robert A; Lance, P E; Downs, A; Kier, Brian P [EMCON Northwest Inc., Portland, OR (United States)

    1994-12-31

    Four case studies of successful in-situ remediation are summarized illustrating cost-effective methods to remediate soil and groundwater contaminated with volatile and non-volatile petrochemicals. Each site is in a different geologic environment with varying soil types and with and without groundwater impact. The methods described include vadose zone vapor extraction, high-vacuum vapor extraction combined with groundwater tab.le depression, air sparging with groundwater recovery and vapor extraction, and bio remediation of saturated zone soils using inorganic nutrient and oxygen addition

  12. Arsenic contamination of groundwater: Mitigation strategies and policies

    Science.gov (United States)

    Alaerts, Guy J.; Khouri, Nadim

    Contamination of groundwater by arsenic from natural geochemical sources is at present a most serious challenge in the planning of large-scale use of groundwater for drinking and other purposes. Recent improvements in detection limits of analytical instruments are allowing the correlation of health impacts such as cancer with large concentrations of arsenic in groundwater. However, there are at present no known large-scale technological solutions for the millions of people-mostly rural-who are potentially affected in developing countries. An overall framework of combating natural resource degradation is combined with case studies from Chile, Mexico, Bangladesh and elsewhere to arrive at a set of strategic recommendations for the global, national and local dimensions of the arsenic ``crisis''. The main recommendations include: the need for flexibility in the elaboration of any arsenic mitigation strategy, the improvement and large-scale use of low-cost and participatory groundwater quality testing techniques, the need to maintain consistent use of key lessons learned worldwide in water supply and sanitation and to integrate arsenic as just one other factor in providing a sustainable water supply, and the following of distinct but communicable tracks between arsenic-related developments and enhanced, long-term, sustainable water supplies. La contamination des eaux souterraines par l'arsenic provenant de sources naturelles est actuellement un sujet des plus graves dans l'organisation d'un recours à grande échelle des eaux souterraines pour la boisson et d'autres usages. De récentes améliorations dans les limites de détection des équipements analytiques permettent de corréler les effets sur la santé tels que le cancer à de fortes concentrations en arsenic dans les eaux souterraines. Toutefois, il n'existe pas actuellement de solutions technologiques à grande échelle connues pour des millions de personnes, surtout en zones rurales, qui sont potentiellement

  13. A Sustainability Assessment Methodology for Prioritizing the Technologies of Groundwater Contamination Remediation

    DEFF Research Database (Denmark)

    An, Da; Xi, Beidou; Wang, Yue

    2016-01-01

    More and more groundwater has 23 been polluted recently, and technologies for groundwater contamination remediation are of vital importance; however, it is usually difficult for the users to select the most suitable technology among multiple alternatives. In order to address this, this study aims...... at developing a sustainability assessment framework for prioritizing the technologies for groundwater contamination remediation by combining the concept of sustainability and multi-criteria decision making (MCDM) method. A criterion system which consists of six criteria in three aspects has been proposed...... for sustainability assessment of technologies for groundwater contamination remediation, and a novel MCDM method by combining the logarithmic fuzzy preference programming based fuzzy analytic hierarchy process and the improved ELECTRE method has been developed for prioritizing the alternatives. In order...

  14. An initial research on solute migration model coupled with adsorption of surface complexation in groundwater

    International Nuclear Information System (INIS)

    Qian Tianwei; Chen Fanrong

    2003-01-01

    The influence of solution chemical action in groundwater on solute migration has attracted increasing public attention, especially adsorption action occurring on surface of solid phase and liquid phase, which has play a great role in solute migration. There are various interpretations on adsorption mechanism, in which surface complexion is one of successful hypothesis. This paper first establishes a geochemical model based on surface complexion and then coupled it with traditional advection-dispersion model to constitute a solute migration model, which can deal with surface complexion action. The simulated results fit very well with those obtained by the precursors, as compared with a published famous example, which indicates that the model set up by this paper is successful. (authors)

  15. Fluoride contamination of groundwater and health implications in ...

    African Journals Online (AJOL)

    The arid climate of the region, the granitic rocks and the low freshwater exchange due to periodical drought conditions are responsible for the higher incidence of fluorides in the groundwater resource. The people dependent on groundwater resources in the area are prone to dental fluorosis and mild skeletal fluorosis.

  16. Use of Additives in Bioremediation of Contaminated Groundwater and Soil

    Science.gov (United States)

    This chapter reviews application of additives used in bioremediation of chlorinated solvents and fuels for groundwater and soil remediation. Soluble carbon substrates are applicable to most site conditions except aquifers with very high or very low groundwater flow. Slow-release ...

  17. Treatability study on the Bear Creek Valley characterization area at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Phase II work plan for S-3 site contaminated groundwater interception--in-field media evaluation and groundwater capture methods

    International Nuclear Information System (INIS)

    1996-12-01

    A treatability study is being conducted to support implementation:of early actions at the S-3 Site in the Bear Creek Valley (BCV) Characterization Area (CA). The objectives of the early actions Will be (1) to reduce concentrations of uranium and nitrate in Bear Creek and (2) to reduce contaminants of concern in North Tributary (NT)-1 and NT-2. The BCV CA is located within the US DOE's Oak Ridge Reservation in Tennessee. Hazardous and radioactive materials from the Y-12 Plant operations were, disposed of at various sites within BCV. Groundwater and surface water in the BCV CA have been contaminated. The remedial investigation (RI) for the BCV CA identified that the greatest mass flux of contaminants from the various sources migrates via groundwater at the source and discharges to surface water in Bear Creek and its tributaries. In the RI, the combined discharge from the S-3 Site and the Boneyard/Burnyard (BYBY) was identified as accounting for 75% of the cancer risk and more than 80% of the chemical toxicity to Potential downgradient human receptors. In addition, the S-3 Site has caused degradation of surface water quality in upper Bear Creek and two of its tributaries. The BCV CA treatability study focuses on capture and treatment of shallow groundwater before it discharges to tributary waters. The objectives Of treatment of this groundwater are (1) to reduce the concentrations of uranium and nitrate in NT-1 and Bear Creek such that the concentrations of these chemicals in surface water and groundwater are reduced to acceptable levels, (2) to reduce the concentrations of nitrate and metals, and reduce the overall concentration of total dissolved solids; and (3) to hydraulically contain the plume of contaminated, groundwater that is moving in bedrock in the Nolichucky Shale such that the rate of contaminant discharge will be reduced in the long term. The objective of Phase II is to produce conceptual designs for treatment system configurations

  18. PHYTOREMEDIATION: USING PLANTS TO CLEAN UP CONTAMINATED SOIL, GROUNDWATER, AND WASTEWATER

    Science.gov (United States)

    Phytoremediation is an emerging cleanup technology for contaminated soils, groundwater, and wastewater that is both low-tech and low-cost. The cleanup technology is defined as the use of green plants to remove, contain, or render harmless such environmental contaminants as heavy ...

  19. Chlorobenzene removal efficiencies and removal processes in a pilot-scale constructed wetland treating contaminated groundwater

    DEFF Research Database (Denmark)

    Braeckevelt, M.; Reiche, N.; Trapp, Stefan

    2011-01-01

    Low-chlorinated benzenes (CBs) are widespread groundwater contaminants and often threaten to contaminate surface waters. Constructed wetlands (CWs) in river floodplains are a promising technology for protecting sensitive surface water bodies from the impact of CBs. The efficiency and seasonal var...

  20. Guidelines for active spreading during in situ chemical oxidation to remediate contaminated groundwater

    Science.gov (United States)

    The effectiveness of in situ chemical oxidation to remediate contaminated aquifers depends on the extent and duration of contact between the injected treatment chemical and the groundwater contaminant (the reactants). Techniques that inject and extract in the aquifer to ‘ac...

  1. Flourescence Humic Substances in Arsenic Contaminated Groundwater of Bangladesh

    Directory of Open Access Journals (Sweden)

    SHAFI M. TAREQ

    2012-06-01

    Full Text Available In the past, only arsenic (As concentrations in groundwater of Bangladesh were considered as having direct effects on the epidemical degrees of different types of diseases including arsenicosis, but the results of the present investigation indicated that fluorescence humic substance (HS is also an important component of dissolved organic matter in groundwater of Bangladesh. Therefore, it is suspected that both fluorescent HS and As in groundwater may have effects on the biological toxicity. The evidence of presence of high fluorescent HS and As in groundwater of Faridpur supports the above synergistic effect. The spatial distribution of fluorescence HS and As in groundwater of Faridpur indicated that the variations may be related to local hydrogeological conditions.

  2. Behavioral response to contamination risk information in a spatially explicit groundwater environment: Experimental evidence

    Science.gov (United States)

    Li, Jingyuan; Michael, Holly A.; Duke, Joshua M.; Messer, Kent D.; Suter, Jordan F.

    2014-08-01

    This paper assesses the effectiveness of aquifer monitoring information in achieving more sustainable use of a groundwater resource in the absence of management policy. Groundwater user behavior in the face of an irreversible contamination threat is studied by applying methods of experimental economics to scenarios that combine a physics-based, spatially explicit, numerical groundwater model with different representations of information about an aquifer and its risk of contamination. The results suggest that the threat of catastrophic contamination affects pumping decisions: pumping is significantly reduced in experiments where contamination is possible compared to those where pumping cost is the only factor discouraging groundwater use. The level of information about the state of the aquifer also affects extraction behavior. Pumping rates differ when information that synthesizes data on aquifer conditions (a "risk gauge") is provided, despite invariant underlying economic incentives, and this result does not depend on whether the risk information is location-specific or from a whole aquifer perspective. Interestingly, users increase pumping when the risk gauge signals good aquifer status compared to a no-gauge treatment. When the gauge suggests impending contamination, however, pumping declines significantly, resulting in a lower probability of contamination. The study suggests that providing relatively simple aquifer condition guidance derived from monitoring data can lead to more sustainable use of groundwater resources.

  3. Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

    Energy Technology Data Exchange (ETDEWEB)

    K. Pohlmann; G. Pohll; J. Chapman; A. Hassan; R. Carroll; C. Shirley

    2004-03-01

    The purpose of this work is to characterize groundwater flow and contaminant transport at the Shoal underground nuclear test through numerical modeling using site-specific hydrologic data. The ultimate objective is the development of a contaminant boundary, a model-predicted perimeter defining the extent of radionuclide-contaminated groundwater from the underground test throughout 1,000 years at a prescribed level of confidence. This boundary will be developed using the numerical models described here, after they are approved for that purpose by DOE and NDEP.

  4. Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

    International Nuclear Information System (INIS)

    K. Pohlmann; G. Pohll; J. Chapman; A. Hassan; R. Carroll; C. Shirley

    2004-01-01

    The purpose of this work is to characterize groundwater flow and contaminant transport at the Shoal underground nuclear test through numerical modeling using site-specific hydrologic data. The ultimate objective is the development of a contaminant boundary, a model-predicted perimeter defining the extent of radionuclide-contaminated groundwater from the underground test throughout 1,000 years at a prescribed level of confidence. This boundary will be developed using the numerical models described here, after they are approved for that purpose by DOE and NDEP

  5. Development of a biotreatment system for the remediation of groundwater contaminated with hydrocarbons and trichloroethylene

    International Nuclear Information System (INIS)

    Folsom, B.R.; Kurisko, P.R.; Ensley, B.D.

    1992-01-01

    Inadvertent release of fuels and solvents into soil has resulted in groundwater contamination across the United States. This paper reports on the development of biologically based systems for treating mixtures of chemical contaminants which often requires knowledge of both degradative pathways and interactions between individual chemicals. These issues may necessitate the use of specialized microorganisms and/or treatment systems designed to overcome these limitations. One strategy for the treatment of chemical mixtures which cannot be source separated, such as contaminated groundwater, is a modular system to sequentially biodegrade groups of compatible chemicals. A two-stage bioreactor system was constructed for the treatment of groundwater contaminated with benzene and TCE. This treatment system is undergoing development for a field pilot demonstration. Successful implementation of this system should result in significant cost and time savings compared to competitive technologies

  6. Screening Assessment of Radionuclide Migration in Groundwater from the “Dneprovskoe” Tailings Impoundment (Dneprodzerzhynsk City) and Evaluation of Remedial Options

    Energy Technology Data Exchange (ETDEWEB)

    Skalskyi, O.; Bugai, D. [Institute of Geological Sciences, National Academy of Sciences of Ukraine (Ukraine); Ryazantsev, V. [State Nuclear Regularity Committee of Ukraine, Kiev (Ukraine)

    2014-05-15

    The paper presents results of mathematical modeling of the hydrogeological conditions at the “Dneprovskoe” (“D”) tailings impoundment –object of the former industrial association of “Pridneprovsky Chemical Plant”, which contains uranium ore processing wastes. This radioactively polluted site is located in a densely populated region (at the outskirts of Dneprodzerginsk City) near the major watercourse of the Ukraine — Dnieper River.The mathematical modeling utilized Visual Modflow (for groundwater flow) and Ecolego (Facilia AB, Sweden) radioecology modeling software (for radionuclide transport).Modeling results indicate the possibility of essential radioactive contamination in future of the phreatic aquifer in alluvial deposits between the “D” tailings and the Dnieper River (mainly due to migration of uranium). Therefore long-term management strategies should preclude water usage from the aquifer in the zone of the in-fluence of the “D” tailings. Filtration discharge of uranium to the Dnepr River does not represent a significant risk due to large dilution by surface waters. The important modeling conclusion is that besides the uranium ore processing wastes inside the tailings, the major source of radionuclide migration to groundwater is represented by contaminated geological deposits below the tailings. This last source was formed due to leakage of wastewaters during the operational period of the “D” tailings (1954–1968). Therefore an exemption and re-disposal of wastes from the “D” tailings to a more safe storage location (proposed by some remedial plans) will not provide significant benefit from the viewpoint of minimizing of radionuclide transport to the groundwater and Dnieper River (especially in short-and medium-term perspective). The rational remedial strategy for the “D” tailings is conservation of tailing wastes in-situ by means of specially designed “zero flux” soil screen, which would minimize infiltration of

  7. Global aquifers dominated by fossil groundwaters but wells vulnerable to modern contamination

    Science.gov (United States)

    Jasechko, Scott; Perrone, Debra; Befus, Kevin M.; Bayani Cardenas, M.; Ferguson, Grant; Gleeson, Tom; Luijendijk, Elco; McDonnell, Jeffrey J.; Taylor, Richard G.; Wada, Yoshihide; Kirchner, James W.

    2017-06-01

    The vulnerability of groundwater to contamination is closely related to its age. Groundwaters that infiltrated prior to the Holocene have been documented in many aquifers and are widely assumed to be unaffected by modern contamination. However, the global prevalence of these `fossil' groundwaters and their vulnerability to modern-era pollutants remain unclear. Here we analyse groundwater carbon isotope data (12C, 13C, 14C) from 6,455 wells around the globe. We show that fossil groundwaters comprise a large share (42-85%) of total aquifer storage in the upper 1 km of the crust, and the majority of waters pumped from wells deeper than 250 m. However, half of the wells in our study that are dominated by fossil groundwater also contain detectable levels of tritium, indicating the presence of much younger, decadal-age waters and suggesting that contemporary contaminants may be able to reach deep wells that tap fossil aquifers. We conclude that water quality risk should be considered along with sustainable use when managing fossil groundwater resources.

  8. Petrol contaminated groundwater treatment with air-stripper in Balassagyarmat, Hungary

    International Nuclear Information System (INIS)

    Szabo, Peter; Bernath, Balazs

    2005-01-01

    Hydrocarbon contaminated groundwater is a common environmental problem in Hungary. Leakage of underground storage tanks, pipe break or illegal tapping as well as lorry accidents can be mentioned as main reasons. MEGATERRA Ltd. elaborated, adopted and tested several groundwater clean-up methods. These methods are based on detailed survey and investigation, sampling and analysis, delineation of contaminated groundwater, risk assessment, establishment of monitoring wells, pumping tests and remediation action plan. One of these methods was implemented by MEGATERRA Ltd. in Balassagyarmat, Hungary. Contamination source was a 10 m 3 vol. simple wall underground fuel-storage tank, which had been emptied. When the remediation started in April 1998, the petrol had already been accumulated on the ground water table forming a 5-7 m wide and 10-15 m long plume being expanded to SSE-NNW direction. The area of the dissolved hydrocarbon contaminated groundwater-body was 1 000 m 2 and its concentration reached up to 30-40 mg/l TPH. The free-phase hydrocarbon layer was 10 cm thick. For the remediation of contaminated groundwater MEGATERRA Ltd. applied pump and treat method, namely groundwater pumping using extraction well, skimming of free-phase hydrocarbon, stripping of the contaminated ground water in air-stripper tower and draining of the treated groundwater into a drainage ditch. In the centre of the plume we established an extraction well with 300 mm diameter in a 500 mm borehole. Peristaltic skimmer pump was used inside the extraction well to remove the free phase petrol from the ground water surface.Because of the intense volatility of the pollutant we applied aeration (stripping) technology. The extracted contaminated groundwater was cleaned in air-stripper equipment being able to eliminate efficiently the volatile pollutants from the water. The aeration tower is a compact cylindrical shaped column with 650 mm in diameter. Its height depends on the pollutant's type The

  9. Determination of timescales of nitrate contamination by groundwater age models in a complex aquifer system

    Science.gov (United States)

    Koh, E. H.; Lee, E.; Kaown, D.; Lee, K. K.; Green, C. T.

    2017-12-01

    Timing and magnitudes of nitrate contamination are determined by various factors like contaminant loading, recharge characteristics and geologic system. Information of an elapsed time since recharged water traveling to a certain outlet location, which is defined as groundwater age, can provide indirect interpretation related to the hydrologic characteristics of the aquifer system. There are three major methods (apparent ages, lumped parameter model, and numerical model) to date groundwater ages, which differently characterize groundwater mixing resulted by various groundwater flow pathways in a heterogeneous aquifer system. Therefore, in this study, we compared the three age models in a complex aquifer system by using observed age tracer data and reconstructed history of nitrate contamination by long-term source loading. The 3H-3He and CFC-12 apparent ages, which did not consider the groundwater mixing, estimated the most delayed response time and a highest period of the nitrate loading had not reached yet. However, the lumped parameter model could generate more recent loading response than the apparent ages and the peak loading period influenced the water quality. The numerical model could delineate various groundwater mixing components and its different impacts on nitrate dynamics in the complex aquifer system. The different age estimation methods lead to variations in the estimated contaminant loading history, in which the discrepancy in the age estimation was dominantly observed in the complex aquifer system.

  10. Effect of land use and urbanization on hydrochemistry and contamination of groundwater from Taejon area, Korea

    Science.gov (United States)

    Jeong, Chan Ho

    2001-11-01

    Taejon Metropolitan City located in the central part of South Korea has grown and urbanized rapidly. The city depends heavily on groundwater as a water resource. Because of ubiquitous pollution sources, the quality and contamination have become important issues for the urban groundwater supply. This study has investigated the chemical characteristics and the contamination of groundwater in relation to land use. An attempt was made to distinguish anthrophogenic inputs from the influence of natural chemical weathering on the chemical composition of groundwater at Taejon. Groundwater samples collected at 170 locations in the Taejon area show very variable chemical composition of groundwater, e.g. electrical conductance ranges from 65 to 1,290 μS/cm. Most groundwater is weakly acidic and the groundwater chemistry is more influenced by land use and urbanization than by aquifer rock type. Most groundwater from green areas and new town residential districts has low electrical conductance, and is of Ca-HCO3 type, whereas the chemical composition of groundwater from the old downtown and industrial district is shifted towards a Ca-Cl (NO3+SO4) type with high electrical conductance. A number of groundwater samples in the urbanized area are contaminated by high nitrate and chlorine, and exhibit high hardness. The EpCO2, that is the CO2 content of a water sample relative to pure water, was computed to obtain more insight into the origin of CO2 and bicarbonate in the groundwater. The CO2 concentration of groundwater in the urbanized area shows a rough positive relationship with the concentration of major inorganic components. The sources of nitrate, chlorine and excess CO2 in the groundwater are likely to be municipal wastes of unlined landfill sites, leaky latrines and sewage lines. Chemical data of commercial mineral water from other Jurassic granite areas were compared to the chemical composition of the groundwater in the Taejon area. Factor analysis of the chemical data

  11. Leaching and soil/groundwater transport of contaminants from coal combustion residues

    International Nuclear Information System (INIS)

    Hjelmar, O.; Hansen, E.A.; Larsen, F.; Thomassen, H.

    1992-01-01

    In this project the results of accelerated laboratory leaching tests on coal fly ash and flue gas desulfurization (FGD) products from the spray dryer absorption process (SDA) were evaluated by comparison to the results of large scale lysimeter leaching tests on the same residues. The mobility of chromium and molybdenum - two of the kev contaminants of coal combustion residue leachates - in various typical soil types was investigated by batch and column methods in the laboratory. Some of the results were confirmed by field observations at an old coal fly ash disposal site and by a lysimeter attenuation test with coal fly ash leachate on a clayed till. A large number of groundwater transport models and geochemical models were reviewed, and two of the models (Gove-Stollenwerk and CHMTRNS) were modified and adjusted and used to simulate column attenuation tests performed in the laboratory. One of the models (Grove-Stollenwerk) was used to illustrate a recommended method of environmental impact assessment, using lysimeter leaching data and laboratory column attenuation data to describe the emission and migration of Mo from a coal fly ash disposal site

  12. Characterization of redox conditions in groundwater contaminant plumes

    Science.gov (United States)

    Christensen, Thomas H.; Bjerg, Poul L.; Banwart, Steven A.; Jakobsen, Rasmus; Heron, Gorm; Albrechtsen, Hans-Jørgen

    2000-10-01

    Evaluation of redox conditions in groundwater pollution plumes is often a prerequisite for understanding the behaviour of the pollutants in the plume and for selecting remediation approaches. Measuring of redox conditions in pollution plumes is, however, a fairly recent issue and yet relative few cases have been reported. No standardised or generally accepted approach exists. Slow electrode kinetics and the common lack of internal equilibrium of redox processes in pollution plumes make, with a few exceptions, direct electrochemical measurement and rigorous interpretation of redox potentials dubious, if not erroneous. Several other approaches have been used in addressing redox conditions in pollution plumes: redox-sensitive compounds in groundwater samples, hydrogen concentrations in groundwater, concentrations of volatile fatty acids in groundwater, sediment characteristics and microbial tools, such as MPN counts, PLFA biomarkers and redox bioassays. This paper reviews the principles behind the different approaches, summarizes methods used and evaluates the approaches based on the experience from the reported applications.

  13. Analyzing tree cores to detect petroleum hydrocarbon-contaminated groundwater at a former landfill site in the community of Happy Valley-Goose Bay, eastern Canadian subarctic.

    Science.gov (United States)

    Fonkwe, Merline L D; Trapp, Stefan

    2016-08-01

    This research examines the feasibility of analyzing tree cores to detect benzene, toluene, ethylbenzene, and m, p, o-xylene (BTEX) compounds and methyl tertiary-butyl ether (MTBE) in groundwater in eastern Canada subarctic environments, using a former landfill site in the remote community of Happy Valley-Goose Bay, Labrador. Petroleum hydrocarbon contamination at the landfill site is the result of environmentally unsound pre-1990s disposal of households and industrial solid wastes. Tree cores were taken from trembling aspen, black spruce, and white birch and analyzed by headspace-gas chromatography-mass spectrometry. BTEX compounds were detected in tree cores, corroborating known groundwater contamination. A zone of anomalously high concentrations of total BTEX constituents was identified and recommended for monitoring by groundwater wells. Tree cores collected outside the landfill site at a local control area suggest the migration of contaminants off-site. Tree species exhibit different concentrations of BTEX constituents, indicating selective uptake and accumulation. Toluene in wood exhibited the highest concentrations, which may also be due to endogenous production. Meanwhile, MTBE was not found in the tree cores and is considered to be absent in the groundwater. The results demonstrate that tree-core analysis can be useful for detecting anomalous concentrations of petroleum hydrocarbons, such as BTEX compounds, in subarctic sites with shallow unconfined aquifers and permeable soils. This method can therefore aid in the proper management of contamination during landfill operations and after site closures.

  14. Hydrodynamic analysis application of contaminated groundwater remediation to oil hydrocarbons

    OpenAIRE

    Pajić Predrag R.; Čalenić Aleksandar I.; Polomčić Dušan M.; Bajić Dragoljub I.

    2017-01-01

    In this paper, the application of the hydrodynamic analysis in the selected ‘pumping and treatment’ remediation method of groundwater hydrocarbon pollution in the case of the Pancevo oil refinery is examined. The applied hydrodynamic analysis represents a regular and necessary approach in modern hydrogeology. Previous chemical analysis of soil and groundwater samples at observation objects revealed their pollution by oil products. New researches included the constraction of 12 piezometric bor...

  15. Assessment of natural attenuation of ground-water contamination at sites FT03, LF13, and WP14/LF15, Dover Air Force Base, Delaware

    Science.gov (United States)

    Barbaro, Jeffrey R.

    2002-01-01

    Water-quality, aquifer-sediment, and hydro-logic data were used to assess the effectiveness of natural attenuation of ground-water contamination at Fire Training Area Three, the Rubble Area Landfill, the Liquid Waste Disposal Landfill, and the Receiver Station Landfill in the East Management Unit of Dover Air Force Base, Delaware. These sites, which are contaminated with chlorinated solvents and fuel hydrocarbons, are under-going long-term monitoring to determine if natural attenuation continues to sufficiently reduce contaminant concentrations to meet regulatory requirements. This report is the first assessment of the effectiveness of natural attenuation at these sites since long-term monitoring began in 1999, and follows a preliminary investigation done in 1995?96. This assessment was done by the U.S. Geological Survey in cooperation with the U.S. Air Force.Since 1995?96, additional information has been collected and used in the current assessment. The conclusions in this report are based primarily on ground-water samples collected from January through March 2000. Previous analytical results from selected wells, available geologic and geo-physical well logs, and newly acquired information such as sediment organic-carbon measurements, hydraulic-conductivity measurements determined from slug tests on wells in the natural attenuation study area, and water-level measurements from surficial-aquifer wells also were used in this assessment. This information was used to: (1) calculate retardation factors and estimate contaminant migration velocities, (2) improve estimates of ground-water flow directions and inferred contaminant migration pathways, (3) better define the areal extent of contamination and the proximity of contaminants to discharge areas and the Base boundary, (4) develop a better under-standing of the vertical variability of contaminant concentrations and redox conditions, (5) evaluate the effects of temporal changes on concentrations in the plumes and

  16. Arsenic levels in the groundwater of Korea and the urinary excretion among contaminated area.

    Science.gov (United States)

    Park, Jung-Duck; Choi, Seong-Jin; Choi, Byung-Sun; Lee, Choong-Ryeol; Kim, Heon; Kim, Yong-Dae; Park, Kyung-Soo; Lee, Young-Jo; Kang, Seojin; Lim, Kyung-Min; Chung, Jin-Ho

    2016-09-01

    Drinking water is a main source of human exposure to arsenic. Hence, the determination of arsenic in groundwater is essential to assess its impact on public health. Here, we report arsenic levels in the groundwater of 722 sites covering all six major provinces of Korea. Water was sampled in two occasions (summer, 722 sites and winter, 636 sites) and the arsenic levels were measured with highly sensitive inductively coupled plasma-mass spectrometry method (limit of detection, 0.1 μg/l) to encompass the current drinking water standard (arsenic in groundwater ranged from 0.1 to 48.4 μg/l. A 88.0-89.0% of sites were 10 μg/l. Notably, urinary arsenic excretion of people around these regions was markedly higher compared with non-contaminated areas (arsenic-contaminated groundwater may contribute to its systemic exposure.

  17. Use of LCA as decision support for the selection of remedial strategies for remediation of contaminated soil and groundwater

    DEFF Research Database (Denmark)

    Lemming, Gitte; Hauschild, Michael Zwicky; Bjerg, Poul Løgstrup

    2009-01-01

    , there is a trade-off between obtaining local beneficial effects from the remediation and generating environmental impacts on the regional and global scale due to the remedial actions. Therefore there is a need for including the impact of soil contaminants that will potentially leach to the groundwater, e......Groundwater is the dominant source of drinking water in Denmark and the general policy is to maintain the groundwater as a clean source of drinking water. The risk of groundwater contamination is therefore often the prime reason for remediating a contaminated site. Chlorinated solvents are among...... the contaminants most frequently found to be threatening the groundwater quality in Denmark and worldwide. Life cycle assessment has recently been applied as part of decision support for contaminated site management and subsurface remediation techniques. Impacts in the groundwater compartment have only gained...

  18. Implications of matrix diffusion on 1,4-dioxane persistence at contaminated groundwater sites.

    Science.gov (United States)

    Adamson, David T; de Blanc, Phillip C; Farhat, Shahla K; Newell, Charles J

    2016-08-15

    Management of groundwater sites impacted by 1,4-dioxane can be challenging due to its migration potential and perceived recalcitrance. This study examined the extent to which 1,4-dioxane's persistence was subject to diffusion of mass into and out of lower-permeability zones relative to co-released chlorinated solvents. Two different release scenarios were evaluated within a two-layer aquifer system using an analytical modeling approach. The first scenario simulated a 1,4-dioxane and 1,1,1-TCA source zone where spent solvent was released. The period when 1,4-dioxane was actively loading the low-permeability layer within the source zone was estimated to be high effective solubility. While this was approximately an order-of-magnitude shorter than the loading period for 1,1,1-TCA, the mass of 1,4-dioxane stored within the low-permeability zone at the end of the simulation period (26kg) was larger than that predicted for 1,1,1-TCA (17kg). Even 80years after release, the aqueous 1,4-dioxane concentration was still several orders-of-magnitude higher than potentially-applicable criteria. Within the downgradient plume, diffusion contributed to higher concentrations and enhanced penetration of 1,4-dioxane into the low-permeability zones relative to 1,1,1-TCA. In the second scenario, elevated 1,4-dioxane concentrations were predicted at a site impacted by migration of a weak source from an upgradient site. Plume cutoff was beneficial because it could be implemented in time to prevent further loading of the low-permeability zone at the downgradient site. Overall, this study documented that 1,4-dioxane within transmissive portions of the source zone is quickly depleted due to characteristics that favor both diffusion-based storage and groundwater transport, leaving little mass to treat using conventional means. Furthermore, the results highlight the differences between 1,4-dioxane and chlorinated solvent source zones, suggesting that back diffusion of 1,4-dioxane mass may be

  19. Assessment of seawater intrusion and nitrate contamination on the groundwater quality in the Korba coastal plain of Cap-Bon (North-east of Tunisia)

    Science.gov (United States)

    Zghibi, Adel; Tarhouni, Jamila; Zouhri, Lahcen

    2013-11-01

    In recent years, seawater intrusion and nitrate contamination of groundwater have become a growing concern for people in rural areas in Tunisia where groundwater is always used as drinking water. The coastal plain of Korba (north-east of Tunisia) is a typical area where the contamination of the aquifer in the form of saltwater intrusion and high nitrate concentrations is very developed and represents the major consequence of human activities. The objective of this study is to evaluate groundwater resource level, to determine groundwater quality and to assess the risk of NO3- pollution in groundwater using hydrogeochemical tools. Groundwater were sampled and analyzed for physic-chemical parameters: Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO3-, NO3-, Total Dissolved Solid and of the physical parameters (pH, electrical conductivity and the temperature). The interpretation of the analytical results is shown numerically and graphically through the ionic deviations, Piper Diagram, seawater fractions and binary diagrams. Moreover, electrical conductivity investigations have been used to identify the location of the major intrusion plumes in this coastal area and to obtain new information on the spatial scales and dynamics of the fresh water-seawater interface. Those processes can be used as indicators of seawater intrusion progression. First, the hydrogeochemical investigation of this aquifer reveals the major sources of contamination, represented by seawater intrusion. Thus, the intensive extraction of groundwater from aquifer reduces freshwater outflow to the sea, creates several drawdown cones and lowering of the water table to as much as 12 m below mean sea level in the center part of the study area especially between Diarr El Hojjej and Tafelloun villages, causing seawater migration inland and rising toward the wells. Moreover, the results of this study revealed the presence of direct cation exchange linked to seawater intrusion and dissolution processes associated with

  20. Arsenic, manganese and aluminum contamination in groundwater resources of Western Amazonia (Peru).

    Science.gov (United States)

    de Meyer, Caroline M C; Rodríguez, Juan M; Carpio, Edward A; García, Pilar A; Stengel, Caroline; Berg, Michael

    2017-12-31

    This paper presents a first integrated survey on the occurrence and distribution of geogenic contaminants in groundwater resources of Western Amazonia in Peru. An increasing number of groundwater wells have been constructed for drinking water purposes in the last decades; however, the chemical quality of the groundwater resources in the Amazon region is poorly studied. We collected groundwater from the regions of Iquitos and Pucallpa to analyze the hydrochemical characteristics, including trace elements. The source aquifer of each well was determined by interpretation of the available geological information, which identified four different aquifer types with distinct hydrochemical properties. The majority of the wells in two of the aquifer types tap groundwater enriched in aluminum, arsenic, or manganese at levels harmful to human health. Holocene alluvial aquifers along the main Amazon tributaries with anoxic, near pH-neutral groundwater contained high concentrations of arsenic (up to 700μg/L) and manganese (up to 4mg/L). Around Iquitos, the acidic groundwater (4.2≤pH≤5.5) from unconfined aquifers composed of pure sand had dissolved aluminum concentrations of up to 3.3mg/L. Groundwater from older or deeper aquifers generally was of good chemical quality. The high concentrations of toxic elements highlight the urgent need to assess the groundwater quality throughout Western Amazonia. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Human impacts on groundwater flow and contamination deduced by multiple isotopes in Seoul City, South Korea

    Energy Technology Data Exchange (ETDEWEB)

    Hosono, Takahiro, E-mail: hosono@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan); Ikawa, Reo, E-mail: r_ikawa@es.sci.kumamoto-u.ac.jp [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Shimada, Jun, E-mail: jshimada@sci.kumamoto-u.ac.jp [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Nakano, Takanori, E-mail: nakanot@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan); Saito, Mitsuyo, E-mail: misaito@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1, Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521 (Japan); Onodera, Shin-ichi, E-mail: sonodera@hiroshima-u.ac.jp [Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1, Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521 (Japan); Lee, Kang-Kun, E-mail: kklee@snu.ac.kr [School of Earth and Environmental Science, Seoul National University, San 56-1, Shinrim-dong, Kwanak-gu, Seoul 151-747 (Korea, Republic of); Taniguchi, Makoto, E-mail: makoto@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan)

    2009-04-15

    The influence of human activities on the flow system and contamination of groundwater were investigated in Seoul City, South Korea, one of the largest Asian cities, using a combination of isotopes ({delta}D, T, {delta}{sup 15}N, {delta}{sup 18}O, {delta}{sup 34}S, and {sup 87}Sr/{sup 86}Sr). Eighteen representative groundwater and river water samples, which were collected over a wide area of the city, were compared with previously reported data. The distribution of stable isotopes ({delta}D and {delta}{sup 18}O) with groundwater potential data shows that recharged groundwater from either the surrounding mountainous area as well as the Han River and other surface streams discharged towards the northern-central part of the city, where a subway tunnel pumping station is located. It is suggested from T values (3.3 to 5.8 T.U.) that groundwater was recharged in the last 30 to 40 years. The {delta}{sup 34}S and {delta}{sup 15}N of SO{sub 4}{sup 2-} and NO{sub 3}{sup -} data were efficiently used as indicators of contamination by human activities. These isotopes clarified that the contribution of anthropogenic contaminants i.e., industrial and household effluents, waste landfills, and fertilizers, are responsible for the enrichment by SO{sub 4}{sup 2-} (> 30 ppm as SO{sub 4}{sup 2-}) and NO{sub 3}{sup -} (> 20 ppm as NO{sub 3}{sup -}) of groundwater. The {sup 87}Sr/{sup 86}Sr values of groundwater vary (0.71326 to 0.75058) in accordance with the host rocks of different origins. Mineral elements such as Ca are also suggested to be derived naturally from rocks. The groundwater under Seoul City is greatly affected by transportation of pollutants along the groundwater flow controlled by subway tunnel pumping, contributing to the degradation of water quality in urbanized areas.

  2. Human impacts on groundwater flow and contamination deduced by multiple isotopes in Seoul City, South Korea

    International Nuclear Information System (INIS)

    Hosono, Takahiro; Ikawa, Reo; Shimada, Jun; Nakano, Takanori; Saito, Mitsuyo; Onodera, Shin-ichi; Lee, Kang-Kun; Taniguchi, Makoto

    2009-01-01

    The influence of human activities on the flow system and contamination of groundwater were investigated in Seoul City, South Korea, one of the largest Asian cities, using a combination of isotopes (δD, T, δ 15 N, δ 18 O, δ 34 S, and 87 Sr/ 86 Sr). Eighteen representative groundwater and river water samples, which were collected over a wide area of the city, were compared with previously reported data. The distribution of stable isotopes (δD and δ 18 O) with groundwater potential data shows that recharged groundwater from either the surrounding mountainous area as well as the Han River and other surface streams discharged towards the northern-central part of the city, where a subway tunnel pumping station is located. It is suggested from T values (3.3 to 5.8 T.U.) that groundwater was recharged in the last 30 to 40 years. The δ 34 S and δ 15 N of SO 4 2- and NO 3 - data were efficiently used as indicators of contamination by human activities. These isotopes clarified that the contribution of anthropogenic contaminants i.e., industrial and household effluents, waste landfills, and fertilizers, are responsible for the enrichment by SO 4 2- (> 30 ppm as SO 4 2- ) and NO 3 - (> 20 ppm as NO 3 - ) of groundwater. The 87 Sr/ 86 Sr values of groundwater vary (0.71326 to 0.75058) in accordance with the host rocks of different origins. Mineral elements such as Ca are also suggested to be derived naturally from rocks. The groundwater under Seoul City is greatly affected by transportation of pollutants along the groundwater flow controlled by subway tunnel pumping, contributing to the degradation of water quality in urbanized areas.

  3. Prioritization and accelerated remediation of groundwater contamination in the 200 Areas of the Hanford Site, Washington

    International Nuclear Information System (INIS)

    Wittreich, C.D.; Ford, B.H.

    1993-04-01

    The Hanford Site, operated by the US Department of Energy (DOE), occupies about 1,450 km 2 (560 mi 2 ) of the southeastern part of Washington State north of the confluence of the Yakima and Columbia Rivers. The Hanford Site is organized into numerically designated operational areas. The 200 Areas, located near the center of the Hanford Site, encompasses the 200 West, East and North Areas and cover an area of over 40 km 2 . The Hanford Site was originally designed, built, and operated to produce plutonium for nuclear weapons using production reactors and chemical reprocessing plants. Operations in the 200 Areas were mainly related to separation of special nuclear materials from spent nuclear fuel and contain related chemical and fuel processing and waste management facilities. Large quantities of chemical and radioactive waste associated with these processes were often disposed to the environment via infiltration structures such as cribs, ponds, ditches. This has resulted in over 25 chemical and radionuclide groundwater plumes, some of which have reached the Columbia River. An Aggregate Area Management Study program was implemented under the Hanford Federal Facility Agreement and Consent Order to assess source and groundwater contamination and develop a prioritized approach for managing groundwater remediation in the 200 Areas. This included a comprehensive evaluation of existing waste disposal and environmental monitoring data and the conduct of limited field investigations (DOE-RL 1992, 1993). This paper summarizes the results of groundwater portion of AAMS program focusing on high priority contaminant plume distributions and the groundwater plume prioritization process. The objectives of the study were to identify groundwater contaminants of concern, develop a conceptual model, refine groundwater contaminant plume maps, and develop a strategy to expedite the remediation of high priority contaminants through the implementation of interim actions

  4. [Simulation on contamination forecast and control of groundwater in a certain hazardous waste landfill].

    Science.gov (United States)

    Ma, Zhi-Fei; An, Da; Jiang, Yong-Hai; Xi, Bei-Dou; Li, Ding-Long; Zhang, Jin-Bao; Yang, Yu

    2012-01-01

    On the basis of site investigation and data collection of a certain hazardous waste landfill, the groundwater flow and solute transport coupled models were established by applying Visual Modflow software, which was used to conduct a numerical simulation that forecast the transport process of Cr6+ in groundwater and the effects of three control measures (ground-harden, leakage-proof barriers and drainage ditches) of contaminants transport after leachate leakage happened in impermeable layer of the landfill. The results show that the contamination plume of Cr6+ transports with groundwater flow direction, the contamination rang would reach the pool's boundary in 10 years, and the distance of contamination transport is 1 450 m. But the diffusion range of contamination plume would not be obviously expanded between 10 and 20 years. While the ground is hardened, the contamination plume would not reach the pool's boundary in 20 years. When the leakage-proof barrier is set in the bottom of water table aquifer, the concentration of Cr6+ is higher than that the leakage-proof barrier is unset, but the result is just opposite when setting the leakage-proof barrier in the bottom of underlying aquifer. The range of contamination plume is effectively controlled by setting drainage ditches that water discharge is 2 642 m3 x d(-1), which makes the monitoring wells would not be contaminated in 20 years. Moreover, combining the ground-harden with drainage ditches can get the best effect in controlling contaminants diffusion, and meanwhile, the drainage ditches' daily discharge is reduced to 1 878 m3 x d(-1). Therefore, it is suggested that the control measure combining the ground-harden with drainage ditches should apply to prevent contamination diffusion in groundwater when leachate leakage have happened in impermeable layer of the landfill.

  5. The far field migration of radionuclides in two dimensional groundwater flows though geologic media

    International Nuclear Information System (INIS)

    Ting, D.K.S.; Chambre, P.

    1985-01-01

    An analytical method to model the radionuclides migration in a two dimensional groundwater flor through geologic media has been developed and implemented into the computer code UCBNE21. Using this method, the potential hazard to the biosphere posed by the accidental release of radionuclides from a candidate repository site (WIPP) is determined. I-129 and Ra-226 are potentially the most hazardous nuclides in these sites but their discharge into the biosphere will not result in concentrations larger than their maximum permissible concentrations. (Author) [pt

  6. Assessment of the influences of groundwater colloids on the migration of technetium-99 at the Paducah Gaseous Diffusion Plant Site in Paducah, Kentucky

    International Nuclear Information System (INIS)

    Gu, B.; McDonald, J.A.; McCarthy, J.F.; Clausen, J.L.

    1994-07-01

    This short report summarizes the influences of groundwater colloids on the migration/transport of 99 Tc at the Paducah Gaseous Diffusion Plant (PGDP) site in Paducah, Kentucky. Limited data suggest that inorganic colloidal materials (e.g., aluminosilicate clay minerals) may not play a significant role in the retention and transport of Tc. Studies by size fractionation reveal that both Tc and natural organic matter (NOM) are largely present in the -8 mol/L or parts per billion), regardless of the redox conditions, Tc will stay in solution phase as TC(IV) or Tc(VII). The mechanisms of adsorption/association vs precipitation must be understood under reduced and low Tc conditions so that strategic plans for remediation of Tc contaminated soils and groundwaters can be developed

  7. Regulatory and Technical Issues Concerning the Detection and Treatment of NDMA-Contaminated Groundwater at NASA WSTF

    Science.gov (United States)

    Wiebe, D. T.; Zigmond, M. J.; Tufts, C. A.

    2002-01-01

    The National Aeronautics and Space Administration (NASA) White Sands Test Facility (WSTF) was established in 1963 primarily to provide rocket engine testing services for several NASA programs. The groundwater underlying the site has been contaminated as a result of historical operations. Groundwater contaminants include several volatile organic compounds (VOCs) and two semi-volatile compounds: N-nitrosodimethylamine (NDMA) and N-nitrodimethylamine (DMN). This paper discusses some of the technical, analytical, regulatory, and health risk issues associated with the contaminant plume. The plume has moved approximately 2.5 miles downgradient of the facility industrial boundary, with evidence of continued migration. As a result, NASA has proposed a pump and treat system using air strippers and ultraviolet (UV) oxidation to stabilize future movement of the contaminant plume. The system has been designed to treat 1,076 gallons (4,073 liters) per minute, with provisions for future expansion. The UV oxidation process was selected to treat NDMA-contaminated groundwater based on successes at other NDMA-contaminated sites. Bench- and pilot-scale testing of WSTF groundwater confirmed the ability of UV oxidation to destroy NDMA and generated sufficient data to design the proposed full-scale treatment system. NDMA is acutely toxic and is a probable human carcinogen. EPA-recommended health risk criteria for the residential consumption of NDMA/DMN-contaminated groundwater was used to determine that a 1.0 x 10(exp -6) excess cancer risk corresponds to 1.7 parts per trillion (ppt). EPA analytical methods are unable to detect NDMA and DMN in the low ppt range. EPA's current Appendix IX analytical method used to screen for NDMA, Method 8270, can detect NDMA only at levels that are orders of magnitude greater than the recommended health risk level. Additionally, EPA Method 607, the most sensitive EPA approved method, has a detection limit of 150 ppt. This corresponds to an excess cancer

  8. Interaction of groundwater and fresh basalt fissure surfaces and its effect on the migration of actinides

    International Nuclear Information System (INIS)

    Vandegrift, G.F.; Bowers, D.L.; Gerding, T.J.; Fried, S.M.; Wilbur, C.K.; Seitz, M.G.

    1983-01-01

    Experiments are being performed at Argonne National Laboratory (ANL): (1) to identify interactions of radionuclides and repository components that effect nuclide migration, and (2) to assess changes in nuclide migration caused by modifications expected upon aging of the waste, clay backfill, and rock. The experiments are conducted with radioactive borosilicate glass, bentonite and mechanically fissured basalt rock in flowing water analogous to their configuration in a breach of a nuclear waste repository. Changes undergone by the groundwater as it passed through the fissure include: (1) drop in pH from 10 to 8, (2) loss of suspended particulate, and (3) loss of dissolved/suspended U, Np, and Pu. These effects, also studied as functions of radiation dose and of laboratory aging of the repository components, are related to the predicted long-term performance of a nuclear waste repository

  9. Contaminants migration in the soil: the influence of transfer between the mobile and stationary phases

    International Nuclear Information System (INIS)

    Moreira, R.M.; Sabino, C.S.V.; Macedo, W.A.

    1996-01-01

    Three transport mechanisms control the contaminant migration in saturated soils: advection, diffusion and interchanges between liquid and solid phases. These interchanges define the retention by the soil and the contaminant delay related to the liquid phase flow. Therefore, the knowledge of the adsorption/desorption characteristics of the solute in solid surfaces is fundamental for the evaluation of toxic agent releases to the compartment soil. This communication reports the study which is being performed by the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) in this area, particularly with cesium and mercury by using X-ray absorption spectroscopy for contaminants migration

  10. To study the effects of groundwater contamination in Kasur due to Nallah Rohi

    International Nuclear Information System (INIS)

    Ghumman, A.R.; Shamim, M.A.

    2005-01-01

    Groundwater contamination is a worldwide known problem. Pakistan, being a developing country, is also facing the problem created by groundwater pollution. Disposal of domestic wastes and agricultural treatments has been reported to be a considerable factor for causing the pollution, especially the groundwater contamination. In the rural areas of Pakistan, latrines and septic tanks have become common because of the advancement in the living standards. All of the domestic wastes is disposed off into the ponds or nearby passing streams. In the similar fashion, drains in the big and well developed cities of Pakistan lead the domestic waste, along with the industrial waste, into the passing by streams, canals and rivers. All of such disposed off waste is untreated because of the lack of legislation and its improper implementation. The contaminated water affects the health of human beings and also destroys the crops when this water is used for irrigation. So this paper deals with the effects and condition of the disposal of the harmful chemicals, which ultimately through seepage reach the groundwater and make it hazardous. Also, the lateral distances of the contaminated groundwater were found out. For experimentation, major city of Kasur which is in the vicinity of Nullah Rohi, was selected. All the wastes including both the industrial as well as domestic, of the whole area, is disposed off into the Nullah. The percolation of the harmful chemicals and its mixing with groundwater has resulted in the hazardous effects on the inhabitants of the area on the irrigation land as well. So the water in the vicinity, at different locations was tested and the degree of contamination and the lateral distances of contaminated water were also worked out. (author)

  11. ASSESSMENT OF GROUNDWATER CONTAMINATION AROUND RECLAIMED MUNICIPAL LANDFILL – OTWOCK AREA, POLAND

    Directory of Open Access Journals (Sweden)

    Dorota Porowska

    2014-10-01

    Full Text Available The research was conducted around reclaimed landfill, located on the suburb of Otwock, around 25 km south-west of Warsaw. The objective of this study was to identify the chemical composition of groundwater and to determine the landfill impact on the chemical composition of groundwater downgrading from the landfill. Otwock landfill is located in very permeable area, where leachate quickly seeps into groundwater and plays a key role in controlling redox condition (and chemical composition of groundwater of the downgradient area. High concentrations of HCO3-, Cl-, Ca2+, Mg2+, Na+, K+, Fetot. as well as DOC in groundwater downgradient from the landfill (in comparison to background water likely indicate that groundwater quality is being significantly affected by leachate percolation. Currently, the load of contamination is released from landfill periodically and slowly moves (70 m/y in the aquifer along the flow direction. The effect of distance of the piezometer from the pollution source was also investigated. As expected, water from the nearest piezometer to the landfill showed the highest values of contaminant (water temperature, specific electrical conductivity, sodium, iron, chlorides (except for summer and autumn analysis and calcium (except for winter analysis. Chemical status of groundwater downgradient from the landfill is poor.

  12. Arsenic Contamination of Groundwater: A Review of Sources, Prevalence, Health Risks, and Strategies for Mitigation

    Directory of Open Access Journals (Sweden)

    Shiv Shankar

    2014-01-01

    Full Text Available Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial for mitigation of the problem of As contamination of groundwater.

  13. Arsenic contamination of groundwater: a review of sources, prevalence, health risks, and strategies for mitigation.

    Science.gov (United States)

    Shankar, Shiv; Shanker, Uma; Shikha

    2014-01-01

    Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial) for mitigation of the problem of As contamination of groundwater.

  14. Pollution potential of oil-contaminated soil on groundwater resources in Kuwait

    International Nuclear Information System (INIS)

    Literathy, P.; Quinn, M.; Al-Rashed, M.

    2003-01-01

    The only natural freshwater resource of Kuwait occurs as lenses floating on the saline groundwater in the northern part of the country, near to the oil fields. Rainwater is the only means of recharge of this limited groundwater resource. This groundwater is used as bottled drinking water and the fresh groundwater aquifer is considered as a strategic drinking water reserve for Kuwait. As a result of the 1991 Gulf War, the upper soil layer has been widely contaminated with crude oil and crude oil combustion products, which are potential pollutants likely affecting the groundwater resources. Significant efforts have been made to assess this pollution. These included: (a) a soil survey for assessing the soil contamination, and (b) leaching experiments to characterise the mobilization of the soil-associated pollutants. Fluorescence measurement techniques were used during field surveys as well as for laboratory testing. In addition, determination of the total extractable matter (TEM), total petroleum hydrocarbons (TPH), and GC/MS measurement of polyaromatic hydrocarbons (PAHs) were performed for the assessments. The laser induced fluorescence (LIF) measurement, having good correlation with the other laboratory measurements, was proved to provide necessary information for the assessment of the oil-contamination level in the desert soil. The subsequent leaching test with water demonstrated the mobilization of the fluorescing compounds (e.g. PAHs), and the alteration in the leaching characteristics of the contamination during the long term environmental weathering of the oil. (author)

  15. Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

    Energy Technology Data Exchange (ETDEWEB)

    K. Pohlmann; G. Pohll; J. Chapman; A. Hassan; R. Carroll; C. Shirley

    2004-03-01

    Groundwater flow and radionuclide transport at the Shoal underground nuclear test are characterized using three-dimensional numerical models, based on site-specific hydrologic data. The objective of this modeling is to provide the flow and transport models needed to develop a contaminant boundary defining the extent of radionuclide-contaminated groundwater at the site throughout 1,000 years at a prescribed level of confidence. This boundary will then be used to manage the Project Shoal Area for the protection of the public and the environment.

  16. Risk assessment for pesticide contamination of groundwater with sparse available data

    Science.gov (United States)

    Bardowicks, K.; Heredia, O.; Billib, M.; Fernández Cirelli, A.; Boochs, P.

    2009-04-01

    The contamination of the water resources by agrochemicals is recognized in industrial countries as a very important environmental problem, nevertheless in most of developing and threshold countries the risks for health and environmental problems are not considered. In these countries agrochemicals, which are forbidden since several years in Europe (e.g. atrazine), are still in use. In some threshold countries monitoring systems are already installed for nutrients (N, P) and also a few for heavy metals, but so far the contamination by pesticides is hardly ever controlled, thus there is no data available about pesticide concentrations in soil and water. The aim of this research is to develop a methodology to show farmers and other water users (water agencies, drinking water supply companies) in basins of developing or threshold countries with sparse available data the risk of contamination of the groundwater resources by pesticides. A few data like pesticide application, precipitation, irrigation, potential evaporation and soil types are available in some regions. If these data is reliable it can be used together with some justified estimated parameters to perform simulations of the fate of pesticides to the groundwater. Therefore in two study cases in Argentina and Chile pesticide models (e.g. PESTAN, IPTM-CS) were used to evaluate the risk of contamination of the groundwater. The results were compared with contamination indicators, like one developed by O. Heredia, for checking their plausibility. Afterwards the results of the models were used as input data for simulations at the catchment scale, for instance for a groundwater simulation model (VISUAL MODFLOW). The results show a great risk for the contamination of the groundwater resources in the selected study areas, especially by atrazine. On this account the findings will be used by local researchers to improve the knowledge and the awareness of farmers and other stakeholders about the contamination of the

  17. Development of Chemical Indicators of Groundwater Contamination Near the Carcass Burial Site

    Science.gov (United States)

    Kim, H.; Choi, J.; Kim, M.; Choi, J.; Lee, M.; Lee, H.; Jeon, S.; Bang, S.; Noh, H.; Yoo, J.; Park, S.; Kim, H.; Kim, D.; Lee, Y.; Han, J.

    2011-12-01

    A serious outbreak of foot and mouth disease (FMD) and avian influenza (AI) led to the culling of millions of livestock in South Korea from late 2010 to earlier 2011. Because of the scale of FMD and AI epidemic in Korea and rapid spread of the diseases, mass burial for the disposal of carcass was conducted to halt the outbreak. The improper construction of the burial site or inappropriate management of the carcass burial facility can cause the contamination of groundwater mainly due to the discharges of leachate through the base of disposal pit. The leachate from carcass burial contains by products of carcass decay such as amino acids, nitrate, ammonia and chloride. The presence of these chemical components in groundwater can be used as indicators demonstrating contamination of groundwater with leachate from carcass. The major concern about using these chemical indicators is that other sources including manures, fertilizers and waste waters from human or animal activities already exist in farming area. However, we lack the understanding of how groundwater contamination due to mass burial of carcass can be differentiated from the contamination due to livestock manures which shows similar chemical characteristics. The chemical compositions of the leachate from carcass burial site and the wastewater from livestock manure treatment facilities were compared. The chemical compositions considered include total organic carbon (TOC), total nitrogen (TN), nitrate, organic nitrogen (Organic nitrogen =TN-Ammonium Nitrogen- Nitrate nitrogen), ammonia, chloride, sodium, potassium and amino acids (20 analytes). The ratios of concentrations of the chemical compositions as indicators of contamination were determined to distinguish the sources of contamination in groundwater. Indicators which showed a linear relationship between two factors and revealed a distinct difference between the carcass leachate and livestock manure were chosen. In addition, the background level of the

  18. Groundwater flow model and its implications for contaminant behavior

    African Journals Online (AJOL)

    What sets hydrogeology apart from many of the other geosciences is an emphasis on treating problems mathematically. The mathematical approach involves representing a groundwater process by an equation and solving that equation. These equations are fundamental to the quantitative treatment of flow and provide the ...

  19. Bacterial Community Dynamics in Dichloromethane-Contaminated Groundwater Undergoing Natural Attenuation

    Directory of Open Access Journals (Sweden)

    Justin Wright

    2017-11-01

    Full Text Available The uncontrolled release of the industrial solvent methylene chloride, also known as dichloromethane (DCM, has resulted in widespread groundwater contamination in the United States. Here we investigate the role of groundwater bacterial communities in the natural attenuation of DCM at an undisclosed manufacturing site in New Jersey. This study investigates the bacterial community structure of groundwater samples differentially contaminated with DCM to better understand the biodegradation potential of these autochthonous bacterial communities. Bacterial community analysis was completed using high-throughput sequencing of the 16S rRNA gene of groundwater samples (n = 26 with DCM contamination ranging from 0.89 to 9,800,000 μg/L. Significant DCM concentration-driven shifts in overall bacterial community structure were identified between samples, including an increase in the abundance of Firmicutes within the most contaminated samples. Across all samples, a total of 6,134 unique operational taxonomic units (OTUs were identified, with 16 taxa having strong correlations with increased DCM concentration. Putative DCM degraders such as Pseudomonas, Dehalobacterium and Desulfovibrio were present within groundwater across all levels of DCM contamination. Interestingly, each of these taxa dominated specific DCM contamination ranges respectively. Potential DCM degrading lineages yet to be cited specifically as a DCM degrading organisms, such as the Desulfosporosinus, thrived within the most heavily contaminated groundwater samples. Co-occurrence network analysis revealed aerobic and anaerobic bacterial taxa with DCM-degrading potential were present at the study site. Our 16S rRNA gene survey serves as the first in situ bacterial community assessment of contaminated groundwater harboring DCM concentrations ranging over seven orders of magnitude. Diversity analyses revealed known as well as potentially novel DCM degrading taxa within defined DCM concentration

  20. Potential effects of groundwater and surface water contamination in an urban area, Qus City, Upper Egypt

    Science.gov (United States)

    Abdalla, Fathy; Khalil, Ramadan

    2018-05-01

    The potential effects of anthropogenic activities, in particular, unsafe sewage disposal practices, on shallow groundwater in an unconfined aquifer and on surface water were evaluated within an urban area by the use of hydrogeological, hydrochemical, and bacteriological analyses. Physicochemical and bacteriological data was obtained from forty-five sampling points based on33 groundwater samples from variable depths and 12 surface water samples. The pollution sources are related to raw sewage and wastewater discharges, agricultural runoff, and wastewater from the nearby Paper Factory. Out of the 33 groundwater samples studied, 17 had significant concentrations of NO3-, Cl- and SO42-, and high bacteria counts. Most of the water samples from the wells contained high Fe, Mn, Pb, Zn, Cd, and Cr. The majority of surface water samples presented high NO3- concentrations and high bacteria counts. A scatter plot of HCO3- versus Ca indicates that 58% of the surface water samples fall within the extreme contamination zone, while the others are within the mixing zone; whereas 94% of groundwater samples showed evidence of mixing between groundwater and wastewater. The bacteriological assessment showed that all measured surface and groundwater samples contained Escherichia coli and total coliform bacteria. A risk map delineated four classes of contamination, namely, those sampling points with high (39.3%), moderate (36.3%), low (13.3%), and very low (11.1%) levels of contamination. Most of the highest pollution points were in the middle part of the urban area, which suffers from unmanaged sewage and industrial effluents. Overall, the results demonstrate that surface and groundwater in Qus City are at high risk of contamination by wastewater since the water table is shallow and there is a lack of a formal sanitation network infrastructure. The product risk map is a useful tool for prioritizing zones that require immediate mitigation and monitoring.

  1. Remediation of arsenic-contaminated soils and groundwaters

    Science.gov (United States)

    Peters, Robert W.; Frank, James R.; Feng, Xiandong

    1998-01-01

    An in situ method for extraction of arsenic contaminants from a soil medium and remediation of the medium including contacting the medium with an extractant solution, directing the solution within and through the medium, and collecting the solution and contaminants. The method can also be used for arsenate and/or arsenite removal.

  2. Spatial interpolation methods and geostatistics for mapping groundwater contamination in a coastal area.

    Science.gov (United States)

    Elumalai, Vetrimurugan; Brindha, K; Sithole, Bongani; Lakshmanan, Elango

    2017-04-01

    Mapping groundwater contaminants and identifying the sources are the initial steps in pollution control and mitigation. Due to the availability of different mapping methods and the large number of emerging pollutants, these methods need to be used together in decision making. The present study aims to map the contaminated areas in Richards Bay, South Africa and compare the results of ordinary kriging (OK) and inverse distance weighted (IDW) interpolation techniques. Statistical methods were also used for identifying contamination sources. Na-Cl groundwater type was dominant followed by Ca-Mg-Cl. Data analysis indicate that silicate weathering, ion exchange and fresh water-seawater mixing are the major geochemical processes controlling the presence of major ions in groundwater. Factor analysis also helped to confirm the results. Overlay analysis by OK and IDW gave different results. Areas where groundwater was unsuitable as a drinking source were 419 and 116 km 2 for OK and IDW, respectively. Such diverse results make decision making difficult, if only one method was to be used. Three highly contaminated zones within the study area were more accurately identified by OK. If large areas are identified as being contaminated such as by IDW in this study, the mitigation measures will be expensive. If these areas were underestimated, then even though management measures are taken, it will not be effective for a longer time. Use of multiple techniques like this study will help to avoid taking harsh decisions. Overall, the groundwater quality in this area was poor, and it is essential to identify alternate drinking water source or treat the groundwater before ingestion.

  3. A calcite permeable reactive barrier for the remediation of Fluoride from spent potliner (SPL) contaminated groundwater

    DEFF Research Database (Denmark)

    Turner, B.D.; Binning, Philip John; Sloan, S.W.

    2008-01-01

    The use of calcite (CaCO3) as a substrate for a permeable reactive barrier (PRB) for removing fluoride from contaminated groundwater is proposed and is illustrated by application to groundwater contaminated by spent potliner leachate (SPL), a waste derived from the aluminium smelting process...... leachate indicate that the complex chemical matrix of the SPL leachate can impact fluoride removal significantly. For SPL contaminant mixtures, fluoride removal is initially less than expected from idealized, pure, solutions. However, with time, the effect of other contaminants on fluoride removal...... diminishes. Column tests also show that pH control is important for optimizing fluoride removal with the mass removed increasing with decreasing pH. Barrier pH can be regulated by CO2 addition with the point of injection being critical for optimising the remediation performance. Experimental and model...

  4. Re-thinking stressor interactions: The role of groundwater contamination impacting stream ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Sonne, Anne Thobo; Rønde, Vinni Kampman

    ) to quantify the contaminant discharges, and potentially link the chemical impact and stream water quality. Potential pollution sources include two contaminated sites (Grindstedfactory/landfill), aquaculture, waste water discharges, and diffuse sources from agriculture and urban areas. Datafor xenobiotic...... chronic stress level, so even small perturbations on top of changes in water flow or additional chemical stressors may be detrimental to the stream health. To address this issue, we identified contaminant sources and chemical stressors along a 16-km groundwater-fedstream stretch (Grindsted, Denmark...... organic groundwater contaminants, pesticides, heavy metals, general water chemistry, physical conditions and stream flow from three campaigns in 2012 and 2014 were assessed. The measured chemicalconcentrations were converted to toxic units (TU) based on 48-h acute toxicity tests with Daphnia magna...

  5. Land-use change and costs to rural households: a case study in groundwater nitrate contamination

    Science.gov (United States)

    Keeler, Bonnie L.; Polasky, Stephen

    2014-07-01

    Loss of grassland from conversion to agriculture threatens water quality and other valuable ecosystem services. Here we estimate how land-use change affects the probability of groundwater contamination by nitrate in private drinking water wells. We find that conversion of grassland to agriculture from 2007 to 2012 in Southeastern Minnesota is expected to increase the future number of wells exceeding 10 ppm nitrate-nitrogen by 45% (from 888 to 1292 wells). We link outputs of the groundwater well contamination model to cost estimates for well remediation, well replacement, and avoidance behaviors to estimate the potential economic value lost due to nitrate contamination from observed land-use change. We estimate 0.7-12 million in costs (present values over a 20 year horizon) to address the increased risk of nitrate contamination of private wells. Our study demonstrates how biophysical models and economic valuation can be integrated to estimate the welfare consequences of land-use change.

  6. Land-use change and costs to rural households: a case study in groundwater nitrate contamination

    International Nuclear Information System (INIS)

    Keeler, Bonnie L; Polasky, Stephen

    2014-01-01

    Loss of grassland from conversion to agriculture threatens water quality and other valuable ecosystem services. Here we estimate how land-use change affects the probability of groundwater contamination by nitrate in private drinking water wells. We find that conversion of grassland to agriculture from 2007 to 2012 in Southeastern Minnesota is expected to increase the future number of wells exceeding 10 ppm nitrate-nitrogen by 45% (from 888 to 1292 wells). We link outputs of the groundwater well contamination model to cost estimates for well remediation, well replacement, and avoidance behaviors to estimate the potential economic value lost due to nitrate contamination from observed land-use change. We estimate $0.7–12 million in costs (present values over a 20 year horizon) to address the increased risk of nitrate contamination of private wells. Our study demonstrates how biophysical models and economic valuation can be integrated to estimate the welfare consequences of land-use change. (letter)

  7. Sources, migration and transformation of antimony contamination in the water environment of Xikuangshan, China: Evidence from geochemical and stable isotope (S, Sr) signatures

    International Nuclear Information System (INIS)

    Wen, Bing; Zhou, Jianwei; Zhou, Aiguo; Liu, Cunfu; Xie, Lina

    2016-01-01

    The Xikuangshan (XKS) mine in central China is the largest antimony (Sb) mine in the world. The mining activity has seriously contaminated the waters in the area. To determine the sources, migration and transformation of Sb contamination, 32 samples from groundwater (aquifer water), surface water and mine water were collected for water chemistry, trace element and S_S_O_4 and Sr stable isotope analyses. The results showed that the groundwater and surface water were in an oxidized environment. The S_S_O_4 and Sr isotope compositions in the water indicated that dissolved Sb and SO_4"2 originated from sulfide mineral (Sb_2S_3) oxidation, whereas radiogenic Sr may have been sourced from silicified limestone and stibnite in the Shetianqiao aquifer. Furthermore, a positive correlation between δ"3"4S_S_O_4 and δ"8"7Sr values revealed that the Sr, S and Sb in the waters had a common contamination source, i.e., silicified limestone and stibnite, whereas the Sr, S and Sb in rock and ore were sourced from Proterozoic basement clastics. The analysis also indicated that the isotope composition of dissolved SO_4"2 "− had been influenced by slight bacterial SO_4 reduction in the Magunao aquifer. Mining or rock collapse may have caused Shetianqiao aquifer water to contaminate the Magunao aquifer water via mixing. This study has demonstrated that the stable isotopes of "3"4S_S_O_4 and "8"7Sr, combined with hydrochemical methods, are effective in tracking the sources, migration and transformation of Sb contamination. - Highlights: • Mining activities at XKS mine have caused serious water contamination. • The characteristics of Sb contamination in water environment are still unclear. • Combine S isotopes of sulfate and Sr isotopes with hydrochemical methods. • Sr, S, and Sb in natural water had a common source: silicified limestone and stibnite. • Shetianqiao aquifer water contaminated the Magunao aquifer water via mixing.

  8. The effect of vadose zone heterogeneities on vapor phase migration and aquifer contamination by volatile organics

    Energy Technology Data Exchange (ETDEWEB)

    Seneviratne, A.; Findikakis, A.N. [Bechtel Corporation, San Francisco, CA (United States)

    1995-03-01

    Organic vapors migrating through the vadose zone and inter-phase transfer can contribute to the contamination of larger portions of aquifers than estimated by accounting only for dissolved phase transport through the saturated zone. Proper understanding of vapor phase migration pathways is important for the characterization of the extent of both vadose zone and the saturated zone contamination. The multiphase simulation code T2VOC is used to numerically investigate the effect of heterogeneties on the vapor phase migration of chlorobenzene at a hypothetical site where a vapor extraction system is used to remove contaminants. Different stratigraphies consisting of alternate layers of high and low permeability materials with soil properties representative of gravel, sandy silt and clays are evaluated. The effect of the extent and continuity of low permeability zones on vapor migration is evaluated. Numerical simulations are carried out for different soil properties and different boundary conditions. T2VOC simulations with zones of higher permeability were made to assess the role of how such zones in providing enhanced migration pathways for organic vapors. Similarly, the effect of the degree of saturation of the porous medium on vapor migration was for a range of saturation values. Increased saturation reduces the pore volume of the medium available for vapor diffusion. Stratigraphic units with higher aqueous saturation can retard the vapor phase migration significantly.

  9. 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

  10. Characteristics of petroleum-contaminated groundwater during natural attenuation: a case study in northeast China.

    Science.gov (United States)

    Qian, Hong; Zhang, Yuling; Wang, Jiali; Si, Chaoqun; Chen, Zaixing

    2018-01-13

    The objective of this study was to investigate a petroleum-contaminated groundwater site in northeast China. We determined the physicochemical properties of groundwater that contained total petroleum hydrocarbons (TPH) with a view to developing a scientifically robust strategy for controlling and remediating pollution of groundwater already contaminated with petroleum. Samples were collected at regular intervals and were analyzed for dissolved oxygen (DO), iron (Fe 3+ ), sulfate (SO 4 2- ), electrical conductivity (Eh), pH, hydrogen carbonate (HCO 3 - ), and enzyme activities of catalase (CAT), peroxidase (HRP), catechol 1,2-dioxygenase (C12O), and catechol 2,3-dioxygenase (C23O). We used factor analysis in SPSS to determine the main environmental characteristics of the groundwater samples. The results confirmed that the study site was slightly contaminated and that TPH levels were decreasing slightly. Some of the physicochemical variables showed regular fluctuations; DO, Fe 3+ , and SO 4 2- contents decreased gradually, while the concentrations of one of the microbial degradation products, HCO 3 - , increased. Microorganism enzyme activities decreased gradually. The microbiological community deteriorated noticeably during the natural attenuation process, so microbiological degradation of pollutants receded gradually. The HCO 3 - content increased and the pH and Eh decreased gradually. The groundwater environment tended to be reducing.

  11. Toxicological and chemical assessment of arsenic-contaminated groundwater after electrochemical and advanced oxidation treatments.

    Science.gov (United States)

    Radić, Sandra; Crnojević, Helena; Vujčić, Valerija; Gajski, Goran; Gerić, Marko; Cvetković, Želimira; Petra, Cvjetko; Garaj-Vrhovac, Vera; Oreščanin, Višnja

    2016-02-01

    Owing to its proven toxicity and mutagenicity, arsenic is regarded a principal pollutant in water used for drinking. The objective of this study was the toxicological and chemical evaluation of groundwater samples obtained from arsenic enriched drinking water wells before and after electrochemical and ozone-UV-H2O2-based advanced oxidation processes (EAOP). For this purpose, acute toxicity test with Daphnia magna and chronic toxicity test with Lemna minor L. were employed as well as in vitro bioassays using human peripheral blood lymphocytes (HPBLs). Several oxidative stress parameters were estimated in L.minor. Physicochemical analysis showed that EAOP treatment was highly efficient in arsenic but also in ammonia and organic compound removal from contaminated groundwater. Untreated groundwater caused only slight toxicity to HPBLs and D. magna in acute experiments. However, 7-day exposure of L. minor to raw groundwater elicited genotoxicity, a significant growth inhibition and oxidative stress injury. The observed genotoxicity and toxicity of raw groundwater samples was almost completely eliminated by EAOP treatment. Generally, the results obtained with L. minor were in agreement with those obtained in the chemical analysis suggesting the sensitivity of the model organism in monitoring of arsenic-contaminated groundwater. In parallel to chemical analysis, the implementation of chronic toxicity bioassays in a battery is recommended in the assessment of the toxic and genotoxic potential of such complex mixtures. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Fingerprinting groundwater pollution in catchments with contrasting contaminant sources using microorganic compounds.

    Science.gov (United States)

    Stuart, Marianne E; Lapworth, Dan J; Thomas, Jenny; Edwards, Laura

    2014-01-15

    Evaluating the occurrence of microorganics helps to understand sources and processes which may be controlling the transport and fate of emerging contaminants (ECs). A study was carried out at the contrasting instrumented environmental observatory sites at Oxford, on the peri-urban floodplain gravel aquifer of the River Thames and Boxford, in the rural valley of the River Lambourn on the chalk aquifer, in Southern England to explore the use of ECs to fingerprint contaminant sources and flow pathways in groundwater. At Oxford compounds were typical of a local waste tip plume (not only plasticisers and solvents but also barbiturates and N,N-diethyl-m-toluamide (DEET)) and of the urban area (plasticisers and mood-enhancing drugs such as carbamazepine). At Boxford the results were different with widespread occurrence of agricultural pesticides, their metabolites and the solvent trichloroethene, as well as plasticisers, caffeine, butylated food additives, DEET, parabens and trace polyaromatic hydrocarbons (PAHs). Groups of compounds used in pharmaceuticals and personal care products of different provenance in the environment could be distinguished, i) historical household and medical waste, ii) long-term household usage persistent in groundwater and iii) current usage and contamination from surface water. Co-contaminant and degradation products can also indicate the likely source of contaminants. A cocktail of contaminants can be used as tracers to provide information on catchment pathways and groundwater/surface water interactions. A prominent feature in this study is the attenuation of many EC compounds in the hyporheic zone. © 2013.

  13. Investigation of shallow groundwater contamination near East Fork Poplar Creek, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Carmichael, J.K.

    1989-01-01

    Alluvial soils of the flood plain of East Fork Poplar Creek in Oak Ridge, Tennessee, are contaminated with mercury and other metals, organic compounds, and radionuclides originating from the Y-12 Plant, a nuclear-processing facility located within the US Department of Energy's Oak Ridge Reservation. Observation wells were installed in the shallow aquifer of the flood plain, and water quality samples were collected to determine if contaminants are present in the shallow groundwater. Groundwater in the shallow aquifer occurs under water-table conditions. Recharge is primarily from precipitation and discharge is to East Fork Poplar Creek. Groundwater levels fluctuate seasonally in response to variations in recharge and evapotranspiration. During extremely dry periods, the water table drops below the base of the shallow aquifer in some flood-plain areas. Contaminants were found in water samples from several of the wells in concentrations which equaled or exceeded drinking-water standards established by the US Environmental Protection Agency are antimony, chromium, lead, mercury, selenium, phenols, and strontium-90. Total and dissolved uranium concentrations exceeded the analytical detection limit in nearly 70% of the wells in the flood plain. The results of water quality determinations demonstrate that elevated concentrations of most trace metals (and possibly organic compounds and radionuclides) were caused by contaminated sediments in the samples. The presence of contaminated sediment in samples is suspected to be the result of borehole contamination during well installation. 21 refs., 20 figs., 6 tabs

  14. Study of a waste disposal site and it's groundwater contamination ...

    African Journals Online (AJOL)

    The choice of an old borrow pit at Avu village in the outskirts of Owerri Urban as the permanent dump for wastes from Owerri Urban is evaluated in terms of the hydrogeology of the site. The depth to the groundwater table or the vadose zone is 9 – 9.5m; the texture of the soils shows fine attenuative materials that can inhibit ...

  15. Correlation of BTEX levels and toxicity of condensate contaminated groundwater

    International Nuclear Information System (INIS)

    Headley, J.; Goudey, S.; Birkholz, D.; Hardisty, P.

    1995-01-01

    The concentration of BTEX was determined for 60 groundwater samples collected from 6 gas plants in Western Canada, using conventional purge-and-trap GC/MS procedures. The gas plants were selected to cover different types of operations with different amine process chemicals employed for the sweetening of the raw sour-gas condensates. Aliquots of the ground water samples were subjected to toxicity screening tests, specifically, (a) bacterial luminescence (microtox); (b) daphnia mortality and (c) fathead minnow mortality. For the toxicity tests, sample handling procedures were developed to minimize the loss of volatile organics during the experiments. To account for possible losses, the levels of BTEX were monitored at the start and upon completion of these tests. The results indicated that the toxicity of the groundwater was in general, well correlated to the concentration of BTEX (primarily xylene). Approximately 5% of the samples, however, were observed to be toxic although the concentration of BTEX were below the method detection limit (1 microg/1). Thiophenic volatile organics were implicated for the latter. Based on the laboratory results, the remediation of BTEX is expected to correlate with the removal of the toxicity of the groundwater. These findings are of direct relevance to present technologies employed for remediation of ground water at the Sourgas plants

  16. Influence Of Groundwater Discharge On Arsenic Contamination In Sediments

    Science.gov (United States)

    A field investigation was conducted to evaluate the impact of a discharging arsenic plume on sediment contaminant characteristics at a site adjacent to a landfill in northeastern Massachusetts. Site characterization included assessment of the hydrologic and chemical samples coll...

  17. The Use of Bacteria for Remediation of Mercury Contaminated Groundwater

    Science.gov (United States)

    Many processes of mercury transformation in the environment are bacteria mediated. Mercury properties cause some difficulties of remediation of mercury contaminated environment. Despite the significance of the problem of mercury pollution, methods of large scale bioremediation ...

  18. Heavy metal contamination and its indexing approach for groundwater of Goa mining region, India

    Science.gov (United States)

    Singh, Gurdeep; Kamal, Rakesh Kant

    2017-06-01

    The objective of the study is to reveal the seasonal variations in the groundwater quality with respect to heavy metal contamination. To get the extent of the heavy metals contamination, groundwater samples were collected from 45 different locations in and around Goa mining area during the monsoon and post-monsoon seasons. The concentration of heavy metals, such as lead, copper, manganese, zinc, cadmium, iron, and chromium, were determined using atomic absorption spectrophotometer. Most of the samples were found within limit except for Fe content during the monsoon season at two sampling locations which is above desirable limit, i.e., 300 µg/L as per Indian drinking water standard. The data generated were used to calculate the heavy metal pollution index (HPI) for groundwater. The mean values of HPI were 1.5 in the monsoon season and 2.1 in the post-monsoon season, and these values are well below the critical index limit of 100.

  19. Modeling Contamination Migration on the Chandra X-Ray Observatory - III

    Science.gov (United States)

    O'Dell, Stephen L.; Swartz, Douglas A.; Tice, Neil W.; Plucinsky, Paul P.; Grant, Catherine E.; Marshall, Herman L.; Vikhlinin, Alexy A.; Tennant, Allyn F.; Dahmer, Matthew T.

    2015-01-01

    During its first 16 years of operation, the cold (about -60 C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition have changed. This evolution has motivated further analysis of contamination migration within and near the ACIS cavity, in part to evaluate potential bake-out scenarios intended to reduce the level of contamination. Keywords: X-ray astronomy, CCDs, contamination, modeling and simulation, spacecraft operations

  20. Testing of a benchscale Reverse Osmosis/Coupled Transport system for treating contaminated groundwater

    International Nuclear Information System (INIS)

    Hodgson, K.M.; Lunsford, T.R.; Panjabi, G.

    1994-01-01

    The Reverse Osmosis/Coupled Transport process is a innovative means of removing radionuclides from contaminated groundwater at the Hanford Site. Specifically, groundwater in the 200 West Area of the Hanford Site has been contaminated with uranium, technetium, and nitrate. Investigations are proceeding to determine the most cost effective method to remove these contaminants. The process described in this paper combines three different membrane technologies (reverse osmosis, coupled transport, and nanofiltration to purify the groundwater while extracting and concentrating uranium, technetium, and nitrate into separate solutions. This separation allows for the future use of the radionuclides, if needed, and reduces the amount of waste that will need to be disposed of. This process has the potential to concentrate the contaminants into solutions with volumes in a ratio of 1/10,000 of the feed volume. This compares to traditional volume reductions of 10 to 100 for ion exchange and stand-alone reverse osmosis. The successful demonstration of this technology could result in significant savings in the overall cost of decontaminating the groundwater

  1. SURFACE-ALTERED ZEOLITES AS PERMEABLE BARRIERS FOR IN SITU TREATMENT OF CONTAMINATED GROUNDWATER

    International Nuclear Information System (INIS)

    Bowman, Robert S.; Li, Zhaohui; Roy, Stephen J.; Burt, Todd; Johnson, Timothy L.; Johnson, Richard L.

    1999-01-01

    The overall objective of this effort is to develop and test a zeolite-based permeable barrier system for containing and remediating contaminated groundwater. The projected product is an engineered and tested permeable barrier system that can be adopted by the commercial sector

  2. Evidence for groundwater contamination by heavy metals through soil passage under acidifying conditions

    NARCIS (Netherlands)

    Wilkens, B.J.

    1995-01-01

    The research reported here is aimed at improving the knowledge of the mobility of the heavy metals cadmium and zinc in vulnerable soil types. We use the term vulnerable with reference to vulnerability of groundwater for contamination by soil leaching. At diffuse soil immissions of heavy metals,

  3. Evidence for groundwater contamination by heavy metals through soil passage under acidifying conditions

    NARCIS (Netherlands)

    Wilkens, B.J,

    1995-01-01

    The research reported here is aimed at improving the knowledge of the mobility of the heavy metals cadmium and zinc in vulnerable soil types. We use the term vulnerable with reference to vulnerability of groundwater for contamination by soil leaching. At diffuse soil immissions of heavy

  4. Grand challenge problems in environmental modeling and remediation: groundwater contaminant transport

    Energy Technology Data Exchange (ETDEWEB)

    Todd Arbogast; Steve Bryant; Clint N. Dawson; Mary F. Wheeler

    1998-08-31

    This report describes briefly the work of the Center for Subsurface Modeling (CSM) of the University of Texas at Austin (and Rice University prior to September 1995) on the Partnership in Computational Sciences Consortium (PICS) project entitled Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport.

  5. Establishing indices for groundwater contamination risk assessment in the vicinity of hazardous waste landfills in China

    International Nuclear Information System (INIS)

    Li Ying; Li Jinhui; Chen Shusheng; Diao Weihua

    2012-01-01

    Groundwater contamination by leachate is the most damaging environmental impact over the entire life of a hazardous waste landfill (HWL). With the number of HWL facilities in China rapidly increasing, and considering the poor status of environmental risk management, it is imperative that effective environmental risk management methods be implemented. A risk assessment indices system for HWL groundwater contamination is here proposed, which can simplify the risk assessment procedure and make it more user-friendly. The assessment framework and indices were drawn from five aspects: source term, underground media, leachate properties, risk receptors and landfill management quality, and a risk assessment indices system consisting of 38 cardinal indicators was established. Comparison with multimedia models revealed that the proposed indices system was integrated and quantitative, that input data for it could be easily collected, and that it could be widely used for environmental risk assessment (ERA) in China. - Highlights: ► No comprehensive environmental risk assessment method for hazardous waste management is proposed in China. ► An assessment indices system is established for groundwater contamination in the vicinity of hazardous waste landfill. ► All indicators are quantitative and applicable in China. - Capsule: This research identified critical indices and established a system for environmental risk assessment for groundwater contamination in the vicinity of HWLs in China.

  6. Effect of hydrocarbon-contaminated fluctuating groundwater on magnetic properties of shallow sediments

    Czech Academy of Sciences Publication Activity Database

    Ameen, N. N.; Klueglein, N.; Appel, E.; Petrovský, Eduard; Kappler, A.; Leven, C.

    2014-01-01

    Roč. 58, č. 3 (2014), s. 442-460 ISSN 0039-3169 R&D Projects: GA MŠk(CZ) LG13042 Institutional support: RVO:67985530 Keywords : environmental magnetism * magnetic susceptibility * groundwater table fluctuation * hydrocarbon contamination * magnetite formation Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.806, year: 2014

  7. Change of magnetic properties due to fluctuations of hydrocarbon contaminated groundwater in unconsolidated sediments

    Czech Academy of Sciences Publication Activity Database

    Rijal, M. L.; Appel, E.; Petrovský, Eduard; Blaha, U.

    2010-01-01

    Roč. 158, č. 5 (2010), s. 1756-1762 ISSN 0269-7491 Institutional research plan: CEZ:AV0Z30120515 Keywords : hydrocarbon contamination * groundwater table fluctuation * magnetic properties * environmental magnetism Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 3.395, year: 2010

  8. SURFACE-ALTERED ZEOLITES AS PERMEABLE BARRIERS FOR IN SITU TREATMENT OF CONTAMINATED GROUNDWATER

    Energy Technology Data Exchange (ETDEWEB)

    Robert S. Bowman; Zhaohui Li; Stephen J. Roy; Todd Burt; Timothy L. Johnson; Richard L. Johnson

    1999-08-30

    The overall objective of this effort is to develop and test a zeolite-based permeable barrier system for containing and remediating contaminated groundwater. The projected product is an engineered and tested permeable barrier system that can be adopted by the commercial sector.

  9. Development and application of a novel method for regional assessment of groundwater contamination risk in the Songhua River Basin.

    Science.gov (United States)

    Nixdorf, Erik; Sun, Yuanyuan; Lin, Mao; Kolditz, Olaf

    2017-12-15

    The main objective of this study is to quantify the groundwater contamination risk of Songhua River Basin by applying a novel approach of integrating public datasets, web services and numerical modelling techniques. To our knowledge, this study is the first to establish groundwater risk maps for the entire Songhua River Basin, one of the largest and most contamination-endangered river basins in China. Index-based groundwater risk maps were created with GIS tools at a spatial resolution of 30arc sec by combining the results of groundwater vulnerability and hazard assessment. Groundwater vulnerability was evaluated using the DRASTIC index method based on public datasets at the highest available resolution in combination with numerical groundwater modelling. As a novel approach to overcome data scarcity at large scales, a web mapping service based data query was applied to obtain an inventory for potential hazardous sites within the basin. The groundwater risk assessment demonstrated that contamination risk. These areas were mainly located in the vast plain areas with hotspots particularly in the Changchun metropolitan area. Moreover, groundwater levels and pollution point sources were found to play a significantly larger impact in assessing these areas than originally assumed by the index scheme. Moderate contamination risk was assigned to 27% of the aquifers, predominantly associated with less densely populated agricultural areas. However, the majority of aquifer area in the sparsely populated mountain ranges displayed low groundwater contamination risk. Sensitivity analysis demonstrated that this novel method is valid for regional assessments of groundwater contamination risk. Despite limitations in resolution and input data consistency, the obtained groundwater contamination risk maps will be beneficial for regional and local decision-making processes with regard to groundwater protection measures, particularly if other data availability is limited. Copyright

  10. Soil treatment and groundwater control for No. 6 fuel oil and PCB contamination

    International Nuclear Information System (INIS)

    Girioni, M.J.; St. Hilaire, W.J.

    1991-01-01

    This paper reports that as part of a Short-Term Measure ordered by the Massachusetts Department of Environmental Protection (DEP), soil contaminated by No. 6 fuel oil and low-level polychlorinated biphenyls (PCBs) was excavated, treated and recycled on-site as an asphalt base course for a parking lot at an industrial complex in New Bedford, Massachusetts. Approximately 300 cubic yards of contaminated soil were treated with an asphalt emulsion and utilized as a aggregate component for asphalt processed at ambient temperatures during the month of December 1990. In order to determine if the contaminated soils to be recycled would be classified as a hazardous waste (as defined by the Massachusetts Hazardous Waste Regulations, 310 CMR 30.000), or if the soil to be recycled would pose a significant risk to health, safety or the environment, analytical testing of the contaminated soil was conducted prior, during and after treatment. Analytical testing included Toxicity Characteristics Leaching Procedure (TCLP) analyses of the untreated and treated soil. An alternative solution to the standard groundwater pump-and-treat method was designed and constructed to control and recover the highly viscous floating petroleum product. A series of precast leaching galleys (oil collection chambers) and a precast leach pit (groundwater discharge structure) were constructed to alter the local groundwater table to induce groundwater flow by gravity into the leaching chambers. Passive (i.e., nonpumping) groundwater flow to the leaching chambers was induced by placing of the groundwater discharge structure hydraulically downgradient of the leaching chambers. Collected oil, separated by gravity, will be periodically vacuumed, as necessary, for proper off-site disposal. Excess water discharges to the downgradient leach pit

  11. A national-scale assessment of micro-organic contaminants in groundwater of England and Wales.

    Science.gov (United States)

    Manamsa, Katya; Crane, Emily; Stuart, Marianne; Talbot, John; Lapworth, Dan; Hart, Alwyn

    2016-10-15

    A large variety of micro-organic (MO) compounds is used in huge quantities for a range of purposes (e.g. manufacturing, food production, healthcare) and is now being frequently detected in the aquatic environment. Interest in the occurrence of MO contaminants in the terrestrial and aquatic environments continues to grow, as well as in their environmental fate and potential toxicity. However, the contamination of groundwater resources by MOs has a limited evidence base compared to other freshwater resources. Of particular concern are newly 'emerging contaminants' such as pharmaceuticals and lifestyle compounds, particularly those with potential endocrine disrupting properties. While groundwater often has a high degree of protection from pollution due to physical, chemical and biological attenuation processes in the subsurface compared to surface aquatic environments, trace concentrations of a large range of compounds are still detected in groundwater and in some cases may persist for decades due to the long residence times of groundwater systems. This study provides the first national-scale assessment of micro-organic compounds in groundwater in England and Wales. A large set of monitoring data was analysed to determine the relative occurrence and detected concentrations of different groups of compounds and to determine relationships with land-use, aquifer type and groundwater vulnerability. MOs detected including emerging compounds such as caffeine, DEET, bisphenol A, anti-microbial agents and pharmaceuticals as well as a range of legacy contaminants including chlorinated solvents and THMs, petroleum hydrocarbons, pesticides and other industrial compounds. There are clear differences in MOs between land-use types, particularly for urban-industrial and natural land-use. Temporal trends of MO occurrence are assessed but establishing long-term trends is not yet possible. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.

  12. 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.

  13. Influence of the Pressure Difference and Door Swing on Heavy Contaminants Migration between Rooms.

    Science.gov (United States)

    Hendiger, Jacek; Chludzińska, Marta; Ziętek, Piotr

    2016-01-01

    This paper presents the results of investigations whose aim was to describe the influence of the pressure difference level on the ability of contaminants migration between neighbouring rooms in dynamic conditions associated with door swing. The analysis was based on airflow visualization made with cold smoke, which simulated the heavy contaminants. The test room was pressurized to a specific level and then the door was opened to observe the trail of the smoke plume in the plane of the door. The door was opened in both directions: to the positively and negatively pressurized room. This study focuses on the visualization of smoke plume discharge and an uncertainty analysis is not applicable. Unlike other studies which focus on the analysis of pressure difference, the present study looks at the contaminants which are heavier than air and on "pumping out" the contaminants by means of door swing. Setting the proper level of pressure difference between the contaminated room and the neighbouring rooms can prove instrumental in ensuring protection against toxic contaminants migration. This study helped to establish the threshold of pressure difference necessary to reduce migration of heavy contaminants to neighbouring rooms.

  14. Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-01

    This report evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells to determine the potential for immediate human health and environmental impacts. This risk assessment evaluates the most contaminated groundwater that flows beneath the processing site towards the Gunnison River. The monitor wells that have consistently shown the highest concentration of most contaminants are used in this risk assessment. This risk assessment will be used in conjunction with additional activities and documents to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium.

  15. In situ treatment of mixed contaminants in groundwater: Application of zero-valence iron and palladized iron for treatment of groundwater contaminated with trichloroethene and technetium-99

    International Nuclear Information System (INIS)

    Korte, N.E.; Muck, M.T.; Zutman, J.L.; Schlosser, R.M.; Liang, L.; Gu, B.; Houk, T.C.; Fernando, Q.

    1997-04-01

    The overall goal of this portion of the project was to package one or more unit processes, as modular components in vertical and/or horizontal recirculation wells, for treatment of volatile organic compounds (VOCs) [e.g., trichloroethene (TCE)] and radionuclides [e.g., technetium (Tc) 99 ] in groundwater. The project was conceived, in part, because the coexistence of chlorinated hydrocarbons and radionuclides has been identified as the predominant combination of groundwater contamination in the US Department of Energy (DOE) complex. Thus, a major component of the project was the development of modules that provide simultaneous treatment of hydrocarbons and radionuclides. The project objectives included: (1) evaluation of horizontal wells for inducing groundwater recirculation, (2) development of below-ground treatment modules for simultaneous removal of VOCs and radionuclides, and (3) demonstration of a coupled system (treatment module with recirculation well) at a DOE field site where both VOCs and radionuclides are present in the groundwater. This report is limited to the innovative treatment aspects of the program. A report on pilot testing of the horizontal recirculation system was the first report of the series (Muck et al. 1996). A comprehensive report that focuses on the engineering, cost and hydrodynamic aspects of the project has also been prepared (Korte et al. 1997a)

  16. In situ treatment of mixed contaminants in groundwater: Application of zero-valence iron and palladized iron for treatment of groundwater contaminated with trichloroethene and technetium-99

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.E.; Muck, M.T.; Zutman, J.L.; Schlosser, R.M. [Oak Ridge National Lab., Grand Junction, CO (United States); Liang, L.; Gu, B. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Siegrist, R.L. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.]|[Colorado School of Mines, Golden, CO (United States); Houk, T.C. [Portsmouth Gaseous Diffusion Plant, Piketon, OH (United States); Fernando, Q. [Univ. of Arizona, Tucson, AZ (United States)

    1997-04-01

    The overall goal of this portion of the project was to package one or more unit processes, as modular components in vertical and/or horizontal recirculation wells, for treatment of volatile organic compounds (VOCs) [e.g., trichloroethene (TCE)] and radionuclides [e.g., technetium (Tc){sup 99}] in groundwater. The project was conceived, in part, because the coexistence of chlorinated hydrocarbons and radionuclides has been identified as the predominant combination of groundwater contamination in the US Department of Energy (DOE) complex. Thus, a major component of the project was the development of modules that provide simultaneous treatment of hydrocarbons and radionuclides. The project objectives included: (1) evaluation of horizontal wells for inducing groundwater recirculation, (2) development of below-ground treatment modules for simultaneous removal of VOCs and radionuclides, and (3) demonstration of a coupled system (treatment module with recirculation well) at a DOE field site where both VOCs and radionuclides are present in the groundwater. This report is limited to the innovative treatment aspects of the program. A report on pilot testing of the horizontal recirculation system was the first report of the series (Muck et al. 1996). A comprehensive report that focuses on the engineering, cost and hydrodynamic aspects of the project has also been prepared (Korte et al. 1997a).

  17. Studies on groundwater flow and radionuclide migration at underground environments. Final report of collaboration research between JAERI and AECL

    International Nuclear Information System (INIS)

    Ogawa, Hiromichi; Nagao, Seiya; Yamaguchi, Tetsuji

    2001-01-01

    The Japan Atomic Energy Research Institute (JAERI) conducted a collaboration program Phase II with the Atomic Energy of Canada Limited (AECL) from 1994 to 1998. The program was started to contribute the establishment of safety assessment methodology for the geological disposal of high-level radioactive wastes on the basis of the results from the Phase I program (1987-1993). The Phase II program consisted of following experimental items: (1) radionuclide migration experiments for quarried blocks (1m x 1m x 1m) of granite with natural fracture under in-situ geochemical conditions at 240 m level of Underground Research Laboratory of AECL; (2) study on the effects of dissolved organic materials extracted from natural groundwaters on radionuclide migration; (3) study on groundwater flow using environmental isotopes at two different geologic environments; (4) development of groundwater flow and radionuclide transport model for heterogeneous geological media. The mobility of radionuclides was retarded in the fracture by the deep geological conditions and the fracture paths. The groundwater humic substances with high molecular size were enhanced for the mobility of radionuclides in the sand and granitic media due to the complexation. The application of 36 Cl and 129 I for the analysis on the long-term groundwater flow can be validated on the basis of investigation at the URL site. Moreover, the geostatistical model for the analysis on groundwater flow and radionuclide migration was developed, and was able to describe the groundwater flow and the migration of environmental tracers at AECL sites. This report summaries the results of the Phase II program between JAERI and AECL. (author)

  18. Studies on groundwater flow and radionuclide migration at underground environments. Final report of collaboration research between JAERI and AECL

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Hiromichi; Nagao, Seiya; Yamaguchi, Tetsuji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2001-01-01

    The Japan Atomic Energy Research Institute (JAERI) conducted a collaboration program Phase II with the Atomic Energy of Canada Limited (AECL) from 1994 to 1998. The program was started to contribute the establishment of safety assessment methodology for the geological disposal of high-level radioactive wastes on the basis of the results from the Phase I program (1987-1993). The Phase II program consisted of following experimental items: (1) radionuclide migration experiments for quarried blocks (1m x 1m x 1m) of granite with natural fracture under in-situ geochemical conditions at 240 m level of Underground Research Laboratory of AECL; (2) study on the effects of dissolved organic materials extracted from natural groundwaters on radionuclide migration; (3) study on groundwater flow using environmental isotopes at two different geologic environments; (4) development of groundwater flow and radionuclide transport model for heterogeneous geological media. The mobility of radionuclides was retarded in the fracture by the deep geological conditions and the fracture paths. The groundwater humic substances with high molecular size were enhanced for the mobility of radionuclides in the sand and granitic media due to the complexation. The application of {sup 36}Cl and {sup 129}I for the analysis on the long-term groundwater flow can be validated on the basis of investigation at the URL site. Moreover, the geostatistical model for the analysis on groundwater flow and radionuclide migration was developed, and was able to describe the groundwater flow and the migration of environmental tracers at AECL sites. This report summaries the results of the Phase II program between JAERI and AECL. (author)

  19. Bioremediation of hydrocarbon contaminated surface water, groundwater, and soils

    International Nuclear Information System (INIS)

    Piotrowski, M.R.

    1991-01-01

    Bioremediation is currently receiving considerable attention as a remediation option for sites contaminated with hazardous organic compounds. There is an enormous amount of interest in bioremediation, and numerous journals now publish research articles concerning some aspect of the remediation approach. A review of the literature indicates that two basic forms of bioremediation are currently being practiced: the microbiological approach and the microbial ecology approach. Each form has its advocates and detractors, and the microbiological approach is generally advocated by most of the firms that practice bioremediation. In this paper, the merits and disadvantages of these forms are reviewed and a conceptual approach is presented for assessing which form may be most useful for a particular contaminant situation. I conclude that the microbial ecology form of bioremediation may be the most useful for the majority of contaminant situations, and I will present two case histories in support of this hypothesis

  20. Field sampling for monitoring migration and defining the areal extent of chemical contamination

    International Nuclear Information System (INIS)

    Thomas, J.M.; Skalski, J.R.; Eberhardt, L.L.; Simmons, M.A.

    1984-11-01

    Initial research on compositing, field designs, and site mapping oriented toward detecting spills and migration at commercial low-level radioactive or chemical waste sites is summarized. Results indicate that the significance test developed to detect samples containing high levels of contamination when they are mixed with several other samples below detectable limits (composites), will be highly effective with large sample sizes when contaminant levels frequently or greatly exceed a maximum acceptable level. These conditions of frequent and high contaminant levels are most likely to occur in regions of a commercial waste site where the priors (previous knowledge) about a spill or migration are highest. Conversely, initial investigations of Bayes sampling strategies suggest that field sampling efforts should be inversely proportional to the priors (expressed as probabilities) for the occurrence of contamination

  1. The groundwater contribution to surface water contamination in a region with intensive agricultural land use (Noord-Brabant, The Netherlands)

    International Nuclear Information System (INIS)

    Rozemeijer, J.C.; Broers, H.P.

    2007-01-01

    Traditionally, monitoring of soil, groundwater and surface water quality is coordinated by different authorities in the Netherlands. Nowadays, the European Water Framework Directive (EU, 2000) stimulates an integrated approach of the complete soil-groundwater-surface water system. Based on water quality data from several test catchments, we propose a conceptual model stating that stream water quality at different discharges is the result of different mixing ratios of groundwater from different depths. This concept is used for a regional study of the groundwater contribution to surface water contamination in the Dutch province of Noord-Brabant, using the large amount of available data from the regional monitoring networks. The results show that groundwater is a dominant source of surface water contamination. The poor chemical condition of upper and shallow groundwater leads to exceedance of the quality standards in receiving surface waters, especially during quick flow periods. - Water quality monitoring data show the importance of the groundwater contribution to surface water pollution

  2. Data Assimilation for Management of Industrial Groundwater Contamination at a Regional Scale

    KAUST Repository

    El Gharamti, Mohamad

    2014-12-01

    Groundwater is one of the main sources for drinking water and agricultural activities. Various activities of both humans and nature may lead to groundwater pollution. Very often, pollution, or contamination, of groundwater goes undetected for long periods of time until it begins to a ect human health and/or the environment. Cleanup technologies used to remediate pollution can be costly and remediation processes are often protracted. A more practical and feasible way to manage groundwater contamination is to monitor and predict contamination and act as soon as there is risk to the population and the environment. Predicting groundwater contamination requires advanced numerical models of groundwater ow and solute transport. Such numerical modeling is increasingly becoming a reference criterion for water resources assessment and environmental protection. Subsurface numerical models are, however, subject to many sources of uncertainties from unknown parameters and approximate dynamics. This dissertation considers the sequential data assimilation approach and tackles the groundwater contamination problem at the port of Rotterdam in the Netherlands. Industrial concentration data are used to monitor and predict the fate of organic contaminants using a threedimensional coupled ow and reactive transport model. We propose a number of 5 novel assimilation techniques that address di erent challenges, including prohibitive computational burden, the nonlinearity and coupling of the subsurface dynamics, and the structural and parametric uncertainties. We also investigate the problem of optimal observational designs to optimize the location and the number of wells. The proposed new methods are based on the ensemble Kalman Filter (EnKF), which provides an e cient numerical solution to the Bayesian ltering problem. The dissertation rst investigates in depth the popular joint and dual ltering formulations of the state-parameters estimation problem. New methodologies, algorithmically

  3. Development of one-dimensional computational fluid dynamics code 'GFLOW' for groundwater flow and contaminant transport analysis

    International Nuclear Information System (INIS)

    Rahatgaonkar, P. S.; Datta, D.; Malhotra, P. K.; Ghadge, S. G.

    2012-01-01

    Prediction of groundwater movement and contaminant transport in soil is an important problem in many branches of science and engineering. This includes groundwater hydrology, environmental engineering, soil science, agricultural engineering and also nuclear engineering. Specifically, in nuclear engineering it is applicable in the design of spent fuel storage pools and waste management sites in the nuclear power plants. Ground water modeling involves the simulation of flow and contaminant transport by groundwater flow. In the context of contaminated soil and groundwater system, numerical simulations are typically used to demonstrate compliance with regulatory standard. A one-dimensional Computational Fluid Dynamics code GFLOW had been developed based on the Finite Difference Method for simulating groundwater flow and contaminant transport through saturated and unsaturated soil. The code is validated with the analytical model and the benchmarking cases available in the literature. (authors)

  4. Sustainable mitigation of arsenic contaminated groundwater in Bihar, India

    NARCIS (Netherlands)

    Ghosh, A.; Borges Freitas, S.C.

    2014-01-01

    The “water surplus” state of Bihar is faced with the serious problem of arsenic contaminated aquifers whose water is used both for drinking and irrigation purposes. A large number of mitigation strategies are being adopted by the authorities, without obtaining the desired results of clean water

  5. Both Phosphorus Fertilizers and Indigenous Bacteria Enhance Arsenic Release into Groundwater in Arsenic-Contaminated Aquifers.

    Science.gov (United States)

    Lin, Tzu-Yu; Wei, Chia-Cheng; Huang, Chi-Wei; Chang, Chun-Han; Hsu, Fu-Lan; Liao, Vivian Hsiu-Chuan

    2016-03-23

    Arsenic (As) is a human carcinogen, and arsenic contamination in groundwater is a worldwide public health concern. Arsenic-affected areas are found in many places but are reported mostly in agricultural farmlands, yet the interaction of fertilizers, microorganisms, and arsenic mobilization in arsenic-contaminated aquifers remains uncharacterized. This study investigates the effects of fertilizers and bacteria on the mobilization of arsenic in two arsenic-contaminated aquifers. We performed microcosm experiments using arsenic-contaminated sediments and amended with inorganic nitrogenous or phosphorus fertilizers for 1 and 4 months under aerobic and anaerobic conditions. The results show that microcosms amended with 100 mg/L phosphorus fertilizers (dipotassium phosphate), but not nitrogenous fertilizers (ammonium sulfate), significantly increase aqueous As(III) release in arsenic-contaminated sediments under anaerobic condition. We also show that concentrations of iron, manganese, potassium, sodium, calcium, and magnesium are increased in the aqueous phase and that the addition of dipotassium phosphate causes a further increase in aqueous iron, potassium, and sodium, suggesting that multiple metal elements may take part in the arsenic release process. Furthermore, microbial analysis indicates that the dominant microbial phylum is shifted from α-proteobacteria to β- and γ-proteobacteria when the As(III) is increased and phosphate is added in the aquifer. Our results provide evidence that both phosphorus fertilizers and microorganisms can mediate the release of arsenic to groundwater in arsenic-contaminated sediments under anaerobic condition. Our study suggests that agricultural activity such as the use of fertilizers and monitoring phosphate concentration in groundwater should be taken into consideration for the management of arsenic in groundwater.

  6. Municipal waste management and groundwater contamination processes in Córdoba Province, Argentina

    Directory of Open Access Journals (Sweden)

    Daniel Emilio Martínez

    2010-12-01

    Full Text Available In Coronel Moldes, Argentina, waste management practices consist in municipal waste being tipped directly onto an area of sand dunes at the municipal waste disposal site (MWDS. Moreover, untreated liquid waste from septic tanks and latrines from urban areas are discharged in the same place. This co-disposal waste management is very common in many regions of Argentina and its impact on the groundwater of Coronel Moldes has not been evaluated. The study area is located in the vicinity of a MWDS in a flatlands environment that is typical of Argentina. The main objective of this study was to evaluate the impacts on groundwater quality of current waste management practices in order to consider the requirement for new guidelines for sustainable groundwater management. Three groundwater monitoring wells were installed up-, across- and down-gradient of the MWDS. The principal aquifer is formed by sandy silt sediments (loess. Groundwater levels in the area of the MWDS are between 5.6 m and 7.8 m. The Vulnerability index indicates that groundwater in this area has a high vulnerability. Groundwater in the vicinity of the MWDS shows elevated electrical conductivity, high concentrations of Cl-, Na+, and HCO3- ions, COD, BOD5 and aerobic bacteria and less dissolved oxygen than the background values indicating the presence of organic matter. Municipal waste management represents a significant omission in current groundwater protection policy at Coronel Moldes. Strict supervision of solid and liquid municipal waste disposal needs to be instigated in order to ensure that the groundwater remains free of contamination and to allow a sustainable environmental management.

  7. Particulate Pyrite Autotrophic Denitrification (PPAD) for Remediation of Nitrate-contaminated Groundwater

    Science.gov (United States)

    Tong, S.; Rodriguez-Gonzalez, L. C.; Henderson, M.; Feng, C.; Ergas, S. J.

    2015-12-01

    The rapid movement of human civilization towards urbanization, industrialization, and increased agricultural activities has introduced a large amount of nitrate into groundwater. Nitrate is a toxic substance discharged from groundwater to rivers and leads to decreased dissolved oxygen and eutrophication. For this experiment, an electron donor is needed to convert nitrate into non-toxic nitrogen gas. Pyrite is one of the most abundant minerals in the earth's crust making it an ideal candidate as an electron donor. The overall goal of this research was to investigate the potential for pyrite to be utilized as an electron donor for autotrophic denitrification of nitrate-contaminated groundwater. Batch studies of particulate pyrite autotrophic denitrification (PPAD) of synthetic groundwater (100 mg NO3--N L-1) were set up with varying biomass concentration, pyrite dose, and pyrite particle size. Reactors were seeded with mixed liquor volatile suspended solids (VSS) from a biological nitrogen removal wastewater treatment facility. PPAD using small pyrite particles (exhibited substantial nitrate removal rate, lower sulfate accumulation (5.46 mg SO42-/mg NO3--N) and lower alkalinity consumption (1.70 mg CaCO3/mg NO3--N) when compared to SOD (7.54 mg SO42-/mg NO3--N, 4.57 mg CaCO3/mg NO3--N based on stoichiometric calculation). This research revealed that the PPAD process is a promising technique for nitrate-contaminated groundwater treatment and promoted the utilization of pyrite in the field of environmental remediation.

  8. A report on intercomparison studies of computer programs which respectively model: i) radionuclide migration ii) equilibrium chemistry of groundwater

    International Nuclear Information System (INIS)

    Broyd, T.W.; McD Grant, M.; Cross, J.E.

    1985-01-01

    This report describes two intercomparison studies of computer programs which respectively model: i) radionuclide migration ii) equilibrium chemistry of groundwaters. These studies have been performed by running a series of test cases with each program and comparing the various results obtained. The work forms a part of the CEC MIRAGE project (MIgration of RAdionuclides in the GEosphere) and has been jointly funded by the CEC and the United Kingdom Department of the Environment. Presentations of the material contained herein were given at plenary meetings of the MIRAGE project in Brussels in March, 1984 (migration) and March, 1985 (equilibrium chemistry) respectively

  9. Use of tree-ring chemistry to document historical ground-water contamination events

    Science.gov (United States)

    Vroblesky, Don A.; Yanosky, Thomas M.

    1990-01-01

    The annual growth rings of tulip trees (Liriodendron tulipifera L.) appear to preserve a chemical record of ground-water contamination at a landfill in Maryland. Zones of elevated iron and chlorine concentrations in growth rings from trees immediately downgradient from the landfill are closely correlated temporally with activities in the landfill expected to generate iron and chloride contamination in the ground water. Successively later iron peaks in trees increasingly distant from the landfill along the general direction of ground-water flow imply movement of iron-contaminated ground water away from the landfill. The historical velocity of iron movement (2 to 9 m/yr) and chloride movement (at least 40 m/yr) in ground water at the site was estimated from element-concentration trends of trees at successive distances from the landfill. The tree-ring-derived chloride-transport velocity approximates the known ground-water velocity (30 to 80 m/yr). A minimum horizontal hydraulic conductivity (0.01 to .02 cm/s) calculated from chloride velocity agrees well with values derived from aquifer tests (about 0.07 cm/s) and from ground-water modeling results (0.009 to 0.04 cm/s).

  10. Dissipation of the herbicide oxyfluorfen in subtropical soils and its potential to contaminate groundwater.

    Science.gov (United States)

    Yen, Jui-Hung; Sheu, Wey-Shin; Wang, Yei-Shung

    2003-02-01

    The dissipation and mobility of the herbicide oxyfluorfen (2-chloro-alpha,alpha,alpha-trifluoro-p-tolyl 3-ethoxy-4-nitrophenyl ether) in field soil of Taiwan were investigated in the laboratory with six tea garden soils. The dissipation coefficients of oxyfluorfen in soils of different moisture content (30%, 60%, and 90% of soil field capacity) and soil temperature (10 degrees C, 25 degrees C, and 40 degrees C) were studied. Results indicate that the half-life of oxyfluorfen ranged from 72 to 160 days for six tea garden soils. It was found that if the temperature is high, the dissipation rate is rapid, and there is almost no dissipation at 10 degrees C. Possible contamination of groundwater by the herbicide oxyfluorfen was assessed using the behavior assessment model and the groundwater pollution-potential (GWP) model. The results obtained after evaluating the residue and travel time using the GWP model illustrated that oxyfluorfen is not very mobile in soil and may not contaminate groundwater under normal conditions. But in the case of soil of extremely low organic carbon content and coarse texture, oxyfluorfen has the potential to contaminate groundwater less than 3m deep.

  11. Groundwater isotopic variations in a uranium mining site: subsidies for contamination studies

    International Nuclear Information System (INIS)

    Araujo, V. P. de

    2017-01-01

    The Caetite Experimental Basin (CEB), located in the semi-arid region of Northeastern Brazil, faces not only the challenges associated with water scarcity but also the potential contamination processes due to mining activity. The only active uranium production center in Brazil (URA) is located in this watershed and the sustainability of mining and milling operations, as well as the survival of the local community, is highly dependent on the availability of groundwater resources. This paper analyzes the stable isotopes variation of Deuterium ("2H) and Oxygen-18 ("1"8O) in CEB's groundwater to investigate its dynamics and mixing of water sources as part of initial efforts to characterize the hydrogeology of this area for future contamination and recharge studies. Measurements of δ"2H, δ"1"8O, total dissolved solids (TDS), pH, and electrical conductivity (EC) were carried out in water samples from 27 wells. A total of 98 groundwater samples were analyzed during the dry and wet seasons from 2012 to 2014. All the groundwater samples plotted below the local meteoric line toward more enriched δ"1"8O values, an indicative of evaporation process. "2H and "1"8O data suggests that the main source of groundwater recharge is local precipitation and there is no mixing of infiltrating rainwater with older groundwater. These results provide evidence that the aquifer system in the CEB has a relatively fast turnover time, which contribute to the vulnerability of the aquifer to contamination. These findings are corroborated by the low TDS and EC values indicative of short time in water-rock interaction. (author)

  12. Groundwater isotopic variations in a uranium mining site: subsidies for contamination studies

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, V. P. de [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Divisao de Engenharia Nuclear; Sobrinho, G.A.N.; Freitas, L.D.; Franklin, M.R., E-mail: mariza@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-09-01

    The Caetite Experimental Basin (CEB), located in the semi-arid region of Northeastern Brazil, faces not only the challenges associated with water scarcity but also the potential contamination processes due to mining activity. The only active uranium production center in Brazil (URA) is located in this watershed and the sustainability of mining and milling operations, as well as the survival of the local community, is highly dependent on the availability of groundwater resources. This paper analyzes the stable isotopes variation of Deuterium ({sup 2}H) and Oxygen-18 ({sup 18}O) in CEB's groundwater to investigate its dynamics and mixing of water sources as part of initial efforts to characterize the hydrogeology of this area for future contamination and recharge studies. Measurements of δ{sup 2}H, δ{sup 18}O, total dissolved solids (TDS), pH, and electrical conductivity (EC) were carried out in water samples from 27 wells. A total of 98 groundwater samples were analyzed during the dry and wet seasons from 2012 to 2014. All the groundwater samples plotted below the local meteoric line toward more enriched δ{sup 18}O values, an indicative of evaporation process. {sup 2}H and {sup 18}O data suggests that the main source of groundwater recharge is local precipitation and there is no mixing of infiltrating rainwater with older groundwater. These results provide evidence that the aquifer system in the CEB has a relatively fast turnover time, which contribute to the vulnerability of the aquifer to contamination. These findings are corroborated by the low TDS and EC values indicative of short time in water-rock interaction. (author)

  13. Analysis of the potential contamination risk of groundwater resources circulating in areas with anthropogenic activities

    Directory of Open Access Journals (Sweden)

    M. Spizzico

    2005-01-01

    Full Text Available The area investigated is located in the province of Brindisi (Italy. It is a generally flat area separated from the nearby carbonatic plateau of the Murgia by quite indistinct and high fault scarps. As regards the geological features, carbonatic basement rocks and post-cretaceous terrains made up of calabrian calcarenites and middle-upper Pleistocenic marine terraced deposits can be distinguished. In the examined area there are two different hydrogeological environments. The first is represented by deep groundwater, the main groundwater resource in Apulia. The second hydrogeological environment, now of lesser importance than the deep aquifer in terms of size and use, is made up of some small shallow groundwater systems situated in post-calabrian sands and located in the eastern area. During some sampling cycles carried out in the studied area, water was withdrawn from both the deep aquifer and from the shallow groundwater. For every sample, the necessary parameters were determined for the physical and chemical characterisation of two different hydrogeological environments. Moreover, some chemical parameters indicating anthropogenic activities were determined. Analysis of the aerial distribution of the measured parameters has shown some main areas subject to different conditions of contamination risk, in accordance with the hydrogeological and geological features of the investigated area. In the south-eastern part of the investigated area, the important action performed by the surface aquifer for protecting the deep groundwater from contamination of anthropogenic origin is clear. On the other hand, in the shallow groundwater, areas of nitrate and nitrite contamination have been identified, which result from the extensive use of fertilizers.

  14. Analysis of potential groundwater contamination in the vicinity of the Weldon Spring Raffinate Pits site, Weldon Spring, Missouri

    International Nuclear Information System (INIS)

    Tsai, S.Y.; Peterson, J.M.; Winters, M.C.B.

    1984-08-01

    Results of the analysis of contaminant migration beneath the raffinate pits at the Weldon Spring Raffinate Pits site indicate that during a 10,000-year time period, the maximum concentrations in the water immediately beneath the pit bottoms would be about 4600 pCi/L of radium-226 (Pit 3) and about 12,000 pCi/L of uranium-238 (Pit 1); these concentrations would occur at the centers of the pit bottoms. Based on the assumptions used in this study, the radioactive contaminants in the pits would migrate no more than 2 m (7 ft) below the pit bottoms. Because 6 to 12 m (20 to 40 ft) of silty clays underlie the raffinate pits, the radioactive contaminants would take several tens of thousands of years to reach nearby groundwater supplies. Although the results of these analyses indicate that a high degree of confinement is provided by the four raffinate pits, it should be noted that the validity of such analyses rests on the quality of the parameter values utilized. Due to a lack of current site-specific data for some physical parameters, it has been necessary to use historical and regional data for these values. The values cited are at times inconsistent and contradictory, e.g., the wide range of values indicated for the permeability of clays underlying the pits. However, these were the only data available. The analysis reported herein indicates that within the limitations of the available data, use of the Raffinate Pits site for long-term management of radioactive materials such as those currently being stored in the four pits appears to be feasible. 24 references, 14 figures, 7 tables

  15. Arsenic contamination of groundwater and drinking water in Vietnam: a human health threat.

    Science.gov (United States)

    Berg, M; Tran, H C; Nguyen, T C; Pham, H V; Schertenleib, R; Giger, W

    2001-07-01

    This is the first publication on arsenic contamination of the Red River alluvial tract in the city of Hanoi and in the surrounding rural districts. Due to naturally occurring organic matter in the sediments, the groundwaters are anoxic and rich in iron. With an average arsenic concentration of 159 micrograms/L, the contamination levels varied from 1 to 3050 micrograms/L in rural groundwater samples from private small-scale tubewells. In a highly affected rural area, the groundwater used directly as drinking water had an average concentration of 430 micrograms/L. Analysis of raw groundwater pumped from the lower aquifer for the Hanoi water supply yielded arsenic levels of 240-320 micrograms/L in three of eight treatment plants and 37-82 micrograms/L in another five plants. Aeration and sand filtration that are applied in the treatment plants for iron removal lowered the arsenic concentrations to levels of 25-91 micrograms/L, but 50% remained above the Vietnamese Standard of 50 micrograms/L. Extracts of sediment samples from five bore cores showed a correlation of arsenic and iron contents (r2 = 0.700, n = 64). The arsenic in the sediments may be associated with iron oxyhydroxides and released to the groundwater by reductive dissolution of iron. Oxidation of sulfide phases could also release arsenic to the groundwater, but sulfur concentrations in sediments were below 1 mg/g. The high arsenic concentrations found in the tubewells (48% above 50 micrograms/L and 20% above 150 micrograms/L) indicate that several million people consuming untreated groundwater might be at a considerable risk of chronic arsenic poisoning.

  16. In situ treatment of cyanide-contaminated groundwater by iron cyanide precipitation

    International Nuclear Information System (INIS)

    Ghosh, R.S.; Dzombak, D.A.; Luthy, R.G.; Smith, J.R.

    1999-01-01

    Groundwater contamination with cyanide is common at many former or active industrial sites. Metal-cyanide complexes typically dominate aqueous speciation of cyanide in groundwater systems, with iron-cyanide complexes often most abundant. Typically, metal-cyanide complexes behave as nonadsorbing solutes in sand-gravel aquifer systems in the neutral pH range, rendering cyanide relatively mobile in groundwater systems. Groundwater pump-and-treat systems have often been used to manage cyanide contamination in groundwater. This study examined the feasibility of using in situ precipitation of iron cyanide in a reactive barrier to attenuate the movement of cyanide in groundwater. Laboratory column experiments were performed in which cyanide solutions were passed through mixtures of sand and elemental iron filings. Removal of dissolved cyanide was evaluated in a variety of cyanide-containing influents under various flow rates and sand-to-iron weight ratios. Long-term column tests performed with various cyanide-containing influents under both oxic and anoxic conditions, at neutral pH and at flow rates typical of sand-gravel porous media, yielded effluent concentrations of total cyanide as low as 0.5 mg/L. Effluent cyanide concentrations achieved were close to the solubilities of Turnbull's blue-hydrous ferric oxide solid solutions, indicating co-precipitation of the two solids. Maximum cyanide removal efficiency was achieved with approximately 10% by weight of iron in the sand-iron mixtures; higher iron contents did not increase removal efficiency significantly. Results obtained indicate that in situ precipitation is a promising passive treatment approach for cyanide in groundwater

  17. Baseline risk assessment of groundwater contamination at the uranium mill tailings site near Shiprock, New Mexico. Draft

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    This report evaluates potential impact to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1986 by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This risk assessment is the first document specific to this site for the Groundwater Project. This risk assessment follows the approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the floodplain groundwater are arsenic, magnesium, manganese, nitrate, sodium, sulfate, and uranium. The complete list of contaminants associated with the terrace groundwater could not be determined due to the lack of the background groundwater quality data. However, uranium, nitrate, and sulfate are evaluated since these chemicals are clearly associated with uranium processing and are highly elevated compared to regional waters. It also could not be determined if the groundwater occurring in the terrace is a usable water resource, since it appears to have originated largely from past milling operations. The next step in the risk assessment is to estimate how much of these contaminants people would be exposed to if a drinking well were installed in the contaminated groundwater or if there were exposure to surface expressions of contaminated water. Potential exposures to surface water include incidental contact with contaminated water or sediments by children playing on the floodplain and consumption of meat and milk from domestic animals grazed and watered on the floodplain.

  18. Assessment of Groundwater Susceptibility to Non-Point Source Contaminants Using Three-Dimensional Transient Indexes.

    Science.gov (United States)

    Zhang, Yong; Weissmann, Gary S; Fogg, Graham E; Lu, Bingqing; Sun, HongGuang; Zheng, Chunmiao

    2018-06-05

    Groundwater susceptibility to non-point source contamination is typically quantified by stable indexes, while groundwater quality evolution (or deterioration globally) can be a long-term process that may last for decades and exhibit strong temporal variations. This study proposes a three-dimensional (3- d ), transient index map built upon physical models to characterize the complete temporal evolution of deep aquifer susceptibility. For illustration purposes, the previous travel time probability density (BTTPD) approach is extended to assess the 3- d deep groundwater susceptibility to non-point source contamination within a sequence stratigraphic framework observed in the Kings River fluvial fan (KRFF) aquifer. The BTTPD, which represents complete age distributions underlying a single groundwater sample in a regional-scale aquifer, is used as a quantitative, transient measure of aquifer susceptibility. The resultant 3- d imaging of susceptibility using the simulated BTTPDs in KRFF reveals the strong influence of regional-scale heterogeneity on susceptibility. The regional-scale incised-valley fill deposits increase the susceptibility of aquifers by enhancing rapid downward solute movement and displaying relatively narrow and young age distributions. In contrast, the regional-scale sequence-boundary paleosols within the open-fan deposits "protect" deep aquifers by slowing downward solute movement and displaying a relatively broad and old age distribution. Further comparison of the simulated susceptibility index maps to known contaminant distributions shows that these maps are generally consistent with the high concentration and quick evolution of 1,2-dibromo-3-chloropropane (DBCP) in groundwater around the incised-valley fill since the 1970s'. This application demonstrates that the BTTPDs can be used as quantitative and transient measures of deep aquifer susceptibility to non-point source contamination.

  19. Discussion on 'Solar detoxification of fuel-contaminated groundwater using fixed-bed photocatalysts'

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, Joseph B.

    1997-03-15

    In a discussion of the 1997 paper by J. C. Crittenden et al. on the solar detoxification of fuel-contaminated groundwater using fixed-bed photocatalysts, the writer indicates a number of problems with the interpretation of the data and invites the authors to speculate on the reaction mechanism in the photocatalytic destruction of BTEX compounds in groundwater. In reply, Crittenden points out that it is not easy to speculate on the reaction mechanism because there are many compounds other than BTEX compounds contained in the water matrix, as well as many unknown compounds and by-products.

  20. The application of illite supported nanoscale zero valent iron for the treatment of uranium contaminated groundwater.

    Science.gov (United States)

    Jing, C; Landsberger, S; Li, Y L

    2017-09-01

    In this study, nanoscale zero valent iron I-NZVI was investigated as a remediation strategy for uranium contaminated groundwater from the former Cimarron Fuel Fabrication Site in Oklahoma, USA. The 1 L batch-treatment system was applied in the study. The result shows that 99.9% of uranium in groundwater was removed by I-NZVI within 2 h. Uranium concentration in the groundwater stayed around 27 μg/L, and there was no sign of uranium release into groundwater after seven days of reaction time. Meanwhile the release of iron was significantly decreased compared to NZVI which can reduce the treatment impact on the water environment. To study the influence of background pH of the treatment system on removal efficiency of uranium, the groundwater was adjusted from pH 2-10 before the addition of I-NZVI. The pH of the groundwater was from 2.1 to 10.7 after treatment. The removal efficiency of uranium achieved a maximum in neutral pH of groundwater. The desorption of uranium on the residual solid phase after treatment was investigated in order to discuss the stability of uranium on residual solids. After 2 h of leaching, 0.07% of the total uranium on residual solid phase was leached out in a HNO 3 leaching solution with a pH of 4.03. The concentration of uranium in the acid leachate was under 3.2 μg/L which is below the EPA's maximum contaminant level of 30 μg/L. Otherwise, the concentration of uranium was negligible in distilled water leaching solution (pH = 6.44) and NaOH leaching solution (pH = 8.52). A desorption study shows that an acceptable amount of uranium on the residuals can be released into water system under strong acid conditions in short terms. For long term disposal management of the residual solids, the leachate needs to be monitored and treated before discharge into a hazardous landfill or the water system. For the first time, I-NZVI was applied for the treatment of uranium contaminated groundwater. These results provide proof that I-NZVI has

  1. Cometabolic biotreatment of TCE-contaminated groundwater: Laboratory and bench-scale development studies

    International Nuclear Information System (INIS)

    Donaldson, T.L.; Jennings, H.L.; Lucero, A.J.; Strandberg, G.W.; Morris, M.I.; Palumbo, A.V.; Boerman, P.A.; Tyndall, R.L.

    1992-01-01

    The Oak Ridge National Laboratory is conducting a demonstration of two cometabolic technologies for biotreatment of groundwater contaminated with trichloroethylene (TCE) and other organics. Technologies based on methanotrophic (methane-utilizing) and toluene-degrading microorganisms will be compared side-by-side on the same groundwater stream. Laboratory and bench-scale bioreactor studies have been conducted to guide selection of microbial cultures and operating conditions for the field demonstration. This report presents the results of the laboratory and bench-scale studies for the methanotrophic system

  2. Metropol: A computer code for the simulation of transport of contaminants with groundwater

    International Nuclear Information System (INIS)

    Sauter, F.J.; Hassanizadeh, S.M.; Leijnse, A.; Glasbergen, P.; Slot, A.F.M.

    1990-01-01

    In this report a description is given of the computer code Metropol. This code simulates the three-dimensional flow of groundwater with varying density and the simultaneous transport of contaminants in low concentration and is based on the finite element method. The basic equations for groundwater flow and transport are described as well as the mathematical techniques used to solve these equations. Pre-processing facilities for mesh generation and post-processing facilities such as particle tracking are also discussed. This work was part of the Community Mirage project Second phase, research area Calculation tools

  3. Cometabolic biotreatment of TCE-contaminated groundwater - Laboratory and bench-scale development studies

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, T L; Palumbo, A V; Boerman, P A; Jennings, H L; Lucero, A J; Tyndall, R L; Strandberg, G W; Morris, M I [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1992-07-01

    The Oak Ridge National Laboratory is conducting a demonstration of two cometabolic technologies for biotreatment of groundwater contaminated with trichloroethylene (TCE) and other organics. Technologies based on methanotrophic (methane-utilizing) and toluene-degrading microorganisms will be compared side-by-side on the same groundwater stream. Laboratory and bench-scale bioreactor studies have been conducted to guide selection of microbial cultures and operating conditions for the field demonstration. This report presents the results of the laboratory and bench-scale studies for the methanotrophic system. (author)

  4. Modelling the fate of oxidisable organic contaminants in groundwater

    DEFF Research Database (Denmark)

    Barry, D.A.; Prommer, H.; Miller, C.T.

    2002-01-01

    modelling framework is illustrated by pertinent examples, showing the degradation of dissolved organics by microbial activity limited by the availability of nutrients or electron acceptors (i.e., changing redox states), as well as concomitant secondary reactions. Two field-scale modelling examples......Subsurface contamination by organic chemicals is a pervasive environmental problem, susceptible to remediation by natural or enhanced attenuation approaches or more highly engineered methods such as pump-and-treat, amongst others. Such remediation approaches, along with risk assessment...... are discussed, the Vejen landfill (Denmark) and an example where metal contamination is remediated by redox changes wrought by injection of a dissolved organic compound. A summary is provided of current and likely future challenges to modelling of oxidisable organics in the subsurface. (C) 2002 Elsevier Science...

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

    Science.gov (United States)

    Lorah, Michelle M.; Clark, Jeffrey S.

    1996-01-01

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

  6. Persistent and emerging micro-organic contaminants in Chalk groundwater of England and France

    International Nuclear Information System (INIS)

    Lapworth, D.J.; Baran, N.; Stuart, M.E.; Manamsa, K.; Talbot, J.

    2015-01-01

    The Chalk aquifer of Northern Europe is an internationally important source of drinking water and sustains baseflow for surface water ecosystems. The areal distribution of microorganic (MO) contaminants, particularly non-regulated emerging MOs, in this aquifer is poorly understood. This study presents results from a reconnaissance survey of MOs in Chalk groundwater, including pharmaceuticals, personal care products and pesticides and their transformation products, conducted across the major Chalk aquifers of England and France. Data from a total of 345 sites collected during 2011 were included in this study to provide a representative baseline assessment of MO occurrence in groundwater. A suite of 42 MOs were analysed for at each site including industrial compounds (n = 16), pesticides (n = 14) and pharmaceuticals, personal care and lifestyle products (n = 12). Occurrence data is evaluated in relation to land use, aquifer exposure, well depth and depth to groundwater to provide an understanding of vulnerable groundwater settings. - Highlights: • Broad range of microorganics detected in Chalk groundwater in England and France. • Plasticisers, pesticides, BPA and THM detected at the highest concentrations. • Pesticides higher in outcrop Chalk, caffeine and BPA at concealed sites. • Occurrences show some relationship to land use, borehole depth and water level. - Broad screening reveals for the first time the extent of emerging microorganic pollution in Chalk groundwater sources across England and France

  7. Contamination valuation of soil and groundwater source at anaerobic municipal solid waste landfill site.

    Science.gov (United States)

    Aziz, Shuokr Qarani; Maulood, Yousif Ismael

    2015-12-01

    The present work aimed to determine the risks that formed landfill leachate from anaerobic Erbil Landfill Site (ELS) poses on groundwater source and to observe the effects of disposed municipal solid waste (MSW) on soil properties. The study further aims to fill the gap in studies on the effects of disposed MSW and produced leachate on the groundwater characteristics and soil quality at ELS, Iraq. Soil, leachate, and groundwater samples were collected from ELS for use as samples in this study. Unpolluted groundwater samples were collected from an area outside of the landfill. Field and laboratory experiments for the soil samples were conducted. Chemical analyses for the soil samples such as organic matter, total salts, and SO4 (=) were also performed. Raw leachate and groundwater samples were analyzed using physical and chemical experiments. The yields for sorptivity, steady-state infiltration rate, and hydraulic conductivity of the soil samples were 0.0006 m/√s, 0.00004 m/s, and 2.17 × 10(-5) m/s, respectively. The soil at ELS was found to be light brown clayey gravel with sand and light brown gravely lean clay layers with low permeability. Unprocessed leachate analysis identified the leachate as stabilized. Findings showed that the soil and groundwater at the anaerobic ELS were contaminated.

  8. Evaluating Contaminant Flux from the Vadose Zone to the Groundwater in the Hanford Central Plateau. SX Tank Farms Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-01

    At the DOE Hanford Site, contaminants were discharged to the subsurface through engineered waste sites in the Hanford Central Plateau. Additional waste was released through waste storage tank leaks. Much of the contaminant inventory is still present within the unsaturated vadose zone sediments. The nature and extent of future groundwater contaminant plumes and the growth or decline of current groundwater plumes beneath the Hanford Central Plateau are a function of the contaminant flux from the vadose zone to the groundwater. In general, contaminant transport is slow through the vadose zone and it is difficult to directly measure contaminant flux in the vadose zone. Predictive analysis, supported by site characterization and monitoring data, was applied using a structured, systems-based approach to estimate the future contaminant flux to groundwater in support of remediation decisions for the vadose zone and groundwater (Truex and Carroll 2013). The SX Tank Farm was used as a case study because of the existing contaminant inventory in the vadose zone, observations of elevated moisture content in portions of the vadose zone, presence of a limited-extent groundwater plume, and the relatively large amount and wide variety of data available for the site. Although the SX Tank Farm case study is most representative of conditions at tank farm sites, the study has elements that are also relevant to other types of disposal sites in the Hanford Central Plateau.

  9. Identifying sources of groundwater nitrate contamination in a large alluvial groundwater basin with highly diversified intensive agricultural production

    Science.gov (United States)

    Lockhart, K. M.; King, A. M.; Harter, T.

    2013-08-01

    Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. The San Joaquin Valley, California, is an example of an agricultural landscape with a large diversity of field, vegetable, tree, nut, and citrus crops, but also confined animal feeding operations (CAFOs, here mostly dairies) that generate, store, and land apply large amounts of liquid manure. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤ 150 m deep), of which many have been affected by nitrate. Variability in crops, soil type, and depth to groundwater contribute to large variability in nitrate occurrence across the underlying aquifer system. The role of these factors in controlling groundwater nitrate contamination levels is examined. Two hundred domestic wells were sampled in two sub-regions of the San Joaquin Valley, Stanislaus and Merced (Stan/Mer) and Tulare and Kings (Tul/Kings) Counties. Forty six percent of well water samples in Tul/Kings and 42% of well water samples in Stan/Mer exceeded the MCL for nitrate (10 mg/L NO3-N). For statistical analysis of nitrate contamination, 78 crop and landuse types were considered by grouping them into ten categories (CAFO, citrus, deciduous fruits and nuts, field crops, forage, native, pasture, truck crops, urban, and vineyards). Vadose zone thickness, soil type, well construction information, well proximity to dairies, and dominant landuse near the well were considered. In the Stan/Mer area, elevated nitrate levels in domestic wells most strongly correlate with the combination of very shallow (≤ 21 m) water table and the presence of either CAFO derived animal waste applications or deciduous fruit and nut crops (synthetic fertilizer applications). In Tulare County, statistical data indicate that elevated

  10. Mobilization of arsenic and other naturally occurring contaminants in groundwater of the Main Ethiopian Rift aquifers.

    Science.gov (United States)

    Rango, Tewodros; Vengosh, Avner; Dwyer, Gary; Bianchini, Gianluca

    2013-10-01

    This study investigates the mechanisms of arsenic (As) and other naturally occurring contaminants (F(-), U, V, B, and Mo) mobilization from Quaternary sedimentary aquifers of the Main Ethiopian Rift (MER) and their enrichment in the local groundwater. The study is based on systematic measurements of major and trace elements as well as stable oxygen and hydrogen isotopes in groundwater, coupled with geochemical and mineralogical analyses of the aquifer rocks. The Rift Valley aquifer is composed of rhyolitic volcanics and Quaternary lacustrine sediments. X-ray fluorescence (XRF) results revealed that MER rhyolites (ash, tuff, pumice and ignimbrite) and sediments contain on average 72 wt. % and 65 wt. % SiO2, respectively. Petrographic studies of the rhyolites indicate predominance of volcanic glass, sanidine, pyroxene, Fe-oxides and plagioclase. The As content in the lacustrine sediments (mean = 6.6 mg/kg) was higher than that of the rhyolites (mean: 2.5 mg/kg). The lacustrine aquifers of the Ziway-Shala basin in the northern part of MER were identified as high As risk zones, where mean As concentration in groundwater was 22.4 ± 33.5 (range of 0.60-190 μg/L) and 54% of samples had As above the WHO drinking water guideline value of 10 μg/L. Field As speciation measurements showed that most of the groundwater samples contain predominantly (~80%) arsenate-As(V) over arsenite-As(III) species. The As speciation together with field data of redox potential (mean Eh = +73 ± 65 mV) and dissolved-O2 (6.6 ± 2.2 mg/L) suggest that the aquifer is predominantly oxidative. Water-rock interactions, including the dissolution of volcanic glass produces groundwater with near-neutral to alkaline pH (range 6.9-8.9), predominance of Na-HCO3 ions, and high concentration of SiO2 (mean: 85.8 ± 11.3 mg/L). The groundwater data show high positive correlation of As with Na, HCO3, U, B, V, and Mo (R(2) > 0.5; p groundwater indicates that Fe-oxides and oxyhydroxides minerals were saturated

  11. Sources of nitrate and ammonium contamination in groundwater under developing Asian megacities

    International Nuclear Information System (INIS)

    Umezawa, Yu; Hosono, Takahiro; Onodera, Shin-ichi; Siringan, Fernando; Buapeng, Somkid; Delinom, Robert; Yoshimizu, Chikage; Tayasu, Ichiro; Nagata, Toshi; Taniguchi, Makoto

    2008-01-01

    The status of nitrate (NO 3 - ), nitrite (NO 2 - ) and ammonium (NH 4 + ) contamination in the water systems, and the mechanisms controlling their sources, pathways, and distributions were investigated for the Southeast Asian cities of Metro Manila, Bangkok, and Jakarta. GIS-based monitoring and dual isotope approach (nitrate δ 15 N and δ 18 O) suggested that human waste via severe sewer leakage was the major source of nutrient contaminants in Metro Manila and Jakarta urban areas. Furthermore, the characteristics of the nutrient contamination differed depending on the agricultural land use pattern in the suburban areas: high nitrate contamination was observed in Jakarta (dry fields), and relatively lower nutrients consisting mainly of ammonium were detected in Bangkok (paddy fields). The exponential increase in NO 3 - -δ 15 N along with the NO 3 - reduction and clear δ 18 O/δ 15 N slopes of NO 3 - (∼ 0.5) indicated the occurrence of denitrification. An anoxic subsurface system associated with the natural geological setting (e.g., the old tidal plain at Bangkok) and artificial pavement coverage served to buffer NO 3 - contamination via active denitrification and reduced nitrification. Our results showed that NO 3 - and NH 4 + contamination of the aquifers in Metro Manila, Bangkok, and Jakarta was not excessive, suggesting low risk of drinking groundwater to human health, at present. However, the increased nitrogen load and increased per capita gross domestic product (GDP) in these developing cities may increase this contamination in the very near future. Continuous monitoring and management of the groundwater system is needed to minimize groundwater pollution in these areas, and this information should be shared among adjacent countries with similar geographic and cultural settings

  12. Groundwater-derived contaminant fluxes along a channelized Coastal Plain stream

    Energy Technology Data Exchange (ETDEWEB)

    LaSage, Danita m [JL Sexton and Son; Fryar, Alan E [Dept of Earth and Geoligical Sciences, Univ of KY,; Mukherjee, Abhijit [Univ of Tx, Jackson School of Geosciences, Bur of Econ. Geology; Sturchio, Neil C [Dept of earth and Env. Sciences, Univ of Ill at Chicago; Heraty, Linnea J [Dept of earth and Env. Sciences, Univ of Ill at Chicago

    2008-10-01

    Recent studies in various settings across eastern North America have examined the movement of volatile organic compound (VOC) plumes from groundwater to streams, but few studies have addressed focused discharge of such plumes in unlithified sediments. From 1999 through 2002, we monitored concentrations of trichloroethene (TCE) and the non-volatile co-contaminant technetium-99 along Little Bayou Creek, a first -order perennial stream in the Coastal Plain of western Kentucky. Spring flow contributed TCE and technetium-99 to the creek, and TCE concentrations tended to vary with technetium-99 in springs. Contaminant concentrations in stream water fluctuated seasonally, but not always synchronously with stream flow. However, contaminant influxes varied seasonally with stream flow and were dominated by a few springs. Concentrations of O2, NO3⁻, and SO2-4, values of δ37CL in groundwater, and the lack of less-chlorinated ethenes in groundwater and stream water indicated that aerobic biodegradation of TCE was unlikely. Losses of TCE along Little Bayou Creek resulted mainly from volatilization, in contrast to streams receiving diffuse contaminated discharge, where intrinsic bioremediation of VOCs appears to be prevalent.

  13. Baseline risk assessment for groundwater contamination at the uranium mill tailings site, Gunnison, Colorado

    International Nuclear Information System (INIS)

    1990-11-01

    The Gunnison Baseline Risk Assessment for Groundwater Contamination at the Uranium Mill Tailings Site was performed to determine if long-term use of groundwater from domestic wells near the site has a potential for adverse health effects. The risk assessment was based on the results of sampling domestic wells during 1989--1990. A risk assessment evaluates health risks by comparing the amount of a contaminant taken in by a person with the amount of the contaminant that may be toxic. The Gunnison Risk Assessment used high intake values to estimate the maximum levels a person might be exposed to. The results of the risk assessment are divided into cancer (carcinogenic) risks and non-carcinogenic risks. Five key contaminants were evaluated for adverse health risks: uranium, manganese, lead antimony, and cadmium. Due to the potential health risks and the unavoidable uncertainties associated with limited groundwater and toxicity data, it is prudent public health policy to provide a permanent alternate water supply. Additionally, providing a permanent alternate water supply is cost-effective compared to long-term routine monitoring

  14. The field application of an immunoassay-based test for petroleum fuels contamination in groundwater

    International Nuclear Information System (INIS)

    Carter, K.R.

    1994-01-01

    The recent development of low-cost, rapid field analytical tests for petroleum fuels based on immunoassay technology has provided an on-site tool for the cost-effective, accurate assessment of groundwater contamination. The method allows for rapid, direct measurement of contaminant concentration. The method has been used for a variety of applications including surface water runoff testing and groundwater monitoring well siting. The PETRO RISc Water Test can be used to substantially reduce the cost of monitoring well installation. Current, monitoring wells are placed based on knowledge of the location of the source of contamination, the size of the release, the time elapsed since the release began, and the hydrogeology of the site. While the location of the source is generally known with some precision, the hydrogeology of the site and the timing of the release rarely are. This results in the need for an ''educated guess'' regarding the drilling location for monitoring wells that are installed to provide long term feedback on groundwater contamination. The tests have the greatest sensitivity to aliphatic compounds in the range of six to ten carbons and aromatic compounds such as toluene, xylene, and naphthalene

  15. The use of sparge curtains for contaminant plume control

    International Nuclear Information System (INIS)

    Molnaa, B.; Dablow, J.

    1994-01-01

    Contamination by petroleum hydrocarbons and organic solvents represents a major impact to soil and groundwater. Following recent research and development, several technologies have evolved to treat saturated zone adsorbed- and dissolved-phase contaminants in situ. These technologies include bioremediation and air sparging. Funnel and gate approaches have been developed at the Waterloo Center for Groundwater Research to control contaminant plume migration and treat dissolved-phase contaminants before allowing migration downgradient and off site. The process consists of using low hydraulic conductivity cutoff walls to funnel groundwater flow through gates that contain in situ bioreactors. These systems can maintain hydraulic control and treat dissolved-phase contaminants at the downgradient margins of plumes, while minimizing, or in some cases eliminating, the need for groundwater pumping. Sparge curtains can be applied to treat dissolved-phase contaminants and prevent downgradient, off-site migration of contaminated groundwater

  16. Emerging organic contaminants in surface water and groundwater: a first overview of the situation in Italy.

    Science.gov (United States)

    Meffe, Raffaella; de Bustamante, Irene

    2014-05-15

    This paper provides the first review of the occurrence of 161 emerging organic compounds (EOCs) in Italian surface water and groundwater. The reported EOCs belong to the groups of industrials, pharmaceuticals, estrogens and illicit drugs. Occurrence of 137 pesticides was also reported. The reviewed research works have been published between 1997 and 2013. The majority of the studies have been carried out in Northern Italy (n. 30) and to a lower extent in Central Italy (n. 13). Only a limited number of research studies report EOC concentrations in water resources of Southern Italy. The EOCs that have been more frequently studied are in the following descending order, pesticides (16), pharmaceuticals (15), industrials (13), estrogens (7) and illicit drugs (2). Research activities investigating the EOC occurrence in surface water are more numerous than those in groundwater. This is consistent with the higher complexity involved in groundwater sampling and EOC detection. Among the reported EOCs, industrials and pesticides are those occurring in both surface water and groundwater with the highest concentrations (up to 15 × 10(6) and 4.78 × 0(5)ng L(-1), respectively). Concentrations of pharmaceuticals in surface water reach a maximum of 3.59 × 10(3)ng L(-1), whereas only the antimicrobial agent josamycin has been encountered in groundwater with a concentration higher than 100 ng L(-1). Both estrogens and illicit drugs appeared in surface water with concentrations lower than 50 ng L(-1). Groundwater concentrations for estrogens were measured to be below the detection limits, whereas illicit drugs have so far not been studied in groundwater. The present review reveals the serious contamination status of Italian surface water and groundwater especially by pesticides, industrials and to a lower extent by pharmaceuticals and the necessity to foster the research on EOC occurrence in Italian water resources, in particular in Southern Italy where a limited number of

  17. Dug Well Recharge Method for Insitu Mitigation of Fluoride Contamination in Groundwater

    Science.gov (United States)

    Ganesan, G.; Lakshmanan, E.; Gunalan, J.

    2016-12-01

    Groundwater with fluoride concentration exceeding 1.5 mg/l is not suitable for drinking water supply as it may cause health issues such as dental and skeletal fluorosis to humans. Several million people around the world has been affected by fluorosis. The objective of the study is to mitigate the problem of fluoride contamination in groundwater by increasing groundwater recharge through a dug well recharge system. The study was carried out in a part of Vaniyar river basin, northwest Tamil Nadu, India where fluorosis is prevalent. A cylindrical pit of 1m diameter and 1.5 m height was constructed during May 2014 at a distance of about 4 m from a dug well existing in this area. This cylindrical pit was divided into 3 compartments and one of them was filled with gravel and one with sand. The third compartment was kept empty for inspection and maintenance. The rainfall collected in a funnel shaped depression was allowed to pass through these compartments to discharge in the nearby dug well through a pipe. The concentration of the fluoride in groundwater from this well was had been monitoring on bi-monthly basis from the year 2012 to 2014. After construction of dug well recharge system, the groundwater level has raised by about 5 m and the fluoride concentration has decreased from 3.1 mg/l to 1.44 mg/l due to recharge. The concentration of fluoride and groundwater level is being monitored on daily basis from June 2014. It is evident that the recharge system constructed is working well and the concentration of fluoride in groundwater is within the permissible limit. The advantage of this dug well recharge system is its low cost and the ease of implementation. Thus this pilot study on dug well recharge system demonstrated it's potential in reducing the concentration of fluoride in groundwater which is more beneficial to the society as they cannot afford the well proven water treatment methods.

  18. Groundwater Contamination by Uranium and Mercury at the Ridaura Aquifer (Girona, NE Spain

    Directory of Open Access Journals (Sweden)

    Andrés Navarro

    2016-08-01

    Full Text Available Elevated concentrations of uranium and mercury have been detected in drinking water from public supply and agricultural wells in alluvial and granitic aquifers of the Ridaura basin located at Catalan Coastal Ranges (CCR. The samples showed high concentrations of U above the U.S. standards and the World Health Organization regulations which set a maximum value of 30 µg/L. Further, high mercury concentrations above the European Drinking Water Standards (1 μg/L were found. Spatial distribution of U in groundwater and geochemical evolution of groundwater suggest that U levels appear to be highest in granitic areas where groundwater has long residence times and a significant salinity. The presence of high U concentrations in alluvial groundwater samples could be associated with hydraulic connection through fractures between the alluvial system and deep granite system. According to this model, oxidizing groundwater moving through fractures in the leucocratic/biotitic granite containing anomalous U contents are the most likely to acquire high levels of U. The distribution of Hg showed concentrations above 1 μg/L in 10 alluvial samples, mainly located near the limit of alluvial aquifer with igneous rocks, which suggests a possible migration of Hg from granitic materials. Also, some samples showed Hg concentrations comprised between 0.9 and 1.5 μg/L, from wells located in agricultural areas.

  19. Hydrogeological modelling for migration of radioactivity

    International Nuclear Information System (INIS)

    Sunny, Faby; Chopra, Manish; Oza, R.B.

    2016-01-01

    The hydrogeological modelling for migration of radionuclides basically involves modelling of groundwater flow and contaminant transport through the groundwater. The water that occurs below the land surface or within the lithosphere is called groundwater. The groundwater constitutes about 4 % of the total water on the earth and about 30 % of freshwater on the earth. Groundwater models describe groundwater flow and contaminant transport processes using mathematical equations that are based on certain simplifying assumptions. These assumptions typically involve the direction of flow, geometry of the aquifer, the heterogeneity or anisotropy of sediments or bedrock within the aquifer, the contaminant transport mechanisms and chemical reactions. Because of the simplifying assumptions and the many uncertainties in the values of data, a model must be viewed as an approximation and not an exact duplication of field conditions. However, these models are useful investigation tool for a number of applications such as prediction of the possible fate and migration of contaminants for risk evaluation; tracking the possible pathway of groundwater contamination; evaluation of design of hydraulic containment and pump-and-treat systems; design of groundwater monitoring networks; evaluation of regional groundwater resources and prediction of the effect of future groundwater withdrawals on groundwater levels

  20. Electrochemical migration in electronics: effect of contamination and bias conditions

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    A number of reliability issues are caused by mechanisms different from the conventional corrosion due to specific aspects of the printed circuit board assembly (PCBA). The size of the components and the distance between them, combinations of dissimilar metals, voltage and temperature gradients...... – all together influence susceptibility of electronic PCBA to corrosion. When electronics is operating under humid conditions, the cleanliness of the PCBA becomes essential, since corrosion related failures in electronics can occur at extremely low levels of moisture and contamination. A synergetic...... effect of the aspects mentioned above makes it challenging to predict the lifetime of electronic device. The aim of this work is to investigate corrosion influencing factors, which at a later stage improve capabilities of predicting the functioning and herewith reliability of electronics under certain...

  1. Modelling of flow and contaminant migration in single rock fractures

    International Nuclear Information System (INIS)

    Dahlblom, P.; Joensson, L.

    1990-03-01

    The report deals with flow and hydrodynamic dispersion of a nonreactive contaminant in a single, irregularly shaped fracture. The main purpose of the report is to describe the basis and development of a computational 'tool' for simulating the aperture geometry of a single fracture and the detailed flow in it. On the basis of this flow information further properties of the fracture can be studied. Some initial application to dispersion of a nonreactive contaminant are thus discussed. The spatial pattern of variation of the fracture aperture is considered as a two-dimensional stochastic process. A method for simulation of such a process is described. The stochastic properties can be chosen arbitrarily. It is assumed that the fracture aperture belongs to a log-normal distribution. For calculation of the flow pattern, the Navier-Stokes equations are simplified to describe low velocity and steady-state flow. These equations, and the continuity equation are integrated in the direction across the fracture plane. A stream function, which describes the integrated flow in the fracture, is defined. A second order partial differential equation, with respect to the stream function, is established and solved by the finite difference method. Isolines for the stream function define boundaries between channels with equal flow rates. The travel time for each channel can be calculated to achieve a measure of the dispersion. The impact of the aperture distribution on the ratio between the mass balance fracture aperture and the cubic law fracture aperture is shown by simple examples. (28 figs., 1 tab., 22 refs.)

  2. Assessing soil and groundwater contamination from biofuel spills.

    Science.gov (United States)

    Chen, Colin S; Shu, Youn-Yuen; Wu, Suh-Huey; Tien, Chien-Jung

    2015-03-01

    Future modifications of fuels should include evaluation of the proposed constituents for their potential to damage environmental resources such as the subsurface environment. Batch and column experiments were designed to simulate biofuel spills in the subsurface environment and to evaluate the sorption and desorption behavior of target fuel constituents (i.e., monoaromatic and polyaromatic hydrocarbons) in soil. The extent and reversibility of the sorption of aromatic biofuel constituents onto soil were determined. When the ethanol content in ethanol-blended gasoline exceeded 25%, enhanced desorption of the aromatic constituents to water was observed. However, when biodiesel was added to diesel fuel, the sorption of target compounds was not affected. In addition, when the organic carbon content of the soil was higher, the desorption of target compounds into water was lower. The empirical relationships between the organic-carbon normalized sorption coefficient (Koc) and water solubility and between Koc and the octanol-water partition coefficient (Kow) were established. Column experiments were carried out for the comparison of column effluent concentration/mass from biofuel-contaminated soil. The dissolution of target components depended on chemical properties such as the hydrophobicity and total mass of biofuel. This study provides a basis for predicting the fate and transport of hydrophobic organic compounds in the event of a biofuel spill. The spill scenarios generated can assist in the assessment of biofuel-contaminated sites.

  3. Agricultural contamination in soil-groundwater-surface water systems in the North China Plain

    DEFF Research Database (Denmark)

    Brauns, Bentje

    of fertilizers and pesticides. Unfortunately, the lack of regulation or oversight has led to the overuse of these agrochemicals: current application rates (in kg/ha) are two- to threefold higher than in most developed countries, and this is taking its toll on the environment. Problems include severe surface...... water and groundwater pollution by nitrogen and pesticides, soil degradation, bioaccumulation of toxic compounds, and more. It is crucial for China to do improve the safeguarding of its water resources in order to sustain the livelihoods of its people and ensure safe supply of drinking water. Recently......-groundwater interaction was chosen, and field work was performed between October 2012 and March 2014. Results from the field study showed that fertilizer inputs were excessive, and could be reduced substantially. Contaminated river water was infiltrating – and carrying ammonium pollution – into the shallow groundwater...

  4. Integrated modelling for assessing the risk of groundwater contaminants to human health and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Rasmussen, Jes; Funder, Simon G.

    2010-01-01

    for evaluating the impact of a TCE groundwater plume, located in an area with protected drinking water interests, to human health and surface water ecosystems. This is accomplished by coupling the system dynamicsbased decision support system CARO-Plus to the aquatic ecosystem model AQUATOX via an analytical......The practical implementation of the European Water Framework Directive has resulted in an increased focus on the groundwater-surface water interaction zone. A gap exists with respect to preliminary assessment methodologies that are capable of evaluating and prioritising point sources...... volatilisation model for the stream. The model is tested on a Danish case study involving a 750 m long TCE groundwater plume discharging into a stream. The initial modelling results indicate that TCE contaminant plumes with μgL-1 concentrations entering surface water systems do not pose a significant risk...

  5. Spatial and statistical methods for correlating the interaction between groundwater contamination and tap water exposure in karst regions

    Science.gov (United States)

    Padilla, I. Y.; Rivera, V. L.; Macchiavelli, R. E.; Torres Torres, N. I.

    2016-12-01

    Groundwater systems in karst regions are highly vulnerable to contamination and have an enormous capacity to store and rapidly convey pollutants to potential exposure zones over long periods of time. Contaminants in karst aquifers used for drinking water purposes can, therefore, enter distributions lines and the tap water point of use. This study applies spatial and statistical analytical methods to assess potential correlations between contaminants in a karst groundwater system in northern Puerto Rico and exposure in the tap water. It focuses on chlorinated volatile organic compounds (CVOC) and phthalates because of their ubiquitous presence in the environment and the potential public health impacts. The work integrates historical data collected from regulatory agencies and current field measurements involving groundwater and tap water sampling and analysis. Contaminant distributions and cluster analysis is performed with Geographic Information System technology. Correlations between detection frequencies and contaminants concentration in source groundwater and tap water point of use are assessed using Pearson's Chi Square and T-Test analysis. Although results indicate that correlations are contaminant-specific, detection frequencies are generally higher for total CVOC in groundwater than tap water samples, but greater for phthalates in tap water than groundwater samples. Spatial analysis shows widespread distribution of CVOC and phthalates in both groundwater and tap water, suggesting that contamination comes from multiple sources. Spatial correlation analysis indicates that association between tap water and groundwater contamination depends on the source and type of contaminants, spatial location, and time. Full description of the correlations may, however, need to take into consideration variable anthropogenic interventions.

  6. Isotope and chemical techniques in assessing groundwater contamination from Metro Manila landfill

    International Nuclear Information System (INIS)

    Castaneda, Soledad S.; Almoneda, Rosalina V.; Ascano, Luz; Del Castillo, Lorena A.; Fernandez, Lourdes G.; Sucgang, Raymond J.; Iblan, Cynthia L.; Baui, Daniel G.

    2007-01-01

    The first objective of the investigations is establishing benchmark isotopic characteristics of water sources and baseline concentrations of main environmental parameters related to contamination from the landfill. Water samples were collected from the production wells and surface water in the municipalities in proximity of the landfill, in Rodriguez and in San Mateo. Stable isotope characterization of the deep groundwater and rivers shows isotopic values clustering along the LMWL with ae 18 O ranging from -7.5 promille to -6.5 promille and ae 2 H ranging from - 53.59 promille to -42.91. The shallow groundwater are more isotopically enriched trending towards the evaporation line, with mean ae 18 O and aeD values of -6.46 promille and -44.14 promille, respectively. The mean isotopic signatures of surface water, with mean ae 18 O of -7.19 promille and deep groundwater, with mean ae 18 O of -6.67 promille, in Rodriguez are significantly distinct. San Mateo groundwater appear to be more isotopically enriched, indicating recharge different from that of Rodriguez groundwater. Leachate from the landfill exhibits a distinct isotopic composition from the freshwaters, with ae 18 O and aeD values of -5.58 promille and -31.66 promille. The significant differences in the isotopic signatures of the different water sources in the study area would facilitate detection of contamination from leachate run-off to the surface water, and eventually, to the groundwater. Trace metals in the water samples collected, generally, were below the regulatory limits for drinking water and surface water. Results of elemental determination in the sediment samples obtained from rivers showed that aside from the major crustal elements, Zn, Cu, and Ni were also present in significant amount. (author)

  7. Rapid Analysis of Eukaryotic Bioluminescence to Assess Potential Groundwater Contamination Events

    Directory of Open Access Journals (Sweden)

    Zacariah L. Hildenbrand

    2015-01-01

    Full Text Available Here we present data using a bioluminescent dinoflagellate, Pyrocystis lunula, in a toxicological bioassay to rapidly assess potential instances of groundwater contamination associated with natural gas extraction. P. lunula bioluminescence can be quantified using spectrophotometry as a measurement of organismal viability, with normal bioluminescent output declining with increasing concentration(s of aqueous toxicants. Glutaraldehyde and hydrochloric acid (HCl, components used in hydraulic fracturing and shale acidization, triggered significant toxicological responses in as little as 4 h. Conversely, P. lunula was not affected by the presence of arsenic, selenium, barium, and strontium, naturally occurring heavy metal ions potentially associated with unconventional drilling activities. If exogenous compounds, such as glutaraldehyde and HCl, are thought to have been introduced into groundwater, quantification of P. lunula bioluminescence after exposure to water samples can serve as a cost-effective detection and risk assessment tool to rapidly assess the impact of putative contamination events attributed to unconventional drilling activity.

  8. Establishing indices for groundwater contamination risk assessment in the vicinity of hazardous waste landfills in China.

    Science.gov (United States)

    Li, Ying; Li, Jinhui; Chen, Shusheng; Diao, Weihua

    2012-06-01

    Groundwater contamination by leachate is the most damaging environmental impact over the entire life of a hazardous waste landfill (HWL). With the number of HWL facilities in China rapidly increasing, and considering the poor status of environmental risk management, it is imperative that effective environmental risk management methods be implemented. A risk assessment indices system for HWL groundwater contamination is here proposed, which can simplify the risk assessment procedure and make it more user-friendly. The assessment framework and indices were drawn from five aspects: source term, underground media, leachate properties, risk receptors and landfill management quality, and a risk assessment indices system consisting of 38 cardinal indicators was established. Comparison with multimedia models revealed that the proposed indices system was integrated and quantitative, that input data for it could be easily collected, and that it could be widely used for environmental risk assessment (ERA) in China. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  9. Resolving superimposed ground-water contaminant plumes characterized by chromium, nitrate, uranium, and technetium--99

    International Nuclear Information System (INIS)

    Hall, S.H.

    1990-02-01

    Leakage from a liquid waste storage and solar evaporation basin at the Hanford Site in southeastern Washington State has resulted in a ground-water contaminant plume characterized by nitrate, hexavalent chromium, uranium, and technetium-99. The plume is superimposed on a larger, pre-existing plume extending from upgradient sites and having the same suite of contaminants. However, the relative abundance of contaminant species is quite different for each plume source. Thus, characteristic concentration ratios, rather than concentrations of individual species, are used as geochemical tracers, with emphasis on graphical analysis. Accordingly, it has been possible to resolve the boundaries of the smaller plume and to estimate the contribution of each plume to the observed contamination downgradient from the storage basin. 11 refs., 7 figs

  10. Identification of Groundwater Nitrate Contamination from Explosives Used in Road Construction: Isotopic, Chemical, and Hydrologic Evidence.

    Science.gov (United States)

    Degnan, James R; Böhlke, J K; Pelham, Krystle; Langlais, David M; Walsh, Gregory J

    2016-01-19

    Explosives used in construction have been implicated as sources of NO3(-) contamination in groundwater, but direct forensic evidence is limited. Identification of blasting-related NO3(-) can be complicated by other NO3(-) sources, including agriculture and wastewater disposal, and by hydrogeologic factors affecting NO3(-) transport and stability. Here we describe a study that used hydrogeology, chemistry, stable isotopes, and mass balance calculations to evaluate groundwater NO3(-) sources and transport in areas surrounding a highway construction site with documented blasting in New Hampshire. Results indicate various groundwater responses to contamination: (1) rapid breakthrough and flushing of synthetic NO3(-) (low δ(15)N, high δ(18)O) from dissolution of unexploded NH4NO3 blasting agents in oxic groundwater; (2) delayed and reduced breakthrough of synthetic NO3(-) subjected to partial denitrification (high δ(15)N, high δ(18)O); (3) relatively persistent concentrations of blasting-related biogenic NO3(-) derived from nitrification of NH4(+) (low δ(15)N, low δ(18)O); and (4) stable but spatially variable biogenic NO3(-) concentrations, consistent with recharge from septic systems (high δ(15)N, low δ(18)O), variably affected by denitrification. Source characteristics of denitrified samples were reconstructed from dissolved-gas data (Ar, N2) and isotopic fractionation trends associated with denitrification (Δδ(15)N/Δδ(18)O ≈ 1.31). Methods and data from this study are expected to be applicable in studies of other aquifers affected by explosives used in construction.

  11. Spreading of Groundwater Contamined by Leached in the Surrounding Area of Piyungan Landfill Bantul District, Yogyakarta Province

    Directory of Open Access Journals (Sweden)

    J Sartohadi

    2017-07-01

    Full Text Available The objectives of this research are: (1 to study the characteristics of aquifer, distribution and chemical types of groundwater in the research area; (2 to measure the consentration of major elements (HC03-, Cl-, S042-, Ca2+, Mg2+, Na+, K+ and minor elements (S2-, NH4+ as indicators of leached contamination in the groundwater; and (3 to establish the spreading of contamined groundwater by leached. The grid sampling method was applied in this research. The grid dimension is 1 cm x 1 cm measured in the 1:25000 scale of Indonesian Topographic Map. The groundwater samples were taken randomly within the grid. Not the whole study area covered by the map was grided but only the surrounding area of Piyungan Landfill and the area lower than Piyungan landfill were grided. The groundwater samples were taken during the rainy season because during the rainy season there were more leached produced from Piyungan Landfill. The groundwater samples were examined their physical and chemical qualities using the legal standard quality in Yogyakarta Province. Spatial analysis using maps and graphics were applied to examine the spreading of contimined groundwater by leached. The spreading of unconfined groundwater in the study area was not equal distributed but it seems to be controlled by the landforms. There were an increasing elements content of Cl-, Ca2+, Mg2+ and HCO3-, as well as dissolved oxygen, NO3- and S2- in the groundwater contamined by leached. The zonation of the spreading of groundwater contamined by leached was categorized into three class, i.e., central (location of landfill, well number 1 0, transisional (well number: 11, 12, 13, 15, and primary (well number: 8, 14, 16, 17, 25, 26 zones. The zonation of groundwater matched with the analysis of groundwater quality by the distance from the Piyungan Landfill.

  12. Profiling micro-organic contaminants in groundwater using multi-level piezometers

    OpenAIRE

    White, Debbie; Lapworth, Dan; Stuart, Marianne; Williams, Peter

    2015-01-01

    The presence of micro-organic pollutants, including ‘emerging contaminants’ within groundwater is of increasing interest. Robust protocols are required to minimise the introduction of contamination during the sampling process. Below we discuss the sampling protocols used to reduce inputs of plasticisers during the sampling process, as well as the techniques used to characterise the distribution of micro-organic pollutants in the subsurface. In this study multi-level piezometers...

  13. Agriculture and groundwater nitrate contamination in the Seine basin. The STICS-MODCOU modelling chain

    International Nuclear Information System (INIS)

    Ledoux, E.; Gomez, E.; Monget, J.M.; Viavattene, C.; Viennot, P.; Ducharne, A.; Benoit, M.; Mignolet, C.; Schott, C.; Mary, B.

    2007-01-01

    A software package is presented here to predict the fate of nitrogen fertilizers and the transport of nitrate from the rooting zone of agricultural areas to surface water and groundwater in the Seine basin, taking into account the long residence times of water and nitrate in the unsaturated and aquifer systems. Information on pedological characteristics, land use and farming practices is used to determine the spatial units to be considered. These data are converted into input data for the crop model STICS which simulates the water and nitrogen balances in the soil-plant system with a daily time-step. A spatial application of STICS has been derived at the catchment scale which computes the water and nitrate fluxes at the bottom of the rooting zone. These fluxes are integrated into a surface and groundwater coupled model MODCOU which calculates the daily water balance in the hydrological system, the flow in the rivers and the piezometric variations in the aquifers, using standard climatic data (rainfall, PET). The transport of nitrate and the evolution of nitrate contamination in groundwater and to rivers is computed by the model NEWSAM. This modelling chain is a valuable tool to predict the evolution of crop productivity and nitrate contamination according to various scenarios modifying farming practices and/or climatic changes. Data for the period 1970-2000 are used to simulate the past evolution of nitrogen contamination. The method has been validated using available data bases of nitrate concentrations in the three main aquifers of the Paris basin (Oligocene, Eocene and chalk). The approach has then been used to predict the future evolution of nitrogen contamination up to 2015. A statistical approach allowed estimating the probability of transgression of different concentration thresholds in various areas in the basin. The model is also used to evaluate the cost of the damage resulting of the treatment of drinking water at the scale of a groundwater management

  14. Agriculture and groundwater nitrate contamination in the Seine basin. The STICS-MODCOU modelling chain

    Energy Technology Data Exchange (ETDEWEB)

    Ledoux, E. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France)]. E-mail: emmanuel.ledoux@ensmp.fr; Gomez, E. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France); Monget, J.M. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France); Viavattene, C. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France); Viennot, P. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France); Ducharne, A. [Laboratoire Sisyphe, CNRS/Universite Pierre et Marie Curie, Paris (France); Benoit, M. [INRA, Station de Recherche SAD, 662 avenue Louis Buffet, 88500 Mirecourt (France); Mignolet, C. [INRA, Station de Recherche SAD, 662 avenue Louis Buffet, 88500 Mirecourt (France); Schott, C. [INRA, Station de Recherche SAD, 662 avenue Louis Buffet, 88500 Mirecourt (France); Mary, B. [INRA, Unite d' Agronomie Laon-Reims-Mons, Laon (France)

    2007-04-01

    A software package is presented here to predict the fate of nitrogen fertilizers and the transport of nitrate from the rooting zone of agricultural areas to surface water and groundwater in the Seine basin, taking into account the long residence times of water and nitrate in the unsaturated and aquifer systems. Information on pedological characteristics, land use and farming practices is used to determine the spatial units to be considered. These data are converted into input data for the crop model STICS which simulates the water and nitrogen balances in the soil-plant system with a daily time-step. A spatial application of STICS has been derived at the catchment scale which computes the water and nitrate fluxes at the bottom of the rooting zone. These fluxes are integrated into a surface and groundwater coupled model MODCOU which calculates the daily water balance in the hydrological system, the flow in the rivers and the piezometric variations in the aquifers, using standard climatic data (rainfall, PET). The transport of nitrate and the evolution of nitrate contamination in groundwater and to rivers is computed by the model NEWSAM. This modelling chain is a valuable tool to predict the evolution of crop productivity and nitrate contamination according to various scenarios modifying farming practices and/or climatic changes. Data for the period 1970-2000 are used to simulate the past evolution of nitrogen contamination. The method has been validated using available data bases of nitrate concentrations in the three main aquifers of the Paris basin (Oligocene, Eocene and chalk). The approach has then been used to predict the future evolution of nitrogen contamination up to 2015. A statistical approach allowed estimating the probability of transgression of different concentration thresholds in various areas in the basin. The model is also used to evaluate the cost of the damage resulting of the treatment of drinking water at the scale of a groundwater management

  15. A Geochemical Reaction Model for Titration of Contaminated Soil and Groundwater at the Oak Ridge Reservation

    Science.gov (United States)

    Zhang, F.; Parker, J. C.; Gu, B.; Luo, W.; Brooks, S. C.; Spalding, B. P.; Jardine, P. M.; Watson, D. B.

    2007-12-01

    This study investigates geochemical reactions during titration of contaminated soil and groundwater at the Oak Ridge Reservation in eastern Tennessee. The soils and groundwater exhibits low pH and high concentrations of aluminum, calcium, magnesium, manganese, various trace metals such as nickel and cobalt, and radionuclides such as uranium and technetium. The mobility of many of the contaminant species diminishes with increasing pH. However, base additions to increase pH are strongly buffered by various precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior and associated geochemical effects is thus critical to evaluate remediation performance of pH manipulation strategies. This study was undertaken to develop a practical but generally applicable geochemical model to predict aqueous and solid-phase speciation during soil and groundwater titration. To model titration in the presence of aquifer solids, an approach proposed by Spalding and Spalding (2001) was utilized, which treats aquifer solids as a polyprotic acid. Previous studies have shown that Fe and Al-oxyhydroxides strongly sorb dissolved Ni, U and Tc species. In this study, since the total Fe concentration is much smaller than that of Al, only ion exchange reactions associated with Al hydroxides are considered. An equilibrium reaction model that includes aqueous complexation, precipitation, ion exchange, and soil buffering reactions was developed and implemented in the code HydroGeoChem 5.0 (HGC5). Comparison of model results with experimental titration curves for contaminated groundwater alone and for soil- water systems indicated close agreement. This study is expected to facilitate field-scale modeling of geochemical processes under conditions with highly variable pH to develop practical methods to control contaminant mobility at geochemically complex sites.

  16. Groundwater redox conditions and conductivity in a contaminant plume from geoelectrical investigations

    Directory of Open Access Journals (Sweden)

    V. Naudet

    2004-01-01

    Full Text Available Accurate mapping of the electrical conductivity and of the redox potential of the groundwater is important in delineating the shape of a contaminant plume. A map of redox potential in an aquifer is indicative of biodegradation of organic matter and of concentrations of redox-active components; a map of electrical conductivity provides information on the mineralisation of the groundwater. Both maps can be used to optimise the position of pumping wells for remediation. The self-potential method (SP and electrical resistivity tomography (ERT have been applied to the contaminant plume associated with the Entressen landfill in south-east France. The self-potential depends on groundwater flow (electrokinetic contribution and redox conditions ('electro-redox' contribution. Using the variation of the piezometric head in the aquifer, the electrokinetic contribution is removed from the SP signals. A good linear correlation (R2=0.85 is obtained between the residual SP data and the redox potential values measured in monitoring wells. This relationship is used to draw a redox potential map of the overall contaminated site. The electrical conductivity of the subsoil is obtained from 3D-ERT analysis. A good linear correlation (R2=0.91 is observed between the electrical conductivity of the aquifer determined from the 3D-ERT image and the conductivity of the groundwater measured in boreholes. This indicates that the formation factor is nearly homogeneous in the shallow aquifer at the scale of the ERT. From this correlation, a map of the pore water conductivity of the aquifer is obtained. Keywords: self-potential, redox potential, electrical resistivity tomography, fluid conductivity, contaminant plume

  17. Preconcentration for Improved Long-term Monitoring of Contaminants in Groundwater

    Science.gov (United States)

    2014-04-10

    facilities where waste from weapons manufacture, storage, and reclamation processes has leached into the soil and groundwater. Key contaminants...and current testing and training facilities where waste from weapons manufacture, storage, and reclamation processes has leached into the soil and...scale, bread -board level, prototype was assembled using a peristaltic pump with a 900:1 motor and 0.143” rollers (P625/900.143, Instech Laboratories

  18. The influence of interfacial properties on the two-phase liquid flow of organic contaminants in groundwater

    International Nuclear Information System (INIS)

    Demond, A.H.; Desai, F.N.; Hayes, K.F.

    1992-01-01

    DOE's waste sites are contaminated with a variety of organic liquids. Because of their low solubility in water, organic liquids such as these will persist as separate liquid phases and be transported as such in the subsurface. Thus, an improved understanding of the factors influencing the movement of a separate organic liquid phase in the subsurface is important to DOE's efforts to control groundwater contamination. Wettability is sometimes cited as the most important factor influencing two-phase flow in porous media. The wetting phase migrates preferentially through the smaller pores, whereas the nonwetting phase is concentrated in the larger pores. Typically, aquifers are thought of as strongly water-wet, implying that the organic liquid preferentially occupies the larger pores. But in fact, that state depends on the properties of the three interfaces of the system: between the organic liquid and water, water and the solid, and the organic liquid and the solid. Characteristics of the system which affect the interfacial properties also impact the wettability, such as the nature of the aquifer solids' surfaces, the composition of the goundwater and the properties of the organic contaminant. The alteration of wettability at DOE waste sites may be dominated by the presence of co-contaminants such as organic acids and bases which behave as surface-active agents or surfactants. Because of their physicochemical nature, surfactants will sorb preferentially at the interfaces of the system, thereby impacting the wettability and the distribution of the liquids in the porous medium. The over-all objective of this research was to determine how changes in interfacial properties affect two-phase flow. Specifically, the objective was to examine the effect of surfactant sorption on capillary pressure relationships by correlating measurements of sorption, zeta potential, interfacial tension and contact angle, with changes in the capillary pressure-saturation relationships

  19. PILOT STUDIES OF IN-SITU BIO-TRANSFORMATION OF MERCURY-CONTAMINATED GROUNDWATER IN KAZAKHSTAN UTILIZING NATIVE BACTERIA

    Science.gov (United States)

    Several regions in the Republic of Kazakhstan and throughout the former USSR are contaminated with mercury resulting from industrial releases. Our studies directed towards determining the feasibility of developing a biological filter, which when placed into the path the groundwat...

  20. Baseline risk assessment for groundwater contamination at the uranium mill tailings site near Monument Valley, Arizona. Draft

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    This baseline risk assessment evaluates potential impact to public health or the environment resulting from groundwater contamination at the former uranium mill processing site near Monument Valley, Arizona. The tailings and other contaminated material at this site are being relocated and stabilized in a disposal cell at Mexican Hat, Utah, through the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The tailings removal is planned for completion by spring 1994. After the tailings are removed, groundwater contamination at the site will continue to be evaluated. This risk assessment is the first document specific to this site for the Groundwater Project. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site.

  1. Relating groundwater and sediment chemistry to microbial characterization at a BTEX-contaminated site

    International Nuclear Information System (INIS)

    Pfiffner, S.M.; Palumbo, A.V.; McCarthy, J.F.; Gibson, T.

    1996-01-01

    The National Center for Manufacturing Science is investigating bioremediation of petroleum hydrocarbon at a site in Belleville, Michigan. As part of this study we examined the microbial communities to help elucidate biodegradative processes currently active at the site. We observed high densities of aerobic hydrocarbon degraders and denitrifiers in the less-contaminated sediments. Low densities of iron and sulfate reducers were measured in the same sediments. In contrast, the highly-contaminated sediments showed low densities of aerobic hydrocarbon degraders and denitrifiers and high densities of iron and sulfate reducers. Methanogens were also found in these highly-contaminated sediments. These contaminated sediments also showed a higher biomass, by phospholipid fatty acids, and greater ratios of phospholipid fatty acids which indicate stress within the microbial community. Aquifer chemistry analyses indicated that the more-contaminated area was more reduced and had lower sulfate than the less-contaminated area. These conditions suggest that the subsurface environment at the highly-contaminated area had progressed into sulfate reduction and methanogensis. The less-contaminated area, although less reduced, also appeared to be progressing into primarily iron- and sulfate-reducing microbial communities. The proposed treatment to stimulate bioremediation includes addition of oxygen and nitrate. Groundwater chemistry and microbial analyses revealed significant differences resulted from the injection of dissolved oxygen and nitrate in the subsurface. These differences included increases in pH and Eh and large decreases in BTEX, dissolved iron, and sulfate concentrations at the injection well

  2. Point bars as stratigraphic traps for arsenic contamination in groundwater : Case study of the Ganges River, Bihar, India (abstract)

    NARCIS (Netherlands)

    Donselaar, M.E.; Bhatt, A.G.; Bruining, J.; Bose, N.; Ghosh, A.K.

    2013-01-01

    Arsenic-contaminated groundwater causes a wide-spread, serious health risk affecting millions of people worldwide. Focus of the research is the floodplain of the Ganges River in the State of Bihar (India) where groundwater is the principal source of drinking water and irrigation, and where the

  3. Assessment of ground-water contamination from a leaking underground storage tank at a defense supply center near Richmond, Virginia

    International Nuclear Information System (INIS)

    Powell, J.D.; Wright, W.G.

    1990-01-01

    During 1988-89, 24 wells were installed in the vicinity of the post-exchange gasoline station on the Defense General Supply Center, near Richmond, Virginia, to collect and analyze groundwater samples for the presence of gasoline contamination from a leaking underground storage tank. Concentrations of total petroleum hydrocarbons and benzene were as high as 8.2 mg/L and 9,000 microg/L, respectively, in water from wells in the immediate vicinity of the former leaking tank, and benzene concentrations were as high as 2,300 microg/L in a well 600 ft down gradient from the gasoline station. Groundwater flow rate are estimated to be about 60 to 80 ft/yr; on the basis of these flow rates, the contaminants may have been introduced into the groundwater as long as 7-10 yrs ago. Groundwater might infiltrate a subsurface storm sewer, where the sewer is below the water table, and discharge into a nearby stream. Preliminary risk assessment for the site identified no potential human receptors to the groundwater contamination because there were no groundwater users identified in the area. Remediation might be appropriate if exposure of future potential users is concern. Alternatives discussed for remediation of groundwater contamination in the upper aquifer at the PX Service Station include no-action, soil vapor extraction, and groundwater pumping and treatment alternatives

  4. Removal of arsenic from contaminated groundwater by solar-driven membrane distillation

    International Nuclear Information System (INIS)

    Manna, Ajay K.; Sen, Mou; Martin, Andrew R.; Pal, Parimal

    2010-01-01

    Experimental investigations were carried out on removal of arsenic from contaminated groundwater by employing a new flat-sheet cross flow membrane module fitted with a hydrophobic polyvinylidenefluoride (PVDF) microfiltration membrane. The new design of the solar-driven membrane module in direct contact membrane distillation (DCMD) configuration successfully produced almost 100 per cent arsenic-free water from contaminated groundwater in a largely fouling-free operation while permitting high fluxes under reduced temperature polarization. For a feed flow rate of 0.120 m 3 /h, the 0.13 μm PVDF membrane yielded a high flux of 74 kg/(m 2 h) at a feed water temperature of 40 deg. C and, 95 kg/m 2 h at a feed water temperature of 60 deg. C. The encouraging results show that the design could be effectively exploited in the vast arsenic-affected rural areas of South-East Asian countries blessed with abundant sunlight particularly during the critical dry season. - Solar-driven membrane distillation has the potential of removing arsenic from contaminated groundwater.

  5. Atrazine Contamination in Groundwater at Ejura in the Ashanti Region of Ghana

    International Nuclear Information System (INIS)

    Quaye, F.A.

    2012-01-01

    The present study the levels Atrazine, deethylatrazine(DEA) and deisopropylatrazine(DIA) in groundwater at Ejura within the Ejura-Sekyedumase District in the Ashanti region of Ghana which is a major maize growing area in the country. A total of twenty five (25) groundwater samples were collected from six(6) sampling sites within the sampling area and were analyzed using a Varian ProstaHPLC system (410) + autosampler, photodiote array (PDA) detector, UV and fluorescence detectors. The mean concentration of atrazine in the groundwater at Ejura is 0.255 μ/L. The maximum concentration of atrazine was 1.530μ/L and a minimum concentration of 0.20μ/L. The maximum and minimum concentrations for deethylatrazine (DEA) and deisopropylatrazine (DIA) are 0.423μ/L and 0.101μ/L and 0.204μ/L and 0.102μL respectively. The Deethylatrazine to Atrazine Ratio (DAR) was calculated; the values were much less than one suggesting a discrete source of contamination. This gives an indication of the pathway of atrazine contamination as being preferential flow. The levels of Atrazine deethylatrazine (DEA) and deisopropylatrazine (DIA) from the samples analyzed were all below WHO's maximum contamination levels (MCL), 2μ/L. (author)

  6. SITE demonstration of the Dynaphore/Forager Sponge technology to remove dissolved metals from contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, C.R. [Environmental Protection Agency, Edison, NJ (United States); Vaccaro, G. [Science Applications International Corp., Hackensack, NJ (United States)

    1995-10-01

    A Superfund Innovative Technology Evaluation (SITE) demonstration was conducted of the Dynaphore/Forager Sponge technology during the week of April 3, 1994 at the N.L. Industries Superfund Site in Pedricktown, New Jersey. The Forager Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that selectively absorbs dissolved heavy metals in both cationic and anionic states. This technology is a volume reduction technology in which heavy metal contaminants from an aqueous medium are concentrated into a smaller volume for facilitated disposal. The developer states that the technology can be used to remove heavy metals from a wide variety of aqueous media, such as groundwater, surface waters and process waters. The sponge matrix can be directly disposed, or regenerated with chemical solutions. For this demonstration the sponge was set up as a mobile pump-and-treat system which treated groundwater contaminated with heavy metals. The demonstration focused on the system`s ability to remove lead, cadmium, chromium and copper from the contaminated groundwater over a continuous 72-hour test. The removal of heavy metals proceeded in the presence of significantly higher concentrations of innocuous cations such as calcium, magnesium, sodium, potassium and aluminum.

  7. Assessing Contamination Potential of Nitrate-N in Groundwater of Lanyang Plain

    Science.gov (United States)

    Liang, Ching-Ping; Tu, Yu-Lin; Lin, Chien-Wen; Jang, Cheng-Shin

    2013-04-01

    Nitrate-N pollution is often relevant to agricultural activities such as the fertilization of crops. Significant increases in the nitrate-N pollution of groundwater are found in natural recharging zones of Taiwan. The increasing nitrate-N contamination seriously threatens public drinking water supply and human health. Constructing a correct map of aquifer contamination potential is an effective and feasible way to protect groundwater for quality assessment and management. Therefore, in this study, we use DRASTIC model with the help of geographic information system (GIS) to assess and predict the contamination potential of nitrate-N in the aquifer of Lanyang Plain, Taiwan. Seven factors of hydrogeology and hydrology, which includes seven parameters - Depth to groundwater, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and hydraulic Conductivity, are considered to carry out this assessment. The validity of the presented model is established by comparing the results with the measured nitrate concentration in wells within the study area. Adjusting factor weightings via the discriminant analysis is performed to improve the assessment and prediction. The analyzed results can provide residents with suggestive strategies against nitrate-N pollution in agricultural regions and government administrators with explicit information of Nitrate-N pollution extents when plans of water resources are considered.

  8. An approach to delineate the contaminated groundwater in landfill based on Electrical Resistivity Imaging Technique

    International Nuclear Information System (INIS)

    Nor Dalila Desa; Lakam Mejus; Mohd Tadza Abdul Rahman; Kamarudin Samuding; Roslanzairi Mostapa; Mod Omar Hassan

    2010-01-01

    Full text: The occurrence of contaminated groundwater can often be recognized by a decrease in formation of resistivity values, since the latter is primarily dependent on the resistivity of the pore water. Landfills can be considered as one of major source of contamination that contributes to air, land and water pollution. Landfills are supposed to have a protective bottom layer (barrier layer) to prevent contaminants from getting into the groundwater that exist almost everywhere underground. However, if there is no layer or if it is cracked, water percolating through landfills produces leachate can make their way down into the groundwater system. In geophysical studies, the various properties of materials on earth are known as the anomaly of the Earth's sub surface. It is important to understand which physical properties are associated with, and effective for, a particular target and geophysical method. This paper reviews the needs of geophysical field for mapping subsurface geology and features occurance. Electrical Resistivity Imaging (ERI) technique has been chosen for it has become one of the promising methods in order to obtain preliminary information of subsurface variance materials based on their physical properties. (author)

  9. Predicting redox-sensitive contaminant concentrations in groundwater using random forest classification

    Science.gov (United States)

    Tesoriero, Anthony J.; Gronberg, Jo Ann; Juckem, Paul F.; Miller, Matthew P.; Austin, Brian P.

    2017-08-01

    Machine learning techniques were applied to a large (n > 10,000) compliance monitoring database to predict the occurrence of several redox-active constituents in groundwater across a large watershed. Specifically, random forest classification was used to determine the probabilities of detecting elevated concentrations of nitrate, iron, and arsenic in the Fox, Wolf, Peshtigo, and surrounding watersheds in northeastern Wisconsin. Random forest classification is well suited to describe the nonlinear relationships observed among several explanatory variables and the predicted probabilities of elevated concentrations of nitrate, iron, and arsenic. Maps of the probability of elevated nitrate, iron, and arsenic can be used to assess groundwater vulnerability and the vulnerability of streams to contaminants derived from groundwater. Processes responsible for elevated concentrations are elucidated using partial dependence plots. For example, an increase in the probability of elevated iron and arsenic occurred when well depths coincided with the glacial/bedrock interface, suggesting a bedrock source for these constituents. Furthermore, groundwater in contact with Ordovician bedrock has a higher likelihood of elevated iron concentrations, which supports the hypothesis that groundwater liberates iron from a sulfide-bearing secondary cement horizon of Ordovician age. Application of machine learning techniques to existing compliance monitoring data offers an opportunity to broadly assess aquifer and stream vulnerability at regional and national scales and to better understand geochemical processes responsible for observed conditions.

  10. Evaluation of the fate of arsenic-contaminated groundwater at different aquifers of Thar coalfield Pakistan.

    Science.gov (United States)

    Ali, Jamshed; Kazi, Tasneem G; Baig, Jameel A; Afridi, Hassan I; Arain, Mariam S; Ullah, Naeem; Brahman, Kapil D; Arain, Sadaf S; Panhwar, Abdul H

    2015-12-01

    In present study, the ground water at different aquifers was evaluated for physicochemical parameters, iron, total arsenic, total inorganic arsenic and arsenic species (arsenite and arsenate). The samples of groundwater were collected at different depths, first aquifer (AQ1) 50-60 m, second aquifer (AQ2) 100-120 m, and third aquifer (AQ3) 200-250 m of Thar coalfield, Pakistan. Total inorganic arsenic was determined by solid phase extraction using titanium dioxide as an adsorbent. The arsenite was determined by cloud point extraction using ammonium pyrrolidinedithiocarbamate as a chelating reagent, and resulted complex was extracted by Triton X-114. The resulted data of groundwater were reported in terms of basic statistical parameters, principal component, and cluster analysis. The resulted data indicated that physicochemical parameters of groundwater of different aquifers were exceeded the World Health Organization provisional guideline for drinking water except pH and SO4(2-). The positive correlation was observed between arsenic species and physicochemical parameters of groundwater except F(-) and K(+), which might be caused by geochemical minerals. Results of cluster analysis indicated that groundwater samples of AQ1 was highly contaminated with arsenic species as compared to AQ2 and AQ3 (p > 0.05).

  11. Permeable Asphalt: A New Tool to Reduce Road Salt Contamination of Groundwater in Urban Areas.

    Science.gov (United States)

    Dietz, Michael E; Angel, Derek R; Robbins, Gary A; McNaboe, Lukas A

    2017-03-01

    Chloride contamination of groundwater in urban areas due to deicing is a well-documented phenomenon in northern climates. The objective of this study was to evaluate the effects of permeable pavement on degraded urban groundwater. Although low impact development practices have been shown to improve stormwater quality, no infiltration practice has been found to prevent road salt chlorides from entering groundwater. The few studies that have investigated chlorides in permeable asphalt have involved sampling directly beneath the asphalt; no research has looked more broadly at surrounding groundwater conditions. Monitoring wells were installed upgradient and downgradient of an 860 m 2 permeable asphalt parking lot at the University of Connecticut (Storrs, Connecticut). Water level and specific conductance were measured continuously, and biweekly samples were analyzed for chloride. Samples were also analyzed for sodium (Na), calcium (Ca), and magnesium (Mg). Analysis of variance analysis indicated a significantly (p monitoring revealed lower Cl concentrations downgradient than upgradient for the majority of the year. These results suggest that the use of permeable asphalt in impacted urban environments with high ambient chloride concentrations can be beneficial to shallow groundwater quality, although these results may not be generalizable to areas with low ambient chloride concentrations. © 2016, National Ground Water Association.

  12. In-situ bioremediation of TCE-contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Travis, B.J. [Los Alamos National Lab., NM (United States); Rosenberg, N.D. [Lawrence Livermore National Lab., CA (United States)

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). A barrier to wider use of in situ bioremediation technology is that results are often variable and difficult to predict. In situ bioremediation has shown some very notable and well publicized successes, but implementation of the technology is complex. An incomplete understanding of the effects of variable site characteristics and the lack of adequate tools to predict and measure success have made the design, control and validation of bioremediation more empirical than desired. The long-term objective of this project is to improve computational tools used to assess and optimize the expected performance of bioremediation at a site. An important component of the approach is the explicit inclusion of uncertainties and their effect on the end result. The authors have extended their biokinetics model to include microbial competition and predation processes. Predator species can feed on the microbial species that degrade contaminants, and the simulation studies show that species interactions must be considered when designing in situ bioremediation systems. In particular, the results for TCE indicate that protozoan grazing could reduce the amount of biodegradation by about 20%. These studies also indicate that the behavior of barrier systems can become complex due to predator grazing.

  13. Potential for saturated ground-water system contamination at the Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Stone, R.; Ruggieri, M.R.; Rogers, L.L.; Emerson, D.O.; Buddemeier, R.W.

    1982-01-01

    A program of hydrogeologic investigation has been carried out to determine the likelihood of contaminant movement to the saturated zone from near the ground surface at Lawrence Livermore National Laboratory (LLNL). A companion survey of potential contaminant sources was also conducted at the LLNL. Water samples from selected LLNL wells were analyzed to test the water quality in the uppermost part of the saturated zone, which is from 14 to 48 m (45 to 158 ft) beneath the surface. Only nitrate and tritium were found in concentrations above natural background. In one well, the nitrate was slightly more concentrated than the drinking water limit. The nitrate source has not been found. The tritium in all ground-water samples from wells was found far less concentrated than the drinking water limit. The extent of infiltration of surface water was traced with environmental tritium. The thickness and stratigraphy of the unsaturated zone beneath the LLNL, and nearby area, was determined with specially constructed wells and boreholes. Well hydrograph analysis indicated where infiltration of surface water reached the saturated ground-water system. The investigation indicates that water infiltrating from the surface, through alluvial deposits, reaches the saturated zone along the course of Arroyo Seco, Arroyo Las Positas, and from the depression near the center of the site where seasonal water accumulates. Several potential contaminant sources were identified, and it is likely that contaminants could move from near the ground surface to the saturated zone beneath LLNL. Additional ground-water sampling and analysis will be performed and ongoing investigations will provide estimates of the speed with which potential contaminants can flow laterally in the saturated zone beneath LLNL. 34 references, 61 figures, 16 tables

  14. The effect of remedial measures upon groundwater quality in connection with soil contamination by chlorinated hydrocarbons and the related costs - by example of the City of Hanover

    International Nuclear Information System (INIS)

    Mull, R.; Mull, J.; Pielke, M.

    1992-01-01

    The effectiveness of remedial actions on the groundwater quality was investigated in the aquifer of the City of Hannover. The improvement of groundwater quality was related to the costs for the remedial actions. The attention was focussed on groundwater pollution by chlorinated hydrocarbons as the most important contaminants of groundwater in urban areas. (orig.)

  15. In situ disinfection of sewage contaminated shallow groundwater: a feasibility study.

    Science.gov (United States)

    Bailey, Morgan M; Cooper, William J; Grant, Stanley B

    2011-11-01

    Sewage-contaminated shallow groundwater is a potential cause of beach closures and water quality impairment in marine coastal communities. In this study we set out to evaluate the feasibility of several strategies for disinfecting sewage-contaminated shallow groundwater before it reaches the coastline. The disinfection rates of Escherichia coli (EC) and enterococci bacteria (ENT) were measured in mixtures of raw sewage and brackish shallow groundwater collected from a coastal community in southern California. Different disinfection strategies were explored, ranging from benign (aeration alone, and aeration with addition of brine) to aggressive (chemical disinfectants peracetic acid (PAA) or peroxymonosulfate (Oxone)). Aeration alone and aeration with brine did not significantly reduce the concentration of EC and ENT after 6 h of exposure, while 4-5 mg L(-1) of PAA or Oxone achieved >3 log reduction after 15 min of exposure. Oxone disinfection was more rapid at higher salinities, most likely due to the formation of secondary oxidants (e.g., bromine and chlorine) that make this disinfectant inappropriate for marine applications. Using a Lagrangian modeling framework, we identify several factors that could influence the performance of in-situ disinfection with PAA, including the potential for bacterial regrowth, and the non-linear dependence of disinfection rate upon the residence time of water in the shallow groundwater. The data and analysis presented in this paper provide a framework for evaluating the feasibility of in-situ disinfection of shallow groundwater, and elucidate several topics that warrant further investigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Suitability of artificial sweeteners as indicators of raw wastewater contamination in surface water and groundwater.

    Science.gov (United States)

    Tran, Ngoc Han; Hu, Jiangyong; Li, Jinhua; Ong, Say Leong

    2014-01-01

    There is no quantitative data on the occurrence of artificial sweeteners in the aquatic environment in Southeast Asian countries, particularly no information on their suitability as indicators of raw wastewater contamination on surface water and groundwater. This study provided the first quantitative information on the occurrence of artificial sweeteners in raw wastewater, surface water and groundwater in the urban catchment area in Singapore. Acesulfame, cyclamate, saccharin, and sucralose were ubiquitous in raw wastewater samples at concentrations in the range of ng/L-μg/L, while other sweeteners were not found or found only in a few of the raw wastewater samples. Residential and commercial effluents were demonstrated to be the two main sources of artificial sweeteners entering the municipal sewer systems. Relatively higher concentrations of the detected sweeteners were frequently found in surface waters at the sampling sites located in the residential/commercial areas. No significant difference in the concentrations of the detected sweeteners in surface water or groundwater was noted between wet and dry weather conditions (unpaired T-test, p> 0.05). Relatively higher concentrations and detection frequencies of acesulfame, cyclamate and saccharin in surface water samples were observed at the potentially impacted sampling sites, while these sweeteners were absent in most of the background surface water samples. Similarly, acesulfame, cyclamate, and saccharin were found in most groundwater samples at the monitoring well (GW6), which is located close to known leaking sewer segment; whereas these were absent in the background monitoring well, which is located in the catchment with no known wastewater sources. Taken together, the results suggest that acesulfame, cyclamate, and saccharin can be used as potential indicators of raw wastewater contamination in surface water and groundwater. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Large scale treatment of total petroleum-hydrocarbon contaminated groundwater using bioaugmentation.

    Science.gov (United States)

    Poi, Gregory; Shahsavari, Esmaeil; Aburto-Medina, Arturo; Mok, Puah Chum; Ball, Andrew S

    2018-05-15

    Bioaugmentation or the addition of microbes to contaminated sites has been widely used to treat contaminated soil or water; however this approach is often limited to laboratory based studies. In the present study, large scale bioaugmentation has been applied to total petroleum hydrocarbons (TPH)-contaminated groundwater at a petroleum facility. Initial TPH concentrations of 1564 mg L -1 in the field were reduced to 89 mg L -1 over 32 days. This reduction was accompanied by improved ecotoxicity, as shown by Brassica rapa germination numbers that increased from 52 at day 0 to 82% by the end of the treatment. Metagenomic analysis indicated that there was a shift in the microbial community when compared to the beginning of the treatment. The microbial community was dominated by Proteobacteria and Bacteroidetes from day 0 to day 32, although differences at the genus level were observed. The predominant genera at the beginning of the treatment (day 0 just after inoculation) were Cloacibacterium, Sediminibacterium and Brevundimonas while at the end of the treatment members of Flavobacterium dominated, reaching almost half the population (41%), followed by Pseudomonas (6%) and Limnobacter (5.8%). To the author's knowledge, this is among the first studies to report the successful large scale biodegradation of TPH-contaminated groundwater (18,000 L per treatment session) at an offshore petrochemical facility. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Laboratory evaluation of the potential for in situ treatment of chromate-contaminated groundwater by chemical precipitation

    International Nuclear Information System (INIS)

    Thornton, E.C.; Beck, M.A.; Jurgensmeier, C.A.

    1995-03-01

    The objective of this paper is to present the results of a series of small-scale batch tests performed to assess the effectiveness of chemical precipitation in the remediation of chromate-contaminated groundwater. These tests involved treatment of chromate solutions with ferrous and sulfide ions. In addition, tests were conducted that involved treatment of mixtures of chromate-contaminated groundwater and uncontaminated soil with the ferrous ion. A combination of ferrous sulfate and sodium sulfide was also tested in the groundwater treatment tests, since this approach has been shown to be an efficient method for treating electroplating wastewaters

  19. Speciation of As in calcite by micro-XAFS: Implications for remediation of As contamination in groundwater

    International Nuclear Information System (INIS)

    Yokoyama, Y; Takahashi, Y; Iwatsuki, T; Terada, Y

    2013-01-01

    To evaluate the role of calcite as a host phase of arsenic (As) in As-contaminated groundwater, distribution behavior of Asbetween natural calcite and groundwater in deep underground was investigated based on As oxidation state. Speciation analyses of As in natural calcite by μ-XRF-XAFS analyses showed (i) preferentialarsenate uptake by calcite, and (ii) promptness of arsenate uptake by minor iron (Fe) carbonate minerals coprecipitated with calcite. These findings suggest that the effect of calcite on As remediation of the As-contamination systems stronglydepends on arsenite to arsenate ratio (i.e., redox condition) in groundwater, and maybe governed bythe amount of Fe coprecipitated with calcite.

  20. Modeling Contamination Migration on the Chandra X-ray Observatory - II

    Science.gov (United States)

    O'Dell, Stephen L.; Swartz, Douglas A.; Tice, Neil W.; Plucinsky, Paul P.; Grant, Catherine E.; Marshall, Herman L.; Vikhlinin, Alexey A.; Tennant, Allyn F.

    2013-01-01

    During its first 14 years of operation, the cold (about -60C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition have changed. This evolution has motivated further analysis of contamination migration within and near the ACIS cavity. To this end, the current study employs a higher-fidelity geometric model of the ACIS cavity, detailed thermal modeling based upon temperature data, and a refined model of the molecular transport.

  1. Pathways of sulfate and hydrogen sulfide transformations in a BTEX- contaminated groundwater system

    DEFF Research Database (Denmark)

    Einsiedl, Florian; Anneser, B.; Griebler, C.

    2010-01-01

    in complex environmental systems. As a result, compound specific stable isotope signatures in various sulfur species were determined in a tar-oil contaminated site and were linked to the microbial community distribution in the aquifer. The goal of the study was to reach an integrated understanding of sulfur...... intermediate during abiotic oxidation of hydrogen sulphide, with the latter formed during bacterial sulfate reduction. The formed elemental sulfur may be used by the specific microbial community found in this aquifer for the oxidation of organic contaminants such as toluene. In contrast, reoxidation...... of hydrogen sulfide to sulfate by molecular oxygen may affect sulfur cycling within the transition between the unsaturated and the saturated zones and therefore attenuate concentrations of contaminants in groundwater as well....

  2. Soil and groundwater contamination with heavy metals at two scrap iron and metal recycling facilities

    DEFF Research Database (Denmark)

    Jensen, Dorthe Lærke; Holm, P. E.; Christensen, Thomas Højlund

    2000-01-01

    Field studies were performed at two actual scrap iron and metal recycling facilities in order to evaluate the extent of heavy metal migration into subsoil and groundwater caused by more than 25 years of handling scrap directly on the ground without any measures to prevent leaching. Surface soil...... samples, called `scrap dirt', representing the different activities on the two recycling facilities, all showed very high concentrations of lead (Pb), copper (Cu) and zinc (Zn), high concentrations of cadmium (Cd) , chromium (Cr) and nickel (Ni) and somewhat elevated concentrations of many other metals....... In particular high concentrations were found for Pb at the car-battery salvage locations (13 to 26 g Pb kg±1) and Cu at the cable burning location (22 g Cu kg±1) at one site. The migration of metals below the surface in general (except at the car-battery salvage locations) was very limited even after...

  3. Numerical simulation of cesium and strontium migration through sodium bentonite altered by cation exchange with groundwater components

    International Nuclear Information System (INIS)

    Jacobsen, J.S.; Carnahan, C.L.

    1988-10-01

    Numerical simulations have been used to investigate how spatial and temporal changes in the ion exchange properties of bentonite affect the migration of cationic fission products from high-level waste. Simulations in which fission products compete for exchange sites with ions present in groundwater diffusing into the bentonite are compared to simulations in which the exchange properties of bentonite are constant. 12 refs., 3 figs., 2 tabs

  4. Impacts of physical and chemical aquifer heterogeneity on basin-scale solute transport: Vulnerability of deep groundwater to arsenic contamination in Bangladesh

    Science.gov (United States)

    Michael, Holly A.; Khan, Mahfuzur R.

    2016-12-01

    Aquifer heterogeneity presents a primary challenge in predicting the movement of solutes in groundwater systems. The problem is particularly difficult on very large scales, across which permeability, chemical properties, and pumping rates may vary by many orders of magnitude and data are often sparse. An example is the fluvio-deltaic aquifer system of Bangladesh, where naturally-occurring arsenic (As) exists over tens of thousands of square kilometers in shallow groundwater. Millions of people in As-affected regions rely on deep (≥150 m) groundwater as a safe source of drinking water. The sustainability of this resource has been evaluated with models using effective properties appropriate for a basin-scale contamination problem, but the extent to which preferential flow affects the timescale of downward migration of As-contaminated shallow groundwater is unknown. Here we embed detailed, heterogeneous representations of hydraulic conductivity (K), pumping rates, and sorptive properties (Kd) within a basin-scale numerical groundwater flow and solute transport model to evaluate their effects on vulnerability and deviations from simulations with homogeneous representations in two areas with different flow systems. Advective particle tracking shows that heterogeneity in K does not affect average travel times from shallow zones to 150 m depth, but the travel times of the fastest 10% of particles decreases by a factor of ∼2. Pumping distributions do not strongly affect travel times if irrigation remains shallow, but increases in the deep pumping rate substantially reduce travel times. Simulation of advective-dispersive transport with sorption shows that deep groundwater is protected from contamination over a sustainable timeframe (>1000 y) if the spatial distribution of Kd is uniform. However, if only low-K sediments sorb As, 30% of the aquifer is not protected. Results indicate that sustainable management strategies in the Bengal Basin should consider impacts of both

  5. Topsoil N-budget model in orchard farming to evaluate groundwater nitrate contamination

    Science.gov (United States)

    Wijayanti, Yureana; Budihardjo, Kadarwati; Sakamoto, Yasushi; Setyandito, Oki

    2017-12-01

    A small scale field research was conducted in an orchard farming area in Kofu, Japan, where nitrate contamination was found in groundwater. The purpose of assessing the leaching of nitrate in this study is to understand the transformation and transport process of N-source in topsoil that leads to nitrate contamination of groundwater. In order to calculate N-budget in the soil, the model was utilized to predict the nitrogen leaching. In this res earch, the N-budget model was modified to evaluate influence of precipitation and application pattern of fertilizer and manure compost. The result shows that at the time before the addition of manure compost and fertilizer, about 75% of fertilizer leach from topsoil. Every month, the average remaining nitrate in soil from fertilizer and manure compost are 22% and 50%, respectively. The accumulation of this monthly manure compost nitrate, which stored in soil, should be carefully monitored. It could become the potential source of nitrate leaching to groundwater in the future.

  6. Hydraulic performance of permeable barriers for in situ treatment of contaminated groundwater

    International Nuclear Information System (INIS)

    Smyth, D.J.A.; Shikaze, S.G.; Cherry, J.A.

    1997-01-01

    The passive interception and in situ treatment of dissolved contaminants in groundwater by permeable reactive barriers has recently gained favor at an increasing number of sites as an alternative to conventional approaches to groundwater remediation such as the pump-and-treat method. Permeable reactive barriers have two essential functions. The first is that the barriers must be installed in a position such that all of the plume passes through the reactive system. The second function is to achieve acceptable treatment of the contamination by physical, chemical or biological means within or downgradient of the barrier. In this paper, issues associated with the hydraulic performance of permeable reaction barriers are evaluated using a three-dimensional groundwater flow model. The efficiency of plume capture by permeable wall and funnel-and-gate systems is examined for some generic and for site-specific hydrogeologic systems. The results have important implications to decisions pertaining to the selection, design and installation of permeable reactive barrier systems

  7. Development and applications of two finite element groundwater flow and contaminant transport models: FEWA and FEMA

    International Nuclear Information System (INIS)

    Yeh, G.T.; Wong, K.V.; Craig, P.M.; Davis, E.C.

    1985-01-01

    This paper presents the construction, verification, and application of two groundwater flow and contaminant transport models: A Finite Element Model of Water Flow through Aquifers (FEWA) and A Finite Element Model of Material Transport through Aquifers (FEMA). The construction is based on the finite element approximation of partial differential equations of groundwater flow (FEWA) and of solute movement (FEMA). The particular features of FEWA and FEMA are their versatility and flexibility for dealing with nearly all vertically integrated two-dimensional problems. The models were verified against both analytical solutions and widely used US Geological Survey finite difference approximations. They were then applied for calibration and validation, using data obtained in experiments at the Engineering Test Facility at Oak Ridge National Laboratory. Results indicated that the models are valid for this specific site. To demonstrate the versatility anf flexibility of the models, they were applied to two hypothetical, but realistic, complex problems and three field sites across the United States. In these applications the models yielded good agreement with the field data for all three sites. Finally, the predictive capabilities of the models were demonstrated using data obtained at the Hialeah Preston site in Florida. This case illustrates the capability of FEWA and FEMA as predictive tools and their usefulness in the management of groundwater flow and contaminant transport. 25 refs

  8. Inspection and monitoring plan, contaminated groundwater seeps 317/319/ENE Area, Argonne National Laboratory

    International Nuclear Information System (INIS)

    1996-01-01

    During the course of completing the Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) in the 317/319/East-Northeast (ENE) Area of Argonne National Laboratory-East (ANL-E), groundwater was discovered moving to the surface through a series of groundwater seeps. The seeps are located in a ravine approximately 600 ft south of the ANL-E fence line in Waterfall Glen Forest Preserve. Samples of the seep water were collected and analyzed for selected parameters. Two of the five seeps sampled were found to contain detectable levels of organic contaminants. Three chemical species were identified: chloroform (14--25 microg/L), carbon tetrachloride (56--340 microg/L), and tetrachloroethylene (3--6 microg/L). The other seeps did not contain detectable levels of volatile organics. The nature of the contaminants in the seeps will also be monitored on a regular basis. Samples of surface water flowing through the bottom of the ravine and groundwater emanating from the seeps will be collected and analyzed for chemical and radioactive constituents. The results of the routine sampling will be compared with the concentrations used in the risk assessment. If the concentrations exceed those used in the risk assessment, the risk calculations will be revised by using the higher numbers. This revised analysis will determine if additional actions are warranted

  9. Determination of protection zones for Dutch groundwater wells against virus contamination--uncertainty and sensitivity analysis.

    Science.gov (United States)

    Schijven, J F; Mülschlegel, J H C; Hassanizadeh, S M; Teunis, P F M; de Roda Husman, A M

    2006-09-01

    Protection zones of shallow unconfined aquifers in The Netherlands were calculated that allow protection against virus contamination to the level that the infection risk of 10(-4) per person per year is not exceeded with a 95% certainty. An uncertainty and a sensitivity analysis of the calculated protection zones were included. It was concluded that protection zones of 1 to 2 years travel time (206-418 m) are needed (6 to 12 times the currently applied travel time of 60 days). This will lead to enlargement of protection zones, encompassing 110 unconfined groundwater well systems that produce 3 x 10(8) m3 y(-1) of drinking water (38% of total Dutch production from groundwater). A smaller protection zone is possible if it can be shown that an aquifer has properties that lead to greater reduction of virus contamination, like more attachment. Deeper aquifers beneath aquitards of at least 2 years of vertical travel time are adequately protected because vertical flow in the aquitards is only 0.7 m per year. The most sensitive parameters are virus attachment and inactivation. The next most sensitive parameters are grain size of the sand, abstraction rate of groundwater, virus concentrations in raw sewage and consumption of unboiled drinking water. Research is recommended on additional protection by attachment and under unsaturated conditions.

  10. A compositional multiphase model for groundwater contamination by petroleum products: 2. Numerical solution

    Science.gov (United States)

    Baehr, Arthur L.; Corapcioglu, M. Yavuz

    1987-01-01

    In this paper we develop a numerical solution to equations developed in part 1 (M. Y. Corapcioglu and A. L. Baehr, this issue) to predict the fate of an immiscible organic contaminant such as gasoline in the unsaturated zone subsequent to plume establishment. This solution, obtained by using a finite difference scheme and a method of forward projection to evaluate nonlinear coefficients, provides estimates of the flux of solubilized hydrocarbon constituents to groundwater from the portion of a spill which remains trapped in a soil after routine remedial efforts to recover the product have ceased. The procedure was used to solve the one-dimensional (vertical) form of the system of nonlinear partial differential equations defining the transport for each constituent of the product. Additionally, a homogeneous, isothermal soil with constant water content was assumed. An equilibrium assumption partitions the constituents between air, water, adsorbed, and immiscible phases. Free oxygen transport in the soil was also simulated to provide an upper bound estimate of aerobic biodgradation rates. Results are presented for a hypothetical gasoline consisting of eight groups of hydrocarbon constituents. Rates at which hydrocarbon mass is removed from the soil, entering either the atmosphere or groundwater, or is biodegraded are presented. A significant sensitivity to model parameters, particularly the parameters characterizing diffusive vapor transport, was discovered. We conclude that hydrocarbon solute composition in groundwater beneath a gasoline contaminated soil would be heavily weighted toward aromatic constituents like benzene, toluene, and xylene.

  11. Biochar- and phosphate-induced immobilization of heavy metals in contaminated soil and water: implication on simultaneous remediation of contaminated soil and groundwater.

    Science.gov (United States)

    Liang, Yuan; Cao, Xinde; Zhao, Ling; Arellano, Eduardo

    2014-03-01

    Long-term wastewater irrigation or solid waste disposal has resulted in the heavy metal contamination in both soil and groundwater. It is often separately implemented for remediation of contaminated soil or groundwater at a specific site. The main objective of this study was to demonstrate the hypothesis of simultaneous remediation of both heavy metal contaminated soil and groundwater by integrating the chemical immobilization and pump-and-treat methods. To accomplish the objective, three experiments were conducted, i.e., an incubation experiment was first conducted to determine how dairy-manure-derived biochar and phosphate rock tailing induced immobilization of Cd in the Cd-contaminated soils; second, a batch sorption experiment was carried out to determine whether the pre-amended contaminated soil still had the ability to retain Pb, Zn and Cd from aqueous solution. BCR sequential extraction as well as XRD and SEM analysis were conducted to explore the possible retention mechanism; and last, a laboratory-scale model test was undertaken by leaching the Pb, Zn, and Cd contaminated groundwater through the pre-amended contaminated soils to demonstrate how the heavy metals in both contaminated soil and groundwater were simultaneously retained and immobilized. The incubation experiment showed that the phosphate biochar were effective in immobilizing soil Cd with Cd concentration in TCLP (toxicity characteristics leaching procedure) extract reduced by 19.6 % and 13.7 %, respectively. The batch sorption experiment revealed that the pre-amended soil still had ability to retain Pb, Zn, and Cd from aqueous solution. The phosphate-induced metal retention was mainly due to the metal-phosphate precipitation, while both sorption and precipitation were responsible for the metal stabilization in the biochar amendment. The laboratory-scale test demonstrated that the soil amended with phosphate removed groundwater Pb, Zn, and Cd by 96.4 %, 44.6 %, and 49.2 %, respectively, and the

  12. 18O isotopic characterisation of non-point source contributed heavy metals (Zn and Cu) contamination of groundwater

    International Nuclear Information System (INIS)

    Datta, P.S.; Manjaiah, K.M.; Tyagi, S.K.

    1999-01-01

    In many urbanised areas, fast depletion and severe degradation of the of groundwater resource with contaminants such as nitrate, fluoride, and heavy metals is a common phenomenon, resulting in zonal disparity in fresh water availability. Therefore, for protection of groundwater from pollution and depletion, it is a matter of concern for the planners and decision makers to clearly characterise the sources of contamination and to search for an alternative approach for groundwater development and management. In this context, a new approach is presented here, based on monitoring of 18 O stable isotopic and heavy metals composition of groundwater, to clearly characterise non-point source contributed heavy metals pollution of groundwater in northern parts of Delhi area. In the investigated area, the Cu content in the groundwater ranges from 3-41 μg/l and Zn content ranges from 5-182 μg/l, showing considerable variation from location to location as well as within the small parts of a location. Wide variation in the 18 O stable isotope content of groundwater (δ value of -5.7 per mille to -8.5 per mille) is due to significant variation in the δ 18 O-contents of rainfall with space and time, as well as intensity and distribution of rainfall. Enrichment in 18 O composition with increasing Cu and Zn levels in groundwater suggest that infiltration of rain water, irrigation water and surface run-off water from the surrounding farm lands, along with agrochemicals and other salts present in the soil, to be the main processes causing groundwater contamination. The concentration of Cu and Zn in groundwater vary spatially, due to different degrees of evaporation/recharge, amounts of fertiliser applied and wastes disposed, adsorption/dispersion of species in the soils and lateral mixing of groundwater. Two opposite mechanisms adsorption and redistribution of infiltrating water along with Zn and Cu species in the soil zone are likely to affect the movement of the Zn and Cu species

  13. A Review of Groundwater Arsenic Contamination in Bangladesh: The Millennium Development Goal Era and Beyond.

    Science.gov (United States)

    Yunus, Fakir Md; Khan, Safayet; Chowdhury, Priyanka; Milton, Abul Hasnat; Hussain, Sumaira; Rahman, Mahfuzar

    2016-02-15

    Arsenic contamination in drinking water has a detrimental impact on human health which profoundly impairs the quality of life. Despite recognition of the adverse health implications of arsenic toxicity, there have been few studies to date to suggest measures that could be taken to overcome arsenic contamination. After the statement in 2000 WHO Bulletin that Bangladesh has been experiencing the largest mass poisoning of population in history, we researched existing literature to assess the magnitude of groundwater arsenic contamination in Bangladesh. The literature reviewed related research that had been initiated and/or completed since the implementation of the Millennium Development Goals (MDGs) under four domains: (1) extent of arsenic contamination; (2) health consequences; (3) mitigation and technologies and (4) future directions. To this means, a review matrix was established for analysis of previous literature based on these four core domains. Our findings revealed that several high-quality research articles were produced at the beginning of the MDG period, but efforts have dwindled in recent years. Furthermore, there were only a few studies conducted that focused on developing suitable solutions for managing arsenic contamination. Although the government of Bangladesh has made its population's access to safe drinking water a priority agenda item, there are still pockets of the population that continue to suffer from arsenic toxicity due to contaminated water supplies.

  14. Assessment of groundwater contamination risk in an agricultural area in north Italy

    Directory of Open Access Journals (Sweden)

    Georgios Bartzas

    2015-09-01

    Full Text Available In the present study a specific approach is followed, considering the Pesticide DRASTIC and Susceptibility index (SI methods and a GIS framework, to assess groundwater vulnerability in the agricultural area of Albenga, in north Italy. The results indicate “high” to “very high” vulnerability to groundwater contamination along the coastline and the middle part of the Albenga plain, for almost 49% and 56% of the total study area for Pesticide DRASTIC and SI methods, respectively. These sensitive regions depict characteristics such as shallow depth to groundwater, extensive deposits of alluvial silty clays, flat topography and intensive agricultural activities. The distribution of nitrates concentration in groundwater in the study area is slightly better correlated with the SI (0.728 compared to Pesticide DRASTIC (0.693, thus indicating that both methods are characterized by quite good accuracy. Sensitivity analysis was also performed to acknowledge statistical uncertainty in the estimation of each parameter used, assess its impact and thus identify the most critical parameters that require further investigation in the future. Depth to water is the parameter that exhibited the largest impact on the Pesticide DRASTIC vulnerability index followed by the impact of the vadose zone and topography. On the other hand, the SI method is more sensitive to the removal of the topography parameter followed by the aquifer media and the depth to water parameters.

  15. The discharge of nitrate-contaminated groundwater from developed shoreline to marsh-fringed estuary

    Science.gov (United States)

    Portnoy, J.W.; Nowicki, B.L.; Roman, C.T.; Urish, D.W.

    1998-01-01

    As residential development, on-site wastewater disposal, and groundwater contamination increase in the coastal zone, assessment of nutrient removal by soil and sedimentary processes becomes increasingly important. Nitrogen removal efficiency depends largely on the specific flow paths taken by groundwater as it discharges into nitrogen-limited estuarine waters. Shoreline salinity surveys, hydraulic studies, and thermal infrared imagery indicated that groundwater discharge into the Nauset Marsh estuary (Eastham, Massachusetts) occurred in high-velocity seeps immediately seaward of the upland-fringing salt marsh. Discharge was highly variable spatially and occurred through permeable, sandy sediments during low tide. Seepage chamber monitoring showed that dissolved inorganic nitrogen (principally nitrate) traversed nearly conservatively from the aquifer through shallow estuarine sediments to coastal waters at flux rates of 1–3 mmol m−2 h−1. A significant relationship between pore water NO3-N concentrations and NO3-N flux rates may provide a rapid method of estimating nitrogen loading from groundwater to the water column.

  16. Leachable 226Ra in Philippine phosphogypsum and its implication in groundwater contamination in Isabel, Leyte Philippines

    International Nuclear Information System (INIS)

    Canete, Socrates Jose P.; Palad, Lorna Jean H.; Enriquez, Eliza B.; Garcia, Teofilo Y.; Yulo-Nazarea, Teresa

    2007-01-01

    Phosphogypsum (PG), the major waste material in phosphate fertilizer processing, has been known to contain enhanced levels of naturally-occurring radionuclides especially 226 Ra. The lack of radioactivity data regarding Philippine phosphogypsum and its environmental behavior in the Philippine setting has brought concern on possible contamination of groundwater beneath the phosphogypsum ponds in Isabel, Leyte, Philippines. The radioactivity of Philippine phosphogypsum was determined and the leaching of 226 Ra from phosphogypsum and through local soil was quantified. Level of 226 Ra in groundwater samples in Isabel, Leyte, Philippines was also quantified to address the primary concern. It was found that the 226 Ra activity in Philippine phosphogypsum is distributed in a wide range from 91.5 to 935 Bq/kg. As much as 5% of 226 Ra can be leached from Philippine PG with deionized water. In vitro soil leach experiments suggest that the soil in the phosphate fertilizer plant area would be able to deter the intrusion of 226 Ra into the water table. Compared to reported values of natural groundwater levels of 226 Ra, the concentration of this radionuclide in Isabel, Leyte groundwater suggest that there is no 226 Ra intrusion brought about by the presence of phosphogypsum ponds in the area. (Authors)

  17. Laboratory study on sequenced permeable reactive barrier remediation for landfill leachate-contaminated groundwater

    International Nuclear Information System (INIS)

    Dong Jun; Zhao Yongsheng; Zhang Weihong; Hong Mei

    2009-01-01

    Permeable reactive barrier (PRB) was a promising technology for groundwater remediation. Landfill leachate-polluted groundwater riches in various hazardous contaminants. Two lab-scale reactors (reactors A and B) were designed for studying the feasibility of PRB to remedy the landfill leachate-polluted groundwater. Zero valent iron (ZVI) and the mixture of ZVI and zeolites constitute the first section of the reactors A and B, respectively; the second section of two reactors consists of oxygen releasing compounds (ORCs). Experimental results indicated that BOD 5 /COD increased from initial 0.32 up to average 0.61 and 0.6 through reactors A and B, respectively. Removal efficiency of mixed media for pollutants was higher than that of single media (ZVI only). Zeolites exhibited selective removal of Zn, Mn, Mg, Cd, Sr, and NH 4 + , and removal efficiency was 97.2%, 99.6%, 95.9%, 90.5% and 97.4%, respectively. The maximum DO concentration of reactors A and B were 7.64 and 6.78 mg/L, respectively, while the water flowed through the ORC. Therefore, sequenced PRB system was effective and was proposed as an alternative method to remedy polluted groundwater by landfill leachate

  18. Remediation of groundwater contaminated by exa valent chromium. Part 1.: Treatment technologies

    International Nuclear Information System (INIS)

    Sbaffoni, S.; Vaccari, M.

    2009-01-01

    Chromium compounds have been used in several industrial activities and they are often found in soil and groundwater of former industrial sites. Chromium exists in various oxidation states, but the trivalent and hexavalent oxidation ones are of major environmental concern due to their stability in the environment. In particular, Cr(V I) is highly soluble and mobile and is very toxic with mutagenic and carcinogenic effects. The present paper describes the main chemical, physical and toxicological properties of Cr(V I), its fate in the subsoil and both the conventional and innovative technologies for its removal from contaminated groundwater. The paper includes also a brief description of few interesting foreign case studies. [it

  19. Biosensor-based diagnostics of contaminated groundwater: assessment and remediation strategy

    International Nuclear Information System (INIS)

    Bhattacharyya, Jessica; Read, David; Amos, Sean; Dooley, Stephen; Killham, Kenneth; Paton, Graeme I.

    2005-01-01

    Shallow groundwater beneath a former airfield site in southern England has been heavily contaminated with a wide range of chlorinated solvents. The feasibility of using bacterial biosensors to complement chemical analysis and enable cost-effective, and focussed sampling has been assessed as part of a site evaluation programme. Five different biosensors, three metabolic (Vibrio fischeri, Pseudomonas fluorescens 10568 and Escherichia coli HB101) and two catabolic (Pseudomonas putida TVA8 and E. coli DH5α), were employed to identify areas where the availability and toxicity of pollutants is of most immediate environmental concern. The biosensors used showed different sensitivities to each other and to the groundwater samples tested. There was generally a good agreement with chemical analyses. The potential efficacy of remediation strategies was explored by coupling sample manipulation to biosensor tests. Manipulation involved sparging and charcoal treatment procedures to simulate remediative engineering solutions. Sparging was sufficient at most locations. - Luminescent bacteria complement chemical analysis and support remediation technology

  20. Groundwater contamination with 2,6-dichlorobenzamide (BAM) and perspectives for its microbial removal

    DEFF Research Database (Denmark)

    Ellegaard-Jensen, Lea; Horemans, Benjamin; Raes, Bart

    2017-01-01

    (DWTP); therefore, if concentrations exceed the legal threshold limit, it represents a sizeable problem for the stability and quality of drinking water production, especially in places that depend on groundwater for drinking water. Bioremediation is suggested as a valuable strategy for removing BAM from...... groundwater by deploying dedicated BAM-degrading bacteria in DWTP sand filters. Only a few bacterial strains with the capability to degrade BAM have been isolated, and of these, only three isolates belonging to the Aminobacter genus are able to mineralise BAM. Considerable effort has been made to elucidate...... status and knowledge with regard to the application of microorganisms for purification of BAM-contaminated water resources. This paper discusses the prospects and challenges for bioaugmentation of DWTP sand filters with specific BAM-degrading bacteria and identifies relevant perspectives for future...

  1. Risk assessing heavy metals in the groundwater-surface water interface at a contaminated site

    DEFF Research Database (Denmark)

    Bigi, Giovanni; McKnight, Ursula S.; Bjerg, Poul Løgstrup

    such as surface water and groundwater (EC, 2017). The current study quantified and assessed the contamination of As, Cd, Cr, Cu, Ni, Pb and Zn in the shallow aquifer, hyporheic zone, stream water and streambed sediments at Rådvad site, a former metal manufacturing industrial area located in Denmark, investigating...... in the soil). Stream water was sampled in 12 points, while groundwater was sampled in 4 wells close to the stream where the interaction was suspected. Sediments and hyporheic zone were sampled in pair, where upward hydraulic heads have been detected. A drain discharging in the river was also sampled....... Sediments were divided in different layers and both heavy metal total concentration and chemical partitioning were analysed. Redox species and dissolved organic matter were also analysed in the water samples, while fraction of organic carbon was investigated in the extracted sediments. Results showed a high...

  2. Permeable sorptive walls for treatment of hydrophobic organic contaminant plumes in groundwater

    International Nuclear Information System (INIS)

    Grathwohl, P.; Peschik, G.

    1997-01-01

    Highly hydrophobic contaminants are easily adsorbed from aqueous solutions. Since for many of these compounds sorption increases with increasing organic carbon content natural materials such as bituminous shales and coals may be used in permeable sorptive walls. This, however, only applies if sorption is at equilibrium, which may not always be the case in groundwater treatment using a funnel-and-gate system. In contrast to the natural solids, granular activated carbons (GACs) have very high sorption capacities and reasonably fast sorption kinetics. The laboratory results show that application of GACs (e.g. F100) is economically feasible for in situ removal of polycyclic aromatic hydrocarbons (PAH) from groundwater at a former manufactured gas plant site (MGP). For less sorbing compounds (such as benzene, toluene, xylenes) a combination of adsorption and biodegradation is necessary (i.e. sorptive + reactive treatment)

  3. Sources, migration and transformation of antimony contamination in the water environment of Xikuangshan, China: Evidence from geochemical and stable isotope (S, Sr) signatures

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Bing [Geological Survey, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); Zhou, Jianwei, E-mail: jw.zhou@cug.edu.cn [School of Environmental Studies, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); Zhou, Aiguo; Liu, Cunfu [School of Environmental Studies, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); Xie, Lina [School of Environmental Studies, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China)

    2016-11-01

    The Xikuangshan (XKS) mine in central China is the largest antimony (Sb) mine in the world. The mining activity has seriously contaminated the waters in the area. To determine the sources, migration and transformation of Sb contamination, 32 samples from groundwater (aquifer water), surface water and mine water were collected for water chemistry, trace element and S{sub SO4} and Sr stable isotope analyses. The results showed that the groundwater and surface water were in an oxidized environment. The S{sub SO4} and Sr isotope compositions in the water indicated that dissolved Sb and SO{sub 4}{sup 2} originated from sulfide mineral (Sb{sub 2}S{sub 3}) oxidation, whereas radiogenic Sr may have been sourced from silicified limestone and stibnite in the Shetianqiao aquifer. Furthermore, a positive correlation between δ{sup 34}S{sub SO4} and δ{sup 87}Sr values revealed that the Sr, S and Sb in the waters had a common contamination source, i.e., silicified limestone and stibnite, whereas the Sr, S and Sb in rock and ore were sourced from Proterozoic basement clastics. The analysis also indicated that the isotope composition of dissolved SO{sub 4}{sup 2} {sup −} had been influenced by slight bacterial SO{sub 4} reduction in the Magunao aquifer. Mining or rock collapse may have caused Shetianqiao aquifer water to contaminate the Magunao aquifer water via mixing. This study has demonstrated that the stable isotopes of {sup 34}S{sub SO4} and {sup 87}Sr, combined with hydrochemical methods, are effective in tracking the sources, migration and transformation of Sb contamination. - Highlights: • Mining activities at XKS mine have caused serious water contamination. • The characteristics of Sb contamination in water environment are still unclear. • Combine S isotopes of sulfate and Sr isotopes with hydrochemical methods. • Sr, S, and Sb in natural water had a common source: silicified limestone and stibnite. • Shetianqiao aquifer water contaminated the Magunao

  4. Effect of contaminant concentration on in situ bacterial sulfate reduction and methanogenesis in phenol-contaminated groundwater

    International Nuclear Information System (INIS)

    Baker, Kieran M.; Bottrell, Simon H.; Thornton, Steven F.; Peel, Kate E.; Spence, Michael J.

    2012-01-01

    The availability of dissolved O 2 can limit biodegradation of organic compounds in aquifers. Where O 2 is depleted, biodegradation proceeds via anaerobic processes, including NO 3 -, Mn(IV)-, Fe(III)- and SO 4 -reduction and fermentation/methanogenesis. The environmental controls on these anaerobic processes must be understood to support implementation of management strategies such as monitored natural attenuation (MNA). In this study stable isotope analysis is used to show that the relative significance of two key anaerobic biodegradation processes (bacterial SO 4 reduction (BSR) and methanogenesis) in a phenol-contaminated sandstone aquifer is sensitive to spatial and temporal changes in total dissolved phenols concentration (TPC) (= phenol + cresols + dimethylphenols) over a 5-a period. In general, 34 SO 4 -enrichment (characteristic of bacterial SO 4 reduction) is restricted spatially to locations where TPC −1 . In contrast, 13 C-depleted CH 4 and 13 C-enriched CO 2 isotope compositions (characteristic of methanogenesis) were measured at TPC up to 8000 mg L −1 . This is consistent with previous studies that demonstrate suppression of BSR at TPC of >500 mg L −1 , and suggests that methanogenic microorganisms may have a higher tolerance for TPC in this contaminant plume. It is concluded that isotopic enrichment trends can be used to identify conditions under which in situ biodegradation may be limited by the properties of the biodegradation substrate (in this case TPC). Such data may be used to deduce the performance of MNA for contaminated groundwater in similar settings.

  5. Application of Biostimulation for Remediation of Sulfate-Contaminated Groundwater at a Mining Site

    Science.gov (United States)

    Miao, Z.; Carroll, K. C.; Carreon, C.; Brusseau, M. L.

    2011-12-01

    There is growing concern regarding sulfate contamination of groundwater. One innovative in-situ remediation option under investigation is biostimulation through addition of electron-donor amendments to enhance sulfate reduction. Two pilot-scale ethanol-injection tests were conducted at a former uranium mining site that is contaminated with sulfate and nitrate (with a lack of heavy metals), and for which there appears to be minimal natural attenuation of sulfate. The first test was a push-pull test that had a limited zone of influence, while the second test was a single-well injection test in which additional downgradient wells were monitored. For both tests, sulfate concentrations began to decline within a few weeks of injection, after nitrate concentrations were significantly reduced. Concomitantly, aqueous concentrations of manganese, iron, and hydrogen sulfide increased from background. Monitoring over many months revealed that the declines in sulfate concentration conformed to exponential decay, with first-order decay rates of approximately 0.01 /d. Analysis of sulfur stable isotope data indicated that the decrease in sulfate concentrations was microbially mediated. The results also indicated that sulfides formed during sulfate reduction may have undergone partial re-oxidation. This study illustrates the feasibility of using ethanol injection for remediation of sulfate-contaminated groundwater. However, re-oxidation of sulfides (both metal sulfide precipitates and hydrogen sulfide gas) is a potential issue of significance that would need to be addressed.

  6. Arsenicosis, possibly from contaminated groundwater, associated with noncirrhotic intrahepatic portal hypertension.

    Science.gov (United States)

    Goel, Ashish; Christudoss, Pamela; George, Renu; Ramakrishna, Banumathi; Amirtharaj, G Jayakumar; Keshava, Shyamkumar N; Ramachandran, Anup; Balasubramanian, K A; Mackie, Ian; Fleming, Jude J; Elias, Elwyn; Eapen, Chundamannil E

    2016-05-01

    Idiopathic noncirrhotic intrahepatic portal hypertension (NCIPH), a chronic microangiopathy of the liver caused by arsenicosis from use of contaminated groundwater, was reported from Asia. This study aimed to see, if in the twenty-first century, arsenicosis was present in NCIPH patients at our hospital and, if present, to look for groundwater contamination by arsenic in their residential locality. Twenty-seven liver biopsy proven NCIPH patients, 25 portal hypertensive controls with hepatitis B or C related cirrhosis and 25 healthy controls, matched for residential locality, were studied. Eighty-four percent to 96 % of study subjects belonged to middle or lower socioeconomic category. Arsenicosis was looked for by estimation of arsenic levels in finger/toe nails and by skin examination. Arsenic levels in nails and in ground water (in NCIPH patients with arsenicosis) was estimated by mass spectrometry. Nail arsenic levels were raised in five (10 %) portal hypertensive study subjects [two NCIPH patients (both had skin arsenicosis) and three portal hypertensive controls]. All of these five patients were residents of West Bengal or Bangladesh. Skin arsenicosis was noted in three NCIPH patients (11 %) compared to none of disease/healthy controls. Ground water from residential locality of one NCIPH patient with arsenicosis (from Bangladesh) showed extremely high level of arsenic (79.5 μg/L). Arsenicosis and microangiopathy of liver, possibly caused by environmental contamination continues in parts of Asia. Further studies are needed to understand the mechanisms of such 'poverty-linked thrombophilia'.

  7. Modeling Contamination Migration on the Chandra X-ray Observatory II

    Science.gov (United States)

    O'Dell, Steve; Swartz, Doug; Tice, Neil; Plucinsky, Paul; Grant, Catherine; Marshall, Herman; Vikhlinin, Alexey

    2013-01-01

    During its first 14 years of operation, the cold (about -60degC) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition may have changed, perhaps partially related to changes in the operating temperature of the ACIS housing. This evolution of the accumulation of the molecular contamination has motivated further analysis of contamination migration on the Chandra X-ray Observatory, particularly within and near the ACIS cavity. To this end, the current study employs a higher-fidelity geometric model of the ACIS cavity, detailed thermal modeling based upon monitored temperature data, and an accordingly refined model of the molecular transport.

  8. Occurrence of perchloroethylene in surface water and fish in a river ecosystem affected by groundwater contamination.

    Science.gov (United States)

    Wittlingerová, Zdena; Macháčková, Jiřina; Petruželková, Anna; Zimová, Magdalena

    2016-03-01

    Long-term monitoring of the content of perchloroethylene (PCE) in a river ecosystem affected by groundwater contamination was performed at a site in the Czech Republic. The quality of surface water was monitored quarterly between 1994 and 2013, and fish were collected from the affected ecosystem to analyse the content of PCE in their tissue in 1998, 2011 and 2012. Concentrations of PCE (9-140 μg/kg) in the tissue of fish collected from the contaminated part of the river were elevated compared to the part of the river unaffected by the contamination (ND to 5 μg/kg PCE). The quality of surface water has improved as a result of groundwater remediation during the evaluated period. Before the remedial action, PCE concentrations ranged from 30 to 95 μg/L (1994-1997). Following commencement of remedial activities in September 1997, a decrease in the content of PCE in the surface water to 7.3 μg/L (1998) and further to 1 μg/L (2011) and 1.1 μg/L (2012) led to a progressive decrease in the average concentration of PCE in the fish muscle tissue from 79 μg/kg (1998) to 24 (2011) and 30 μg/kg (2012), respectively. It was determined that the bioconcentration of PCE does not have a linear dependence because the decrease in contamination in the fish muscle tissue is not directly proportional to the decrease in contamination in the river water. The observed average bioconcentration factors were 24 and 28 for the lower concentrations of PCE and 11 for the higher concentrations of PCE in the river. In terms of age, length and weight of the collected fish, weight had the greatest significance for bioconcentration, followed by the length, with age being evaluated as a less significant factor.

  9. Alternative Endpoints and Approaches for the Remediation of Contaminated Groundwater at Complex Sites - 13426

    Energy Technology Data Exchange (ETDEWEB)

    Deeb, Rula A.; Hawley, Elisabeth L. [ARCADIS, U.S., 2000 Powell St., 7th Floor, Emeryville, California 94608 (United States)

    2013-07-01

    The goal of United States (U.S.) Department of Energy's (DOE)'s environmental remediation programs is to restore groundwater to beneficial use, similar to many other Federal and state environmental cleanup programs. Based on past experience, groundwater remediation to pre-contamination conditions (i.e., drinking water standards or non-detectable concentrations) can be successfully achieved at many sites. At a subset of the most complex sites, however, complete restoration is not likely achievable within the next 50 to 100 years using today's technology. This presentation describes several approaches used at complex sites in the face of these technical challenges. Many complex sites adopted a long-term management approach, whereby contamination was contained within a specified area using active or passive remediation techniques. Consistent with the requirements of their respective environmental cleanup programs, several complex sites selected land use restrictions and used risk management approaches to accordingly adopt alternative cleanup goals (alternative endpoints). Several sites used long-term management designations and approaches in conjunction with the alternative endpoints. Examples include various state designations for groundwater management zones, technical impracticability (TI) waivers or greater risk waivers at Superfund sites, and the use of Monitored Natural Attenuation (MNA) or other passive long-term management approaches over long time frames. This presentation will focus on findings, statistics, and case studies from a recently-completed report for the Department of Defense's Environmental Security Technology Certification Program (ESTCP) (Project ER-0832) on alternative endpoints and approaches for groundwater remediation at complex sites under a variety of Federal and state cleanup programs. The primary objective of the project was to provide environmental managers and regulators with tools, metrics, and information needed

  10. Alternative Endpoints and Approaches for the Remediation of Contaminated Groundwater at Complex Sites - 13426

    International Nuclear Information System (INIS)

    Deeb, Rula A.; Hawley, Elisabeth L.

    2013-01-01

    The goal of United States (U.S.) Department of Energy's (DOE)'s environmental remediation programs is to restore groundwater to beneficial use, similar to many other Federal and state environmental cleanup programs. Based on past experience, groundwater remediation to pre-contamination conditions (i.e., drinking water standards or non-detectable concentrations) can be successfully achieved at many sites. At a subset of the most complex sites, however, complete restoration is not likely achievable within the next 50 to 100 years using today's technology. This presentation describes several approaches used at complex sites in the face of these technical challenges. Many complex sites adopted a long-term management approach, whereby contamination was contained within a specified area using active or passive remediation techniques. Consistent with the requirements of their respective environmental cleanup programs, several complex sites selected land use restrictions and used risk management approaches to accordingly adopt alternative cleanup goals (alternative endpoints). Several sites used long-term management designations and approaches in conjunction with the alternative endpoints. Examples include various state designations for groundwater management zones, technical impracticability (TI) waivers or greater risk waivers at Superfund sites, and the use of Monitored Natural Attenuation (MNA) or other passive long-term management approaches over long time frames. This presentation will focus on findings, statistics, and case studies from a recently-completed report for the Department of Defense's Environmental Security Technology Certification Program (ESTCP) (Project ER-0832) on alternative endpoints and approaches for groundwater remediation at complex sites under a variety of Federal and state cleanup programs. The primary objective of the project was to provide environmental managers and regulators with tools, metrics, and information needed to evaluate

  11. Groundwater contamination and risk assessment of industrial complex in Busan Metropolitan City, Korea

    Science.gov (United States)

    Hamm, S.-Y.; Ryu, S. M.; Cheong, J.-Y.; Woo, Y.-J.

    2003-04-01

    In Korea, the potential of groundwater contamination in urban areas is increasing by industrial and domestic waste waters, leakage from oil storage tanks and sewage drains, leachate from municipal landfill sites and so on. Nowadays, chlorinated organic compounds such as trichloroethylene (TCE) and tetrachloroethylene (PCE), which are driving residential area as well as industrial area, are recognized as major hazardous contaminants. As well known, TCE is wisely used industrial activities such as degreasing, metal stripping, chemical manufacturing, pesticide production, coal gasification plants, creosote operation, and also used in automobile service centers, photo shops and laundries as cleaning solvent. Thus, groundwater protection in urban areas is important issue in Korea This study is to understand groundwater quality and contamination characteristics and to estimate risk assessment in Sasang industrial complex, Busan Metropolitan City. Busan Metropolitan City is located on southeastern coast of the Korean peninsula and is the second largest city in South Korea with a population of 3.8 millions. The geology of the study area is composed of andesite, andesitic tuff, biotite granite and alluvium (Kim et al., 1998). However, geology cannot be identified on the surface due to pavement and buildings. According to drill logs in the study area, the geologic section consists in landfill, fine sand, clay, gravelly clay, and biotite granite from the surface. Biotite granite appears 5.5- 6 m depth. Groundwater samples were collected at twenty sites in Sasang industrial complex. The groundwater samples are plotted on Piper's trilinear diagram, which indicates Ca-Cl2 type. The groundwater may be influenced by salt water because Sasang industrial complex is located near the mouse of Nakdong river that flows to the South Sea. The Ca-Cl2 water type may be partly influenced by anthropogenic contamination in the study area, since water type in granite area generally belongs Ca

  12. A synoptic summary approach to better understanding groundwater contamination problems and evaluating long-term environmental consequences

    International Nuclear Information System (INIS)

    Nelson, R.W.

    1990-09-01

    A summary approach has been developed within groundwater hydrology to communicate with a broad audience and more completely evaluate the long-term impacts of subsurface contamination problems. This synoptic approach both highlights the dominant features occurring in subsurface contamination problems and emphasizes the information required to determine the long-term environmental impacts. The special merit of a summary approach is in providing a better understanding of subsurface contamination problems to adjoining technical disciplines, public decision makers, and private citizens. 14 refs

  13. Recharge heterogeneity and high intensity rainfall events increase contamination risk for Mediterranean groundwater resources

    Science.gov (United States)

    Hartmann, Andreas; Jasechko, Scott; Gleeson, Tom; Wada, Yoshihide; Andreo, Bartolomé; Barberá, Juan Antonio; Brielmann, Heike; Charlier, Jean-Baptiste; Darling, George; Filippini, Maria; Garvelmann, Jakob; Goldscheider, Nico; Kralik, Martin; Kunstmann, Harald; Ladouche, Bernard; Lange, Jens; Mudarra, Matías; Francisco Martín, José; Rimmer, Alon; Sanchez, Damián; Stumpp, Christine; Wagener, Thorsten

    2017-04-01

    Karst develops through the dissolution of carbonate rock and results in pronounced spatiotemporal heterogeneity of hydrological processes. Karst groundwater in Europe is a major source of fresh water contributing up to half of the total drinking water supply in some countries like Austria or Slovenia. Previous work showed that karstic recharge processes enhance and alter the sensitivity of recharge to climate variability. The enhanced preferential flow from the surface to the aquifer may be followed by enhanced risk of groundwater contamination. In this study we assess the contamination risk of karst aquifers over Europe and the Mediterranean using simulated transit time distributions. Using a new type of semi-distributed model that considers the spatial heterogeneity of karst hydraulic properties, we were able to simulate karstic groundwater recharge including its heterogeneous spatiotemporal dynamics. The model is driven by gridded daily climate data from the Global Land Data Assimilation System (GLDAS). Transit time distributions are calculated using virtual tracer experiments. We evaluated our simulations by independent information on transit times derived from observed time series of water isotopes of >70 karst springs over Europe. The simulations indicate that, compared to humid, mountain and desert regions, the Mediterranean region shows a stronger risk of contamination in Europe because preferential flow processes are most pronounced given thin soil layers and the seasonal abundance of high intensity rainfall events in autumn and winter. Our modelling approach includes strong simplifications and its results cannot easily be generalized but it still highlights that the combined effects of variable climate and heterogeneous catchment properties constitute a strong risk on water quality.

  14. Dual wall reverse circulation drilling with multi-level groundwater sampling for groundwater contaminant plume delineation at Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    Smuin, D.R.; Morti, E.E.; Zutman, J.L.; Pickering, D.A.

    1995-01-01

    Dual wall reverse circulation (DWRC) drilling was used to drill 48 borings during a groundwater contaminant investigation at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky. This method was selected as an alternative to conventional hollow stem auger drilling for a number of reasons, including the expectation of minimizing waste, increasing the drilling rate, and reducing the potential for cross contamination of aquifers. Groundwater samples were collected from several water-bearing zones during drilling of each borehole. The samples were analyzed for volatile organic compounds using a field gas chromatograph. This approach allowed the investigation to be directed using near-real-time data. Use of downhole geophysical logging, in conjunction with lithologic descriptions of borehole cuttings, resulted in excellent correlation of the geology in the vicinity of the contaminant plume. The total volume of cuttings generated using the DWRC drilling method was less than half of what would have been produced by hollow stem augering; however, the cuttings were recovered in slurry form and had to be dewatered prior to disposal. The drilling rate was very rapid, often approaching 10 ft/min; however, frequent breaks to perform groundwater sampling resulted in an average drilling rate of < 1 ft/min. The time required for groundwater sampling could be shortened by changing the sampling methodology. Analytical results indicated that the drilling method successfully isolated the various water bearing zones and no cross contamination resulted from the investigation

  15. Groundwater Contamination

    Science.gov (United States)

    ... Membership Administrative Fees Make A Donation Tools & Resources E Commerce Policies General Payment Methods Shipping & Handling Skip to ... Membership Administrative Fees Make A Donation Tools & Resources E Commerce Policies General Payment Methods Shipping & Handling Donate Potential ...

  16. A Discovery-Based Experiment Illustrating How Iron Metal Is Used to Remediate Contaminated Groundwater

    Science.gov (United States)

    Balko, Barbara A.; Tratnyek, Paul G.

    2001-12-01

    In this article, we describe an experiment for undergraduate general chemistry in which students investigate the chemistry behind iron-permeable reactive barriers (iron PRBs), a new technology that is widely used to remediate contaminated groundwater. Contaminant remediation involving iron PRBs is a redox process: the iron metal undergoes oxidative dissolution while the contaminant is reduced. The reaction is complicated, however, by the fact that it involves a surface that changes owing to the development of a layer of rust (iron oxide) on the iron. In this experiment, students examine the iron PRB-contaminant reaction by characterizing the kinetics of the degradation of a dye (the model contaminant) in the presence of granular iron under various experimental conditions. Students can be asked to design their own experiments to investigate aspects of the degradation reaction that are of particular interest to them. The material covered in the lab includes oxidation-reduction reactions, pseudo first-order kinetics, spectrophotometry, and the application of chemistry to solving environmental problems. The experiment can also be used as a vehicle to introduce more advanced topics in chemistry such as heterogeneous reactions, corrosion, passive film growth, and mass transport.

  17. They all like it hot: faster cleanup of contaminated soil and groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Newmark, R., LLNL

    1998-03-01

    Clean up a greasy kitchen spill with cold water and the going is slow. Us hot water instead and progress improves markedly. So it makes sense that cleanup of greasy underground contaminants such as gasoline might go faster if hot water or steam were somehow added to the process. The Environmental Protection Agency named hundreds of sites to the Superfund list - sites that have been contaminated with petroleum products or petroleum products or solvents. Elsewhere across the country, thousands of properties not identified on federal cleanup lists are contaminated as well. Given that under current regulations, underground accumulations of solvent and hydrocarbon contaminants (the most serious cause of groundwater pollution) must be cleaned up, finding a rapid and effective method of removing them is imperative. In the early 1990`s, in collaboration with the School of Engineering at the University of California at Berkeley, Lawrence Livermore developed dynamic underground stripping. This method for treating underground contaminants with heat is much faster and more effective than traditional treatment methods.

  18. Groundwater contamination from waste management sites: The interaction between risk-based engineering design and regulatory policy: 1. Methodology

    Science.gov (United States)

    Massmann, Joel; Freeze, R. Allan

    1987-02-01

    This paper puts in place a risk-cost-benefit analysis for waste management facilities that explicitly recognizes the adversarial relationship that exists in a regulated market economy between the owner/operator of a waste management facility and the government regulatory agency under whose terms the facility must be licensed. The risk-cost-benefit analysis is set up from the perspective of the owner/operator. It can be used directly by the owner/operator to assess alternative design strategies. It can also be used by the regulatory agency to assess alternative regulatory policy, but only in an indirect manner, by examining the response of an owner/operator to the stimuli of various policies. The objective function is couched in terms of a discounted stream of benefits, costs, and risks over an engineering time horizon. Benefits are in the form of revenues for services provided; costs are those of construction and operation of the facility. Risk is defined as the cost associated with the probability of failure, with failure defined as the occurrence of a groundwater contamination event that violates the licensing requirements established for the facility. Failure requires a breach of the containment structure and contaminant migration through the hydrogeological environment to a compliance surface. The probability of failure can be estimated on the basis of reliability theory for the breach of containment and with a Monte-Carlo finite-element simulation for the advective contaminant transport. In the hydrogeological environment the hydraulic conductivity values are defined stochastically. The probability of failure is reduced by the presence of a monitoring network operated by the owner/operator and located between the source and the regulatory compliance surface. The level of reduction in the probability of failure depends on the probability of detection of the monitoring network, which can be calculated from the stochastic contaminant transport simulations. While

  19. Assessment of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

    Science.gov (United States)

    Hult, M.F.

    1984-01-01

    Operation of a coal-tar distillation and wood-preserving facility in St. Louis Park, Minnesota, during 1918-72 contaminated ground water with coal-tar derivatives and inorganic chemicals. Coal-tar derivatives entered the groundwater system through three major paths: (1) Spills and drippings that percolated to the water table, (2) surface runoff and plant process water that was discharged to wetlands south of the former plant site, and (3) movement of coal tar directly into bedrock aquifers through a multiaquifer well on the site.

  20. Groundbreaking technology: in-situ anaerobic bioremediation for treatment of contaminated soil and groundwater

    International Nuclear Information System (INIS)

    Fernandes, K.A.

    2002-01-01

    Anaerobic in-situ bioremediation is a technique often used to cleanse contaminated soil and groundwater. 'Anaerobic in-situ bioremediation' is a phrase with distinct terms all having relevance in the application of this technique. Anaerobic implies the absence of dissolved oxygen, while 'in-situ' simply means that the environmental cleansing occurs with out removing, displacing, or significantly disturbing the specimen or surrounding area. 'Bioremediation' is a term used to describe the biological use of microbes or plants to detoxify the environment. In order to properly implement this complex process, one must have an understanding of microbiology, biochemistry, genetics, metabolic processes, and structure and function of natural microbial communities. (author)

  1. Volatilized tritiated water vapor in the vicinity of exposed tritium contaminated groundwater

    International Nuclear Information System (INIS)

    Dunn, D.L.; Carlton, B.; Hunter, C.; McAdams, T.

    1994-01-01

    Water vapor tritium concentrations in air above a known source of tritiated water can be estimated. Estimates should account for the mechanisms of evaporation and condensation at the water surface and water species exchange, and are typically applicable under a broad range of wind, temperature and humidity conditions. An estimate of volatilized tritium water vapor was made for a known outcropping of tritium contaminated groundwater at the Savannah River Site (SRS) old F-Area effluent stream. In order to validate this estimate and the associated dose calculation, sampling equipment was fabricated, tested, and installed at the effluent stream. The estimate and the dose calculation were confirmed using data from samples collected

  2. Functional gene array-based analysis of microbial community structure in groundwaters with a gradient of contaminant levels

    Energy Technology Data Exchange (ETDEWEB)

    Waldron, P.J.; Wu, L.; Van Nostrand, J.D.; Schadt, C.W.; Watson, D.B.; Jardine, P.M.; Palumbo, A.V.; Hazen, T.C.; Zhou, J.

    2009-06-15

    To understand how contaminants affect microbial community diversity, heterogeneity, and functional structure, six groundwater monitoring wells from the Field Research Center of the U.S. Department of Energy Environmental Remediation Science Program (ERSP; Oak Ridge, TN), with a wide range of pH, nitrate, and heavy metal contamination were investigated. DNA from the groundwater community was analyzed with a functional gene array containing 2006 probes to detect genes involved in metal resistance, sulfate reduction, organic contaminant degradation, and carbon and nitrogen cycling. Microbial diversity decreased in relation to the contamination levels of the wells. Highly contaminated wells had lower gene diversity but greater signal intensity than the pristine well. The microbial composition was heterogeneous, with 17-70% overlap between different wells. Metal-resistant and metal-reducing microorganisms were detected in both contaminated and pristine wells, suggesting the potential for successful bioremediation of metal-contaminated groundwaters. In addition, results of Mantel tests and canonical correspondence analysis indicate that nitrate, sulfate, pH, uranium, and technetium have a significant (p < 0.05) effect on microbial community structure. This study provides an overall picture of microbial community structure in contaminated environments with functional gene arrays by showing that diversity and heterogeneity can vary greatly in relation to contamination.

  3. Development of Real-Time PCR to Monitor Groundwater Contaminated by Fecal Sources and Leachate from the Carcass

    Science.gov (United States)

    Park, S.; Kim, H.; Kim, M.; Lee, Y.; Han, J.

    2011-12-01

    The 2010 outbreak of foot and mouth disease (FMD) in South Korea caused about 4,054 carcass burial sites to dispose the carcasses. Potential environmental impacts by leachate of carcass on groundwater have been issued and it still needs to be studied. Therefore, we tried to develop robust and sensitive tool to immediately determine a groundwater contamination by the leachate from carcass burial. For tracking both an agricultural fecal contamination source and the leachate in groundwater, competitive real-time PCR and PCR method were developed using various PCR primer sets designed to detect E. Coli uidA gene and mtDNA(cytochrome B, cytB) of the animal species such as ovine, porcine, caprine, and bovine. The designed methods were applied to tract the animal species in livestock wastewater and leachate of carcass under appropriate PCR or real-time PCR condition. In the result, mtDNA primer sets for individual (Cow or Pig) and multiple (Cow and Pig) amplification, and E. Coli uidA primers for fecal source amplification were specific and sensitive to target genes. To determine contamination source, concentration of amplified mtDNA and uidA was competitively quantified in Livestock wastewater, leachate of carcass, and groundwater. The highest concentration of mtDNA and uidA showed in leachate of carcass and livestock wastewater, respectively. Groundwater samples possibly contaminated by leachate of carcass were analyzed by this assay and it was able to prove contamination source.

  4. Management of Ground and Groundwater Contamination on a Compact Site Constrained by Ongoing Activities

    International Nuclear Information System (INIS)

    Eilbeck, K.E.; Reeve, P.

    2009-01-01

    Sellafield Site is a compact and complex site which since the 1940's has been home to a range of facilities associated with the production and reprocessing of fissile material. The site contains the UK equivalent of the Chicago Pile-1 reactor, Hanford B Reactor, Rocky Flats Buildings 771 and 774, West Valley Main Process Plant Building, Savannah River Vitrification Plant, Savannah River MOX Plant, Savannah River F Canyon, Hanford 222 Analytical Laboratory, Savannah River K-, L-, and P-Basins, and the Fort St. Vrain Reactor all in an area of approximately 1000 acres. Spent fuel reprocessing is still undertaken on site; however waste management and decommissioning activities are of increasing importance. These include the emptying and removal of fragile ponds and silos containing significant radioactive inventories, the decommissioning of reactors (including the world's first commercial reactor for power generation and the Windscale Piles, the site of a reactor fire in the late 1950's) and the construction of a new generation of vitrification and encapsulation plants. Leaks, spills and on-site disposals during the site's industrial lifetime have resulted in a legacy of fission products and other radionuclides in the ground and groundwater. Volumes of contaminated ground have been estimated as being as much as 18 million m 3 and an estimated below ground inventory of approximately 1.8 E16 Bq. These have all occurred within close proximity to a range of receptors including farm land and the sea. The cramped nature of the facilities on site, overlapping source terms and ongoing decommissioning, waste management and operating activities all raise significant challenges in the management and remediation of contaminated land and groundwater. The strategy to address these challenges includes: 1. Data collection, management and interpretation. The congested nature of the site and the age of some of the monitoring facilities has resulted in particular difficulties. For

  5. In situ groundwater and sediment bioremediation: barriers and perspectives at European contaminated sites.

    Science.gov (United States)

    Majone, Mauro; Verdini, Roberta; Aulenta, Federico; Rossetti, Simona; Tandoi, Valter; Kalogerakis, Nicolas; Agathos, Spiros; Puig, Sebastià; Zanaroli, Giulio; Fava, Fabio

    2015-01-25

    This paper contains a critical examination of the current application of environmental biotechnologies in the field of bioremediation of contaminated groundwater and sediments. Based on analysis of conventional technologies applied in several European Countries and in the US, scientific, technical and administrative barriers and constraints which still need to be overcome for an improved exploitation of bioremediation are discussed. From this general survey, it is evident that in situ bioremediation is a highly promising and cost-effective technology for remediation of contaminated soil, groundwater and sediments. The wide metabolic diversity of microorganisms makes it applicable to an ever-increasing number of contaminants and contamination scenarios. On the other hand, in situ bioremediation is highly knowledge-intensive and its application requires a thorough understanding of the geochemistry, hydrogeology, microbiology and ecology of contaminated soils, groundwater and sediments, under both natural and engineered conditions. Hence, its potential still remains partially unexploited, largely because of a lack of general consensus and public concerns regarding the lack of effectiveness and control, poor reliability, and possible occurrence of side effects, for example accumulation of toxic metabolites and pathogens. Basic, applied and pre-normative research are all needed to overcome these barriers and make in situ bioremediation more reliable, robust and acceptable to the public, as well as economically more competitive. Research efforts should not be restricted to a deeper understanding of relevant microbial reactions, but also include their interactions with the large array of other relevant phenomena, as a function of the truly variable site-specific conditions. There is a need for a further development and application of advanced biomolecular tools for site investigation, as well as of advanced metabolic and kinetic modelling tools. These would allow a

  6. Use of MICRAS code on the evaluation of the maximum radionuclides concentrations due to transport/migration of decay chain in groundwaters

    International Nuclear Information System (INIS)

    Aquino Branco, O.E. de

    1995-01-01

    This paper presents a methodology for the evaluation of the maximum radionuclides concentrations in groundwaters, due to the transport/migration of decay chains. Analytical solution of the equations system is difficult, even if only three elements of the decay chain are considered. Therefore, a numerical solution is most convenient. An application of the MICRAS code, developed to assess maximum concentrations of each radionuclide, starting with the initial concentrations, is presented. The maximum concentration profile for 226 Ra, calculated using MICRAS, is compared with the results obtained through an analytical and a numerical model. The fitness of results is considered good. Simplified models, like the one represented by the application of MICRAS, are largely employed in the section in the selection and characterization of sites for radioactive wastes repositories and in studies of safety evaluation for the same purpose. A detailed analysis of the transport/migration of contaminants in aquifers requires a large quantify of data from the site and from the installation as well, which makes this analysis expensive and inviable during the preliminary phases of the studies. (author). 6 refs, 1 fig, 1 tab

  7. Assessment of groundwater quality and contamination problems ascribed to an abandoned uranium mine (Cunha Baixa region, Central Portugal)

    Science.gov (United States)

    Neves, O.; Matias, M. J.

    2008-02-01

    The assessment of groundwater quality and its environmental implications in the region of the abandoned Cunha Baixa uranium mine (Central Portugal) was carried out from 1995 to 2004. Shallow groundwater is the major water supply source for irrigation in the neighbourhood of Cunha Baixa village. Water samples from the mine site as well as from private wells were collected in order to identify the mining impact on water composition, the extent of contamination and the seasonal and temporal groundwater quality variations. Some of the sampled private wells contain waters having low pH (risks. Nevertheless, this study indicates that groundwater contamination suffered a small decrease from 1999 to 2004. The bioaccumulation of toxic metals such as Al, Mn, and U within the food chain may cause a serious health hazard to the Cunha Baixa village inhabitants.

  8. Microbial Degradation of Phenols and Aromatic Hydrocarbons in Creosote-contaminated Groundwater Under Nitrate-reducing Conditions

    DEFF Research Database (Denmark)

    Flyvbjerg, John; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    of toluene, 2,4-DMP, 3,4-DMP and p-cresol depended on nitrate or nitrite as electron acceptors. 40–80% of the nitrate consumed during degradation of the aromatic compounds was recovered as nitrite, and the consumption of nitrate was accompanied by a production of ATP. Stoichiometric calculations indicated......Batch experiments were carried out to investigate the biodegradation of phenols and aromatic hydrocarbons under anaerobic, nitrate-reducing conditions in groundwater from a creosote-contaminated site at Fredensborg, Denmark. The bacteria in the creosote-contaminated groundwater degraded a mixture...... that in addition to the phenols are toluene other carbon sources present in the groundwater contributed to the consumption of nitrate. If the groundwater was incubated under anaerobic conditions without nitrate, sulphate-reducing conditions evolved after ∼ 1 month at 20°C and ∼2 months at 10°C. In the sulphate...

  9. Remediation of groundwater contaminated with arsenic through enhanced natural attenuation: Batch and column studies.

    Science.gov (United States)

    Hafeznezami, Saeedreza; Zimmer-Faust, Amity G; Jun, Dukwoo; Rugh, Megyn B; Haro, Heather L; Park, Austin; Suh, Jae; Najm, Tina; Reynolds, Matthew D; Davis, James A; Parhizkar, Tarannom; Jay, Jennifer A

    2017-10-01

    Batch and column laboratory experiments were conducted on natural sediment and groundwater samples from a contaminated site in Maine, USA with the aim of lowering the dissolved arsenate [As(V)] concentrations through chemical enhancement of natural attenuation capacity. In batch factorial experiments, two levels of treatment for three parameters (pH, Ca, and Fe) were studied at different levels of phosphate to evaluate their impact on As(V) solubility. Results illustrated that lowering pH, adding Ca, and adding Fe significantly increased the sorption capacity of sediments. Overall, Fe amendment had the highest individual impact on As(V) levels. To provide further evidence for the positive impact of Ca on As(V) adsorption, isotherm experiments were conducted at three different levels of Ca concentrations. A consistent increase in adsorption capacity (26-37%) of sediments was observed with the addition of Ca. The observed favorable effect of Ca on As(V) adsorption is likely caused by an increase in the surface positive charges due to surface accumulation of Ca 2+ ions. Column experiments were conducted by flowing contaminated groundwater with elevated pH, As(V), and phosphate through both uncontaminated and contaminated sediments. Potential in-situ remediation scenarios were simulated by adding a chemical amendment feed to the columns injecting Fe(II) or Ca as well as simultaneous pH adjustment. Results showed a temporary and limited decrease in As(V) concentrations under the Ca treatment (39-41%) and higher levels of attenuation in Fe(II) treated columns (50-91%) but only after a certain number of pore volumes (18-20). This study illustrates the importance of considering geochemical parameters including pH, redox potential, presence of competing ions, and sediment chemical and physical characteristics when considering enhancing the natural attenuation capacity of sediments to mitigate As contamination in natural systems. Copyright © 2017 Elsevier Ltd. All rights

  10. Predicting the risk of groundwater arsenic contamination in drinking water wells

    Science.gov (United States)

    Cao, Hailong; Xie, Xianjun; Wang, Yanxin; Pi, Kunfu; Li, Junxia; Zhan, Hongbin; Liu, Peng

    2018-05-01

    Arsenic (As)-contaminated groundwater is a global concern with potential detrimental effects on the health of hundreds of millions of people worldwide. However, the extent of this problem may be more severe than anticipated, as many wells have not been tested and may contain unsafe-level of As. An optimized statistical regression model was developed to predict the probability of geogenic high As groundwater (As > 10 μg/L) in this study. Easily obtained hydrogeochemical and geological parameters that are significantly related to As geochemical behaviors were selected as explanatory variables in the model. The results indicate that pH, Cl-, HCO3-, SO42-, and NO3- concentrations, stratigraphic information, and well depth are excellent predictors of As exposure in the Datong Basin, China. Predicted unsafe wells correspond well with the known distribution of high As groundwater in the Datong Basin. The successful application of a data set from Bangladesh also demonstrated the applicability and credibility of this proposed method.

  11. In situ treatment of arsenic-contaminated groundwater by air sparging.

    Science.gov (United States)

    Brunsting, Joseph H; McBean, Edward A

    2014-04-01

    Arsenic contamination of groundwater is a major problem in some areas of the world, particularly in West Bengal (India) and Bangladesh where it is caused by reducing conditions in the aquifer. In situ treatment, if it can be proven as operationally feasible, has the potential to capture some advantages over other treatment methods by being fairly simple, not using chemicals, and not necessitating disposal of arsenic-rich wastes. In this study, the potential for in situ treatment by injection of compressed air directly into the aquifer (i.e. air sparging) is assessed. An experimental apparatus was constructed to simulate conditions of arsenic-rich groundwater under anaerobic conditions, and in situ treatment by air sparging was employed. Arsenic (up to 200 μg/L) was removed to a maximum of 79% (at a local point in the apparatus) using a solution with dissolved iron and arsenic only. A static "jar" test revealed arsenic removal by co-precipitation with iron at a molar ratio of approximately 2 (iron/arsenic). This is encouraging since groundwater with relatively high amounts of dissolved iron (as compared to arsenic) therefore has a large theoretical treatment capacity for arsenic. Iron oxidation was significantly retarded at pH values below neutral. In terms of operation, analysis of experimental results shows that periodic air sparging may be feasible. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Capacitive deionization of arsenic-contaminated groundwater in a single-pass mode.

    Science.gov (United States)

    Fan, Chen-Shiuan; Liou, Sofia Ya Hsuan; Hou, Chia-Hung

    2017-10-01

    A single-pass-mode capacitive deionization (CDI) reactor was used to remove arsenic from groundwater in the presence of multiple ions. The CDI reactor involved an applied voltage of 1.2 V and six cell pairs of activated carbon electrodes, each of which was 20 × 30 cm 2 . The results indicate that this method achieved an effluent arsenic concentration of 0.03 mg L -1 , which is lower than the arsenic concentration standard for drinking water and irrigation sources in Taiwan, during the charging stage. Additionally, the ability of the CDI to remove other coexisting ions was studied. The presence of other ions has a significant influence on the removal of arsenic from groundwater. From the analysis of the electrosorption selectivity, the preference for anion removal could be ordered as follows: NO 3 -  > SO 4 2-  > F -  > Cl - >As. The electrosorption selectivity for cations could be ordered as follows: Ca 2+  > Mg 2+  > Na +  ∼ K + . Moreover, monovalent cations can be replaced by divalent cations at the electrode surface in the later period of the electrosorption stage. Consequently, activated carbon-based capacitive deionization is demonstrated to be a high-potential technology for remediation of arsenic-contaminated groundwater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Prediction of uranium and technetium sorption during titration of contaminated acidic groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Fan, E-mail: zhangfan@itpcas.ac.cn [Institute of Tibetan Plateau Research, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing 100085 (China); Parker, Jack C. [Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Brooks, Scott C.; Watson, David B. [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6038 (United States); Jardine, Philip M. [Biosystems Engineering and Soil Science Department, University of Tennessee, Knoxville, TN 37996 (United States); Gu, Baohua [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6038 (United States)

    2010-06-15

    This study investigates uranium and technetium sorption onto aluminum and iron hydroxides during titration of acidic groundwater. The contaminated groundwater exhibits oxic conditions with high concentrations of NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, U, Tc, and various metal cations. More than 90% of U and Tc was removed from the aqueous phase as Al and Fe precipitated above pH 5.5, but was partially resolublized at higher pH values. An equilibrium hydrolysis and precipitation reaction model adequately described variations in aqueous concentrations of metal cations. An anion exchange reaction model was incorporated to simulate sulfate, U and Tc sorption onto variably charged (pH-dependent) Al and Fe hydroxides. Modeling results indicate that competitive sorption/desorption on mixed mineral phases needs to be considered to adequately predict U and Tc mobility. The model could be useful for future studies of the speciation of U, Tc and co-existing ions during pre- and post-groundwater treatment practices.

  14. Field sampling for monitoring, migration and defining the areal extent of chemical contamination

    International Nuclear Information System (INIS)

    Thomas, J.M.; Skalski, J.R.; Eberhardt, L.L.; Simmons, M.A.

    1984-01-01

    As part of two studies funded by the U.S. Nuclear Regulatory Commission and the USEPA, the authors have investigated field sampling strategies and compositing as a means of detecting spills or migration at commercial low-level radioactive and chemical waste disposal sites and bioassays for detecting contamination at chemical waste sites. Compositing (pooling samples) for detection is discussed first, followed by the development of a statistical test to determine whether any component of a composite exceeds a prescribed maximum acceptable level. Subsequently, the authors explore the question of optimal field sampling designs and present the features of a microcomputer program designed to show the difficulties in constructing efficient field designs and using compositing schemes. Finally, they propose the use of bioassays as an adjunct or replacement for chemical analysis as a means of detecting and defining the areal extent of chemical migration

  15. A decade of investigations on groundwater arsenic contamination in Middle Ganga Plain, India.

    Science.gov (United States)

    Saha, Dipankar; Sahu, Sudarsan

    2016-04-01

    Groundwater arsenic (As) load in excess of drinking limit (50 µg L(-1)) in the Gangetic Plains was first detected in 2002. Though the menace was known since about two decades from the downstream part of the plains in the Bengal Basin, comprising of Lower Ganga Plain and deltaic plains of Ganga-Brahmaputra-Meghna River system, little thought was given to its possible threat in the upstream parts in the Gangetic Plains beyond Garo-Rajmahal Hills. The contamination in Bengal Basin has become one of the extensively studied issues in the world and regarded as the severest case of health hazard in the history of mankind. The researches and investigations in the Gangetic Plains during the last decade (2003-2013) revealed that the eastern half of the plains, also referred as Middle Ganga Plain (MGP), is particularly affected by contamination, jeopardising the shallow aquifer-based drinking water supply. The present paper reviews researches and investigations carried out so far in MGP by various research institutes and government departments on wide array of issues of groundwater As such as its spatio-temporal variation, mobilisation paths, water level behaviour and flow regime, configuration of contaminated and safe aquifers and their recharge mechanism. Elevated conc. of groundwater As has been observed in grey and dark grey sediments of Holocene age (Newer Alluvium) deposited in a fluvio-lacustrine environment in the floodplain of the Ganga and most of its northern tributaries from Himalayas. Older Alluvium, comprising Pleistocene brownish yellow sediment, extending as deeper aquifers in Newer Alluvium areas, is low in groundwater As. Similarities and differences on issues between the MGP and the Bengal Basin have been discussed. The researches point towards the mobilisation process as reductive dissolution of iron hydroxide coating, rich in adsorbed As, mediated by microbial processes. The area is marked with shallow water level (<8.0 m below ground) with ample

  16. An interdisciplinary approach for groundwater management in area contaminated by fluoride in East African Rift System

    Science.gov (United States)

    Da Pelo, Stefania; Melis, M. Teresa; Dessì, Francesco; Pistis, Marco; Funedda, Antonio; Oggiano, Giacomo; Carletti, Alberto; Soler Gil, Albert; Barbieri, Manuela; Pittalis, Daniele; Ghiglieri, Giorgio

    2017-04-01

    Groundwater is the main source of fresh water supply for most of the rural communities in Africa (approximately 75% of Africans has confidence in groundwater as their major source of drinking water). Many African countries has affected by high fluoride concentration in groundwater (up to 90 mg/L), generating the contamination of waters, soils and food, in particular in the eastern part of the continent. It seems that fluoride concentration is linked to geology of the Rift Valley: geogenic occurrence of fluoride is often connected to supergenic enrichment due to the weathering of alkaline volcanic rocks, fumaric gases and presence of thermal waters. The H2020 project FLOWERED (de-FLuoridation technologies for imprOving quality of WatEr and agRo-animal products along the East African Rift Valley in the context of aDaptation to climate change) wish to address environmental and health (human and animal) issues associated to the fluoride contamination in the African Rift Valley, in particular in three case study area located in Ethiopia, Tanzania and Kenya. FLOWERED aims to develop an integrated, sustainable and participative water and agriculture management at a cross-boundary catchment scale through a strong interdisciplinary research approach. It implies knowledge of geology, hydrogeology, mineralogy, geochemistry, agronomy, crop and animal sciences, engineering, technological sciences, data management and software design, economics and communication. The proposed approach is based on a detailed knowledge of the hydrogeological setting, with the identification and mapping of the specific geological conditions of water contamination and its relation with the different land uses. The East African Rift System (EARS) groundwater circulation and storage, today already poorly understood, is characterized by a complex arrangement of aquifers. It depends on the type of porosity and permeability created during and after the rock formation, and is strongly conditioned by the

  17. Assessment of in situ biodegradation of monochlorobenzene in contaminated groundwater treated in a constructed wetland

    International Nuclear Information System (INIS)

    Braeckevelt, Mareike; Rokadia, Hemal; Imfeld, Gwenael; Stelzer, Nicole; Paschke, Heidrun; Kuschk, Peter; Kaestner, Matthias; Richnow, Hans-H.; Weber, Stefanie

    2007-01-01

    The degradation of monochlorobenzene (MCB) was assessed in a constructed wetland treating MCB contaminated groundwater using a detailed geochemical characterisation, stable isotope composition analysis and in situ microcosm experiments. A correlation between ferrous iron mobilisation, decreasing MCB concentration and enrichment in carbon isotope composition was visible at increasing distance from the inflow point, indicating biodegradation of MCB in the wetland. Additionally, in situ microcosm systems loaded with 13 C-labelled MCB were deployed for the first time in sediments to investigate the biotransformation of MCB. Incorporation of 13 C-labelled carbon derived from the MCB into bacterial fatty acids substantiated in situ degradation of MCB. The detection of 13 C-labelled benzene indicated reductive dehalogenation of MCB. This integrated approach indicated the natural attenuation of the MCB in a wetland system. Further investigations are required to document and optimise the in situ biodegradation of MCB in constructed and natural wetland systems treating contaminated groundwater. - An integrated approach including isotope composition analysis and in situ microcosm experiments provided evidences for in situ biodegradation of MCB in a wetland system

  18. Assessment of in situ biodegradation of monochlorobenzene in contaminated groundwater treated in a constructed wetland

    Energy Technology Data Exchange (ETDEWEB)

    Braeckevelt, Mareike [Departments of Bioremediation, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany); Rokadia, Hemal [Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany); Imfeld, Gwenael [Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany)]. E-mail: gwenael.imfeld@ufz.de; Stelzer, Nicole [Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany); Paschke, Heidrun [Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany); Kuschk, Peter [Departments of Bioremediation, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany); Kaestner, Matthias [Departments of Bioremediation, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany); Richnow, Hans-H. [Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany); Weber, Stefanie [Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Saxonia (Germany)

    2007-07-15

    The degradation of monochlorobenzene (MCB) was assessed in a constructed wetland treating MCB contaminated groundwater using a detailed geochemical characterisation, stable isotope composition analysis and in situ microcosm experiments. A correlation between ferrous iron mobilisation, decreasing MCB concentration and enrichment in carbon isotope composition was visible at increasing distance from the inflow point, indicating biodegradation of MCB in the wetland. Additionally, in situ microcosm systems loaded with {sup 13}C-labelled MCB were deployed for the first time in sediments to investigate the biotransformation of MCB. Incorporation of {sup 13}C-labelled carbon derived from the MCB into bacterial fatty acids substantiated in situ degradation of MCB. The detection of {sup 13}C-labelled benzene indicated reductive dehalogenation of MCB. This integrated approach indicated the natural attenuation of the MCB in a wetland system. Further investigations are required to document and optimise the in situ biodegradation of MCB in constructed and natural wetland systems treating contaminated groundwater. - An integrated approach including isotope composition analysis and in situ microcosm experiments provided evidences for in situ biodegradation of MCB in a wetland system.

  19. Expectations for managing contaminated ground and groundwater: developing a common view of NDA and regulators - 16252

    International Nuclear Information System (INIS)

    Clark, Anna

    2009-01-01

    The management of contaminated ground and groundwater is a notable contributor to dealing with the challenge we face in cleaning up the legacy of the UK's civil nuclear industry in a safe, cost-effective and environmentally responsible manner. To facilitate this mission, the Nuclear Decommissioning Authority, Environmental Regulators and Safety Regulators are working together to develop common expectations for the management of contaminated ground and groundwater arising on and extending off nuclear licensed sites in the UK. The aims of this work are to: - set out shared expectations for land quality management, explaining any differing expectations where consensus is difficult; - interpret expectations to ensure they are clear and implementable, facilitating planning of programmes and deliverables; - provide a framework for dialogue against which progress in land quality management can be mapped; - promote positive action to manage land quality in a proportionate and sustainable manner to achieve consistent standards; and, - identify whether areas of the regulatory framework or NDA contractual requirements warrant review and propose improvements for consideration, as appropriate. This paper outlines the process currently ongoing to identify the best way of achieving these aims in a manner that avoids compromising the respective statutory obligations, duties and functions of each party. (author)

  20. Effect of Fluoride on Arsenic Uptake from Arsenic-Contaminated Groundwater using Pteris vittata L.

    Science.gov (United States)

    Zhao, Junying; Guo, Huaming; Ma, Jie; Shen, Zhaoli

    2015-01-01

    High-arsenic groundwater in inland basins usually contains high concentrations of fluoride. In the present study, the effects of fluoride on arsenic uptake by Pteris vittata and on arsenic transformation in growth media were investigated under greenhouse conditions. After P. vittata was hydroponically exposed to 66.8 μM As (V) in the presence of 1.05 mM F- in the form of NaF, KF, or NaF+KF for 10 d, no visible toxicity symptoms were observed, and there were not significant differences in the dry biomass among the four treatments. The results showed that P. vittata tolerated F- concentrations as high as 1.05 mM but did not accumulate fluoride in their own tissues. Arsenic uptake was inhibited in the presence of 1.05 mM F-. However, in hydroponic batches with 60 μM As (III) or 65 μM As (V), it was found that 210.6 and 316.0 μM F(-) promoted arsenic uptake. As(III) was oxidized to As(V) in the growth media in the presence and absence of plants, and F- had no effect on the rate of As(III) transformation. These experiments demonstrated that P. vittata was a good candidate to remediate arsenic-contaminated groundwater in the presence of fluoride. Our results can be used to develop strategies to remediate As-F-contaminated water using P. vittata.

  1. contaminant migration in a sand aquifer near an inactive uranium tailings impoundment, Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    Morin, K.A.; Cherry, J.A.

    1982-01-01

    An investigation of the movement of contaminated groundwater from inactive uranium tailings through a sand aquifer is being conducted at the Nordic Main tailings impoundment near Elliot Lake, Ontario. During 1979 and 1980, multilevel bundle-type piezometers were installed at several locations around the edge of the tailings impoundment. Chemical analysis of water samples from the bundle piezometers indicate that a major contaminant plume extends outward through a sand aquifer from the southeastern part of the Nordic Main impoundment dam. In the vincinity of the contaminant plume, the sand aquifer varies in thickness from about 9 to 15 m. The plume has two distinct segments, referred to as the inner core and the outer zone. The inner core, which has a pH of 4.3-5.0 and extends about 15 m from the foot of the tailings dam, contains several grams per litre of iron and sulfate, and tens of pCi/L of 226 Ra and 210 Pb. Water levels in piezometers within the inner core show that groundwater is moving horizontally, away from the tailings impoundment, with a velocity of up to several hundred metres per year. The outer zone, which extends a few hundred metres downgradient from the dam, is characterized by hundreds to thousands of milligrams per litre of iron and sulfate, less than 15pCi/L of 226 Ra, and a pH greater than 5.7. Comparison of 1979 and 1980 data shows that the front of the inner core is advancing a few metres per year, which is less than a few percent of the groundwater velocity. This retardation of movement of the inner core is caused by neutralization of the acidic water as a result of dissolution of calcium carbonate in the sand. With the rise in pH, precipitation of iron carbonate and possibly some iron hydroxide occurs and the contaminants of main concern such as 226 Ra, 210 Pb, and uranium are removed from solution by adsorption or coprecipitation

  2. In situ treatment of mixed contaminants in groundwater: Review of candidate processes

    International Nuclear Information System (INIS)

    Korte, N.E.; Siegrist, R.L.; Ally, M.

    1994-10-01

    This document describes the screening and preliminary evaluation of candidate treatment for use in treating mixed contaminants volatile organic compounds (VOCs) and radionuclides in groundwater. Treating mixed contaminants presents unusual difficulties. Typically, VOCs are the most abundant contaminants, but the presence of radionuclides results in additional health concerns that must be addressed, usually by a treatment approach different from that used for VOCs. Furthermore, the presence of radionuclides may yield mixed solid wastes if the VOCs are treated by conventional means. These issues were specifically addressed in the evaluation of candidate treatment processes for testing in this program. Moreover, because no research or early development of a particular process would be performed, the technology review also focused on technologies that could be readily adapted and integrated for use with mixed contaminants. The objective is to couple emerging or available processes into treatment modules for use in situ. The three year project, to be completed in September 1996, includes a full-scale field demonstration. The findings reported in this document encompass all activities through the treatment process evaluations

  3. In situ treatment of mixed contaminants in groundwater: Review of candidate processes

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.E. [ed.] [Oak Ridge National Lab., Grand Junction, CO (United States); Siegrist, R.L. [ed.] [Oak Ridge National Lab., TN (United States); Ally, M. [and others

    1994-10-01

    This document describes the screening and preliminary evaluation of candidate treatment for use in treating mixed contaminants volatile organic compounds (VOCs) and radionuclides in groundwater. Treating mixed contaminants presents unusual difficulties. Typically, VOCs are the most abundant contaminants, but the presence of radionuclides results in additional health concerns that must be addressed, usually by a treatment approach different from that used for VOCs. Furthermore, the presence of radionuclides may yield mixed solid wastes if the VOCs are treated by conventional means. These issues were specifically addressed in the evaluation of candidate treatment processes for testing in this program. Moreover, because no research or early development of a particular process would be performed, the technology review also focused on technologies that could be readily adapted and integrated for use with mixed contaminants. The objective is to couple emerging or available processes into treatment modules for use in situ. The three year project, to be completed in September 1996, includes a full-scale field demonstration. The findings reported in this document encompass all activities through the treatment process evaluations.

  4. Reactive barrier technologies for treatment of contaminated groundwater at Rocky Flats

    International Nuclear Information System (INIS)

    Marozas, D.C.; Bujewski, G.E.; Castaneda, N.

    1997-01-01

    The U.S. Department of Energy (DOE) Office of Science and Technology Subsurface Contaminants Focus Area is supporting the investigation of reactive barrier technologies to mitigate the risks associated with mixed organic/radioactive waste at several DOE sites. Groundwater from a small contaminated plume at the Rocky Flats Environmental Technology Site (RFETS) is being used to evaluate passive reactive material treatment. Permeable reactive barriers which intercept contaminants and destroy the VOC component while containing radionuclides are attractive for a number of reasons relating to public and regulatory acceptance. In situ treatment keeps contaminants away from the earth's surface, there is no above-ground treatment equipment that could expose workers and the public and operational costs are expected to be lower than currently used technologies. This paper will present results from preliminary site characterization and in-field small-scale column testing of reactive materials at RFETS. Successful demonstration is expected to lead to full-scale implementation of the technology at several DOE sites, including Rocky Flats

  5. Prediction of Groundwater Arsenic Contamination using Geographic Information System and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Md. Moqbul Hossain

    2013-01-01

    Full Text Available Ground water arsenic contamination is a well known health and environmental problem in Bangladesh. Sources of this heavy metal are known to be geogenic, however, the processes of its release into groundwater are poorly understood phenomena. In quest of mitigation of the problem it is necessary to predict probable contamination before it causes any damage to human health. Hence our research has been carried out to find the factor relations of arsenic contamination and develop an arsenic contamination prediction model. Researchers have generally agreed that the elevated concentration of arsenic is affected by several factors such as soil reaction (pH, organic matter content, geology, iron content, etc. However, the variability of concentration within short lateral and vertical intervals, and the inter-relationships of variables among themselves, make the statistical analyses highly non-linear and difficult to converge with a meaningful relationship. Artificial Neural Networks (ANN comes in handy for such a black box type problem. This research uses Back propagation Neural Networks (BPNN to train and validate the data derived from Geographic Information System (GIS spatial distribution grids. The neural network architecture with (6-20-1 pattern was able to predict the arsenic concentration with reasonable accuracy.

  6. Intrinsic bioremediation of MTBE-contaminated groundwater at a petroleum-hydrocarbon spill site

    Science.gov (United States)

    Chen, K. F.; Kao, C. M.; Chen, T. Y.; Weng, C. H.; Tsai, C. T.

    2006-06-01

    An oil-refining plant site located in southern Taiwan has been identified as a petroleum-hydrocarbon [mainly methyl tert-butyl ether (MTBE) and benzene, toluene, ethylbenzene, and xylenes (BTEX)] spill site. In this study, groundwater samples collected from the site were analyzed to assess the occurrence of intrinsic MTBE biodegradation. Microcosm experiments were conducted to evaluate the feasibility of biodegrading MTBE by indigenous microorganisms under aerobic, cometabolic, iron reducing, and methanogenic conditions. Results from the field investigation and microbial enumeration indicate that the intrinsic biodegradation of MTBE and BTEX is occurring and causing the decrease in MTBE and BTEX concentrations. Microcosm results show that the indigenous microorganisms were able to biodegrade MTBE under aerobic conditions using MTBE as the sole primary substrate. The detected biodegradation byproduct, tri-butyl alcohol (TBA), can also be biodegraded by the indigenous microorganisms. In addition, microcosms with site groundwater as the medium solution show higher MTBE biodegradation rate. This indicates that the site groundwater might contain some trace minerals or organics, which could enhance the MTBE biodegradation. Results show that the addition of BTEX at low levels could also enhance the MTBE removal. No MTBE removal was detected in iron reducing and methanogenic microcosms. This might be due to the effects of low dissolved oxygen (approximately 0.3 mg/L) within the plume. The low iron reducers and methanogens (soil) observed in the aquifer also indicate that the iron reduction and methanogenesis are not the dominant biodegradation patterns in the contaminant plume. Results from the microcosm study reveal that preliminary laboratory study is required to determine the appropriate substrates and oxidation-reduction conditions to enhance the biodegradation of MTBE. Results suggest that in situ or on-site aerobic bioremediation using indigenous microorganisms would

  7. Waste and cost reduction using dual wall reverse circulation drilling with multi-level groundwater sampling for contaminant plume delineation

    International Nuclear Information System (INIS)

    Smuin, D.R.

    1995-01-01

    This paper describes the drilling and sampling methods used to delineate a groundwater contaminant plume at the Paducah Gaseous Diffusion Plant (PGDP) during the Groundwater Monitoring IV characterization. The project was unique in that it relied upon dual wall reverse circulation drilling instead of the traditional hollow stem auger method. The Groundwater Monitoring program sought to characterize the boundaries, both vertically and horizontally, of the northeast plume which contains both 99 Tc and trichloroethene. This paper discusses the strengths and weaknesses of the drilling method used by investigators

  8. Groundwater contamination by chlorinated hydrocarbons in the soil vapour phase - risk assessment at a former dry cleaner site

    Energy Technology Data Exchange (ETDEWEB)

    Danzer, J. [Boden-und-Grundwasser GbR, Sonthofen (Germany)

    2002-07-01

    Chlorinated hydrocarbons, e.g. Perchloroethene (PCE) were commonly used for dry cleaning purposes among other ones. Since they have a significant toxic potential they impose a serious risk to groundwater quality. Due to their physico-chemical properties - particularly high volatility and medium to high water solubility - and their low biodegradation potential they are highly mobile within the unsaturated soil (vapour phase) as well as within the groundwater. This poster (paper) presents data and calculations of a consultant's ''virtual every day'' work in order to assess the risk of groundwater contamination at a former dry cleaner site. (orig.)

  9. Ion exchange technology in the remediation of uranium contaminated groundwater at Fernald

    International Nuclear Information System (INIS)

    Sutton, Chris; Glassmeyer, Cathy; Bozich, Steve

    2000-01-01

    Using pump and treat methodology, uranium contaminated groundwater is being removed from the Great Miami Aquifer at the Fernald Environmental Management Project (FEMP) per the FEMP Record of Decision (ROD) that defines groundwater cleanup. Standard extraction wells pump about 3900 gallons-per-minute (gpm) from the aquifer through five ion exchange treatment systems. The largest treatment system k the Advanced Wastewater Treatment (AWWT) Expansion System with a capacity of 1800 gpm, which consists of three trains of two vessels. The trains operate in parallel treating 600 gpm each, The two vessels in each train operate in series, one in lead and one in lag. Treated groundwater is either reinfected back into the aquifer to speed up the aquifer cleanup processor discharged to the Great Miami River. The uranium regulatory ROD limit for discharge to the river is 20 parts per billion (ppb), and the FEMP uranium administrative action level for reinfection is 10 ppb. Spent (i.e., a resin that no longer adsorbs uranium) ion exchange resins must either be replaced or regenerated. The regeneration of spent ion exchange resins is considerably more cost effective than their replacement. Therefore, a project was undertaken to learn how best to regenerate the resins in the groundwater vessels. At the outset of this project, considerable uncertainty existed as to whether a spent resin could be regenerated successfully enough so that it performed as well as new resin relative to achieving very low uranium concentrations in the effluent. A second major uncertain y was whether the operational lifetime of a regenerated resin would be similar to that of a new resin with respect to uranium loading capacity and effluent concentration behavior. The project was successful in that a method for regenerating resins has been developed that is operationally efficient, that results in regenerated resins yielding uranium concentrations much lower than regulatory limits, and that results in

  10. 100-D Area In Situ Redox Treatability Test for Chromate-Contaminated Groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Mark D.; Vermeul, Vincent R.; Szecsody, James E.; Fruchter, Jonathan S.

    2000-10-12

    A treatability test was conducted for the In Situ Redox Manipulation (ISRM) technology at the 100 D Area of the U. S. Department of Energy's Hanford Site. The target contaminant was dissolved chromate in groundwater. The ISRM technology creates a permeable subsurface treatment zone to reduce mobile chromate in groundwater to an insoluble form. The ISRM permeable treatment zone is created by reducing ferric iron to ferrous iron within the aquifer sediments, which is accomplished by injecting aqueous sodium dithionite into the aquifer and then withdrawing the reaction products. The goal of the treatability test was to create a linear ISRM barrier by injecting sodium dithionite into five wells. Well installation and site characterization activities began in spring 1997; the first dithionite injection took place in September 1997. The results of this first injection were monitored through the spring of 1998. The remaining four dithionite injections were carried out in May through July of 1998.These five injections created a reduced zone in the Hanford unconfined aquifer approximately 150 feet in length (perpendicular to groundwater flow) and 50 feet wide. The reduced zone extended over the thickness of the unconfined zone. Analysis of post-emplacement groundwater samples showed concentrations of chromate, in the reduced zone decreased from approximately 1.0 mg/L before the tests to below analytical detection limits (<0.007 mg/L). Chromate concentrations also declined in downgradient monitoring wells to as low as 0.020 mg/L. These data, in addition to results f